Wet electrostatic precipitator is a new dedusting equipment used to treat micro dust and micro particles, which is mainly used to remove dust, acid mist, water droplets, aerosols, odor, PM2.5 and other harmful substances in humid gases, and is an ideal equipment for controlling air dust pollution.
1、 Fault type
The faults of wet electrostatic precipitator during operation can be classified into two categories: electrical faults and faults caused by unstable operation. The main performances are:
(1) The power supply device cannot be powered on;
(2) The primary voltage and current are normal during operation, but the secondary voltage cannot be generated;
(3) The milliammeter suddenly becomes zero during operation, and the voltage is normal;
(4) Silicon rectifier control system flashover, frequent discharge and frequent tripping of power supply device;
(5) The temperature of insulator box decreases;
(6) Wall through porcelain bushing and post insulator are cracked;
(7) The corona electrode is broken;
(8) High voltage silicon rectifier tube breakdown or thyristor damage;
(9) Excessive resistance of dust remover;
(10) The explosion caused major damage to the equipment.
2、 Cause analysis
(1) The causes of electrical failure include: damage of electrical components, inadequate adjustment of corona electrode, and breakage of wall bushing and post insulator.
① Damaged electrical components, such as fuse blowing, high-voltage silicon rectifier tube breakdown or thyristor damage, can lead to power failure; If the milliammeter is damaged or the transformer fails, the phenomenon of fault type (3) will occur.
② If the nickel chromium alloy wire is not used, the corona electrode will be corroded and broken if it is not used for a long time. The tension of corona wire is uneven, and the force is uneven. The overload of individual corona electrode will also cause the corona electrode to break; If the corona electrode is not installed in place, deviates from the center of the settling tube, or has too much scale, the electric field will frequently flashover, or even the operation will be interrupted.
③ If the mechanical properties of through wall porcelain bushing and post insulator are not up to standard and can not bear the tension of upper and lower hangers, the insulator will be damaged and cracked. If the temperature control of insulator box is unreasonable and the temperature is low or drastically changed, the insulator will also be damaged and cracked; Too much dirt on the surface of the insulator will also cause the insulator to crack. The result is that the electric field is grounded, the operation of the electrostatic precipitator is interrupted, and faults (2) and (4) occur.
(2) The reasons for failure caused by unstable operation are: improper temperature control of insulator box; The gas distributor grid is blocked, and the sediment is too thick; Improper adjustment of water film; The oxygen content in the system exceeds the standard.
① Insufficient steam pressure and blocked steam pipeline may cause low temperature of insulator box. In the long run, the insulator surface temperature is low, and tar and dust particles accumulate, causing electric field short circuit. If the temperature of insulator box rises too fast, or the temperature changes dramatically during operation, the insulator will be cracked.
② If intermittent flushing cannot be carried out as required during operation, the tar accumulated on the sediment pipe wall is difficult to be cleaned, which will not only cause excessive resistance to equipment operation, but also lead to damage to the electric field.
③ During maintenance, if the water film is not adjusted as required, and the water film is uneven or not thick enough, the phenomenon described in fault (4) will occur after it is put into operation. The above situations also occur when the water film is damaged during operation.
④ The reason for the explosion of the electrostatic precipitator is that the oxygen content in the gas exceeds the standard, the mixed explosive gas is formed in the equipment and reaches explosion, and the explosion occurs when encountering electric sparks.
3、 Troubleshooting and preventive measures for wet dust remover
(1) When the electrostatic precipitator fails, the causes shall be analyzed and handled in a timely manner. Specific treatment methods include:
① First, find out the fault point and determine the cause of the fault;
② If the electrical components are damaged, replace them in time and resume operation;
③ If the fault point is in the electric field, try to increase the water volume and extend the flushing time, and the equipment can often operate stably after effective flushing;
④ If the flushing is invalid, the problem will be more troublesome, and the equipment shall be isolated for maintenance.
(2) In order to ensure the stable operation of the electrostatic precipitator and extend its service life, the maintenance quality should be improved, and the operation management and maintenance work should be strengthened.
① Nickel chromium alloy wire shall be used as corona wire as far as possible, and the verticality index shall be ensured for the adjustment of corona electrode. The deviation from the center shall be less than 3mm, and the disease shall be checked and adjusted regularly; Changing the tightening weight of the corona electrode to the locking mode can reduce the floating degree of the corona electrode under the action of the airflow and maintain the normal operation of the electric field.
② During each maintenance, ensure that the sedimentation pipe is cleaned and the inner wall is smooth and flat; The water film shall be adjusted evenly with a thickness of 8mm~10mm; Insulators must undergo voltage withstand test to ensure good insulation.
③ During operation, the temperature of insulator box shall be controlled at 70 ℃~90 ℃ to avoid low temperature and sudden temperature change. Process discipline shall be strictly enforced to ensure that intermittent flushing operation can be seriously implemented.
④ Check the oxygen content in the gas on time, especially when the electric precipitator is used for purging.
⑤ Wipe and clean the insulator surface every six months to ensure that the surface is clean.
⑥ Regularly check the oil quality of the transformer and replace the faulty electrical components in time.
Post time: Aug-12-2022