Factors influencing the efficiency of electrostati

2022-08-23
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Factors affecting the efficiency of electrostatic precipitators and relative measures

the flue gas produced by pyrometallurgical copper smelting production contains harmful gases and dust, so a huge amount of money is invested in flue gas treatment. For the initial purification of flue gas, the copper smelting industry uses more cyclone dust collectors and electric dust collectors. At the initial stage of the establishment of our factory, the electrostatic precipitator designed by Nanchang Design Institute and installed by an enterprise in Beipiao adopts two-point hanging. Later, the 40 ㎡ electrostatic precipitator of the ring block friction and wear experimental machine, which evaluates the smooth function of various smoothing agents, was designed and installed by a Taixing enterprise, using four point hanging. Both have good initial effect and low failure rate. In the later stage, the failure rate is relatively high, and the dust collection efficiency is also reduced. Therefore, engineers and technicians have done a lot of work on how to improve the efficiency of electrostatic precipitator and deal with faults, and accumulated some experience, which is summarized for your reference

electrostatic precipitator

the main function of the electrostatic precipitator is to collect the dust in the flue gas and preliminarily purify the flue gas. The structure of electrostatic precipitator is not complex, which is regularly arranged by cathode line and anode plate, and arranged alternately according to a certain spacing. High and low voltage power supply drive. Cathode and anode rapping devices are installed and controlled by PLC

electrostatic precipitator makes full use of DC high voltage to ionize the gas and produce corona discharge at the electrode. When charging the dust, the dust will gather to the anode plate and attach to the anode plate under the action of strong electric field force, so as to separate the dust from the gas. Among them, the biggest feature is that the design efficiency is high, and the resistance loss is relatively small. Among them, the power consumption and flue gas treatment volume of the fan are also relatively large, and the adaptability to the flue gas concentration is relatively good. Among them, the one-time investment and steel consumption are relatively large, and the requirements of floor area and manufacturing and installation are also relatively high

the cost of electrostatic precipitator is relatively high, but it has been widely used in Pyrometallurgical industry because of its large amount of flue gas and high dust removal efficiency

factors affecting the dust collection efficiency of the electrostatic precipitator and corresponding measures

factors affecting the dust collection efficiency mainly depend on the voltage between the corona electrode and the dust collection electrode, but its best voltage value is affected by the composition of flue gas entering the electrostatic precipitator, specific resistance, temperature, concentration, flue gas flow rate, electrode spacing, electrode shape, wide measurement range, high accuracy, fast response and other characteristics The thickness of the ash layer deposited on the electrode. The designer has considered the influencing factors and solved them in the design, but the actual situation will change. We need to constantly adjust and control them in order to effectively ensure the dust collection efficiency of the electrostatic precipitator

in winter, the outdoor temperature can reach minus 30 ℃, and the flue gas of our factory contains sulfur components. At a certain temperature, there will be condensation, which will seriously corrode the metal shell and parts. Therefore, the inlet temperature of electric dust collection in our factory is controlled at 280 ℃ -350 ℃. The voltage is controlled at kV. The flue gas flow will change with the working conditions of bottom blowing furnace and continuous blowing furnace, and the flow rate entering the electric dust collector will also change. In order to control the micro negative pressure operation in the furnace and ensure the dust collection efficiency of the electric dust collector, it is necessary to adjust the flow of the front and rear fans, adjust the secondary voltage of the electric dust collector, and adjust the rapping frequency and intensity of the cathode line and anode plate

PLC automatic control is still adopted for electric dust collection at present. The operating parameters can be adjusted according to the actual situation

the air leakage rate of the electrostatic precipitator affects the dust collection efficiency, so the air tightness test is carried out after the installation of the electrostatic precipitator, and planetary valves with good air tightness are installed at the outlet of the dust scraper, which basically meets the technical requirements. However, after several years of operation, due to improper control or too long shutdown time, it is not well maintained, the shell weld is cracked, and some parts are corroded and have holes. Therefore, during the annual overhaul, it is necessary to carefully check and repair, and control the air leakage rate of electrostatic precipitator within the scope of technology

the dust accumulation and frosting of the insulation device affect the dust collection efficiency of the electrostatic precipitator. The first insulation device is the porcelain bottle used for cathode and anode rapping devices, and the second is the quartz bushing used for cathode wire hanging. For porcelain bottles, it is mainly dust deposition, which reduces the insulation performance, causes insulation device breakdown or low voltage rise, and affects the dust collection efficiency. Therefore, reasonable rapping and manual dust removal are required. For the quartz casing, we are mainly worried about the "creepage" phenomenon caused by flue gas condensation, so we add a heater on the outer edge of the quartz casing to control the temperature in the quartz casing incubator

the reduction of dust collection efficiency in our factory is also related to the inadequate maintenance of the rapping device. The falling parts cause the cathode and anode to short circuit, and the pressure rise cannot rise. The dust collection efficiency is greatly reduced

the distance between cathode and anode also affects the dust collection efficiency. Previously, the cathode was suspended at two points, with poor stability. After a period of operation, it shifted or deflected at a small angle under the action of vibration, so that the gap between cathode and anode was large on one side and small on the other, which affected the pressure rise and reduced the dust collection effect. At present, four point hanging is adopted and fixed with a frame to ensure the stability of the gap between cathode and anode without losing the fighter

uneven air distribution will also affect the dust collection efficiency, so distribution plates are installed at the inlet and outlet to make the air flow enter evenly. However, due to high temperature and corrosion, the distribution plate will be deformed and loosened, resulting in uneven air distribution, which will reduce the dust collection efficiency. Therefore, regular inspection and correction are required

professional management is not in place

because the temperature of the electrostatic precipitator is often low, resulting in the continuous rise of corona starting voltage. If the load of the transformer is exceeded, some electric fields of the electrostatic precipitator will operate abnormally, the professional management is not in place, and the maintenance work is not as good as that. You should clearly inform the customer that such samples can only be held by winding method, which will make the electrostatic precipitator work with faults, The efficiency of dust removal is further reduced

only by formulating relatively reasonable operation specifications, the staff can implement the system, monitor and record the operation of the electrostatic precipitator in time, and take various measures at any time according to the data changes to ensure the efficient operation of the equipment

some problems will inevitably appear in the continuous operation of the electrostatic precipitator. In order to correctly deal with these problems and ensure the long-term and stable operation of the electrostatic precipitator, it is necessary to analyze the structure, working principle and flue gas composition of the electrostatic precipitator, find out the factors and countermeasures that affect the efficiency of the electrostatic precipitator, and improve the ability to judge and deal with the faults of the electrostatic precipitator according to our accumulated experience in the operation and maintenance of the electrostatic precipitator

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