Compression-permeability cell

Parameters q and W are variables when filtration conditions are changed. Coefficient (rj, is a function of pressure (rj, = f(P). The exact relationship can be derived from experiments in a device called a compression-permeability cell. Once this relationship is defined, the integral of the right hand side of the above equation may be evaluated analytically. Or, if the relationship is in the form of a curve, the evaluation may be made graphically. The interrelation between W and P, is established by the pump characteristics, which define q = f(W) in the integral. Filtration time may then be determined from dq/dt = W, from which we may state ... 

The constants a0, k, and n are determined most simply in compression-permeability cells as explained in Section 11.4, but those found from filtration data may be more appropriate because the mode of formation of a cake also affects its resistivity. Equations (11.14) and (11.2) together become... 

Laboratory Testing and Scale-Up 317 Compression-Permeability Cell 317 The SCFT Concept 317... 

Figure 1 show the compression permeability cell used in the experiment. The vacuum filtration apparatus comprises a principal base, a cylinder of 60mm diameter and a perforated plate. Figure 2 shows the vacuum filtration equipment. To produce the filtered cakes of FGM, a mixed slurry consisting of two components was sucked continuously by a vacuum pump through a filter paper extended over the perforated plate. 

Figure 1. Schematic diagram of a vacuum filtration apparatus and a compression permeability cell...

In the experiment reported here, slurry was added in six stages. After a graded filter cake had been formed, a piston was inserted into the cylinder of the apparatus, producing the compression permeability cell shown. The cake was compressed by applying mechanical pressure to the piston. The compressed cakes were air dried and then baked in an electrically powered reducing furnace. 

Riddick, Thomas M. 1968. Control of colloid stability through zeta potential. New York Zeta Meter Inc. Risbud,.. 1974. Mechanical expression, stresses at cake boundaries and new compression-permeability cell. PhD diss.. University of Houston, Texas. 

Tiller, F.M., S. Haynes, and W.M. Lu. 1972. The role of porosity in filtration vii effect of side-wall friction in compression-permeability cells. AIChE Journal 18 13-19. 

Figure 2.24a Porosity with applied pressure by means of a compression permeability cell [Murase et al, 1987]...

The compressibility of cakes, i.e. the increasing resistance of cakes with pressure, can be tested in various ways. As was briefly mentioned in section 9.2.2, one way of testing the relationship a =/(Apc) is in the compression-permeability cell. The solids compression is created by the mechanical action of the piston—an obvious assumption made is that hydraulic pressime can be simulated by mechanical compression. 

Wall Friction in Compression-Permeability Cells, PhD dissertation. University of Houston, Texas, 1966. 

W.M. Lu, Theoretical and Experimental Analyses of Variable Pressure Filtration and the Effect of Side Wall Friction in Compression-Permeability Cells, PhD dissertation. University of Houston, Texas, 1968. 

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