Zhangjiajie large Centrifugal fan Fan performance parameters. The performance parameters of fan mainly include flow, pressure, power, efficiency and speed. In addition, the size of noise and vibration is also the main fan design index. Flow, also known as air volume, is expressed by the volume of gas flowing through the fan in unit time; Pressure, also known as wind pressure, refers to the pressure rise value of gas in the fan, including static pressure, dynamic pressure and total pressure; Power refers to the input power of the fan, namely shaft power. The ratio of effective power of fan to shaft power is called efficiency. Centrifugal fan manufactor The total pressure efficiency of fan can reach 90%. Fans are widely used for ventilation, dust discharge and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; Ventilation and induced draft of boiler and industrial furnace; Cooling and ventilation in air conditioning equipment and household appliances; Drying and selection of grain; Wind source of wind tunnel and inflation and propulsion of hovercraft. The working principle of the fan is basically the same as that of the turbine compressor, but because the gas flow rate is low and the pressure changes little, it is generally unnecessary to consider the change of gas specific volume, that is, treat the gas as an incompressible fluid
The wet electrostatic precipitator is a new kind of dust removal equipment used to treat micro dust and micro particles, large Centrifugal fan It 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 atmospheric dust pollution. The wet electrostatic precipitator is usually referred to as WESP, which has the same basic principle as the dry electrostatic precipitator. It goes through three stages: charging, collection and dust removal. The principle of wet electrostatic precipitator is the same as that of dry electrostatic precipitator, Zhangjiajie Centrifugal fan The dust is charged by high-voltage corona discharge, and the charged dust reaches the dust collecting plate/tube under the action of electric field force. The dry electrostatic precipitator mainly deals with dry gas with very low water content, while the wet electrostatic precipitator mainly deals with wet gas with high water content or even saturation. There is a big difference between WESP and DESP in the way of removing the dust collected on the dust collecting plate/pipe. The dry electrostatic precipitator generally uses mechanical rapping or acoustic cleaning to remove the dust on the electrode, while the wet electrostatic precipitator uses regular flushing to remove the dust along with the flow of flushing fluid
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. Zhangjiajie large 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 Centrifugal fan manufactor 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.
Centrifugal fan manufactor Forecast from the characteristics of fan demand. large Centrifugal fan For small and medium-sized fans with large usage and wide range, the product structure and manufacturing process are relatively simple, and the cost is also low. Users mainly pursue high efficiency, low noise, long life, and low price. The other is capital and technology intensive. The product structure is complex, the manufacturing cycle is long, and the completeness and systematicness are also strong. Moreover, it operates under high pressure, high temperature and high speed conditions, and some even operate under severe conditions. Users have different requirements for this type of fan. For turbine blowers, compressors and large ventilators, users mainly pursue high quality, high reliability, smooth operation and long cycle
Gas compression and gas transmission machinery is a machine that converts rotating mechanical energy into gas pressure energy and kinetic energy and transports gas. The main structural components of the fan are impeller, casing, air inlet, support, motor, pulley, coupling, silencer, transmission parts (bearings), etc. large Centrifugal fan The unpowered fan uses the air thermal convection caused by the natural wind force and the indoor and outdoor temperature difference to drive the turbine to rotate, thus using the centrifugal force and negative pressure effect to exhaust the indoor stale hot air. Zhangjiajie Centrifugal fan manufactor The fan is related to the transmission and distribution energy consumption of the system, and is a very critical part of building energy conservation. According to the fan inspection conducted by the National Air Conditioning Equipment Quality Supervision and Inspection Center for many years, many fans have problems under rated conditions, so it is necessary to produce and manufacture fans in strict accordance with product standards. large Centrifugal fan At the beginning of the fan operation, the vibration of the bearing is very small, but with the extension of the operating time, the dust in the fan will be unevenly attached to the impeller, gradually destroying the dynamic balance of the fan, making the bearing vibration gradually increase. Once the vibration reaches the maximum allowable value of 11mm/s of the fan (the maximum allowable value expressed by the amplitude value is as follows), The fan must be shut down for repair (dust accumulation shall be removed and dynamic balance shall be redone). Because it is very dangerous at this time, users must not use it forcibly. When the fan vibration is close to the dangerous value, the vibration measuring instrument will give an alarm.
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.