The operation process of the flow regulation method of the submersible sewage pump

Many friends about the submersible sewage pump has a problem, that is, what is the method of flow regulation, the following is to tell you about the specific operation process.

1. Outlet throttling: For low and medium RPM pumps, this is a common and inexpensive method of flow regulation. Throttling critical dead point may cause the fluid in the pump to overheat, can be used to maintain the necessary flow by bypass, or with different means of regulation. This is very important for the pumps that handle hot water or volatile liquids mentioned earlier.

2, suction inlet throttling: if sufficient NPSH can be utilized, then some power can be saved by throttling in the suction line. Inlet throttling is often used in jet engine fuel line pumps because outlet throttling can cause overheating or vaporization of the liquid. At very small flows, the impeller of these pumps is only partially filled with liquid. Therefore, when the input power and temperature rise are about outlet throttling, the flow of the condensate pump at 1/30 of the impeller's full operating capacity is usually controlled by the submersive depth 7, which is equivalent to the inlet throttling. Special designs can reduce the cavitation damage of these pumps to the point of insignificance, but the energy level is also considerably lower.

3, bypass regulation: the discharge line from the pipeline pump can be shunted out of all or part of the flow, through the bypass pipe to the pump suction or other appropriate points. One or more flow orifice plates and appropriate control valves can be installed in the bypass. Metering bypass is usually used to reduce the flow of the boiler feed pump, mainly to prevent overheating. Considerable power savings can be achieved if the excess flow of the bypass paddle pump is substituted for the outlet throttling.

4, speed adjustment: using this method to adjust the flow, can make the required power is reduced to a small, and can eliminate the flow in the process of overheating. Steam turbines and internal combustion engines can be easily adapted to speed regulation at a small additional cost. All kinds of mechanical, magnetic, hydraulic, and DC and AC variable speed motors can be used to adjust the speed. In general, variable speed motors are too expensive and adjustable blades should only be used when economic studies of special cases prove worthwhile.

5. Air replenishing: Air replenishing to the suction inlet of the pipeline pump is also a way to regulate the flow rate. This method can save some power compared with the outlet throttling. Usually, you do not want air in the liquid being delivered, and there is always a risk that too much air will cause the pump to lose its filling head, so this method is rarely used in practice except on rare occasions.