Installation sequence and skills of desalination centrifugal pump
Desalination centrifugal pump installation sequence
The desalination centrifugal pump must be installed correctly before use. If it is installed incorrectly, the desalination centrifugal pump will be unusable and even damage the centrifugal pump. The installation procedure of the desalination centrifugal pump is shown in the installation sequence diagram of the centrifugal pump. The basic level and elevation should be reviewed before the pump is in place. The centerline and horizontal alignment of the desalination centrifugal pump is the key to the installation process.
Desalination centrifugal pump installation sequence diagram
1. Center line alignment
Centerline alignment is to align the vertical and horizontal centerlines of the pump. First determine the vertical and horizontal center lines on the top surface of the foundation, and then hang vertical lines on the pump inlet and outlet flange surfaces (double-suction centrifugal pump) and the center of the shaft respectively. Adjust the position of the pump so that the vertical line coincides with the vertical and horizontal center lines on the foundation.
2. Level alignment
Horizontal alignment is to align the vertical and horizontal levels of the pump. Generally, the method of using a level gauge or hanging a vertical line, a single-stage centrifugal pump is measured on the pump shaft and outlet flange.
The double-suction centrifugal pump is measured on the inlet and outlet flange surfaces of the pump, and the shim is adjusted to center the bubble of the level gauge, or make the distance from the flange surface to the vertical line equal or coincide with the vertical line. Horizontal double-suction centrifugal pumps can also choose 4 points that can be connected to form a cross on the horizontal open surface of the pump casing. Stand the level ruler on these 4 points, and use the level to read the reading of the level ruler at each point. If the readings are equal, the longitudinal and lateral levels of the pump are aligned at the same time.
3. Elevation correction
The elevation of the water pump refers to the elevation of the axis of the water pump. The purpose of elevation correction is to check whether the elevation of the pump after installation is consistent with the design elevation, and measure it with a level and a level ruler. During the measurement, one level ruler is placed on the known leveling point elevation Hs, and the other level ruler is placed on the pump shaft.
Desalination centrifugal pump installation skills
1. The key to the installation technology of the desalination centrifugal pump is to determine the installation height of the desalination centrifugal pump (i.e. suction). This height refers to the vertical distance from the water surface of the water source to the center line of the impeller of the desalination centrifugal pump. To be confused, the allowable suction vacuum height indicated on the product manual or nameplate of the desalination centrifugal pump refers to the vacuum value on the section of the water inlet of the centrifugal pump, and it is measured under the conditions of 1 standard atmospheric pressure and 20°C water temperature. It does not consider the water flow after the suction pipe is installed. Therefore, the installation height of the desalination centrifugal pump should be the value of the remaining part of the value after the suction height is deducted from the loss head of the suction pipe, and it must overcome the actual topographic suction height. The installation height of the desalination centrifugal pump should not exceed the calculated value, otherwise, the chemical centrifugal pump will not be able to pump water.
2. Reduce pipeline resistance. Therefore, it is advisable to adopt the shortest pipeline layout, and install as few fittings as elbows. It is also considered appropriate to equip water pipes with larger diameters to reduce the flow velocity in the pipes.
3. It should be pointed out that when the elevation and water temperature of the desalination centrifugal pump installation site are different from the test conditions, if the local altitude is above 300 meters or the water temperature being pumped exceeds 20 degrees Celsius, the calculated value must be corrected. That is, the atmospheric pressure at different altitudes and the saturated steam pressure when the water temperature is higher than 20°C. However, when the water temperature is below 20°C, the saturated steam pressure is negligible.
4. From the perspective of pipeline installation technology, the suction pipeline requires strict air tightness, no air or water leakage, otherwise the vacuum at the inlet of the desalination centrifugal pump will be destroyed, and the water output of the desalination centrifugal pump will be reduced, even in severe cases. Can't get water. Therefore, it is necessary to do a good job in the interface of the pipeline to ensure the quality of the pipeline connection.
5. A check valve should be installed at the outlet of the desalination centrifugal pump. In production, sometimes there will be power outages, motor failures and other problems, causing the equipment that is running to suddenly stop. A check valve is installed at the outlet of the centrifugal pump to prevent the liquid in the outlet pipe from being suddenly shut down. Will not flow back into the pump, causing the impeller to reverse and form a water hammer effect, which will damage the impeller and mechanical seal.
