The following two paragraphs illustrate two issues respectively, one issue is the factors that influence the efficiency of centrifugal pump package, and the other is measures that can be taken to improve technical ability and reduce energy consumption.
What are the factors that influence the efficiency of centrifugal slurry pump package?
Efficiency of centrifugal slurry pump is the combination of the technical ability of machinery, volume as well as hydraulics, and the efficiency of pump package is the combination of pump and motor. Major reasons that lead to low efficiency of centrifugal pump package are listed below.
1. The efficiency of pump itself is the elementary factor. Pumps under the same working condition can have different efficiency.
2. Working condition which is below the allowable level of the slurry pump will cause low efficiency and high energy consumption.
3. It is very important to use a high efficient motor, because the motor’s efficiency keeps almost the same during working.
4. The influence of machinery is related with slurry pump design and manufacturing quality, so after the pump is set, upper management has a small effect.
5. Hydraulic loss includes hydraulic friction and partial resistance loss. After some time of working, the surface of impeller, vane and others will be worn out, resulting in an increase of hydraulic loss and a reduction of hydraulic efficiency.
6. Volume loss of slurry pump, also called leakage loss, includes the loss of impeller ring, inter-stage, and axial force balancing organ. The efficiency of volume is related with both pump design and upper management. After a certain time of continuous working, due to friction of every part, the interval will grow and the efficiency will be reduced.
7. Blocking of filter and air suction of line pipe may cause pump evacuation and spinning.
8. Before the starting of slurry pump, users should pay enough attention to the preparing job such as warming, turning and pouring into pump, and incomplete operation of these basic procedures will often lead to cavitations, big noise, loud vibration and low efficiency.
What measures shall we take to ensure the high efficiency and low energy consumption of centrifugal pump?
1. Change 14 sets of low efficient pump. Choose the slurry pump that has similar working condition to ensure the high efficiency of centrifugal pump. The test we conducted shows that the efficiency will increase by 10% after the change.
2. Employ the technology of frequency conversion. For pumps whose designing parameter is above the actual working condition, a frequency conversion device will guarantee a high efficiency of pump.
3. Apply new models of motor like permanent magnet motor, speed adjusting motor and double efficiency motor to the main pumps.
4. Be careful when selecting pump. The slurry pumps supplied by big companies are preferred in order to ensure a high efficiency.
5. The maintenance of pump should be taken seriously.
a. Please check and adjust the bearing seal regularly to reduce volume loss.
b. After 10,000 hours of working, the pump requires a thorough repair which can recover its efficiency.
c. Use sylphon bellows seal to the slurry pump in order to remove all leakages and guarantee the high volume efficiency.
6. Clear the filter regularly, and check the pipe line connection to make sure that the intake pipe is not blocked.
7. Operate the machine according to the procedure carefully. Turn the slurry pump before starting it, open the valve of intake and close the valve of discharge to exhaust the air, and to make sure whether the intake pressure is eligible. Avoid cavitations of pump due to low pressured liquid supply and insufficient flow rate.
8. Detect the efficiency of slurry pump regularly. For low efficient pump, find out the reason in time and then take corresponding steps.
When the centrifugal slurry pump transfers slurry that contains media in big, medium, and small size, it will spurt the liquid into the cylindrical chamber along the tangential effort to make eddy current, and will reject part of slurry from the chamber. It will spurt the slurry into the chamber by axial trend, and the eddy current will separate the big size media in the slurry from the liquid. Then it will remove the remaining slurry and the liquid from the chamber by axial trend, and spurt them to the inlet of pump. The slurry pump is used to transfer the liquid, and the liquid is in eddy form in order to improve the efficiency of the pump and reduce the abrasion of slurry pump impeller.