INSTALLATION OF SOLAR KILN AT THE

FOREST RESEARCH INSTITUTE AT YEZIN, BURMA

FPL-SUNY Collection Agreement FP-82-0417 FPL-FAO Collection Agreement FP-82-0425

SERVICE REPORT

By

William Simpson Consultant in Drying

August 23 - September 16, 1982

Food and Agriculture Organization of the United Nations State University of New York College of Environmental Science and Forestry U. S. Department of Agriculture, Forest Service, Forest Products Laboratory

TABLE OF CONTENTS

Introduction

Trip Report

Solar Kiln Components

Solar Kiln Operation

Solar Kiln Maintenance

Suggestions for Solar Drying Research

Appendix A--Correspondence and Agreements Establishing

Solar Kiln Project

Appendix B--Technical Note Describing FPL Solar Kiln Design

Appendix C--Description of Sri Lanka Solar Kiln Project

Appendix D--Acknowledgement of Delivery of Solar Kiln Blueprints

Appendix E-Photo of 11 Boxes Containing Solar Kiln Parts

Awaiting Shipment to Burma

Appendix F--Instructions Left at FRI for Installation of

Kiln Controls, Initial Check-Out, and Initial Kiln Test Run

Appendix G--Letter from Dr. Wylie Confirming That the Solar Kiln

Is Operational

Appendix H-List of Solar Kiln Components and Suppliers

Appendix I--Solar Kiln Operating Instructions

Appendix J--Solar Kiln at Forest Research Institute, Yezin, Burma

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INTRODUCTION

This report covers activities associated with the planning and construction

of a solar dry kiln at the Forest Research Institute (FRI) at Yezin, Burma.

The report includes correspondence and agreements that established the project,

a report of the trip to Yezin made by the author to help build the kiln,

descriptions of the kiln and its operation, and some suggestions on solar

drying research.

Purpose of the Assignment

The project was initiated by a request from Dr. Charles Larson, Director,

Burma Project to Dr. Robert Youngs, Director, Forest Products Laboratory (FPL),

requesting assistance in building a solar dry kiln at FRI (Appendix A). The

project was established under two separate Collection Agreements. In Collection

Agreement FP-82-0417 between FPL and SUNY Research Foundation, terms were

defined for the technical assistance of FPL specialists. In the other Collection

Agreement, FP-82-0425 between FPL and Food and Agriculture Organization of the

United Nations, funds were provided for the purchase of kiln components and their

shipment to Burma. The FPL-SUNY agreement set forth the terms of the technical

services of FPL and two consultants, William Simpson and John Tschernitz.

These services were:

1. Adaptation of the FPL solar kiln design for use in Burma.

2. Provision of blueprints, operating instructions, and other technical

details of the kiln.

3. On-site technical assistance in construction and initial start-up.

4. Oversee purchase and shipment of kiln parts to Burma.

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The FPL-FAO agreement provided the funding authorization for the solar

kiln components, and set forth the requirement that FPL package the kiln

components for shipment to Burma.

Because of personal reasons John Tschernitz could not make the trip to

Burma. The FPL-SUNY Collection Agreement was adjusted to reflect this

change (Dr. Geis's letter of November 15, 1982, Appendix A).

Background of FPL Solar Kiln Design

FPL's recent solar drying activities began in 1975 when the U. S. Agency

for International Development requested that FPL study the feasibility of

low-cost solar drying technology for small-to-medium size wood products

industries in tropical developing countries. FPL's conclusion was that solar

drying appeared feasible, and a kiln design was proposed. A 1000 board foot

prototype of the design was built at Madison, Wisconsin, and has been operated

during the summers since 1977. This experience pointed out several areas for

improvement in the design. Appendix B is a Technical Note describing the

design.

In 1980 the USAID Mission in Sri Lanka requested FPL technical assistance

in building the 1000 board foot kiln at a furniture factory in Sri Lanka.

The assistance was granted and the solar kiln was built in February, 1981.

The project is described in Appendix C. This kiln has been operating

successfully since installation, and the users are requesting a project to

enlarge the design to meet more of their production needs.

As part of the SUNY-FAO project, the FRI staff member in charge of

drying research, U Win Kyi, is studying for two years at Virginia Polytechnic

Institute and State University. As part of that study, Win Kyi spent 2-1/2

months at FPL during the summer of 1982. During his stay he learned how to

operate the FPL solar kiln, which is identical to the one installed at FRI,

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and conducted a solar drying experiment that will form the basis for his

Master's thesis.

TRIP REPORT

This section of the report covers the trip made by the author to the

Forest Research Institute at Yezin, Burma. The purpose of the trip was to

help install the solar kiln at the Institute. Enroute to Burma I stopped

briefly in Sri Lanka to inspect the solar kiln that was installed at a

furniture factory about 18 months ago, This inspection showed that the kiln

has been performing well for 18 months, and is still in good condition. As

a result of this inspection, I saw no reason to change any of the design

details of the FRI solar kiln, and expect it to also be successful.

I arrived in Rangoon on August 24. Aubrey Wylie, Chief Technical Advisor

of the Forest Research Institute Project met me at the airport. We attempted

the 250 mile trip from Rangoon to Yezin the next morning. But because of

heavy rains and flooding, the road and railroad were impassable. We finally

made the trip on August 28.

The project was organized so that FPL would first send blueprints and

other technical information on the kiln. We sent these on September 4, 1981,

and Dr. Wylie received them later in September (Appendix D). We then would

ship kiln components from FPL to FRI so that much of the basic kiln construction

could be completed before my arrival. Then during my 2 - 3 week stay I

would help finish the kiln and put it into operation. We shipped 11 boxes

of components by air freight on June 10 (Appendix E). The ETA in Rangoon

was June 17. The boxes arrived at Yezin on August 4. Because of delays in

equipment delivery to FPL, a final box containing electric motors, humidistats,

and a control panel did not leave FPL until late July. The ETA in Rangoon

was August 14.

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When I arrived at FRI, I was pleased with progress on the kiln. We

owe this good progress to the efforts of Dr. Carl de Zeeuw of SUNY. Without

his determined and concentrated effort, I don't believe much progress would

have been made,

The drying chamber and the foundation for the collector were complete

when I arrived. Most of the duct work was either in place or ready to set in

place. When we shipped kiln components from FPL we made the shipping boxes

with 1/2 inch, exterior grade, preservative-treated plywood. The idea was to

then use the plywood for interior sheathing. This worked out well. There

was no damage to the plywood during shipment.

During my first two weeks at FRI we installed the humidifier and water

line, fabricated fan frame supports and installed the frames and baffles,

installed one humidistat, installed the remainder of the solar heat ducts,

built an instrument shed, brought an electric line to the kiln, installed

sand and charcoal in the collector, and installed the collector cover.

On September 9 the kiln was complete except for the motors and control

panel. The construction went well and I am pleased with the quality of the

work. As of that date the final box containing the motors and control panel

had not arrived. Several days later a trace initiated by SUNY confirmed that

the box was not in Rangoon and no definite ETA could be established. This

posed a dilemma for me, I wanted to see the kiln in operation before I left,

but with no definite date for arrival of the box I probably would have had

to extend my stay by at least several weeks. This would have been considerably

beyond the agreed upon 2 - 3 week stay, and I decided I couldn't remain on an

indefinite basis. Therefore, I made arrangements to leave on September 16.

Then I knew I would be leaving before the motors and panel came, I

prepared some additional instructions (Appendix F). I wrote a detailed

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procedure for installation of the motors and hook up of the control panel,

initial check out of the control system, and a trial kiln run drying lumber.

This is in addition to an operating manual already prepared. I discussed

the electrical connections with the Construction Corporation electrician,

and he understood what needed to be done.

I also discussed my detailed instructions with two FRI staff members.

U Soe Tint was involved in the kiln construction, so he already understood

the operating principles. Shortly before I left, a decision was made that

U Soe Myint Thein would be acting in charge of drying research until

U Win Kyi returned from studying in the United States. I believe that these

two researchers will be able to make the kiln operational. I will be available

to answer any questions or help solve any problems that arise.

On November 29, I received a letter from Dr. Wylie, dated November 11,

in which he stated that the kiln controls had been installed and function

properly (Appendix G). Preparations were being made for the first kiln run.

SOLAR KILN COMPONENTS

The various kiln building materials and components are listed in

Appendix H in the form of USDA purchase orders. The supplier and cost

of each item is included for reference if replacement parts are needed.

SOLAR KILN OPERATION

A set of operating instructions for the solar kiln are included in

Appendix I. These instructions include an overall description of how the kiln

operates, a description of the daily cycle of control events, a description

of the operating controls, a list of electrical switches and what they

control, a schematic diagram of the control panel and a list of control

panel switch settings for automatic or manual operational mode, and an

electrical wiring diagram. These operating instructions were left with..

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U Soe Tint before I left Yezin. A photograph of the completed kiln is

shown in Appendix J.

SOLAR KILN MAINTENANCE

The solar kiln will not require much maintenance, but some inspection

and maintenance will be required.

1. The collector cover must be kept clean to maximize collection of

solar energy. In the dry season in particular, sand and dust will

probably accumulate on the collector. The best way to clean the

collector is to flood the surface with water until the sand/dirt has

been flushed away. Then the excess water can be wiped away with the

sponges and squeegie provided. The collector cover should never be

wiped when it is dry because sand/dirt will scratch the surface and

reduce solar transmission.

2. The screens on the humidistats should be checked for corrosion

periodically. If the screens become plugged, ambient air will not

be able to reach the internal sensors.

3. The damper motor and hinges should be checked periodically for

operation. Periodic oiling of the hinges may be necessary.

4. The gates in the fence around the kiln should be kept closed at

all times. If children or animals walk on the collector cover,

they will probably break through it.

5. The kiln door should be checked periodically to see that it

opens and closes properly and fits tightly.

6. The fan blades should be checked periodically to see if they have

accidently been hit and damaged.

7. The solar blower belt should be checked for tension and breaks.

Spare collector cover and fan blades were sent with the original shipment.

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Other suggested spare parts are:

1. One of each of the two types of humidistats

2. DEKO differential temperature comparator

3. Damper motor

SUGGESTIONS FOR SOLAR DRYING RESEARCH

FRI is now equipped to carry out drying research. In addition to the

solar kiln they have a covered air drying shed. They are now in a position

to develop a systematic program of drying research built around identification

of commercially important or potentially important species, identification

of end uses that determine final moisture content and quality requirements

and then development of solar drying procedures as well as procedures for a

combination of air and solar drying.

In solar drying a major objective would be to develop kiln schedules

that minimize drying time and drying defects. The schedules would consist

of a step-by-step reduction in relative humidity, and may differ with

species and lumber thickness. Determination of drying time on a species and

thickness basis would also result from research on schedule development.

There are areas of Burma and times of the year when air drying is effective,

in fact, in some hot, dry areas it may be so effective as to create quality

problems resulting from excessively rapid drying in the early part of drying.

Investigations could thus include seasonal and geographical effects on air

drying and solar drying alone and in combination. In many situations air

drying from green to 20-30 percent moisture content followed by finish drying

in the solar kiln is a natural combination that could minimize both drying

time and capital expenditure for kilns,

For the future, FRI might consider the addition of a low-cost wood

residue burner to supplement the solar kiln. This would allow 24 hours per

day drying all year long. The external-collector solar kiln design is

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particularly well adaptable to supplemental energy compared to a greenhouse

solar kiln. The high heat losses from a greenhouse kiln make the use of

supplemental energy impractical. A large percentage of this energy would

be lost through the uninsulated, transparent surfaces of the drying chamber.

A well-insulated drying chamber is necessary for efficient use of

supplemental energy. In a solar kiln, a drying chamber that is separated and

capable of being isolated from the solar collector is required. The ducts

for moving heated air are already incorporated in the FRI kiln, and it would

not be difficult to join a wood energy source to those ducts.

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APPENDIX A--Correspondence and agreements e s t a b l i s h i n g

So la r Ki ln P r o j e c t

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STATE UNIVERSITY OF NEW YORK

COLLEGE OF ENVIRONMENTAL SCIENCE AND FORESTRY

SYRACUSE CAMPUS SYRACUSE, NEW Y O R K 1 3 2 1 0

School of Forestry

July 28, 1981 SYRACUSE CAMPUS SYRACUSE. N.Y. 13210 Dr. Robert L. Youngs, Director

Schools of: Forest Products Laboratory • Biology, Chemistry & Ecology U.S.D.A. Forest Service • Continuing Education North Walnut Street Box 5130 • Environmental and

Resource Engineering Madison, Wisconsin 53705

RECEIVED

JUL 30 1981

• Forestry

• Landscape Architecture Dear Dr. Youngs: 06468 Empire State

Paper Research Institute I am writing in reference to our telephone conversations lnstitute of Environmental this past May concerning our need for technical assistance in

Program Affairs

Polymer Research lnstitute developing a solar kiln drying facility in conjunction with our

Renewable Materials Institute FAO/UNDP Contract to establish a Forest Research Institute

U.S. Forest Service for the Government of Burma. The Institute is located at Cooperative Research Unit Yezin, a small community about 250 miles north of Rangoon near the

city of Pyinmana where the Burmese Government has been engaged

CRANBERRY LAKE CAMPUS for the past decade in developing from the ground up a center CRANBERRY LAKE, N. Y. 12927 for agriculture and forestry education and research. Dr. Aubrey

Charles Lathrop Pack E. Wylie, formerly with the Science and Education Administration Experimental Forest of U.S.D.A., is our Chief Technical Advisor in charge of the

Cranberry Lake project at Yezin. Biological Station

You indicated in our telephone discussions that you have ELLIS INTERNATIONAL two specialists at your Laboratory who could be made available to

LABORATORY help us with the solar kiln project at a cost of roughly $40,000.CLAYTON, N. Y. 13624 About half of this figure would cover the cost of the kiln and the

other half the cost of consultant services of the two specialists, NEWCOMB CAMPUS including travel costs to Burma. I now have word from Dr. WylieNEWCOMB, N. Y. 12852 that he wishes to move forward with this project. He has the

Archer & Anna Huntington funding for the kiln and has submitted a requisition for its Wildlife Forest

Adirondack Ecological Center purchase in the amount of $20,000 to FAO/Burma, attention Mr. J. M. Bryce, Senior Operations Officer. I am enclosing for your information a copy of the requisition and cover letter. You will

TULLY CAMPUS note that Dr. Wylie has instructed Mr. Bryce to coordinate with TULLY, N Y. 13159

me on purchase of the kiln. The cost of consultant services will Heiberg Memorial Forest be funded by our College from its Contract funds. Genetic Field Station

We are anxious to move forward with this solar kiln project WANAKENA CAMPUS as soon as possible. Hence, we would appreciate knowing if and WANAKENA, N. Y. 13695 when your specialists would be available to proceed with the

Forest Technician Program project. Especially, we would like to have a detailed breakdown of costs of the project covering consultant services and

WARRENSBURG CAMPUS equipment, together with your recommendations for handling the WARRENSBURG, N. Y. 12885 purchases and installation of the kiln and the payment of funds.

Charles Lathrop Pack Demonstration Forest

Summer Field Program

ESTABLISHED IN 1911 TO ADVANCE ENVIRONMENTAL SClENCE AND FORESTRY THROUGH INSTRUCTION • RESEARCH • PUBLIC SERVICE

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Dr. Robert L. Youngs, Director

Forest Products Laboratory

July 28, 1981

Page two

Dr. Wylie sent me a list of data covering climatic conditions at Yezin that he felt would be useful in determining the solar collection needs for the kiln. I am enclosing a copy of this data which is not very clear but hopefully will be of some use.

Dr. Wylie was to have written you for information on solar drying of lumber. He will need information, I am sure, on what will be needed in the way of local building materials ,and facilities in support of the solar kiln.

I shall plan to give you a call early next week. There will be questions, no doubt, that you or your colleagues will have regarding this project.

Sincerely,

Larson,Charles C. Project Director

CCL : saf encl.

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FOOD AND AGRICULTURE ORGANIZATION

OF THE UNITED NATIONS

Mr. J. M. Bryce 24th June 1981.

Senior Operations Officer (1/c Desk)

FAO, Rome, Italy.

Dear Mr. Bryce,

The U.S. Department of Agriculture, Forest Service, Forest Products Laboratory offers to supply a solar dry kiln package including equipment and materials (except local building materials) for construction and operation and complete technical service to install controls and begin operation. Dr. Charles C. Larson, College of Environmental Science and Forestry, sub-contractor for the FRI project is willing to provide funds to cover one half of the cost of this dry kiln pacaage, the consulting or technical service portion of $ 20,000. The purchase requisition enclosed is submitted to request that the equipment portion of the package be purchased with project equipment funds.

I understand that Dr. Larson can coordinate this dual-action purchase especially on matters of scheduling and delivery. Please let me know of anything more from here in regard to this purchase requisition.

Sincerely,

c.c.

Dr. Charles C. Larson

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STATE UNIVERSITY OF NEW YORK

COLLEGE OF ENVIRONMENTAL SCIENCE AND FORESTRY

SYRACUSE CAMPUS Cable Address SUNYCESF SYRACUSE, NEW YORK 13210 TELEX/TWX 7105410555

SYRACUSE CAMPUS SYRACUSE.N.Y.13210

Schools of: • Biology, Chemistry & Ecology • Continuing Education • Environmental and

Resource Engineering • Forestry • Landscape Architecture Empire State

paper Research Institute Institute of Environmental

Program Affairs polymer Research Institute Renewable MateriaIs Institute U.S. Forest Service

Cooperative Research Unit

CRANBERRY LAKE CAMPUS CRANBERRYLAKE, N.Y.12927

Charles Lathrop Pack Experimental Forest

Cranberry Lake Biological Station

ELLIS INTERNATIONAL LABORATORY

CLAYTON, N. Y. 13624

NEWCOMB CAMPUS NEWCOMB N. Y. 12852

Archer & Anna Huntington WiIdlife Forest

Adirondack Ecological Center

TULLY CAMPUS TULLY, N. Y 13159

Heiberg Memorial Forest Genetic Field Station

WANAKENA CAMPUS WANAKENA, N. Y. 13695

Forest Technician Program

WARRENSBURG CAMPUS WARRENSBURG,N. Y.12885

Charles Lathrop Pack Demonstration Forest

Summer Field Program

July 22, 1982

Dr. William T. Simpson

Project Leader

Improvements in Drying Technology

USDA Forest Service

Forest Products Laboratory

Box 5130

Madison, Wisconsin 53705

Dear Dr. Simpson:

I am writing in reference to your forthcoming assignment as

consultant in solar kiln technology to the Forest Research

Institute Establishment Project at Yezin, Burma. The terms

of this assignment are set forth in the Collection Agreement

(FP-82-0417) between the Research Foundation of State Univer

sity of New York, for and in conjunction w i t h this College,

and the Forest Products Laboratory. In addition, certain

conditions covering your travel to Yezin and your accommo

dations there have been described in a letter to you dated

April 29, 1982 from Dr. Charles C. Larson, Project Director

for our Burma Contract operation.

While Collection Agreement FP-82-0417 stipulates that you

retain your status as an employee of the Forest Products

Laboratory, we are pleased to extend to you the full cour

tesy of association w i t h the College of Environmental Science

and Forestry during the period of your consultancy at the

Forest Research Institute. Our project is jointly sponsored

by the Food and Agriculture Organization (FAO) of the United

Nations and the Socialist Republic of the Union of Burma.

Please feel free to make this relationship known to all

concerned parties during your important mission.

CONTINUED...

ESTABLISHED IN 1911 TO ADVANCE ENVIRONMENTAL SCIENCE AND FORESTRY THROUGH INSTRUCTION • RESEARCH • PUBLlC SERVICE

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Page 2

Dr. W. T. Simpson

I wish to take this opportunity to express our appreciation

for your willingness to undertake this consultancy. We

consider the successful development of the Forest Research

Institute at Yezin to be of critical importance to the

future of forestry in Burma, and thus it is that we welcome

the significant contribution that your professional staff

expertise can make toward this end.

Edward E . Palmer President

EEP /1c cc: Dr. D. F. Behrend

Dr. C. C. Larson Mr. P. F. Wiltsie Mr. H. J. Corr Mr. J. G. Bachhuber (FPL) Dr. J. W. Geis

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COLLECTION AGREEMENT FP-82-0417

between

The Research Foundation of State University of New York for and in conjunction with College of Environmental Science and Forestry

and

Forest Products Laboratory

U.S. Department of Agriculture, Forest Service

THIS AGREEMENT, made and entered into by and between the Research Foundation of

State University of New York on behalf of State University of New York, College

of Environmental Science and Forestry hereinafter referred to as the cooperator,

and the Forest Products Laboratory, U.S. Department of Agriculture, Forest

Service, hereinafter referred to as the Forest Products Laboratory, under the

provisions of 16 U.S.C. 1642,

WITNESSETH:

WHEREAS, the cooperator and the USDA, Forest Service are mutually interested in

having Bill Simpson and Joh Tschernitz of the Forest Products Laboratory pro

vide their technical assistance in developing a solar kiln drying facility in

conjunction with a previously entered into FAO/UNDP Contract between FAO and

The Research Foundation to establish a Forest Research institute for the Govern

ment of Burma. This institute is located at Yezin, 250 miles north of Rangoon.

NOW, THEREFORE, in consideration of the above premise, the parties hereto agree

as follows:

Research Foundation of State University

of New York

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A. THE COOPERATOR SHALL:

1. Contribute to the Forest Service Cooperative Work Fund in advance of

the travel the sum of $15,330 to cover salary and overhead cost. The

remittance shall be made payable to the USDA, Forest Service, and shall

be sent to the Collection Officer, P.O. Box 5130, Madison, Wis. 53705.

2. Compensate Bill Simpson and John Tschernitz directly for travel expenses

using normal purchasing procedures. These arrangements will be made

directly with Mr. Simpson and Mr. Tschernitz. As a matter of infor

mation, each individual will be provided with a pre-paid, round trip

airline ticket from Madison, Wis., a brief stop in. Sri Lanka, continuing

onto Yezin, Burma, and return. Estimated cost: $7,000.

Reimbursment for per diem expenses will be made directly to each indi

vidual at FAO approved rates and in response to travel vouchers sub

mitted upon completion of the trip.

Estimated cost: $3,000 for both.

THE FOREST PRODUCTS LABORATORY SHALL:

1. Deposit the cooperative contribution under Clause A-1 of this agreement

to a Forest Service Cooperative Work Fund and use such contribution to

pay salary and overhead costs.

2. Provide the services of Bill Simpson and John Tschernitz who have

expertise in solar kiln drying. Services will include adaptation of

FPL solar kiln design for use in Burma; provision of blueprints, oper

ating instructions, and other technical details of the kiln; and or,-site

The Research Foundation technical assistance in construction and initial start-up.

of State University of New York The Forest Service will provide workmen's compensation and other

appropriate benefits to Messrs. Simpson and Tschernitz.

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3. Obtain necessary approval from the Washington Office prior to Bill

Simpson's and John Tschernitz departure from Madison. This agreement

is contingent upon receiving such approval.

C. IT IS MUTUALLY AGREED AND UNDERSTOOD BY AND BETWEEN THE SAID PARTIES THAT:

1. The trip will include a brief stop in Sri Lanka so that Bill Simpson

and John Tschernitz can see how well the solar kiln built there in

February 1981 is performing, and determine If its performance suggests

any changes in the Burma kiln. This stop will not increase the cost of

airfare.

2. Some kiln component; and control instruments will have to be shipped

form the Forest Products Laboratory to Burma to insure that the ship

ment of parts is complete and correct. The cost of these items and

their shipment will be covered by FAO under separate agreements. The

Forest Product; Laboratory will oversee the purchase and shipment of the

items from Madison, Wisconsin to Burma.

3. This agreement in no way restricts the Forest Service from cooperating

with or receiving cooperation from other public and private agencies,

organizations, and individuals or from accepting contributions and

gifts for the development of research.

4. No contribution to the cooperative work funds provided herein or dona

tion or gift of any kind shall entitle the Cooperator, contributor, or

donor to any share in the results of the research other than that

enjoyed by the general public.

5. Nothing herein shall be construed as obligating the Forest Service to Research Foundation

of State University expend or as involving the United States in any contract or other of New York

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obligation for the future payment of money in excess of appropriations

authorized by law and administratively allocated for this work.

6. No Member of, or Delegate to, Congress or Resident Commissioner, shall

be admitted to any share or part of this agreement, or to any benefit

that may arise therefrom; but this section shall not be construed to

extend to this agreement if made with a corporation for its general

benefit.

7. Either party may terminate this Agreement by providing 60 days' written

notice: Provided that any funds on deposit will be available for ex

penses incident io closing cut the work beyond the period of written

notice. Unless terminated on written notice, this Agreement will ter

minate on September 30, 1982.

3. This Agreement shall be effective upon execution by both parties hereto

5. It is understood and agreed that Simpson and Tschernitz are and will

remain employees solely of the U.S. Forest Service during the course

of this agreement, and that the Forest Service shall be solely respon

sible for providing them with Workmen's Compensation, Fringe Benefits

and all other appropriate insurances.

IN WITNESS WHEREOF: the parties hereto have executed this Agreement as of the

last date written below:

Research Foundation of State University

T i t l e : A s s o c i a t e D i r e c t o r of New York

DATE: 1/12/82

COLLECTION AGREEMENT FP-82-0425

between

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

and

FOREST PRODUCTS LABORATORY

U.S. DEPARTMENT OF AGRICULTURE, FOREST SERVICE

THIS AGREEMENT, made and entered into by and between Food and Agriculture Organization of the United Nations, hereinafter referred to as the Cooperator, and the Forest Products Laboratory, U.S. Department of Agriculture, Forest Service, hereinafter referred to as the Forest Products Laboratory, under the provisions of 16 U.S.C. 1642.

WITNESSETH:

WHEREAS, the Cooperator and the USDA, Forest Service are mutually interested in having solar kiln components and construction materials sent to Rangoon, Burma, in coordination with the development of a solar kiln drying facility for the Government of Burma.

NOW, THEREFORE, in consideration of the above premise, the parties hereto agree as follows:

A. THE COOPERATOR SHALL:

1. Reimburse the Forest Products Laboratory for the costs of the kiln structure, instrumentation and assembling of follows:

Costs of kiln structure, instrumentation and

a. Kiln Structure: Lumber Plywood Insulation Sealants, coatings, roofing Miscellaneous hardware, electrical

and contingency

b. Kiln Controls: Fans and motors Blower with motor Ventilator Humidifier Collector cover (includes spares) Timer and relay Humid is tats Differential temperature controller

the facility. Costs are as

assembly:

US $ 525.00 US $ 575.00 US $ 225.00 US $ 250.00

US $ 1,000.00 US $ 2,575.00

US $ 600.00 US $ 360.00 US $ 200.00 US $ 1,000.00 US $ 1,200.00 US $ 150.00 US $ 200.00 US $ 100.00 US $ 3,810.00

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c. Operational Accessories: Moisture meter Balances (2 ) Sunshine duration recorder Recording pyranometer Anemometer Hygrothermogaphs (2) Plainimeter

d. Assembling Costs:

US $ 300.00 US $ 550.00 US $ 875.00 US $ 700.00 US $ 450.00 US $ 775.00 US $ 200.00 US $ 3,850.00

US $ 6,000.00

TOTAL : US $16,235.00

B.

C.

THE FOREST PRODUCTS LABORATORY SHALL:

1. Send a Bill for Collection to the cooperator covering the costs outlined in clause A.1. This bill shall reference Purchase Order Number DFO/BUR/72/004/1B09669 issued by the Cooperator on December 14, 1981, a copy of which is attached as appendix A and made a part hereto of this Agreement.

2. Package the materials listed in clause A.1. in a manner suitable for shipment to Burma as directed by the Cooperator or its agent.

IT IS MUTUALLY AGREED AND UNDERSTOOD BY AND BETWEEN THE SAID PARTIES THAT:

1. This agreement in no way restricts the Forest Service from cooperating with or receiving cooperation from other public and private agencies, organizations, and individuals or from accepting contributions and gifts f o r the development of research.

2. Nothing herein shall be construed as obligating the Forest Service to expend or as involving the United States in any contract or other obligation for the future payment of money in excess of appropriations authorized by law and administratively allocated for this work.

3. No Member of, or Delegate to, Congress or Resident Commissioner, shall be admitted to any share or part of this agreement, or to any benefit that may arise therefrom; but this section shall not be construed to extend to this Agreement if made with a corporation for its general benefit.

4. Results of this research may be published by the Forest Products Laboratory at its discretion. The F o r e s t P r o d u c t s L a b o r a t o r y w i l l n o t use the name of the Cooperator, nor any member of the staff of the Cooperator, in any publicity without prior written approval of an authorized representative of the Cooperator. The Cooperator will not use the name of Forest Products Laboratory, nor any member of the staff of the Forest Products Laboratory, in any publicity without prior written approval of an authorized representative of the Forest Products Laboratory.

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5. Either party may terminate this Agreement by providing 60 days' written notice. Unless terminated by written notice, this Agreement will terminate on September 30, 1982.

6. The Food and Agriculture Organization reserves the right to inspect the supplies called for under this agreement at any time and the Forest Products Laboratory will afford every facility for such inspection.

7. The Forest Products Laboratory will pack the goods with the best materials and with every care, in accordance with the normal commercial standards of export packing for this type of merchandise. Such packing materials used must be adequate to safeguard the goods while in transit. The Forest Products Laboratory will be responsible for any damage or loss which can be shown to have resulted from faulty or inadequate packing.

8. Neither party of the Agreement shall be held responsible for delay in the fulfillment thereof due to force majeure, strikes, lock-outs, war, civil unrest, or other factors outside its control.

9. Nothing contained in this Agreement shall be deemed a waiver, express or implied, of any privilege or immunity which the Food and Agriculture Organization may enjoy, whether pursuant to the Convention on Privileges or Immunities of the Specialized Agencies or any other convention or agreement, law, order or decree of an international or national character or otherwise.

10. This Agreement shall be effective upon execution by both parties hereto.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the last date written below.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

Date: MAY 6 1982

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November 15, 1982

Mr. John G. Bachhuber

Budget and Fiscal Officer

United States Department of Agriculture

Forest Service

Forest Products Laboratory

P.O. Box 5130

Madison, Wisconsin 53705

Re: 210-6160A/X

Dear John:

This letter references your Collection Agreement FP-82-0417, our Purchase Order 6160A-18438 and telephone discussions of earlier today. Following a review with Dr. Simpson of the Forest Products Laboratory, Dr. Charles C. Larson and I have determined that three-quarters of the technical services outlined in your Collection Agreement have been delivered to date. Since the solar kiln is now installed and operating in Yezin, we do not anticipate a need for additional service as part of this project. This situation developed because of the inability of Dr. Tschernitz to travel to Burma as previously scheduled. Our estimate of technical services recognizes that Dr. Tschernitz committed a substantial amount of effort to the project in advance of his scheduled departure and that such effort should be appropriately charged under the Collection Agreement.

Since $15,330 have been paid by the Research Foundation of State University of New York to the Forest Service under Collection Agreement FP-82-0417, a refund of 25% of the cost of technical services or $3,832.50 is now due. Please make your check payable to the Research Foundation of State University of New York, identify the payment as a refund under your Collection Agreement and our Purchase Order numbers and return it to my attention.

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Page Two Bachhuber Letter

We are pleased to report that the first test load of lumber is currently being dried in the solar kiln at Yezin. This achievement reflects very favorably on the Forest Products Laboratory and the outstanding service which its staff provided in support of this project.

cc: Dr. Simpson Dr. Larson Mr. Collamer Mr. Corr Mr. Mabie

JWG/tkm

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FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

UNITED STATES DEPARTMENT OF AGRICULTURE UNIVERSITIES, COLLEGES, AND ORGANIZATIONS COOPERATING

Washington, D.C. 20250

May 3, 1982

AMENDMENT I TO PROGRAM AND ITINERARY

Mr. Win Kyi

FAO Fellow - Burma

M.S. Degree in Forestry

VIRGIRIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY

D u r a t i o n : 24 Months Arrival Date in USA: September 13, 1981

Departure Date 'From USA: September 7 , 1983

September 13, 1981 t o See Program and Itinerary dated September 8, June 13, 1981 (Approx.) 1981 for Background and Objectives and

Program to June, 1981.

o / a June 1 4 , 1982 TRAVEL to Madison WI 53705

June 15 t o August 15, 1982 USDA Forest Service Forest Products Laboratory

Program CONTACT: William T. Simpson, Project Leader Forest Service Forest Products Lab. P.O. Box 5130

TEL (608) 264-5600

OBJECTlVE: To have Training and Experience with the Solar Dry Kiln which is a type of kiln that will be installed in Burma and which Mr. Kyi will be directly responsible for upon his return. His work there will also be fully integrated into the research for his M.S. Thesis.

o / a August 1 6 , 1982 Return to VPI, Blacksburg, VA 24061

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Win Kyi

CONTACT:

ACADEMIC ADVISOR

OBJECTIVE:

September 7, 1983

Dr. C. Stephen Scheneman,

Extension Specialist

VPI

108 Hutcheson Hall

Blacksburg, VA 24061

TEL (703) 961-6433

Dr. Christen Skaar

Forest Products

210 Cheathan Hall

TEL (703) 961-5560

Continue Program of Studies leading

to M.S. in Forestry

DEPARTURE HOMEFOR COUNTRY

INVOLVEDINTHEDEVELOPMENT,CONDUCT,ANDEVALUATIONOFTHISPROGRAM:

Ms. Irene Field, FAO/Rome, R.A. Nicolosi, FAO/Washington, The Colleges and Universities and Institutions named herein, and Dr. Joseph E. Hoffman, Program Specialist, USDA/ OICD/ITD, Room 3549-South Building, 14th and Independence Ave., S.W. Washington, D.C. 20250. TEL (202) 447-4300.

APPENDIX B--Technical Note describing FPL solar kiln design

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Solar Energy Vol. 22, pp 563-566

Pergamon Press Ltd., 1979 Printed in Great Britan

TECHNICAL NOTE

Solar-heated, forced-air, lumber dryer for tropical latitudes

JOHN L. TSCHERNITZ and WILLIAM T. SIMPSON Forest Products Laboratory,† U.S. Department of Agriculture. Forest Service, Forest Products Laboratory, P.O. Box 5130,

Madison WI 53705, U.SA.

(Received 9 November 1978; revision accepted 2 January 1979)

1. INTRODUCTION

Lumber to be used for most wood products requires drying before it can be manufactured into a stable finished product that will perform satisfactorily. There are two general methods of drying lumber: air drying and kiln drying. In air drying, lumber is merely stacked in the open (or occasionally in sheds) in such a way as to assure natural air circulation through the stacks. This method is slow (low temperature) and offers no control over temperature and relative humidity. This uncontrolled drying often causes cracking and distortion in the lumber if relative humidities are too low in the early stages of drying. In those stages, wood is most susceptible to damage due to the stresses (wood shrinks on drying) caused by severe moisture gradients from core to shell. Furthermore, particularly in areas where ambient relative humidity is high, wood cannot be brought to a low enough moisture content by air drying alone, because of the hygroscopicity of wood

Kiln drying offers a means to control temperature and relative humidity in drying. Temperature control provides a way to increase drying rate and to reach lower final moisture content levels. Relative humid:? control allows enough manipulation of drying rate to slow drying in critical stages where drying defects are most likely to occur.

The solar dryer described in this note is a prototype of a solar dryer design developed by the Forest Products Laboratory, U.S. Department of Agriculture, for the Agency for International Development, Department of State[1]. The purpose of the project was to ascertain the feasibility of using solar energy to improve drying of lumber processed by small and medium-sized operators in developing nations, and to propose a dryer design if feasible. The initial target country was the Republic of the Philippines. One conclusion of the study was that if solar dryers could be built lor no more than approx. U.S. $5000 (1977, with local fabrication) and could process at least 2.4 m3 (1000 board feet) per week, they would be economically feasible. A 9.4 m3 capacity dryer design was proposed, and a 2.4 m3 prototype was built for testing at the Forest Products Laboratory in Madison, Wisconsin.

One assumption which limits to some extent the general application of this design to all tropical areas was that electrical power was available. This degree of sophistication was encouraged by interested parties in the Philippines as there is a great need for wood drying kilns in the immediate environs of Manila where electrical power could be supplied. Therefore, forced-air circulation in the dryer and collector was chosen for this design, eliminating the many problems associated with natural-convection air flow.

†Maintained at Madison, Wisconsin, in cooperation with the University ofWisconsin.

‡3-M Corp., St. Paul, Minnesota. §Kalwall Corp., Manchester, New Hampshire.

1. SOLAR DRYER

Solar collector The prototype solar dryer is shown schematically in Fig. 1, and

Fig. 2 is an actual photograph. The collector is external to the drying chamber so that collector area and orientation are not limited by the geometry of the dryer. The collector is horizontal (except for a slight N-S drainage tilt) and is built into the ground. Manila, Philippines, the actual design location. is 14°N latitude, so horizontal orientation is only a slight compromise to allow the ease and low expense of building the collector in the ground.

Figure 3 is an end cross section (looking north in Fig. 1) of the collector. Around the perimeter of the collector and lengthwise down the center of the collector to within 1 m of the south end, preservative-treated wood sills were laid in the excavated ground. Concrete blocks (mortared). 0.2 m high, were laid on top of these sills and another treated wood sill on top of the blocks. The 0.28 m deep excavation was filled with sand to within approx. 0.15m of the top of the top sill. A layer of granulated charcoal about 1.25 cm thick was spread over the sand to act as an inexpensive heat-absorbing surface and heat transfer medium. In addition, the charcoal is an excellent insulator, reducing ground heat loss. The interior surfaces of the blocks and sill were painted with a flat-black selective coating (NEXTEL).‡ The collector cover spans the 1.2 m between the blocks and sills. The cover material is a single layer of fiberglass-reinforced polyester 0.1 cm thick (Sun-Lite Premium grade).§ Transmission is specified by the manufacturer at between 85 and 90 per cent [2].

The collector is 2.5 m wide by 7.6 m long with a cover-absorber spacing of 0.15 m. Because of overlap at the sills, the collector area is approx. 16 m2. Air circulation between the collector and dryer is traced by arrows in Fig. 1. Air is drawn from one side of the dryer, travels the 7.6 m down the west side of the collector, crosses over to the east side of the collector through :he 1 m long gap, down the east side of the collector and back into the dryer. A 373 W (1/2 h.p.) blower just inside the dryer at this re-entry point induces air flow through the collector, keeping the collector under negative pressures so that all air leakage is into the system at this point.

Drying chamber The drying chamber is approx. 2.7 m square by 3 m high, of

wood frame construction. The walls are framed with 3.8 x 8.9 cm construction lumber. From the inside to the outside the construction is: 1.25cm thick exterior-grade plywood, polyethylene vapor barrier, 3.8 x 8.9 cm studs with fiberglass insulation batts, 2.5 cm thick polystyrene sheet insulation, 1.6 c m thick exterior-grade plywood. The roof is similar except the rafters are 19 cm wide instead of 8.9 cm, the rafter space is filled with loose fiberglass insulation, and roofing paper is used on the outside. The overall heat transfer coefficients are 0.347 W/m2°K and 0.207W/m2°K (0.0611 and 0.0365Btu/hft2°F) for the walls and roof. Two 373 W (1/2 h.p.) overhead fans circulate air through the sucked lumber. Venting is through ceiling ducts located at each side of the fans.

563

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564 Technical Note

Fig. 1. Perspective view of collector and drying chamber: (A) Drying chamber; (B) Solar collector; (C) Blower to induce air flow through collector; (D) Hot air discharge to intern2 fans: (E) Internal fans, unidirectional; (F)

Humidistat for vent control; (G) Humidifier; (H) Vents; (I) Damper motor.

The capacity of the drying chamber is about 2.36 m3 of lumber. Operation The heated air that enters the chamber is discharged directly into A drying experiment was conducted where a comparison was overhead fans that circulate air through the stacked lumber. A made between air drying and solar drying 2.36 m3 groups of low-cost nylon-elementhumidistat (off-on) is used to activate a 2.9 cm thick northern red oak lumber (USA). The drying was damper motor for control of roof vents when the relative humi- done between 16 June and 9 August 1977. so the performance of dity in the drying chamber exceeds the level set for the particular :he solar dryer was similar to what would be expected in low-stage of drying. A 187W (1/4h.p.) spinning-disk humidifier, with latitude locations (solar insolation on a horizontal surface plus its own humidistat and low-head water supply, is used to increase climatic conditions). Air flow through the collector was about relative humidity in the dryer when necessary. 34 m3 min-1 [face velocity of200 m min-1). and air velocity through

Fig. 2. 2.4 m3 solar lumber dryer.

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Technical Note 565

Fig. 3. Cross-sectional view of south end of collector; ( A ) Fiberglass cover; (B) Air space for circulation; (C) Charcoal heat absorber; (D) Sand; (E) Ground line; (F) Concrete blocks (hollow core); (G) Preservative-treated wood sills; (H) Wooden battens.

the stack of lumber was about 60 m min-1. The blower was usually operated from approx. 8:00 am to 6:00 pm. After about 6:00 pm, very little solar energy was collected. However, wood is capable of storing considerable energy. In the temperature and moisture content range encountered in drying. the specific heat of the oak lumber will range from a high of about 0.6 early in drying to a low of about 0.35 near the end of drying. This corresponds to energy storage of about 6900 kJ°C-1 per charge (2.36 m3) early in drying and about 3100 kJ°C-1 per charge later in drying. Because of this storage, the internal fans and vents were left on for about 4 hr after the collector blower was turned off.

In typical hardwood lumber drying. the temperature is raised and relative humidity is lowered as the wood dries. Temperature control is not possible in this dryer, but with the humidistatcontrolled vents and atomizing humidifier the relative humidity can be controlled. Thus, a relatively good level of control was possible over the drying process. The initial moisture content of the lumber was 84 per cent (dry basis). The relative humidity control was at 80 per cent from 84 to 50 per cent moisture content, 50 per cent RH from 50 to 30 per cent moisture content, and 30 per cent RH from 30 to 9 per cent moisture content. Fan reversal was not necessary for uniform moisture content in the lumber.

3. RESULTS OF DRYING

The drying curves for both the solar- and air-dried lumber arc shown in Fig. 4. The lumber in the solar dryer dried from 84 to 9 per cent in 54 days. and the airdried lumber only dried to 20 per cent in 54 days. Each represents a total drying load of approx. 1000 kg of water. In contrast. a conventional modern lumber dry kiln wilt only require about 24 days to dry this species. This illustrates the benefit of a solar dryer, particularly in low-latitude tropical countries, where ambient relative humidity is so high that lumber cannot be air dried to a moisture content low enough for finished products that will be used in low-humidity environments. either local or export. In drying from 84 to 40 per cent moisture content, the drying rate of the lumber in the solar dryer was less than that of the lumber that was air dried. The control of relative humidity at 80 and 50 per cent in the dryer is the cause of the reduced drying rate. The decrease in drying rate in this stage was quite effective in maintaining the qualify of the solar-dried lumber. Drying stresses are very critical in the early stages of drying. and a high relative humidity maintains the shell of the hoards at a high moisture content. This reduces the core-to-shell moisture gradient an3 thus the stresses that could build up in the surface fibers and cause cracking. The air-dried lumber had a total number of surface cracks 3.5 times greater than the solardriedlumber.

The average daily solar radiation in Madison, Wisconsin. for the drying period (16 June-9 August) is about 257 W/m2 (1960 Btu/ft2/day). During the particular period of this experiment, the radiation was 265 W/m2 (2020 Btu/ft2/day).

Figure 5 contains data, for 1 day, of conditions in the dryer and collector that, although somewhat warm for Madison with a high of 35°C, is typical of what might exist in low-latitude locations. On the day depicted in Fig. 6 the radiation was 334 W/m2 (2540 Btu/ft2/day) measured at the dryer. The maximum collector temperature on that day, measured at the circulating air outlet, was 59°C. Maximum dryer temperature (lumber at 35 per cent moisture content) was 52°C. and relative humidity was controlled at 60 per cent.

Fig. 4. Comparison of air and solar drying of I-inch red oak in Madison. Wisconsin, in 1977. Radiation instrumentation: Radiometer: Eppley black and white pyranometer; Integrator: Eppley Model 411.

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Technical Eiote

Fig. 5. Typical diurnal cycle of drying conditions in solar dryer at low latitudes

After lumber is dried. it contains stresses that hare developed during drying and can cause problems in later processing steps (distortion). Lumber dried under low-temperature conditions. such as the cyclic (diurnal) conditions in a solar dryer. also contains these stresses. These stresses are commonly relieved in a steam-heated dryer by a conditioning period of high temperature (80°C) and high humidity (85 per cent). The high humidity could be obtained in the dryer with the humidifier, but the maximum temperature in the solar dryer is limited to about 50°C. Stress relief was attempted at 85 per cent relative humidity and with the typical diurnal cycle of temperatures-andalthough the required conditioning period was about 2 days instead of the usual 18-24hr at 80°C-thestresses were successfully relieved. This confirms earlier observations on tropical woods[3].

A complete analysis of the performance of this design is now being prepared. It would appear that an upper limit of 50 per cent more electrical power is consumed in the solar dryer than in a conventional dry kiln with equal capacity-30fan days (52 × 14/24 = 30) plus collector blower-vs24 fan days. It should be pointed out that the fan motors for this model dryer were over-designed for experimental purposes, and most certainly would be reduced relative to dryer capacity for the economical operation of a larger production unit.

The initial test of this prototype solar dryer was promising and showed that the basic concept of a low-cost, simply constructed solar dryer with modest controls. where the collector is not an

integral part of the drying chamber and is built into the ground in a very simple, inexpensive manner is a design concept worth pursuing. Additional studies are now being performed on other collector covers and modes of operation.

Acknowledgements -Theauthors wish to acknowledge the guidance and assistance of Commissioner Francisco N. Tamolang and staff of the Forest Products Research and Industries Development Commission of the Republic of the Philippines and Albert Morales, President of the Philippine Council of Furniture Manufacturers, in providing access to background information necessary to development of the design.

REFERENCES

1. J. L. Tschernitz and W. T. Simpson. Solar kilns: Feasibility of utilizing solar energy for drying lumber in developing countries. U.S. Forest Products Laboratory Final Report to U.S. Agency for International Development, FPL-AID-PASA TA (AG) 02-75 (1977).

2. American Society for Testing and Materials, Standard methods of test for solar energy transmittance and reflectance (terrestrial) of sheet metals. Method B. ASTM Stand. Desig. E 424-71. ASTM, Philadelphia (1973).

3. M. Chudnoff, E. O. Maldonado and E. Goytia, Solar drying of tropical hardwoods. USDA For. Serv. Res. Pap. ITF-2. Institute of Tropical Forestry, Rio Piedras, Puerto Rico (1966).

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APPENDIX C--Description of Sri Lanka Solar Kiln Project

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--

Low-technology dryer supplements air drying, limits defects

Low-cost solar dry kiln gets trual in Sri Lanka

Horana, Sri Lanka FOR DEVELOPING COUNTRIES with significant forest cover, processing logs into marketable wood products is taking on increasing importance. To avoid defects associated with wood shrinkage, timber drying can play a critical role in that processing.

Even for domestic markets, dry kilns can be justified in developing countries.

By William Simpson and John Tschernitz Guest Contributors They eliminate long air drying times and reduce moisture content to levels lower than can be attained with air drying.

But processors in many of these countries lack capital to build state-of-the-art commercial dry kilns. And the cost of fossil fuels to operate kilns is often prohibitive. For these reasons, solar dry kilns offer an attractive alternative.

Solar dry kilns can be built and operated quite inexpensively in labor-intensive societies, and no purchase of fuels is needed. Since many developing countries with forest resources lie in the tropics. solar energy and high ambient temperatures are available on a year-round basis.

The US Forest Products Laboratory in Madison, Wisconsin had designed and built a low-cost solar dry kiln when vis

servative used in treating the green wood to reduce this problem.

Before this project, Borwood had only an air drying shed. Lumber was held for about three months in an attempt to air dry from 60% down to 15% moisture content. A moisture content of between 12 and 15% is suitable for the moist Sri Lankan climate. But problems with distortion and cracking of finished furniture indicated that the moisture content of the air dried lumber was probably above 15%.

The solar kiln was built in February 1981. Initial tests showed that 2.5-cmthick rubberwood air dried to about 25% moisture content can be finish-dried in the solar kiln to 15% in less than a week. Borwood plans to operate the kiln in this manner, i.e. air dry from green moisture content of about 60% down to 25 to 30% (this should take 30 to 45 days), then finish-dry in the solar kiln to 14%. With this program, drying time can be shortened by about 50% and provide a final moisture content safely under 15%.

Kiln to be tested The kiln as constructed has a 1.6 m3

capacity. Since Borwood processes about 16 m3/week of rubberwood. this kiln only provides about 10% of its needs. The kiln, however, is intended to be a prototype that will demonstrate the principle of operation.

Borwood will observe the kiln’s performance and then consider scaling-up to meet its full production needs. If necessary, the kiln can be modified. substituting local materials and components for some that were imported from the us.

For more information about the solar kiln, contact William Simpson, US Forest Products Laboratory, Box 5130 Madison. Wisconsin 53705, USA.

T H E AUTHORS, William Simpson, a forest products technologist in charge of wood drying research at the US Forest Service Laboratory, and John Tschernitz, a chemical engineer also at the laboratory, were responsible for the solar dryer project from its inception and provided technical assistance during kiln installation.

13

ited by Hops Todd, director of Borwood Ltd, a subsidiary of the Industrial Development Board of Ceylon. Mr Todd saw the prototype dryer developed for low-latitude locations and thought it would have application in Sri Lanka. Upon return to his country, he contacted the local mission of US Agency for International Development and requested support to engage the Forest Products Laboratory in helping to build a solar kiln in Sri Lanka.

Rubberwood is dried A government enterprise, Borwood

Ltd is operated as a profit-making venture. It produces a line of institutional furniture (desks, chairs, tables) used primarily by schools and the military.

One of the major reasons Barwood was established was to utilize timber from rubberwood (Hevea braziliensis)

FEBRUARY 1982 WORLD WOOD

Workmen install the solar collector for the solar lumber dryer built in Horana, Sri Lanka. Because the collector is separate from the drying chamber, it can be sized to supply the requi red energydemand.

trees. Sri Lanka has about 240,000 ha of rubber plantations. When the trees stop producing commercial quantities of latex, after about 30 years. they are removed and new trees are planted. About 8,000 ha are harvested and replanted annually, making available approximately 16,000 m3 of rubberwood. While this may provide a continuous supply of rubberwood, it has not been well utilized. The wood is considered to have several inferior qualities, among them a severe susceptibility to stain and insect attack when freshly cut. Borwood’s trade name is derived from the boron salt pre

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1600-2

February 24, 1981

To : The Record

From : William T. Simpson

Subject: Trip Report--Travel to Sri Lanka from February 1, 1981 to February 1 4 , 1981

John Tschernitz and I traveled to Sri Lanka from February 1 - 1 4 , 1981 to give assistance in building a solar dry kiln. The project had its beginnings in 1977 when a Sri Lankan, Hope Todd, Director of Borwood Limited, Subsidiary of the Industrial Development Board of Ceylon, visited Forest Products Laboratory. He saw the solar dry kiln we had designed for loxi-latitude locations and thought that it would have application in Sri Lanka. When he returned to Sri Lanka, he contacted the local Agency for International to engage the Laboratory in a The Agency for International and after several false starts on here.

Development Mission and requested funds project to build a kiln in Sri Lanka.

Development (AID) decided to fund the project, the kiln was built in the trip reported

Borwood Limited is a government run enterprise. It was established with government funds, but is operated as a profit-making manufacturing plant. They produce a low cost line used primarily by schools and Borwood was established was to braziliensis) trees. Sri Lanka and when rubberwood trees no

of furniture (desks, chairs, tables, etc.) the military. One of the major reasons

utilize timber from rubberwood (Hevea has about 600,000 acres of rubber plantations, longer produce sufficient latex (about 30

years), they are removed and new trees planted. About 20,000 acres are harvested and replanted annually, with about ten million cubic fret of rubberwood available. Thus, there is a continuous supply of rubberwood, and it has not been well utilized because it i s considered by many to have inferior qualities. It does have one serious fault in that when freshly cut from the log it is very susceptible to stain and insect attack. The term Borwood comes from the preservative treatment with boron salts used to prevent this problem.

Before this project, Borwood had only air drying facilities. They were attempting to air dry to 15 percent moisture content (12 to 15 percent is ideal for their climate) and were holding lumber about three months to attempt to accomplish this. In conversations with various people, as

-36-

well as in our own observations, we could tell that the finished furniture

distorted after assembly, indicating that the air dried lumber was probably

above 15 percent.

Before going to Sri Lanka, we sent blueprints of the kiln and various

instructions on its construction and the suggestion that they begin

building before we arrived. We would then help them finish the construction

and put the kiln into operation. Despite all the problems in getting

the project underway, this scheme worked out very well. Todd had

assembled a team of about four young engineers for the project. They are

very enthusiastic about the project, and when we arrived they had the

kiln about three-fourths completed. In the first week we were there,

we helped them finish the kiln. At the start of the second week we

loaded the kiln with 1000 board feet of one-inch air dried (24 to 26 percent)

rubberwood. By Thursday of the second week the lumber was dried to 15

percent, thus demonstrating that the kiln operates as expected.

They plan to operate the kiln in the above manner, i.e., air dry from

initial (60 percent) moisture content down to 25 to 30 percent (this

should take one to one and one-half months), then finish dry in the solar

kiln to 15 percent in about five days. Thus, they will replace three

months of air drying to a questionable 15 percent with about one and one-half

months of a combination of air and solar drying to a definite 15 percent.

The kiln as constructed is 1000 board foot capacity and is a duplicate of

the Madison prototype except that the collector in the Sri Lanka kiln is

40 percent larger than in the Madison kiln. Borwood processes about

10,000 board feet of rubberwood per week, and, therefore, the kiln only

provides about ten percent of their needs. However, the kiln is intended

to be a prototype that will denonstrate the principles of how it works.

Thereafter, the kiln could be scaled up, local inaterials could be substi

tuted for some that were imported, and modifications could be made if

necessary. We have had discussions with Todd and the engineers on these

subjects and all indications are that they will closely observe the

performance of the kiln and then build more and/or larger kilns in the

future.

On Thursday of the second week (February 12) Todd held an open house to

coincide with the end of the first drying run. It was well attended, with

50 to 75 visitors from government, industry, universities, and the local

press. Among the attendees were the American Ambassador to Sri Lanka,

the Director of the U.S. AID Mission, and the Sri Lankan Minister of

Trade. Even though the project was small by the Mission's standards ($30,300

out of a $45,000,000 budget), they did seem somewhat impressed by the fact

that we successfully completed the project. On Friday, February 13, we

attended a press conference for the local press sponsored by the United

States International Communications Agency (formerly the United States

Information Services). Several articles on the kiln appeared in the

Colombo newspapers.

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3

In addition to drying lumber, there was interest in extending the concept

of the dryer to other commodities such as rubber, spices, tea, grain,

ceramics, tobacco, and copra.

We will be keeping in touch with Todd to follow the progress of the kiln

and how it works out for them.

Enroute to Sri Lanka, we stopped in Bangkok and visited Kasetsart

University (agriculture) . We talked to the faculty of the Wood Technology

department about problems in utilizing rubberwood. We learned that

rubberwood warps considerably during drying (we also observed this in

Sri Lanka). Pallets are the major outlet for rubberwood in Thailand.

also gave a seminar on solar drying to the faculty and graduate students of the Wood Technology Department.

cc: R. Youngs G. Lindell B. Bohannan J. Tschernitz

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I

APPENDIX D--Acknowledgement of Delivery of Solar Kiln Blueprints

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Thank you for the letter of September 4, 1981, the photos and

detailed blueprints.

ever an optimist, which is the only way to live here, I look

forward to an approval of a budget revision that will provide funds to

buy equipment. Our present difficulty was caused by an action that

was unforeseen, a result of a decision totally beyond my control.

It may be another month before the revision is approved.

There will be no problem in getting teak lumber. Can we use

teak lumber in place of plywood? We think it will be satisfactory.

will be trying to locate a source of plywood nearby. It is quite

difficult to find out from this location.

How long do you expect it will take for the shipment of kiln

equipment and construction materials to be delivered here after you

receive the order?

Patiently and eagerly I am waiting for the time when you will

arrive. The solar kiln is a rather important item for our forest

products research program.

Sincerely,

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I

Dear Dr. Wylie:

Enclosed are some more detailed blueprints of the solar kiln and also some photos. The four foot long treated posts shown beneath the foundation in print 1 probably are not necessary in Burma. we used them under our model here in Madison to prevent movement due to freezing and thawing of the ground. Your local buildingpractices would probably be the best guide for details of the foundation.

Note also that in the photos the power exhaust on our Madison kiln is shown down in one corner. When we first built our model, we had vents on top and built our instrument shed on the side shown in the photo. We found that venting was inadequate and changed to the power vent and fresh air intake shown. But the instrument shed made it impossible to center the vent on that wall as it should have been. We sould suggest a small instrument shed on the opposite wall. In addition to any instruments that might be used in there, it is also an ideal location for the electrical switches.

It is my impression from talking with people at Syracuse that it is unlikely that plywood and treated lumber are available locally. We could have plywood send from the United States, but I would wonder if it could be imported from a closer neighboring country to save on shipping.

Considering that the heartwood of teak is very durable (our references here indicate a 25 plus year life in contact with the ground) do you think it is feasible to get teak lumber locally?

We are still waiting to hear from Dr. Larson on details of funding the project.

Sincerely,

APPENDIX E--Photo of 11 Boxes Containing Solar Kiln Parts

Awaiting Shipment to Burma

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APPENDIX F--Instructions Left at FRI for Installation of

Kiln Controls, Initial Check-Out, and Initial

Kiln Test Run

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NOTES ON INSTALLATION OF CONTROLS

AND OPERATION OF SOLAR KILN

By

William Simpson (9/12/82)

The following items are in the box that has not yet arrived.

Quanti t y Item

2 1/2 hp, 2 speed electric motors for internal fan

1 1 / 2 hp, single speed electric motor for solar blower

1 Damper motor

3 Humidistats

1 Control panel

The internal wiring diagram and layout of the control panel are shown

in the operating instructions prepared by Tschernitz. To make the kiln

operational the following needs to be done:

1. Install the two fan motors and fan blades and check that air

direction from fans is east to west. Check that hook up for high

and low speeds conforms to switch position shown in Tschernitz's

diagram of control panel layout.

2. Install solar blower motor and check that air direction is out of

ducts toward fans. Tschernitz's diagrams show this to be a two

speed motor. However, it is only single speed and a choice will

have to be made of which switch position is the ON position. Motor

mounting bolts for all three 1/2 hp motors are in the box containing

the fan belts. The 2-1/2-inch pulley in this same box goes on the

blower motor shaft.

3. Install damper motor as shown in attached photos B and C.

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4. Instal l remaining humidistats on the in-place hanger. RH1 is

already in place. I brought an RH1 with me because there is a

possibility that there has been a mix up in the model number of the

three sent in the last box. RH1 is the most important humidistat

and the kiln can be operated usefully with only RH1. There i s a

possibility that all three of the humidistats in the box are RH2

and 3's or all RH1's. This should be checked by model number on

the inside of the housing when they arrive. The two different

humidistat models can be identified as follows:

Designation Honeywell Model Number

RH1 H 404A 1003

RH2 and RH3 H 404C 1019

If there are not at least two model H404C 1019 in the last box,

let us know if you need one or two and we will immediately send

them.

5. The humidifier was supposed to be 230 volt, but is only 115 volt.

Therefore, a step-down transformer must be used before it is

hooked up electrically. The construction corporation electrician

has one to loan until a permanent one can be purchased. RH3 will

have to be connected to the solenoid on the humidifier. (We will

not use the humidistat built into the humidifier because our

experience is that it does not operate satisfactorily.) The built-

in humidistat should be set at its maximum setting.

6. There are 9 electrical hook ups to be made from the control panel.

To fan 1 To RH2

To fan 2 To RH 3

To solar blower To damper motor

To RH1 To exhause fan

To humidifier

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7.

All nine of these wires from the control panel are labelled.

The thermostat for controlling ON/OFF of the kiln is located on

the control panel. The sensor must be led into the kiln and located

as shown in photo A. Care should be taken not to make a sharp bend

in the capillary tubing. The thermostat should be set at 90° F.

The instructions are attached.

8. The DEKO differential temperature controller is mounted on the

control panel and has two sensors that must be led to the proper

locations. One is the low temperature sensor and the other is the

high temperature sensor. The low temperature sensor is located in

the kiln as shown in photo B. The high temperature sensor is

located outside the drying chamber in the collector just before the

entrance to the solar blower duct. Drill a small hole in the

plywood cover and drop the sensor so that it i s about mid-way

between the charcoal and the level of the collector cover. Then

seal the hole. See Figure 1 in Tschernitz's instructions.

The two DEKO sensors will probably not be labelled high and low.

Therefore, you will have to warm each sensor separately to see

which one, when warmed, turns on the solar blower and opens the

damper. The differential temperature between the high and low sensors

should be about 4-5" F. This differential can be adjusted by a set

screw on the DEKO. You will have to check the differential with

thermometers.

9. The timer is located on the control panel. Considering the daylight

hours a t Yezin I suggest the ON time be set between 8 A.M. and 8 P.M.

Experience may suggest slight changes.

Initial Check-Out

1. Conduct check out between 8 A.M. and 8 P.M. after setting the timer.

2. Check operation of fan 1 and fan 2 in switch positions HIGH-OFF-LOW.

RH2 turned all the way to ON position.

3. Set switch S7 to by-pass DEKO. Check operation of solar blower using

switch 8. Make sure damper on air intake is open.

4. Set RH1 to OFF. Close switch 9 for exhaust fan check out. Decrease

setting of RH1 until ambient relative humidity is reached--a click

will be heard from the humidistat. The exhaust fan should then operate.

5. RH2 will shut off the kiln when the relative humidity in the kiln rises

above set-point. To check this, set RH2 to maximum setting (ON position

on dial) and switch 6 to open position. Have the fans and blower

operating. Decrease RH2 setting until humidistat clicks. The fans

and solar blower should shut off.

6. To check humidifier set switch S4A to open position, set RH3 to maximum

setting (ON), open water valve handle on humidifier. Decrease RH3 until

humidistat clicks. The humidifier should then operate.

7. Confirmation that the DEKO unit controls can be made by initially having

the two sensors at the same temperature and the solar blower switch S8

in the ON position. The damper should be closed. When the high

temperature sensor is warmed, the blower should turn on and the damper

motor should open the damper.

8. To check that the thermostat can control the kiln, heat or cool it above

and below 90° F and observe that the kiln is on above 90° F and off

below 90° F. This should be done outside the ON limits of the timer.

Ad just the timer temporarily for convenience of test.

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Test Run With Lumber

Load the kiln with nominal 1-inch thick lumber. Make kiln sample board

pockets for four 28-inch long samples on each side of the load. Cut eight

30-inch samples from eight different boards. Cut them a t least six inches in

from either end. Cross cut 1-inch long moisture sections from each end of

the sample boards and weigh them immediately. End coat, with silicone, the

two ends of the 28-inch sample boards and weigh them immediately. Oven dry

the 1-inch moisture sections for 24 hours at 104° C.

Make the sample pockets according to the following diagram: (Hand drawn

diagram included in the instructions that were left.)

When the moisture sections have been oven dried for 24 hours, weigh

them for oven dry weight and calculate their moisture content by the following

formula:

Moisture content = Green weight - oven dry weight x 100Oven dry weight

For example, if initial weight is 600 grams and oven dry weight i s 400 grams,

MC= 600 - 400 X 100 = 50%400

Average the two MC's of the moisture sections from the end of each sample

board. That value will be an estimate of the green moisture content of the

sample board. Knowing that initial MC, the oven dry weight of the sample

board can be calculated by rearranging the MC formula.

ODW =GW 1 + MC

100

For example, if the green weight of the sample board was 4000 grams when

the MC of the moisture section is 50%, the oven dry weight is:

ODW = 4000 = 2667 gms. 1 + 50

100

-50-

Now, with periodic weights of the sample boards during drying, the MC's a t

those times can be calculated from

MC = GW - ODW X 100 ODW

For example, when the weight of the sample board has fallen to 3500 grams,

the MC is :

MC = 3500 - 2667 X 100 = 31.2% 2667

These periodic weights of the eight sample boards should be recorded daily.

The solar kiln will allow automatic control of a drying schedule

consisting of a series of relative humidities corresponding to various levels

of moisture content. This allows maximum drying ra te with minimum defects.

One objective of FRI drying research should be to develop the best schedule

for each species and thickness. In the absence of a proven schedule, I will

recommend one for the initial trial.

The schedule to be followed is:

1. From green to 50 percent moisture content the relative humidity should

be controlled at 80%. To do this, set RH1 at 80%, RH2 all the way to ON,

and RH3 at 80%. There will be a dead band in the humidistats and the

operator should watch to ensure that the exhaust fan and humidifier do

not operate at the same time and thus fight each other. If this happens,

adjust RH3 to a higher setting so that they do not operate simultaneously.

2. From 50 to 30% moisture content, the relative humidity should be controlled

a t 50%. Set RH1 to 50%, RH2 about half way between 80% and ON, and RH3

a t 50%. Again, watch for simultaneous operation of the exhaust and the

humidifier, and if necessary increase RH3.

3. From 30 to 15% moisture content, the relative humidity should be controlled

a t 30%. Set RH1 to 30%, RH2 to 65%, and RH3 to OFF.

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A calibration check should be made on all of the humidistats. The

dial settings are only approximate, and they should be calibrated using one

of the hygrothermographs.

Maintenance of the Solar Kiln

Only minimum maintenance is required on the kiln. The collector cover

will require periodic observation and cleaning. In the dry season in

particular, if dust and sand build up, it should be cleaned. In cleaning

off sand and dirt, the cover should first be thoroughly flushed with large

quantities of water so that the abrasive sand is washed away. Once most

of the sand is flushed away, the cover can be dried with the squeegie and

sponges provided. The cover should never be wiped when it is dry. After

heavy rains it will also be necessary to wipe away excess water.

If the kiln is not used during your hot, sunny season from November 1982

to May 1983, I would suggest the collector be covered to avoid prolonged

heating of the collector with no circulation to reduce the temperature. I

don't know for sure, but this could accelerate deterioration of the cover

material. However, if you do this, there must be at least a six inch a i r gap

between the collector cover and the added cover so that moisture cannot become

trapped on the plastic. This will definitely accelerate deterioration.

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APPENDIX G--Letter from Dr. Wylie Confirming That the

Solar Kiln i s Operational

-53-

ORGANISATION DES NATIONS UNIES POUR ORGANIZACION DE LAS NACIONES UNIDAS L'ALIMENTATION ET L'AGRICULTURE PARA LA AGRICULTURA Y LA ALIMENTAClON

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

UNDP/FAO Project BUR/81/041 Forest Research I n s t i t u t e P.O. BOX 101, Rangoon, Burma,

Mr. William T. Simpson 11th November 1982

Project Leader

Improvements in Drying Technology

Forest Products Laboratory

P.O. Box 5130

Madison, WI 53705

U.S.A.

Dear Bill:

Glad to hear that you had a good trip from Burma. Also,

the information on the humidifier rewiring is well received,

The kiln controls are installed. All seem to function properly.

This week a load of "Leza" lumber is being sawn. Next, we will load the kiln and make a run. We don't foresee any problem.

The personal items that cane with the last carton include Tchernitz's shoes and clothes. What should we do with then?

I don't expect that he will be coming here.

We will let you know about the kiln operation. All is sunshine here now and will be for about 5 months. We should have plenty of energy.

Best wishes.

Sincerely,

Chief Technical Adviser.

-54-

APPENDIX H--List of Solar Kiln Components and Supplies

-55 -

APPENDIX I--Solar Kiln Operating Instructions

-84 -

OPERATION OF FPL FORCED AIR SOLAR DRYER

FOREST RESEARCH INSTITUTE, YEZIN, BURMA

By

J. L. TSCHERNITZ

I. Dryer Principles

The dryer has been designed to operate automatically with continuous

electric power supply along with manual override. A range of operating

variables can be changed by manipulation of set points. This provides

for the scheduled drying of even refractory hardwoods.

The air circulation in the system is essentially two intersecting

loops, one through the collector, the other through the wood package

(See Fig. 1); the later is approximately twice the volume of the

former. The exhauster (K-Fig. 1) removes air (containing evaporated

water) from the air leaving side (high humidity) of the wood package.

The makeup air enters (J-Fig. 1) the system through the collector

(B-Fig. 1). This is done for three reasons: 1) by lowering the temper

ature in the collector, heat losses are decreased; 2) a f te r the solar

energy input no longer maintains the collector above dryer temperatures,

the stored energy (collector above ambient temperature) can be used

to preheat the incoming air; 3) the ambient temperature and less humid

air can purge the collector of high humidity dryer air and thereby prevent

or reduce condensation within the collector, which will increase its

efficiency (energy i s required to re-evaporate water at the beginning

of the next cycle).

- 85 -

Automatic control of the solar dryer is desirable (at the least

possible cost) in order to accommodate the intermittent delivery of

solar energy to the collector; variable relative humidities (RH)

within the drying chamber which will depend upon the ambient humidity,

temperature in the chamber, and the rate of drying of the wood for

upwards of 14 hours of dryer operation per day. Without such controls,

almost continuous manual observation would be needed to approach the

quality and efficiency of drying attainable with automatic control. Such

controls provide for collector use by means of a differential thermal

switch when sufficient energy has been captured; by means of a humidistat

switch (RH1), venting can be intermittent by need, not continuous with

subsequent overventing. Controlled venting not only increases thermal

efficiency of the dryer, but also permits scheduled drying, i.e., high

relative humidities at the beginning of the drying schedule and low

controlled humidities at the end. A second humidistat (RH2) is used

to establish a maximum relative humidity above which the dryer will not

operate: this might happen during long periods of low solar input and

high humidities, i.e., rainy periods, particularly important when the

wood is below 20 percent moisture content. A third humidistat (RH3) has

two functions: 1) controls the disk atomizer for conditioning at the end of

the drying run, e.g. RH3 set at 80%, the disk atomizer would be off above 80%

and on below; 2) for refractory woods at intermediate moisture contents it

may be desirable to raise the relative humidity in the drying chamber in

order to prevent and/or reduce degrade.

II. Sequence of Operation, 24 Hour Cycle

The sequence of events for one 24 hour period is as follows:

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0000 - 0800 hours

1. Timer (F-Fig. 2 ) cuts power to the control relay.

0800 hours

2 . Timer closes the control relay (G-Fig. 2) if the relative

humidity in the dryer is below RH2, Fig. 2 (Fl-Fig.