Maintenance of concrete mixing plant

The Importance and Core Content of Maintenance for Concrete Batching Plant

As a key piece of equipment in construction, the stable operation of a concrete mixing plant directly affects project quality, schedule, and cost. Scientific maintenance can not only extend the service life of the concrete mixing plant equipment and ensure production quality but also improve production efficiency and economic benefits.

Its core content covers multiple dimensions such as concrete mixing plant cleaning, inspection, lubrication, fault handling, and concrete mixing plant regular maintenance, which need to be systematically carried out in combination with the concrete mixing plant usage and the manufacturer’s requirements.

Core Dimensions and Implementation Points of Concrete Mixing Plant Maintenance

• Cleaning and Maintenance
• Daily Cleaning: Clean the concrete residues in the mixing drum and conveying system every day (using high-pressure water gun flushing or manual cleaning) to prevent residual concrete from solidifying and causing blockage; regularly clean the concrete mixing plant surface (wipe with clean water or soapy water) to keep it tidy and reduce dust corrosion on components.
• Shutdown Cleaning: During the shutdown period, the interior of the concrete mixing plant must be thoroughly cleaned, along with replacing lubricating oil and checking functions, to avoid component aging caused by long-term idleness.
• Lubrication Maintenance
• Lubrication Point Management: Regularly check the grease quantity and cleanliness of each lubrication point (such as bearings, gears), determine the lubrication cycle according to the frequency of use and ambient temperature, and ensure the smooth operation of transmission components.
• Oil Replacement: Replace lubricating oil and oil filters as required to prevent oil aging or impurities from entering the hydraulic and transmission systems, which may affect equipment performance.
• Equipment Inspection
• Operation Status Check: Determine if components such as motors and reducers are abnormal by observing operation, listening to sounds, touching for vibrations, etc.; check the wear or looseness of stirring blades and stirring arms.
• System Special Inspection: For the electrical system, cables, plugs, controllers, PLC, frequency converters and other components need to be inspected to ensure that the lines are not damaged and the connections are firm; For the hydraulic system, focus on checking the oil level, oil quality, pipeline leakage, and the operating status of the pump body and motor.

Cycle and Record Specifications for Maintenance of Concrete Mixing Plant

Maintenance cycle division

Maintenance Type | Cycle | Core Content |

|————–|———-|————–|

Daily Maintenance | Daily | Clean residues, check fasteners, lubricate key parts, observe operating sound |

Regular Inspection | Weekly | Conduct a comprehensive inspection of the electrical, hydraulic, and transmission systems, and calibrate instruments and indicator lights |

Monthly/Quarterly Maintenance | Monthly/Quarterly | Replace worn parts (such as bearings, oil seals), clean the oil circuit, adjust the transmission clearance |

Overhaul | Every six months/yearly | Replace major components (such as stirring blades, gears), readjust equipment parameters, and apply protective paint |

Key Points of Maintenance Records

• Record Content: Must include maintenance time of concrete mixing plant, specific operations (e.g., “clean the mixing drum”, “replace the hydraulic oil filter element”), executor and contact information, as well as the evaluation result of equipment operation status.
• Significance: By recording the traceable historical status of equipment, it provides data support for fault diagnosis and maintenance cycle optimization, ensuring the continuity and standardization of maintenance work.

Handling of Common Failures and Maintenance of Key Components

• Typical Troubleshooting
• Motor failure: Check if the bearing is damaged and if the winding is short-circuited. Replace the bearing or repair the winding if necessary.
• Belt Problems: When deviation occurs, adjust the idler position or remanufacture the joint; for slipping, replace the worn belt or adjust the tensioning device.
• Hydraulic System Failure: For issues such as abnormal noise from the oil pump and pipeline leakage, it is necessary to check the oil level, replace the filter element, or tighten the pipeline.
• Key Component Maintenance
• Stirring Device: Regularly check the wear degree of stirring blades and stirring arms. Replace them in time when the wear exceeds the limit to avoid affecting the uniformity of concrete mixing.
• Transmission System: Lubricate and adjust the clearance of components such as gears, chains, and bearings to ensure smooth transmission and reduce mechanical loss.

Through systematic maintenance and repair, the failure rate of concrete mixing plants can be effectively reduced, ensuring long-term stable operation of the concrete mixing plant and providing reliable support for engineering construction.

The failure prevention of concrete mixing plant is a core link to ensure production continuity and reduce operating costs, which requires the establishment of systematic measures from multiple dimensions such as equipment management, operating specifications, and risk control. Combined with the common risk types and equipment characteristics of concrete mixing plant, the following elaborates specific prevention strategies from four levels: mechanical, electrical, environmental and management.

1. Preventive Measures for Mechanical System Failures

Mechanical failure is the most frequent problem in concrete mixing plant, mainly involving key equipment such as mixers, conveyor belts, and crushers. It needs to be prevented and controlled through the triple means of regular maintenance, protection upgrades, and operational specifications.

1. Standardization of Equipment Maintenance

• Regular inspection and replacement of vulnerable parts: For high-frequency wear parts such as mixer blades, conveyor belts, and bearings, formulate a monthly wear detection plan. For example, when the thickness of the conveyor belt body is less than 1/3 of the standard value, it must be replaced to avoid breakage and splashing accidents.
• Refined Management of Lubrication System: Establish a lubrication point ledger, check the grease quantity and condition of gearboxes, bearings and other parts before daily startup, and adopt the method of “oil level observation + regular sampling and testing” to ensure lubrication effect and prevent equipment damage due to dry friction overheating.

2. Upgrading of Safety Protection Facilities

• Installation of Protective Devices for Key Equipment: Detachable protective covers are set at the inlet and outlet of the mixer and the transmission parts of the conveyor belt. The operating platform is equipped with a dual-circuit emergency stop button, and the response time must be ≤ 0.5 seconds.
• Vibration and Temperature Monitoring System: Vibration sensors and temperature alarms are installed on equipment such as crushers and main mixing machines. When the amplitude exceeds 0.1mm or the temperature exceeds 80℃, the system will automatically shut down and alarm.

II. Electrical and Fire Explosion Risk Prevention

Electrical faults, fires, and explosions are major safety hazards at mixing plants, and a defense line needs to be built through source control, regular inspections, and emergency preparedness.

1. Full-cycle Management of Electrical Systems

• Circuit and Equipment Inspection: Conduct electrical circuit insulation resistance tests quarterly (required to be ≥1MΩ), focusing on checking whether distribution boxes and motor terminals are oxidized or loose; for core control modules such as frequency converters and PLC, perform dust removal and function verification every six months.
• Equipment Specifications for Explosion-Proof Areas: In flammable and explosive areas such as powder silos and oil tanks, Ex d IIB T4 explosion-proof motors are used, and cable wiring is protected by threading through galvanized steel pipes to prevent sparks from igniting dust.

2. Comprehensive Prevention and Control of Fire and Explosion

• Material Stacking and Storage Optimization: For powder silos containing materials such as cement and fly ash, the “first-in-first-out” principle shall be followed, the storage height shall not exceed 80% of the silo capacity, and pressure relief valves shall be installed on the top of the silos to prevent dust accumulation from causing explosions.
• Fire-fighting Facilities and Drills: For every 500㎡ operation area, configure no less than 2 sets of 4kg dry powder fire extinguishers, and the distance between fire hydrants ≤ 30m; conduct monthly fire drills, focusing on training for initial fire extinguishment (controlling the fire within 3 minutes) and personnel evacuation routes.

III. Prevention of Environmental and Occupational Health Risks

Dust pollution and related occupational disease risks need to be addressed through the collaborative governance of process improvement, personal protection, and environmental monitoring.

1. Comprehensive Dust Control Technology

• Whole-process Enclosure and Collection: Closed corridors are adopted for raw material crushing and conveying links; bag filters (filtration efficiency ≥ 99.9%) are installed in the mixing plant; and pulse back-blow dust removal systems are equipped on the tops of powder silos to ensure that the dust concentration in the workshop is ≤ 2mg/m³.
• Wet Dust Suppression Assistance: Set up high-pressure fog cannons (with a coverage radius ≥ 30m) in the aggregate stockyard, install spray devices at the transfer points of the conveyor belt, and control the moisture content at 6%-8% to suppress dust.

2. Health Protection for Operating Personnel

• Mandatory Wearing of Personal Protective Equipment (PPE): Frontline operators must use N95 dust masks, goggles, and anti-smashing safety shoes, replace mask filters every shift, and undergo regular lung function tests (once a year).

IV. Management System and Emergency Support

Through system construction, personnel training and emergency capacity improvement, a long-term mechanism for fault prevention is formed.

1. Standardized Management System

Equipment record management : Establish a full-life-cycle file for individual equipment, record maintenance, repair, and fault history data, and use information systems (such as ERP) to automatically generate maintenance reminders

Risk Classification and Control: Classify mechanical injury, fire and explosion as Level A risks, and conduct monthly inspections by the general manager; classify dust pollution and vehicle injury as Level B risks, which are inspected weekly by workshop directors.

2. Emergency Response Capacity Building

• Fault Emergency Response Plan: For common faults such as mixer jamming and conveyor belt breakage, a three-level disposal process of “5-minute emergency response, 30-minute temporary disposal, and 2-hour production recovery” is formulated, with a dedicated emergency repair tool kit provided.
• Cross-departmental linkage mechanism: Sign a 24-hour technical support agreement with equipment manufacturers, reserve key spare parts (such as stirring motors, PLC modules), and ensure that the arrival time of spare parts is ≤ 4 hours in case of sudden failures.

Through the systematic implementation of the above measures, the mechanical failure rate of the mixing plant can be reduced by more than 60%, the risk of fire and explosion can be reduced by 80%.