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.
Forecast the demand structure from the main fields. customized Electrostatic wet precipitator 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. Electrostatic wet precipitator company 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
customized Electrostatic wet precipitator Fans can be divided into axial flow fans, centrifugal fans and diagonal flow (mixed flow) fans according to the flow direction after the airflow enters the impeller. Fans are divided into press in local fans (hereinafter referred to as press in fans) and flame-proof motors placed outside or inside the flow channel, and flame-proof motors placed inside the explosion-proof sealing chamber of the extraction type local fans (hereinafter referred to as extraction fans) according to their purposes. Electrostatic wet precipitator company Fans can also be divided into single-stage, two-stage or multi-stage pressurization fans according to the form of pressurization. For example, 4-72 is single-stage pressurization, and high-end fan is multi-stage pressurization fan. Fans can be divided into axial flow fans, mixed flow fans, roof fans, air conditioning fans, etc. Fan can be divided into negative pressure fan, low pressure fan, medium pressure fan and high pressure fan according to pressure. According to the outlet pressure (pressure rise), it can be divided into: ventilator (≤ 15000 Pa), blower (15-350000 Pa), compressor (≥ 350000 Pa)
How are dust collectors classified, customized Electrostatic wet precipitator Do you know how to distinguish it and how to define its economic type? Let's talk about it from these aspects. 1. Dust removal efficiency. Changsha Electrostatic wet precipitator Dust removal efficiency refers to the ratio of the amount of dust collected by the dust collector to the amount of dust entering the dust collector. According to the total dedusting efficiency, the dedusters can be divided into: low efficiency dedusters (50~80%), medium efficiency dedusters (80~95%) and high efficiency dedusters (more than 95%). 2. Dust removal resistance. The resistance indicates the pressure loss when the airflow passes through the dust remover. According to the resistance, dust collectors can be divided into low resistance dust collectors (Δ P<500Pa), medium resistance dust collectors (Δ P=500 ～ 2000Pa) and high resistance dust collectors (Δ P=2000 ～ 20000Pa). 3. Economy. Economy is one of the important indexes for evaluating dust remover, which includes equipment cost and operation and maintenance cost of dust remover. Among all kinds of dust collectors, the equipment cost of electrostatic precipitator is the highest, followed by bag type dust collector, Venturi tube dust collector, cyclone dust collector is the lowest electrostatic precipitator: the dust removal efficiency is high, generally above 99%, and the design efficiency is up to 99.99%. The wet dust collector is commonly known as "water dust collector" : The filtration efficiency can reach more than 85%, and the integrated desulfurization and dust remover of stone water film+swirl plate>>about 80% of desulfurization and dust removal can reach as high as about 95%.
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. （
