The intermittent asphalt mixing station is the core heavy equipment for road engineering and municipal maintenance. It covers seven major systems: cold material supply, dry combustion, hot material screening, mixing and weighing, asphalt supply, bag dust removal, and electrical automatic control. It has been in high temperature and high temperature for a long time. Dust, strong wear, and continuous heavy load conditions.Most construction units have the problem of "heavy production and light maintenance", which is easy to cause a series of problems such as excessive mixture quality, soaring fuel energy consumption, excessive environmental emission and shortened equipment life.In combination with industry standards and original technical specifications, this paper systematically combs the complete maintenance system of mixing station, covering six core sections: daily inspection, monthly pre-maintenance, off-season annual overhaul, high-frequency fault disposal, intelligent monitoring upgrade and full-process safety specification, which can be used by equipment managers, maintenance technicians and engineering management personnel.
.jpg)
Preventive maintenance is not an additional investment, but a core management means to reduce cost, increase efficiency, stabilize production and compliance. Standardized maintenance can realize seven core benefits:
Mixing station losses concentrated in mixing blades, lining, drying cylinder copying plate, conveying chain, dust filter bag, all kinds of bearings and other wearing parts.Through daily cleaning, regular lubrication and timely replacement of parts, it can effectively resist material friction and high temperature corrosion, avoid aging and cracking of main structures such as cylinders, stirring hosts and silos, avoid high overhaul and replacement costs of the whole station, increase the service life of equipment by more than 30%, and significantly improve the return on fixed assets.
Road construction is very seasonal, and sudden failure of equipment in peak season will directly cause shutdown of the whole paving line, resulting in idle equipment, labor waste, period breach and other losses.Daily inspection can check hidden dangers such as bearing lock, bag blockage, belt damage, burner failure, etc. in advance, and make use of shutdown window for planned maintenance to completely avoid the risk of sudden shutdown.
Stable mixture finished product quality
Acceptance indicators such as mixture ratio, discharge temperature, mixing uniformity, etc., completely depend on the stable operation of each system.Lack of maintenance is easy to cause sensor drift, screen damage, combustion imbalance, mixing gap exceeds the standard, causing mixture segregation, poor coating, waste rate and other problems.Regularly calibrate equipment and overhaul core units, continuously output compliant finished materials, and greatly reduce raw material loss.
Reduce consumption and cost, reduce operating expenses
Fuel oil is the largest variable cost of mixing station, the wear of material plate, poor atomization of burner, dust removal and abnormal heat dissipation of equipment will increase fuel consumption by 15%-25%.Normalized maintenance can optimize heat exchange efficiency, reduce equipment load, and save fuel and electricity costs; at the same time, preventive maintenance can reduce spare parts and labor costs by more than 50% compared to fault repair.
Ensure environmental protection compliance production
Bag dust removal is the core of environmental protection control, filter bag damage, ash removal failure, air duct leakage blockage, will cause dust, flue gas emission exceeds the standard, causing fines, shutdown rectification.Normalized maintenance of dust removal system, stable pressure difference and dust removal efficiency, ensure that exhaust gas dust emission standards, stable environmental protection production qualification.
Eliminate potential safety hazards of equipment
Mixing station has multiple risks such as high temperature operation, high speed machinery, high voltage electricity, high altitude closed operation, etc. Line aging, pipeline leakage, overheating of components, lack of protection are easy to cause burns, mechanical injuries and fire accidents.Regular inspection and maintenance, perfect safety protection, can eliminate most of the potential safety hazards from the equipment end.
Stabilize production capacity and continue to output
Standardized maintenance achieves four-dimensional stability in production capacity, quality, safety, and environmental protection, improves the effective production time of equipment, ensures continuous supply of projects, and enhances Party A's reputation for cooperation.Complete maintenance ledger can support asset inventory, bidding qualification review, and assist long-term operation of enterprises.
Daily maintenance is divided into pre-shift and post-shift two-stage operation, all contents shall be entered into equipment account, hidden dangers shall be marked and rectified in time; LOTO energy isolation shall be implemented for maintenance movement and high temperature parts, and labor protection appliances shall be worn in the whole process.
Safety inspection and on-site environment inspection of the whole station
Visually check hidden dangers such as pipeline leakage, abnormal noise and vibration of equipment, abnormal smoke exhaust, cylinder deformation, etc., and confirm that the protective cover, emergency stop button and limit switch are in good condition and effective.Clean platform, ladder and ground caked oil, eliminate slip and trip risk, check compliance and availability of fire fighting equipment and first aid materials.
Whole system cleaning operation
Clean the residual mixture of mixing tank, blade and discharge door to prevent agglomeration and stagnation.Clean the belt and chute to avoid belt deviation and damage.Empty the hot hopper and weigh the remaining materials to prevent the old and new materials from mixing and affecting the grading.Gently purge the dust from the electronic control and sensor. It is forbidden to blow the precision electrical components directly with high pressure wind.
Lubrication and hydraulic and pneumatic medium inspection
Visually inspect the oil level of reducer and hydraulic oil tank, fill corresponding oil according to the standard, and prohibit oil mixing.Fill high temperature grease for high temperature bearings and drive pin shafts, and strictly control the grease injection amount of motors to avoid overheating.Check the air pressure system, empty the reservoir, trap water, prevent corrosion and winter frost crack gas circuit.
Cold material conveyor, elevator feeding system inspection
Check belt tightness, wear, ensure that the roller, cleaner is in good condition.No-load operation hoist, scraper, monitor abnormal noise and tighten hopper bolts.Clean up cold bin, RAP bin wall hanging lumps, ensure smooth blanking without blocking.
Drying drum and combustion system
Observe the flame shape, orange yellow is normal, black smoke, flicker is air-fuel ratio imbalance.Check whether fuel pipeline and filter have leakage, cylinder has no accumulated material, supporting wheel and blocking wheel operate smoothly.Monitor exhaust gas temperature and furnace negative pressure, and record and report abnormal data in time.
Mixing and asphalt weighing supply system
Start up to clear and peel all weighing equipment, check sensor sensitivity, clean up accumulated materials and stuck materials.Make sure the mixing parts run smoothly and the discharge door seals are intact.Check asphalt pump, pipeline and nozzle for leakage, stabilize temperature of storage tank and heat transfer oil, and meet process standard.
Bag dust removal environmental protection system
Real-time record dust box pressure difference, pressure difference rise is filter bag clogging warning.Check whether pulse ash cleaning and blowing pipe are in normal operation, air duct and access door are tightly sealed without air leakage.The induced draft fan operates without abnormal noise and vibration to ensure the dust removal system is stable and up to standard.
Electrical automatic control system
Test indicator lamp, fault alarm and safety interlock function to ensure sensitivity and reliability.Check the data of each sensor and check the abnormal error of equipment.No-load test motor start-stop logic to confirm that interlock protection is triggered normally.
Maintenance records after production
Record the output of the day, abnormal noise of equipment, leakage and other abnormalities, mark weekly and monthly maintenance items, and form a maintenance list.Strictly implement shutdown process, empty mixing cylinder, prolong induced draft fan heat dissipation, and power off step by step after drum temperature drops below 90℃.
Monthly maintenance is carried out once a month or every 150 - 300 hours of operation (whichever comes first), and centralized maintenance is required. All test data and replacement records are archived, and the original torque and lubrication standards are strictly observed.
Deep maintenance of mixing host
Measure the gap between blade and lining plate, standard 3 - 5mm, adjust or replace accessories in time if exceeding the standard.Check mixing arm, shaft end floating seal, aging leakage immediately replace seal assembly.Check lubricating oil quality of reducer, change oil thoroughly for emulsion and metallic debris.High pressure cleaning cylinder volume carbon agglomeration, check weld wear, cracking hidden danger.
Special maintenance of drying drum and burner
Check the wear, deformation and absence of material copying plate in the drum, repair or replace the welding of serious parts.Ultrasonic inspection of barrel wall thickness, marking of thinned areas and preparation of repair welding schedule.Adjust the supporting wheel and blocking wheel to ensure concentric operation and uniform force of the roller.Disassemble and clean the burner nozzle and filter element, calibrate the air-fuel ratio and improve the combustion efficiency.Repair the insulation layer of the cylinder and seal the layering to reduce the heat leakage loss.
Vibrating screen and hot aggregate system maintenance
High-pressure cleaning screen plug aggregate, replacement of damaged screen.Check damping rubber block, compression attenuation exceeds 20%, forced replacement.Fill high-temperature grease into the vibration motor bearings and test the equipment temperature rise and vibration amplitude.Clean up hot bin caking, check gate and level gauge to ensure smooth opening and closing and accurate signal.
Maintenance of conveying and lifting equipment
Check the wear, crack and joint status of belt, adjust tension, replace invalid idler and cleaner.Check the hoist chain, hopper, chain wheel wear stretch, timely cut or replace.Check scraper bottom plate, liner wear, repair leakage gap, replace damaged sealing skirt.
Deep maintenance of bag dust removal system
Check filter bags and frameworks one by one, replace torn, pasted bags and damaged filter bags.Clean dust in air duct and ash hopper, and seal air leakage gap of box body.Full-function test pulse valve, differential pressure switch, replace slow leakage valve body.Clean dust deposit on impeller of induced draft fan, correct dynamic balance, fill bearing grease and eliminate vibration hidden danger.
Bitumen supply and heat transfer oil system
Drain the impurities deposited at the bottom of asphalt tank, flush and dredge blocked pipeline.Check the working condition of heat conduction oil furnace and heating coil, repair damaged insulation layer.Disassemble and clean asphalt pump, metering valve and filter to solve the problems of blockage and metering misalignment.Calibrate temperature sensors and instruments to eliminate temperature deviation.
Weighing measurement and automatic control system calibration
Use standard weights to calibrate the full range of aggregate, mineral powder and asphalt scales, and strictly control weighing errors.Clean up the sticky materials in the weighing hopper to prevent the drift of weighing caused by accumulated materials.Clean and calibrate all kinds of sensors and replace distortion probes.Fasten the terminals of the electric control cabinet, check the aging and heating of the circuit, and test the interlocking and alarm functions.
Lubrication of the whole machine and inspection of transmission fasteners
Uniformly add suitable grease to the high-temperature bearings and transmission pins of the whole station to eliminate lubrication blind areas.Check the oil quality of reducer and hydraulic station, and change oil thoroughly when it is due.Check the wear of coupling, chain and sprocket wheel, correct the misplaced parts.Focus on tightening bolts in vibration areas such as screening machines, rollers, and silos to ensure the stability of the equipment.
Maintenance ledger and spare parts planning
Filing wear data, oil testing, replacement records.According to the law of wear and tear to supplement blades, filter bags, bearings and other vulnerable parts inventory.Sort out the hidden dangers of major equipment, formulate overhaul plan, review daily accounts and optimize the maintenance frequency of high-frequency faults.
Off-season maintenance is carried out for winter shutdown and project gap period, and annual overhaul is carried out once a year. The combination of the two focuses on eliminating accumulated wear throughout the year, and complex procedures such as high-precision adjustment and cylinder flaw detection shall be operated by certified personnel for stable production in the coming year.
Final maintenance before shutdown
Thoroughly clean up the machine residue to prevent caking corrosion equipment.Strictly implement the cooling shutdown process, and the drum temperature can be cut off only when it drops below 90℃.Drain water and air pressure pipeline to prevent freezing.The shutdown equipment shall be evacuated with asphalt or circulated for heat preservation to avoid pipeline solidification and blocking.Bare metal rust repair paint, electric control, motor waterproof and dustproof, put equipment desiccant moisture, storage accessories and cut off water, electricity, oil, gas source.
Key maintenance points during off-season shutdown
Flaw detection and thickness measurement of drying drum, repair of material copying plate, correction of concentricity of supporting wheel and blocking wheel.Replace the worn lining plate, blade and shaft end seal of the mixing main engine, and repair the gear box.Replace dust filter bag aging, clean dust air duct, maintain fan, correct dynamic balance.Disassemble and adjust the combustion system to optimize combustion efficiency.Repair welding to reinforce worn parts of silos, access gates and cylinders.Replace worn belts, chains and bearings of conveyor lifting system.The whole station reducer unified oil change, excessive bearing synchronous replacement.Clean regeneration system caking, repair lining plate.Check electrical wiring, calibrate sensors, prevent moisture short circuits.Steel structure derusting, paint repair, reinforcement of weld brackets.
Core contents of annual comprehensive overhaul
Annual overhaul is the deep disassembly and overhaul of the whole machine, and nondestructive inspection and wall thickness inspection are carried out on the drum, bin and bearing support to predict structural damage.Batch replacement of high-wear parts of the whole machine, correction of dynamic balance of fans, rollers and vibrating screens, elimination of excessive vibration problems.Detect combustion conditions, analyze flue gas parameters, optimize combustion strategy to reduce fuel consumption.The entire line of legally calibrated weighing systems ensures that measurement accuracy meets standards.Disassemble and repair reducer, hydraulic system, replace aging oil seal, gear and pneumatic seal.Upgrade automation system firmware, complete test automation logic and alarm program.Summarize the annual maintenance files, analyze the wear law of accessories, optimize the maintenance plan for the next year, simultaneously carry out safety training for all personnel, and update the standardized operation process.
Most of the faults in the mixing station are caused by insufficient cleaning, lack of lubrication, calibration lag and extended service of wearing parts. The following are the high-frequency faults and accurate treatment schemes on the construction site.
Excessive temperature fluctuation of mixture discharge
Batch temperature fluctuates, overheating smoke or low temperature agglomeration.The causes include unstable aggregate moisture content, uneven cold material feeding, carbon deposition in burner, imbalance of air-fuel ratio, air leakage and insulation damage of cylinder, sensor drift and poor wear and heat transfer of material copying plate.Disposal: stable raw material stacking drainage, balanced feeding; monthly cleaning of burners, adjustment of air-fuel ratio; sealing of leakage air, repair of insulation; regular calibration or replacement of temperature sensors; timely replacement of worn material copying plates.
Weighing is inaccurate, graded oil stone ratio exceeds standard
Finished material ratio is not up to standard, acceptance is unqualified.Cause: material accumulation in scale bucket, sensor not calibrated, material leakage from discharge door, vibration damage to weighing module, asphalt pipeline blockage.Disposal: daily clearing, monthly weight calibration; replacement of aging seals; addition of shock absorption protection in weighing areas; regular cleaning of asphalt filtration and metering pipelines.
Poor mixing quality and incomplete segregation coating
Loose mixture, partial oil, serious paving segregation.Cause: mixing gap exceeds standard, screen broken gradation disorder, hot bin segregation, mixing time is insufficient, asphalt temperature control is abnormal.Disposition: strictly control 3 - 5mm mixing gap, timely replacement of wear parts; regular replacement of screen; stabilization of material level, optimization of mixing procedures; calibration of asphalt temperature control system.
Actual production capacity is lower than design value
Production cycle is lengthened and hourly output is insufficient.Cause: high water content of aggregate, blocking of sieve chute, wear and heat transfer inefficiency of copying plate, blocking of conveying equipment.Disposal: strictly control the moisture content of raw materials; dredge and screen the feeding system daily; repair and replace the copying plate monthly; optimize the arch-breaking device to ensure continuous blanking.
Fuel consumption is soaring abnormally
Fuel consumption continues to rise at the same capacity.Cause: burner atomization poor carbon deposition, cylinder air leakage insulation damage, low efficiency of heat transfer plate, high moisture content of aggregate.Disposal: Regularly clean the nozzle, adjust the combustion parameters annually; repair the cylinder seal and insulation; replace the wear-resistant parts on time; strictly control the quality of raw materials.
High dust removal pressure difference, dust exceeding standard
Pressure difference continues to rise, chimney and site dust is obvious, filter bag is easy to be damaged.Cause: filter bag tear, pulse ash removal failure, air leakage, smoke condensation, filter bag type mismatch.Disposal: monthly replacement of damaged filter bags, testing of ash cleaning procedures; comprehensive plugging of air leakage points; control of raw material moisture to reduce condensation; replacement of temperature resistant filter bags according to operating conditions.
Conveyor lifting equipment deviation blocking material tearing
Belt deviation scattering material, tearing, elevator abnormal sound, hopper loose fall off.Cause: uneven belt tension, idler jam, cleaner failure, partial loading, insufficient chain lubrication stretching.Disposition: daily adjustment of tension, replacement of wear cleaner; regular blanking position; monthly lubrication chain, detection of tension and timely maintenance.
Stirring host abnormal noise vibration, shaft end leakage asphalt
Loud operation noise, machine vibration, shaft end leakage.Cause: wear parts collision, seal aging lack of grease, bearing reducer wear, base bolt loose.Disposal: Regularly calibrate the mixing gap, replace the wear parts and seal assembly; add sealing grease normally; detect the oil and bearings, and tighten the bolts of the whole machine.
Electrically controlled sensor error, no reason to stop
Frequent failure, interlock stop, parameter distortion.Cause: sensor dust moisture, loose line terminals, electrical control cabinet dust short circuit, voltage fluctuations.Disposal: daily purging of electronic control and sensors; monthly fastening terminals, replacement of aging lines; installation of moisture-proof dust and voltage stabilizing devices.
Bearing motor abnormal temperature rise abnormal sound
Rotating parts hot, friction abnormal sound.Cause: lubrication is not in place, bearing wear, parts are not concentric, bolts loose, rotor imbalance.Treatment: strictly implement lubrication plan; regular temperature measurement and vibration measurement; tighten fixing bolts; annual calibration equipment dynamic balance.
Traditional fixed-cycle maintenance has hysteresis, and digital IoT systems can realize predictive maintenance, from passive repair to active prediction, greatly reducing downtime losses.
State prediction and accurate maintenance
Temperature and vibration sensors are installed in bearings, reducers, motors, supporting wheels and vibrating screens. Dust removal and combustion systems collect pressure difference, temperature and air volume data. The platform is monitored in real time for 24 hours. AI analyzes wear trend, predicts hidden dangers such as locking, blockage and combustion attenuation in advance, and accurately arranges maintenance, which can reduce unplanned downtime by more than 70%.
Real-time abnormal warning
The system is equipped with visual kanban, automatic alarm in case of abnormal temperature, pressure difference, current and pressure, intervention in the initial stage of fault, reducing maintenance difficulty and parts loss.
Work order automation, spare parts intelligent control
Docking equipment management system, hidden danger automatic generation maintenance work order, closed-loop trace.The system counts wearing parts consumption according to output, automatically reminds procurement with inventory warning, eliminates downtime and missing parts, and supports multi-site cloud integrated management.
Process optimization, reduce equipment wear
Real-time monitoring of aggregate water content, air-fuel ratio, discharge temperature, automatic optimization of feeding and combustion parameters, stable production conditions, reduce equipment overload and frequent fluctuation loss, synchronous statistics of energy consumption data, positioning inefficient operation nodes.
Electronic ledger, compliance traceability
Automatically record production data, equipment parameters, maintenance records, replacement ledger, replace handwritten data, meet the needs of environmental verification, quality audit, safety inspection and asset inventory.
There are risks of high temperature, rotating machinery, high voltage electricity and high-altitude closed operation in the maintenance of mixing station. Standardized safety procedures must be implemented to prevent illegal operation.
LOTO locking and tagging energy isolation
Cut off all electric, liquid, gas and heat source energy before maintenance of moving and high temperature parts, lock and tag by special personnel, and unlock by oneself.After the repair is completed, it can be restored after confirming that there is no one on site and no tools.Short circuit interlocking and removal of protective cover are strictly prohibited.The transmission shaft must be mechanically locked inside the cylinder block and drum to prevent accidental rotation.
PPE protection for working condition matching
Wear safety helmet, reflective tooling and anti-smashing shoes for basic operation; wear high temperature resistant gloves and anti-splash surface screen for high temperature operation; wear dust mask and goggles for dust cleaning and polishing; wear ear cover in high noise environment; wear safety belt for working at height; use insulating protective equipment for electrical maintenance.
High temperature fuel fire risk control
High temperature equipment can be repaired only after sufficient cooling, flammable solvents are strictly prohibited to scrub high temperature parts.Hot work must be invoiced, gas test qualified, complete with fire equipment.It is forbidden to pour cold water directly into high temperature asphalt to prevent steam explosion. Stop immediately to plug pipeline leakage and clean up accumulated oil.
Specification for working at heights and in confined spaces
Maintain three-point support for working at heights, and add temporary protection when removing guardrails.Mixing tank, bin, dust removal box and drum belong to limited space. Ventilation and gas detection shall be arranged before operation. Emergency equipment shall be equipped and escape plan shall be implemented.
Safety control of rotating mechanical conveying equipment
All protective covers must be restored after maintenance, and it is forbidden to clean the belt and chain pinch point area by hand.Heavy accessories lifting use standard lifting equipment, manual brute force handling is prohibited.Before commissioning, confirm that there is no person or sundries on site.
Special requirements for electrical maintenance
High-voltage operation is limited to licensed electricians, and live maintenance is strictly controlled.The electric control cabinet shall be kept dry and ventilated, the damaged circuit shall be powered off and replaced immediately, and the grounding protection shall be implemented throughout the whole process to avoid the risk of electric leakage and electric shock.
Occupational health protection
Wet dust suppression or exhaust equipment shall be adopted for ash cleaning operation, gas mask shall be worn in confined space when smoke exceeds standard, and all chemicals shall be operated strictly according to SDS specification.
On-site pre-risk management and control
Carry out pre-shift risk disclosure before maintenance, and sort out hidden danger points.Ensure smooth operation and emergency passage, and it is strictly prohibited to simplify safety process in order to catch up with the construction period.All hidden dangers and near accidents shall be registered and re-listed, and the operation standards shall be continuously optimized.
Asphalt mixing station maintenance is a complete system of "daily inspection, monthly maintenance and loss control, annual overhaul and elimination, intelligent prediction and efficiency enhancement, and safety specification".Abandoning passive repair thinking and establishing standardized preventive maintenance mechanism can effectively reduce comprehensive costs such as energy consumption, accessories and shutdown, stabilize mixture production quality, ensure environmental protection and safety production compliance, maximize the service life of equipment and improve the overall operation benefit of equipment.The construction management party can combine the complete system of this paper, adapt to the working conditions of its own equipment, implement standardized maintenance accounts and operation procedures, and realize long-term stable and low-cost operation of equipment.
.jpg)
.png)
