SU99495A1 - Device for measuring pulp density in a tank - Google Patents

Description

Already known are devices for eliminating the density of liquids, based on measuring the weight of a column of liquid, which is determined but not by the pressure drop and at two points itOBi icoTc contains the liquid of the vessel. As a measuring instrument, a differential pressure gauge of some kind of a fusion type is usually used, the impulse tubes of which are connected to the vessel containing the controlled liquid at 1) its points. To prevent the controlled fluid from affecting the mechanism of the instrument, the latter is usually filled with a neutral fluid and connected to the medium under measurement when UOMOHU-I is divided. PEN vessels preventing displacement of liquids. It is also known, in particular, to use for: Separating fluids of elastic non-suburban-type diaphragms enclosed in separating vessels and freely transmitting a pressure impulse to the moving system of the device.

 A feature of the described device for measuring the density of the pulp is that, to prevent scopes, a type of solid pulp tea is about

diaphragms, each dividing; The vessel is connected to the reservoir npii iomoyi-1 of two pipes, one of which is 1) asio.teni in the bottom, and the other on the side of the vessel.

Pia FIG. 1 shows the described device; in fig. 2 shows the Koii-line used in the differential pressure gauge in ycTpoii on the type of ring weights.

Controlled pulp flows through the vertical section of the flow line / from bottom to top. Between the lower and upper parts of the pipeline at points 2 and 3, a difference in hydrostatic pressure is created. This differential pressure is transmitted to the differential pressure gauge 4 through the divide; 1 devices.) And 6, which prevent penetration of the solution or pulp into the differential meter, and the impulse tubes 7, through which the pressure is transmitted to the differential pressure gauge.

Separating devices consist of steel cylindrical vessels, welded to the pipe line with the help of branch pipes: lateral S and lower 9. Elastic are fixed to the separating vessels, separating vessels:: 5-thin-walled bags 10 of alkali-resistant or acid-resistant reg, iiy. MemKi are poured with water, and they are connected through nozzles in the lids of vessels with water-filled pulse tubes attached to an annular differential pressure gauge. Outside, the rubber bags are washed with a solution or pulp that has entered the separation vessels through the connecting pipes.

The magnitude of the pressure difference in both separation vessels due to the weight of the column or solution. The weight of a column of solution or pulp is defined as the product of the difference in height between the separation vessels and the specific value of the solution or pulp.

When a pulp or solution moves in a controlled section of the pipeline (from the bottom up), in addition to the pressure difference due to the density of the pulp, there is an additional loss of pressure due to the friction of the solution or pulp against the pipe walls. This head loss increases the pressure difference measured by the differential pressure gauge, creating a significant measurement error.

The magnitude of the pressure loss depends on the square of the flow rate of the solution in the pipeline. Calculations show that at a speed of less than 0.3 m / s, this value can be neglected for practical purposes. Dia. 1 of reducing the velocity of the solution and the pulp in the measuring section of the pipeline, the latter is performed with a much larger (5-6 times) section than the main pipeline through which the pulp or solution is pumped, as shown in FIG. I.

As a measuring device in the proposed device, a conventional differential pressure gauge of the ring weigher type can be used. For practical purposes, it is often necessary to choose a large unit as the minimum measured density value on the instrument scale. In this case, an additional load 12 is embedded in the ring differential pressure gauge 4, in addition to the load 7 creating the main moment of the receiver, suspended on a flexible steel tape 13, the end of which is fixed on an arc concentric with the center of the differential pressure gauge. The installation of this additional threat makes it possible, in cases where the minimum value of the measured density is greater than 1.000, to eliminate the part of the scale that is useless in this case, from 1,000 to the minimum density value from which the measurements begin. If the minimum measured value of the density of a solution or pulp is equal to the density of water or other working fluid (for example, a mixture of water and glycerin), which is filled with separation bags, impulse tubes and the cavity ring of a differential pressure gauge over mercury, the use of additional weight is unnecessary. The differential pressure gauge is associated with self-recording equipment 14.

Subject invention

Claims (3)

1. A device for measuring the density of the pulp in a tank by measuring the differential pressure over the height of the pulp column with a differential pressure gauge connected to the tank by means of separating vessels located at pressure take-off points on the tank or pipeline and provided with elastic diaphragms to separate the pulp from the working fluid of the differential pressure gauge, the fact that, in order to prevent the accumulation of solids in the pulp around the diaphragms, the separation vessels are connected to the tank with two tubes, one of which is located at the bottom, and the other side of the vessel. 2. The form of the apparatus according to claim 1, different from those. that, in order to reduce the error caused by the movement of the pulp, the section between the sites of separation of the vessels to reduce the speed of movement of the pulp is made of an increased section. 3. The form of execution on PP. 1 and 2, characterized in that, with the compensation of the constant part of the error created by the movement of the controlled pulp, a differential pressure gauge in the form of ring weights with an additional load on the moving system is used to zero the instrument. L l / i. FIG. 2