SU1275217A1 - Liquid metering device - Google Patents

Abstract

The invention relates to instrumentation engineering and allows improving the accuracy and speed of dosing. Measuring vessel 8 is made of two sections with an overflow opening 25 connecting them, through which the liquid enters the drainage cup 23. The liquid presence sensor 28 generates a signal when the measuring vessel is completely filled, which turns off the solenoid of the filling valve.

Description

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tc Residual fluids flow out through the drainage pipe 26. The dose volume is determined by the height of the liquid column from the overflow hole 25 to the lower meniscus position on the axis 29 of the photosensor 27. Additional channels 5 and 1 17 6 divide the shock wave into two parts to avoid false triggering of the drain valve 3. The ratio of the flow areas of the throttling porridge tO and channels 5 and 6 is selected in the range of 0.2-0.05. 5 il.

The invention relates to instrumentation and can be used for high-performance automatic dosing of liquids, including chemically active,

The purpose of the invention is improving the accuracy and speed of dosing.

Fig, 1 shows the dispenser, a general view; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a section BB in FIG. one; in fig. 4 is a schematic diagram of the automatic control of the dispenser of FIG. 5; dependence of the accuracy of the dispenser a on the ratio of the flow areas of the channels in the valve block.

The liquid dispenser contains a valve block 1, in which filling 2 and 3 cavities of corresponding membrane valves with seats A, a stepped main channel 5 are filled, on which valves and section 6 between the valves are placed: ow: falling from the axis of the inlet 7 of the measuring vessel 8 , the drainage channel 9 with the throttle channel 10, made in the plug 11, the inlet 12 and the output 13 of the cough. The Yu1apanov block is equipped with elastic diaphragms 14 with washers 15j fixed to a nickname (for example, by vulcanization) on the opposite side of valve seat 4, electromagnets 16, springs 17 placed in channels of cores 18, inlet fitting 19), outlet fitting 20 and seal 21, plugs 22. Merny vessel with its nozzle 7 is connected to section 6 of channel 5, and its upper part is made in two sections, the upper section being a drainage cup 23 connected to the lower section 24 by an overflow orifice 25 and equipped with drainage pipe 26.

The ratio between the areas of the overflow sections 25 and the drainage pipe 26 q 1.

The measuring vessel is provided with a low level sensor 27, the position of which can be changed to change the dose, and a liquid presence sensor 28, such as photoelectric, optical axes 29 and 30, which are perpendicular to the axis of the vessel filled with working fluid 31 with meniscus 32 at the boundary with air, i.e. placed at the level of the overflow hole.

The sensors 27 and 28 of the electrical circuits 33 are connected to the automatic control unit 34, and the delay unit 35 is connected between the block 34 and the drain valve 1.

The device in the automatic control mode works as follows.

To fill the measuring vessel 7 with the working fluid from the remote control of the automatic control unit 34, the electromagnet 16 of the filling valve is switched on (FIG. 3), which overcomes the force of the spring 17, attracts the washer 15. with the diaphragm 14 to the core 18, while the working fluid under some excess pressure from the outside through the pipeline (not shown) enters the fitting 19 and further, through the channel 12, the gap between the valve seat 4 and the diaphragm 14 into the filling cavity 2 and further, through the channel 5 and section 6 into the vessel 7. The column of liquid rises by measure After filling the vessel, through the overflow 25 begins to flow into the drainage cup 23. Due to the fact that the overflow section 27 is larger than the output section of the drainage pipe 26, the liquid begins to fill the drainage cup 23. The signal from the liquid presence sensor 28 indicates full filling The vessel enters the control device 34, which shuts off the solenoid 16 of the filling valve, after which, under the influence of the spring 17, the diaphragm 14 is pressed against the valve seat 4, stopping the flow of fluid into the measuring vessel. The residual liquid from the drainage cup-23. through the drainage pipe 26 expire in the drainage tank (not shown). Air bubbles passing from a liquid 15 in the filling and drain cavities 2 and 3, respectively, through the drain valve 8, the throttling valve lS and the upper part of the main channel -5 penetrate into the measuring vessel, 20 and from there through the overflow 27 are removed to atmosphere, which ensures the constancy of the dosage volume and the accuracy of its reproduction. The surface of the liquid at the overflow section 27 occupies 25 strictly constant position and therefore is the initial (zero) reference point of the dosed volume of liquid emanating from the measuring volume. After the electromagnet is turned off 30 16 and the technological pause is carried out from the delay unit 35 and is sufficient to drain the liquid from

the drainage cup 23, the electromagnet 16 is automatically switched on (Fig. 2), attracting the diaphragm 14 with the washer 15 to the core 18.

The working fluid from the measuring vessel through the upper part of the channel 5, the cavity 3 of the drain valve, the gap between the diaphragm 14 and the valve seat 4, the channel 13 and the fitting 20 is poured into the receiving tank. The outflow of fluid continues until it crosses the optical axis 29 of the photosensor 5, 27, which is a signal to turn off the electromagnet 16, then under the influence of the spring 17, the diaphragm 14 is pressed against the valve seat 4, stopping the outflow of liquid from the measuring valve vessel. Thus, the dose volume is determined by the height of the liquid column from the overflow 25 to the lower position of the meniscus on the axis 29 of the photosensor 27.55

In order to prevent the drain valve from the pressure wave, which occurs when the filling valve 2 is closed and propagates through channel 8 and acts on the drain valve 3, additional channels are made in the valve block 1 (1X 5 and 6) to divide the shock wave into two parts and the bypass of one of them directly into the measuring vessel through channels 5 and 6, and the other through channels 8, in which cork 11 is installed with throttle channel 10, the ratio of flow areas of throttle channel 10 rear and channels 5 and 6 8c are equal to O, 2-0.05. Figure 5 shows an experimental relationship between the frequency (probability n) of the false positives of the drain valve 3 and the value of cf

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LL devices of this type is the optimal value. (|) lies in the range of qi 0,2-0,05.

Claims (1)

Invention Formula A liquid dispenser containing a measuring vessel with a level sensor mounted on it, the inlet pipe of the measuring vessel is connected to the main channel between the diaphragm valves located on the last filling and drain valve whose electromagnets and level sensor are connected to a control device characterized in that in order to improve the accuracy and speed of dosing, a sensor for the presence of a liquid, a throttle channel, a delay unit, the upper part of the measuring vessel are made in a height of two sections. with constant pereliv-; A bore hole connecting the sections at the level of which a liquid presence sensor is located, and in the lower part of the upper section a drain pipe is made, the cross section of which is smaller than the cross section of the overflow hole, the solenoid of the filling valve is connected through the control device to the liquid presence sensor, and the solenoid drain valve the delay unit and the control unit — with a level sensor; the section of the main channel between the filling and drain valves is aligned coaxially with the inlet of the measuring vessel, and the upper point cavity the discharge valve through the throttle channel is connected to said the main channel section, the cross section of the throttle channel and the main channel being selected from the ratio Sj., / S 1275217 0.2-0.05, where 8dr and S) are the cross-sectional areas of the throttle and main channels, respectively. one /- yeri j Jj