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 COMBINING NOZZLE. 31 combining nozzles are made with a taper varying from 15 deg. at the inlet end to 5 deg. at the outlet end. The combining nozzle is subjected to considerable wear if the feed water contains solid matter in suspension. This is especially marked at the point where the steam first strikes the water and drives the solid matter against the sides of the nozzle. The effect is to groo ve the nozzle and change its form. The first or inlet portion of the combining nozzle is therefore frequently made separate from the remainder so that it can be renewed when necessary. Such separate inlet portion is termeel the “ water nozzle,’’ “ draft tube, or “ lifting cone.” This form of combining nozzle is illustrated in fig. 16, where a indicates the “ draft tube.” The combining nozzle has a long life if the feed water is pure. Hence the advantage of carefully filtering the water passing to the injector.