KR19980026018U - Automatic control device with bubble level clogging prevention function - Google Patents

Abstract

The present invention detects the degree of blockage of the sensing tube, and applies a high-pressure air to the sensing tube to prevent the blockage of the sensing tube, thereby improving the control ability of the bubble level meter. It is an object of the present invention to provide a control device, comprising: a pressure level regulator, a flowmeter for a flow rate set, a bubble level meter consisting of a sensing tube and a level converter, wherein the proximity of the flowmeter is detected so as to detect displacement of the float. A three-way valve connected in three directions of the photosensor, a prescribed air supply line provided with the flow meter, a high-pressure purge air supply line, and the sensing tube, and a control valve provided between the level converter and the sensing tube. And, when the sensing signal is applied from the photosensor, the three-way valve is applied to the sensing tube by the purge air And a controller for controlling the valve such that the breaking operation.

Description

Automatic control device with bubble level clogging prevention function

The present invention relates to a bubble level gauge that detects a value proportional to the level of the liquid to be measured. More specifically, it detects whether a sensing tube of the bubble level meter is blocked and automatically applies a high-pressure purge air when it is blocked. The present invention relates to an automatic control device having a bubble level meter clogging prevention function to prevent the sensing tube from being blocked.

Generally, a bubble level meter is a level meter widely used in process instrumentation and is mainly used in a place where an ultrasonic level meter cannot be used because the liquid of the level to be detected is ACID SOLUTION or FUME or steam.

Such a bubble level meter is equivalent to the level (height) × specific gravity × gravity acceleration of a liquid under measurement by inserting a sensing tube, which is a tube or pipe, such as TFELON, into a liquid to be measured and injecting a certain amount of air (air) at a certain pressure. The pressure (back pressure) to remain in the pipe is a value proportional to the level.

1 is a block diagram showing such a general bubble level, the operation is performed as follows.

The pressure regulator 11 supplies a prescribed pressure, and the inlet flow rate set part 12 operates so that the air supplied at the specified pressure from the pressure regulator 11 is supplied to the sensing tube 13 with a proper flow rate. A predetermined amount of air is supplied to the tank 14 containing the liquid to be measured 15 through the air sensing tube 13, and the level of the liquid to be measured 15 is measured as described above in the sensing tube 13. , Height) × specific gravity × back pressure corresponding to gravity acceleration. Then, the level converter 14 detects the back pressure of the sensing tube 13 and converts it into an electrical signal. Therefore, the level of the liquid under measurement 15 can be detected by checking the output signal of the level converter 14.

In addition, there may be a problem that the end of the sensing tube introduced into the liquid to be measured is clogged by a foreign substance contained in the solution. In the past, there is no means for detecting the problem, such that a bubble level gauge malfunctions due to clogging of the sensing tube. There was this.

In addition, when such a blockage occurs, conventionally, the air for flushing or the sensing tube is artificially cleaned, and thus level detection is not possible at the time of flush air or cleaning of the sensing tube. There was a problem of this deterioration, and in general, since the bubble level meter is used to measure the level of the acidic solution or the toxic solution, the worker was injured when the sensing tube was artificially cleaned.

The present invention is to solve the conventional problems as described above, the purpose is to detect the degree of blockage of the sensing tube, by applying a high pressure air to the sensing tube to prevent the blockage of the sensing tube and control the bubble level gauge It is to provide an automatic control device having a bubble level clogging prevention function that has an effect of improving the.

1 is a configuration diagram showing a general bubble level meter.

Figure 2 is a block diagram showing a bubble level meter having an automatic control device with a clogging prevention function according to the present invention.

3 is a block diagram illustrating an internal configuration of the controller shown in FIG. 2.

FIG. 4 is a timing diagram illustrating an operation state of the controller shown in FIG. 3.

* Description of the symbols for the main parts of the drawings *

21: Manual valve for air supply 22: Pressure regulator

23: Flowmeter for drawing flow rate 24: Photo sensor

25: 3-way valve 26; manual valve for purge air

27: control valve 28: level converter

29: sensing tube 30: controller

As a technical means for achieving the above object, the present invention is a bubble level meter consisting of a pressure regulator, a flow meter for the flow rate set, a sensing tube and a level converter, the displacement of the float (FLOAT) of the flow meter A photo sensor installed close to the detector, a prescribed air supply line provided with the prometer, a high-pressure purge air supply line, and a three-way valve connected in three directions of the sensing tube; and between the level converter and the sensing tube. The control valve is provided, and when the detection signal is applied from the photosensor, the three-way valve is characterized in that it comprises a controller for controlling the purge air is applied to the sensing tube and the control valve is shut off.

2 is a block diagram showing the automatic purging device for preventing clogging of the bubble level system according to the present invention, 21 is a manual valve installed in the supply pipe for supplying air, 22 is a passage supply through the developed manual valve 21 A pressure regulator for setting the pressure of the air to be a prescribed value, 23 is a flow rate set flow meter (FLOW-) for setting the amount of air introduced into the sensing tube popular air at the pressure prescribed by the pressure regulator 22 METER), 24 is a photo sensor installed close to the flowmeter 23 to detect the displacement of the FLOAT in the flowmeter 23, 25 is a three-way valve to the flowmeter 23 on one input side The type force side is connected to the purge air supply line to convert the output air in accordance with the control signal from the controller (30). And, 26 is a manual valve provided in the purge air supply line, 27 is a control valve of the normal off type is provided in the pipe connected to the level converter 28 to operate on / off according to the control signal of the controller 30, 28 is a level converter for converting the back pressure in the sensing tube 29 into an electrical signal, 29 is a sensing tube inserted into a tank containing the fluid to be measured, and 30 is a signal according to the output signal from the photosensor 24. The controller controls the three-way valve 25 and the control valve 27.

FIG. 3 is a block diagram showing the internal configuration of the controller 30 shown in FIG. 2, which is operated by an operator and provided from a push button 41 provided in a power supply (VCC) line and output from the photosensor 24. A contact switch 42 which is in conduction by a sensing signal, an or gate 43 connected to the other end of the push button 41 and the A contact switch 42, and the or gate 43 A sickle flip 44 for inverting an output signal of the SR flip flop 45 having an S input connected to an output of the ore gate 43 and an R input connected to an output of the sick gate 44; Timer 1 46 is set to a predetermined delay time connected to the output terminal (Q) of the SR flip-flop 45, and longer than the timer 1 (46) connected to the output terminal (Q) of the SR flip-flop 45 The timer 2 47 having the delay time, the output Q of the SR flip-flop 45 and the inverted output of the timer 2 47 are discussed. An AND gate 48 which is multiplied and applied to one input terminal of the or gate 43, an AND gate 49 which logically multiplies the output signal of the or gate 43 by the inverted output signal of the timer 1 46, and An AND gate 50 that logically multiplies the output signal of the or gate 43 and the inverted output signal of the timer 2 47, a base is connected to an output terminal of the AND gate 49, and the collector is a resistor R1. Transistor 51 connected to the DC power supply terminal (+) through, and the base is connected to the output terminal of the end gate 50 and the collector is connected to the DC power supply terminal (+) through the resistor (R2) (52), two auxiliary relays 53, 54 and two auxiliary relays 53, 54 provided between the emitter and (-) ends of the two transistors 51, 52, respectively. A contact switches 53-a and 54-a which are in a conducting state by switching operation by the operation of the A contact switch 53 -a) the electrical signal is supplied by the conduction to connect the purge air inlet side and the output side and the three-way valve 25, and the electrical contact is supplied by the conduction of the A contact switch (54-a) is cut off state Control valve 27, and a power distribution unit 57 for supplying a DC power supply (for example, DC 24V) and an AC power supply (for example, AC 110V) for the operation of each device.

FIG. 4 is a timing diagram showing the operation of each device shown in FIG.

Next, the operation of the present invention according to the above-described configuration will be described. First, a schematic operation of the blockage preventing device according to the present invention will be described with reference to FIG. 2, in which two manual valves 21 and 26 are developed to supply prescribed air and purge air.

Then, the air supplied through the manual valve 21 is adjusted to the pressure (for example, 1KG / ㎠) prescribed by the pressure regulator 22, the flow meter 23 is the air of the prescribed pressure sensing tube ( 29) Measure the flow rate applied to. Here, if the sensing tube 29 is blocked by foreign matter, depending on the degree of clogging, the amount of air flowing into the sensing tube 29 is reduced. Thus, the position of the float of the flow-meter 23 changes while being measured or written down on the flow-meter 23.

The photosensor 24 is installed close to the flow meter 23 and detects displacement of the prote. That is, when the prot comes to a predetermined position (when lower than the normal value), the photosensor 24 detects this and outputs a detection signal to the controller 30. The controller 30 applies an operation control signal to the three-way valve 25 and the jaw valve 27.

Thus, the three-way valve 25 shuts off the inlet connected to the flowmeter 23 and expands the inlet connected to the manual valve 26 for purge air supply, so that the pressure higher than the specified pressure (1KG / cm 2) , 7KG / cm 2) is supplied to the sensing tube 29. In addition, the control valve 27 is normally open, and is operated by an operation control signal applied from the controller 30 to open and close. Therefore, the level converter 28 is blocked from the sensing tube 29 side to prevent the level converter 28 from malfunctioning by the purge air.

By the above, a high-pressure purge air is applied to the sensing tube 29 having the clogging phenomenon so that foreign matters inserted into the sensing tube 29 can escape.

Next, the detailed operation of the controller 30 will be described with reference to FIGS. 3 and 4.

When the photosensor 24 shown in FIG. 2 detects the float displacement of the flow-meter 23 and outputs a high level detection signal as shown in FIG. 3, the A contact switch 42 operates so that the conduction state is established. do. As a result, a high level signal is output to the output of the or gate 43, whereby 1 is input to the S input terminal of the SR flip-flop 45, 0 is input to the R input terminal, and a high level signal is output to the output terminal Q. do.

In other words, the SR flip-flop 45 operates as a buffer. In addition, the output signal of the SR flip-flop 45 and the output signal of the timer 2 47 are logically multiplied by the AND gate 48 to be applied to the OR gate 43, whereby the AND gate 48 is set to timer 2. A low level signal is output from the point of time at which the high level signal is applied from the signal 47, that is, after the delay type set in the timer 2 47, and the or gate 43 causes the output signal of the photosensor 24 to be low level. Even if this happens, the high level output signal is held for a time equal to the delay time set in the timer 2 47 from the high level time of the photosensor 24.

The timer 1 46 and the timer 2 47 output the high level signal after the delay type set from the time point at which the high level signal is output from the SR flip-flop 45, and the delay time of the timer 1 46 is increased. It is set shorter than the delay time of timer 2 (47). This is a time difference for the pressure in the pipe to be stabilized when the high pressure purge air supplied to the sensing tube 29 is discharged and the air of the prescribed pressure is supplied again.

Accordingly, the high level signal is output from the timer 1 46 after the time T1 passes after the high level signal is applied from the photosensor 24 as shown in ⓔ in FIG. 4. Since the inverted signal and the output signal of the or gate 43 are logically multiplied and applied to the transistor 51, the transistor 51 delays the timer 1 46 from the time when the photosensor 24 outputs a high level signal. It becomes a conduction state for time, and power is applied to the auxiliary relay 53, and it operates, and the contact A 53-a of the auxiliary relay 53 turns on. Accordingly, an electric signal is applied to the three-way valve 25 during the set time T1 of the timer 1, and the three-way valve 25 operates to supply the purge air to the sensing tube 29. That is, a purge air of a pressure of 7KG / cm 2 is supplied to the sensing tube 29 during the time T1.

The timer 2 47 operates while the high level signal is output from the SR flip-flop 45 to output the high level signal after a time T2 longer than the delay time T1. Since the signal obtained by inverting the output signal of 47 and the output signal of the or gate 43 are logically multiplied by the AND gate 50 and applied to the transistor 52, the transistor 52 is connected to the photosensor 24. From the time at which the high level signal is outputted, the state of conduction is maintained for the delay time by the timer 2 47, and the auxiliary relay 54 is operated. Accordingly, the contact A-54-a of the auxiliary relay 54 is turned on for the time T2 to apply an electric signal to the control valve 27, and thus the control valve 27 operates to operate the three-way valve 25. Is turned off for a time period T2 longer than the time period T1. As a result, the operation of the level converter 28 is interrupted to prevent malfunction.

As such, the controller 30 controls the three-way valve 25 to supply the purge air to the sensing tube 29 for a predetermined time T1 from the time when the photosensor 24 detects the prot, The control valve 27 is turned off for a long time T2 to prevent the level converter 28 from malfunctioning.

The controller 30 operates in the same manner as when the photosensor 24 detects the float even when the push button 41 provided at the one input terminal of the or gate 43 is turned on. Therefore, the worker may arbitrarily remove foreign substances introduced into the sensing tube 29.

As such, the present invention can detect the degree of blockage of the sensing tube in a bubble level meter, and when the sensing tube is blocked for a predetermined standard or more, a high pressure purge air higher than a predetermined pressure is applied to the sensing tube for a predetermined time. Is prevented from clogging, and also blocks the operation of the level converter while the purge air is applied, thereby preventing the bubble level gauge from malfunctioning, thereby improving the accuracy of the bubble level meter. .

Claims (2)

In the bubble level meter consisting of a pressure regulator, a flow meter for the flow rate set, a sensing tube and a level converter, A photosensor which is installed in close proximity to detect the displacement of the float of the flow meter; A three-way valve connected to three directions of the prescribed air supply line and the high-pressure purge air supply line and the sensing tube provided with the flow meter, A control valve provided between the level converter and the sensing tube; The detection signal is applied from the photosensor, and the three-way valve is a purge air automatic purging device for preventing clogged level gauge, characterized in that it comprises a controller for controlling the control valve to shut off operation. According to claim 1, The controller A push button which is operated by an operator and is provided at a high level signal applying end, A contact switch which is turned on when a detection signal is output from the photosensor, and applies a high level signal, and the push button and A contact switch and the first end. An OR gate having three inputs connected to an output terminal of the gate, a sick gate for inverting the output signal of the OR gate, and an SR flip having an output terminal of the OR gate connected to an S input terminal and an output terminal of the sick gate connected to an R input terminal A flop, a timer 1 connected to the output of the SR flip-flop and set to a delay time of T1, a timer 2 connected to the output of the SR flip-flop and set a delay type of T2, and the SR flip-flop A first end gate and an output of the output signal and the inverted output signal of the timer 2 to the or gate, and an output of the or gate A second and gate for ANDing the call and the inverted output signal of the timer 1, a third and gate for ANDing the output signal of the or gate and the inverted output signal of the timer 2, and a base connection to an output terminal of the second and gate. A first transistor to which the collector is powered through a resistor, a base connected to an output terminal of the third and gate, a second transistor to which the collector is powered through a resistor, and an emitter and ground of the first transistor. The first auxiliary relay provided between the second auxiliary relay provided between the emitter and the ground of the second transistor and the first auxiliary relay are brought into a conductive state to apply an electrical signal to the control valve. A second A contact for applying an electrical signal to the three-way valve is brought into a conductive state by the operation of the first A contact switch and the second auxiliary relay Group predation level to clogging preventing automatic purge device which is characterized in that a switch.