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.

58 THE STEAM INJ ECTOR. separate and entirely independent compartment c, having a free non-return valve cl thereon. A discharge through the valve cl can take place whenever the pressure at a exceeds that of the atmosphere. This will only be when the injector is starting or “ knocks off.” A second over- flow aperture is controlled by a flap e, and a third, namely f, discharges into the chamber g, having a valve h thereon loaded through the piston and lever i j by the pressure in the delivery chamber k. The areas of the piston i and valve h are such as ensure the opening of the valve when starting. The valve cl opens independently of the valve h. Throttling of the lifting steam jet is thus entirely obviated. Fig. 36 shows a right-hand vertical combination injec- tor of the type illustrated1 at fig 35, and fig. 37 a non- lifting injector of this type. Fig. 35. In the arrangement shown at fig. 38 the delivery nozzle a slides through the wall b under the influence of the dif- ference of the pressures at its two ends, that at the delivery end being in part counteracted by the spring c. When the injector is starting, the steam from the lifting nozzle cl escapes freely past the flaps e, whilst the nozzle portions f and a slide towards the delivery end of the appliance, being assisted by the spring c. When the injector is working normally tlie- flaps close and the nozzle portions f a slide towards the injector inlet end, as shown; all communication between the interiör of the combining nozzle and the overflow chamber e is then cut off.