GB842710A - Viscosity meter - Google Patents

Abstract

842,710. Viscosimeters. FISCHER & PORTER CO. Aug. 20, 1956, No. 25416/56. Class 106 (2). A viscosimeter has an upright metering tube 6, a viscosity-sensitive float 11 therein, the tube and float together forming a passageway, the effective cross-sectional area of which increases as the float 11 approaches the outlet end 27 of the tube 6. A differential pressure regulator 20 is shunted across the inlet and outlet of the tube 6 and means 31 from a flow-restricting orifice in series with the tube 6, the pressure-drop across the orifice 31 being substantially greater than the pressure drop across the metering float 11, a relatively constant pressure drop across the orifice 31 and the metering tube 6 being provided. Fluid to be tested enters the system at 18 and flows along conduit 29 to the vertical tapered tube 6 containing a viscosity-sensitive float 11. It then flows along conduit 30, through a fixed orifice 31 and out of the system at 19. A differential pressure regulator comprising a float 22 in a wide-angled tapered bore 21 of a sleeve 20 and carrying a load 25 immersed in the fluid forms a by-pass from the inlet 18, through the bore 21 and holes 44 in the wall of the sleeve 20, to the outlet 19. Since the float 22 is subjected to the difference between the pressures at the inlet 18 and at the orifice 31, it will rise against the action of the load 25 and allow more fluid to by-pass the measuring tube 6 if this difference increases, and will fall if this difference decreases. Thus the differential pressure-regulator maintains a constant difference between the inlet and outlet pressures of the measuring tube 6 and so maintains a constant rate of flow through this tube. The float 11 thus gives an indication of the viscosity of the fluid, and may also be used to operate a recording instrument or control the viscosity of the fluid. Various kinds of float 11 are described and the tube 6 may be plain or may have guiding surfaces formed therein. Specifications 582,215, 610,708, 615,414, 615,518, 623,927, 634,800 and 636,556 are referred to.