Lab Report Plate and Filter Press

PLATE AND FRAME FILTER PRESS

1.0 OBJECTIVES

1. To be able to identify the basic parts and function of a plate and frame filter press. 2. To determine the optimum filtration time and optimum cake thickness 3. To develop the operation and maintenance of a plate and frame filter press 4. To identify the variation in time of filtrate quantity and solid concentration in filtrate 5. To study the mass of filter cake dependent on filtrate quantity

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2.0 SUMMARY The purpose of Plate and Frame Filter Press experiments is to study the operation of filter press for filtration of calcium carbonate slurry and to determine filter medium resistance and specific cake resistance from filtration data obtained. The experiment was started by weighing 5kg of calcium carbonate powder, then it being dissolved in 100 L of water in a container and transfers it to the slurry tank. Once the pump being switch on, the RUN light will light green, this indicates that the process of feeding the slurry into the filter press has started. Time taken for every 5 L of collected filtrate volume, V were recorded until there were no filtrate comes out. The weight of wet cake and dry cake has been weight and recorded. The result are, time/Volume, t/V for the volume of filtrate reach the 5L is18.6s/V and 10L of filtrate, is 15.12 s/L. The t/V different between them is the 3.84 s/V. The time taken increase and t/V decrease when the collected filtrate volume increase. Theoretically, the filter plates are grooved and covered over with filter cloths. The filtrate passes through the filter cloth and flows via the grooves in the plates into a collecting pipe. The filtrate exits the plate and frame filter press through the collecting pipe and is collected in the filtrate tank. The solid material is separated off at the filter cloth, where it forms a growing filter cake. As the filter cake becomes thicker, its flow resistance also increases. The weight of wet cake for Tray 1 is 1.66kg, for Tray 2 is 1.02 kg and Tray 3 is 0.86 kg and the weight of dry cake for Tray 1 is 1.98kg, for Tray 2 is 1.34kg and for Tray 3 is 1.18kg. From the data, the weight ratio of wet cake to dry cake (mF/ mc) is 0.787, the density of calcium carbonate (ρ) is 2.93 g/cm3 and the total active filter area is 2. 209m2. Graphs of t/V versus V were plotted. The values of filter medium resistance (Rm) and cake resistance (α). From the calculation, the Filter medium resistance, Rm for Tray 1 is 7.3583x1010 m-1, Tray 2 is 4.7093x1010 m-1, and for Tray 3 is 4.7093x1010 m-1. For cake resistance,α the value for Tray 1 is 10356214.76 m4/kg, for Tray 2 is 6627977.45 m4/kg and for Tray 3 is 6627977.45 m4/kg.

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3.0 RESULTS Weight fraction of calcium carbonate in slurry = 5 wt% Weight of wet cake, Tray 1 = 1.66 kg Tray 2 = 1.02 kg Tray 3 = 0.86 kg Weight of dry cake, Tray 1 = 1.98 kg Tray 2 = 1.34 kg Tray 3 = 1.18 kg Weight ratio of wet cake to dry cake (mF/ mc) = 0.787 Density of calcium carbonate (ρ) = 2.93 g/cm3 Total active filter area = 0.47 m x 4.7 m = 2.209 m2 Pressure drop = 50 Psi 50 Psi x

1 atm 14.696 Psi

x

101.325 kPa 1 atm

= 344.74 kPa

Total filtration time = 1084.2 s Total volume of filtrate = 105 L

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Filtrate volume, V (L)

Time, t (s)

Time /Volume, t/V (s/ L)

0

0

undefined

5

93

18.6000

10

151.2

15.1200

15

206.4

13.7600

20

261

13.0500

25

318

12.7200

30

371.4

12.3800

35

426.6

12.1886

40

483

12.0750

45

511.8

11.3733

50

567.6

11.3520

55

621.6

11.3018

60

676.2

11.2700

65

730.8

11.2431

70

782.4

11.1771

75

795.6

10.6080

80

807.6

10.0950

85

859.2

10.1082

90

913.8

10.1533

95

968.4

10.1937

100

1023.6

10.2360

105

1084.2

10.3257

Table 1: Table of data of experimental results obtained. Based on the results obtained, a graph of t/ V against V is plotted. From the graph, the equation of the line is y = 0.0197x + 12.368. The slope of the line and y-intercept obtained are as follows, Slope of the line = - 0.0197x y- intercept = 12.368 4|Page

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t/V (s/L) vs V (L) 20 18

16

y = -0.0197x + 12.368

t/V (s/L)

14 12 10 8 6 4 2 0 0

20

40

60

80

100

120

V (L)

Figure 1: Graph of t/ V (s/ L) against V (L). The slope of the line represents the value of intercept represents the value of

1 qo

Kc 2

in seconds per litre (s/ L) while the y-

.

Tray

10 L

50 L

70 L

Viscosity, µ (Pa.s)

0.0128

0.02

0.02

Density, ρ (g/cm3)

0.995

0.997

1.001

Table 2: Table of data for viscosity and density for each tray

Tray Filter medium resistance, Rm (m-1) Cake resistance, α (m4/kg)

1

2

3

- 7.3583x1010

- 4.7093x1010

- 4.7093x1010

10356214.76

6627977.45

6627977.45

Table 3: Values of filter medium resistance (Rm) and cake resistance (α)

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4.0 DISCUSSION

Filtration defines as a process of separation of solids from a fluid by passing the same through a porous medium that retains the solids but allows the fluid to pass through (Rita Kudarha, 2014). Generally, filtration is the process of separating suspended solid matter from a liquid, by causing the latter to pass through the pores of some substance called a filter. The liquid which has passed through the filter is called the filtrate. The filter may be paper, cloth, cotton-wool, asbestos, slag- or glass-wool, unglazed earthenware, sand, or other porous material. Plate and frame filter presses are used in the beverage industry, for example, to clarify intermediate products. For industrial filtration, it can be range from the simple straining to highly complex separation and the solid content of the feed ranges from a trace to a very high percentage. Many industrial filters are pressure filters, vacuum filters or centrifugal separators. A discontinuous Pressure Filters such as Plate and Frame Filter Press apply large differential pressure across septum to give economically rapid filtration with viscous liquids or fine solids (Sjykmuch, 2013). A part from that, filters are divided into three types which are cakes filters, clarifying filters and cross flow filters. Next, a cake filters separate relatively large amounts of solids as a cake of crystal or sludge.

The purpose of Plate and Frame Filter Press experiments is to study the operation of filter press for filtration of calcium carbonate slurry and to determine filter medium resistance and specific cake resistance from filtration data obtained. This experiment is started by weighing 5kg of calcium carbonate powder (commercial grade) and dissolved it with the 100 L of water in a container and transfers it to the slurry tank. After open the air regular outlet valve and check the pressure gauge setting, the hydraulic pump air valve need to be release. Then, pack the filter press by pushing it toward the stationary platen and move the moving platen towards the filter plate pack. Next, the hydraulic ram needs to be pump until it reaches the required working pressure. Once the ON button at the control panel is pressed and the RUN light will light, this indicates that the process of feeding the slurry into the filter press has started.

During the experiment, the time taken for every 5 L of collected filtrate volume, V need to recorded until there are no filtrate comes out from the equipment. After that, the weight of wet cake and dry cake has been weighing and record. In theoretically, the filter 6|Page

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plates are grooved and covered over with filter cloths. The filtrate passes through the filter cloth and flows via the grooves in the plates into a collecting pipe. The filtrate exits the plate and frame filter press through the collecting pipe and is collected in the filtrate tank. The solid material is separated off at the filter cloth, where it forms a growing filter cake. As the filter cake becomes thicker, its flow resistance also increases (Juphil Lamanilao, 2010).

From the recorded data in Table 1, the time taken, t to volume of filtrate reach the 5L is 93s and the time/Volume, t/V is 18.6s/V. For 10L of filtrate, the time taken is 151.2 s and the t/V is 15.12 s/L. The t/V different between them is the 3.84 s/V. From that, it can be concluded that the time taken increase and t/V decrease when the collected filtrate volume increase. The t/V for filtrate volume starts to decrease slowly not likely the beginning the experiment. The t/V is decrease until the calcium carbonate slurry, CaCO3 is fully used. When the filtrate that come out from the equipment is getting slow, it indicate the volume of filtrate is getting low. Lastly, the total volume of filtrate is 105L and total filtration time is 1084.2 s and the t/V value is 10.3257 s/V. In this plate and filter press experiment, the weight fraction of calcium carbonate in slurry is 5 wt%. From the results obtained, the weight of wet cake for Tray 1 is 1.66kg, for Tray 2 is 1.02 kg and Tray 3 is 0.86 kg. The wet cake as a residue has been collected from the wall of filter cloth by using a plastic scrapper. The plates and frames of the plate and frame filter press are pulled apart. The filter cake can be removed. Unpacked the rest of filter plate one by one. In this action, avoid use a sharp object to clean the filter cloth because it will damage the filter cloths. Next, the weight of dry cake for Tray 1 is 1.98kg, for Tray 2 is 1.34kg and for Tray 3 is 1.18kg. After weighing the wet cake, it has been dry until it completely dry. So, the weight of dry cake can be obtained after the wet cake dry. From the data, the weight ratio of wet cake to dry cake (mF/ mc) is 0.787, the density of calcium carbonate (ρ) is 2.93 g/cm3 and the total active filter area is 2. 209m2. For pressure drop, the value is 50psi which is 344.74 kPa. From the experimental results obtained, graphs of t/V versus V are plotted in Figure 1. The equation of the line is y = -0.0197x + 12.368. The slope of line is -0.0197x and y-intercept is 12.368. The graph start to decrease started from t=93s. To check the viscosity and density value from Table 2, the collected filtrate at V= 10L, 50L and 70L was keep separately. The viscosity and density value at V=10L is 0.0128Pa.s and 0.995 g/cm3, at V=50L is 0.02Pa.s and 0.997 g/cm3, and at V=70L is also 0.02Pa.s and 1.001 g/cm3. 7|Page

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Table 3 shows the values of filter medium resistance (Rm) and cake resistance (α). From the calculation, the Filter medium resistance, Rm for Tray 1 is 7.3583x1010 m-1, Tray 2 is 4.7093x1010 m-1, and for Tray 3 is 4.7093x1010 m-1. For cake resistance, α the value for Tray 1 is 10356214.76 m4/kg, for Tray 2 is 6627977.45 m4/kg and for Tray 3 is 6627977.45 m4/kg. there are some factor that influencing the filtration which is properties of solid and liquid in term of density, viscosity, corrosiveness and properties of slid in slurry in term of rate of formation filter cake especially in early stage of filtration (Rita Kudarha,2014). Filter medium resistance can be affect the pressure in filtration process because rate of filtration is proportional to the overall pressure drop across both the filter medium and filter cake according to the K-C equation. A pressure difference could be obtained by maintaining a head of slurry above the filter medium. The pressure develop will depend on the density of the slurry. The pressure below the filter medium may be reduced below atmospheric pressure by connecting the filtrate receiver to a vacuum pump and creating a pressure difference across the filter (Rita Kudarha,2014). The advantages of filter press are the construction of it is very simple and variety of material can be used. It also provides large filtration area in relatively small floor space. The capacity being variable according to thickness of frames number used. Next, operation and maintenance is easy. It also produces dry cake in form of slab and efficient washing of cake is possible. The disadvantages is time for consuming is higher, it is an expensive filter, the operation is critical as the frames should be full otherwise the washing is inefficient and the cake is difficult to remove and it is used for the slurries containing less than 5% solids (Saraswathi.B, 2015). Finally, in order to improve the result of this experiment, the precaution step should be taken.

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5.0 CONCLUSION

The purpose of Plate and Frame Filter Press experiments is to study the operation of filter press for filtration of calcium carbonate slurry and to determine filter medium resistance and specific cake resistance from filtration data obtained. From the recorded data in Table 1, it can be concluded that the time taken increase and t/V decrease when the collected filtrate volume increase. The t/V for filtrate volume starts to decrease slowly not likely the beginning the experiment. The t/V is decrease until the calcium carbonate slurry, CaCO3 is fully used. When the filtrate that come out from the equipment is getting slow, it indicate the volume of filtrate is getting low. From the data, the weight ratio of wet cake to dry cake (mF/ mc) is 0.787, the density of calcium carbonate (ρ) is 2.93 g/cm3 and the total active filter area is 2. 209m2. For pressure drop, the value is 50psi which is 344.74 kPa. . The viscosity and density value at V=10L is 0.0128Pa.s and 0.995 g/cm 3, at V=50L is 0.02Pa.s and 0.997 g/cm3, and at V=70L is also 0.02Pa.s and 1.001 g/cm3. A graph was plotted from the result obtained. The graphs of t/V versus V are plotted in Figure 1. The graph start to decrease started from t=93s. Filter medium resistance can be affect the pressure in filtration process because rate of filtration is proportional to the overall pressure drop across both the filter medium and filter cake according to the K-C equation. A pressure difference could be obtained by maintaining a head of slurry above the filter medium. The pressure develop will depend on the density of the slurry. The pressure below the filter medium may be reduced below atmospheric pressure by connecting the filtrate receiver to a vacuum pump and creating a pressure difference across the filter.

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6.0 RECOMMENDATIONS There are some error occur while doing the experiment such as a miscalibrated balance will cause all the measured masses to be wrong and Bias of the experimenter. The experimenter might consistently read an instrument incorrectly, or might let knowledge of the expected value of a result influence the measurements. Here are suggestion that can do to overcome the problems. A miscalibrated balance always give result too high or low. We can eliminate it by calibrated it properly. The goal of a good experiment is to reduce the systematic errors to a value smaller than the random errors. For example a meter stick should have been manufactured such that the millimeter markings are positioned much more accurately than one millimeter.

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7.0 REFERENCES 1. C.v.s subrahmanyam et al., Pharmaceutical Engineering Principles and PracticesFiltration, 2001, pg260-266

2. Filtration, 1998-2009, Lentech Water treatment & purification Holding B.V, [Online]. [Accessed

29th

March

2016].

Available

from

World

Wide

Web:

http://lenntech.com/chemistry/filtration.htm

3. Cebu Institute of Technology, Chemical Engineering Department, Juphil A. Lamanilao, 2010, p239 4. Filtration, 2014, Ritu R. Kudarha and M. Pharm, [Online]. [Accessed 30th March 2016]. Available from World Wide Web: http://slideshare.net/ritukudarha/filtration39038033

5. Plate and Filter Press , 2016, G.U.N.T Gerätebau GmbH, Hanskampring [Online]. [Accessed

30th

March

2016].

Available

from

World

Wide

Web:

http://gunt.de/networks/gunt/sites/s1/mmcontent/produktbilder/08328700/Datenblatt/0 8328700%202.pdf

6. Plate and Filter Press, 2015, Saraswathi.B, St. John College of Pharmacy, [Online]. [Accessed

31th

March

2016].

Available

from

World

Wide

Web:

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

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APPENDICES SAMPLE CALCULATION From graph of t/ V against V plotted in figure 1, the equation of the line obtained is y = 0.0197x + 12.368. Slope,

Kc 2

= - 0.0197 s/L

Kc = - 0.0394 s/L y-intercept,

1 qo

= 12.368

Equations provided to calculate filter medium resistance (Rm) and cake resistance (α) are as follows, 1 𝑞˳

=

𝜇 𝑅𝑚

Kc =

𝐴 (∆𝑃)

𝜇𝑐𝛼 𝐴2 ∆𝑃

To calculate filter medium resistance (Rm),

i.

For Tray at 10 L, Rm =

1 𝑞˳

Rm =

x

𝐴 (∆𝑃) 𝜇

(12368 s/m3) (2.209 m2) (34474 Pa) 0.0128 𝑃𝑎.𝑠

= - 7.3583x1010 m-1 ii.


1 𝑞˳

Rm =

x

𝐴 (∆𝑃) 𝜇

(12368 s/m3) (2.209 m2) (34474 Pa) 0.02 𝑃𝑎.𝑠

= - 4.7093x1010 m-1 iii.


1 𝑞˳

x

𝐴 (∆𝑃) 𝜇

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Rm =

(12368 s/m3) (2.209 m2) (34474 Pa) 0.02 𝑃𝑎.𝑠

= - 4.7093x1010 m-1 To calculate cake resistance (α),

i.

For Tray at 10 L,

𝛼= 𝛼=

Kc 𝐴2 ∆𝑃 𝜇𝑐 (− 0.0394 s/L) (4.8797 m4) (34474 Pa) 𝑘𝑔 ) 𝐿

(0.0128 𝑃𝑎.𝑠)(0.05

= 10356214.76 (m4/kg) ii.

For Tray at 50 L,

𝛼= 𝛼=

Kc 𝐴2 ∆𝑃 𝜇𝑐 (− 0.0394 s/L) (4.8797 m4) (34474 Pa) 𝑘𝑔 ) 𝐿

(0.02 𝑃𝑎.𝑠)(0.05

= 6627977.45 (m4/kg) iii.

For Tray at 70 L,

𝛼= 𝛼=

Kc 𝐴2 ∆𝑃 𝜇𝑐 (− 0.0394 s/L) (4.8797 m4) (34474 Pa) 𝑘𝑔 ) 𝐿

(0.02 𝑃𝑎.𝑠)(0.05

= 6627977.45 (m4/kg)

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Lab Report Plate and Filter Press

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