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.

PRINCIPLES OF THE INJECTOR. 83 follows. taking 1 Ib. pressure per square inch to be tlie equivalent of a fluid head of 2'3 ft: — V = x p x 2-3 i.e., V2 = 2 g x p x 2'3 V2 . V2 / •• x p ■= ---------- = ----- .... (XXVll.) L 2 g X 2'3 148 V 7 where p = pressure in pounds per square inch, g — acceleration of gravity = 32'2 ft. per second2, and V = velocity in feet per sécond. The following- table gives the weight of 1 cubic foot of water at different temperatures, and the fluid head equivalent of I Ib. pressure per square inch: — Table VII. Tempera- ture. Deg. F. Weight, in Ibs., of 1 cub. foot. Head, in feet,! equivalent of: l Ib. piæssure, per i-q. inch.j Tempera- ture. Deg. F. Weight, in Ibs., of 1 cub. foot. Head, in feet, equivalent of 11b. pressure per sq. inch. 32 62-418 2-307 125 61-654 2-335 35 62-422 2’307 150 61’201 2’355 40 62'425 2-307 175 60’665 2-374 45 62-422 2-307 200 60-081 2’402 50 62-409 2’307 212 59’64 2’414 60 62-372 2-309 250 5875 2-451 75 62-313 2-313 300 56-97 2-528 90 62-133 2’318 400 54’25 2'655 ICO 62-022 2'322 500 51-16 2’81 Let us now examine the action of an injector from a thermal standpoint, which is the most important, as the iriöthod previously adopted ignores altogether the question of the heating effect of the steam. The> total heat energy utilised in an injector is that of the entering steam plus that of the supply water. Such.