You want to use a plate and frame filter to filter an aqueous slurry at a rate of 1.8 m3 per 8 hr day. The filter frames are square, with a length on each side of 0.45 m. The ‘‘down time’’ for the...

You want to use a plate and frame filter to filter an aqueous slurry at a rate of 1.8 m3 per 8 hr day. The filter frames are square, with a length on each side of 0.45 m. The ‘‘down time’’ for the filter press is 300 s plus an additional 100 s per frame for cleaning. The filter operates with a positive displacement pump, and the maximum operation pressure differential for the filter is 45 psi, which is reached after 200 s of operation.

(a) How many frames must be used in this filter to achieve the required capacity?

(b) At what flow rate (in gpm) should the pump be operated? The following lab data were taken with the slurry at a constant P of 10 psi and a 0.05 m2 sample of the filter medium: After 300 s, the total volume of filtrate was 400 cm3 . After 900 s, the total volume of filtrate was 800 cm3 .