Modified asphalt equipment is the core special equipment in road infrastructure and asphalt processing engineering. It is mainly used for shearing, grinding, heating, storage and transportation of SBS, rubber, latex and other modified asphalt.The equipment is under the bad working conditions of high temperature, high viscosity, dust and large load fluctuation for a long time. If the maintenance is not in place, it is easy to cause problems such as pipeline blockage, shear wear, temperature control failure, equipment oil leakage and uneven discharge, which will not only reduce the production quality of modified asphalt, cause material waste, but also greatly shorten the service life of the equipment, increase the maintenance cost and the risk of delay in the construction period.Scientific and standardized maintenance is the key to ensure stable operation of equipment, improve production efficiency and reduce operation and maintenance costs.Combined with practical operation experience, this paper sorts out a complete set of maintenance skills of modified asphalt equipment, covering daily maintenance, regular maintenance, wearing parts maintenance, seasonal storage and pit avoidance errors.

Daily start-up & shutdown maintenance: must be done every day to eliminate the accumulation of minor faults

Daily maintenance is the basis for stable operation of equipment, running through the whole process of each startup production and shutdown, simple operation but vital, which can effectively avoid 80% of common equipment failures.

check before starting, check hidden dangers in advance

Before starting up every day, complete all-round pre-check: first check whether the equipment circuit, control system and temperature control instrument are normal, the circuit is free from aging, damage and looseness, and the temperature control value is calibrated correctly to avoid asphalt aging and coking caused by temperature control.Secondly, check the hydraulic system and lubricating system to confirm that the hydraulic oil and lubricating oil level are in the standard range, without leakage and lack of oil, so as to ensure the smooth transmission and operation of the equipment.At the same time, check the status of pipes, valves and seals to ensure that pipes are free of blockage, valves are flexible to open and close, flanges are tightly sealed, and leakage problems are eliminated.Finally, put the equipment into no-load trial operation to observe whether the shearing machine, grinding machine, and transfer pump are running smoothly, and whether there is any abnormal noise, shaking, or abnormal temperature rise. After confirming that there is no error, the materials can be put into production.

Inspection in production, real-time control of working conditions

During the operation of the equipment, special personnel shall be arranged for real-time inspection, focusing on monitoring three core parameters: temperature, pressure and rotation speed.The heating temperature shall be controlled strictly according to the modified asphalt production process standard, so as to avoid carbonization and coking of asphalt caused by local overheating, or uneven dispersion of modifier caused by too low temperature and viscous material blocking pipe.Always pay attention to equipment operating pressure, prevent overpressure operation, prevent pipeline and pump body damage.At the same time, observe the vibration and noise changes of the equipment. In case of abnormal noise, violent shaking, uneven discharge, etc., it is necessary to stop the machine immediately for inspection. It is forbidden to operate with faults.In addition, during the production process, it is necessary to ensure the normal operation of the equipment cooling system, timely clean up the dust and sundries accumulated in the radiator fins and vents, and avoid overheating and overload of the equipment.

Clean after shutdown to prevent material residue solidification

Modified asphalt viscosity is very strong, the residual material after shutdown is easy to cool and solidify, blocking pipes, grinding chamber and pump body, is the main cause of equipment failure.After each production, the equipment must be cleaned thoroughly in time: special cleaning oil and diesel oil shall be used to clean the shearing chamber, grinder, conveying pipeline and asphalt pump circularly, and the residual asphalt and modifier residue inside shall be thoroughly removed.After cleaning, drain the residual cleaning solution inside the equipment to avoid corrosion of equipment parts by residual liquid.At the same time, clean up the dust, oil and debris from the equipment body, console and heat dissipation parts to keep the equipment clean and dry.Finally, turn off the power supply and air source, check the reset of each valve, and make a good record of equipment operation and maintenance on that day.

Periodic in-depth maintenance: frequency maintenance, extend equipment life

In addition to daily maintenance, weekly, monthly and quarterly periodic in-depth maintenance plans shall be formulated according to the frequency of equipment use and operating load, so as to investigate hidden faults and repair worn parts in a targeted manner to ensure long-term stable operation of equipment.

Weekly maintenance: fastening inspection, oil supplement calibration

After weekly operation, tighten and check the whole equipment, check the body bolts, flanges, couplings and other connecting parts one by one, tighten loose parts, and replace slightly corroded and damaged fasteners.Check the grease status of each lubricating point, supplement special lubricating oil and grease to bearings, transmission gears, rotating shafts and other operating parts to prevent dry wear.At the same time, calibrate the temperature controller, pressure gauge, tachometer and other instrument data to ensure accurate equipment parameters and ensure that the modified asphalt production ratio and temperature meet the standard.In addition, check the filtration system, clean up the filter screen blocked debris, to avoid poor material filtration affect the discharge efficiency.

Monthly maintenance: system inspection, loss repair

Carry out systematic equipment maintenance once a month, focusing on the inspection and maintenance of core systems.In terms of heating system, check the working state of heating pipe and heat transfer oil pipeline, check whether there is deterioration and carbon deposition in heat transfer oil, clean coking layer of heating pipeline, and ensure uniform and efficient heating.In terms of hydraulic system, check the quality of hydraulic oil, replace it in time if it is turbid, deteriorated or contains too much water, clean the filter element of hydraulic oil tank, and check the jamming and leakage problems of hydraulic valve set.In terms of transmission system, check the tightness of belt and chain, adjust it to standard state, and replace aged, cracked and loose transmission accessories.At the same time, comprehensively check the equipment seals, replace the aging, deformation, leakage of the seal ring, gasket, to eliminate oil leakage, leakage problems.

Quarterly/annual maintenance: deep disassembly, complete machine maintenance

After the equipment is shut down every quarter or year, it is necessary to carry out in-depth disassembly maintenance.Disassemble the core parts of shear machine and grinding machine, check the wear degree of shear knife and grinding plate, polish and repair the slightly worn parts, replace the parts with serious wear and excessive gap in time, and avoid the grinding fineness of modified asphalt not reaching the standard and poor modification effect due to the wear of parts.Disassemble and clean the stubborn coking and carbonization layer inside the pipeline and tank, and dredge the dead corner blocking position.Carry out special inspection on core power components such as motor, reducer, asphalt delivery pump, etc., check insulation of motor, gear wear of reducer, replace aged bearings and sealing components.At the same time, anti-corrosion treatment shall be carried out on the whole equipment, and anti-rust paint shall be applied to avoid corrosion and aging of equipment.

The core wearing parts special maintenance: accurate maintenance, reduce downtime

Most of the failures of modified asphalt equipment are concentrated in wearing parts. Targeted special maintenance of wearing parts can greatly reduce the equipment failure rate and improve production continuity.
1, shear, grinding components: as the core of the equipment working parts, long-term high-speed shear, grinding materials, wear speed is the fastest.Daily need to ensure adequate lubrication of equipment, no hard impurities into the material, to avoid sand, metal particles wear tool, grinding.Check grinding clearance regularly, adjust accurately according to production requirements, and strictly prohibit overload and over-speed operation.Set up accounts for wearing parts, replace them in time when they reach their service life, and avoid using them with defects to affect the quality of asphalt modification.
2, seals, valve components: seals, packing, solenoid valves, manual valves long-term contact with high temperature viscous asphalt, easy to aging, adhesion, failure.Regular inspection of sealing performance, high temperature conditions preferred to use high temperature, oil resistance, corrosion resistance of special sealing accessories.Clean valve core residual materials during each shutdown to prevent valve core stagnation, loose closure, leakage and material stringing problems.
3, asphalt pump, transportation pipeline: asphalt pump is the core of material transportation, long-term transportation of high-viscosity materials prone to card, wear.Daily need to ensure that the pump body lubrication is good, it is forbidden to idle, dry run.Regularly clean the coking on the inner wall of the pipeline, check whether the pipeline is deformed and damaged, and replace the aging pipeline in time to prevent the pipeline from blocking and cracking.
Fourth, seasonal and long-term downtime maintenance: avoid idle loss
In case of off-season, seasonal shutdown or long-term idle of equipment, wrong storage method will lead to equipment corrosion, aging of parts and pipeline blockage, which will greatly reduce equipment performance. Special sealing and maintenance shall be carried out.
High temperature summer: equipment continuous operation easy high temperature overload, need to strengthen the maintenance of the heat dissipation system, regularly clean the heat dissipation equipment dust, check the cooling system operating status, avoid equipment high temperature shutdown.At the same time, avoid long-term high temperature deterioration of heat transfer oil and lubricating oil, and shorten the oil replacement cycle as needed.
Low temperature winter: asphalt is easy to solidify and agglomerate in low temperature environment. After shutdown, residual materials in equipment and pipeline must be completely emptied. Equipment insulation and antifreeze measures shall be taken throughout the process to prevent freezing crack and blockage of pipeline and pump body.Preheat the equipment in advance before starting the machine. It is forbidden to start the load operation directly at low temperature to avoid damage to the parts by force.
Long-term idle shutdown: thoroughly clean all material residues inside the equipment, empty all kinds of oil products and cleaning solutions, apply rust prevention grease to bearings, gears and exposed metal parts, and do a good job of rust prevention and corrosion prevention.Close all valves and power supply, seal the equipment with dust cover, store in dry, ventilated and non-corrosive environment, and prohibit exposure to the sun and rain.During the idle period, start the machine regularly for no-load test run to avoid component jamming and aging failure.

Maintenance taboos and common mistakes, effectively avoiding equipment damage

1. It is forbidden to stop with materials and long-term residual materials: after the materials are cooled and solidified, they will block the pipeline and wear the core components, which will greatly increase the difficulty of later maintenance.
2, prohibit overheating, overpressure, overload operation: illegal operation will accelerate the aging and wear of parts, it is easy to cause equipment failure, material scrap, and even safety accidents.
3. It is forbidden to mix oil products and inferior accessories: it is necessary to use the heat transfer oil, lubricating oil and sealing accessories specified by the original equipment. The inferior oil products are easy to coke and corrode the equipment, and the poor adaptability of inferior accessories is easy to cause leakage and wear problems.
4, prohibit with fault operation, delay maintenance: small abnormal sound, small leakage, slight blockage if not handled in time, will gradually evolve into a major failure, increase high maintenance costs and period loss.

SUMMARY

The core of maintenance of modified asphalt equipment lies in "daily fine cleaning, periodic in-depth maintenance, timely replacement of vulnerable parts, idle scientific storage".Standardized and normalized maintenance work can not only effectively ensure stable production quality of modified asphalt and efficient operation of equipment, but also maximize the service life of equipment, reduce maintenance costs, and reduce downtime losses.For engineering construction enterprises, establishing standardized equipment maintenance accounts and standardizing operation habits of operators are important core means to improve equipment utilization rate, ensure efficient promotion of projects and realize cost reduction and efficiency increase.