Patent GB-721066-A (GB)
Title: Apparatus responsive to variations in the viscosity of a fluid
IPC: F15B21/045
Filed: 1952-10-07
Abstract: 721,066. Electric viscosimeters. MAATS C H A P P I J VOOR KOLENBEWERKING STAMICARBON N.V. Oct. 7, 1952 [Oct. 9, 1951], No. 25069/52. Class 40 (1) [Also in Groups XIX and XXIX]  An electric viscosimeter comprises a flow-pipe 1c, Fig. 6, in which at least two flow-resistors 2c and 3c are present, the resistances of which vary differently with variations in the viscosity of the fluid flowing through the pipe 1c; and parts 51, 51a, the movements of which are dependent on changes in the relationship of said resistances to one another (a) when the total pressure drop over the resistors when they are in series (as illustrated for example with reference to Fig. 6), or (b) when the pressure drop over each of the resistors when they are in parallel (as illustrated for example in the arrangement described later with reference to Fig. 7) is kept substantially constant. As shown in Fig. 6, the pressures drop across the flow-resistor 3c acts on diaphragms 50 and 50a to affect the inductances 52 and 52a in the two arms of a Wheatstone Bridge 53. The viscosimeter may alternatively electrically actuate a signalling, regulating or other device.  Flow-resistors. At least one of the flowresistors is a throttling valve 2c whose aperture can be varied and at least one of the flow-resistors is a rotation chamber 3c as hereinafter defined Rotation chamber. This is a chamber bounded by a continuous surface of revolution and having a discharge aperture or apertures so constructed that when the fluid is fed thereinto under pressure the fluid is set in rapid rotation, with the flow moving spirally inwards towards the axis of the chamber with the angular velocity increasing as the radius of rotation of the flow decreases, the chamber having the characteristic that its resistance to the fluid flow decreases with increase in viscosity of the flowing fluid. The rotation chamber 3c, shown in Fig. 6, is tapered and has a central discharge aperture in its apex, there being one or more tangentially directed feed pipes which open into the wider end. The rotation chamber 56, shown in Fig. 7, has centrally arranged circular discharge apertures 34 (one in each opposite end) and one or more tangentially directed feed pipes 33 or feed slots whose centre lines lie in the plane of symmetry. Another form of rotation chamber, Fig. 4, has tangentially directed feed and discharge pipes 37a and 39, that portion of the chamber associated with the feed pipe being of greater radius than that part associated with the discharge pipes. Flow-resistors in parallel. Fig. 7 shows two flow-resistors 55, 56 in parallel whose coefficients of resistance vary differently with varying viscosity, so that whilst the pressure drops over these two resistors are equal, if said pressure drop is kept constant the quantities of fluid flowing simultaneously through the flow-resistors is a measure of the viscosity of the fluid. The two disc-shaped members 59 and 60 are responsive to the fluid flow through the two branches to exert a force on a piston rod 58. Movement of the piston rod 58 may affect the balance of a Wheatstone Bridge.