large Axial flow centrifugal fan The fan is a kind of driven fluid machinery, which relies on the input mechanical energy to increase the gas pressure and discharge gas. Fan is the abbreviation of Chinese custom for gas compression and gas transmission machinery. Generally speaking, fans include fans, blowers, and wind turbines. Guangdong Axial flow centrifugal fan company Fans are widely used for ventilation, dust discharge and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings, as well as ventilation and induced draft of boilers and industrial furnaces; Cooling and ventilation in air conditioning equipment and household appliances; Drying and delivery of grain, wind source of wind tunnel and inflation and propulsion of hovercraft
Among all kinds of mechanical and electrical equipment in all walks of life in China, the motors matched with fans account for about 60% of the installed capacity of national motors, and the power consumption accounts for about one-third of the total power generation in China. In particular, Axial flow centrifugal fan company Most fans have the phenomenon of pulling a cart from a horse during use. In addition, due to changes in production and technology, it is necessary to frequently adjust the gas flow, pressure, temperature, etc; Many units still adopt the backward way of adjusting the opening degree of the wind shield or valve to adjust the gas flow, pressure, temperature, etc. In fact, this is to meet the requirements of process and working conditions for gas flow regulation by artificially increasing resistance at the cost of wasting electric energy and money. This backward regulation mode not only wastes valuable energy, but also has poor regulation accuracy, which is difficult to meet the requirements of modern industrial production and services, and has serious negative effects. With the continuous improvement and development of frequency conversion technology in recent ten years. The performance of variable frequency speed regulation is becoming increasingly perfect, large Axial flow centrifugal fan It has been widely used in AC speed regulation in different fields. It has brought considerable economic benefits to enterprises and promoted the automation process of industrial production.
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. Axial flow 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 Axial flow 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.
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 Axial flow 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. Guangdong Axial flow centrifugal fan company 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 Axial flow 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.
The use of wet electrostatic precipitators is becoming more and more common. How much do you know about the equipment? Today, I'm going to popularize knowledge for you and talk about the advantages and disadvantages of wet electrostatic precipitator. Let's learn together. Advantages of electrostatic precipitator High purification efficiency, capable of spreading fine particles of more than 0.01 microns. In the design, different operating parameters can be used to meet the required purification efficiency. ⑵ The resistance loss is small, generally below 20 mm water column. Compared with cyclone dust collector, the total power consumption is small even considering the power consumption of power supply unit and rapping mechanism. ⑶ Guangdong Axial flow centrifugal fan The allowable operating temperature is high. For example, the allowable operating temperature of SHWB type circuit dust collector is 250 ℃. Other types can reach 350~400 ℃ or higher. ⑷ Large gas processing range. ⑸ large Axial flow centrifugal fan Automatic operation control can be fully realized. Disadvantages of electrostatic precipitator The equipment is relatively complex, requiring a high level of equipment allocation, installation and maintenance management. ⑵ There are certain requirements for the specific resistance of dust, so there is a certain selectivity for dust, which can not make all dust obtain high purification efficiency. ⑶ It is greatly affected by the operating conditions such as air temperature and temperature. If the same kind of dust is operated at different temperatures and humidities, the results will be different. Some dust can work well at a certain temperature and humidities, but the ESP can hardly be used at another temperature and humidities due to the change of dust resistance. ⑷ Axial flow centrifugal fan company The primary investment is large, and the horizontal electrostatic precipitator covers a large area. ⑸ At present, the practical effect in some enterprises can not meet the design requirements.