CIRCULATING PUMPS.
The definition of the word circulationconveys the best idea of this mechanism—“The act of moving in a circle, or in a course which brings the moving body to the place where its motion began,” hence, a circulating pump is one which causes the water to flow through a series of pipes or conduits, as for example, the water in a steam boiler as in the Ahrens Fire Engine, see page 126, Fig.426, or in marine boilers, or forces cooling water through a surface condenser.
A centrifugal pump driven by an independent engine, see page 219, Fig.497, is generally used for the latter purpose.
Fig.454A.
Fig.454A.
The annexed engraving, Fig.454A, represents a circulating pump attached to a salt water evaporator and distiller for recovering fresh water at sea. The pump at the lower right-hand corner of the engraving takes salt water through the suction at the bottom and passes it upward through the condenser and overboard through the circulation discharge.Any steam pump having a sufficient capacity may be used as a circulating pump.