Anti-breakdown control method for water seal in water seal check valve of wet dust removal system

Abstract

The invention relates to an anti-breakdown control method for a water seal in a water seal check valve of a wet dust removal system. The method comprises the following steps that firstly, a water seal check valve state position detection device is designed and installed, secondly, a water seal check valve detection instrument is designed and installed, and thirdly, air supply control is conducted on a communicating pipeline between a three-way valve and the water seal check valve. And fourthly, water replenishing of the water seal check valve is controlled. According to the technical scheme, the anti-breakdown control method for the water seal in the water seal check valve of the wet dust removal system is provided, gas in a gas holder is prevented from flowing backwards, and major safety accidents are avoided.

Description

Technical Field

[0001] The invention relates to a control method, in particular to a water seal anti-breakdown control method in a water seal check valve of a wet dust removal system, and belongs to the technical field of coal gas recovery in the metallurgical industry. Background Art

[0002] The converter wet dust removal system is a dust removal system currently used by most domestic and international steel mills. It has the advantages of safety, reliability and simple system. The high-temperature flue gas generated during the converter iron addition and blowing process is cooled to about 1,000°C through the converter skirt hood, straight smoke hood, corner smoke hood and annular seam. The initially cooled flue gas is sprayed with water through the primary dust collector spray tower to cool and remove dust, and then the water in the flue gas is removed through the dehydration tower. Qualified coal gas (CO content greater than 35%, 02 content less than 1%) is switched through the three-way valve and transported to the gas holder through the water seal check valve and V-type valve. Unqualified flue gas passes through the chimney and is released after ignition and combustion. The water seal check valve is composed of a drum-shaped cylinder filled with a certain water level and a fan-shaped rotary cover that can rotate in it. When the converter flue gas is released, the rotary cover is located above the water seal valve, cutting off the passage to the gas phase to prevent the gas in the gas holder from flowing back or the released flue gas from invading the gas holder. When the gas is recovered, the rotary cover is located on the side of the water seal valve. At this time, it is in a straight-through state, and the recovered gas can directly enter the gas holder. During the converter production, the water seal check valve is the only safety barrier to block the on-site dust removal air duct and the gas holder when the gas is not recovered. The safety and effectiveness of the water seal check valve is the top priority to ensure safe converter steelmaking. A connecting pipe is installed between the converter three-way valve and the water seal check valve. In order to prevent air and carbon monoxide that does not reach the recovery concentration from entering the connecting pipe between the three-way valve and the water seal check valve through the gap between the valve plates of the three-way valve "recovery position" during the interval between furnaces and the early stage of converter blowing, a safety nitrogen is installed on the connecting pipe between the three-way valve and the water seal check valve. By filling nitrogen into this connecting pipe, a positive pressure state is ensured inside the connecting pipe during the interval between furnaces and the early stage of converter blowing. At present, the inflation control method for safety nitrogen is that when the pressure in the connecting pipe is greater than the set value SP1, the safety nitrogen inflation control cut-off valve is closed and inflation is stopped; because the sealing of the connecting pipe is not tight, when the pressure in the connecting pipe gradually decreases and the pressure is less than the set value SP2, the safety nitrogen inflation control cut-off valve is opened to inflate the connecting pipe, and the inflation is repeated continuously and uninterruptedly. In actual use, this method can ensure that the connecting pipe is always filled with inert gas and can solve the existing problems. However, this method also brings inevitable safety problems, such as puncturing the water seal of the water seal check valve.When one of the components such as the intelligent pressure transmitter, solenoid valve, gas source pipeline, relay, PLC, and shut-off valve core used to control the automatic opening and closing of the security nitrogen shut-off valve fails, the shut-off valve may fail to close according to the control mode when the connected pipeline pressure setting value is greater than SP1. This problem will directly cause the security nitrogen to be continuously inflated until the pressure in the connected pipeline between the three-way valve and the water seal check valve is greater than the maximum pressure that the water seal inside the water seal check valve can withstand, and the water seal will be punctured. The consequence is that the gas tank and the three-way valve are in a connected state, and gas backflows, posing a great safety hazard to on-site personnel. As for how to avoid the failure of security nitrogen control due to control component failure, resulting in the puncture of the water seal of the water seal check valve, by consulting relevant information, no specific control measures were found at home and abroad. The present invention will have a specific control method to prevent the puncture of the water seal of the water seal check valve. Summary of the invention

[0003] The present invention is aimed at the problems existing in the prior art and provides a method for controlling the water seal inside a water seal check valve of a wet dust removal system to prevent breakdown. The technical scheme provides a method for controlling the water seal inside a water seal check valve of a wet dust removal system to prevent gas backflow from a gas tank and avoid the occurrence of major safety accidents.

[0004] In order to achieve the above object, the technical solution of the present invention is as follows: a method for controlling the water seal in a water seal check valve of a wet dust removal system to prevent breakdown, the method comprising the following steps:

[0005] The first step is to design and install a water seal check valve status position detection device.

[0006] The second step is to design and install the water seal check valve detection instrument.

[0007] Step 3: Control the air supply in the connecting pipeline between the three-way valve and the water seal check valve;

[0008] Step 4: Control the water supply to the water seal check valve.

[0009] Among them, in the first step, the water seal check valve valve state position detection device includes a first bracket 1, an inductive proximity switch 2, a circular hoop 3, a first fixing bolt 4, a second fixing bolt 7, a rocker rod 5, a second bracket 6 and a water seal check valve shaft 8, wherein the circular hoop 3 is sleeved on the water seal check valve shaft 8, and the first fixing bolt 4 and the second fixing bolt 7 are installed on the circular hoop, the circular hoop 3 is connected to the rocker rod 5, and the rocker rod 5 is connected to the arc-shaped metal sensor sheet 10, the first bracket 1 is installed on the wall next to the water seal check valve, the inductive proximity switch 2 is installed on the first bracket 1, the second bracket 6 is installed on the wall next to the water seal check valve, and the inductive proximity switch 9 is installed on the second bracket 6.

[0010] Among them, in the second step, the design and installation of water seal check valve detection instruments are as follows: the installed detection instruments include: a first intelligent pressure transmitter 2-8 and a second intelligent pressure transmitter 2-9 are installed on the connecting pipe between the three-way valve and the water seal check valve, which are used to measure the internal pressure of the connecting pipe between the three-way valve and the water seal check valve; an intelligent temperature transmitter 2-11 is installed on the connecting pipe between the three-way valve and the water seal check valve, and a mass flow meter 2-6 is installed on the air supply pipe; an intelligent liquid level meter 2-10 is installed on the water seal check valve, and the low-position installation height of the liquid level meter is at the same height as the end of the sealing rotating cover in the check valve, which is used to measure the height of the rotating cover immersed in the water seal; a flow meter 2-12 and a regulating valve 2-13 are installed on the water seal check valve pipeline.

[0011] Among them, the third step: air supply control of the connecting pipeline between the three-way valve and the water seal check valve is as follows:

[0012] According to the pressure value P1 measured by the first intelligent pressure transmitter 2-8 installed on site, the pressure value P2 measured by the second intelligent pressure transmitter 2-9, the temperature value T1 detected by the intelligent temperature transmitter 2-11, the air supply cut-off valve 2-5 and the mass flow meter 2-6, the internal air pressure of the pipeline is stabilized. Figure 3 , When the water seal check valve is in the closed state, the PLC system receives Figure 1 After the electric signal is sent by the inductive proximity switch 9, the connecting pipeline between the three-way valve and the water seal check valve starts to control the air supply. When P1<PL and P2<PL, the air supply starts. When |P2-P1|>PX or the continuous air supply time t1 exceeds the set air supply time t, the air supply cut-off valve 2-5 is closed and the air supply stops.

[0013] PX calculation formula:

[0014]

[0015] P1: The pressure value measured by the first intelligent pressure transmitter;

[0016] P2: The pressure value measured by the second intelligent pressure transmitter;

[0017] PH: Maximum pressure setting value;

[0018] PL: minimum pressure setting value;

[0019] The calculation formula for setting time t is:

[0020]

[0021] n: number of moles of nitrogen

[0022] R: Gas constant

[0023] T: absolute temperature of the gas

[0024] PH: Maximum pressure setting value

[0025] PL: minimum pressure setting value

[0026] F: Gas replenishment flow.

[0027] Under normal circumstances, when the two intelligent pressure transmitters P1 and P2 are in normal state, that is, when there is no fault, the air supply cut-off valve 5 is controlled to be cut off by "when |P2-P1|>PX" or "when the continuous air supply time t1 exceeds the set air supply time t, the air supply cut-off valve 5 is closed and the air supply is stopped". These two methods are used to judge and further control the air supply to avoid the situation where the air supply does not stop due to the fault of the intelligent pressure transmitter equipment, and then the water seal is broken.

[0028] Among them, the fourth step: control the water replenishment of the water seal check valve, specifically as follows: the liquid level L1 measured by the intelligent liquid level meter 2-10 and the water replenishment flow F1 detected by the flow meter 2-12 are used to achieve safe water replenishment of the water seal check valve. The safe water replenishment method is small flow overflow and large flow rapid water replenishment;

[0029] When the water seal check valve is in the valve closed position, Figure 1 After the inductive proximity switch 2 detects the electrical signal, it uploads the electrical signal to the PLC system. The PLC system receives the signal and determines that the water seal check valve is in the valve closed position. When L1≥LH, the water seal check valve stops replenishing water. When LL<L1<LH, a small flow rate is used to replenish water until L1≥LH, the water seal check valve stops replenishing water, and the excess water in the water seal check valve flows to the water seal well through the overflow pipe. When L1≤LL, a large flow rate is used to replenish water until L1≥LH, the water seal check valve stops replenishing water to ensure that the water level in the water seal check valve is always at a high level to prevent the water seal from being punctured. The large flow rate of water replenishment F1 and the small flow rate of water replenishment F2 are set according to the volume of the water seal check valve and the opening of the regulating valve to meet the requirement of quickly completing the replenishment of water inside the water seal check valve within time t.

[0030] Compared with the prior art, the present invention has the following advantages: the method for controlling the water seal in the water seal check valve of a wet dust removal system to prevent breakdown is described in the technical solution and the method is applicable to the wet dust removal system to control the pressure of the front section of the water seal of the water seal check valve. The water seal check valve position detection device described in the present invention can ensure the continuous detection of the signal. The air supply control method of the connecting pipeline between the three-way valve and the water seal check valve can avoid excessive pressure beyond the set range while ensuring that the pipeline is in positive pressure. Together with the water supply of the water seal check valve, the water seal in the water seal check valve can be controlled to avoid major safety accidents such as breakdown. The present method has a wide range of applications and has a good development prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of a water seal check valve state position detection device;

[0032] Figure 2 Design installation drawing for water seal check valve detection instrument;

[0033] Figure 3 This is a diagram of the gas replenishment control method.

[0034] In the figure: 1 first bracket, 2 inductive proximity switch, 3 clamp, 4 first fixing bolt, 5 rocker, 6 second bracket, 7 second fixing bolt, 8 water seal check valve shaft, 9 inductive proximity switch, 10 arc-shaped metal sensor sheet, 2-1 wet dust removal system fan, 2-2 bypass valve; 2-3 three-way valve release position, 2-4 three-way valve recovery position, 2-5 safety nitrogen electric control cut-off valve, 2-6 mass flow meter, 2-7 water seal check valve, 2-8 first intelligent pressure transmitter, 2-9 second intelligent pressure transmitter, 2-10 intelligent liquid level meter, 2-11 intelligent temperature transmitter, 2-12 water seal check valve water supply flowmeter, 2-13 water seal check valve water supply regulating valve. DETAILED DESCRIPTION

[0035] In order to deepen the understanding of the present invention, the present embodiment is described in detail below with reference to the accompanying drawings.

[0036] Example 1: See Figure 1 , a method for controlling water seal breakdown prevention in a water seal check valve of a wet dust removal system, the method comprising the following steps:

[0037] The first step is to design and install a water seal check valve status position detection device.

[0038] The second step is to design and install the water seal check valve detection instrument.

[0039] Step 3: Control the air supply in the connecting pipeline between the three-way valve and the water seal check valve;

[0040] Step 4: Control the water supply to the water seal check valve.

[0041] See also Figure 1, wherein, in the first step, the water seal check valve valve state position detection device includes a first bracket 1, an inductive proximity switch 2, a circular clamp 3, a first fixing bolt 4, a second fixing bolt 7, a swing rod 5, a second bracket 6 and a water seal check valve shaft 8, wherein the circular clamp 3 is sleeved on the water seal check valve shaft 8, the first fixing bolt 4 and the second fixing bolt 7 are installed on the circular clamp, the circular clamp 3 is connected to the swing rod 5, the swing rod 5 is connected to the arc-shaped metal sensor sheet 10, the first bracket 1 is installed on the wall next to the water seal check valve, the inductive proximity switch 2 is installed on the first bracket 1, the second bracket 6 is installed on the wall next to the water seal check valve, and the inductive proximity switch 9 is installed on the second bracket 6. The first bracket 1 is installed on the wall to provide support for the inductive proximity switch 2 and realize the telescopic manual installation and adjustment of the inductive proximity switch 2. The inductive proximity switch 2 is mounted on the first bracket 1 to detect the arc-shaped metal sensor sheet 10 and the water seal check valve opening signal. The circular clamp 3 is mounted on the water seal check valve shaft 8 and rotates with the water seal check valve shaft to drive the swing rod 5 to rotate.

[0042] The first fixing bolt 4 is installed on the circular clamp 3 to fix the position of the circular clamp 3 on the water seal check valve 8;

[0043] The swing rod 5 is a connecting piece connecting the clamp 3 and the arc-shaped metal sensing sheet 10. The clamp 3 drives the metal sensing sheet 10 to move through the swing rod 5.

[0044] The second bracket 6 is installed on the wall to provide support for the inductive proximity switch 9 and realize the telescopic manual installation adjustment of the inductive proximity switch 9.

[0045] The second fixing bolt 7 is installed on the circular clamp 3 to fix the position of the circular clamp 3 on the water seal check valve 8. The water seal check valve shaft 8 drives the clamp 3 to rotate.

[0046] The inductive proximity switch 9 is installed on the second bracket 6 to detect the arc-shaped metal sensor sheet 10 and the water seal check valve closing signal. This scheme adopts a slip-on clamp. The clamp installation does not damage the valve shaft and can be fixed with two bolts. The proximity switch sensing metal sheet is designed to be concentric with the valve shaft. The metal sensor sheet will not hit the proximity switch, which can ensure that the proximity switch is not damaged by the swing rod. The metal sheet has an arc characteristic and a wide contact surface with the proximity switch. Even if the valve shaft swings slightly due to unstable cylinder air pressure, the signal will not be lost, which can ensure continuous signal detection.

[0047] In the second step, see Figure 2, the design and installation of water seal check valve detection instruments are as follows: the installed detection instruments include: a first intelligent pressure transmitter 2-8 and a second intelligent pressure transmitter 2-9 are installed on the connecting pipe between the three-way valve and the water seal check valve, which are used to measure the internal pressure of the connecting pipe between the three-way valve and the water seal check valve; an intelligent temperature transmitter 2-11 is installed on the connecting pipe between the three-way valve and the water seal check valve, and a mass flow meter 2-6 is installed on the air supply pipe; an intelligent liquid level meter 2-10 is installed on the water seal check valve, and the low-position installation height of the liquid level meter is at the same height as the end of the sealing rotating cover in the check valve, which is used to measure the height of the rotating cover immersed in the water seal; a flow meter 2-12 and a regulating valve 2-13 are installed on the water seal check valve pipeline. The first intelligent pressure transmitter 2-8 is an intelligent pressure transmitter PT installed on the connecting pipe between the three-way valve and the water seal check valve, which measures the internal pressure of the connecting pipe between the three-way valve and the water seal check valve, and converts it into a 4-20mA electrical signal for transmission to the PLC; the second intelligent pressure transmitter 2-9 is an intelligent pressure transmitter PT installed on the connecting pipe between the three-way valve and the water seal check valve, which measures the internal pressure of the connecting pipe between the three-way valve and the water seal check valve, and converts it into a 4-20mA electrical signal for transmission to the PLC. The intelligent temperature transmitter 2-11 is an intelligent temperature transmitter installed on the connecting pipe between the three-way valve and the water seal check valve, and the water seal check valve water supply flowmeter 2-12 is a flowmeter FI installed on the water seal check valve water supply pipe, which measures the water flow in the water supply pipe and controls the valve opening of the pneumatic control valve 13. The water seal check valve water supply regulating valve 2-13 is a pneumatic regulating valve installed on the water seal check valve water supply pipe. Function: To adjust the water supply flow of the water seal check valve.

[0048] Among them, the third step: the air supply control of the connecting pipeline between the three-way valve and the water seal check valve is as follows: according to the pressure value P1 measured by the first intelligent pressure transmitter 2-8 installed on site, the pressure value P2 measured by the second intelligent pressure transmitter 2-9, the temperature value T1 detected by the intelligent temperature transmitter 2-11, the air supply cut-off valve 2-5 and the mass flow meter 2-6 are used to achieve stable air pressure inside the pipeline, such as Figure 3 When the water seal check valve is in the closed state, the PLC system receives Figure 1 After the electric signal is sent by the inductive proximity switch 9, the connecting pipeline between the three-way valve and the water seal check valve starts to control the air supply. When P1<PL and P2<PL, the air supply starts. When |P2-P1|>PX or the continuous air supply time t1 exceeds the set air supply time t, the air supply cut-off valve 2-5 is closed and the air supply stops.

[0049] PX calculation formula:

[0050]

[0051] P1: pressure value measured by the first intelligent pressure transmitter 2-8;

[0052] P2: pressure value measured by the second intelligent pressure transmitter 2-9;

[0053] PH: Maximum pressure setting value;

[0054] PL: minimum pressure setting value;

[0055] The calculation formula for setting time t is:

[0056]

[0057] n: number of moles of nitrogen

[0058] R: Gas constant

[0059] T: absolute temperature of the gas

[0060] PH: Maximum pressure setting value

[0061] PL: minimum pressure setting value

[0062] F: Gas replenishment flow.

[0063] Under normal circumstances, when the two intelligent pressure transmitters P1 and P2 are in normal state, that is, when there is no fault, the air supply cut-off valve 5 is controlled to be cut off by "when |P2-P1|>PX" or "when the continuous air supply time t1 exceeds the set air supply time t, the air supply cut-off valve 5 is closed and the air supply is stopped". These two methods are used to judge and further control the air supply to avoid the situation where the air supply does not stop due to the fault of the intelligent pressure transmitter equipment, and then the water seal is broken.

[0064] Among them, the fourth step: control the water replenishment of the water seal check valve, specifically as follows: according to the liquid level L1 measured by the intelligent liquid level meter 2-10 installed on site and the water replenishment flow F1 detected by the flow meter 2-12, the safe water replenishment of the water seal check valve is achieved. The safe water replenishment method is overflow with a small flow and rapid water replenishment with a large flow;

[0065] When the water seal check valve is in the valve closed position, Figure 1 After the inductive proximity switch 2 detects the electrical signal, it uploads the electrical signal to the PLC system. The PLC system receives the signal and determines that the water seal check valve is in the valve closed position.

[0066] When L1≥LH, the water seal check valve stops replenishing water. When LL<L1<LH, a small flow rate of water replenishment is used until L1≥LH, at which time the water seal check valve stops replenishing water. Excess water in the water seal check valve flows to the water seal well through the overflow pipe. When L1≤LL, a large flow rate of water replenishment is used until L1≥LH, at which time the water seal check valve stops replenishing water, ensuring that the water level in the water seal check valve is always at a high level to prevent the water seal from being punctured. The large flow rate of water replenishment F1 and the small flow rate of water replenishment F2 are set according to the volume of the water seal check valve and the opening of the regulating valve to ensure that the water inside the water seal check valve is quickly replenished within time t.

[0067] Embodiment 2: A method for controlling water seal breakdown prevention in a water seal check valve of a wet dust removal system, the method comprising the following steps:

[0068] The first step is to design and install the water seal check valve status position detection device.

[0069] Specific implementation: Design a water seal check valve status position detection device. The specific size of the detection device is measured and manufactured based on the on-site water seal check valve equipment.

[0070] The inductive proximity switch brackets 1 and 6 mounted on the wall have a length D = 120 and are made of angle steel.

[0071] The inductive proximity switches 2 and 9 mounted on the bracket 1 and the bracket 6 use the Schneider inductive proximity switch XS518B1DAL2.

[0072] The circular clamp installed on the rotating shaft 8 of the water seal check valve has a diameter of 300 mm and a width of 30 mm.

[0073] The length D of the connecting piece 5 installed on the circular hoop 3 is 210 mm.

[0074] The length L of the arc-shaped metal sensor sheet 10 is 6 mm, and the roundness θ is 75°.

[0075] The sensing distance between the arc-shaped metal sensing sheet 10 and the Schneider inductive proximity switch XS518B1DAL2 is 2-4 mm.

[0076] The second step is to design and install the water seal check valve detection instrument.

[0077] The details are as follows:

[0078] like Figure 21. Install an intelligent pressure transmitter 2-8 and an intelligent pressure transmitter 2-9 on the connecting pipe between the three-way valve and the water seal check valve to measure the internal pressure of the connecting pipe between the three-way valve and the water seal check valve; install an intelligent temperature transmitter 2-11 on the connecting pipe between the three-way valve and the water seal check valve; install a mass flow meter 2-6 on the air supply pipe; install an intelligent liquid level meter 2-10 on the water seal check valve, the low-level installation height of the liquid level meter is at the same height as the end of the sealing rotary cover in the check valve, and is used to measure the height of the rotary cover immersed in the water seal; install a flow meter 2-12 and a regulating valve 12-3 on the water seal check valve pipeline. The signals of the intelligent pressure transmitter 2-8 and the intelligent pressure transmitter 2-9, the intelligent liquid level meter 2-10, the intelligent temperature transmitter 2-11, the flow meters 2-6 and 2-12, and the regulating valve 2-13 enter the PLC system.

[0079] Step 3: Control method of air supply in the connecting pipeline between the three-way valve and the water seal check valve

[0080] The details are as follows:

[0081] According to the pressure value P1 measured by the intelligent pressure transmitter 2-8 installed on site, the pressure value P2 measured by the intelligent pressure transmitter 2-9, the temperature value T1 detected by the intelligent temperature transmitter 2-11, the air supply cut-off valve 2-5 and the mass flow meter 2-6, the internal air pressure of the pipeline is stabilized.

[0082] When the water seal check valve is in the closed state, the PLC system receives Figure 1 After the electric signal is sent by the inductive proximity switch in 9, the connecting pipe between the three-way valve and the water seal check valve starts to control the air supply. When P1 < 1.5pa and P2 < 1.5pa, the air supply starts. When |P2-P1| > PX or the continuous air supply time t1 exceeds the set air supply time t, the air supply cut-off valve 2-5 is closed and the air supply stops.

[0083] PX calculation formula:

[0084]

[0085] P1: The pressure value measured by the intelligent pressure transmitter 2-8

[0086] P2: The pressure value measured by the intelligent pressure transmitter 2-9

[0087] PH: Maximum pressure setting value P1 2 -P2 2

[0088] PL: minimum pressure setting value

[0089] The calculation formula for setting time t is:

[0090]

[0091] n: number of moles of nitrogen

[0092] R: Gas constant

[0093] T: absolute temperature of the gas

[0094] PH: Maximum pressure setting value

[0095] PL: minimum pressure setting value

[0096] F: Beneficial effect of air supply flow: Under normal circumstances, when the two intelligent pressure transmitters P1 and P2 are in normal state, that is, when there is no fault, the air supply cut-off valve 5 is controlled to be cut off by "when |P2-P1|>1.1pa" or "when the continuous air supply time t1 exceeds the set air supply time of 12 seconds, the air supply cut-off valve 5 is closed and the air supply is stopped". These two methods are used to judge and further control the air supply to avoid the situation where the air supply does not stop due to the failure of the intelligent pressure transmitter equipment, and then the water seal is broken.

[0097] Step 4: The water seal check valve water replenishment control method is as follows: According to the liquid level L1 measured by the intelligent liquid level meter 2-10 installed on site and the water replenishment flow F1 detected by the flow meter 2-12, the water seal check valve is safely replenished. The safe water replenishment method is overflow at a small flow rate and rapid water replenishment at a large flow rate.

[0098] When the water seal check valve is in the valve closed position, Figure 1 After the inductive proximity switch 2 detects the electrical signal, the electrical signal is uploaded to the PLC system. The PLC system receives the signal and determines that the water seal check valve is in the valve closing position.

[0099] When L1≥100, the water seal check valve stops replenishing water. When 65<L1<100, a small flow rate is used to replenish water until L1≥100, the water seal check valve stops replenishing water, and the excess water in the water seal check valve flows to the water seal well through the overflow pipe. When L1≤65, a large flow rate is used to replenish water until L1≥100, the water seal check valve stops replenishing water, ensuring that the water level in the water seal check valve is always at a high level to prevent the water seal from being punctured. Large flow water replenishment 50m 3 / h and small flow water replenishment flow 20m 3 / h is set according to the volume of the water seal check valve and the opening of the regulating valve to ensure that the water inside the water seal check valve is quickly replenished within the time 10.

[0100] The implementation effect of this method in the experimental period:

[0101] In the experimental section, this method can effectively ensure that the connecting pipeline between the three-way valve and the water seal check valve is controlled according to the set pressure value by adopting this control method. The trend of 'Qi replenishment contron' is that when the 'water seal check valve position' is at "0", that is, when the water seal check valve is in the closed position, 'Qi replenishment contron' is sawtooth-shaped, the high point of the sawtooth means that the gas replenishment stops, and the low point of the sawtooth means that the gas replenishment starts, and the whole process is controlled smoothly. When the 'water seal check valve position' is at "1", that is, when the water seal check valve is in the open position, it is in the gas recovery state at this time, 'Qi replenishment contron' is linear, and the gas replenishment does not participate in the control during this period. The connecting pipeline between the three-way valve and the water seal check valve is the gas pipeline recovery pressure, and the recovery pressure is 3.5Kpa.

[0102] It should be noted that the above embodiments are not intended to limit the protection scope of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions all fall within the protection scope of the claims of the present invention.

Claims

1. A method for controlling water seal breakdown prevention in a water seal check valve of a wet dust removal system, characterized in that: The method comprises the following steps: The first step is to design and install a water seal check valve status position detection device. The second step is to design and install the water seal check valve detection instrument. Step 3: Control the air supply in the connecting pipeline between the three-way valve and the water seal check valve; Step 4: Control the water supply to the water seal check valve.

2. The method for controlling the water seal breakdown prevention in the water seal check valve of a wet dust removal system according to claim 1, characterized in that: In the first step, the water-seal check valve valve state position detection device includes a first bracket, an inductive proximity switch, a circular clamp, a first fixing bolt, a second fixing bolt, a rocker arm, a second bracket and a water-seal check valve shaft, wherein the circular clamp is sleeved on the water-seal check valve shaft, the first fixing bolt and the second fixing bolt are installed on the circular clamp, the circular clamp is connected to the rocker arm, the rocker arm is connected to the arc-shaped metal sensor sheet, the first bracket is installed on the wall next to the water-seal check valve, the inductive proximity switch is installed on the first bracket, the second bracket is installed on the wall next to the water-seal check valve, and the inductive proximity switch is installed on the second bracket.

3. The method for controlling the water seal breakdown prevention in the water seal check valve of the wet dust removal system according to claim 2 is characterized in that: In the second step, the design and installation of water seal check valve detection instruments are as follows: the installed detection instruments include: installing the first intelligent pressure transmitter and the second intelligent pressure transmitter on the connecting pipe between the three-way valve and the water seal check valve, which are used to measure the internal pressure of the connecting pipe between the three-way valve and the water seal check valve; installing an intelligent temperature transmitter on the connecting pipe between the three-way valve and the water seal check valve, and installing a mass flow meter on the air supply pipe; installing an intelligent liquid level gauge on the water seal check valve, and the low-position installation height of the liquid level gauge is at the same height as the end of the sealing rotating cover in the check valve, which is used to measure the height of the rotating cover immersed in the water seal; installing a flow meter and a regulating valve on the water seal check valve pipeline.

4. The method for controlling the water seal breakdown prevention in the water seal check valve of a wet dust removal system according to claim 3 is characterized in that: Step 3: Control the air supply in the connecting pipeline between the three-way valve and the water seal check valve, as follows: The pressure value P1 measured by the first intelligent pressure transmitter, the pressure value P2 measured by the second intelligent pressure transmitter, the temperature value T1 detected by the intelligent temperature transmitter, the air supply cut-off valve, and the mass flow meter are used to achieve stable air pressure inside the pipeline. When the water seal check valve is in a closed state, that is, after the PLC system receives the electrical signal sent by the inductive proximity switch, the connecting pipeline between the three-way valve and the water seal check valve starts to control air supply. When P1<PL and P2<PL, air supply starts. When |P2-P1|>PX or the continuous air supply time t1 exceeds the set air supply time t, the air supply cut-off valve is closed and air supply stops. PX calculation formula: P1: pressure value measured by intelligent pressure transmitter 2-8; P2: pressure value measured by intelligent pressure transmitter 2-9; PH: Maximum pressure setting value; PL: minimum pressure setting value; The calculation formula for setting time t is: n: number of moles of nitrogen R: Gas constant T: absolute temperature of the gas PH: Maximum pressure setting value PL: minimum pressure setting value F: Gas replenishment flow.

5. The method for controlling water seal breakdown prevention in a water seal check valve of a wet dust removal system according to claim 3 or 4, characterized in that: Step 4: Control the water replenishment of the water seal check valve, as follows: the second intelligent liquid level meter measures the liquid level L1, and the flow meter detects the water replenishment flow F1 to achieve safe water replenishment of the water seal check valve. The safe water replenishment method is small flow overflow and large flow rapid water replenishment; when the water seal check valve is in the valve closed position, the inductive proximity switch detects the electrical signal and uploads the electrical signal to the PLC system. The PLC system receives the signal and determines that the water seal check valve is in the valve closed position. When L1 ≥ LH, the water seal check valve stops replenishing water. When LL < L1 When L1 is less than LH, a small flow rate is used to replenish water until L1≥LH, at which time the water seal check valve stops replenishing water, and excess water in the water seal check valve flows to the water seal well through the overflow pipe. When L1≤LL, a large flow rate is used to replenish water until L1≥LH, at which time the water seal check valve stops replenishing water, ensuring that the water level in the water seal check valve is always at a high level to prevent the water seal from being punctured. The large flow rate of water replenishment F1 and the small flow rate of water replenishment F2 are set according to the volume of the water seal check valve and the opening of the regulating valve to ensure that the water inside the water seal check valve is quickly replenished within the time t.

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