Pump selection help?
Thread Content
This post was last edited by lauhob on 2009-11-28 15:57 Now the centrifugal pump here cannot transport at all because of the high temperature of the medium. We first require the selection of a pump that can meet this working condition. Please give some advice to the moving equipment experts! Working conditions: About 90 degrees water original centrifugal pump parameters: The Yang distance is 60m and the flow rate is 180m3/H. Originally, the centrifugal pump meets the conditions for use. However, another channel of water is introduced, which increases the water temperature in the pool and causes the medium in the pump to be close to vaporization, so the centrifugal pump cannot be measured at all. Are there other types of pumps, or pumps that can meet such conditions? Experts, I need your advice!
This post was last edited by netcraft on 2009-11-30 11:23. What were the original conditions? There is no problem with the centrifugal pump pumping hot water. There is no need to correct the cavitation margin for hot water. The extra NPSH can be regarded as an additional safety margin. (API recommendation). Above 80 degrees, the mechanical seal should be flushed using the 23°C method because the lubricity of high-temperature water is reduced and the mechanical seal is easily worn.
The temperature of 90 degrees is not very high. Why is it so easy to vaporize? I think the cavitation margin of the device is not large enough. I suggest that adding an inducer is the best way.
This post was last edited by hcwang12345 on 2009-11-30 22:33. If the water temperature in the pool is 90 degrees and the saturated vapor pressure is 0.0701MPa, what is the local atmospheric pressure? Even if the local atmospheric pressure is 100kPa, the cavitation margin is less than 3m. According to the specifications of your pump, if you choose a high-speed pump (2900rpm,) the necessary cavitation margin should be about 5m. To solve this problem: Give some immature opinions: 1. Choose a low-speed hot water pump. For the same water pump, when the speed changes, the cavitation margin must be proportional to the square of the speed. Therefore, the anti-cavitation ability of the pump will be greatly deteriorated after the speed is increased. If a low-speed pump is selected, the cavitation resistance will be improved. ； 2. Is it possible to increase the filling height or lower the installation position of the pump? ； 3. Increase the diameter of the water pump inlet pipe to reduce resistance loss. ；
Evaporation of the pump medium indicates insufficient inlet pressure. Just increase the inlet pressure.
Please friends upstairs please describe in detail!
Please discuss with your craftsman to see if there is any other good way to solve the problem of high medium temperature. What you said upstairs should be to increase the inlet pressure head, such as pressurization.
It is recommended to use a high-temperature submersible pump. We use a submersible pump for steam condensate. You don’t have to worry about the quantity. However, when choosing, pay attention to the material and structure of the submerged part.