ADAMSON UNIVERSITY

COLLEGE OF ENGINEERING

CHEMICAL ENGINEERING DEPARTMENT

Chemical Engineering Laboratory 1

Experiment No. 6

PLATE AND FRAME FILTRATION

Submitted by:

Group 1

Arnuco, Arjay

Baligod, Jeffrey

Cruz, Nichole

Martin, Jeanell

Penalba, Benjie

Submitted to:

Engr. Albert Evangelista

August 11, 2015

TRANSMITTAL LETTER

August 6, 2015

Engr. Albert EvangelistaChemical Engineering DepartmentAdamson UniversityErmita, Manila

Engr. Evangelista:

In compliance with the fulfillment of the requirements on the subject “Unit Operations Lab

1”, the group would like to present this experiment report entitled “PLATE AND FRAME

FILTRATION” in accordance with your instructions. The main purpose of this experiment

report is to determine the optimum filtration time and cake thickness as well as filtration

pressure as a function of particle size. We hope that this experiment report will meet you

approval.

Respectfully Yours,

Group 5

Bernales, Candice

Gonzalgo, Leera

Lorenzo, Jan Zedric

Mata, Arriane Jay

Mercado, Roger Jayson

Abstract

The plate and frame filter press are equipment used to separate solids from the liquids of

a slurry mixtures. The group was able to identify the basic parts of the filter press and gain

experience in the operation of the equipment. The solid products remained from the filtration

technique are called the filter cake. The group used Kaolin suspended in water then filtered

throughout the experiment. To determine the relationships with filtration time, volume and

pressure, thickness of the filter cake was used. The results showed that if filtration rate is

lowered, the thickness of the cake increases. Thickness of the cake also showed direct

proportionality with time as the filtration progress.

I. OBJECTIVES

1. To be able to identify the basic parts and functions of a plate and frame filter

press.

2. To gain experience in the operation and maintenance of a plate and frame filter

press

3. To determine the optimum filtration time and cake thickness.

4. To determine the optimum filtration pressure as a function of particle size.

5. To develop ability to diagnose possible defects in a filter press design

6. To determine the washing characteristics of particular cakes.

7. To determine capacity of the filter press.

8. To be able to design a large scale plate and frame filter press based on the data

obtained.

9. To estimate operation cost of separating the solids from liquid using filter press.

II. Materials/Equipment Needed

1. Equipment

- 1 unit laboratory plate and frame filter press

2. Glass wares

- 1 pc. Graduated Cylinder, 1000 ml capacity

- 1 pc. Stirring rod, glass

- 2 pc. Beaker, 1000 ml capacity

- 1 pc timer

- 1 pc screen, mesh 60

3. Filtering Materials

- 30L Calcium Oxide Solution, 10% Concentration

- 30L clay-water suspension

- 30 L Kaolin-Water Suspension

III. Equipment Set Up

IV. Theory

Filtration is the operation carried to separate solid materials from a liquid by forcing the slurry through a porous medium that retains the solid. The solids are removed the liquid and remain on the porous filtering medium as a cake.Different types of filtration equipment and operational methods have been developed and conceived based on practical experience. The current filtration theory is based largely on experimental data, and most calculation requires experimental information on the particular slurry (or solid-liquid mixture) involved.To push a mixture of solids and liquids into the filtering unit and through the resistance offered by the cake and filtering medium , a driving force is required and could be obtained by pressure on the entering side of the unit by vacuum on the liquid exit end. Certain types of filters obtain the required pressure by use of a liquid head so that gravity forces the liquid through the filtering medium while other types employ positive or vacuum pumps to supply the necessary driving force.The filtering medium requires strong fiber. When the average size of the solid particles in the slurry is smaller than the average opening between the fibers making

up the cloth, a true filtering medium isa required. The filter aid is extremely important at the beginning of filtration.Different types of filter are available in the market like gravity filters, plate and frame filters. The plate and frame filter press consists of a series of plates arranged alternately with separating frames. Each side of the plates is covered with a cloth, and the whole assembly is held together by mechanical force.The frames separating the plates from a hollow space into columns. The slurry is forced. The liquid passes through the filter cloth on the plate and from there to a dust, which carries the filtrate (i.e. the filtered liquid) amount in the unit. When the space in the frames becomes filled with cake, the filtrates must be stopped and the cake must be removed. The operation must be batch wise, and considerable time and labor are required for the cleaning operations.The plate and frames are constructed of metal, wood, or rubber, and the pumps are required to supply the pressure for forcing the slurry into and through the unit. The plate and frame filter presses are generally used only when the value of the cake is high and the quantity of the cake is relatively small.

V. Procedure

A. Preparation of Raw Materials

1. Pulverize the raw material in a ball mill and pass it through a 60-mesh screen.

2. Prepare a 10% wt. slurry of clay and water.

3. Stir well to dissolve disperse particles and to homogenize the slurry.

B. Preparation of the Filter Press

1. Put the slurry into the feed tank. Stir to homogenize and to prevent settling of the

clay.

2. Pump the clay slurry into the filter press.

3. Record the feed inlet pressure.

4. Collect the filtrate for a specific time ranges and determine the volume.

5. After the filtration period, dismantle the plate and wash off the particles with

water. After the parts have dried, assemble them back into the filter press.

VI. Results and Discussion

Plot the data for the filtrate volume vs. filtration time. Explain the reduction of filtration volume with respect to the filtration time.

20 40 60 80 100 120 140 160 180 200 300 400 500 750 10000

0.5

1

1.5

2

2.5

3

3.5

Filtration Volume vs Filtration Time

Filtration Volume (liters)

As shown in above figure, the filtration volume gradually decreases as the filtration time increases. This can be explained by the increasing thickness of the cake. As the cake thickens, the filtrate would have difficulty to pass through the plates. And since the thickness of the cake increases as the time increases, the filtration volume will decrease as the time increases.

Plot the data for the cake thickness vs. filtration time. How does the cake thickness vary with time? Why?

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10

Cake Thickness vs Filtration Time

Cake Thickness (mm)

As shown in the above figure, the cake thickness gradually increases as the filtration time increases. This is because as the mixture pass through the plates the cake will be left and the filtrate will be removed. As time goes by, large amount of the mixture have passed through the filter cloth that is why the thickness of the cake increases.

Plot the data for the filtration pressure vs. filtration time. What is the relationship between filtration pressures with regards to the filtration time? Why?

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1

2

3

4

5

6

7

Filtration Pressure vs Filtration Time

Filtration Pressure (psig)

As shown in the figure above, the filtration pressure increased as the filtration time increased. This can be explained by the cake thickness. The cake formed becomes thick as time goes by, the mixture will be having difficulty to pass through the plates therefore more pressure is needed to be exerted. Since the cake thickness increases as time increases, the pressure will also increase.

Calculate the capacity of the filter press (i.e. the full capacity of the plates).

Capacity= 12L

1000 s x1hr

3600 sx

1day24 hrs

=1036.8Lday

Determine the typical moisture content of the cakes.

Initial weight of cake = 0.052 gDry weight of cake = 0.028 g

%Moisture=0.052−0.0280.052

x100=46.15 %

VII. Conlusions

The following are concluded based on the data gathered from this experiment:

It is therefore concluded that filtration volume is inversely proportional to the filtration since the filtration volume collected decreases as the filtration time increases.

It is therefore concluded that cake thickness is directly proportional to the filtration time since the cake thickness measured increases as the filtration time increases.

It is therefore concluded that filtration pressure is directly proportion to the filtration time since the filtration pressure increased when the filtration time is increasing.

VIII. References

http://www.pharmainfo.net/book/pharmaceutical-machines/plate-and-filter-

press

https://ertelalsop.com/depth-filtration-equipment/plate-and-frame-filter/

http://www.andritz.com/products-and-services/pf-detail.htm?productid=5439