Centrifuges batch cycle

J4. Reactant liquid is pumped into a batch reactor at a variable rate. The reactor pressure also varies during the batch cycle. Specify the control valve size and the centrifugal pump head required. Assume a flat pump curve. 

The vertical or pendulum perforate basket (Fig. 8) is perhaps the most commonly used centrifuge. The perforated basket in its simplest form is lined with a cloth, wire mesh, or a bag that accumulates solids as the liquid passes through. When the solid space is filled, feeding is discontinued and the relevant portion of the batch cycle is continued. In smaller units, the bowl may simply spin down to a complete stop for manual removal of the cake or replacement of the bag. At higher G-levels or in larger diameter units, wire mesh or screen is added to support the filter media. Slowing the unit and plowing the solids out at low speed complete the batch cycle. Rinse can be isolated... 

For a particulate application involving SLS, how to choose the best equipment, to use batch or continuous operation, which filter medium to select, and what is the optimum operating conditions are concerns of engineers. Although theories are available for some SLS operations, solutions for equipment selection, process design, and optimization are still very much dependent on test and experience, and are frequently qualitative or semi-qualitative. In this section, strategy and decision networks for selection of SLS equipment, introduction of filter media, centrifugal pumps for filtration operation, and selection of filter aids by cycle analysis will be discussed. 

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