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 total 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 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.

Yunnan large Boiler centrifugal fan WESP has the advantages of high dust removal efficiency, small pressure loss, simple operation, low energy consumption, no moving parts, no secondary dust, low maintenance costs, short production downtime, can work below the flue gas dew point temperature, can be combined with other flue gas treatment equipment due to its compact structure, and diversified design forms. The wet electrostatic precipitator uses liquid to wash the dust collecting electrode surface for dust removal, which can effectively collect fine particles (PM2.5 dust, SO3 acid mist, aerosol), heavy metals (Hg, As, Se, Pb, Cr), organic pollutants (polycyclic aromatic hydrocarbons, dioxins), etc. After the wet electrostatic precipitator is used, the smoke and dust emission in the wet flue gas can reach 10mg/m3 or even below 5mg/m3, and the dust collection performance has nothing to do with the dust characteristics, Boiler centrifugal fan Price It is suitable for the treatment of wet flue gas, especially for the treatment of dusty flue gas after wet desulfurization in power plants and steel plants. However, the equipment investment cost is high, and it needs to be used together with other dedusting equipment. Its investment, technical economy and operating cost should be evaluated from an overall perspective.

Emergency stop: large Boiler centrifugal fan Price In case of one of the following situations during the unit commissioning, emergency shutdown shall be carried out immediately. The emergency stop operation is to press the stop button of the main motor, and then carry out the remedial work after the shutdown; The centrifugal fan suddenly vibrates strongly and has exceeded the trip value; There is scratch or abnormal friction sound inside the machine body; large Boiler centrifugal fan Smoke occurs at any bearing or seal, or the temperature of a bearing rises sharply to the alarm value; When the oil pressure is lower than the alarm value and cannot be restored to normal; The liquid level in the oil tank is low, and there is suction phenomenon; When the axial displacement value increases significantly and reaches the alarm value;