Technical breakthrough advantage of double imported self-balancing multi-stage pump
The existing multi-stage pumps on the market mainly include D-type and DG-type multi-stage pumps with impellers arranged in order from left to right or right to left, and DP-type self-balancing multi-stage pumps with symmetrical arrangement of impellers and self-balancing axial force. Structure, these two types of pumps are multi-stage centrifugal pumps composed of single-suction impellers or first-stage double-suction impellers and the remaining single-suction impellers, and there are also multi-stage centrifugal pumps composed of double-suction impellers. For multi-stage centrifugal pumps composed of full double-suction impellers, due to the use of double-suction impellers, a large number of impeller stages will cause the inter-stage flow path of the impeller to be very complicated and difficult to realize. Generally, multi-stage pumps composed of double-suction impellers only have 2 to 3 stages. . For the D-type and DG-type multi-stage centrifugal pumps with impellers arranged in sequence, the conveying medium is from one end of the inlet to the other end; the impeller is symmetrically arranged with the axial force self-balancing ZD self-balancing multi-stage centrifugal pump, and the conveying medium is from one end The inlet enters, and when it is close to the middle position, it is connected to the other end through the guide tube and then discharged from the middle outlet; although the inter-stage flow path of the multi-stage centrifugal pump composed of double suction impeller is very complicated, there is only one inlet and one outlet for delivery. medium.
In order to ensure the effectiveness of the high-pressure end seal of the multi-stage centrifugal pump with the above structure, it is often necessary to install a balanced water pipe to reduce the pressure at the shaft seal at the high-pressure end of the pump. A multi-stage centrifugal pump composed of a pump with a symmetrical impeller arrangement and a double-suction impeller also requires sealing devices at the high and low pressure zones of the pump to prevent a large amount of medium leakage. The arrangement of the balance water pipe and the sealing device inevitably increases the volume loss of the pump and reduces the efficiency of the pump.
Aiming at the above-mentioned shortcomings of the existing technology, the technicians of Zoomlion Pump Industry have developed a new type of self-balancing multi-stage pump, which is to provide a multi-stage pump that can completely avoid the above two volume losses and is composed of double suction impellers. The centrifugal pump is a simpler double-import self-balancing multi-stage pump with a new structure.
The dual-inlet self-balancing multi-stage pump includes a medium inlet and an outlet. Between the inlet and the outlet is a multi-stage impeller formed by superimposing several impellers. It is characterized in that the outlet is in the middle of the pump, and the impeller corresponding to the outlet is a double-suction impeller. , The inlet consists of two multi-stage impellers located at the two ends of the pump, and the multi-stage impellers between the inlet and the outlet at both ends are arranged symmetrically along the double-suction impeller corresponding to the outlet. Several single impellers forming the multi-stage impeller are all single suction impellers.
The double-inlet self-balancing multi-stage pump includes a segmental double-inlet self-balancing multi-stage centrifugal pump with a guide vane at both ends and a volute in the middle outlet shell, and a double-inlet self-balancing multi-stage pump with a volute structure. Grade centrifugal pump. Since both ends of the pump are the inlets of the pump, the conveying medium has not been pressurized by the impeller, and there is no need to have a balanced water pipe without a high-pressure end; at the same time, because the single-stage impellers at both ends are arranged symmetrically, the double-suction impeller is arranged at the pump outlet. The axial force generated by the impeller of the pump is automatically balanced, and the pressure at both ends of the double-suction impeller is basically the same, so there is no need to set a sealing device in the high and low pressure area, which reduces the leakage of the pump, thereby avoiding the existing multi-stage centrifugal pump setting balance The volume loss caused by water pipes and sealing devices improves efficiency. Moreover, the structure of the utility model is simpler than that of a multi-stage centrifugal pump composed of double suction impellers.
