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US 4,439,325 AGranted
Pressurized filtration system
AssigneeCPC Engineering Corporation
InventorNorman J. Blais
Life of this patent
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AssigneeCPC Engineering Corporation
InventorNorman J. Blais
Estimating the term…
A method and apparatus for controlling the operation of a primary filter press to insure the attainment of a desired quality cake in the press including a conduit for feeding a slurry or composition to the filter press, transducers responsive to the volume of slurry delivered to the filter press, the rate of flow, the pressure at the inlet to the press and the characteristics of the slurry solids for producing electric signals proportional thereto, relating at least certain of the signals to compute a quantity K indicative of the quality of the cake being formed in the press when the pressure to the filter press attains 90% of the terminal pressure and modifying the characteristics of the slurry to achieve the desired volume of K. The invention further comprehends the use of a pilot filter press of significantly smaller size than the primary press and fed by the same slurry and operated in the same manner. Since 90% of the terminal pressure in the pilot filter can be achieved in a very short time as compared with the primary press, the quantity K can be computed and adjusted long prior to the attainment of 90% of the terminal pressure in the primary filter press.
Means for filtering a liquid-solids composition utilizing a cyclically operated filter press of a known volume having an inlet and outlet and a recommended terminal pressure of the composition fed to said inlet and determining the quality of the cake formed in said filter press comprising means for measuring the volume of the composition delivered to said filter press, the concentration of particulates contained in said composition and the density of said particulates, computing means for determining the percent of the dry solids CS per unit mass of cake contained in the volume of said filter press, means for measuring the elapsed time t.sub.e of the filtering cycle, means for measuring the pressure of composition fed to said filter, computing means for determining a quantity K representing the rate at which the liquid will permeate the cake being formed according to the following equation when said pressure is equal to at least 90% of the recommended terminal pressure:
In the filtration of a liquid-solids composition utilizing a cyclically operated filter press of a known volume having an inlet and outlet and a recommended terminal pressure of the composition fed to said inlet, the method of determining the quality of the cake formed in said filter press comprising the steps of measuring the volume of the composition delivered to said filter press, the concentration of particulates contained in said composition and the density of said particulates, determing the percent of the dry solids CS per unit mass of cake contained in the volume of said filter press, measuring the elapsed time t.sub.e of the filtering cycle, measuring the pressure of composition fed to said filter, determining a quantity K representing the rate at which the liquid will permeate the cake being formed according to the following equation when said pressure is equal to at least 90% of the recommended terminal pressure:
Dependencies are inferred from the claim text.