Design of mechanical seal of high-pressure grey water circulation pump for coal chemical industry:
To make the high-pressure grey water circulation pump stable, long-term and reliable, it is necessary to design high-quality mechanical seals carefully. How to use new materials and new processes to improve the high temperature resistance, high pressure resistance and abrasion resistance of mechanical seals is an important research direction.
The shaft seal of the high-pressure gray water circulating pump belongs to the category of high-pressure mechanical seals. The American API682 mechanical seal standard is no longer applicable, and a unique design method must be adopted. It adopts single-end, built-in, multi-spring, balanced, and cartridge mechanical seals. The main sealing material (moving and static rings are made of high-strength and high wear resistance materials, the spring is made of imported Hastelloy C alloy, and the sealing ring is made of fluorine. Rubber and tetrafluoroethylene type V ring; the design pressure of the mechanical seal is 12-25MPa, and the design temperature is 350℃, which can meet the requirements of working conditions. We have applied for a patent for the design of high-temperature and high-pressure mechanical seals. The patent features are: There are a number of evenly distributed fluid dynamic pressure grooves on the end surface of the moving ring or the static ring. A comet-shaped lubricating wedge with the same number of grooves is formed on the initial surface. It can not only keep leak-free when transporting high temperature and high pressure media for a long time, but also meet the high reliability, high stability and flexible follow-up of the mechanical seal under high pressure. Performance, thereby increasing the service life of the pump.
The mechanical seal cooling method adopts the API PLAN32 flushing and cooling scheme. The mechanical seal cavity is formed by the head and the sealing gland. A high-hard alloy wear-resistant throttle ring is designed at one end of the head, which is matched with the pump shaft and wear-resistant throttle ring The gap between the head and the head should be calculated and designed according to the temperature change curve of the selected material. The entire device should be equipped with an independent high-pressure sealing water system, and the washing water pressure of the mechanical seal should be about 0.2 MPa greater than the outlet pressure of the pump.
Design of Bearing Box Assembly of High Pressure Grey Water Circulating Pump for Coal Chemical Industry
When the high-pressure gray water circulating pump is working, the inlet pressure is very high, and the impeller can bear the axial force and radial force. The bearing box assembly must be specially designed. It is necessary to consider that the thrust bearing can fully withstand the huge axial force, and the bearing box and shaft must With high strength, rigidity and reliability, the front and rear bearings must be able to withstand all axial and radial forces. Since the pump is adjusted at the inlet without pressure, the direction of the pressure difference between the front and rear cover of the impeller points to the suction port of the pump, and when the inlet is pressurized, the direction of the pressure difference between the front and rear cover of the impeller points to the driving side of the pump, so the bearing box The drive side is designed with a double row angular contact ball bearing and a single row angular contact ball bearing installed in the opposite direction of the double row angular contact ball bearing. The radial force of the pump is all designed and installed on the cylindrical roller bearing in front of the bearing box. bear.
The high-pressure gray-water circulating pump has a high working temperature, and the bearing box should be designed with a larger oil tank, and the bearing lubrication should be lubricated by thin oil. In order to cool the bearings and lubricating oil well, the bearing box must also be designed with a larger water cooling cavity, and the cooling water volume must be calculated by the heat shield to reduce the temperature transmitted to the motor to the temperature that the matching motor can withstand.
