Analysis of the factors influencing the efficiency of centrifugal pump package, and measures taken in order to improve pump technical ability and reduce Energy consumption.
I: What are the factors that can influence the efficiency of centrifugal pump package Efficiency of centrifugal pumps is the combination of the technical ability of machinery, volume and hydraulics, and that of pump package is the combination of pump and motor. The following is the main reasons causing a low efficiency of centrifugal pump package?
No.1. The efficiency of pump itself is the elementary factor. Pumps under the same working condition can have very different efficiency.
No.2. Working condition below the level of the allowable one of the pump will cause a low efficiency and a high energy consumption.
No.3. It is of vital importance to choose a high efficient motor since during the functioning, motors efficiency keep almost the same.
No.4. The influence from machinery is related with pump design and manufacturing quality, so after the pump is set, upper management has a small effect.
No.5. Hydraulic loss includes hydraulic friction and partial resistance loss. After some time of working, the surface of impeller and vane etc. will wear out, thus an increase of hydraulic loss and a reduction of hydraulic efficiency.
No.6. Volume loss of pump, also called leakage loss, includes the loss of impeller ring, interstage, 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 lessen.
No.7. Blocking of filter and air suction of line pipe may cause pump evacuation and spinning.
No.8. Before the starting of pump, users should pay enough attention to the preparing job such as warming, turning and pouring into pump, for halfway operation of these basic procedure will often cause cavitations, big noise, loud vibrating and low efficiency.
II: What measure shall we take to ensure a high efficiency of centrifugal pump and a low consumption of energy?
No.1. Change 14 sets of low efficient pump. Choose the pump that has a similar working condition to ensure a high efficiency of the centrifugal pump. The test we conducted shows that the efficiency will increase by 10% after the change.
No.2. Employ the technology of frequency conversion. For pumps whose designing parameter is above the actual working condition, a device of frequency conversion will guarantee a high efficiency of pump.
No.3. Apply new models of motor like permanent magnet, speed adjusting motor and double efficiency motor to the main pumps.
No.4. Mind the choosing of pump. When selecting a new pump, those produced from big companies are preferred in order to ensure a high efficiency.
No.5. Pay attention to the maintenance of pump.
(1) Often check and adjust the bearing seal to reduce volume loss,
(2) After 10,000 hours of working, the pump needs to have a thorough repair to recover efficiency,
(3) Apply sylphon bellows seal to the pump to remove all leakage and ensure a high volume efficiency.
No.6. Clear the filter regularly, check the pipe line connection to make sure an unblocked intaking pipe of the pump.
No.7. Operate seriously according to the procedure. Turn the pump before starting it, open the valve of the intake and close the valve of the discharge to exhaust the air, to make sure whether the intake pressure is eligible. Avoid cavitations of pump due to low pressured liquid supply and insufficient flow rate.
No.8. Exam the efficiency of pump regularly. For low efficient pump, find out the reason timely and then take corresponding steps. When the centrifugal pump transfer the slurry which carries 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 apart the big size media of the slurry from the liquid. And remove the rest slurry and the liquid from the chamber by axial trend, and spurt them to the inlet of pump. Use the material from the pump as the spurt liquid to make eddy current, thus to improve the efficiency of the pump and reduce the abrasion of impeller .