Plate & Frame Filter Press Final Report


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Plate & Frame Filter Press Final Report

  1. 1. qwertyuiopasdfghjklzxcvbnmqwertyuiopas dfghjklzxcvbnmqwertyuiopasdfghjklzxcvbn mqwertyuiopasdfghjklzxcvbnmqwertyuiopa sdfghjklzxcvbnmqwertyuiopasdfghjklzxcvb nmqwertyuiopasdfghjklzxcvbnmqwertyuio pasdfghjklzxcvbnmqwertyuiopasdfghjklzxc vbnmqwertyuiopasdfghjklzxcvbnmqwertyui opasdfghjklzxcvbnmqwertyuiopasdfghjklzx cvbnmqwertyuiopasdfghjklzxcvbnmqwerty uiopasdfghjklzxcvbnmqwertyuiopasdfghjkl zxcvbnmqwertyuiopasdfghjklzxcvbnmqwer tyuiopasdfghjklzxcvbnmqwertyuiopasdfghj klzxcvbnmrtyuiopasdfghjklzxcvbnmqwerty uiopasdfghjklzxcvbnmqwertyuiopasdfghjkl zxcvbnmqwertyuiopasdfghjklzxcvbnmqwer tyuiopasdfghjklzxcvbnmqwertyuiopasdfghj klzxcvbnmqwertyuiopasdfghjklzxcvbnmqw CEBU INSTITUTE OF TECHNOLOGY UNIVERSITY N. Bacalso Avenue, Cebu City Chemical Engineering Department FINAL REPORT ChE Lab 2 PLATE & FRAME FILTER PRESS Title of Experiment Juphil A. Lamanilao BSChE-5 Engr. Vera Marie Lanaria Instructor
  2. 2. Abstract: Filter press operates under pressure using the process of cake filtration. This involves sending a slurry through the press, which is equipped with filter cloths. The cloths pick up the particles in the slurry and allow the solvent (water) to pass through. As more slurry moves through the press, the cake builds up and assists the filtration process. The rate at which the slurry moves through the press depends on the viscosity of the liquid, the thickness and resistance of the cake, and the pressure drop across each plate. A positive displacement pump permits the plate-and-frame filter to be fed with a suspension at either a uniform rate or, by adjusting a bypass valve, with a constant pressure. As filtration proceeds, layers of solids build up in the frame while the filtrate passes through the press. However, as more and more solid builds up in the frame, filtration becomes slower and slower. When a sufficient thickness of solids or cake has built up in the frames, filtration is stopped, the press is dismantled and the cake is removed from the frames. The resistance of the cake increases with time as the cake builds up in the frame (i.e. it becomes harder to force the filtrate through the cake, as the cake becomes thicker). At any time, this resistance to the flow of filtrate is proportional to the volume of filtrate that has passed through the cake
  3. 3. Objectives: 1.) To determine how concentration is related to the weight and volume of cake obtained. 2.) To determine how concentration affects the length of time a certain volume of filtrate is obtained. 3.) To plot the volume of filtrate versus time per volume of filtrate. Materials & Equipments: Plate & Frame Filter Press Equipment, water (H2O), & calcium carbonate (CaCO3) Sketch of the Set-up:
  4. 4. Procedure: 1. About 18 liters of slurry was prepared containing 10% by weight of CaCO3 & 90% by weight water. 2. The feed tank was filled with predetermined amount of slurry. 3. The removable head was tightened to lock. 4. The necessary valves (pressure and control valves) were opened. 5. The agitator and the pump were switch on simultaneously. 6. The switch of both the agitator and the pump were turn off when the slurry from the feed tank was already consumed. 7. The procedure was repeated using 20% by weight CaCO3. Tabulated Data & Results: Table 1: Using 10% by weight CaCO3 Table 2: Using 20% by weight CaCO3 Filtrate Vol., Vf (L) Time, sec Rate, Vf/time (L/s) 2 9.82 0.2037 3 17.32 0.1732 4 24.03 0.1665 5 30.24 0.1653 6 36.42 0.1647 7 42.84 0.1634 8 48.35 0.1655 9 54.69 0.1646 10 60.89 0.1642 Filtrate Vol., Vf (L) Time, sec Rate, Vf/time (L/s) 2 12.38 0.1616 3 18.19 0.1649 4 21.95 0.1822 5 26 0.1923 6 29.8 0.2013 7 34.57 0.2025 8 38.6 0.2073 9 43.18 0.2084 10 47.41 0.2109 ρslurry 1.067 g/ml Wt. slurry 19.2 kg Solid in cake 1.92 kg Wt. H2O in slurry 17.28 kg Vol. H2O in slurry 17.28 L P(kgf/cm2 ) 0.55 ρslurry 1.144 g/ml Wt. slurry 20.6 kg Solid in cake 4.12 kg Wt. H2O in slurry 16.48 kg Vol. H2O in slurry 16.48 L P(kgf/cm2 ) 0.60
  5. 5. Computations: From Perry’s Handbook (4th ed.) Table 3-1: SG (CaCO3) = 2.711 g/ml Solving for ρslurry: Assume: 1 g slurry @10% CaCO3: ρslurry = 1 g /[(0.9/1) + (0.1/2.711)] = 1.067 g/ml Solving for Wt. slurry: Ws = Vs ρs Ws = 18 L (1.067 g/ml)(1000 ml/1 L) = 19.2 kg Solving for mass of CaCO3: % by weight CaCO3 =MCaCO3/Ms MCaCO3 = 0.10 (19.2 kg) = 1.92 kg MH2O: MH2O = Ws - MCaCO3 = 19.2 kg – 1.92 kg = 17.28 kg @20% CaCO3: ρslurry = 1 g /[(0.8/1) + (0.2/2.711)] = 1.144 g/ml Solving for Wt. slurry: Ws = Vs ρs Ws = 18 L (1.144 g/ml)(1000 ml/1 L) = 20.6 kg Solving for mass of CaCO3: % by weight CaCO3 =MCaCO3/Ms MCaCO3 = 0.20 (20.6 kg) = 4.12 kg MH2O: MH2O = Ws - MCaCO3 = 20.6 kg – 4.12 kg = 16.48 kg
  6. 6. Data Analysis: This experiment consists of a plate & frame filter to separate slurry of calcium carbonate from water at determined feed pressure of; 0.55 kgf/cm2 using 10% CaCO3 & 0.60 kgf/cm2 using 20% CaCO3. The performance of the filter is characterized by analyzing the filtrate volume versus time per volume of filtrate (see graph above) to determine the specific cake resistance and the degree of compressibility. Based on the graph obtained, the pressure affects the rate of filtration for which an increased pressure would maximize the rate of filtration & produce a final filter cake with a low water content (see red graph). The cloth resistance is generally negligible compared to the cake resistance since the latter increases as the cake gets thicker. Also, decreasing the number of plate/frame would decrease its efficiency as more slurry will produce as filtrate instead of pure water liquid.
  7. 7. Recommendation: The slurry of calcium carbonate and water must be properly mixed using agitator & the feed pump must have its own switch control on/off. The pump should never turn without the feed & the feed pump must have a constant flow rate to ensure a zero value obtained, proving that there is no pressure drop in the filter until the cake begins to build. The key issue in the design of the filter press feed pump is the prevention of air ingress. Leakage of air through the pump shaft seal will allow oxygen to enter the system. The standard method of coping with this problem is to use inline vertical centrifugal pumps, which are submerged in barren solution above the shaft seal. In some cases, a combination of filter cloth coated with filter aid such as filter paper is applied to reach the maximum operating level of the equipment. Application to ChE: Plate & Frame Filter Press is one major pretreatment process for cell separation used in downstream processing as application in chemicals, pharmaceuticals, etc. where Chemical Engineers work on for bioseparations. Also, it is widely preferred in today’s wastewater system not only because it is easy to use and operate but it also offers a clean and effective method to produce wastewater discharge meeting standard regulatory controls. This type of equipment is used for large scale operation under ChE while a chemist uses simple filtration technique, filter funnel (filter paper) in laboratory which would be impractical to build a big such.