Regarding the wind pressure issue of fans
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There is a small L05 type centrifugal fan with the following specifications: power: 0.18kw, speed: 2800rpm, air volume: 360m³/h, total pressure: 550pa. Question: 1. We want to utilize the wind pressure generated by this fan; there is no requirement regarding air volume. The nameplate of this fan indicates a total pressure of 550 Pa, but the wind pressure we need can reach up to 8 kPa. Is it possible to use this fan and increase the wind pressure to 8 kPa by reducing the diameter of the air delivery duct? 2. If the wind pressure can reach 8 kPa, and different wind pressures (such as 8 kPa, 6 kPa, 4 kPa, etc.) are required, what control method would be appropriate? Can using variable-frequency control to adjust the fan speed meet different air pressure requirements?
For this type of small centrifugal fan, the total pressure indicated on its nameplate is 550 Pa; and based on its pressure and flow rate characteristic curves, it is impossible to achieve the desired pressure of 8 kPa, no matter how much pressure is applied
Is this an exhaust fan or an intake fan? Agree with what was said above. If the fan inlet is at atmospheric pressure, even with the fan outlet completely closed, it will not reach the 8 kPa you need. Because the rated wind pressure of the fan is only 0.55 kPa. 8/0.55=14.55; a fan cannot have such a high pressure rise. Adjusting the speed of an inverter-driven motor is a method for adjusting air pressure; adding guide vanes at the fan inlet can also be used. Each fan is suitable only for a specific design range, and its purpose cannot be changed arbitrarily.
The wrong model was chosen; this fan cannot meet the requirements of that operating condition, haha
To reach 8 kPa, a high-pressure blower is needed!
Compared to centrifugal pumps, centrifugal fans have a much flatter performance curve. The pressure rating indicated on the nameplate of your centrifugal fan is only 550 Pa; therefore, it’s impossible for the pressure to reach 8 kPa. You can check the performance curve of this fan to confirm this； Your required wind pressure is 8 kPa, while the air volume is only 360 m3/h. Such a low air volume combined with high wind pressure is generally beyond the capabilities of centrifugal fans; it will be difficult to find a centrifugal fan that meets these requirements. It is recommended that you consider using an eddy current air pump, as it can deliver low flow rates at high pressures.
The outlet pressure of the fan is determined by the system, while whether the fan can provide the required pressure and flow rate is determined by its structural design. For this reason, according to the description, air volume is not required; only air pressure is needed. How can there be air pressure without flow rate? System pressure adjustment actually refers to air volume adjustment. The fan should be selected anew, and the system in which it will operate must be analyzed, taking into account the local natural conditions, in order to properly choose the appropriate model.
Thank you all! This small fan should belong to a blower. Previously, the flow rate of natural gas was regulated using the pressure of compressed air through a gas proportioning valve, but it was later found that fluctuations in the pressure of compressed air (such as when other devices that require compressed air are in operation) caused fluctuations in the natural gas flow rate, thereby altering the air-fuel ratio. To achieve stable pressures under different conditions, an additional fan is added to accomplish this! Question: Is it possible to adjust the ratio of the gas control valve (the original ratio is 1:1), for example by changing it to 1:12?
The difference is too great; it’s simply impossible to meet your requirements
The outlet pressure of the fan is determined by the system, while whether the fan can provide the required pressure and flow rate is determined by its structural design.