ABSTRACT
It is often necessary to transfer a solution from one vessel to another by means of a pump (gravity flow should be provided where possible), or to pump slurry from one vessel to another or from the precipitation vessel to filtration facilities. When transferring a solution, there is no problem relating to the shearing of the precipitate, and as a consequence, a high-speed centrifugal pump is quite satisfactory. By contrast, when a slurry of a precipitate or a suspension of a molecular sieve is being transferred or withdrawn from a tank, care must be taken to avoid the structural alteration that can be caused by shearing or abrasion. As a consequence, in pumping slurries, it is necessary to consider other types of pumps such as a reciprocating, diaphragm, or lobe pump or a screw-type pump with rubber housing such as the Moyno pump. The diaphragm and Moyno pumps are pictured in Figs. 10 and 11, respectively. There are many manufacturers of each type of pump, and these are tabulated in the Chemical Engineering Equipment Guide.
