ANALYSIS OF LEAKAGE AND MAINTENANCE OF PUMP MECHANICAL SEAL

Chemical pump is one of the core components for chemical industry production. The stability and precision of its operation will directly affect the production efficiency of the chemical industry and have a huge impact on the production efficiency of chemical companies. At the same time, in the actual application process of chemical pumps, the chemical process conditions faced by the production of chemical pump machinery are complex. If it is not possible to complete the inspection and maintenance design of chemical pump machinery, it is very likely Reduce the operating efficiency of chemical pump machinery, and bring about some problems of chemical pump machinery, giving a series of troubles to the chemical industry production process.

Overview of maintenance problems for chemical pumps

First of all, there are problems with the sensor part of chemical pump machinery used in the production process of the chemical industry. If there is a problem with the corresponding sensor part, it will be difficult to quickly obtain the corresponding data information on the DCS system, which will cause it to be difficult for the chemical pump machinery to keep running, and its production efficiency will be difficult to be guaranteed. Secondly, under the chemical process reaction conditions of chemical pump machinery, sudden abnormal vibration conditions of chemical pump machinery and abnormal sound of equipment inside chemical pump machinery are related to abnormal production conditions of chemical pump machinery. In order to effectively solve these problems, the technical staff of the chemical workshop need to carefully summarize the reasons for these problems and come up with effective solutions. Third, in the chemical industry production process, in order to ensure the continuity and stability of the feed, the pump machinery for chemical industry often adopts the method of intelligently controlling the opening degree, which results in higher requirements for the field's sensing degree. If errors occur, it can easily lead to production problems. Fourth, due to the long production time of chemical pump machinery, the production conditions experienced are severe and complicated. This requires the corresponding inspections to be strengthened during the maintenance process to ensure that the problems existing in chemical pump machinery are discovered at the first time.

Overview of leaks in mechanical seals for chemical pumps

 First, the problem of cracking of mechanical seals of pump machinery is for chemical industry. If the stress of the chemical pump machinery is not uniform, it will easily cause the external crack of the mechanical machinery of the chemical pump machinery, and then cause the leakage of the material liquid. In view of this situation, it is necessary to start from the stress analysis of chemical pump machinery. The core of the maintenance management of this part is to perform the stress analysis of the corresponding chemical pump. At the same time, as the application time of chemical pump machinery changes, the probability of chemical pump machinery failure will also change accordingly, which determines that in the process of using chemical pump machinery, Analysis of position and force. Second, analyze the external corrosion of chemical pump machinery. In the process of chemical industry production, chemical pump machinery passes through a complex chemical reaction environment. If the leakage of chemical pump mechanical seal is not the corresponding special anti-corrosion equipment material, it will easily lead to the leakage problem of chemical pump mechanical seal, which is also the core level to pay attention to in the research of chemical pump mechanical seal leakage.

Leak cause analysis

Seal leakage caused by mechanical wear.

Mechanical wear will cause the normal mating relationship of the seal pair to be destroyed. When there is a certain amount of wear on the end surface, the seal must make axial displacement and radial swing every time the drive shaft rotates. Therefore, in each rotation, the sealing sub-end surface tends to produce slight separation and leakage. From the wear marks, movement and wear can be judged, and the cause of seal leakage can be determined. For example, the wear marks on the seal pair are uniform, and the parts fit well, which means that the coaxiality of the transmission part is good. The leakage at the seal end face may not be caused by the seal itself. If the leakage is constant, it means that the leakage does not occur between the two end faces, but may occur in other parts, such as the static seal. For another example, the seal leaks when it is used, and no signs of wear on the friction end surface are observed. The rotation ring may not rotate or slip relative to the stationary ring. The reason may be that the anti-rotation pin is loose or broken, or the diameter of the base is smaller than The outer diameter of the seal is caused by the incomplete installation.

Seal leakage caused by thermal damage

It is mainly caused by the overheating of the seal during use. Overheating not only causes the seal pair to deform and wear, but also may cause thermal cracking and blistering. Generally, radial cracks appear on the surface of the seal ring under the effect of excessive thermal stress, which is called thermal cracking. Under a short time mechanical load or thermal load, thermal cracking will occur. For example, due to dry friction, interruption of the cooling system and other thermal cracks, the seal ring wear will increase and the leakage will increase rapidly. For balanced seals, even the seal rings are separated. In order to avoid thermal cracking, it is necessary to grasp the mechanical-physical properties of the material, consider the possible thermal cracking in the design, and specify the operating conditions.

Seal leakage due to corrosion

The corrosion of mechanical seals is divided into chemical corrosion and electrochemical corrosion. Corrosion is one of the most important reasons for mechanical seals to leak and cause mechanical seal failure. Because the seal is in contact with corrosive media, surface corrosion will occur, and even severe corrosion points will be formed on the surface to form pitting corrosion. Intergranular corrosion generated on the grain boundaries of the metal will penetrate into the interior of the metal and cause further damage to cause fracture.

Leakage of seal caused by failure of seal parts

For mechanical seals, synthetic rubber 0-rings are often used. The failure of mechanical seal parts is mostly the failure of the auxiliary seal ring. One of the main reasons that the mechanical seal cannot work normally due to leakage is also caused by the failure of the 0-ring. 0-ring failure manifests itself as aging, permanent deformation, swelling deformation, distortion and extrusion damage.

Maintenance strategy for leaks

In the process of solving the leakage and maintenance problems of chemical pump mechanical seals, an in-depth analysis should be performed according to the sensor state, force analysis, and chemical reaction process conditions of chemical pump machinery. At the same time, as a pump machinery for wear and tear, some small use problems are inevitable. Under this background, it is necessary to carry out research work on chemical pump mechanical seal leakage and maintenance problem resolution strategies in combination with the actual situation of chemical pump machinery:

First, in the process of solving the leakage and maintenance of mechanical seals for chemical pumps, for the sensors and DCS control system parts introduced above, it is required to fully consider the chemical pumps during the maintenance of chemical pump machinery. The operating state parameters of the machinery, and the corresponding technical personnel are dispatched to conduct inspections in a timely and effective manner to eliminate possible leaks in the mechanical seals of chemical pumps. At the same time, in the process of chemical pump machinery problems, it is often accompanied by a decline in feed efficiency, pump body pressure drop, chemical pump vibration and so on. In view of this situation, in the process of solving the leakage and maintenance of mechanical seals for chemical pumps, specific problems can be analyzed.

Second, the actual conditions of chemical industry production can be used to solve the leakage problem of chemical pump mechanical seals. In this process, before the start of the project, you can investigate the process parameters of the chemical reaction conditions, and summarize and summarize the possible corrosive liquids, so as to effectively ensure that the selected chemical pump materials can meet the requirements of the chemical process conditions. To prevent corrosion problems, high temperature and high pressure damage to chemical pump machinery, ensure the stable operation of the chemical industry production process.