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.

12 THE STEAM INJECTOR. To obtain the best results, the inlet edge of the steam nozzle should be slightly rounded, so as to obviate the setting up of eddy motions at the nozzle throat. If the inlet edge is excessively rounded, there is probably a cliok- ing action in the nozzle resulting in velocity loss. In Rosenhain’s experiments before referred to, the be-st results were given by nozzles having only slightly rounded inlet edges. Figs. 8 to 11 illustrate various forms of steam nozzle as used in live steam injectors. There would appear to be no necessity for the excessive length and convergence of the inlet end of some of the steam nozzles employed in in- jectors* (except it be that a hexagon is required on the nozzle exteriör). Fig. 12 shows the form of nozzle which gave the best all-round results in Rosenhain’s experiments. The velocity of discharge of the steam from the exit * A nozzle having a well-rounded inlet discharges more steam in a given time than a nozzle ha ving only a slightly-rounded inlet, and likewise a nozzle having: the latter form of iulet discharges more steam than one ha ving a Sharp inlet.