Because the slurry pump belongs to the most widespread universal mechanical equipment, it has been applied in various industries. Because the working conditions of these industries are not the same, the equipment failures under different application conditions are different, but most of the faults are directly related to the initial selection of equipment and the harsh working conditions after use. The most common faults in alumina production are poor discharge and severe vibration. How to choose horizontal centrifugal slurry pump, and other slurry sewage pumps such as gravel dredge pump and vertical slurry pump, in a correct way, here are some advices.
Slurry pump operation does not discharge or discharge is almost all the application of slurry pump industry has encountered the fault, the first debugging or overhaul after the industrial sludge pump operation does not discharge, which is related to the selection of slurry pump or replacement of spare parts, mostly because the slurry pump feed level is too low or the pump after the operation of the steering error caused.
Slag slurry pump in the normal working state suddenly occurred under the failure of the material mainly has the following aspects:
(1) Blade passage or pump inlet/outlet blockage slag slurry pump under normal working condition suddenly occurs no discharging fault, a large part of the reason is due to the impeller blade passage or pump inlet/outlet pipeline blockage caused by. Because of the slurry pump mud contains many solid particles, some of these solid particle diameter is larger, and slurry generally exist strong coagulability easy to scar, and mixed with other flexible foreign body, will affect the normal pulp into pump cavity, the impeller or import and export pipeline blockage, also make the transfer of energy of pulp is difficult to obtain the impeller. After this fault occurs, the pump cavity will be accompanied by some abnormal noises, and the motor current will also appear a significant downward trend.
(2) the occurrence of cavitation cavitation and impeller of slurry pump or pump imported jams have a connection, due to the impeller and the plugging of imported itself can affect the discharge of slurry pump, and the occurrence of cavitation is not only lead to the pump discharge impeded further, also can produce serious noise and vibration, severe decline in the overall performance of slag pulp pumps, to disrupt the discharge of the pump, The motor current will appear obvious jump.
(3) Severe wear of flow parts the wear of the main flow parts of the slurry pump has a certain gradual process, and with the gradual wear of these flow parts, the performance of the pump will gradually decline. Due to the wear of the over-flow parts, the discharge fault has a long cycle, and the discharge is not smooth, most of the slurry pump will run too smoothly, and the motor current is in a very low but stable state.
Vibration is an inevitable phenomenon during the operation of equipment. According to the severity of vibration degree, it can be divided into different levels. Vibration of equipment within the range of the level is a normal phenomenon.
There are many reasons for the serious vibration of the slurry pump, which can generally be in the following aspects:
(1) the partial load of the slurry pump impeller impeller in the factory through the dynamic balance of alignment processing, quality of each part is relatively uniform, but over the long run will produce certain wear or adhesion after scar, this to a certain extent, led to the partial load of the slurry pump rotating parts, slurry pump running after partial load result in serious unbalanced rotary force caused by the slurry pump vibration.
(2) the retaining bolt looseness slurry pump, relying on multiple anchor bolt connected with the base, between the parts also rely on the bolt to keep the stable state of the pump, as a result of the existence of equipment vibration, slurry pump after a long run will gradually cause the fastening bolt looseness, which can result in slurry pump the bondage of the retaining bolt that has been lost and make the oscillations, At the same time, the vibration of equipment and the further loosening of bolts and wear of components form a vicious cycle.
(3) The good lubrication of the equipment with insufficient bearing lubrication or substandard lubricating oil brand can not only reduce the wear of the components, but also the oil film formed by the lubricating oil between the two parts can absorb a large part of the vibration. When the slurry pump rotates at high speed, the lubricating oil will form sufficient oil film between the rolling bodies of the bearings to reduce the vibration value. If the lubrication of the slurry pump is insufficient or the grade of the lubricating oil is not up to standard, the viscosity is insufficient, it is difficult to form an effective lubricant film between bearings, or the lubricant film is broken prematurely, it will lead to serious vibration of the slurry pumps, and make the bearing produce serious wear.
Shaft seal leakage is the most common fault of slag slurry, especially in the petrochemical industry, more than 80% of pump failure comes from shaft seal leakage, so the treatment of shaft seal leakage will determine the utilization rate and maintenance cost of the pump. And in the shaft seal leakage fault and more than 65% of the fault is caused by compression spring and cooling water scaling caused by the seal end seal poor seal, so the key to prevent the shaft seal leakage is to soften the cooling water of the shaft seal, reduce the speed of cooling water scaling.