SU1530920A1 - Registering and metering arrangement - Google Patents

Abstract

The invention relates to a technique for automatically measuring the flow rate of a fluid, a predetermined volume of a fluid, and controlling its flow rate. The aim of the invention is to expand the functionality of the device by ensuring its continuous operation. In the initial state, the cylindrical vessels 1 and 6 are empty, at the output of the level gauge 4 the signal is close to zero, and at the output of the null organ 16 is a logical zero. This logical zero through the cells 23 and 28 will open the valves 3 and 12. The liquid through the valve 3 will flow into the cylindrical vessel 1. After filling it, the signal from the level gauge 4 is comparable to the signal of the setpoint 20, the logical unit at the output of the zero-body 16, in counter 34, unit subtraction will occur, valves 3 and 12 will close, and valve 10 will open. The liquid to be dosed will start to flow into the cylindrical vessel 6. At the exit of the null organ 17, a logical unit occurs, which opens the valve 2 through the cell 32. The liquid being dosed from the cylindrical vessel 1 begins to flow to the consumer. The regulator 18 through the converter 22 stabilizes the flow rate by changing the flow area at the control valve. The counting device operates continuously, the cycles are repeated one by one, the number of cycles is set by the pulse counter 34. 2 Il.

Description

The invention relates to a technique for automatic measurement of a fluid flow rate, a given volume of fluid, and a registration of its flow rate,

The purpose of the invention is to expand the functionality of the device by ensuring its continuous operation.

FIG. 1 is a block diagram of the device; in fig. 2 - diagrams for example HHII in time.

The device contains the first cylindrical vessel 1, the first valves at flow 2 and supply 3 liquid, the first level gauge 4, control valve 5, the second cylindrical vessel 6, the second valves at flow 7 and flow 8 liquid, the second level gauge 9, the first 10 and second II valves for supplying compressed Air, first 12 and second 13 valves for discharge of compressed air, switch, differentiation unit 15, first 16 and second 17 null-ganns, regulator 18, first 19, second 20 and third 21 setters, converter 22, first 23, second 24, third 25, fourth 26 and fifth of 27 and NOT, the first 28, the second 29, the third 30, the fourth 31 and the fifth 32 cells And the trigger 33 and 34 counts with a dial.

FIG. 2 the following notation is accepted: 35 - voltage plots on the level gauge 4; 36 — stress diagrams on level gauge 9; 37 are stress plots on the setpoint 20; 38 are plots on the setpoint 21; (O - t,) (t - t) is the time for filling the cylindrical vessel 1; (t, - t (t - t) is the time for filling ts11L1 of the Shdrichesky vessel 6; (t, - tj) (r-5- t,) is the time of the discharging from the 1-cylindrical vessel 1; (t; jt) (tT-tj) - the discharge time from the pilot vessel 6; (t - t) the waiting time (no drain and filling) of the cylindrical soda 1; (ti -t) (t - t-,) is the waiting time (no drain and filling) of the cylindrical vessel 6.

Valves 2, 3, 7, 8, 10-13 are identical, shut-off valves and in the absence of a control signal from them are fully open. The control valve 5 changes the flow area depending on the value of the control signal.

Comrade 14 consists of two relays, kg1T () rymi controls the trigger

33. The latter turns on the relay of switch 14 in turn. The relay contacts of the switch 14 connect the input signal from the level gauges 4 and 9 to the null organs 16, 17 and to the differentiation unit 15 in turn. If the level gauge 4 is connected to the null organ 16, then the level gauge is connected to the null organ 17 9.

The normally closed contacts of the switch 14 connect the inputs of the helixes 23 and 24 to the common potential, thereby presenting lo on these inputs; physical unit. When one of the relays of the switch 14 is turned on, the corresponding input of the cell NOT is disconnected from the common potential and connected to the output of the zero-body 16.

Differentiation unit 15 calculates the first derivative of the level value from level gauges 4 and 9, and since the section along the height of cylindrical vessels 1 and 6 is constant and the same, the output signal from differentiation unit 15 is proportional to the flow rate.

The null body 17 is a threshold element, which forms a logical unit at the output only if the input signal is equal or the input signal is greater than the task.

The null organ 18 is a threshold element that forms a logical unit at the output when the input signal is equal to or greater than the reference.

The process of starting the metering device begins with determining the setting values of the setpoint and setting them. The setpoint value for the setting device 19 is determined by the magnitude of the required flow rate and is determined from the process procedure regulation.

The setpoint settings of the pulse counter 34 and the dial 20 are determined by the formula

Q - 2 nq ,.

where Q is the required dose value, takes into account the short-term regulation;

n is a positive integer

more than 0, the pulse counter 34 is set to 34;

q is the reference value set on the setting device 20, 0.7V q: 0.03V (based on the sensitivity of the level gauge);

V is the volume of the cylindrical vessel I or 6.

The setpoint value for the setter 21 is selected as minimum, it can be from 0.1V to 0.001V. After setting the setpoint values, the system starts up.

The operation algorithm of the metering device is as follows.

The output of the zero-organ 16 is connected to the output of the level gauge 4, the output from the zero of the organ) 6 - to the input cell NO 23, the valve 3 is open at the flow and the valve 12 to release compressed air. The filling of the cylindrical vessel 1 begins (Fig. 2, part of the plot 35 on the time interval O - t). At the same time, the output of the level-meter 9 is connected to the null organ 16 and the differentiation unit 15,

When the signal from the level gauge 4 is equal to the signal from the setting device 20, the valves 3 and 12 are closed and the valve 10 is uncoupled, and the hydraulic power supply in the cylindrical vessel 1 is performed.

The device works as follows

In the initial state, cylindrical vessels I and 6 are empty. When the metering device is turned on, the trigger 33 occupies its initial steady state, supplies a high potential to the AND 31 cell, connects the input of the zero body 16 to the sensor of the level meter 4, the inputs of the zero body 17 and the differentiation unit 15 - to the output of the level meter 9 and connects the output. a zero-body 16 with a NOT 23 cell with the help of switch 14. Since cylindrical vessel 1 is empty, and the signal at the output of level gauge 4 is close to zero, then at the output of zero-body 16 there is a logical zero, which through cells 23 and 28 opens valves 3 and 12. Pulse counter 34 is a single-shot that subtracts pulses from a zero-input 16 (from the serial input) from the task, set. poured at its second entrance to the parallel code.

At the output of the 34 impulses counter with the setting unit, a logical unit always exists when its set reference exceeds the number of counted pulses and the logical unit disappears only when they are equal. When the valve 3 is opened, the liquid is metered into the cylindrical vessel I (plot 35, section O - t).

Since the signal at the output of the level sensor 9 is close to zero and does not change, the zero signal is present at the output of differentiation unit 15. Consequently, the regulator 18 opens the control valve 5 through the converter unit 22. The dosing fluid is not supplied to the consumer, since the valves 2 and 7 are closed.

When the fluid detects a cylindrical vessel 1 and the signal from the level gauge 4 is compared with the signal of the setting device 20, a logical unit is generated at the output of the zero-body 16. This logical unit, through cell 30, flips trigger 33 to another steady state, and it switches the switch 14. A gauge 9 is connected to the null organ 6. There is a subtraction in the unit 34, the valves 3 and 12 are closed and the valve 10 is opened (dot A plot 35). The output signal of the zero-body 16 through the cells 24. and 29 opens valves 8 and 13. The dispensed fluid enters the cypindric vessel 6 (plot 35,

t, -tJ.

The inputs of the zero-organ J7 and differentiation unit 15 are connected to the level gauge 4. At the output of the zero-organ 17, a logical unit occurs, which opens the valve 2 through the cell 32. The liquid is metered from the cylindrical vessel J begins to flow to the consumer. Since the output signal at the level gauge 4 changes and the differentiation unit 15 outputs a signal, the regulator 18, through the converter 22, begins to stabilize it by changing the flow area of the control valve 5.

When the liquid to be dosed fills cylindrical vessel 6 (point B of plot 36 and the signal from level gauge 9 is compared with unit 20, a logical unit occurs at the output of the zero organ 16. This logical unit passes through cell 30 under the condition of emptying cylindrical vessel 1, m. that is, the appearance of a logical zero at the output of the null organ 17.

Logical unit zero-body 16 closes valves 8 and 13 and opens valve I without waiting for the transition

trigger 33 to another state. In this situation, only the cylindrical vessel 2 is emptied (plot 36, section tj tj), but there is no filling, as cylindrical vessel 6 is filled, and vessel 1 is not emptied (point 6 of plot 36).

The proposed dose metering device works continuously and the nickels repeat one after the other (the number of cycles is set by the pulse counter of 34 pulses). The application of the proposed device allows to expand the range of the measured volume of liquid and improve the accuracy of flow measurement.

Claims (1)

Invention Formula A metering device comprising a cylindrical vessel communicated with valves on the flow and supply of fluid and a level gauge, characterized in that, with a functional area, it is equipped with a second cylindrical vessel communicated with the second valves on the flow and supply of fluid and the second a level gauge, as well as a switch, a diLerence unit, two zero-organs, a controller, three setters, a converter, five NOT cells, five And cells, a trigger and a pulse counter with a setting unit, and A cylindrical vessel is provided with valves for supplying and discharging compressed air, the level of the switches and the skull of the switch is connected to one of the inputs of the first and second zero organs, the organs and the input of the differentiation unit, the output of which is through the regulator whose second input is connected to the first unit, and converter with & dinen with control valve, connected by another input to valves at flow both cylindrical vessels, the second inputs of the zero-organs are connected respectively to the second and third control points, the outputs of the first zero-organ directly, and the second through the fifth the cell is NOT connected to the inputs of the third And cell, the outputs of which are connected to the counting input of the trigger, the separate outputs of which are connected to the control inputs of the switch and the first inputs of the fourth and fifth cells of And, respectively, the second inputs of which are connected to the output of the second null organ, and the outputs - to the control inputs of valves on the flow of cylindrical vessels, the output of the first null organ is connected to the input of the pulse counter with the setpoint device and through the switch - with the inputs of the first and second elements are NOT, the output of the first element is NOT connect not with the second input of the first element And, the first input of which is connected to the output of the pulse counter with the setting device, and the output to the integrated control inputs of the valve in the flow and a valve for discharge of compressed air of the first cylindrical vessel, and through the third cell NOT with the control inlet of the valve for supplying compressed air of the first cylindrical vessel, the output of the second cell is NOT connected to the first inlet of the second cell And, the first inlet of which is connected to one of the outlets trigger and output with combined control inputs a supply valve and a valve for discharge of compressed air, and through a fourth cell NOT with a control input of a valve for supplying compressed air of the second cylindrical vessel.