According to the survey, more than 86% of the pumps in petrochemical process units use mechanical seals. With the development of mechanical seal technology, the mechanical seal will occupy a more important position in the pump. So, what is the role and significance of mechanical seals?
The role of mechanical seal:
Improve machine efficiency and reduce energy consumption:
1. Reduce the internal leakage, external leakage, and leakage of the machine, and improve the volume efficiency of the machine. For example, the Daqing Oil Refinery changed the impeller ring of the coking 5FDJ5×2 centrifugal pump to a mechanical seal, increasing the pump efficiency by 3.6% to 5.6%.
2. Reduce friction loss and improve the mechanical efficiency of the machine. For example, changing the double-face seal to a single-face seal, the unbalanced type to the balanced type, and the double-supported bottom-reducing pump closing one end (the so-called head-cutting pump) to reduce the seal can reduce friction loss and improve mechanical efficiency.
3. Change the sealing method to improve the efficiency of the machine or unit. For example, the canned pump is changed to a mechanical seal pump to improve the efficiency of the motor; the magnetic drive pump is used to improve the efficiency of the machine.
4. Change the auxiliary system to reduce energy consumption and improve unit efficiency. For example, the self-flushing of the hot oil pump is changed to the circulating flushing of the small impeller; the double-end seal is changed to a single-end seal, which saves the energy consumption of the oil sealing auxiliary system.
Saving raw materials:
For example, process fluid recovery, reduction or elimination of power steam and process fluid losses, reduction of seal oil losses, etc.
Improve machine reliability:
For example, the leakage and life of the shaft seal determine the reliability of the shaft seal and the machine.
Safety and Environmental Protection:
According to the investigation report of a factory in Japan, 32 of the 786 accidents that occurred were caused by leakage (accounting for 42%). In addition, the leakage of process fluid will also cause environmental pollution, including air pollution, water pollution, and workshop environmental pollution.
The meaning of mechanical seal:
1. Although sealing technology is not a leading technology, it is a decisive technology. For example, the space shuttle Challenger of the United States fell due to a sealing accident; for the sake of safety and reliability, the circulating pump of the nuclear power plant was changed from a pump with a shaft seal to a pump without a shaft seal. After improving the mechanical seal, because of its reliable operation, the pump without shaft seal was changed back to a pump with shaft seal, thereby improving the efficiency of the motor. These two things fully demonstrate that although the mechanical seal is not a leading technology, it is a decisive technology.
2. Although the seal is not big, it is only a component, but it can determine the safety, reliability, and durability of the machinery and equipment. The shaft seal in the pump kettle of the petrochemical plant is not large. Affecting the work of pump equipment, combustion or explosion will also occur, resulting in the shutdown of process equipment and personal casualties.
3. Mechanical seals account for about 50% of the workload in the daily maintenance of equipment such as pumps, kettles, etc. Through the investigation of several petrochemical enterprises at home and abroad, it is explained that in the daily maintenance of equipment such as pumps and kettles, the maintenance work of mechanical seals The amount is almost 50%. About 70% of centrifugal pump maintenance costs are due to seal failure.
The above is the function and significance of the mechanical seal, I hope it will be of great help. If you want to know more about mechanical seals, please continue to pay attention to the official website. We will update relevant articles and products from time to time, provide relevant product information and materials, and look forward to your visit and consultation.