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. （

Wet electrostatic precipitator company In the use of wet electrostatic precipitator, we will encounter problems of one kind or another. If we do not know how to solve them, we will not know what to do. What are the reasons for the failure of wet electrostatic precipitator? Next, I will analyze it for you. （1） large Wet electrostatic precipitator The causes of electrical failure include: electrical components are damaged, corona electrode is not adjusted properly, and porcelain bushing and post insulator through the wall are damaged. ① The electrical components are damaged, such as the fuse is blown, the high-voltage silicon rectifier tube is broken down or the thyristor is damaged, which can lead to the power failure; If the milliammeter is damaged or the transformer fails, the phenomenon of fault type (3) will occur. ② If the nickel chromium alloy wire is not used, the corona electrode will be rusted and broken after being used for a short time. The tension of corona wire is uneven, the force is uneven, and the overload of individual corona electrode will also cause the corona electrode to break; If the corona electrode is not installed in place, deviates from the center of the settling tube, or has too much scale, the electric field will flash over frequently, or even the operation will be interrupted. ③ If the mechanical properties of the through wall porcelain bushing and post insulator are not up to standard and cannot bear the tension of the upper and lower hangers, the insulator will be damaged and cracked. The insulator box temperature control is unreasonable, and the temperature is low or changes violently, which will also cause the insulator to be damaged and cracked; Excessive scale on the surface of insulator will also cause damage and crack of insulator. The final result is that the electric field is grounded, the operation of the electrostatic precipitator is interrupted, and faults (2) and (4) occur.

When the bearing temperature of the fan is normal, it is ≤ 70 ℃. If it rises to 70 ℃, an alarm should (will) be given if there is an electric control. At this time, the reason should be found out. First, check whether the cooling water is normal? Is the bearing oil level normal? If the cause cannot be found for a while, the bearing temperature rises rapidly to 90 ℃, and if there is an electric control, the alarm and shutdown signal shall be sent again. River pool Wet electrostatic precipitator In the process of fan startup, shutdown or operation, if any abnormal phenomenon is found, it shall be checked immediately. If any small fault is found during the check, it shall be timely found out the cause and eliminated. In case of major fault (such as severe vibration, impact of fan, sharp rise of bearing temperature, etc.), stop the machine immediately for inspection. large Wet electrostatic precipitator The lubricating oil (or grease) shall be renewed and replaced one month after the first operation of the fan. In addition to replacement after each overhaul, the lubricating oil (or grease) can be replaced once every 1~2 months under normal conditions, or according to the actual situation. Fans include fans, turbine blowers, roots blowers and turbine compressors, which are divided into seven categories in detail, including centrifugal compressors, axial compressors, centrifugal blowers, roots blowers, centrifugal fans, axial fans and Ye's blowers

Main factors affecting the dust removal efficiency of wet electrostatic precipitator. The effect of electrostatic voltage, water volume and dust concentration on wet electrostatic precipitation efficiency is positive, that is, the dust removal efficiency increases with the increase of voltage, water volume and dust concentration. Among them, voltage has the most significant effect on dust removal efficiency, followed by water volume, and dust concentration has the least effect. The combination of static electricity and water mist can significantly improve the dust removal efficiency. The role of water in wet electrostatic precipitation. The water in wet electrostatic precipitator mainly exists as atomized water droplets. According to domestic research, water mist has a series of effects on the improvement of dust removal efficiency of wet electrostatic precipitator, large Wet electrostatic precipitator Main mechanism: the water mist can keep the discharge electrode clean and keep the corona vigorous; The mist particles strike the dust collecting electrode to form a thin and uniform water film, River pool Wet electrostatic precipitator It can prevent the "secondary flying" of low specific resistance dust from tempering high specific resistance dust and prevent the occurrence of "reverse corona"; For the dust with strong viscosity, the electrode can be prevented from sticking; It is also suitable for collecting those flammable and explosive dust. The water mist is sprayed directly to the discharge electrode and corona area, and the discharge electrode also acts as an atomizer. The same power supply can realize corona discharge, water atomization, water mist and dust particle charging, realizing the organic combination of static electricity and water mist. The water mist is directly sprayed to the discharge electrode, which has a high charge. The collision interception, adsorption and coagulation of water mist with high charge mass ratio in the electric field can greatly improve the dust removal efficiency. The water mist strikes the dust collecting electrode to form water flow down, so that the dust collecting electrode is always kept clean, eliminating the vibrating device, and avoiding a series of problems caused by vibrating dust removal in dry dust removal. In the method of spraying water mist to the discharge electrode and corona area to further atomize the water mist, the static electricity does not directly contact the spray device, so there is almost no insulation problem. This method is completely different from the dedusting technology of "corona discharge atomizes water". The latter is almost impossible to insulate due to the direct contact between water and electricity, and it is actually difficult to achieve industrial application. The barbed electrode can produce a strong electrostatic field, and has a good corona discharge capacity. The electrostatic and water mist work together, and has a high dust removal efficiency

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 Wet electrostatic precipitator 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. River pool Wet electrostatic precipitator 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 Wet electrostatic precipitator 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.