major Dust exhaust centrifugal fan The reasons for failure caused by unstable operation are: improper temperature control of insulator box; The gas distributor grid is blocked, and the sediment electrode has too thick scale; 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 violently during operation, the insulator will be cracked. ② Dust exhaust centrifugal fan Price If intermittent flushing cannot be carried out as required during operation, the tar accumulated on the sediment pipe wall is difficult to be thoroughly cleaned, which, accumulated over time, not only causes excessive resistance to equipment operation, but also leads to damage to the electric field. ③ During maintenance, the water film is not adjusted as required, the water film is uneven or not thick enough, and after putting into operation, the phenomenon described in fault (4) will occur. The above situation also occurs 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 the explosion limit, and the explosion occurs when encountering electric sparks.
2. The influence of the total pressure deviation Δ H of the fan itself was not considered during selection. When the actual total pressure of the fan was positive deviation, the flow increased; When the actual total pressure of the fan is negative deviation, the flow decreases. See (a) below. The relationship between the deviation of the pipe network characteristic curve and the total pressure and the flow can be eliminated by one of the following methods when the fan starts to officially operate after new installation, or when the flow is too large or too small during use. 1. Use the opening and closing of throttling device to adjust the flow. 2. Increase or decrease the flow by increasing or decreasing the fan speed. 3. Use a new fan with higher or lower pressure to increase or decrease the flow. 4. Change the pipe network to reduce the resistance coefficient of the pipe network to increase the flow. It must be pointed out that throttling devices are generally used to regulate the flow. However, when the actual flow is much larger than the required flow, this method wastes too much power and is very uneconomical. If conditions permit, the fan speed is usually reduced or the fan with lower pressure is replaced. When the throttling device is fully open, the flow is still too small. At this time, the throttling device has lost its function, so try to reduce the resistance coefficient of the pipe network to increase the flow, or increase the fan speed and replace the fan with higher pressure. However, the speed of the fans directly connected to the motor and the coupling cannot be changed generally. Only the fan driven by the pulley can increase or decrease the speed by changing the diameter of the pulley, but the speed of the fan cannot exceed the speed max in the performance and selection table.
Main working principles of wet electrostatic precipitator: major Dust exhaust centrifugal fan Spray the water mist to the discharge electrode and corona area, the water mist will split and further atomize after being charged in the powerful corona field formed by the barbed electrode, and the collision interception, adsorption and coagulation of electric field force and charged water mist will jointly trap the dust particles, and finally the dust particles will reach the dust collector under the drive of electric field force and be trapped. The water forms a continuous water film on the dust collecting electrode, and the captured dust is washed into the ash hopper and discharged with water. Operating principle of wet electrostatic precipitator. The dedusting process of electrostatic precipitator can be divided into four stages: gas ionization; The dust is charged with ions; Charged dust moves towards the electrode; Remove the dust on the electrode. Only the objects removed by wet electrostatic precipitation are dust and droplets, but their working principles are different due to the differences in physical characteristics between droplets and dust. In principle, Shiyan Dust exhaust centrifugal fan First of all, the existence of water droplets has an impact on the electrode discharge. To form emitting ions, free electrons in the metal electrode must obtain enough energy to overcome the ionization energy and cross the surface barrier to become emitting electrons. It is an effective measure to reduce the surface barrier by bringing water on the electrode surface. After the metal surface is covered with water, the original "metal air" interface is divided into "metal water" interface and "water air" interface. The potential barrier of the latter two interfaces is much lower than that of the former interface. In this way, after the metal surface is filled with water, the original high barrier will be divided into two low barriers, which will greatly weaken the blocking effect of the surface barrier on free electrons and make electrons easy to launch. In addition, Dust exhaust centrifugal fan Price Under the action of electric field, various impurity ions in water can easily cross the surface barrier and become emission ions. All of these have changed the electrode discharge effect, enabling corona discharge under low voltage. Secondly, due to the existence of water droplets, the resistance of water is relatively small. When water droplets combine with dust, the specific resistance of dust with high specific electricity decreases, so the working state of wet electrostatic precipitator will be more stable; In addition, since the wet electrostatic precipitator is washed by water flow and has no rapping device, it will not produce secondary dust.
The fan is allowed to start at full voltage or at reduced voltage, but it should be noted that the current at full voltage starting is about 5~7 times the rated current, and the reduced voltage starting torque is proportional to the square of the current. When the grid capacity is insufficient, the reduced voltage starting should be used. (When the power is greater than 11KW, it is advisable to adopt the step-down starting.) When the fan is in test run, Dust exhaust centrifugal fan Price Carefully read the product manual and check whether the wiring method is consistent with the wiring diagram; Carefully check whether the working voltage of the power supply to the fan meets the requirements, whether the power supply is out of phase or in phase, and whether the capacity of the electrical components provided meets the requirements. During commissioning, the number of people shall not be less than two. One person shall control the power supply and the other person shall observe the operation of the fan. If any abnormality is found, stop the machine immediately for inspection; First, check whether the rotation direction is correct; After the fan starts to run, immediately check whether the running current is balanced and whether the current exceeds the rated current; major Dust exhaust centrifugal fan If there is no normal phenomenon, stop the machine for inspection. After five minutes of operation, stop the machine to check whether the fan is abnormal, and start the machine again after confirming that there is no abnormal phenomenon. When the two speed fan is tested, start the low speed fan first and check whether the rotation direction is correct; When starting the high-speed train, the fan must be stopped before starting to prevent the switch tripping and motor damage caused by high-speed reverse rotation. When the fan reaches the normal speed, check whether the input current of the fan is normal, and the operating current of the fan cannot exceed its rated current. If the operating current exceeds its rated current, check whether the voltage supplied to the fan is normal. The motor power required by the fan refers to the higher power required for centrifugal fan and fan box when the air inlet is fully open under certain working conditions. If the air inlet is fully opened for operation, the motor may be damaged. During fan commissioning, it is better to close the valve on the inlet or outlet pipeline of the fan, open the valve gradually after operation until the required working condition is reached, and pay attention to whether the operating current of the fan exceeds the rated current