subject: Towards The Universal Mechanical Seal For Industrial Pumps [print this page] Even though several efforts have been made to improve mechanical seal throughout the last 50 years, the main problems with industrial pumps remain leaking seals.
The article entitled 'Towards the universal mechanical seal for industrial pumps' deals with the development and test of a cartridge-type mechanical seal combining the ability of running dry with abrasive resistance. The design of seal test is made on the basis of the most common failures in mechanical seals in pumps.
The new seal design consists of a cartridge seal in which one of the seal rings has a partitioned face made of two different materials. When the temperature rises by dry running the soft part of the seal face expands so only materials with low friction are in contact. When running in an abrasive environment the soft part wears, leaving the hard part with the sealing function. The selection of design and materials is based on the test of more than 500 seals with a total of around 2,000,000 hours.
The positive properties are confirmed by numerous tests, but the new seal is still not suited for hot water.
Mechanical seal is not packing seals. It is secured to the shaft by the ring and fixed to the pump casing on the stationary ring and the two tight end close (by the spring force sliding push) to seal. In the mechanical seals, the leak back to the water by the ring seat cover on the high Lupi Fu (Golubiev) reverse spiral groove to enhance the pressure, through channels and static forced into the ring to ring in the gap, to take away heat and friction Bubble wash away impurities. Withstand the high pressure seal water pressure while the water escape, the other coming into static and dynamic link between maintaining a layer of mobile membrane, so that movement does not touch the torus. Thin film flow, due to the role of high-pressure water, so very little escape of water.
Mechanical seals the poor quality of welding pipe system to pump serious impact on the safety of the sea 200MW electricity to pump mechanical seals design is 80 liquid temperature alarm, 90 jump pump. When running a small leak in the pipe line to seal fluid temperature increases slowly (because of fluid through heat exchangers to reduce the mechanical seals, mechanical seals or liquid cooling may not be good); when piping a serious leak to seal liquid temperature rapidly increased. These are so mechanical seals ring and static ring and the front and side are not very good cooling, overheating and damage to static ring. Often occurred on leakage due to mechanical seals piping leading to the pump trip, but also increased the wear of mechanical seals. Therefore, the mechanical seals welding quality control department has put forward higher requirements.
Water quality impact on the mechanical seals. As the mechanical seals on the water quality are higher, and when the water quality deterioration, due to cyclic mechanical seals piping quite thin, so that rapid mechanical seals easy to plug the resulting fluid temperature; when a pump running at low speed When the water quality deterioration, due to high Lupi Fu (Golubiev) reverse spiral grooves to enhance the lower pressure, so that impurities can not be taken away by the water in a timely manner, resulting in impurities deposited on the mechanical seals paste and surface Department, scratch mechanical seals ring movement The front and side, so that mechanical seals leakage. Hence the need to strengthen Kai down and running unit water quality monitoring.
In hot water it is a well-known problem that the hard seal faces cause vibrations and noise. The new cartridge mechanical seal is a step forward towards the universal mechanical seal for industrial pumps, but it will still be long before the vision of maintenance free pumps is fulfilled.
