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Applications of the Giffard Injector

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This anomaly in mechanics is capable of a number of applications, and has been applied to uses not probably contemplated, originally, by the inventor. The main object was to enable a steam boiler to feed its own water by a jet of live steam. In some cases this proves to be an excellent method, but is not capable of general application. Where it can be applied it is economical and effective. The Morton Ejector Condenser, invented by Mr. Alexander Morton, of the firm of Neilson Brothers, Glasgow, Scotland, has worked finely in supplying boilers by their exhaust steam. It is a modification of, or rather an improvement on, the Giffard injector. A short time ago the application of the Giffard principle was extended to the raising of water by means of a water jet supplied from a head of considerable hight and was fully tested in France with excellent results. In Sheffield, England, the water is supplied from a head of 240 feet the jet being only one-eighth of an inch in diameter, the throat into which it discharges being three quarters of an inchin diameter. The suction and delivery pipes are two inches diameter, the water being drawn through the suction pipe from a depth of fourteen feet. The efficiency of this apparatus is claimed to be very great; that it delivers 72 per cent of the power expended, a duty considerably greater than that of pumps usually employed. The ejector is in use, also, for discharging ashes and scoriae from the boiler room of ships. A pipe of sufficient capacity, three or four inches diameter, extends from the outside of the ship, above the water line, down to the fire-room floor, ending therein a funnel-shaped mouthpiece, just above which is a pipe leading from the boiler to introduce a steam jet. The discharge pipe is furnished with proper valves not necessary to explain as every engineer understands the use of flap, or check valves. Even at ten pounds pressure to the square inch the force is sufficient to lift the debris of the boiler furnaces. The quantity of the steam that passes up the pipe is very small compared with the volume induced by its velocity. Of course, this apparatus can be readily adapted to the discharge of ashes from stationary boilers, and also for excavating sand and gravel under water for the purpose of sinking cast-iron foundations. It is evident that, with modifications, the principle of the Giffard injector may be applied to many uses to which it is not now generally applied.

Scientific American Magazine Vol 20 Issue 11This article was published with the title “Applications of the Giffard Injector” in Scientific American Magazine Vol. 20 No. 11 (), p. 169
doi:10.1038/scientificamerican03131869-169b

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