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Centrifugal pump of common classification with the use of 8 big errors
Published time :2011-8-20  Hit:12194

Centrifugal pump is the most widely used water pumps, centrifugal pump impeller, according to the number of working pressure, impeller, pump shell with water inlet means slit forms, pump shaft, impeller position out of the water to the pressure chamber into the way of six different categories. And because of his use of universality, that has to be said that the centrifugal pump during use of the 8 big errors.

Centrifugal pump using the error in

Use of a centrifugal pump in a misunderstanding: the pump for low lift pumping

A lot of machine hand think pumping lift is lower, the load of the motor is small. In this kind of wrong understanding to mislead, choose the pump when the pump head, often will be chosen very high. In fact, the centrifugal water pump, when the pump model is determined, the power consumption is the size of the pump and the actual flow rate proportional to the. While the pump flow rate with the lift increases, so the head is higher, the flux is small, the power consumption is small. Conversely, the lower the head, flow rate, power consumption is bigger. Therefore, in order to prevent overload of the motor, general pump s actual pumping using head shall not be less than the head of the 60% calibration. So when high lift for low lift pumping, the motor is easy to overload and fever, serious when can burn motor. If the emergency use, it must be arranged on an outlet pipe of a water discharge valve for regulation, to reduce the flow, preventing motor overload. Attention to motor temperature rise, if the motor overheat, should be timely close the outlet flow or shutdown. It is also prone to misunderstanding, some machine hand that clog the outlet, forced to reduce flow, will increase the load of the motor. In fact, on the contrary, the formal power of centrifugal pump irrigation and drainage water outlet pipe is provided with a valve unit, in order to reduce the unit when starting the motor load, first close the valve, the motor starts to gradually open the valve is the truth.

Use of a centrifugal pump in zone two: large diameter pump with small water pumping

A lot of machine hand that this can improve the actual lift, but the actual pump head = total lift - lift loss. When the pump model is determined, the total lift is certain; lift loss mainly comes from the pipe, the diameter of the smaller resistance is obviously, so the lift loss is bigger, so reducing the diameter, the really pump lift can not only increase, but will be reduced, causing the pump efficiency. Similarly, when a small diameter pipe pump for pumping, will not reduce the really pump lift, but because of pipe resistance decreases the loss of lift, the lift has increased. Also organic hand think small diameter pipe pump for pumping, will significantly increase the load of the motor, they think the pipe diameter is increased, the water in the water outlet pipe of the pump impeller pressure is large, thus greatly increasing the load of the motor. However, only the size of liquid pressure and lift of the pipe, and the cross-sectional area size. As long as the head, pump impeller size unchanged, no matter how much role in the impeller diameter, the pressure is certain. Just after the diameter increases, the flow resistance can be reduced, and the flow rate is increased, the power consumption is increasing. But as long as the rated head range, no matter how increased diameter pump is working, and can also reduce the line loss, improve the efficiency of water pump.

Use of a centrifugal pump in Zone Three: installation of water inlet pipe, horizontal section or to the source direction of upturned

Doing so will make the water inlet pipe aggregation air, reduce water pipes and pumps vacuum degree, so that pump water head decreases, water reduction. The correct approach is: the horizontal section to the water is slightly oblique, should not be level, but not up.

Use of a centrifugal pump in zone four: the water inlet pipeline with more elbow

If the water inlet pipe with the elbow, increases the local flow resistance. And the elbow should be in the vertical direction is not allowed in the horizontal direction turning, turning, so as to avoid the accumulation of air.

Use of a centrifugal pump in Zone Five: water inlet of the water pump is directly connected with the elbow

This will make the water flow through the elbow into the impeller of the uneven distribution of. When the water inlet pipe diameter is larger than the water inlet of the water pump, should be installed eccentric reducer. Eccentric reducer pipe plane part to be mounted on, sloping part installed in the following. Otherwise the aggregation of air, to reduce the amount of water or pumping water, and a crash. If the water inlet pipe and the water inlet of the water pump of equal diameter, should be in the pump inlet and the elbow pipe between the straight pipe length, shall not be smaller than the pipe diameter of 2 ~ 3 times.

Use of a centrifugal pump in Zone Six: a valve inlet pipe of the section is not vertical

If this installation, the valve can not be closed, causing water leakage. Correct installation method is: is provided with a bottom valve in the inlet pipe, the lower section is preferably perpendicular. As a result of topographic conditions cannot be installed vertically, then the pipe axis and horizontal plane intersection angle should be more than 60 degrees.

Use of a centrifugal pump in zone seven: water inlet of the water inlet pipe position.

( 1) water inlet of the water inlet pipe from the water inlet at the bottom of the pool and pool wall a distance less than the inlet diameter. If the pool bottom sediment and dirt, water from the pool bottom distance less than 1.5 times the diameter, the water will cause poor or sucked into the silt sundries, blocking water inlet.

( 2) water inlet of the water inlet pipe into the water depth is not enough, it will cause water inlet pipe around the water surface vortex, affect the water, reduce water. The correct installation method is: medium and small water pumps in water depth of not less than 300 ~ 600mm, 600 ~ 1000mm of large water pump shall be not less than.

Use of a centrifugal pump in zone eight: the outlet pipe in the tank above the normal water level

If the outlet in a pool of normal water level of above, although increased pump head, but a decrease in flow. As a result of terrain conditions, the outlet must be high out of the pool water level, should be installed in pipe elbow and pipe, the pipe into siphon, reduces the height of outlet.

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