large Dust exhaust centrifugal fan Fans can be divided into axial flow fans, centrifugal fans and diagonal flow (mixed flow) fans according to the flow direction after the airflow enters the impeller. Fans are divided into press in local fans (hereinafter referred to as press in fans) and flame-proof motors placed outside or inside the flow channel, and flame-proof motors placed inside the explosion-proof sealing chamber of the extraction type local fans (hereinafter referred to as extraction fans) according to their purposes. Dust exhaust centrifugal fan company Fans can also be divided into single-stage, two-stage or multi-stage pressurization fans according to the form of pressurization. For example, 4-72 is single-stage pressurization, and high-end fan is multi-stage pressurization fan. Fans can be divided into axial flow fans, mixed flow fans, roof fans, air conditioning fans, etc. Fan can be divided into negative pressure fan, low pressure fan, medium pressure fan and high pressure fan according to pressure. According to the outlet pressure (pressure rise), it can be divided into: ventilator (≤ 15000 Pa), blower (15-350000 Pa), compressor (≥ 350000 Pa)

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.

While meeting the new standard, the wet electrostatic precipitator can also control the haze fine particles, sulfur trioxide aerosol droplets, organic pollutants, heavy metal pollutants, etc., which has great social benefits. The air pollutant control mode of SCR+ESP/FF+WFGD+WESP is also a relatively effective way to control pollutants in Shangshan Coal fired Power Plant. Dust exhaust centrifugal fan company Common dust control technologies, among which the dry electrostatic precipitator, the electrostatic fabric composite precipitator and the bag type precipitator are used as the front section dust control technology, cannot guarantee the ultra clean emission of flue gas dust after the desulfurization device, while the wet electrostatic precipitator arranged at the downstream of the wet desulfurization device will be used as a reliable terminal dust control technology. The working principle of wet electrostatic precipitator is similar to that of dry electrostatic precipitator. It is high-voltage corona discharge that charges dust or water mist, and charged particles reach the dust collecting plate under the action of electric field force, large Dust exhaust centrifugal fan However, in terms of the way of dust, the dry electrostatic precipitator uses mechanical vibration, while the wet electrostatic precipitator uses flushing fluid to flush electricity, washing the dust captured on the dust collection plate into the ash hopper and then discharging the wet electrostatic precipitator. The advantages of the wet electrostatic precipitator are: because the mass and heat transfer processes occur simultaneously in the process of gas and liquid contact, this type of precipitator has the function of dust removal, It also has the function of flue gas cooling and absorption of harmful gases. Suitable for high temperature. High temperature, flammable, explosive and harmful gases; Normal operation and high purification efficiency; Dust and gas that can be used for gathering fog and dust; Exhaust volume balance; Simple structure. Low investment, convenient operation and maintenance.

The operating principle of wet electrostatic precipitator is different from other equipment. The dusty gas enters the expanded ash hopper of the wet electrostatic precipitator for pre collection, and is evenly distributed between each filter bag through the guide plate. The dust is retained on the surface of the filter bag. In order to make the equipment resistance not exceed 1200pa, the high-pressure gas will pulse through the electromagnetic pulse valve, so that the compressed air in the air bag will be ejected from the nozzle hole (called primary air) The surrounding air (called secondary air), which is several times of the primary air, is induced through the venturi to enter the filter bag to make the filter bag expand rapidly in an instant, and shake off the dust with the reverse effect of the air flow to reach the purpose of ash removal. The microcomputer automatic control device is used to adjust the ash cleaning cycle and pulse spraying time randomly according to the dust concentration, so that the dust collector can operate within the resistance range. When changing the bag of the wet electrostatic precipitator, open the top bag changing cover and directly pull out the filter bag, which is simple and convenient to protect. Chengdu large Dust exhaust centrifugal fan Wet electrostatic precipitators are mostly used in bag type precipitators. Dust removal bags are installed in the gas box. Wet electrostatic precipitators are mostly external filter type. Dust is collected in the ash hopper of wet electrostatic precipitators through the injection of pulse solenoid valves. The wet electrostatic precipitator is installed in a simple structure. This device is planned as an internal filtering structure, which can change the external pressure of the wet electrostatic precipitator to the internal pressure. In this way, the shell of the wet electrostatic precipitator can be structured without external iron plate sealing, which saves costs and does not hinder the use of the wet electrostatic precipitator. The processing of wet electrostatic precipitator is particularly important. In recent years, some Dust exhaust centrifugal fan company Small manufacturers use small sewing machines as processing equipment, and use low-quality thread as raw materials during processing, which is fake, and the processing level is far behind. The wet electrostatic precipitator will open lines, cracks, and drop the bottom after a short time of operation. Although the size of the cloth bag is slightly smaller, it can also be used, but after absorbing the dust with large specific gravity, the bag will drop after a period of use.

The key points of factors to be considered in the technical approach to the transformation of wet electrostatic precipitators: the wet electrostatic precipitators built before the mid-1970s could not meet the requirements of the new emission standards because of the low requirements for boiler smoke and dust emissions, the small selection of equipment capacity, the outdated structure of electrostatic precipitators, aging of dust removal equipment, low dust removal efficiency and other reasons, These electrostatic precipitators have a problem of transformation to further improve efficiency. large Dust exhaust centrifugal fan company The improvement measures for the original equipment should be considered from both technical and economic aspects, and the following technical approaches are generally adopted: 1. Discover the potential of electrostatic precipitator equipment. For example, adjust the rapping cycle and rapping force of the electrode to improve the corona power and reduce the re flying of dust; Improve the uneven distribution of flue gas velocity and readjust the technical parameters of the airflow distribution device; Adjust the control mode or power supply mode of the power supply equipment. 2、 large Dust exhaust centrifugal fan Combination with other dedusting equipment. That is, a primary precipitator is added before or after the electrostatic precipitator. 3. Increase the capacity (or dust collection area) of the electrostatic precipitator. That is, add an electric field, or increase or widen the electric field of the electrostatic precipitator.

The selection of fans Product performance and fan performance listed in the selection table are based on the performance of delivering air under standard conditions. Therefore, when the use condition is non-standard, the H4-72-12 centrifugal fan must convert the use performance into the performance under standard conditions according to the relationship in the table above, and then select according to the performance and selection table. （3） Treatment of excessive or insufficient flow During use, excessive or insufficient flow often occurs. There are many reasons for this phenomenon. If the flow is high and low during use, it is mainly because the resistance in the pipe network is high and low, or the fan works in a non working area. If it is gradually reduced after a long time during use, it is mainly due to pipe network blockage. After the fan is newly installed, the flow is too large or insufficient during the formal operation. The main reasons for this phenomenon are as follows: 1. The actual value of pipe network resistance is too different from the calculated value. In the general pipe network characteristic equation, H=KQ2, if the actual value K of K-resistance coefficient is less than the calculated value K, the flow will increase; If the actual value K is greater than the calculated value K, the flow decreases. See (b) below.