Turning of centrifugal pump impellers
Like any machine, a pumping unit is characterized by power consumption, which determines the required engine power.
The pump power directly depends on pressure and submissions, and is inversely proportional to it efficiency factor (efficiency).
The efficiency of pumping units can vary greatly - from 20% to 98%.
Such a wide range is due to the different nature of the interaction of the working body with the pumped liquid.
General pattern: dynamic pumps (which include centrifugal pumps) are significantly inferior in efficiency to positive displacement pumps.
The significance of this parameter is especially great for large pumps.
One of the effective methods for increasing the efficiency of centrifugal pumps is impeller turning. Selection of the impeller for specific operating modes (flow and pressure) allows, especially on large pumping units, to achieve significant energy savings.
Reducing the impeller diameter - This is indeed a standard procedure recommended in various reference books and operating manuals for pumping units.
The purpose of this procedure: increasing pump efficiency under specific operating conditions.
There are two main options for turning pump impellers:
1. Factory turning:
- If all the necessary operating parameters are known in advance, you can order a pump with an impeller that has already been machined at the factory to the required diameter.
- This allows you to immediately obtain a pump with optimal efficiency for the given conditions.
2. Turning on site:
- If not all parameters are known in advance, then a pump is supplied with the maximum possible impeller diameter for a given model.
- After receiving all the necessary data on operating parameters, the impeller is ground to the required diameter on site.
Advantages of reducing impeller diameter:
- Increased pump efficiency (up to 20% and more);
- Reduced energy consumption;
- Reducing energy costs;
- Reducing the load on the electrical grid;
- Reducing greenhouse gas emissions;
- Increased pump performance.
It is important to note:
- Reducing the impeller diameter can lead to pressure reduction and submissions pump
- Turning of the impeller must be carried out by qualified specialists using special equipment.
- Before turning it is necessary calculate carefully new impeller diameter.
Conclusion:
Reducing the diameter of the pump impeller is an effective way to increase the efficiency of the pumping unit and optimize the cost of pumping liquid.
It is important to choose the right option for implementing this procedure (factory turning or on-site turning) and carefully perform all the necessary calculations.