3 Typical Cases of Oil Purifier Stalling Caused by Filter Element Clogging
Industrial Hydraulic System Fault Analysis
Filter element clogging is one of the most common faults leading to stalling, flow reduction and abnormal shutdown of industrial oil purifiers. It frequently occurs in power plant EH oil systems, steel mill hydraulic stations and mobile vacuum oil purification equipment. Severe clogging will increase system oil circuit resistance, overload operating equipment, and even cause production quality defects and unit shutdown failures. This article analyzes three typical engineering cases of oil purifier stalling caused by filter blockage, including operating conditions, fault symptoms, root causes and standardized disposal solutions, providing practical reference for industrial equipment operation and maintenance.
Case 1: Filter Element Clogging Fault in EH Oil System of Thermal Power Plant
Basic Application Information
Application Scenario: EH fire-resistant oil system of 300MW thermal power generating unit
Operating Condition: 24-hour continuous operation; medium: phosphate ester fire-resistant oil
Fault Symptoms
1. The on-site pressure gauge showed that the inlet-outlet differential pressure of the filter element remained continuously over the limit, far exceeding the rated value of 10 bar.
2. The unit control valve acted sluggishly, the servo valve responded slowly and jammed with an action delay of nearly 30 seconds, and the control system frequently triggered abnormal alarms.
3. The oil outlet flow of the oil purifier decreased significantly, and the overall operating noise of the equipment increased obviously.
Fault Causes
1. The filter element was not replaced in accordance with the periodic maintenance standard and operated overdue for 28 days. The filter material was completely blocked by oil sludge, metal fine particles and oxidized colloids.
2. Ingress of water into the oil system in the early stage accelerated oil deterioration and generated a large number of sediments, which sharply increased the contamination holding load of the filter element.
3. The bypass valve was forced to open, allowing unfiltered contaminated oil to directly enter the servo control loop, resulting in system abnormal operation.
Disposal Process
1. Reduced the load of the generating unit, cut off the power supply and relieved system pressure for shutdown maintenance.
2. Disassembled the filter cylinder and took out the old filter element. The filter material was compacted and blackened with a large amount of oil sludge attached to the surface, while the sealing ring remained intact.
3. Replaced with a new HC8314FKZ39H interchangeable filter element, and comprehensively inspected the integrity of oil pipelines and valves.
4. Started the oil purifier for circulating filtration, sampled and tested the oil cleanliness. The unit was restored to full-load operation after all indicators met the standard.
Case 2: Filter Element Blockage Fault of Main Hydraulic Station in Steel Mill Hot Rolling Mill
Basic Application Information
Application Scenario: Main hydraulic station of large-scale hot rolling production line
Operating Condition: Continuous high-load operation; harsh on-site environment with excessive dust and high ambient temperature
Fault Symptoms
1. Severe pressure fluctuation occurred in the hydraulic system, resulting in unstable steel rolling accuracy and defective products.
2. The oil purifier frequently stalled and tripped during operation.
3. The filter element differential pressure alarm light was constantly on.
Fault Causes
1. Metallurgical dust and rolling scale continuously mixed into the hydraulic oil, causing the filter element to reach contamination holding capacity saturation in a short time.
2. The operation and maintenance staff ignored the differential pressure alarm, allowing the equipment to operate with faults for a long time.
3. Severe filter blockage led to a sharp increase in oil circuit resistance and excessive oil pump load, ultimately causing mechanical jamming and stalling of the oil purifier.
Disposal Process
1. Shut down the production line for a short time and closed all oil circuit valves.
2. Replaced the blocked filter element, and thoroughly cleaned dust and impurities accumulated on the inner wall of the filter cylinder.
3. Conducted a comprehensive inspection of hydraulic oil quality and started the oil purifier for online oil purification.
4. Optimized the daily inspection system: recorded the filter element differential pressure every 4 hours to realize early warning and risk prediction of filter blockage.
Filter Blockage Fault of Mobile Vacuum Oil Purifier
Basic Application Information
Equipment Type: Mobile vacuum oil purifier
Application Purpose: Offline purification and regeneration of hydraulic oil and lubricating oil in various production workshops
Fault Symptoms
1. The oil purifier had smooth oil intake but almost no oil output, with dull operating sound and obvious body vibration.
2. The internal high-temperature protection device was frequently triggered, causing automatic and intermittent shutdown of the equipment.
3. Disassembly inspection showed that the entire filter element was completely blocked, and oil could not penetrate the filter material normally.
Fault Causes
1. The equipment was used to treat multiple batches of waste oil for a long time. Impurities, paint scales and colloidal substances in the oil accumulated and hardened on the filter material surface, forming compact blockage.
2. Low-cost filter elements with mismatched filtration accuracy were adopted, which had insufficient contamination holding capacity and were prone to complete blockage.
3. The filter element was slightly offset during installation, leading to excessive local flow velocity and accelerated partial blockage of the filter material.
Disposal Process
1. Shut down the equipment for cooling and pressure relief, and removed and scrapped the failed filter element.
2. Installed high-quality interchangeable filter elements with matched accuracy and high dirt holding capacity, and corrected the installation position while checking the sealing ring condition.
3. Conducted pre-treatment on severely polluted waste oil before fine filtration to reduce filter burden.
4. Established a classified oil filtration management system to separate the treatment of heavily polluted oil and clean oil, avoiding cross-contamination and excessive filter load.
Summary
Through the above three typical cases, it can be concluded that the main causes of filter clogging and oil purifier stalling include overdue filter replacement, mismatched filter specification, poor on-site operating environment, oil deterioration and irregular operation and maintenance management. Standardized filter replacement, regular oil quality detection, optimized inspection mechanism and classified oil treatment can effectively avoid similar faults, ensure the stable operation of hydraulic and oil purification systems, and reduce industrial production losses.