In the modern industrial equipment system, self-balancing multistage centrifugal pumps, as core fluid conveying devices, are widely used in petrochemical, power, municipal engineering, energy development and other fields. Sudden rotor locking of such equipment may not only cause downtime losses, but also trigger chain safety accidents. In this article, technical personnel from Zoomlian Pump Industry, a professional manufacturer of self-balancing multistage centrifugal pumps, will deeply analyze the systematic causes and solutions for rotor locking of self-balancing multistage centrifugal pumps from the perspective of engineering practice, hoping to provide you with reference.
I.Common Causes in Operation Management
Not following the operation specification of "filling with liquid before starting" may lead to dry running of the impeller and thermal deformation. When some enterprises use frequency converters for control, the lack of soft start parameter setting may cause bearing displacement due to instantaneous current impact. A power enterprise once started the equipment without closing the outlet valve, resulting in damage and locking of the motor bearing.
Long-term operation beyond the flow rate will increase the radial force on the bearing. Data from a chemical project shows that when the flow rate exceeds the rated value by 15%, the bearing life is shortened by 40%. In addition, sudden changes in medium density or abnormal pipeline resistance may trigger motor torque overload protection.
II. Key Vulnerabilities in the Maintenance System
Excessively long bearing lubrication cycles or incorrect grease selection will lead to metal fatigue wear. A case in a steel plant showed that using ordinary lithium-based grease instead of special high-temperature lubricating grease caused the equipment to lock up after running for 300 hours. It is recommended to use an intelligent lubrication system for dynamic monitoring.
If mechanical seal leakage is not handled in time, the medium invading the bearing box will cause emulsification of the lubricating medium. For equipment conveying corrosive media, seal failure is more likely to cause electrochemical corrosion of the bearings.
III. Aging Mechanisms of Key Components
Excessive bearing clearance will lead to an increase in vibration values. When the vibration intensity exceeds the G2.8 level of the ISO10816-3 standard, the equipment should be shut down for maintenance immediately. It is recommended to use vibration sensors for early warning.
For every 0.1mm increase in the fit clearance between the impeller and the guide vane, the equipment efficiency decreases by 1.2%. A thermal power plant used 3D scanning technology and found that when the wear of the impeller mouth ring caused the clearance to expand to 0.8mm, the operating noise of the equipment increased by 15 decibels.
IV.Influence Factors of Medium Characteristics
When the solid content of the medium exceeds 0.5%, it is recommended to install a multistage filtration system. A mining project did not install a cyclone separator, resulting in blockage of the impeller passage and periodic locking failures.
For media with high calcium and magnesium ion content, it is recommended to use an online acid cleaning system. Dynamically adjusting the dosage of scale inhibitors based on water quality analysis data can effectively control the scaling rate.
The problem of rotor locking in self-balancing multistage centrifugal pumps is essentially the external manifestation of systematic management issues. Lishengde Pump Industry recommends that enterprises establish an operation and maintenance system of "prevention first, data-driven", and achieve reliable equipment lifecycle management through the combination of intelligent monitoring technology and professional services.