Two misunderstandings in the use of centrifugal explosion-pr

Two misunderstandings in the use of centrifugal explosion-proof oil pump:

1, high head pump for low head pump station

Many cards, lower head, smaller motor load.

In this misunderstanding, when buying oil pumps, pumps tend to choose high head.

In fact, for centrifugal pump, when determining the type of pump, the power consumption is proportional to the actual flow of the pump.

The pump flow rate will increase with the head decrease, so the head increase will reduce the flow rate and smaller power consumption.

On the contrary, under the head, greater flow, greater power consumption.

Therefore, in order to prevent motor overload when pumping the actual use of the elevator overall requirements cannot calibrate the head less than 60%.

Therefore, when high head and low head pumping, the motor overload, easy to heat, serious can burn the motor.

If used in an emergency, it must be installed in the outlet pipe to regulate the water discharge gate valve (or wood and other materials blocking the small outlet) to reduce flow and prevent motor overload.

Note that the temperature of the motor rises. If the motor overheats, turn off the small outlet flow or shut off in time.

This is also prone to misunderstanding, some mobile phones think that blocking the exit, forced to reduce the flow, will increase the motor load.

In fact, on the contrary, regular large power supply centrifugal explosion-proof pump drainage irrigation drainage units are equipped with gate valves, in order to reduce the unit start motor load, the gate valve should be closed first, the motor began to gradually open the gate valve is this reason.

2. Large diameter oil pump and small oil pump

Many hands, can improve the actual head, in fact, the actual head = total head loss.

When the pump model is determined, the total head is certain;

The loss of the head is mainly caused by the pipeline resistance. Obviously, the greater the resistance of the smaller diameter, the greater the loss of the larger head. Therefore, when the diameter is reduced, the actual pump can not only be increased, but will be reduced, leading to the reduction of the efficiency of the pump.

Similarly, when a large pipe with a small diameter is pumped, it does not reduce the actual pump head, but instead reduces the resistance of the pipe to reduce the loss of the magnetic head, thus increasing the actual head.

But there are also machine hands, small diameter of the large pipe pumping pump, which will greatly increase the motor load, they think that the diameter increase in the large pump impeller pressure pipe, which will greatly increase the motor load.

It is known only to be related to the head of the horizontal liquid pressure, size, and has nothing to do with the size of the cross sectional area of the tap.

As long as there is a certain elevator, the pump impeller size is the same, no matter how big the diameter, the role in the impeller pressure is certain.

However, with the increase of diameter, the water resistance will decrease, and the increase of flow will also increase the power consumption.

But as long as the rated head range, no matter how to improve the diameter of the pump can work, and can also reduce pipeline loss, improve the efficiency of the pump.