SU1416888A1 - Apparatus for feeding pulp sample into measuring tray - Google Patents

Abstract

The invention relates to sample preparation devices for the automatic instrumental analysis of pulp samples and can be applied in areas where chemical analysis or particle size analysis of the pulp is used. The purpose of the invention is to increase the reliability of the analysis of the sample by providing transportation of the pulp sample through the measuring cell without separation of particles by density and size. The device contains a receiving tank 1, an intermediate tank 2, a valve 3 and a pump 4, which is articulated with an intermediate tank with its vertically positioned inlet pipe through the relief valve 5 and pipe 6 with the receiving tank 1. The device is connected by pipes 7 and 8 to a measuring cuvette 9 located above the level of the pulp in the receiving tank 1, and the receiving tank 1 has the shape of a truncated cone with an angle of 25-30. 2 hp f-ly, 1 ill. -3. w (L od 00 OS 00

Description

The invention (more related to sample preparation devices for automatic instrumental analysis of samples of pulp products and can be used in those sectors of the national economy that use automatic analysis of the chemical or granulometric composition of the pulp.

The purpose of the invention is to increase the quality of sample analysis by ensuring that the pulp sample is transported through the measuring cell without separation of particles according to density and size, 15

The drawing shows a diagram of the device.

The device consists of a receiving tank 1 coaxially located on the same vertical, intermediate tank 2 20 with bypass valve 3 and pump 4, which is articulated with intermediate tank 2 with its vertically located inlet pipe and connected by an outlet pipe through valve 5 25 and pipe 6 receiving tank 1.

The device is connected by pipelines 7 and 8 to the measuring cell 9 of the analyzer located above the level of 3Q n of pulp in the receiving tank, while the input pipeline 7 is connected to the receiving tank 1, and the output pipeline 8 to the intermediate tank 2,

Receiving tank 1 is in the form of a straight cone angle

The truncated cone is within the limits of 25-30. The limits of the values for the angle of the cone are established experimentally for the conditions of pulp sample with a volume flow rate of 10-12 liters / min, at which deposition of the solid particles of the cone is excluded.

When the angle of the cone is more than 30 °, the particles are deposited on the walls of the cone, and the accumulation of particles periodically occurs, resulting in the analysis of pulp with varying solids, which reduces the reliability of the analysis

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accumulation 45

mi The lower cone contributes to the safe discharge of the pulp from the intermediate tank, taking into account the velocity of the pulp in the bone, and the upper one - to the concentration of air before it is discharged through the upper opening with the overflow valve open. The volume of the intermediate tank must be not less than the total volume of pipelines in the measuring to the tour, with a cuvette for guaranteed placement in the intermediate tank of the pulp and air contained in the measuring loop.

The device works as follows

In each analysis cycle, the devices operate in two consecutive modes:. Mixing the sample and feeding the sample to the measurement;

The pulp test enters the receiving tank 1, Valve 3 is open, and valve 5 is closed for discharge, the pulp fills all the nodes of the device as communicating vessels, excluding the upper parts of the pipes of wires 6, 7 and 8, as well as the cell 9 located above the pulp level receiving tank

For the operation of the device in the stirring mode, the pump 4 is turned on, which pumps the pulp repeatedly through a closed cycle 1,2,4,5,6,1. The circuit is mixed during the circulation process. The valve 3 is closed, the pump 4 continues to work, selects the pulp from the intermediate tank 2 and the pipeline 8, creating a vacuum in them under the action of which the pulp from the pipe 7 rises and, passing through the cuvette 9, forces the air out of the pipeline 7 and 8 into the upper part intermediate tank 2. After this, pump 4 is turned off, and valve 3 is opened for a short time and air from the intermediate tank exits the shortest way vertically through the receiving tank 1 to the atmosphere. The valve closes. All units of the device, including the measuring circuit: the wires 7 and 8 and the cuvette 9, are free

Similarly, experimentally set-50 from the air and filled with pulp. Then

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mi The lower cone helps to reliably discharge the pulp from the intermediate tank, taking into account the velocity of the pulp in the tank, and the upper one - to the concentration of air before it is discharged through the upper opening with the overflow valve open. The volume of the intermediate tank should be not less than the total volume of pipelines in the measuring circuit, with a cuvette for guaranteed placement of the pulp and air in the intermediate tank.

The device works as follows

In each analysis cycle, the device operates in two successive modes:. Mixing the sample and feeding the sample for measurement;

The pulp test enters the receiving tank 1, the valve 3 is open and the valve 5 is closed for discharge, the pulp fills all the nodes of the device as communicating vessels, excluding the upper parts of pipelines 6, 7 and 8, as well as the cuvette 9 located above the pulp level tank,

For the operation of the device in the mixing mode, the pump 4 is turned on, which pumps the pulp repeatedly through a closed cycle 1,2,4,5,6,1. The sample is stirred during the circulation process. The valve 3 is closed, the pump 4, continuing to work, selects the pulp from the intermediate tank 2 and the pipeline 8, creating a vacuum in them, under the action of which the pulp from the pipeline 7 rises and, passing through the cuvette 9, forces the air out of the pipeline 7 and 8 into the upper part of the intermediate tank 2. After that, the pump 4 is turned off, and the valve 3 is opened for a short time and the air from the intermediate tank leaves the shortest path vertically through the receiving tank 1 to the atmosphere. Valve 3 is closed. All units of the device, including the measuring circuit: piping 7 and 8 and cuvette 9, are free

The most appropriate limits for the height of the cone depending on 20-25 diameters of the hole through which the pulp leaves the receiving tank were added.55

Intermediate tank 2 consists of two truncated straight circular cones. Connected by large bases, the pump 4 is turned on to dissolve the dissolved air from the pulp. A vacuum is formed in the measuring loop (7.9.8). The dissolved air is released into the bubbles, which enter the intermediate tank. 2, The pump 4 stops, the valve 3 opens and the air is discharged through the receiving tank.

The device and the pulp are prepared for operation in the mode of repeated pumping of the sample through the measuring cell 9 (for the time required for the measurement). The operation of the device in this mode begins by turning on pump 4 and simultaneously closing valve 3.

At the end of the measurement, the valve 5 and the valve-switch 3 open, and then the pump 4 stops. The pulp test is discharged from the device through the valve valve 5.

In case of a film breakthrough in the window of the cuvette 9, the pulp due to the vacuum in the measuring circuit flows, respectively, from the pipeline 7 to the receiving tank 1 and from the pipeline 8 to the intermediate tank 2, i.e. the instrumentation is reliably protected from the pulp.

The operation of the device is controlled automatically according to the sequence diagram, taking into account the set time for preparing the pulp sample and the device (mixing, air discharge from the measuring circuit in two steps), for circulation through the cell, taking into account the time for exposure required for measurement and for discharge of the pulp sample. .

Claims (3)

1. Device for supplying a pulp sample to an automat measuring cell 0 tic analyzer, including a receiving tank, a centrifugal pump, a bypass valve, a measuring cuvette with inlet and outlet pipelines, installed above the slurry level in the receiving tank and connected to its lower part by means of an inlet pipeline, characterized in that, in order to increase the accuracy of the sample analysis, ensuring transportation of the pulp sample through the measuring cell without separation of particles according to density and with large scale, the device is equipped with an intermediate tank installed in accordance with bo ttom of the receiving tank, the pump inlet connected to the outlet of the intermediate container and its upper part is connected with the measuring cuvette outlet conduit, wherein the bypass valve is placed in the upper part of the intermediate container. I 2. The device according to claim 1, characterized in that the receiving tank has the shape of a truncated straight cone, the smaller base of which is the entrance to the intermediate tank, wherein the angle of taper is between 25-30 °, and the ratio of its height to the smaller diameter is in the range of 20-25. 3. The device according to claim 1, characterized in that the intermediate tank is filled in the form of two straight truncated cones connected by large bases, forming a volume equal to the total volume of the measuring circuit pipelines. five 0 five