Dredge pump are under maintenance in regular inspection, therefore, how to maintain the dredge pump is a knowledge and a training programme Do pump would like to share with dredge pump users, in order to ensure dredge pump operate smoothly and safely.
1.Noise, vibration, inspection method: sound, touch, visual check, criteria: no noise, no abnormal vibration.
2.Temperature, inspection method: touch. Criteria: no abnormal high temperature.
3. Content: lubrication. Inspection method: visual check. Criteria: good lubricating condition.
4. Fitting. Inspection method: visual check, wrench. Criteria: no looseness, no loss of fitting bolt.
5.Leakage. Inspection method: visual check. Criteria: no water leakage.
6. Dredge pump impeller: content: damage, wear. Inspection method: touch, visual check. Criteria: no damage, no remarkable wear.
7. Dredge pump casing liner: content: damage, wear. Inspection method: touch, visual check. Criteria: no damage, no remarkable wear.
8. Dredge pump suction mouth. Content: damage, wear. Inspection method: touch, visual check. Criteria: no damage, no remarkable wear.
9. shaft, shaft bearing: Content: adjustment, wear. Inspection method: touch, visual check. Criteria: no damage, no remarkable wear.
1. Analysis of the failure of the mechanical seal of the dredge pump The shutdown of the dredge pump is mainly caused by the failure of the mechanical seal. The failures are mostly leaks. The causes of leakage are as follows: (1) Leakage of the static and dynamic sealing surfaces, mainly due to: flatness of the end face, roughness not meeting requirements, or scratches on the surface; particulate matter between the end faces, The two ends cannot be operated in the same way; the installation is not in place and the method is incorrect. (2) Compensation ring seal leakage, the main reasons are: gland deformation, uneven pre-tightening force; improper installation; the quality of the seal ring does not meet the standard; the seal ring selection is wrong. The actual use results show that the most ineffective part of the sealing element is the end face of the moving and stationary ring, the dredge pump is sealed, and the crack on the end face of the static ring is a common failure phenomenon. The main reasons are: (1) sealing surface clearance during installation If it is too large, the flushing liquid can't take away the heat generated by the friction pair; the flushing liquid leaks away from the gap of the sealing surface, causing the end surface to overheat and be damaged. (2) The liquid medium vaporizes and expands, so that the two end faces are separated by the vaporization expansion force. When the two sealing faces are pressed together, the lubricating film is broken to cause the end surface to be overheated. (3) The lubricity of the liquid medium is poor, and the operating pressure is overloaded, and the tracking and rotation of the two sealing surfaces are not synchronized. For example, the high speed pump speed is 20445r/min, the center of the sealing surface is 7cm, and the line speed is up to 75 m/s after the pump is running. When there is a sealing surface lag, the rotation cannot be tracked, and the sealing surface is damaged by the instantaneous high temperature. (4) The sealing rinsing liquid orifice plate or the filter screen is clogged, resulting in insufficient water and invalidation of the machine seal. In addition, the surface of the sealing surface is solid, and the gap is caused by the gap at the end surface. The main reasons are: (1) the liquid medium is not clean, there are tiny hard particles, and the sealing surface is swept at a high speed. The surface is scratched and fails. (2) The coaxiality of the pump transmission parts is poor. After the pump is turned on, the end face is shaken once every revolution, and the running track of the moving ring is not concentric, causing the end face to vaporize and overheat and wear. (3) Frequent occurrence of hydraulic characteristics of the liquid medium causes the pump unit to vibrate, causing the sealing surface to be misaligned and fail. Corrosion of the sealing medium by the liquid medium, stress concentration, coordination of soft and hard materials, erosion, auxiliary seal 0-ring, V-ring, concave ring and liquid medium are incompatible, deformation, etc. will cause mechanical seal surface damage failure, so The damage form should be comprehensively analyzed to find out the root cause and ensure that the mechanical seal runs for a long time.
2. Requirements after the dredge pump stops running. (1) After the dredge pump stops running, the pump's population valve should be closed. After the pump is cooled, the valve of the auxiliary system is closed. (2) The high temperature pump should be stopped according to the technical documents of the equipment. After parking, it should be half a turn every 20 to 30 minutes until the temperature of the pump drops to 50°C. (3) When the cryopump is parked, when there is no special requirement, the pump should always be filled with liquid; the suction valve and the discharge valve should be kept normally open; the cryopump with double mechanical seal, the liquid level controller and the pump seal cavity The sealing fluid should maintain the pumping pressure of the pump. (4) Pumps that transport crystals that are easy to crystallize, easy to solidify, and easily precipitate, should be blocked after stopping the pump, and flush the pump and pipeline with water or other medium in time. 5 Discharge the liquid accumulated in the pump to prevent rust and cracking.
3. Storage of dredge pump (1) Pumps that have not been installed should be coated with a suitable rust inhibitor on the unpainted surface. Bearings that are lubricated with oil should be filled with appropriate oil, grease-lubricated bearings. Only one grease should be filled, not mixed grease. (2) Pumping clean liquid, flushing, suction line, discharge line, pump casing and impeller for a short time, and draining the pump casing, the suction line and the flushing liquid in the discharge line. (3) Drain the oil in the bearing housing, add the clean oil, thoroughly clean the grease and refill the new grease. (4) Seal the suction and discharge ports, store the pump in a clean, dry place, protect the motor windings from moisture, and spray the inside of the pump casing with anti-rust liquid and anti-corrosion liquid. (5) The pump shaft rotates once a month to avoid freezing and lubricate the bearings.
Several methods for maintaining the dredging pump in a normal and economical condition to achieve the planned dredging schedule. Maintenance of dredging fleet would be remarkably improved by executing the recommendations. For dredge pump for sale, contact us at info@dopumgroup.com or call us +8615031104888 24/7 on line.
