The harm of long-term low flow operation of centrifugal pump
The hazards of long-term low-flow operation of centrifugal pumps are mainly reflected in the following aspects:
1. Increased temperature of the pump body
Reason: Since the actual flow of the pump is extremely small, that is, the useful work done by the pump is extremely small, and most of the shaft power is converted into heat energy and transmitted to the liquid in the pump, causing the entire pump body to heat up.
Impact: The increase in temperature will accelerate the wear of parts in the pump, reduce the service life of the pump, and may cause other potential problems, such as cavitation.
2. Increased radial thrust
Reason: Under extremely small flow, unreasonable continuous operation will cause the shaft to bend too much, the bearing ring will wear quickly, and even the shaft will break due to excessive fatigue of the shaft.
Impact: This will not only seriously affect the operating efficiency of the pump, but may also cause serious mechanical failures and even paralyze the entire pump system.
3. Surge phenomenon
Performance: When running at a low flow rate for a long time, there will be a phenomenon of regular periodic changes in the flow rate and pump outlet pressure. This phenomenon is called surge. When surge occurs, there will be obvious vibration and sound.
Impact: Surge has an adverse effect on the pump, which will aggravate the vibration and noise of the pump, reduce the operating stability of the pump, and may damage the internal structure of the pump.
4. Reduced efficiency and waste of electric energy
Reason: Long-term low-flow operation causes the actual output of the pump to be far lower than its design capacity, and a large amount of electric energy is wasted on useless work.
Impact: This not only increases the operating costs of the enterprise, but also reduces the energy efficiency level of the entire production process.
5. Other potential problems
Cavitation damage: Long-term low-flow operation is prone to cause cavitation, further damaging the impeller and other key components of the pump.
Shortened life: The operation of the pump under long-term abnormal working conditions will accelerate its wear and aging process, thereby shortening its service life.
Solution
Install the return pipe: Use the return pipe valve to control the actual flow to prevent the pump from running under low flow conditions, so as to achieve the purpose of protecting the pump.
Cut the impeller: Reduce the flow and head range of the pump by cutting the impeller, making it more suitable for operation under low flow conditions. This is an economical and practical method.
Optimize the pump system: Optimize the design and adjustment of the entire pump system to reduce the impact of resistance changes on pump operation.
Regular maintenance: Strengthen regular maintenance and inspection of centrifugal pumps to detect and deal with potential problems in a timely manner.
