Selection and application of fan performance (I) Description of fan performance: 1. № 10, 12, 16, 20 are converted according to dimensionless performance of № 10 model. 2. № 5, 6, 8 are converted according to dimensionless performance of № 5 model. 3. № 5 and below shall be determined according to the performance of the measured prototype. Note: According to the dimensionless performance curve conversion formula, total pressure H=ρ u2 H (Pa) flow Q=900 π D22 uQ (m3/h) shaft power N=N × D22u3 ρ/4000 (kw), where D2 - impeller outer diameter (m) u - impeller outer edge linear speed (m/s) ρ - gas density (Kg/m3), the required power rate shall be based on shaft power plus mechanical loss and motor reserve. 4. The solid line is № 5 model, and the dotted line is № 10 model. The performance of the fan is expressed by the flow, total pressure, main shaft speed, shaft power, efficiency and other parameters of the fan, and there are certain relationships between the parameters, which are listed in the following table. The relationship of fan performance parameters changes density ρ, speed n changes speed n, atmospheric pressure P, gas temperature t Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 ρ 1/ρ 2 N1/N2=(n1/n2) 3 ρ 1/ρ 2 η 1=η 2 Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 (P1/P2) (273+t2/273+t1) N1/N2=(n1/n2) 3 (P1/P2) (273+t2/273+t1) η 1=η 2 Note: 1. In the middle, Q represents flow (m3/h), H represents total pressure (Pa), N represents shaft power (kw), η represents full pressure efficiency, ρ represents density (kg/m3), t represents temperature (℃), n represents speed (r/min), and P represents atmospheric pressure (Pa). 2. The footnote symbol 2 indicates the known performance and related parameters, and the footnote symbol 1 indicates the required performance and related parameters. （
The wet electrostatic precipitator is mainly used to purify water vapor, odor, acid mist and other harmful substances in the exhaust gas discharged by the factory. As an air pollution control equipment, it has also been widely used. let's Boiler fan manufactor Understand its system composition together. 1. Composition of wet electrostatic precipitator system. According to its working principle, the control system of wet electrostatic precipitator generally includes high pressure system, water treatment system, low pressure heating and hot air purging system, upper computer system, etc. 2. Design of wet electrostatic precipitator system. (1) large Boiler fan High voltage system and wet electrostatic precipitator charge the dust through corona discharge of high voltage system. The charged dust reaches the dust collecting plate under the effect of electric field force, and then the dust is removed by regular scouring. (2) Qiandongnan large Boiler fan Water treatment system. This system deals with the problem of secondary water pollution. It is mainly the water discharged after equipment spraying and flushing, which contains a lot of acid substances and fine particles. Direct discharge will cause secondary pollution. The recycling of water in the equipment consists of two steps: neutralization and acid removal, and separation of suspended solids, so that the sewage can be turned into industrial water suitable for spraying. (3) Heating system. The heating system includes insulator incubator heating, hot air purging heating, and the hot air purging system is composed of fan, butterfly valve and heater. When it starts actively, it starts in the order of fan, butterfly valve and heater. When actively closing, it shall be closed in reverse order. (4) Upper computer system. The selected upper computer system is an industrial control computer, and the network front-end computer is used to enable the system to have extraordinary data acquisition and processing capabilities, so as to meet the requirements of wet electrostatic precipitator for centralized management, decentralized control, energy conservation and emission reduction.
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 Qiandongnan Boiler 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 Boiler 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 Boiler fan manufactor 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.
The selection basis of wet dust collector is as follows. ① large Boiler fan Dust removal efficiency. Whether the efficiency of wet dust collector is high or not is one of the most important performance indicators to be selected. Under certain conditions, the gas flow, specific dust pollutants, and the gas state have a direct impact on the collection efficiency. ② Operational flexibility. Boiler fan manufactor Any operating equipment shall consider its negative flow, and the impact on the capture efficiency when the air flow exceeds or is lower than the design value; Similarly, it is necessary to know how to operate when the dust concentration is unstable or continuously higher than the design value. ③ Hydrophobicity. The purification efficiency of wet dust collector for hydrophobic dust is not high, and generally it is not suitable for the operation at the design value. ④ Adhesion. Wet dust collector can purify cohesive dust, but flushing and cleaning shall be considered to prevent blockage, ⑤ corrosiveness. Anticorrosion measures shall be considered when purifying corrosive gas, ⑥ water consumption. How much water is consumed by the dust remover, sewage treatment and anti freezing measures for water in winter. ⑦ Mud treatment. Mud treatment is an inevitable problem for wet dust collectors, and efforts should be made to reduce the harm of pollution. ⑧ Operation and maintenance. Qiandongnan Boiler fan manufactor Generally, moving or rotating parts inside the dust remover shall be avoided, and it shall be noted that if the gas passes through the channel section too small, it will cause blockage.
Forecast the demand structure from the main fields. large Boiler fan General ventilation fans (generally small and medium-sized centrifugal and axial fans) are the most widely used, with the largest demand and the largest number of manufacturers. In general, the supply of such products exceeds the demand. Although the demand for special purpose fans (including anti-corrosion fans, high-temperature fans, wear-resistant fans, fire smoke exhaust fans, etc.) is not large, due to the special operating environment, they need to be treated differently, because the main material requirements are special. The biggest feature of Roots blower is that when the pressure is adjusted within the allowable range, the flow changes little, the pressure selection range is wide, and it has the characteristics of forced gas transmission. The main disadvantage is that the noise is large. Boiler fan manufactor Through technology introduction, joint venture and self-development, China has launched a three blade roots blower with low noise, which is very popular with users and has a good market prospect. Turbine compressor (including centrifugal compressor, axial compressor and axial centrifugal compound compressor) is an important equipment of major engineering complete equipment, which plays an important role in the national economy. The performance of turbine compressor requires high pressure and large flow. With the large-scale of the complete set of equipment, the turbine compressor parameters are required to be higher and higher. Such as blast furnace smelting plant, large coal chemical plant, large fertilizer plant, large ethylene plant, large air separation plant, natural gas pipeline transportation plant and oil field gas injection plant. The demand for such products accounts for a small proportion of the total fan volume, but because of their importance, complex structure, long manufacturing cycle and high technical content, they have relatively good economic and social benefits. Turbine compressor manufacturing level represents the overall level of the fan industry
9. Since the flow, total pressure, main shaft speed and shaft power of the fan have a fixed relationship, the main shaft speed should not be changed when the motor capacity does not change. If the main shaft speed increases, the motor may be burned due to overload. The motor power used by the fan refers to the power not required when the air inlet and outlet are fully open in terms of mechanical losses and due reserves under a specific mine. If the outlet or inlet of the fan is not connected to the pipeline or is idle without external resistance, the motor may also be burned out. For safety, a valve shall be added to the outlet or inlet pipeline of the fan, and it shall be closed when starting the motor. After turning, the valve shall be slowly opened until the specified working condition is reached, and attention shall be paid to whether the current of the motor exceeds the specified value. High power motors must be started in proper ways, such as voltage reduction, frequency conversion, etc.
