As a core piece of equipment for solid-liquid separation in drilling engineering, the stable operation of drilling fluid centrifuges directly affects drilling efficiency and cost control. However, the high-speed, high-load working environment makes them susceptible to wear, therefore, scientific and standardized maintenance is crucial. This article will systematically outline the key precautions for centrifuge maintenance from five dimensions: daily inspection, lubrication management, safe operation, environmental adaptation, and fault prevention.
Daily Inspection
Structural Stability Check
Before starting each day, ensure that all nuts, bolts, and washers are secure and that the protective cover is firmly fixed to prevent parts from falling off due to vibration. For example, the six half-moon discs on the large end face of the drum must be installed in their original positions according to their numbers; arbitrarily swapping them will disrupt the dynamic balance and cause severe vibration. In addition, check whether the inlet pipe is bent due to impact; friction with the drum will accelerate wear or even cause breakage.
Transmission System Monitoring
Observe whether the coupling, belt, and other transmission components are jammed or abnormally worn, and adjust the belt tension regularly. During startup, the drum should rotate synchronously when the main drive motor reaches 80%-90% of its maximum speed. If there is a delay, stop the machine immediately and check the coupling oil level or drum jamming. The coupling operating oil temperature must not exceed 90℃. Overload will cause the fusible plug (melting temperature 125℃) to melt and spray oil; in this case, replace the fusible plug with one of the original specifications. Do not use bolts as a substitute.
Separation Effect Evaluation
The separation efficiency is judged by the sand discharge status: If the discharged sand is a continuous, thin, muddy flow, the load is moderate; if large clumps of dry sand are discharged intermittently, it indicates that the drilling fluid sand content is too high, and diversion is necessary to avoid the main bearing or differential temperature exceeding the limit (main bearing ≤70℃, differential ≤50℃). If the inlet drilling fluid viscosity exceeds 38 seconds, dilute with water to below 35 seconds to optimize the separation effect.
Lubrication Management
Lubrication Points and Cycles
The centrifuge has four lubrication points: For the two main bearings, add #2 lithium-based grease every 100 hours of operation until overflowing; for the screw conveyor bearing, apply grease 10 times every 50 hours using a grease gun; for the differential, use N22 hypoid gear oil in winter and N28 oil in summer, change the oil after the first 150 hours of operation, and then change and clean the internal cavity every 500 hours thereafter; for the hydraulic coupling, change to #20 or #30 turbine oil every 5000 hours, keeping the oil level between 60% and 80% of its capacity.
Lubrication Operation Procedures
When adding oil to the main bearings, open the drain plug to prevent old oil residue; after adding oil to the differential, rotate it to a 45° horizontal angle, ideally until the oil just overflows; the coupling oil must be filtered through a 100-mesh filter to prevent impurities from damaging components. For example, in one oil field, the differential was not cleaned, causing the magnetic plug to attract a large amount of iron filings, leading to gear wear and increasing repair costs by tens of thousands of yuan.
Safe Operation
Start-up and Shutdown Sequence
Strictly follow the start-up sequence of ‘Auxiliary Machine → Main Machine → Liquid Supply Pump,’ and reverse the operation when shutting down. Before the first start after a long period of inactivity, inject clean water through the flushing connector and run for 1 minute to dissolve any remaining filter cake in the drum and prevent vibration caused by imbalance during high-speed rotation. After shutdown in winter, unscrew the drain bolt at the large end of the drum to drain the liquid and prevent freezing and cracking.
Operational Prohibitions
Never open the drum or belt guard while the machine is running to prevent fingers or tools from being caught in the rotating parts. When cleaning the nozzle at the small end of the drum, do not insert your fingers into the hole, as the screw conveyor may still be rotating. For example, a maintenance worker cut his finger by inserting his finger into the nozzle before shutting off the auxiliary machine, a lesson learned the hard way.
Environmental Adaptability Adjustment
Ensure the tank surface is rigid during installation to avoid resonance; the sand discharge trough must extend outside the tank and be kept unobstructed to prevent solid phase accumulation from clogging the drum’s sand discharge port. In winter, steam preheating equipment is required, but the preheating time should not be too long to prevent aging of the seals. IV. Fault Prevention
Regular Calibration and Replacement
Inspect and tighten connecting bolts every 1000 hours, and replace fatigued or loose belts; change the hydraulic coupling oil annually and clean impurities adsorbed by the magnetic plug; clean the differential magnetic plug every 150 hours to prevent iron filings buildup. For example, a drilling team’s failure to change the coupling oil in time led to overheating, triggering a protection shutdown and delaying the project by 24 hours.
Component Protection and Corrosion Prevention
Protect vulnerable parts such as inlet pipes and nozzles during handling to avoid impacts; non-stainless steel components require regular anti-corrosion treatment, and should be stored on elevated bases and covered with rainproof cloths. Place desiccant in the centrifuge chamber when the equipment is idle to prevent metal parts from rusting.
Maintenance of drilling fluid centrifuges is a systematic project that requires attention to detail and the development of personalized solutions based on equipment operating parameters and environmental conditions. By strictly implementing daily inspections, precise lubrication, safe operation, and fault prevention measures, equipment reliability can be significantly improved, service life extended, and a solid guarantee provided for the efficient and safe operation of drilling projects.
