DG type multi-stage boiler feed pump

1. Use

1.1 D and DC pumps are multi -stage centrifugal pumps. It is suitable for transportation of water (including miscellaneous mass of less than 1%. The particle size is less than 0.1 mm) and other liquids similar to water in water.

The temperature of the D -type transport medium is not greater than 80 ° C. It is suitable for mining water drainage and factories, urban water supply and other occasions.

The temperature of the DG pump conveying medium is not greater than 105 ° C. It is suitable for small boilers to pump pump pumps or transport similar hot water. 1.2 The performance range of this series (according to regulations):…

flow: 6.3 ~ 450m³/h

lift: 50 ~ 650M

2. Structure Description

This type of pump is mainly composed of shell part, rotor part, balance mechanism, bearing part and sealing parts.

1. Shell part

The shell part is mainly composed of suction section, middle section, discharge section, guide vane, bearing body, etc. connected by bolts. The direction of rotation of the pump, when viewed from the drive end, the pump rotates clockwise.

2. Rotor part

The rotor part is mainly composed of the shaft and the impeller mounted on the shaft, the shaft sleeve, the balance disc and other parts. The parts on the shaft are fastened with flat keys and sleeve nuts to make it integrated with the shaft, and the entire rotor is supported in the pump casing by bearings at both ends. The number of impellers in the rotor assembly is based on the number of pump stages.

When this type of pump is in use, the shaft seal must receive water to seal the water. There are two types of water seals: one is to use the outlet water of the first stage impeller, and the other is to use external water. All the seal water marked in Table 2 refer to external water seal water, and the water seal water of the first stage impeller is used as the water seal water for those not marked with water seal water. The tightness of the packing of the shaft seal must be appropriate, and it is advisable when the liquid can seep out drop by drop. When the temperature of the conveyed medium is higher than 80°C, liquid cooling water must be passed to the water-cooled packing gland and the shaft seal cooling chamber. 3 kg/cubic centimeter, the pressure of the water seal water is 0.5-1 kg/cubic centimeter higher than that of the sealing cavity. The position of the pipeline interface of the water seal and the cooling chamber of the shaft seal of various pumps is different. The position of the pipeline interface along the axial direction is shown in the pump structure diagram.

3. Balance mechanism

The balance mechanism is composed of a balance ring, a balance sleeve, a balance disc and a balance pipeline, etc.

4. Bearing part

The bearing part is mainly composed of a bearing body and a bearing. This type of pump bearings has two types: sliding bearings and flow bearings. None of the bearings bear axial force. When the pump is running, the rotor part should be able to freely move axially in the pump casing. Radial ball bearings cannot be used. The bearings used by various types of pumps are shown in Table 1.

5. Pump sealing and cooling

The joint surface of the suction section, middle section, discharge section and guide vane in the shell part is coated with molybdenum disulfide grease for sealing.

The rotor part and the fixed part are sealed by sealing rings, guide vane sleeves, fillers, etc. When the degree of wear of the seal ring and guide vane sleeve has affected the work and performance of the pump, it should be replaced in time. When this model is in use, the position of the packing ring must be placed correctly. See Table 2 for the distribution of packing and packing rings of various types of pumps.