D (P), DF (P), Dy (P) and MD (P) series self balancing centrifugal pumps are divided into single suction multistage mechanism and double suction multistage mechanism. They have been successfully developed by our company for many years on the basis of D-type single suction multistage centrifugal pump. This series of pumps is the best substitute for D-type multistage pump.
This series of products have wide efficiency area, good cavitation performance, stable operation, less vulnerable parts, greatly improved reliability, and greatly reduced user maintenance cost, so as to reduce the life cycle cost of the pump. It can be used to transport clean water without solid particles (Abrasives), suspended solids or other liquids with physical and chemical properties similar to clean water. It can also be used to transport hot water, oil, corrosive or abrasive media by changing the material of the pump (or the material of the flow-through parts of the pump), sealing form and adding a cooling system. The allowable inlet pressure of the pump shall not be greater than 0.6MPa.
D (P), DF (P), Dy (P) and MD (P) series self balancing multistage centrifugal pumps are mainly divided into the following types according to their trial range:
Type D (P): it is used to transport clean water without solid particles and with temperature lower than 80 ℃ or liquid with physical and chemical properties similar to clean water. It is suitable for mines, factories and urban water supply and drainage projects.
DF (P): used to transport corrosive liquids without solid particles at - 20 ~ 105 ℃. The user can select the name of the conveying medium according to the. Concentration, specific gravity, service temperature and pump inlet pressure, reasonably select the material of the pump, sealing form, pump structure and determine the power of the motor.
Dy (P) type: used to transport oil and petroleum products without solid particles, with a temperature of - 20 ~ 105 ℃ and a viscosity of less than 120 centigrade.
MD (P) type: it is used to transport neutral mine water and other similar sewage with particle content ≤ 1.5%, particle ≤ 1.3mm and temperature of - 20 ~ 80 ℃.
Product performance:
Performance range D (P), DF (P), Dy (P) and MD (P) pumps with the same performance parameters Discharge diameter 40 ~ 300mm, flow Q = 3.75 ~ 945m3 / h, lift H = 108 ~ 1383m, motor power n = 18.5 ~ 34150kw (Note: the performance parameter value is the state value of clean water at room temperature), executive standard GB / t5657-95 technical conditions of centrifugal pumps (Class III), JB / t1051-93 types and basic parameters of multistage clean water centrifugal pumps, GB / t3216-2005 hydraulic performance acceptance test of rotary power pumps, levels 1 and 2, mt114-2005 Multistage centrifugal pump for coal mine
Technical characteristics:
New structure: the impeller and rotor components are symmetrically arranged. The axial forces generated by symmetrical impellers at all levels offset each other. The automatic balance of huge axial thrust in the pump cavity can be realized without using the balance disc structure;
New technology: unique throttling and decompression device, odd stage balance device;
High efficiency: the flow channels of impeller and guide vane are well aligned to the neutral, and the efficiency will not decrease significantly with the wear of balance disc and the forward movement of rotor parts; Without the leakage of balance water, the volume loss is reduced and the efficiency of the pump is improved, which is 1% ~ 2% higher than that of ordinary D-type pump on average;
Good cavitation performance: it has good cavitation performance. The first stage impeller of some types of pumps adopts double suction structure;
Strong reliability of mechanical seal: when the pump is started and stopped, the rotor parts do not move axially, and there is no axial pulsation during operation, which overcomes the problem of poor reliability of mechanical seal that has been perplexing multi-stage pump;
Wide application: the small clearance balance disc is cancelled, which is more suitable for occasions with worse medium properties than ordinary D-type pump;
The maintenance cost is reduced and the reliability is improved;
The peak value of axial force is low: the axial force is only half of that of ordinary D-type pump, which greatly reduces the interference effect on the pump and greatly improves the rigidity;
Low maintenance cost: it adopts precision casting and unique throttling and pressure reducing device to play an auxiliary supporting role, greatly reducing the vibration and noise of the pump and long service life;
The pump has uniform thermal expansion (cold contraction) and good symmetry: the pump has uniform thermal expansion (cold contraction) up and down, left and right, and good symmetry
Structure description:
D (P), DF (P), Dy (P) and MD (P) pumps are horizontal balanced centrifugal pumps. According to the suction form, they are divided into single suction multistage structure and double suction multistage structure (except that the first stage of 280-95, 360-95 and 450-95 pumps is double suction structure, other pump types are single-stage structure). The suction inlet is horizontal on the water inlet section, and the outlet is vertical on the water outlet section. Tighten the water inlet section The middle section, outlet section and secondary inlet section are integrated, and the lift can increase or decrease the number of stages of the pump (the suction port can be vertical according to the user's needs).
1. Main parts of water pump: inlet section, middle section, outlet section, secondary inlet section, positive guide vane, reverse guide vane, positive impeller, reverse impeller, shaft, throttling and pressure reducing device, gear sleeve, bearing body, transition pipe, etc;
2. The rotor is composed of positive impeller, throttling and pressure reducing device, reverse impeller, shaft sleeve, bearing gear sleeve and other parts installed on the shaft; The bearing adopts "solid traveling" dry oil lubrication structure, the driving end adopts cylindrical roller bearing, and the end adopts angular contact ball bearing; 3. The working chamber of the pump is composed of inlet section, middle section, outlet section, secondary inlet section, positive guide vane, reverse guide vane, transition pipe, etc;
4. The sealing surfaces between the water inlet section, middle section and water outlet section of the pump are sealed with sealant or "O" ring, and a sealing ring is installed between the rotor part and the fixed part. The guide vane sleeve shall be sealed. When the wear degree of the seal ring and guide vane sleeve has affected the working performance of the pump, it shall be replaced in time;
5. There are two types of shaft seals: mechanical seal box and packing seal. When the pump adopts packing seal, the position of packing ring shall be placed correctly, and the tightness of packing must be appropriate, so that the liquid can seep out drop by drop. Various sealing elements of the pump are installed in the sealing cavity, and water with a certain pressure shall be introduced into the cavity to play the role of water seal, water cooling or water lubrication. A replaceable shaft sleeve is installed at the shaft seal to protect the pump shaft;
6. This series of pumps are directly driven by prime mover through elastic coupling. Viewed from the prime mover, the pump rotates clockwise. (the conventional configuration of the motor is Y series motor, and Yb / YB2 series explosion-proof motor is used in the case of combustible gas.) Working principle: the impeller rotated by the pump shaft driven by the motor works on the liquid to increase its energy, so that the required amount of liquid is absorbed by the suction tank
