RU1770824C - Device for determining density of liquids and gases - Google Patents

Abstract

Usage: chemical, gas, metallurgical industry. SUMMARY OF THE INVENTION: the device comprises two containers with overflow and drain pipes, a control unit, two valves, a pressure meter and a secondary device. The test liquid is periodically fed into one of the containers, the hydrostatic column is measured and compared with the hydrostatic column of the reference liquid in another vessel. 1 ill.

Description

The invention can be used in chemical-technological processes of the chemical gas, metallurgical and other industries.

A device for measuring the density of liquids and gases is known, comprising a flow tank filled with a liquid in which a hollow cylinder is suspended suspended at one end of a lever. A weighing unit operating on the principle of force compensation is installed at the other end of the lever, the output of which is an analog pneumatic signal proportional to the density of the measured liquid, recorded by a secondary device.

The disadvantage of this device is the insignificant range of density measurement, equal to 0.1-0.3 kg / cm3, in the density range 0.5-1.8 kg / cm, depending on the pressure head arising from the continuous flow of the analyzed liquid through the measuring volume , and the transport delay of the device.

The closest to the invention in technical essence and the achieved result is a device for measuring the density of liquids and gases, including a flow tank with an analyzed liquid, in which two piezo tubes, a differential pressure meter, a secondary device, an inert gas flow controller and two constant pneumatic resistance on the inert gas supply lines to the piezo tubes.

Inert gas from the flow regulator enters through pneumatic resistors, piezotubes into the analyzed liquid and sparges through it. The gas pressure in the piezo tubes is determined by the hydrostatic pressure of the liquid columns from its surface to the depth of immersion of the piezo tubes. The pressure difference in the tubes is measured by a differential pressure gauge with a pneumatic outlet, the value of which is linearly related to the density of the measured liquid and is recorded by a secondary device.

The disadvantages of the device are significant transport delays and delays.

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the dependence of the measurement results on the amount of inert gas sparging through the analyzed liquid, which increases with decreasing density measurement range, which reduces the accuracy of the measurement.

The aim of the invention is to expand the range and increase the accuracy of determination.

The drawing shows a functional diagram of the proposed device.

The device comprises a flow tank 1 with two overflow pipes 2 and 3, respectively located on opposite side walls of the tank 10, and a drain pipe 4, a tank 5 placed in the flow tank 1 and equipped with a overflow 6 and drain 7 pipes, a control unit 8 connected one output to the open shut-off valve 9 installed on the liquid supply line to the flow tank 1. and the other exit to the normally closed shut-off valve / 1 connected to the drain pipe 4 of the supply tank and the positive input to ifmanometer 11, the negative input of which is connected to the drain pipe 7 of the tank 5. and the output to the input of the secondary device 12.

The overflow pipe 2 of the flow tank 1 is located at the same level with the opposite overflow pipe b of the tank 5. The drain pipes 4 and 7 are located in the lower parts of the tanks 1 and 5 and are at the same level.

The control unit 8 is a pulse generator operating in conjunction with a decoder having eight outputs. The first five outputs of the decoders are connected by a common bus on which an output signal is present for a time TL

The last two outputs (seventh and eighth) are also combined by a common bus, on which an output signal is present during the time T3. The sixth output of the decoder is not involved, but serves to organize the time interval Ta.

The device operates as follows.

The container 5 is pre-filled with a reference liquid whose density corresponds to the beginning of the scale of the measured density range.

The controlled liquid enters the flow tank 1 during the time Ti necessary for its full renewal. The amount of the analyzed liquid is chosen so as to ensure overflow through the nozzles 2 and 3. This creates the necessary difference in liquid levels in the left and right parts of the tanks 1 during the time Ti.

After the elapsed time, Ti control

block 8 gives a signal to close the normally open valve 9, stopping the flow of the analyzed fluid into the flow tank 1. This leads to the fact that the level difference between the right and left

parts of the container 1 due to the free flow of liquid through the pipe 2 decreases to zero during the time T2. the flow through the tank 1 is stopped and the liquid levels in the tanks are aligned

1 and 5.

After the time T has elapsed, the control unit 8 issues a command to open the normally closed valve 10 and a signal is input to the positive input of the differential pressure gauge 11

pressure of the hydrostatic column of the analyzed liquid in the tank 1.

At the negative input of the differential pressure gauge receives the pressure signal of the hydrostatic column of the reference liquid,

The differential pressure gauge 11 measures its output signal to a value corresponding to the pressure difference AP. The pressure drop at the inlet of the differential pressure gauge 11 is determined by the formula

DR (/ g - / g) dN,

where p, rat are the densities of the controlled and reference liquids, respectively: g is the acceleration of gravity; K is the height of the liquid column in the tank x

1 and 5.

The output signal of the differential pressure gauge 11 is fed to the input of the secondary device 12, which records the results of the density measurement.

After the time Tz expires, the control unit 8 stops issuing a signal to the controlled valve 10, as a result of which the valve 10 closes, at the input of the differential pressure gauge 11 remains unchanged, the pressure drop

Other and, therefore, its output signal remains unchanged, which continues to be recorded by the secondary device 12 until the next measurement.

At the end of time T3, the cycle of work

system repeats.

Claims (1)

SUMMARY OF THE INVENTION A device for determining the density of liquids and gases, comprising a flow vessel, a differential pressure gauge, and a secondary device, characterized in that that, in order to expand the range and improve the accuracy of determination, it additionally contains a second tank with a variable and the drain pipes and the control unit, the flow tank additionally contains two overflow pipes located at different levels installed on opposite side walls of the tank, a drain pipe located below the overflow pipes, and two shut-off valves, the first of which is installed on the water supply line, and the second is on the drain pipe, while the second tank is placed in the cavity of the flow tank, the first 0 the output of the control unit is connected to the first shutoff valve, and the second to the second valve and the positive input of the differential meter, the negative input of which is connected to the drain pipe of the second tank, the lower overflow pipe of the flow tank is located on the same level with the overflow pipe of the second tank, and the drain pipes are located in the lower parts of the corresponding containers .and are installed on the same level.  liquids.