SU1242757A1 - Method of measuring viscosity of suspensions which are easily separated into layers - Google Patents

Abstract

The invention can be used in various industries. A method for measuring the viscosity of easily dispersed suspensions using a rotational viscometer is described, in which the pressure drop to avoid delamination of the suspension is maintained within the exclusion limits. destruction of the suspension structure. 1 il.

Description

one

The invention relates to viscosity measurements and can be used in various industries, in particular in the pulp and paper industry, in measuring the viscosity of such exfoliating suspensions as pigment, soda and others.

The aim of the invention is to improve the accuracy of viscosity measurements of lightly stratifying suspensions.

The drawing shows a device for implementation capable.

The installation contains inner 1 (rotating) and outer 2 (stationary) cylinders, a mixing device 3, a suspension vessel 4, a load 5, a driving drum 6, an axis 7 and a differential pressure gauge 8.

The method is carried out as follows.

When the propeller of the stirrer 3 is rotated, a driving differential pressure rp is created in the working gap, which in the latter generates vertical circulation. At the same time, the suspension is circulated through the volume of the vessel 4, ensuring that the concentration of the solid particles of the suspension is uniform in the whole volume of the vessel. Then, in the suspension, the finding of it, in the gap, the workers initiate the driving forces, by causing the internal cylinder 1 to rotate by the applied torque M, created, for example, by the weight 5 suspended from the thread, wound on the drum 6.

The magnitude of the torque M and the rotational speed of the cylinder h are measured. Next, with the help of a differential pressure gauge 8, the driving differential pressure is measured. If the measured value of the moving pressure drop is within the claimed limits, the viscosity is calculated by the formula:

WITH

where U is the viscosity of the slurry;

t, - shear forces;

b is the velocity gradient, and the shear stresses, o, are made by the formula

definit

2 iiR6-.h

(2)

where M is the torque on the shaft

inner cylinder; h is the working height of the cylinders.

2427572

If it turns out that the measured driving differential pressure is outside the proposed limits, then adjust the moving differential pressure Lp by moving the cylinders 1 and 2 together in a horizontal plane around the axis, their position relative to the agitator 3, at which the measured 10 new differential

 M

Rrcrt

R)

(3)

0

five

0

five

0

S

0

where ip is the driving differential pressure

on the height of cylinder; M is the torque; - the measurement error of the moment;

g) - P4 DIUSES of the inner and on the outer coaxial cylinders of the viscometer, after which the value of the rotational speed of the cylinder is measured again and then the suspension viscosity is calculated.

Example. Using the proposed method, the viscosity of aqueous suspensions of iron oxide pigments with a concentration of 350 g / l and kaolin with a concentration of 270 g / l is measured. 1260 and 1170 kg / m, respectively. Installation characteristics that implement the following: RJI cylinder radii of 3.6 cm; Rg 3.4 cm; working height h 23 cm; vessel volume 3 liters. The working fluid of the differential pressure gauge is carbon tetrachloride (SS) with a gf ratio of 1.72 g / cm The moment at which the rotation of the cylinder starts when the gap is filled with the suspension is M 0.009 kg cm. The accuracy of the measurement of the moment determined mainly by the thickness of the winding thread on drum 6 is 7% O ,, 07. The proposed ratio is as follows:

M cm waters. Art. J kK-H R ()

Consequently, the viscosity measurements obtained for two-sided, one-one ipt differential pressures.

- 0.89 cm water. Art., corresponds to the proposed method. i

Claims (1)

Invention Formula 55 A method for measuring the viscosity of easily stratified suspensions on a rotary viscometer with coaxial cylinders forming an annular working gap by creating a vertical circulation of the suspension in the gap due to a moving differential pressure over its height, driving shear forces, changing the torque on the axis of the rotating cylinder and changing the torque on the axis of the rotating cylinder. rotation and subsequent calculation of viscosity, characterized in that, in order to improve the accuracy of the Measurements, after measuring the torque differential pressure, regulate and maintain it in the interval I Rf (R MG g  R) where Lr is the driving differential pressure; M is the steepest point on the axis rotating the occpindra; the measurement error of the moment M; the radius of the rotating inner cylinder; the radius of the fixed outer cylinder of the viscometer, after which the rotational speed of the inner cylinder is measured again and the viscosity of the slurry is calculated. G R,. .1 |  ". . ; % -. h (R " . % -J -four g f f fir / Y f f fJ -f-J Editor A. Shandor Compiled by V.Voschankin Tehred O.Gortvay Order 3691/38 Circulation 778 Subscription YONIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Rauschska nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 Proofreader S. Cherni