A rotary vacuum filter is available with an area of 200 m^2 and vacuum pressure of 75 kPa. Filter leaf tests have been performed on a cell broth with a viscosity of 5 cP.
The leaf tests gave a specific cake resistance of 1×10^11 cm/g and medium resistance of 1×10^8 cm-1. The cake solids (dry basis) per volume of filtrate was 15 g/L. It is desired to operate the large filter with cycle time of 45 s and a cake formation time of 10 s. What is the filtration rate expected for the rotary vacuum filter? How significant is the resistance medium?
From the given information, we get the following data:
and the area A can be calculated from;
So, at the end of the filtration,
Therefore the filter medium is contributing very little of the resistance to filtration