SU1302171A1 - Gas analysis system - Google Patents

Abstract

The invention relates to a gas analysis system, can be used in chemical industry and allows to increase the reliability and accuracy of measurement of the system. The system comprises a control unit 1 associated with switches 16 and 17 connected respectively to power jet amplifiers 14 and 15 and pressure controller 18 with a setting device 19. The outputs of amplifiers 14 and 15 are connected to pneumatic interconnections 10, 11, 12 and 13. In the thermostatically controlled housing 5, check valves 20 and 21 and a locking device are installed, in the form of chambers 22 and 23, with pairs of nozzles 24 and 25, 26 and 27 installed coaxially towards each other. The latter are located at a distance from each other. other, in which the impulse of jet power from the exit of the nozzles 25 and 27 changes pressure at the inlet of the nozzles 24 and 26 to a value equal to the value of the pressure of the setting device 19. 1 sludge. W (L and

Description

The invention relates to the field of gas analysis, and more specifically to automatic gas analysis systems of multipoint control of the chemical composition of hot vapor-gas mixtures, and may find application in the control of ammonia, sulfur dioxide, nitrogen oxides, carbon monoxide, methane and other gases, for example, chemical plants, in the production of mineral fertilizers.

The purpose of the invention is to increase to. reliability of the system with a simultaneous increase in measurement accuracy.

The drawing shows a block diagram of a gas analytical system (for two control points).

The system contains a control unit 1 of line 2 and 3 of the supply of analyzed vapor-gas mixtures, line 4 of compressed air supply, a thermostatically controlled housing 5 with air inlets 6 and 7 located in it and a diluent 8 connected to a gas analyzer 9. The system also contains air throttles 10-13, jet amplifiers 14 and 15 of power, switches 16 and 17, pressure regulator 18 with pressure setting device 19. In the thermostatically controlled housing 5, check valves 20 and 21 and shut-off devices are installed, made in the form of chambers 22 and 23 with the pairs of nozzles 24-27 installed in them coaxially facing each other, which are spaced apart from each other. wherein the impulse of the jet force from the exit of the nozzles 25 and 27 changes the pressure at the inlet of the nozzles 2 and 26 to a value equal to the distance value of the pressure setting device 19.

The gas analytical system operates as follows.

The distance between the nozzles 24 and 25 is checked and, if necessary, adjusted; a pressure gauge is connected to the first input of the regulator 18 for this. The maximum pressure is established at the inlet of the throttles 6 and the minimum flow rate through the diluent 8, after which the distance between the nozzles 24 and 25 is changed until the pressure on the manometer is less than the minimum pressure value of the pressure setting device 19. In this position, the nozzles 24 and 25 are mechanically fixed, for example, by means of locking nuts, which are screwed onto the nozzle body. Similarly, the distance between the nozzles is checked and adjusted.

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not supported 100-200 C, and

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26 and 27. In order to avoid condensation in case 5, for example, using a thermostat (not shown)

the temperature is in the range of throttles 6 and 7, diluent B, non-return valves 20 and 21, chambers 22 and 23 of the nozzles 24-27 acquire the same temperature. The hot gas vapor mixture is analyzed along lines 2 and 3, passes throttles 6 and 7, nozzles 24 and 26, enters chambers 22 and 23 and is discharged.

For sampling from line 2 in the first (shown in the drawing) position of switches 16 and 17 in accordance with the signal of control unit 1, the input of switch 16 is connected to its first output j and the first output of switch 17 is atmospheric. The flow of hot analyzed gas mixture from line 2, choke 6 passes from the outlet of which the initial stream is divided into two streams. The first stream passes the check valve 20 and enters the diluent. The part of this stream, which is no more than 1–5% of the main stream (in practice,

5-20 l / h), through the choke 13 discharge- I

vyatsya. The second stream from the outlet of the throttles 6 is directed to the nozzle 24.

The pressure from the output of the pressure setting device 1 9 goes to the second input of the regulator 18, to the first input of which pressure comes from the output of the o6ipaTHo valve 20 ". The signal from the output of the regulator 18 through the switch 16 enters the input of the jet amplifier 14, from which the signal the error, enhanced by the flow, in the form of air flow enters the inlet of the nozzle 25. The exit of the last air stream is directed towards the jet of the analyzed gas-vapor mixture leaving the nozzle 24, and then the streams mixed in the chamber 22 flow into the discharge. The impulse of the air jet force in the braking section, loses its energy, changes the impulse of the force of the jet of the analyzed mixture coming towards, resulting in a change in pressure at the inlet of the nozzle 24 and, accordingly, at the inlet of the diluent 8. The regulator 18 changes the value impulse force of air jet, thereby changing the magnitude of impulse force of the jet of the analyzed mixture to a value at which the pressure at the first inlet of the regulator

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18 becomes equal to the setting pressure of the knob 19 to its second inlet, thereby stabilizing the inlet pressure of the diluent 8. At the same time, the mixture being analyzed from line 3 passes through the throttle 7, the nozzle 26, the chamber 23 and enters the discharge. The first input of the amplifier 15 is connected via a switch 17 to a reset, and therefore the amplifier 15 does not create an air jet in the nozzle 27, resulting in a pressure at the inlet of the nozzle 26 less than the minimum pressure of the pressure setting device 19 and, accordingly, less than the pressure at the inlet nozzle 24. Since the pressure at the inlet of the check valve 21 is greater than the pressure at its outlet, the check valve 21 is closed. Thus, in the first position of the switches

16 and 17, the analyzed gas mixture from line 2 at a stabilized pressure enters the diluent 8, and the gas analyzer 9 shows the concentration of the component to be determined in the mixture. The air flow from line 4 passes the throttle 11, the nozzle 27 and is discharged from the chamber 23. This air flow prevents the vapor-gas jet from the nozzle 26 through the nozzle

27 to the amplifier 15 and the output of the last system.

Sampling is switched from line 2 to line 3 as follows. In accordance with the signal of the control unit 1, the switches 16 and

17 is shifted to a second position, in which the first output of the switch 16 is connected to the atmosphere, and the input of the switch 17 is connected to the output connected to the amplifier 15. The flow of the heated mixture from line 3 passes through the throttle 7 and is directed to the nozzle 26. A stabilized pressure is maintained at the inlet of the nozzle 26 and, respectively, diluent B in the same way that the switches 16 and 17 were maintained at the first position of the nozzle 24 in the first position. The gas mixture under analysis at stabilized pressure enters the diluent

8, and the gas analyzer 9 indicates the concentration of the component to be detected in the mixture coming through line 3. The part of this flow is thrown off through the choke 13. The air flow from line 4 passes the throttle 10, the nozzle 25 and is discharged from the chamber 22. This air flow prevents air from entering

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roga jet from the nozzle 24 through the nozzle 25 into the amplifier 14 and the output of the last of the system,

In the first and second positions of the switches 16 and 17, the flow of compressed air from line 4 passes through the throttle 12, part of the pipeline connecting the regulator 18 to the diluent 8, and through the throttle 13 is reset. This air flow prevents the vapor-gas mixture from entering the regulator 18, which would cause the resins to settle on its elements and disable it.

Claims (1)

Invention Formula A gas analyzing system containing a diffusion diluent placed in a thermostated housing and a pneumothrottle and a locking device installed in each supply line of the analyzed mixture, a gas analyzer connected to the outlet of the diluent, a control unit for analyzing the sequence of operations of the switches in each output channel and pneumatic throttle mounted in the supply line of the compressed air and in the discharge line, which is different from the fact that, in order to increase the reliability of the system while simultaneously increasing the accuracy, It contains check valves placed in a thermostated housing, a gas pressure regulator at the diluent inlet and a booster amplifiers, the control inputs of which are connected to the compressed air supply line, and the shutoff devices placed in the thermostatted housing are made in the form of chambers with coaxially mounted valves. towards each other by nozzles, the inputs of the first of which are connected through pneumatic throttles to the corresponding supply line of the analyzed mixture, each of which, after the pneumodrottle, is connected through the corresponding The return valve is connected to the diluent inlet, and the second secondary ports are connected to the output of the jet amplifiers and to the compressed air supply line. The output of the pressure regulator is connected via the corresponding switch of the control unit to the inputs of the jet amplifiers, and the reset line is connected to the outputs of non-return valves and to compressed air lines to the diluent.