In urban construction, excavation of the foundation, buried underground pipelines, the underground water is the first problem to be solved, and solve the problem is the key to the pump can be very smooth water and sludge from the ground, the general water diving The pump can not complete the project because the water under the subgrade has a lot of sediment that will trap the impeller of the pump and cause the pump motor to burn out so it must use a sewer submersible pump to complete the pumping The task. Currently on the market of sewage sludge submersible pump in use does bring a lot of convenience to the construction unit, but it also has some drawbacks, that is, its service life is not very long, because the sludge is different Specifications of the trash and stones, the formation of the pump body outlet blockage or entanglement of the impeller so that the motor does not turn, the above situation soon pump can not be used again. To solve this problem, it is necessary to discharge the sundries and long fibers drawn by the water pump and then discharge the dirty water together with the water so as to not only prolong the service life of the water pump but also create conditions for accelerating the construction speed of municipal engineering . There is also a mixing pump, its role and cutting slightly different. It is equipped with a stirring mechanism attachment, when pumping to the bottom, due to underwater sediment or sediment to reach a certain concentration and uneven proportion, so that the water is not drained by the thick sand sucked into the card, which first They need to be stirred into a uniform and diluted into thin sand, so do not damage the pump is easy to play out. In addition, in order to maintain the balance of the axial force of the main impeller, an auxiliary impeller structure is to be provided, which can reduce the pressure in the sealed chamber and greatly increase the axial force of the electric pump and the mechanical seal. For the pump cooling problem has always been the key issue of pump life, if the cooling effect is not good, the motor temperature will rise, so that the motor power continues to rise, the motor is easy to burn, shorten the life of the pump. In order to solve this problem, we use the external circulation cooling system to enhance the cooling function, which can ensure that when the pump exposed water, but also work properly. For the delivery of more corrosive liquid, you can first use a stainless electric pump, its corrosion resistance, and reliability will be greatly improved.