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.

114 THE STEAM INJECTOR. Tö determin© the quantity of steam available per minute from an ©ngine for working an injector, the area of the engine piston is multiplied by the speed of the piston, i.e., area in feet x stroke in feet x 2 x number of revo- lutions per minute. Thus an engine having a piston of 15 in. diameter, stroke 2 ft. 6 in., and running at 80 revolutions per minute will provide about 491 cubic feet of steam per minute. The following table shows the quan- tity of steam required and the amount of water delivered by the various sizes of exhaust injector. If, however, the engine supplying the- injector with steam is lightly worked, or cut-off takes place earlier than half stroke, the available quantity of exhaust steam found by the above method should be halved before using tlie table. TABLE IX.—Table showing Steam required and Water DELIVERED FOR EACH SIZE OF ExHAUST INJECTOR. Size of injector. Maximum amount of water delivered per hour. Minimum quantity of exhaust steam required per minute. Nnmber. Gallons. Cubic feet. 2 60 26 3 150 60 4 270 100 5 420 156 6 600 225 7 830 306 8 1,080 400 9 1,370 506 10 1,700 625 11 2,050 756 12 2,450 9C0 13 2,870 1,056 14 3,330 1,225 15 3,S20 1,406