The 11-62 centrifugal fan is a high-efficiency, variable speed, low-noise centrifugal fan. It is composed of an advanced aerodynamic impeller, a logarithmic spiral casing, an adjustable speed internal external rotating motor, an arc-shaped air inlet and other components. The unit can achieve stepless speed change (0% ~ ), and has the characteristics of novel and compact structure, low vibration, and easy use and adjustment.
Application
It can be used as both input gas and output gas for indoor ventilation of general factories and buildings and is more suitable for variable air volume systems. The types of gas transported are air and other non-self-igniting and harmless gases to the human body. The gas must not contain sticky substances, and the dust and hard particles contained must not exceed 150mg/m3. The temperature of the gas must not exceed 80 ℃.
Type
The 11-62 centrifugal fan has five machine numbers (No.): 2.5, 3, 3.5, 4, and 4.5. It can be made into two types: right-handed and left-handed. When viewed from the motor end, the impeller rotates clockwise, which is called a right-handed fan, represented by "right"; when it rotates counterclockwise, it is called a left-handed fan, represented by "left". The fan outlet position is made into three movable 0°, 90°, and 180°, which can be adjusted. Please indicate when ordering.
Structure
The 11-62 type centrifugal fan is mainly composed of impeller, casing, air inlet, and motor.
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Impeller: It is made of 72 forward thin arc blades riveted with a wheel disc and a wheel cover. They are all made of aluminum plates and have been calibrated for dynamic and static balance. It has good air performance, high efficiency, low noise, and stable operation.
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Casing: It adopts a steel plate welded integral structure, and the unit is easy to install.
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Air Inlet: Installed on both sides of the fan, the section parallel to the axial direction is a streamlined section, which enables the air flow to enter the impeller smoothly with less loss.
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Electric Motor: The rotor is fixed, and the impeller is installed on the motor housing and is directly driven by the rotation of the motor housing. The motor adopts soft characteristics and can evenly adjust the fan speed with the help of a three-phase voltage regulator to meet the changing requirements of the system load.
Performance and selection
Fan performance generally refers to the performance under standard conditions. Regardless of the performance required by technical documents or ordering, except for special orders, the standard conditions shall prevail. Therefore, when the use state is non-standard, it must be replaced according to the relevant formula. The network characteristics and the deviation of the total pressure and the relationship between the flow rate are calculated as the performance under standard conditions, and then the selection is made according to the performance table.
Treatment of Excessive or Insufficient Flow
During use, excessive or insufficient flow often occurs. There are many reasons for this phenomenon. If the flow rate is sometimes large and sometimes small during use, it is mainly due to the resistance in the pipe network, or the fan is working in the flying area. If the flow rate gradually decreases after a long time during use, it is mainly due to pipe network blockage.
After the fan is newly installed, the flow rate may be too large or too small when it is officially put into operation. The reasons for this phenomenon are as follows:
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The actual value of the pipe network resistance differs greatly from the calculated value. Calculated by the general pipe network characteristic equation: p=Kq2. If the actual value K of the resistance coefficient is less than the calculated value K, the flow rate increases; if the actual value K is greater than the calculated value K, the flow rate decreases, see the relationship diagram b between the deviation of the pipe valve characteristics and the total pressure and the flow rate.
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The influence of the fan's total pressure deviation Δp was not considered during selection. When the fan's actual total pressure has a positive deviation, the flow rate increases, and when it has a negative deviation, the flow rate decreases. See the relationship between the pipe network characteristics and the total pressure deviation and flow rate in Figure a.
