2.  

A mineral slurry containing 0.5 kg solids (SG = 2.5) per litre of water is fed to a rotary belt filter, 1 m wide and 5 m long. The belt runs at 1 m/min with 20 per cent of its surface used for cake formation. Filtration is carried out under a vacuum pressure of 40 kPa abs. Filtrate is produced at an average rate of 500 kg/h and the filter cake has a voidage of 0.6. a. What average thickness of cake is formed? b. Determine the average specific cake resistance. c. Determine the filter capacity based on solids collected. The belt filter breaks down and filtration has to be carried out temporarily in a plate and frame filter press fitted with 0.5 m x 0.5 m frames. Filtration takes place with a constant feed pressure of 300 kPa abs. Cake washing requires 10 minutes and filter dismantling and reassembling takes 20 minutes. If filtration is to be carried out at the same overall rate as with the continuous filter, determine d. the number of plate & frames required; and e. the thickness of the filter cake formed in each frame. For both filters, assume the filter cake to be incompressible and neglect the resistance of the filter media. For the filter press, assume that cake washing uses a volume of wash water equal to the total volume of filtrate collected. A mineral slurry containing 0.5 kg solids (SG = 2.5) per litre of water is fed to a rotary belt filter, 1 m wide and 5 m long. The belt runs at 1 m/min with 20 per cent of its surface used for cake formation. Filtration is carried out under a vacuum pressure of 40 kPa abs. Filtrate is produced at an average rate of 500 kg/h and the filter cake has a voidage of 0.6. a. What average thickness of cake is formed? b. Determine the average specific cake resistance. c. Determine the filter capacity based on solids collected. The belt filter breaks down and filtration has to be carried out temporarily in a plate and frame filter press fitted with 0.5 m x 0.5 m frames. Filtration takes place with a constant feed pressure of 300 kPa abs. Cake washing requires 10 minutes and filter dismantling and reassembling takes 20 minutes. If filtration is to be carried out at the same overall rate as with the continuous filter, determine d. the number of plate & frames required; and e. the thickness of the filter cake formed in each frame. For both filters, assume the filter cake to be incompressible and neglect the resistance of the filter media. For the filter press, assume that cake washing uses a volume of wash water equal to the total volume of filtrate collected.