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E-mail
549001739@qq.com
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Phone
13301403246
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Address
Building 4, Jinhu Square, Jinhu Industrial Park, Jinhu County, Jiangsu Province
Jiangsu Jinhu Huasheng Measuring Instrument Co., Ltd
549001739@qq.com
13301403246
Building 4, Jinhu Square, Jinhu Industrial Park, Jinhu County, Jiangsu Province
The pressure and differential pressure in the coal mill, air preheater and other parts of the battery are directly sampled using pressure pipes, and the fault of clogged sampling gauge pipes often occurs.
Fault symptoms: manifested as no change in pressure, increase in differential pressure, non operation of switches, increase in pressure, decrease in differential pressure, etc.
Reason for malfunction:
1) Design flaw: The first phase of the electrification system did not have a sampling tube blowing device in the design, resulting in frequent blockage of the sampling tube by coal powder or ash. Although a sampling tube blowing device was designed for the second phase, it has not been put into normal use. After discovering this issue, the relevant personnel in the thermal engineering room contacted and put into use the relevant blowing device, but it was not approved. The main concern was that the blowing device would affect the operating conditions of the equipment during and after use.
2) No buffer tank: No buffer tank was installed at the sampling port in the design.
3) Failure to blow: The sampling design of the first phase coal mill with electric support is a sampling port with multiple devices, such as pressure, differential pressure, switches, etc. During blowing, due to limitations in working conditions, time, measures, etc., not all sampling pipelines were completely blown clean, leaving hidden dangers
Processing method: blow and sweep
Processing effect: The current method for the second phase equipment is to blow first when there is a problem with the equipment, and then put the blowing device into use. After putting the blowing device into use, the number of blowing times is significantly reduced. When it comes to minor or major repairs, blowing all sampling tubes and putting all sampling blowing devices into use is believed to have a significant improvement. Due to equipment limitations, the first phase only requires immediate purging when problems arise. A renovation plan has been proposed to address this issue.
Accident phenomenon: The measuring point shows irregular fluctuations
Cause of the accident:
1) Loose wiring of on-site equipment.
2) Loose wiring in the junction box.
Handling method:
1) Search for loose parts.
2) Re tighten.
3) Replace screws that cannot be tightened immediately.
Solution effect: The reason for loose screws is twofold: firstly, they were not tightened properly during installation and debugging; secondly, due to the lack of anti loosening washers, the unit experienced significant long-term vibration. We have proposed a plan to purchase anti loosening gaskets and gradually replace them to reduce such accidents.
Accident phenomenon: The minimum or maximum indication of the measuring point becomes a bad point
Cause of the accident:
1) Loose wiring of on-site equipment.
2) Loose wiring in the junction box.
3) The on-site equipment wiring is short circuited.
4) The wiring of the junction box is short circuited.
5) The temperature component is short circuited and damaged.
6) The temperature element is open circuit and the element is damaged.
Handling method:
1) Measure the resistance of the temperature sensor.
2) Check the on-site wiring.
3) Check the wiring of the junction box.
4) Replace the temperature element.
5) Tighten or replace screws.
Processing effect: For repeatedly damaged components, replace the sampling location and special protective sleeves. After tightening the loose parts, the performance is good.
Fault phenomenon: The soot blower does not operate and exceeds the limit position
Reason for malfunction:
1) Travel switch does not operate: Due to mechanical jamming, the switch does not operate. The switch itself is damaged, causing it to malfunction. The mechanical limit exceeds the limit, and the switch cannot automatically reset, resulting in non operation.
2) The position of the travel switch is not set properly: if the position is set too far forward or backward, the soot blower cannot stop when it reaches its position and continues to move, causing the soot blower to dislocate and requiring resetting of the limit.
3) Line fault: The line is virtual or loose, causing the switch to fail or malfunction.
Handling method:
1) Check the switch: whether the switch is stuck, whether the action is flexible and accurate.
2) Position inspection: Manually operate the soot blower and observe whether the stroke is in place and whether it exceeds the limit. Reasonably and correctly set the switch position.
3) Circuit inspection: Check for loose connections in the circuit, tighten the wiring terminals, and replace necessary accessories such as screws.
Processing effect: The main problem with the soot blower lies in the travel switch. As long as the travel switch is carefully and meticulously reset, the thermal part can ensure good operating conditions.
Fault phenomenon: Frequent misoperation of the switch
Reason for malfunction:
1) Design issue: If the installation location of the second phase low pressure level switch is too far away from the equipment, a longer connecting pipeline is required. Firstly, there is a lag in response time. Secondly, the temperature of the low-pressure heater is higher, and the longer connecting pipeline requires higher insulation requirements. The issue of gas emissions inside the pipeline was not considered during design, and there are several bends in the pipeline.
2) Construction problem: The construction was not strictly carried out according to the requirements, and the pipeline layout was horizontal.
3) Gas impact: Due to the above two reasons, gas in the sampling bucket and sampling tube cannot be discharged and accumulates, causing high temperatures in the sampling bucket and sampling tube, resulting in liquid level fluctuations and misoperation of the switch.
Solution: Since the operation of the Phase II equipment, there have been frequent issues with the low pressure liquid level switch,
Before the renovation, only mandatory interlocking was implemented to avoid more serious consequences caused by misoperation of switches. During the temporary maintenance period, modifications were made to the low-pressure sampling of Units 3 and 4. Change all bends of the original sampling tube to straight sections and strictly follow the standard construction to avoid gas accumulation inside the tube.
Processing effect: After one week of observation, the operation effect was good after the transformation, and the interlocking force was released and put into normal use. Since its launch, it has been running well.
Fault phenomenon: The gate does not move
Reason for malfunction:
1) Door violation card.
2) Switch feedback fault: Due to the harsh environment in which the pebble coal is located, the mechanical part of the switch is filled with ash, causing the switch to jam and unable to operate correctly. The switch body is dusty, causing the switch to fail to operate correctly. The switch itself is faulty, causing the switch to fail or malfunction.
3) Local button (transfer switch) malfunction: Due to long-term vibration, the local button (transfer switch) has become loose. The operator did not notify the maintenance personnel and forcibly operated it, causing damage to the switch. The button (conversion switch) itself is faulty, causing the switch to fail or malfunction.
Handling method:
a) Notify the maintenance personnel to handle the issue of door jamming.
b) Check and clean the switch: Check whether the switch action is good, whether there is dust entering, and whether the action feedback is correct.
c) Check the local button (transfer switch): Check whether the local button (transfer switch) is loose, whether the action is good, whether it is correct, and tighten the local button (transfer switch).
Processing effect: The processing effect is good. On the one hand, use high-quality buttons (toggle switches) and strengthen inspection efforts and frequency to prevent such accidents before they occur. In addition, regularly clean the accumulated dust on the travel switch and take preventive measures.
Fault phenomenon: The feedback of the coal mill outlet gate is incorrect or the gate cannot move
Reason for malfunction:
1) Switch feedback fault: Due to the harsh environment, the mechanical part of the switch entered dust, causing the switch to jam and unable to operate correctly. The switch body is dusty, causing the switch to fail to operate correctly. The switch itself is faulty, causing the switch to fail or malfunction.
2) Due to inadequate feedback from the switch, the program cannot execute correctly. For example, if the signal to close in place when it should be opened does not return, the feedback is incorrect and the door cannot move.
Solution: Check and clean the switch: replace it with a switch of better quality. Check whether the switch action is good, whether there is dust entering, and whether the action feedback is correct.
Processing effect: The processing effect is good. Strengthen the intensity and frequency of inspections to prevent such accidents before they occur, regularly clean the accumulated dust on the travel switch, and take preventive measures. If there is a problem with the switch itself, replace it with a switch of better quality in a timely manner.
Fault phenomenon: The feedback of the sealing air door of the coal mill is incorrect or the door cannot move
Reason for malfunction:
1) Switch feedback fault: Due to the harsh environment, the mechanical part of the switch entered dust, causing the switch to jam and unable to operate correctly. The switch body is dusty, causing the switch to fail to operate correctly. The switch itself is faulty, causing the switch to fail or malfunction.
2) Due to inadequate feedback from the switch, the program cannot execute correctly. For example, if the signal to close in place when it should be opened does not return, the feedback is incorrect and the door cannot move.
Solution: Check and clean the switch: replace it with a switch of better quality. Check whether the switch action is good, whether there is dust entering, and whether the action feedback is correct.
Processing effect: The processing effect is good. Strengthen the intensity and frequency of inspections to prevent such accidents before they occur, regularly clean the accumulated dust on the travel switch, and take preventive measures. If there is a problem with the switch itself, replace it with a switch of better quality in a timely manner.
Fault phenomenon: Incorrect feedback or inability to operate ignition and oil gun faults
Reason for malfunction:
1) Solenoid valve malfunction: Due to the harsh environment, dust enters the interior of the solenoid valve, causing it to malfunction, resulting in air leakage and leakage of the solenoid valve, causing the point and oil gun to malfunction or not operate properly.
2) Switch feedback fault: Due to the harsh environment, the mechanical part of the switch entered dust, causing the switch to jam and unable to operate correctly. The switch body is dusty, causing the switch to fail to operate correctly. The switch itself is faulty, causing the switch to fail or malfunction.
3) Due to inadequate feedback from the switch, the program cannot execute correctly. For example, if the signal to close in place when it should be opened does not return, the feedback is incorrect and the door cannot move.
Handling method:
1) Check and clean the solenoid valve: manually test run and observe whether the solenoid valve operates properly. If there is a problem with the solenoid valve, disassemble it for cleaning, lubrication, and reinstallation. Replace the solenoid valve with a new one.
2) Check and clean the switch: replace it with a switch of better quality. Check whether the switch action is good, whether there is dust entering, and whether the action feedback is correct.
Processing effect: The processing effect is good. Strengthen the intensity and frequency of inspections to prevent such accidents before they occur. Regularly clean the dust accumulation of solenoid valves and travel switches and take preventive measures. If there are problems with the solenoid valve and switch themselves, replace them with high-quality ones in a timely manner
Fault phenomenon: Furnace tube leakage often leads to false alarms
Reason for malfunction: caused by unstable equipment quality. The device operates extremely unstable, and the sensitivity of its electronic components is difficult to grasp. There is no clear expression in the manual, and there is no specific plan or standard consulted with the manufacturer.
Handling method:
1) Use the manufacturer's matching testing equipment to inspect the secondary meter.
2) Adjust the sensitivity of the secondary meter.
3) Replace the experiment with another component.
4) Replace the experiment with other secondary components.
5) Replace the primary or secondary element.
Processing effect: The effect is not very good, and there are repeated failures. We have contacted the manufacturer to handle it.
Fault phenomenon: Leakage and blockage of furnace tubes often trigger alarms
Reason for malfunction: The detection tube is indeed clogged with dust, causing an alarm to appear. The reason for the blockage is that the detection device is equipped with a regular blowing device, but the operating personnel do not use the device, resulting in the blockage of the detection tube.
Handling method:
1) Remove the primary component.
2) Poke open the dust.
3) Reinstall.
4) Check if there is an alarm.
Handling effect: All are emergency methods, without fundamentally solving the problem.
Fault phenomenon: The feedback of the air damper damper in the smoke and air system is incorrect or the damper cannot move
Reason for malfunction:
1) Door jamming: This reason accounts for the majority of such malfunctions.
2) Switch feedback fault: Due to the harsh environment, the mechanical part of the switch entered dust, causing the switch to jam and unable to operate correctly. The switch body is dusty, causing the switch to fail to operate correctly. The switch itself is faulty, causing the switch to fail or malfunction.
3) Due to inadequate feedback from the switch, the program cannot execute correctly. For example, if the signal to close in place when it should be opened does not return, the feedback is incorrect and the door cannot move.
Handling method:
1) Notify the maintenance personnel to handle it.
2) Check and clean the switch: Check whether the switch action is good, whether there is dust entering, and whether the action feedback is correct.
Processing effect: Strengthen inspection intensity and frequency to prevent such accidents before they occur, regularly clean the accumulated dust on the travel switch, and take preventive measures. If there is a problem with the switch itself, replace it with a switch of better quality in a timely manner.
Fault phenomenon: High or low pressure indication
Reason for malfunction:
1) Zero drift of transmitter.
2) The transmitter is leaking.
Handling method:
1) Close the secondary door.
2) Use a handheld device to check the zero point of the transmitter.
3) Adjust the zero point of the transmitter.
4) Check for leaks.
Processing effect: Zero drift of the transmitter is a normal phenomenon, and the effect is good after processing. Sometimes it is an external problem of the transmitter, such as leakage, but the effect is good after treatment.
Fault phenomenon: inaccurate or damaged pressure gauge indication
Reason for malfunction:
1) Quality issue: Some local meters have poor manufacturer selection, resulting in poor instrument quality and damage.
2) Improper selection: Improper selection of the local meter range, with a small range, can easily cause damage due to instrument fluctuations. At the outlet of the pump body, a vibration resistant surface should be selected, but a regular pressure gauge is used, which causes damage
3) Installation issue: In areas with significant fluctuations, no dampers were installed, resulting in instrument damage.
Handling method:
1) Disassemble and verify.
2) Check and repair.
3) Replace the watch with a new one.
4) Add dampers.
Processing effect: The processing effect is good, and there are basically no repeated failures. Due to the limited impact of equipment operating conditions and constraints of spare parts, it is not possible to have a comprehensive understanding
Fault phenomenon: inaccurate flow indication, no indication
Reason for malfunction: The flowmeter uses a pulsator rotor. Due to the dirty liquid being measured in the measuring tube, small and soft objects such as plastic and raw material tape in the liquid are wrapped around the pulsator, causing it to rotate flexibly or not, and even causing damage to the pulsator, thereby affecting the accuracy of measurement or causing equipment damage.
Handling method:
1) Remove the rotor.
2) Clean the pulsator.
3) Replace the rotor.
4) Reinstall the rotor.
Processing effect: Due to the influence of operating conditions, such faults cannot occur. A renovation plan has been proposed to replace the existing flow meters with non-contact flow meters (ultrasonic flow meters).
Fault phenomenon: Incorrect feedback or door not functioning
Reason for malfunction:
1) Quality issue: The feedback switch of the pneumatic door uses a micro switch, which is of poor quality. Due to its own problems, the switch feedback is incorrect.
2) Fixed method issue: The micro switch is fixed with only two diagonal screws, and the force of the pneumatic door switch is relatively large, which causes the switch to shift over time and cannot provide correct feedback
Handling method:
1) Check if the switch is functioning properly.
2) Check if the switch action is correct.
3) Replace the switch.
4) Re tighten the switch.
Processing effect: For loose switches, the effect is good after tightening. After replacing the damaged switch with a new one and readjusting the fixed position, the effect was good.
Fault phenomenon: Leakage of pressure reducing valve or poor operation of pneumatic valve
Reason for malfunction:
1) Gas corrosion: The environment where the hydrogen station is located contains a large amount of corrosive gases, which cause significant corrosion to the sealing ring of the pressure reducing valve. Prolonged corrosion can damage the sealing ring, leading to leakage of the pressure reducing valve. When the leakage is severe, it can cause poor operation of the pneumatic door.
2) Quality issues with pressure reducing valves.
Handling method:
1) Disassemble the pressure reducing valve.
2) Replace the gasket and sealing ring.
3) Tighten and reinstall.
4) Replace the pressure reducing valve.
Processing effect: It is recommended to replace all pressure reducing valves with highly corrosion-resistant ones.
Fault phenomenon: High exhaust temperature alarm frequently occurs
Reason for malfunction:
1) Mechanical issue: Failure to replace filter screens and grease on time.
2) Original issue: The temperature measuring element uses a thermistor, which caused an alarm due to component damage in China.
Handling method:
1) Notify the maintenance personnel to handle it.
2) Alarm confirmation and elimination.
3) Restart.
Processing effect: Due to insufficient spare parts, repetitive work is often done.