Pump as a rotating machinery, the shaft and the pump casing must leave a gap between, in order to prevent the liquid from the pump or air leakage into the pump (the entrance for the vacuum situation), the shaft and the pump casing is generally provided with a shaft seal . In recent years due to the continuous development of high temperature and high pressure pump, the sealing problem has become one of the important factors affecting the safety of pump. Currently used shaft seal devices generally have the following forms: packing seal, mechanical seal, labyrinth seal, floating ring seal, and for many low-pressure thermal power plant water pump, the use of soft packing seal. Use asbestos, carbon fiber, PTFE resin and other materials woven into a square or round. Soft packing seal with wide use, cheap and so on. With soft-filled pump usually leaks, the general use of tight disk gland method. If it is invalid, you must stop the pump to change the stuffing again. The soft filler generally short life cycle, and the larger wear on the sleeve, which makes peacetime maintenance increases, and not economical. At this stage can use other methods to replace the use of packing it? Draw lessons from foreign experience and combined with the actuality of China's thermal power plant, packing filler injection method can be used instead of packing. Filler gun The principle of injecting a soft packing is to inject the soft clay filler into the packing chamber of the pump with a higher pressure to replace the rope packing. The other parts of the stuffing box remain unchanged. 1 transformation steps As the low-pressure thermal power plant at this stage the use of multi-purpose packing seal, which is facing a how to transform the original basis, based on experience, are summarized as follows. 1.1 clean packing room Thoroughly clean up the original packing room of the pump before the transformation, and do not allow any impurities and dirt. If the water ring, can not be abandoned. This work must be uncovered, in order to save time and materials, it is best to carry out the pump overhaul. This will allow overhauls and remodeling synchronization. 1.2 pump cover drilling In order to inject the packing, an injection hole fitting must be installed on the cap. The connector must be specially machined. The thread should be matched with the stuffing gun connector, and the connector gland should be machined. For the water pump with water seal, the water sealing tube can be removed and drilled and tapped directly on the water seal. 1.3 plus packing root In order to prevent the packing leakage and internal leakage, before and after filling the chamber at both ends of each installation of a circle of packing, you can add carbon fiber packing or PTFE packing. Because it is uncovered after the addition of packing roots, so add packing must pay attention to the gap with the root should be close. 1.4 plus filler Press the packing into the packing chamber first by hand, without too tight. Then close the pump cover, bring together the packing gland, then fill the filler gun can be injected into the pressure. At this point the packing should be tight. 2 Precautions According to Neijiang white horse power plant on the pump of such transformation and maintenance experience, should pay attention to the following items. 2.1 modification can only be carried out in the positive pressure pump As in the negative pressure pump (such as jet pump) on the transformation, packing easily sucked into the pump, at this stage the White Horse Power Plant has been modified steam turbine plant industrial pumps, water pumps, circulating pumps, water pumps and boiler plant some of the low-pressure pump, run Good effect. 2.2 packing gland not too tight After the packing packing tight packing gland not too tight, there should be some loose. This filler injection gun filler, according to gland tightness to determine whether the filler is full. Gland by the loose tight, it means that the filler has been filled. When testing the pump, replenish the filler according to the leak condition. With the start of the pump, the filler injected only due to rotational friction, it will squeeze out part of the pump, and produce a certain gap, resulting in leakage. Immediately fill the filler until no leaks. Injection filling should be divided into several times, the action should be slow, each interval of about 5min. If the packing is too tight and smoke, you can loose the packing gland, while filling the room to pour cold water cooling. After the pump is turned for a period of time, the packing and sleeve have been running in well so that they will not smoke anymore. 2.4 on the pump cover injection hole connector requirements The injection hole on the pump cover joints should be close together, available tape wound, gland should have a soft washer. After the injection pressure with the filler joints, and then close the gland. 2.5 injection can not be too hard Filler gun pressure is high (up to 10MPa), so the injection can not be too strong, that the gun handle can have a certain pressure. 3 advantages Through the transformation of the pump before and after the operation of the comparison, this transformation has the following advantages. 3.1 save money Although the investment before the reform more (Note: the purchase of the United States to make the filler gun to be 10000.00 yuan /; soft filler 6000.00 yuan / kg), but because of its durability, but also a one-time investment, from a longer period See, than using packing can save about 30% of funds. 3.2 small amount of maintenance and convenience When the pump runs less time that is a leak, the gun can be directly injected into the stuffing chamber filler, and without downtime, the method than the tight packing to facilitate and effective. And such a filler to use a longer period, usually up to three months or more (continuous operation of the pump). Do not need to change the filler during operation just fill filler. 3.3 sealing effect The use of good effect, high safety, wide range of use. Due to the filler was mud, under pressure in the case of close together, so the sealing effect is good. The filler is mainly made of carbon fiber, Teflon, Kevlar and other synthetic raw materials, high wear resistance, small friction coefficient, but also has good impermeability, the protection of the sleeve is very favorable. By comparison, the use of bushings longer than double the length of the transformation. And it is not only for cold water pump, but also for hot water pump (such as hydrophobic pump), and for different sizes of pumps. At this stage, most single-stage cantilever centrifugal pumps in Guang'an Power Plant are mechanical seals that can be retrofitted to low-pressure pumps such as double-suction single-stage centrifugal pumps, such as open cycle cooling water pumps, while reducing maintenance and Operators and equipment leakage point, and promote the improvement of the whole plant economic benefits. Thermal spray wires are used in thermal spraying processes, which involve the application of a coating material onto a surface. These wires are specifically designed to be melted and sprayed onto a substrate to create a protective or functional coating. Spray Wires,Arc Spray Coating,Thermal Arc Spray,Thermal Spray Wire Luoyang Golden Egret Geotools Co., Ltd , https://www.xtcthermalspray.com
2.3 filler added
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