| 摘要 |
<p>A fan control system for cooling apparatus such as cooling tower in which water and air are brough into contact together. According to this system, the running speed of the fan is continuously and proportionally changed responsive to the termperature of the cooling water or the external atmospheric conditions, to substantially control the cooling capacity of the cooling apparatus. The control system consists of a main fan motor, an electronic adjustment circuit and a power transmission means consisting of a variable pitch diameter belt speed changing means and a constant pitch belt reduction device, whereby the speed changing ratio of the belt speed changing means is continuously and proportionally changed depending upon the control signals from the adjustment circuit. Further, the adjustment circuit may have a soft-start control circuit.</p> |
