Deep well pump selection method

Selection of Deep Well Pumps (1) Select a multi-stage submersible pump based on the maximum allowable extraction volume of the source well. The pump's pumping volume must be consistent with the actual water inflow in the well. The pumping capacity must be equal to or slightly less than the actual extraction volume of the source well, otherwise strong pumping will inevitably occur, which will not only shorten the service life of the deep well submersible pump, but will also filter The net has been destroyed, causing the gushing of sand to continue, even causing the well to be scrapped.

(2) The diameter of the deep well submersible pump must be consistent with the diameter of the wellbore. In order to make the deep well pump get off smoothly, the groundwater can quickly collect space when pumping water, and the resistance of the pump can also be reduced without the resistance. The diameter of the wellbore of the lift pipe and the pump body should be larger than the maximum diameter of the pump body by 20-40 mm. That is, the annular gap between the largest diameter part of the pump body and the borehole wall must be 10-20 mm in order to extend the service life of the submersible pumps in wells and deep wells.

(3) Deep well submersible multi-stage pump head down well position The pump head of the deep well submersible pump must not be placed in the position of the filter tube (flower tube), but must be placed in the well wall tube (real tube) position, otherwise it will surge when pumping. Sand will not stop or destroy the well. According to the interpretation of the electric measurement curve of the exploration hole, it is decided by both wells A and B according to the hydrogeological conditions (buried depth of the aquifer, aquifer thickness, aquifer lithology) and pump operation conditions of the well and adjacent water wells. The well's well structure (well diameter, manifold, real pipe location), well completion depth, and pump selection ensure that no problems occur in the future when the pump and pump are running.

(4) According to the allowable exploitation amount of the water source well, select the deep well submersible pump, determine the specifications and type of the deep well submersible pump according to the water inflow, and determine the reasonable structure of the water source well under the conditions allowed by the hydrogeology.

(5) Select the deep well submersible centrifugal pump according to the total head loss. According to the deep well submersible pump to pump the groundwater from the pump head to the ground pool or water tower, the total head loss required to select the deep well submersible pump diameter, head (stage) and power. Water pressure increases in proportion to the number of impellers flowing through it. The deep well pump's impeller is immersed in water and only lifts without suction. The rated head and the actual operating head of the pump must not differ too much and must not be higher than 25% of the actual head. The high pump lift, the required motor power, easy to cause the pump to have a larger string, the light wear the impeller and the leaf shell, the weight of the bearing in the shell (from the limit role) easy to stick with the pump coupling, Causes the pump not to run and the motor overload winding will burn out. If a high-lift pump is used for low head pumping, the flow rate will inevitably increase, even outside the operating range, with large flow, low efficiency, and high energy consumption. On the surface, it seems that pumping speed can be increased. Pumping efficiency is improved, but it is actually not worth the gains. It is not advisable to promote it. When the flow rate of the pump reaches or exceeds the maximum extraction volume of the well, the structure of the filter layer outside the well pipe will be damaged. In light cases, a large amount of sand will enter the well and the wellhead Sinking near the ground will endanger the safety of the well. In addition, the pump in the long-term high head, large flow, low efficiency, high-speed operation, the water flow rate of the pump is accelerated, will destroy the chemical balance of groundwater, so that dissolved substances in the water precipitation, precipitation in the filter inlet gap or gap , Speed ​​up scaling, resulting in plugging of the filter, and as the clogging increases over time, the pump will be subject to corrosion and cavitation.