impellern.

1686 R. Boyle Free Enq. Notion Nature vi. 215 By other portions of matter (which are also extrinsical impellers) acting on them.

1707 S. Clarke Second Def. Argument 31 Is it possible to be an Effect produced without a Cause? Is it impelled without any Impeller?

1799 R. Southey Select. from Lett. (1856) I. 77 The first Impeller of all motions.

1889 F. W. Farrar Lives Fathers I. i. 32 Clement is a moderator, Ignatius an impeller.

1890 P. R. Björling Pumps 190 The pump being charged with water, the impeller or fan is set in motion at a great speed, imparting centrifugal motion to the water contained in the impeller, and so driven into the casing or body of the pump.

1904 Electr. Rev. 27 Aug. 318 It [sc. the conoidal pump] is somewhat different from the ordinary centrifugal pump, due partially to the widening of the pump chamber to admit a special form of impeller.

1909 Westm. Gaz. 30 Nov. 5/1 The full movement on each impeller corresponds to an angle of 90 deg.

1923 Daily Mail 13 July 12 Cooling is by the thermo-syphon system assisted by a water impellor.

1934 Archit. Rev. 75 203 Fresh air..is drawn into the eyes of the fans—the largest of which has a capacity of 641,000 cu. ft. of air a minute and an impellor diameter of 28 ft.

1942 R. A. Beaumont Aeronaut. Engin. 100/1 The mixture, thrown outwards at high velocity by the rapidly revolving impellor, passes through diffuser vanes into a chamber, from which it is delivered to the induction pipes.

1947 A. W. Judge Mod. Gas Turbines viii. 206 The compressor has a double-sided impeller with twenty-nine vanes on each side which enables the maximum air intake area to be obtained for a given tip diameter.

1956 W. L. McCabe & J. C. Smith Unit Operations Chem. Engin. vi. 282 In these machines mixing is done by a mechanically driven impeller, which creates a flow pattern in the liquid.

1956 W. L. McCabe & J. C. Smith Unit Operations Chem. Engin. vi. 283 The three main types of mixing impellers are paddles, turbines, and propellers.

1966 McGraw-Hill Encycl. Sci. & Technol. (rev. ed.) V. 334/2 A fluid coupling consists of an impeller on the input or driving shaft and a runner on the output or driven shaft... Impeller and runner are bladed rotors, the impeller acting as a pump and the runner reacting as a turbine.