The Steam Injector
A theoretical and practical treatise on the design and operation of injectors and on the flow of fluids through and the design of nozzles.

WATER CONTROL ARRANGEMENTS. 73 a vacuum always exists during normal working conditions at the overflow slot near to the inlet end of the combining nozzle, a vacuous condition, atmospheric pressure, or a pressure greater than atmospheric, may exist at the gap between the combining and delivery nozzles. Obviously, therefore, one part of the overflow cliamber will always be tending to draw in additional water, and the other part may or may not be so doing. In the arrangement illustrated at fig. 52 the supplemen- tary water inlet passage a leacls to a point between the lifting and forcing steam nozzles c and d. If the vacuum at that point is sufficiently great to open the valve e a supplementary inflow of water will take place. Otherwise only the water inlet f supplies the injector. Another arrangement of the water inlet connections to overcomc the objection aforesaid is shown at fig. 53. In this the supplementary water supply passage a communi- cates witli a compai’tinent of the overflow cliamber con- taining the overflow gap 6, at which during normal work- ing a vacuum always exists. The supplementary water