GB257352A - - Google Patents

Abstract

257,352. Leask, J. P., and Warner, S. T. June 2, 1925. Testing viscosity of liquids.-The viscosity of a fluid is controlled by varying the temperature of the fluid and regulating the variation of temperature by the viscosity of the fluid itself. A fluid tank 1 is provided with a heater 2 supplied with a heating medium through a pipe 3 and valve 4 which may be hand controlled or controlled automatically by pressure. A pump 5 forces fluid from the tank through the pipe 6 to a place where the fluid is in use. A pipe 8 having a double constriction 7, 7<a> is connected to the pipe 6 on the discharge side of the pump and leads back to the tank 1. Pressure gauges 11, 12 are placed on opposite sides of the constriction 7. From between the constrictions 7, 7a a branch pipe 10 leads to the pressure regulator 4<1>. The greater the viscosity, the greater the difference of pressure on either side of the constriction, and consequently this pressure difference may be made to control the valve 4 in such manner that the greater the viscosity the larger amount of heating medium is passed, the effect being to reduce the viscosity. In a modification, the gauges 11, 12 are placed on opposite sides of a constriction in the pipe 6 and the valve 4 is controlled by hand. In other forms, a long length of the pipe 6 is included between the gauges; the heater is placed on the delivery side of the pump; and the method is applied to an open tank feeding by gravity.