Climbing Film Evaporator Design Laboratory - Sarkeys E111

September 29th, October 6th, 13th & 20th, 2015

CHE 4262-002 Group E

Eric Henderson

Nadezda Mamedova

Andy Schultz

Xiaorong Zhang

1

Table of Contents

Executive Summary (Nadezda Mamedova)………... ……………………………….……………2

Introduction (Nadezda Mamedova)……………………….…..…..……………………………….3

Theory (Nadezda Mamedova)………….…..…..………………………………………………….4

Design Plan (Eric Henderson)….…..…...…………………………………………………………6

Experimental Plan (Andy Schultz)………….…..…..….………………………..……………..….8

Apparatus (Andy Schultz)….………………………………………………..………..……..…....10

Experimental Results (Xiaorong Zhang)….....…………..…………………………………….…12

Scaled Up Design (Andy Schultz)……….……………………………..……………………...…14

Process Flow Diagram (Nadezda Mamedova)…….….……………………………...………...…18

Design Comparison (Andy Schultz)...……………….………………………….…………….….20

References……………………….………………………………………………………………..21

Appendices………………….…….….……………………………………………………….......22

Appendix I: Data Tables (Eric Henderson)..………………………………….…….…...22

Appendix II: Results Calculations (Eric Henderson)………… …………………………27

Appendix III: Error Calculations (Nadezda Mamedova)……………..………………… 31

Appendix IV: Scaled Up Design Calculations (Eric Henderson)…………….………… 34

2

Executive Summary – Nadezda Mamedova

Purpose: The purpose of the experiment was to determine operating conditions of a climbing

film evaporator that can recover triethylene glycol from a stream that contains 30 wt%

triethylene glycol. The desired concentration of the exit stream is at 88 wt% triethylene glycol. It

is required that 90,000 gallons of inlet liquid be processed per day.

How information was obtained: Our engineers had four laboratory days to operate a climbing film

evaporator over a range of vacuum pressures to determine which pressure was the most cost

efficient as well as which operating conditions could process the required inlet flow.

Key findings: We determined that in order to be cost efficient and handle the required inlet flow,

we require two climbing film evaporators operated at 20 inHg vacuum. The total cost of installation

and operation for a year is $2,718,483.00. The most expensive requirement is 2.8*107 kg of steam

per year.

Disclaimers and Recommendations: This experiment was performed under the assumption that the

vacuum and system pressures were in equilibrium. We used this assumption to calculate a goal

temperature at which the desired exit composition would be reached. We recommend testing the

exit product composition to determine the accuracy of this assumption. Due to time constraints,

our data gathered was not all started at the same temperature. If more time is allowed, we

recommend running the experiment from the same temperature and atmospheric pressure to allow

for better comparisons.

3

Introduction – Nadezda Mamedova

Our engineers are expanding our company by adding in a climbing film evaporator that can

remove water from a stream of triethylene glycol and recycle the glycol back into a previous

process. The entering stream is at a concentration of 70 wt. % water, and our goal is to have an

outlet stream of no more than 12 wt. % water. The process requires ninety thousand gallons of

mixture to be processed per day.

Climbing film evaporators, also known as rising film or vertical long tube evaporators, are used

in industry for effluent treatment, polymer production, food production, pharmaceuticals, and

solvent recovery.1 The liquid being evaporated is fed from the bottom into long tubes and is

heated with steam condensing on the outside of the tubes, bringing the liquid inside to a boil. The

produced vapors press the liquid against the walls of the tubes. The vapor has a higher velocity

which forces the liquid against the tube wall to rise. This gives the process its name.2

4

Theory – Nadezda Mamedova

A variety of evaporators are used in industry. Our engineers will focus on the climbing film

evaporator operated in batch mode. The evaporator will also be operated under vacuum. The

benefit of this is that it allows for operation at lower temperatures. The mixture of triethylene

glycol and water enter the bottom of a thin wall glass calandria tubes wherein the mixture is

heated to boiling. The water vapor carrying the triethylene glycol climbs the evaporator and

enters a cyclone separator. Here the triethylene glycol condenses and is returned to the

evaporator while the water is collected separately.

Bourgois and LeMaguer found that the dimensionless volumetric vapor flux may be used to

determine the most efficient point of operation. The dimensionless vapor flux, , is given by

[1]

Where:

= vapor density

= liquid density

= gravitational constant

= inside diameter of the tube

Operation efficiency increases with increasing until = 2.5. At this point steam

consumption is at a minimum and the steam temperature and vacuum pressure are optimal.

When the value of is greater than 2.5 the steam consumption needed to produce product at a

given concentration greatly increases as increases, and the process becomes inefficient.

To account for economic efficiency we considered a scale up factor, R. R was determined from

the amount of liquid needing to be processed and the amount our pilot equipment could process.

5

[2]

Where:

R = Scale up factor

Qrequired = Amount of liquid required for processing (90,000 Gallons)

QExperimental = Amount of liquid our laboratory could process

This R factor was carried out to determine other scaled up calculations and cost of the process.

6

Design Plan – Eric Henderson

During the operation of a climbing film apparatus, the continued use of steam becomes very

expensive; therefore, an attempt to minimize this use of steam will be made. A system

temperature at a given pressure will be related to steam flow rate to produce a 88% triethylene

glycol separation using figures from the DOW Chemical Triethylene Glycol manual (figure

below).4 This system temperature will be found by utilizing the Antoine equation in Excel’s

Solver. The Antoine constants are obtained by interpolation of 80% and 90% values in Figure 5

in this lab’s manual (Vapor Pressures of Aqueous Triethylene Glycol Solutions at Various

Temperatures) to produce constants for 88% triethylene glycol separation.

Using these experimental data (triethylene glycol flow, column pressure, steam temperature,

dehydrated triethylene glycol temperature, and condensed water volume), various relationships

between data can be calculated to estimate process cost. For example, once a strong relationship

between triethylene glycol separation, temperature, and pressure has been established, a steam

cost comparison ($/kg) will be analyzed by using data from Table 8.4 (Costs of Some Common

Chemicals).5

By taking the costs into consideration, the optimum steam flow rate will be related to vapor flux

(Equation 1) and feed flow rate to determine the economically optimum scale up plant size.

Equipment sizes will be predicted from using Figure 2, with the notion that the production

Figure 1: Vapor Pressures of Aqueous Triethylene Glycol Solutions at Various Temperatures4

7

requirement of 90k gal/day of process mixture must be met. Analysis of these costs will also

require a raw materials cost estimation from Table 8.3, and ultimately, the total costs

examination by Table 8.2.5

It must be assumed that calculated values for this experiment can be applied to any apparatus

location. That is to say, values such as correction factors for various geological locations do not

need to be used. Furthermore, an accurate exemplification for the current market value costs can

be assumed to be corrected under evaluation techniques from present worth calculations.

Although correction factors are assumed to not apply, scale up factors must still be calculated

once the optimal steam pressure and vacuum pressure are found. The scale up factor calculated

from Equation 2 (from Theory) will be used when sizing the equipment and total steam

consumption from the pilot plant to the commercial plant. On the other hand, the size of the

tubes in the evaporator does not need to be scaled up since the heat transfer will not change.

However, an increased number of tubes in the evaporator would be optimal for the commercial

process.

The optimal steam pressure and vacuum pressure are found by experimental trials in which the

desired composition is achieved by the lowest steam consumption under a constant vacuum

pressure. These values will be used in the cost analysis, along with the amount of cooling water

in the condenser. The amount of cooling water in the condenser is found from the heat necessary

to condense the vapor from the cyclone separator.

Figure 2: Purchased Costs for Evaporators and Vaporizers5

8

Experimental Plan – Andrew Schultz

In this experiment, the group will analyze the separation of water from triethylene glycol (TEG)

via steam evaporation in a column. Several variables will be manipulated throughout the

experiment to evaluate the optimal conditions which yield the best separation of the two

substances. Variables of importance include: steam flow, saturated triethylene glycol flow,

column pressure, steam temperature, dehydrated triethylene glycol temperature, and condensed

water volume. The operating parameters for each are given below in Table 1.

VARIABLE OPERATING RANGE UNITS

Steam Flow Rate 0 – 90 mL/min

Saturated TEG Flow Rate 0 – 90 mL/min

Vacuum Pressure 0 – 30 psi

Throughout the experiment, the independent variables which the group will manipulate include

steam flow, saturated triethylene glycol mix flow, and vacuum pressure. The group will

determine the flow rates for the steam and saturated TEG. These flow rates will be measured by

rotameters located on the operating panel and will remain constant throughout the experiment.

The group will manipulate the pressure inside the column via a vacuum pump. The separation of

water and TEG will then be evaluated at various vacuum pressures.

As the pressure inside the column is manipulated, each new system pressure will be used to

calculate the theoretical (goal) temperature that triethylene glycol must reach to obtain the

desired dehydration. The temperature of the steam flowing into the system is an important

parameter to monitor as it is the initial temperature of the system. The measured (dependent)

goal temperature is the final temperature of the system at a given vacuum pressure. The volume

of condensed water is also an important dependent variable that the group will measure. The

volume of water collected over a period of time as determined by the group will indicate the

effectiveness of separation at a given vacuum pressure.

Table 1: Operating ranges of independent experimental variables.

9

The group will conduct the experiment over the next three laboratory periods according to Table

2 below. The order of evaluation for each vacuum pressure will be cycled during each laboratory

period to evaluate the effect of the temperature of the column being higher than ambient

conditions after the first experiment of each day. This will allow the group to identify and

evaluate the differences, if any, of starting an experiment at ambient conditions versus a system

at higher than ambient temperatures.

DATE TASK

10/06/2015 Measure condensed water volume for vacuum pressures at 19, 20, 21, 22

psi. Evaluate time taken to achieve goal temperature.

10/13/2016 Measure condensed water volume for vacuum pressures at 20, 21, 22, 19

psi. Evaluate time taken to achieve goal temperature.

10/20/2015 Measure condensed water volume for vacuum pressures at 21, 22, 19, 20

psi. Evaluate time taken to achieve goal temperature.

Due to the limitations of the laboratory, specifically the vacuum pump, the range of vacuum

pressures at which the group was able to conduct the experiment were limited. This may be a

factor when the group determines the optimum operating vacuum pressure to separate water

from triethylene glycol to the desired dehydration set point. You also changed the steam

pressure.

Table 2: Schedule of experiments to be performed on remaining experimental laboratory days.

10

Apparatus – Andrew Schultz

Major equipment available in the laboratory for pilot tests for this experiment include an

evaporator, separator, condenser, batch reactor, vacuum pump, and recycle pump. The water-

triethylene glycol (H20/TEG) mixture is pumped from a storage tank into a shell and tube heat

exchanger. The H20/TEG mixture enters tube side at the bottom of the exchanger while steam

enters shell side at the top. As the steam condense around the tubes, the process fluid inside the

tubes is heated until water begins to vaporize. As the water vaporizes, the TEG is pushed to the

outside of the tubes and up the column, hence the namesake climbing film evaporator.6 The

water vapor and TEG then enter a vertical separator wherein the heavier liquid TEG flows to the

bottom of the separator into a recycle loop while the water vapor flows out of the top of the

separator to the condenser. Inside the column, the water vapor condenses downward into a batch

reactor. The condensed water is collected and measured via an outlet stream from the bottom of

the reactor. This volume is indicative of the efficiency of the system under the operational

vacuum pressure conditions – that is, the more water that is collected, the more water that is

separated from the TEG. Thus, the more efficient the system is at the specified operating

conditions. The vacuum recycle pumps facilitate the movement of the process throughout the

system. Rewrite last sentence to clarify.

Important operating variables for this experiment include the vacuum pressure of the system,

vacuum pump water flow, and steam pressure entering the evaporator. The group actively

manipulated the vacuum pressure throughout the experiment in order to evaluate the efficiency

of water evaporation from a water-triethylene glycol mixture. This procedure was predicated on

the idea that the boiling point of fluids decrease at higher vacuum pressures. In order to create

the vacuum inside the system, a fluid stream was necessary to cycle through the vacuum pump.

A water stream was used for this purpose. The group determined a water flow rate that allowed

the pump to create sufficient suction such that the desired vacuum pressure was reached without

causing cavitation. The water flow rate was measured by a rotameter located on the operating

panel. This flow rate was held constant throughout for each trial throughout the experiment. The

group also controlled the pressure of the steam entering the evaporator. This procedure was

based on the idea that there would be an increase in steam condensation at increased pressure.

This pressure was controlled by ball valve. The group attempted to keep the steam pressure

11

constant. However, due to the nature of the control valve, the actual steam pressure each day of

experimenting fluctuated somewhat.

For the experiment, the H20/TEG mixture is pumped from a storage tank tube side into the

evaporator while steam is allowed to flow shell side into the evaporator. As the steam condenses

around the tubes, the heat is transferred to the H20/TEG mixture by conduction, which causes the

water to evaporate and move the TEG up the evaporator into the separator. At this point, the

liquid TEG flows to the bottom of the separator and is recycled back into the system while the

water vapor flows to the top of the separator into a condenser. As the vapor liquefies in the

condensing column, it is collected in the batch reactor. The condensed water is then measured

and analyzed to evaluate the efficacy of the separation under the specified operating conditions.

Valves 14 and 15 were manipulated for each trial to control the vacuum pressure inside the

system. Steam pressure was operated at pressures of 17, 18, 19, 20, and 21 pounds per square

inch gauge (psig). These vacuum pressure set points were used in conjunction with the Antoine

equation to determine a calculated (goal) temperature for the TEG in the bottom of the separator.

Additionally, the position of valve -- was manipulated to control water flow into the vacuum

pump.

Safety hazards of concern for the experiment include chemical inhalation or contact, equipment

malfunction, injury by broken or shattered glass, and injury by contact with steam. The primary

chemical of concern for this experiment is triethylene glycol, which is slightly hazardous in cases

of inhalation, but is very hazardous in cases of eye contact.7 Disturbances in water and water-

triethylene glycol flow could potentially cause cavitation in the water vacuum and recycle

pumps, respectively. Conversely, an exceedingly high suction (vacuum) pressure set point could

cause the glass batch reactor to shatter and send glass shards airborne. Scalding while measuring

the condensed water from the batch reactor or burns from the steam are possible hazards while

conducting the experiment as well. The group employed various safety measures to avoid and

protect against the above hazards. These measures include wearing appropriate protective

equipment like pants, long sleeve shirts, and closed-toed shoes to protect our skin from glass

shards and safety glasses to protect our eyes from the same as well as TEG vapor. Additionally,

12

gloves were worn when handling the steam valves and measuring the condensed water to protect

against burns and scalding.

13

Experimental Results – Xiaorong Zhang

Our experimental data showed that a vacuum gauge pressure of 20 inches of mercury obtained the

highest efficiency, which achieved a product of at least 88 percent of triethylene glycol by weight.

Highest efficiency was achieve when the process required the least amount of time to reach the

goal temperature, while consuming the least

amount of steam.

Table 3 shows the experimental conditions for

vacuum gauge pressure of 20 inches of

mercury. Other trials were run at similar

barometric pressure, but different vacuum

pressures, which led to different temperature

goals. The goal temperaturesshow an

increasing trend with decreasing vacuum

gauge pressure.

Table 4 shows the data of the pilot run under a vacuum pressure of 20 inches of mercury. Due to

water being removed constantly, the volume of water coming from the green hose consistently

decreased. Because of the same reason, the temperature of outgoing fluid (OF) increased slowly

at a lower temperature and greatly increased at a higher temperature. In addition, the LMTD

(logarithmic mean temperature difference) indicates how much heat is transferred. The larger the

LMTD, the more heat is transferred. The decreasing trend on the LMTD is also in agreement with

0 0 0 - 0 - 154 108 143 116 -

5 660 30 22.0 3.5 6600.0 214 158 211 130 49.95501

10 650 30 21.66667 4 6500 217 165 214 139 45.02182

15 550 30 18.33333 5 5500 221 170 220 141 46.20435

20 330 30 11 6 3300 227 187 226 154 36.66374

Time interval

(min)

Steam Valve Temperatures (F)

Volume (mL) Time (s)Rate

(mL/s)

Pressure

(psi)

Consumptio

n (mL)IS, #13 OF, #15 OS, #12 IF, #1 LMTD

Experiment #3 Conditions

Barometric pressure 29.2 inHg

741.68 mmHg

Vacuum pressure 20 inHg

558.8 mmHg

Antoine pressure 182.88 mmHg

Temperature goal 84.23954 C

183.6312 F

Start height 24 in

End height 18.75 in

Volume process 25.77527 gal

Process time 20 min

Thoroughput 77.32582 gal/hr

Scale-up factor, R 48.49609

Table 3: Experimental conditions at 20inHg.

Table 4: Experimental data for pilot run at 20inHg.

14

the volume of water trend, since less water was evaporated at a higher temperature, which means

less heat was transferred.

Table 5 shows the relation between heat transfer and steam pressure. During the experimental

procedure it was difficult to the keep the apparatus at a constant steam pressure; however,

determining an efficient constant steam pressure is important for the scaled up process. From Table

5, both steam pressures of 3.5 PSI and 4 PSI obtained a higher overall heat transfer coefficient.

Nevertheless, due to a decreasing trend of heat transfer with an increase in temperature, heat

transfer at 4 PSI steam pressure shows a better result that achieves the most heat transfer.

Figure 3 shows the steam consumption for each pilot run under different vacuum gauge pressures.

The consumptions for all of the runs, except for at 18 inches of mercury, are around 30 liters.

However, the pilot run at 20 inches of mercury required less process time, which makes it our most

steam

0

-14300.5 3.5

-14038.1 4

-11792.2 5

-7029.21 6

Pressure

(psi)

Heat Transfer

Overall heat transfer coefficient (kJ/ft2*C)

26.30885753

28.65593543

23.45535483

17.61974656

Heat (kJ)

Table 5: Relationship between heat transfer and steam pressure.

Figure 3: Comparison of total steam consumption (in liters) at various vacuum steam

pressures (in inches of Mercury).

15

desirable run for scale up. For the unexpectedly large steam value for 18 inches of mercury, our

group did not find any apparent reason for this abnormal value.

Propagation of Error

A propagation of error analysis was calculated on throughputs and on the scale-up factor (R).

These two values are the main error sources for the scale up design. The error in the

experimental throughputs is calculated as 46.22±30.88 and R is calculated as 121.34±88.52.

Unfortunately, these errors are large, which affects the scale up design substantially. The cause

of these big errors is that our group had a difficult time measuring the starting and ending height

of the feed tank. Our group will try to figure out a good way to measure the height of the tank

during the make-up experiment for our revised report. Good idea.

Scaled Up Design - Andrew Schultz

The scaled up design was based on the data and experimental results from several pilot trials.

The group utilized Equation 2 to determine the scale up factor (r) that was needed to scale the

experimental conditions and equipment to meet the commercial requirements outlined in Table 6

below.

The scaling factor was then used to scale the throughput as well as triethylene glycol and water

volumetric flow rates. These calculations were based on the plant operating 24 hours per day,

365 days per year and were calculated to meet the dehydration specification of 12 weight percent

water in triethylene glycol. These values are represented below in Table 7.

Table 6: The scale up factor based on the pilot experiments.

Scale Up

Factor (r)

Evaporator SA (ft^2)

Condenser SA (ft^2)

Vacuum Pump (hp)

Cyclone Separator

Area (ft^2)

1.87

1.55

2 96.99

0.44

Pilot Commercial Size

48.50

527.69

21.42

633.23

16

In evaluating the optimal conditions under which the system should be operated to most

efficiently reach the dehydration specification, the group determined that the most costly element

of the experiment was the cost of steam. Therefore, it was decided to hold the steam input

constant at four pounds per square inch while varying the system vacuum pressure. The Antione

Equation was used to calculate the temperature that was necessary to meet the 88 weight percent

triethylene glycol specification for each variation of vacuum pressure. The time required to reach

this temperature as well as the volume of the triethylene and water mixture processed were

recorded and evaluated to determine the optimal operating conditions. These values are outlined

in Table 8 below.

Based on these results, it was determined that the operation of the system was most efficient at a

vacuum pressure of 20 inches of mercury, and this pressure will be used as the basis for the scale

up. At this vacuum pressure, the system has the largest processing rate as well as requiring the

lowest system temperature. This is significant because it is desired to optimize the processing

rate while maintain an economical scale up – that is, process the largest volume of the triethylene

glycol and water mixture at the lowest temperature in order to utilize the least amount of steam

to meet the desired specifications.

90,000 [gal/day]

87,424.62 [gal/day]

329.94 [m^3/day]

2,572.38 [gal/day]

9.71 [m^3/day]

Triethylene Glycol

Water Removed

Required Production

System throughput

Table 7: Scaled system throughput, triethylene glycol,

and water flow rates.

Volume Processed (gal) Processing Time (min) Rate (gal/day)

8.5918 27.5 449.8957

8.5918 25 494.8852

30.6848 27 1636.5252

25.7753 20 1855.8196

1.9638 20 141.3958

Tested System Conditions

Vacuum Pressure (inHg) System Temperature (F)

18 203.9

17 208.0

19

20

21

199.4

183.6

183.6

Table 8: Experimental conditions and results from pilot tests performed at vacuum pressures from 17 to 21

inches of Mercury.

17

Equation 2 was manipulated to scale the major equipment to meet commercial specifications.

The major equipment pieces which are necessary to scale up include the evaporator, cyclone

separator, and condenser. The scaled up values for the major equipment is included in Table 9

below.

The scaled up equipment costs were estimated using the CAPCOST cost analysis program.

Additional costing methods (e.g., cost of labor, raw materials, etc.) and correlations were derived

using Analysis, Synthesis, and Design of Chemical Processes by Turton et al. All correlations

and costing analyses should be consistent between CAPCOST and the textbook since the

program was designed by the authors of the textbook. Furthermore, all correlations are based on

industry averages and do not require the use of corrective factors.

The cost analysis data are depicted in the following tables.

Scale Up

Factor (r)

Evaporator SA (ft^2)

Condenser SA (ft^2)

Vacuum Pump (hp)

Cyclone Separator

Area (ft^2)

1.87

1.55

2 96.99

0.44

Pilot Commercial Size

48.50

527.69

21.42

633.23

Table 9: Scaled up values for major equipment.

Table 10: Total equipment cost outlined by major

pieces of equipment.

Equipment Cost (USD)

Evaporator 374,000$

Cyclone 2,070$

Vacuum Pump 16,970$

Condenser 42,300$

Triethylene Glycol Storage Tank 68,400$

Process Water Storage Sphere 38,400$

Water By Product Storage Tank 87,900$

Total $630,000

Total Equipment Cost

18

Direct costs Basis Cost (USD)

Purchased equipment 630,000$

Equipment installation 47% of equipment cost 296,000$

Instrumentation and controls 36% of equipment cost 227,000$

Piping 68% of equipment cost 428,000$

Electrical systems 11% of equipment cost 69,300$

Buildings 18% of equipment cost 113,000$

Yard improvements 10% of equipment cost 63,000$

Service facilities 70% of equipment cost 441,000$

2,270,000$

Indirect Costs Basis Cost (USD)

Engineering and supervision 33% of equipment cost 208,000$

Construction expenses 41% of equipment cost 258,000$

Legal expenses 4% of equipment cost 25,200$

Contractor's fee 22% of equipment cost 139,000$

Contingency 44% of equipment cost 277,000$

$ 907,000

Capital Investment Costs Basis Cost (USD)

$3,180,000

Working capital 15% of total capital investment 561,000$

$3,740,000

Itemized Capital Investment Cost

Total Indirect Plant Cost

Capcost

Total Direct Plant Cost

Fixed Capital Investment

Total Capital Investment

Raw Materials 883$

Labor 468,000.00$

Util ites 828,000.00$

Maintenance 223,000.00$

Operating Supplies 33,500.00$

Laboratory Charges 70,200.00$

Royalties 115,000.00$

Depreciation 318,000.00$

Taxes 100,000.00$

Insurance -$

Rent -$

Totals 2,156,583.00$ 621,000.00$

2,777,583.00$

EXPENSES

Total annual cost

Total Manufactoring Costs General Expenses

Distribution & marketing 351,000.00$

Research & development 159,000.00$

Administrative Costs 111,000.00$

Table 11: Outline of total annual costs (TAC).

Table 12: Outline of costs for total capital investment.

19

Process Flow

Diagram -

Nadezda

Mamedova

20

Propagation of Error Analysis – Eric Henderson

Propagation of error analysis sample hand calculations for the following table can be found in

Appendix III.

Piece of Equipment Error in Size

σQ_Experimental ±6.29*10-3 gal/hr

σR ±0.0125

σTubes ±0.296

σCyclone separator area ±0.2 ft2

σPump air flow ±0.433 CFM

Overall, our error in equipment size yielded a very small standard deviation; therefore, our scale

up calculations are confirmed to be precise. Our average experimental error was found to be less

than five percent for all data in question. Consequently, our data are confirmed to be statistically

significant.

Design Limitations, Assumptions, and Recommendations - Nadezda Mamedova

This experiment was performed under the assumption that the vacuum and system pressures

were in equilibrium. We used this assumption to calculate a goal temperature at which the

desired exit composition would be reached. We recommend testing the exit product composition

to determine the accuracy of this assumption.

Due to time constraints, our data gathered were not all started at the same temperature. If more

time is allowed, we recommend running the experiment from the same temperature and

atmospheric pressure to allow for better comparisons.

The largest limitation to our experiment was the start and end height of the liquid level in ….,

which we used to calculate the amount of liquid processed. Errors in the amount of liquid processed

would carry through all the calculations and cost analysis.

Table 13. Error of Equipment Sizing

21

Comparison with Design Based On Literature Values – Andrew Schultz

An experiment was conducted using an industrial climbing film evaporator to concentrate

pineapple juice for widespread commercial purposes. In Bourgois and LeMaguer’s experiment,

the evaporator had three sections, each being similar in length (2.13 meters) with differing

quantities of tubes – 66, 111, and 156. In total their system had a processing capacity of over

5,000 kilograms per hour or 120,000 kilograms per day. For our purposes, we are processing an

inlet feed of 90,000 gallons per day, so both systems are analogous in total processing

capabilities per day. Further, the overall heat transfer coefficient for our triethylene glycol

system was calculated to 26.31 kilojoules per square foot per degree Celcius or 283 Watts per

square meter per Kelvin, which is dissimilar to the calculated range Bourgois and LeMaguer

determined for their industry pineapple juice application (1,000 to 1,600 Watts per square meter

per Kelvin). This source of error do you mean differences or errors or both? could derive from

the measured tank height, compositional differences between triethylene glycol and pineapple

juice, the dehydration versus concentration processes not being directly comparable, as well as

improved present-day equipment compared to the equipment Bourgois and LeMaguer had

available.

22

Report Grade: 87/100

References

1. Aschner, F.S. & Schaal, M. & Hasson, D. (1971). “Large Long-Tube Evaporators for

Seawater Distillation”.

2. “Evaporation Handbook”, 4th edition, An Invensys Company, APV Americas, Engineered

Systems Separation Technologies. [1] Last Accessed on 4 October 2015

3. Bourgois, J., & LeMaguer, M. (1984). Modelling of Heat Transfer in a Climbing-Film

Evaporator: Application to an Industrial Evaporator. Journal of Food Engineering , 39-50.

4. Triethylene Glycol Manual (n.d.): n. pag. DOW Chemical, Feb. 2007.

5. Turton, Richard. Analysis, Synthesis, and Design of Chemical Processes. Upper Saddle River:

Prentice Hall, 2014. Print.

6. “Evaporation Handbook”, 4th edition, An Invensys Company, APV Americas, Engineered

Systems Separation Technologies. [1] Last Accessed on 4 October 2015

7. "Triethylene Glycol MSDS." Material Safety Data Sheet (MSDS). Science Lab, 21 May 2013.

Web. 6 Oct. 2015. .

23

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Scale-u

p facto

r, R636.5112

00

0-

0-

158111

146102

--

5690

3023.0

3.56900.0

215157

212131

51.08323-427.522

10660

3022

56600

218162

215136

49.064-14238.6

15560

3018.66667

55600

223165

221138

51.97715-11998.1

20280

309.333333

62800

228188

228151

38.71716-5948.89

Time interval

(min)

Steam

Valve Tem

peratures (F)H

eat Transfer

Volum

e (mL)

Time (s)

Rate

(mL/s)

Pressure

(psi)

Consumptio

n (mL)

Overall heat transfer coefficient (kJ/ft 2*C)

0.769148332

26.67067476

21.21437074

14.12089424

IS, #13O

F, #15O

S, #12IF, #1

LMTD

Heat (kJ)

-

Appendix I: Data Tables –

Eric Henderson

Vacuum Pressure = 21 inHg

Co

mm

ercial P

roce

ss

Evap

ora

tor

Surface

area

6925.902ft

2

Nu

mb

er o

f tub

es

4456

Cyclo

ne

Vo

lum

e337.3509

ft3

Cro

ss-sectio

nal are

a281.202

ft2

Diam

ete

r18.92188

ft

Co

nd

enser

Total su

rface are

a8311.082

ft2

Nu

mb

er o

f tub

es

4456

Va

ccum

pu

mp

Mo

tor

75H

P

24

Expe

rime

nt #3 C

on

ditio

ns

Baro

me

tric pre

ssure

29.2in

Hg

741.68m

mH

g

Vacu

um

pre

ssure

20in

Hg

508m

mH

g

An

toin

e p

ressu

re233.68

mm

Hg

Tem

pe

rature

goal

84.23972C

183.6315F

Start he

ight

24in

End

he

ight

18.75in

Vo

lum

e p

roce

ss25.77527

gal

Pro

cess tim

e20

min

Tho

rou

ghp

ut

77.32582gal/h

r

Scale-u

p facto

r, R48.49609

Co

mm

ercial P

roce

ss

Evap

ora

tor

Surface

area

527.6878ft

2

Nu

mb

er o

f tub

es

339

Cyclo

ne

Vo

lum

e25.70293

ft3

Cro

ss-sectio

nal are

a21.42492

ft2

Diam

ete

r5.222935

ft

Co

nd

enser

Total su

rface are

a633.2253

ft2

Nu

mb

er o

f tub

es

339

Va

ccum

pu

mp

Mo

tor

75H

P

00

0-

0-

154108

143116

--

5660

3022.0

3.56600.0

214158

211130

49.95501-14300.5

10650

3021.66667

46500

217165

214139

45.02182-14038.1

15550

3018.33333

55500

221170

220141

46.20435-11792.2

20330

3011

63300

227187

226154

36.66374-7029.21

Time interval

(min)

Steam

Valve Temperatures (F)

Heat Transfer

Volume (m

L)Tim

e (s)Rate

(mL/s)

Pressure

(psi)

Consumptio

n (mL)

Overall heat transfer coefficient (kJ/ft 2*C)

26.30885753

28.65593543

23.45535483

17.61974656

IS, #13O

F, #15O

S, #12IF, #1

LMTD

Heat (kJ)

-

Vacuum Pressure

= 20 inHg

25

Expe

rime

nt #3 C

on

ditio

ns

Baro

me

tric pre

ssure

29.15in

Hg

740.41m

mH

g

Vacu

um

pre

ssure

19in

Hg

482.6m

mH

g

An

toin

e p

ressu

re257.81

mm

Hg

Tem

pe

rature

goal

93.00908C

199.4164F

Start he

ight

22.75in

End

he

ight

16.5in

Vo

lum

e p

roce

ss30.68485

gal

Pro

cess tim

e27

min

Tho

rou

ghp

ut

68.18855gal/h

r

Scale-u

p facto

r, R54.99457

Co

mm

ercial P

roce

ss

Evap

ora

tor

Surface

area

598.3979ft

2

Nu

mb

er o

f tub

es

385

Cyclo

ne

Vo

lum

e29.14712

ft3

Cro

ss-sectio

nal are

a24.29586

ft2

Diam

ete

r5.561874

ft

Co

nd

enser

Total su

rface are

a718.0775

ft2

Nu

mb

er o

f tub

es

385

Va

ccum

pu

mp

Mo

tor

75H

P

00

0-

0-

7367

6970

--

5610

3020.3

36100.0

215158

141118

19.68543-1372.7

10590

3019.66667

35900

213159

177136

29.42424-13420.5

15630

3021

4.56300

220171

217140

44.17116-13561.9

20490

3016.33333

64900

223177

220147

40.68681-10513.8

25310

3010.33333

63100

226189

225153

34.79465-6610.62

27200

306.666667

6.5800

228199

227162

26.82683-1702.39

5.832023354

Ove

rall he

at transfe

r coe

fficien

t (kJ/ft2*C

)

6.408581699

41.91723654

28.21704308

23.74842634

17.46059779

IS, #13O

F, #15O

S, #12IF, #1

LMTD

He

at (kJ)

-

Time

inte

rval

(min

)

Steam

V

alve Te

mp

eratu

res (F)

He

at Transfe

r

Vo

lum

e (m

L)Tim

e (s)

Rate

(mL/s)

Pre

ssure

(psi)

Co

nsu

mp

tio

n (m

L)

Vacuum Pressure

= 19 inHg

26

Expe

rime

nt #3 C

on

ditio

ns

Baro

me

tric pre

ssure

29.15in

Hg

740.41m

mH

g

Vacu

um

pre

ssure

18in

Hg

457.2m

mH

g

An

toin

e p

ressu

re283.21

mm

Hg

Tem

pe

rature

goal

95.49561C

203.8921F

Start he

ight

24.5in

End

he

ight

22.75in

Vo

lum

e p

roce

ss8.591758

gal

Pro

cess tim

e25

min

Tho

rou

ghp

ut

20.62022gal/h

r

Scale-u

p facto

r, R181.8603

Co

mm

ercial P

roce

ss

Evap

ora

tor

Surface

area

1978.829ft

2

Nu

mb

er o

f tub

es

1273

Cyclo

ne

Vo

lum

e96.38598

ft3

Cro

ss-sectio

nal are

a80.34344

ft2

Diam

ete

r10.11417

ft

Co

nd

enser

Total su

rface are

a2374.595

ft2

Nu

mb

er o

f tub

es

1273

Va

ccum

pu

mp

Mo

tor

75H

P

00

0-

0-

158111

14288

--

5640

3021.3

36400.0

214165

210138

41.98642-626.223

10660

3022

4.56600

219169

215142

42.99861-14244

15550

3018.33333

55500

222173

219144

43.30272-11814

20370

3012.33333

63700

226185

224152

37.27519-7901.47

25160

305.333333

6.51600

228204

228168

21.51106-3399.42

Time interval

(min)

Steam

Valve Tem

peratures (F)

14.52355414

IS, #13O

F, #15O

S, #12IF, #1

LMTD

Heat (kJ)

Overall heat transfer coefficient (kJ/ft 2*C)

1.370724421

30.44439011

25.07338866

19.48128697

-

Heat Transfer

Volum

e (mL)

Time (s)

Rate

(mL/s)

Pressure

(psi)

Consumptio

n (mL)

Vacuum Pressure

= 18 inHg

27

00

0-

0-

73112

127110

--

5660

3022.0

46600.0

218170

215142

41.85132256.1066

10600

3020

4.56000

220174

217145

40.25473-12916.1

15490

3016.33333

54900

222178

219150

37.78804-10525.2

20380

3012.66667

63800

226185

224154

36.43561-8115.02

25180

306

6.51800

228200

227166

24.60221-3829.99

27.5110

303.666667

6.5550

229208

228171

18.27526-1169.09

5.879166933

Overall heat transfer coefficient (kJ/ft 2*C)

0.562394864

29.48791609

25.59806608

20.46884367

14.30714947

IS, #13O

F, #15O

S, #12IF, #1

LMTD

Heat (kJ)

-

Time interval

(min)

Steam

Valve Temperatures (F)

Heat Transfer

Volume (m

L)Tim

e (s)Rate

(mL/s)

Pressure

(psi)

Consumptio

n (mL)

Expe

rime

nt #3 C

on

ditio

ns

Baro

me

tric pre

ssure

29.15in

Hg

740.41m

mH

g

Vacu

um

pre

ssure

17in

Hg

431.8m

mH

g

An

toin

e p

ressu

re308.61

mm

Hg

Tem

pe

rature

goal

97.80153C

208.0428F

Start he

ight

24in

End

he

ight

22.25in

Vo

lum

e p

roce

ss8.591758

gal

Pro

cess tim

e27.5

min

Tho

rou

ghp

ut

18.74565gal/h

r

Scale-u

p facto

r, R200.0464

Co

mm

ercial P

roce

ss

Evap

ora

tor

Surface

area

2176.712ft

2

Nu

mb

er o

f tub

es

1400

Cyclo

ne

Vo

lum

e106.0246

ft3

Cro

ss-sectio

nal are

a88.37778

ft2

Diam

ete

r10.60783

ft

Co

nd

enser

Total su

rface are

a2612.054

ft2

Nu

mb

er o

f tub

es

1400

Va

ccum

pu

mp

Mo

tor

75H

P

Vacuum Pressure

= 17 inHg

28

Appendix II: Results Calculations - Eric Henderson

29

30

31

32

Appendix III: Error Calculations – Nadya Mamedova

33

34

35

Appendix IV: Scale Up Calculations – Eric Henderson

36

37

38

39