Mechanical tightly closed, also known as the end face tightly closed, it has a pair of vertical axis of rotation of the end face, the end of the fluid pressure and the mechanical effect of external elasticity, relying on the right to help close tightly with the other to maintain fit, and Relative sliding, thus avoiding fluid leakage.
First, the common phenomenon of leakage:
The proportion of mechanical seal leakage leakage accounted for 50% of all maintenance frequency pump for more than 100%, closed tightly mechanical operation of a direct impact on the normal operation of the pump, the summary is summarized as follows.
1. Periodic leakage:
(1) axial movement of the pump rotor large amount, to help tightly closed and the shaft of the large amount of interference, moving the ring can not be flexible in the axis of movement. In the pump tumbling rotation, dynamic and static ring wear, the lack of compensation for displacement.
Countermeasures: tightly closed in the assembly machinery, the axial axial movement of the amount should be less than 0.1mm, to help tightly closed and the shaft should be moderate amount of interference in the protection of radial tightly closed at the same time, the dynamic ring assembly after the protection of the shaft On the flexible movement (to move the ring to the spring can be free to spring back).
(2) tightly sealed surface lubricating oil is not sufficient to induce dry friction or nap tightly closed end.
Countermeasures: oil chamber cavity lubricating oil surface height should be added to higher than the dynamic and static ring tight sealing surface.
(3) the rotor periodic oscillation. The end of the stator and the upper and lower cover is not aligned or impeller and the main axis of unfair balance, cavitation or bearing damage (wear), this kind of situation will reduce the number of closed life and leakage.
Countermeasures: can be based on maintenance standards to rectify the above-mentioned problems.
2. Small-scale submersible sewage pump seal leakage-induced shaft phenomenon:
(1) 715kW the following small pump seal loss of the effectiveness of each often sprouting shaft, grinding shaft position are the following: the ring to help tightly closed ring, static ring position, a small amount of spring grinding axis phenomenon.
(2) the main end of the grinding shaft:
① BIA-type double-face mechanical tightly closed, the back pressure is not a good situation in the office, the media particles, impurities can easily enter the tightly closed, so tightly closed ineffective.
(2) The main part of the grinding shaft is the rubber striped tube, and because the upper sealing surface is in bad lubricating condition, the friction torque between the rings is bigger than the transmission torque between the rubber strip tube and the shaft.
③ dynamic and static ring to help tightly closed because of the weak acid in the sewage, weak alkaline corrosion, rubber parts have no flexibility. And some have erosion, missed the proper function, initiation of the phenomenon of grinding axis.
(3) To solve the above problems, the following approach is taken:
① protection under the cover, the oil chamber of the degree of cleaning, lubricating oil on the turbidity of the assembly is strictly prohibited.
② seal oil chamber cavity surface oil line should be higher than ring ring tightly closed ring.
③ not the same as the use of different media structure of the mechanical seal selection. The high-lift pump should be a new default mechanical seal structure, the corrosive medium rubber should be selected with weak acid, weak alkali fluorine rubber. Machine sealed static ring should be added anti-pin.
Second, the pressure due to the initiation of leakage:
(1) high pressure and pressure waves caused by the mechanical seal leakage Because the spring than the pressure and the total pressure preset is too large and tightly sealed cavity pressure of more than 3MPa, will close the end face than the pressure is too large, difficult to form liquid film, Severe closed end wear serious, hair calories increased, resulting in a tight seal surface heat variant.
Countermeasures: the assembly of mechanical seals, the spring compression must be implemented according to regulations, not allowed to have too much or too small phenomenon, high-pressure branches under the mechanical tight closure should be taken to deal with. To make the end force reasonable, try to reduce the variants, can be considered appropriate to use cemented carbide, ceramic and other materials with high compressive strength, and enhance the cooling of lubricating oil treatment methods, the choice of * drive form, Pin and so on.
(2) the vacuum conditions caused by the operation of the mechanical tight seal leakage tower pump in the start-up, shutdown process, because the pump inlet congestion, pumping media, including gas from the end, may make tightly sealed cavity exposed negative pressure, tightly closed If the negative pressure inside the cavity, will lead to tightly closed end of the dry friction, built-in mechanical tight sealing will be the initiation of leakage (water) phenomenon, vacuum tightly closed and positive pressure is not close to close the object is closed tightly directional difference, And mechanical tightly closed also has its suitability in a certain direction.
Countermeasures: that the appropriate use of double-end mechanical tightly closed, so help to improve the conditions of lubricants, increase the tight closure performance.
First, the common phenomenon of leakage:
The proportion of mechanical seal leakage leakage accounted for 50% of all maintenance frequency pump for more than 100%, closed tightly mechanical operation of a direct impact on the normal operation of the pump, the summary is summarized as follows.
1. Periodic leakage:
(1) axial movement of the pump rotor large amount, to help tightly closed and the shaft of the large amount of interference, moving the ring can not be flexible in the axis of movement. In the pump tumbling rotation, dynamic and static ring wear, the lack of compensation for displacement.
Countermeasures: tightly closed in the assembly machinery, the axial axial movement of the amount should be less than 0.1mm, to help tightly closed and the shaft should be moderate amount of interference in the protection of radial tightly closed at the same time, the dynamic ring assembly after the protection of the shaft On the flexible movement (to move the ring to the spring can be free to spring back).
(2) tightly sealed surface lubricating oil is not sufficient to induce dry friction or nap tightly closed end.
Countermeasures: oil chamber cavity lubricating oil surface height should be added to higher than the dynamic and static ring tight sealing surface.
(3) the rotor periodic oscillation. The end of the stator and the upper and lower cover is not aligned or impeller and the main axis of unfair balance, cavitation or bearing damage (wear), this kind of situation will reduce the number of closed life and leakage.
Countermeasures: can be based on maintenance standards to rectify the above-mentioned problems.
2. Small-scale submersible sewage pump seal leakage-induced shaft phenomenon:
(1) 715kW the following small pump seal loss of the effectiveness of each often sprouting shaft, grinding shaft position are the following: the ring to help tightly closed ring, static ring position, a small amount of spring grinding axis phenomenon.
(2) the main end of the grinding shaft:
① BIA-type double-face mechanical tightly closed, the back pressure is not a good situation in the office, the media particles, impurities can easily enter the tightly closed, so tightly closed ineffective.
(2) The main part of the grinding shaft is the rubber striped tube, and because the upper sealing surface is in bad lubricating condition, the friction torque between the rings is bigger than the transmission torque between the rubber strip tube and the shaft.
③ dynamic and static ring to help tightly closed because of the weak acid in the sewage, weak alkaline corrosion, rubber parts have no flexibility. And some have erosion, missed the proper function, initiation of the phenomenon of grinding axis.
(3) To solve the above problems, the following approach is taken:
① protection under the cover, the oil chamber of the degree of cleaning, lubricating oil on the turbidity of the assembly is strictly prohibited.
② seal oil chamber cavity surface oil line should be higher than ring ring tightly closed ring.
③ not the same as the use of different media structure of the mechanical seal selection. The high-lift pump should be a new default mechanical seal structure, the corrosive medium rubber should be selected with weak acid, weak alkali fluorine rubber. Machine sealed static ring should be added anti-pin.
Second, the pressure due to the initiation of leakage:
(1) high pressure and pressure waves caused by the mechanical seal leakage Because the spring than the pressure and the total pressure preset is too large and tightly sealed cavity pressure of more than 3MPa, will close the end face than the pressure is too large, difficult to form liquid film, Severe closed end wear serious, hair calories increased, resulting in a tight seal surface heat variant.
Countermeasures: the assembly of mechanical seals, the spring compression must be implemented according to regulations, not allowed to have too much or too small phenomenon, high-pressure branches under the mechanical tight closure should be taken to deal with. To make the end force reasonable, try to reduce the variants, can be considered appropriate to use cemented carbide, ceramic and other materials with high compressive strength, and enhance the cooling of lubricating oil treatment methods, the choice of * drive form, Pin and so on.
(2) the vacuum conditions caused by the operation of the mechanical tight seal leakage tower pump in the start-up, shutdown process, because the pump inlet congestion, pumping media, including gas from the end, may make tightly sealed cavity exposed negative pressure, tightly closed If the negative pressure inside the cavity, will lead to tightly closed end of the dry friction, built-in mechanical tight sealing will be the initiation of leakage (water) phenomenon, vacuum tightly closed and positive pressure is not close to close the object is closed tightly directional difference, And mechanical tightly closed also has its suitability in a certain direction.
Countermeasures: that the appropriate use of double-end mechanical tightly closed, so help to improve the conditions of lubricants, increase the tight closure performance.
Manufacturers recommend: Shenlong stainless steel submersible pump
Keywords:Stainless steel water supply equipment, stainless steel pumps, maintenance, main
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