From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Series of tests on an injector's performance with an underslung condenser and varying hotwell positions.
| Identifier | ExFiles\Box 179b\4\ img003 | |
| Date | 1st February 1933 | |
| -3- above it. In any case, whatever the efficiency of the injector, it could only suck steam if it was mounted above the hotwell and the hotwell was uncooled. The best series of tests were done on the Universal Ranger using an injector with nozzle diameter 0.17" and venturi throat diameter 0.275". The first test was with an underslung condenser and a hotwell 5' 9" below the water pump. With this system the injector worked well with an ample margin at engine speeds from 1245 to 2500 R.P.M. It was then required to test with a hotwell 3' below the pump. To obtain this it was necessary to mount the condenser above the engine with a condensate drain into a hotwell 3' below the pump. The hotwell was open to atmosphere and a steam trap was placed in the circuit to prevent the steam short-circuiting from the bottom of the condenser to atmosphere via the hotwell. With this arrangement the injector dealt with the condensate above 950 R.P.M., the margin being such that at 1400 R.P.M. it would empty the hotwell at the rate of 1 1/2 gall/min. A test was done to find out how much condensate could be allowed to collect in the hotwell before the header tank became almost empty and the horn-pipe pressure dropped. 3 1/2 galls. collected before the horn-pipe pressure was reduced, and on opening up, this amount was injected back into the system in just over two minutes. The measurements of condensate flow and injector capacity are shown on the attached graph. A cock was included in the circuit between the hotwell and the injector. On closing the cock the time for 1/2 gall. condensate to collect was clocked. Opening the cock and clocking the time taken to empty the hotwell gave the safety margin of the injector capacity. Hs{Lord Ernest Hives - Chair}/T.P.de Paravicini | ||