Today I will talk to you about the fan and air volume, cold air tower is very much about the fan and air volume, like the fan blade size on the fan efficiency has a great impact, which will also directly affect the blade near the strength of the vortex, which in turn will affect the efficiency of the fan. I will talk to you about which affects the efficiency of the cooling tower.
　　Tests show that the fan blade material, the noise also has a certain degree of influence. For example: the blade of cast aluminium than the blade of stamping steel noise is small; nylon blade than the metal blade noise is small. Generally speaking, the greater the loss factor of the material, the less noise it makes.
　　Increasing the number of blades of a fan can increase the airflow of the fan under the condition that the speed remains the same. Alternatively, the fan speed can be reduced to obtain the same air volume, thus reducing the fan noise. However, increasing the number of blades above 6 results in a limited increase in airflow and often has a negative effect in terms of noise reduction characteristics.
　　Low-speed, wide-bladed fans and high-speed, narrow-bladed fans produce 4dB(A) lower noise pressure levels than the latter at the same airflow and consume 27% less power. Fan noise can be reduced by reducing the gap between the fan and the wind guard to prevent turbulent airflow. Tests show that when the gap is zero, the air volume increased by 27%, while the noise decreased by 3dB (A), reduce the speed so that the air volume back to the original level, the noise can be reduced by 2dB (A).
　　Cooling towers rely on the fan to take the heat away and exhaust into the atmosphere, if the fan airflow is insufficient, it will inevitably lead to the problem of insufficient cooling efficiency. Empty words, tell you a trick, tried and tested, for counter-flow cooling tower, first calculate the cross-sectional area, then multiply by 2.7, and then multiply by 3600 to arrive at the required air volume. Then you buy an anemometer, go to the air outlet to measure, you will understand whether your cooling tower airflow is not enough. For example, a cooling tower that is 3 metres long and 3 metres wide will require an airflow of approximately 3times;3times;2.7times;3600 = 87,480 cubic metres per hour. One problem to note is that when the anemometer measures the air speed at the outlet, there is a lot of air near the wall of the wind cylinder, and near the central hub, there is little air left. This is the case with all axial flow fans. In this case, you need to measure several points from the central hub to the wall of the wind cylinder, and then integrate to calculate the air volume, so as to be accurate.