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.

THE STEAM INJECTOR, and the nozzle b will be moved away from the steam nozzle; the water inlet area is then increased. It may be here remarked that in order to reduce thø loss in velocity in an injector due to the impact of the steam upon the water, the water supply should be providecl in tlie form of a thin film nioving with a high velocity. The injector water inlet is therefore ahvays made of annular form, and the vacuum at the inlet end of the combining- nozzle maintained as high as possible. This arrangement also ensures a more rapid mixture of tlie steam and water than if the steam issuecl concentricallv around a solid jet of water. A form of automatic water regulator, in which the use of a sliding nozzle is obviated, was shown at fig. 13. hen a vacuous condition exists in the overflow chamber e, the valve f upon the supplementary water inlet passage 9 is opened, and water flows through the overflow chamber into the combining nozzle by way of the slots therein. If. however, tlie pressure in e is equal to or greater than that of the atmosphere, the valve f is held on its seat. A difficulty with the aforesaid type of injector will be at once appraciated if reference be made to the remarks upon overflow arrangements. It was shown that whereas