Asphalt batch mixing plant is the core industrial equipment for producing high quality hot mix asphalt mixture in road engineering, municipal infrastructure, airport pavement and other projects.Equipment in high temperature, high dust, strong friction, material impact for a long time of bad working condition, all kinds of vulnerable parts wear and tear, accessories selection, procurement, professional maintenance, directly determine the equipment availability, mixture finished product quality, production energy consumption and construction cost.Many mixing station operation and maintenance and procurement personnel often fall into the "low price for high frequency replacement, high price without real income, accessories do not match the cause of failure."
This paper will systematically explain the equipment principle, core value of accessories selection, classification of core accessories, wear and tear law of vulnerable parts, professional purchase standard, choice of accessories between original factory and auxiliary factory, common mistakes in procurement and long-term maintenance skills of asphalt batch mixing station, comprehensively answer the core problems of how to select, maintain and save money for accessories of asphalt mixing station, and provide standardized and landing accessories for engineering practitioners. Management scheme.
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Asphalt mixing station, also known as asphalt mixing station and hot mix asphalt production equipment, is a complete set of industrial equipment specially used for industrial production of hot mix asphalt mixture (HMA, commonly known as asphalt concrete and asphalt mixture). The mixture produced is widely used in various infrastructure projects such as expressway, municipal road, parking lot, airport runway, park pavement, etc.The core working principle of the equipment is to mix macadam, gravel and sandstone aggregates with different particle sizes with liquid asphalt binder, mineral powder filler and various modified additives according to standardized process proportioning, dry at high temperature and fully mix to form asphalt mixture with uniform performance, strong cohesive force and conforming to construction standards.
According to the difference of production mode and structure, the mainstream asphalt mixing station in the industry is divided into two core types to meet the production demands of different projects: the first is intermittent mixing station, which is also the mainstream type selection of high-standard projects at present. It adopts the production mode of independent screening, weighing and mixing in batches, with extremely high proportioning accuracy, which can flexibly switch various mixture formulas and adapt to high road grade. Engineering projects with changeable formulas and strict quality requirements; The second is the drum continuous mixing station, which integrates the drying and mixing processes in the same rotating drum for continuous operation. The equipment structure is simplified, and the hourly capacity is higher. It is suitable for long-term large-scale production of large-scale and single-formula mixtures.
Most mixing station operation has cognitive misunderstanding, only regard accessories as fault replacement consumables, and ignore the core role of quality, fitness and material on the whole machine.High-quality special accessories are the key to ensure stable operation of equipment, control mixture quality, control operating costs and implement safety, environmental protection and compliance.The selection of inferior, non-standard and mismatched accessories may save the procurement cost in the short term, but may easily cause problems such as sudden shutdown of equipment, unqualified mixture, secondary damage of main engine, environmental protection penalty, etc. in the long term, which will greatly increase the comprehensive operation cost.
Selecting the right parts can effectively avoid production loss and quality risks.High-quality accessories wear resistant and durable, low failure rate, can put an end to mixing, dust removal, transportation and other core components failure caused by downtime, avoid delays, labor and energy waste.At the same time, it can stabilize the process precision of the whole process of drying, screening, mixing and metering, solve the problems of mixture segregation, unbalanced proportioning, uneven temperature and the like, avoid road surface cracking, rutting, peeling and other construction diseases from the source, and ensure the engineering pavement quality.
High-quality accessories can also realize long-term cost reduction and standardized operation and maintenance.The service life of upgraded material accessories is longer, which can reduce the replacement frequency, labor cost and equipment maintenance expenditure, and reduce the whole life cycle cost of equipment.Its compliance and adaptation characteristics can not only avoid potential safety hazards and environmental protection exceeding risks, protect the original value of the host, retain the warranty rights and interests of the original equipment factory, but also help the operation and maintenance personnel to predict the loss cycle, plan the maintenance inventory, and realize refined and normalized equipment management.
Asphalt batch mixing station has complex process and various systems, from raw material conveying, drying and heating, screening and metering, mixing and molding to dust removal, environmental protection and intelligent control, each system is equipped with exclusive core accessories.The working conditions, loss speeds and core functions of different accessories are greatly different. Accurate differentiation of accessory types and functions is the basis for scientific type selection and efficient maintenance.Combined with the equipment operation structure and loss characteristics, mixing station core parts can be divided into ten categories, covering the whole production process.
Mixing tank is the core unit of mixture molding, and also the most severe wear area of the whole equipment. The accessories bear the impact of high-temperature aggregate, strong friction of sandstone and asphalt corrosion for a long time, with the fastest loss speed.The core accessories include mixing arm, mixing blade, alloy wear-resistant end, cylinder liner wear-resistant plate, shaft end sealing sleeve, discharge gate assembly, etc.The mixing arm is responsible for supporting and driving, the blades directly complete the mixing and wrapping of materials, the lining plate protects the mixing cylinder body from abrasion, and the shaft end is sealed to prevent asphalt leakage and dust intrusion.Wear of the series of accessories will directly lead to uneven mixing, mixture segregation, leakage and other problems. It is generally recommended in the industry to keep 2-3 sets of spare parts in stock to ensure timely replacement.
Drying drum is the core equipment for aggregate heating and drying, which is under the working conditions of high temperature and continuous scouring of materials for a long time. The core accessories include drum lifting plate, cylinder wear-resistant lining plate, feeding and discharging sealing elements, riding wheels, supporting tires, thrust rollers, bearing components, etc.Among them, the lifting plate is the core functional part, which forms a uniform material curtain by continuously rotating to raise the aggregate, maximizes the contact with high-temperature flue gas and ensures the drying efficiency; the sealing element eliminates air leakage and heat leakage, and reduces energy consumption; the riding wheel and bearing ensure the smooth operation of the roller.The deformation and wear loss of the lifting plate will directly lead to the decrease of drying efficiency, the sharp rise of fuel consumption and the uneven temperature of aggregate.
Only batch mixing station is equipped with, the core function is grading screening high temperature aggregate, aggregate grading standard.Core accessories for multi-layer wear-resistant screen, screen tension clamp, damping spring, excitation motor, vibrator, etc.Screen is the core parts, long-term impact by high temperature aggregate, high-frequency vibration, easy to appear broken wires, holes, relaxation and other problems, once damaged will lead to coarse and fine aggregate mixing, grading imbalance, directly affect the pavement construction quality.Screen tension and integrity are the core guarantee of screening accuracy.
Responsible for the whole process of material transfer, to ensure the continuity of production, the core parts include belt conveyor belt, roller, roller, bucket elevator chain, hopper, sprocket, drive motor, reducer, bearing, etc.During the operation of the equipment, the accessories continuously bear the friction of materials, high temperature baking and heavy load stretching, and the chain, sprocket and adhesive tape wear at the fastest speed. Once the accessories fail, the material conveying will be directly interrupted, resulting in the shutdown of the whole machine.
The core components that determine the mixture proportioning accuracy directly affect the quality stability of finished products. The core components include aggregate weighing sensor, asphalt weighing module, mineral powder weighing component, pneumatic cylinder, discharge valve, induction sensor, signal amplifier, etc.Weighing sensor is affected by vibration, high temperature and dust for a long time, which is easy to cause numerical drift and precision deviation, resulting in unbalanced proportion of asphalt, aggregate and mineral powder, causing diseases such as pavement flashing, looseness and cracking, etc., requiring regular calibration and timely replacement of faulty accessories.
Responsible for asphalt storage, heating, transportation and metering, adapt to high temperature corrosion conditions, the core parts include asphalt pump, mechanical seals, high temperature resistant valve, sealing gasket, O-ring, thermocouple temperature probe, heat transfer oil heating components, etc.Asphalt has strong corrosivity and high viscosity. Long-term high temperature operation will lead to aging of sealing elements, pipeline blockage, temperature measurement failure, poor asphalt pumping, excessive temperature, leakage and smoke, etc.
Ensure equipment environmental protection standards, the core system of dust recycling resources, the core parts are high temperature dust removal filter bag, bag cage, pulse injection valve, electromagnetic diaphragm valve, rotary discharge valve, dust removal pipe, spiral ash conveyor, etc.The filter bag is the core wearing part. It is easy to be blocked, damaged and aged due to long-term high temperature flue gas, dust scouring and pulse airflow impact, which will lead to abnormal dust removal pressure difference, capacity reduction and excessive dust leakage.
Responsible for raw material storage, quantitative blanking and high temperature aggregate temporary, core accessories include cold bin vibration motor, frequency conversion feeder, discharge gate, hot bin material level sensor, pneumatic control components, sealing gasket, etc.The main function is to ensure uniform blanking of raw materials without blocking, accurately control material reserves and blanking amount, and stabilize production rhythm from the source. combustion system accessory of combustion engine
The heat source core of the equipment determines the drying efficiency and energy consumption level, and the core accessories include ignition electrode, fuel nozzle, flame sensor, photoelectric tube, solenoid valve, fuel filter element, etc.Long-term high temperature operation is easy to appear carbon deposition, clogging, aging, cause ignition failure, insufficient combustion, flame instability, black smoke and other problems, directly affect the aggregate drying effect and fuel consumption.
The "brain" of equipment operation, the core accessories include PLC control cabinet, relay, contactor, fuse, variable frequency drive, various temperature and pressure sensors, circuit components, etc., responsible for the whole process monitoring, automatic control, data recording, accessories failure will lead to equipment alarm, shutdown, parameter disorder, production out of control.
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Based on the standard production conditions, conventional aggregate materials and daily production time, combined with the actual loss data of the industry, the wear rate and service life of various accessories of asphalt batch mixing station are significantly different.Accurately grasp the list of parts with rapid loss and loss incentives, and formulate targeted stock preparation, maintenance and upgrade plans to avoid the risk of downtime in advance.The following is the industry recognized high loss parts ranking and detailed parameters.
First place: mixing blade, mixing end, standard material service life of only 6-18 months.As the core component in direct contact with high-temperature and high-hardness aggregate and asphalt, the continuous high-speed friction, material impact and wear strength are the highest.The service life can be increased to more than 24-36 months after upgrading the materials of high chromium alloy and tungsten carbide.
Second place: mixing cylinder wear-resistant lining board, standard material service life of 12-24 months.It is the core component for the protection of the mixing cylinder, which can withstand the sliding friction and extrusion wear of materials for a long time. Excessive wear will cause damage to the cylinder body. The service life of the high-chromium material can reach 36-48 months after upgrading.
Third place: drying drum lifting plate, the standard material service life of 12-24 months.Long-term in high temperature environment to undertake, throwing aggregate, thermal deformation, material erosion double loss, easy to bend, damage, fall off, Alloy-K alloy, tungsten carbide upgrade material life can reach 36-60 months.
4th place: vibrating screen, the service life of standard material is 6-18 months, which is greatly affected by the hardness of aggregate.Continuous impact and high-frequency vibration of high-temperature aggregate may easily lead to broken wires and holes. The loss rate of granite and other high-hardness aggregates will be doubled under the working condition, so it shall be inspected and replaced in time.
Fifth place: dust removal filter bag, the standard material service life of 12-24 months, wet, high dust conditions, shorter life.High temperature flue gas aging, dust scouring and pulse repeated blowing are the main reasons for loss. PTFE membrane and high temperature resistant synthetic material can greatly prolong service life.
Sixth place: conveyor chain, sprocket, belt, the standard service life of 12-24 months.Continuous material conveying friction, high temperature tension, heavy load operation, sprocket wear speed is generally faster than the chain, is the high frequency fault point of conveying system.
7th place: Hoist hopper and chain, standard service life 12-24 months.High temperature aggregate impact, friction loss is given priority to, tungsten carbide lip upgrade hopper can effectively reduce wear and tear.
Eighth place: burner nozzle, ignition electrode, service life of several months to 1 year.Long-term high-temperature carbon deposition, fuel impurity blockage, easy to appear ignition failure, uneven combustion, regular cleaning can effectively prolong the service life.
The purchase of asphalt mixing plant accessories is not a simple comparison of price. In order to give consideration to quality, stability and long-term cost performance, it is necessary to comprehensively screen the eight core dimensions such as material, adaptability, working condition, cost and supplier strength, so as to avoid purchasing errors such as low price and inferior quality, inconsistent model and material mismatch, so as to realize accurate selection and long-term durability.
The material of accessories directly determines the service life of accessories and the operation stability of equipment. It is necessary to match the exclusive wear-resistant, high-temperature resistant and corrosion-resistant materials according to different system working conditions. When purchasing, it is necessary to verify the material and hardness test report to eliminate inferior materials such as ordinary carbon steel.Precision selection of core accessories: Stirring blades and lining plates are preferably made of 12%-26% high chromium cast iron (HRC55 -62) or tungsten carbide alloy, which are impact resistant and wear resistant; drying lifting plates are made of Alloy-K alloy steel and high chromium wear resistant steel, which are resistant to high temperature and thermal deformation; dust removal filter bags are made of Nomex and PPS high temperature resistant fibers, and PTFE coating is used for anti-adhesion under high viscosity conditions; sealing gaskets are made of high temperature and oil resistant composite materials, which are suitable for asphalt corrosion and high temperature aging environment; screens are made of high tensile alloy steel wires, which are resistant to earthquake and breakage.
Mixing plant accessories precision requirements are extremely high, slight size deviation will cause assembly failure, abnormal operation.When purchasing, it must strictly match the equipment brand, complete machine model, original parts number, and eliminate general non-standard parts.The key size tolerance of stirring arm, lifting plate, special-shaped lining plate, weighing component and other key accessories shall be controlled within ±0.5mm to ensure assembly fit, no dislocation and no looseness.size matching accessories can avoid equipment vibration, leakage, sealing is not tight, secondary wear and other problems, to ensure the original equipment operating accuracy.
Parts selection does not need to be one-size-fits-all, but needs to be differentiated according to the functional attributes of accessories: combustion machine, PLC control system, weighing sensor, precision valve and other safety and precision core components, priority should be given to original OEM accessories, adaptability 100%, stable performance, perfect warranty, avoiding precision deviation and safety risks; Mixing blades, lifting plates, screens, filter bags, chains and other pure wear parts, can choose regular high-end accessories, high-quality accessories can provide upgraded wear-resistant materials, service life is better than the original standard parts, and faster supply, higher cost performance.
Purchasing accessories should abandon the misunderstanding of "only looking at the unit price" and focus on accounting for the whole life cycle cost.Low-priced accessories have low procurement costs, but their service life is short, frequent replacement, superimposed manual replacement costs, downtime losses, equipment secondary maintenance costs, and comprehensive costs are extremely high.Although the unit price of high-end wear-resistant accessories is 40%-100%, the service life can be increased by 2-3 times, the replacement frequency and hidden loss are greatly reduced, the cost of single ton mixture is lower, and the long-term economic benefit is more significant.
High quality suppliers are important guarantee of parts quality, reliable parts suppliers need to deeply cultivate asphalt mixing equipment industry for more than 5 years, have rich supporting cases of the same type of equipment, have ISO9001 quality system certification, can provide complete material test sheet, hardness test report, service life measured data.At the same time, it needs to have sufficient stock inventory, rapid supply capacity, equipped with professional technical team to provide installation guidance, fault answering service, perfect after-sales warranty system, free replacement service for defective products, and guarantee procurement rights.
There is no universal optimal fitting, only the right fitting for the working condition.High hardness aggregate, high daily production capacity, continuous production of high strength conditions, must choose upgraded high wear-resistant accessories; wet, low temperature conditions should give priority to the selection of anti-condensation, corrosion resistant accessories; conventional light load conditions can choose standard wear-resistant accessories.According to its own aggregate characteristics, production time, climate conditions match the grade of accessories, can maximize the performance of accessories, avoid excessive procurement or accessories wear too fast.
Regular accessories shall have clear warranty clauses and perfect quality control system. The production process shall go through multiple quality inspection procedures such as hardness test, size calibration, nondestructive inspection, etc., and the material shall be traceable.When purchasing, specify the warranty period of accessories and the replacement policy for faults, avoid three-no products, and guarantee the quality rights and interests during the use of accessories.
Modular, quick-fit design accessories, such as bolt-type lifting plates, modular liners, quick-change blades, can greatly shorten the replacement time, reduce downtime maintenance time.At the same time, confirm the installation drawings and technical guidance of accessories to facilitate daily maintenance, replacement and debugging in the later period, and reduce the difficulty of operation and maintenance.
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In the procurement of asphalt mixing plant accessories, the selection of original OEM accessories and auxiliary factory accessories is the core problem of operation and maintenance procurement personnel.Each of the two types of accessories has its own advantages and disadvantages, but there is no absolute good or bad. Only when the adaptation scenarios are different, combined with the targeted selection of accessory functions, working conditions, budget and risk level, can the optimal balance between quality and cost performance be achieved.
The original accessories are the original supporting products of the equipment manufacturer. They are produced in strict accordance with the original design parameters of the equipment. The size, precision and material completely match the equipment model. The adaptation degree is 100%. The operation stability is extremely strong. There are no problems such as assembly deviation and performance mismatch.The core advantage is stable quality, extremely low failure rate, can guarantee the original warranty rights of equipment, supporting professional technology after-sales; short board is high purchase unit price, long supply cycle, some niche accessories need customized production, poor emergency supply capacity, and conventional wear-resistant accessories material is ordinary, service life has no advantage.Original accessories are most suitable for combustion machines, precision sensors, PLC control systems, weighing modules, core valves and other precision, safety, warranty related critical system accessories, as well as equipment still within the warranty period.
The regular high-end auxiliary factory accessories are produced by professional wear parts manufacturers. They are optimized and upgraded for the working conditions of wearing parts of mixing station. On the basis of standard size completely matching the original factory, high-end materials such as high chromium alloy, tungsten carbide and PTFE coating can be upgraded. The wear resistance, high temperature resistance and corrosion resistance far exceed the original standard parts, and the service life is longer.At the same time, the accessory purchase price of the auxiliary factory is lower, the stock is sufficient, the supply speed is fast, and the emergency adaptability is strong; the short board is a small group of precision accessories with uneven precision, and the inferior accessory factory parts have problems such as size deviation, false material standard, no warranty, etc.High-end accessories are most suitable for mixing blades, lining plates, lifting plates, screens, filter bags, chains, seals and other high-frequency loss accessories.
Combined with practical operation experience in the industry, the optimal selection scheme is "the original factory for precision core parts, and the high-end auxiliary factory for high-frequency wear-resistant parts".Safe and precise, affecting the core components of the whole machine control system and quality assurance system, giving priority to the original zero-risk guarantee; high-frequency wear, upgradeable and optimized consumables accessories, selecting high-end auxiliary factory accessories with complete qualifications and reliable quality, taking into account stability, cost performance and service life, achieving the dual goal of reducing cost and improving quality.
Most of the mixing plant accessories wear too fast, frequent failures, high cost problems, are due to procurement and selection errors.In combination with the common problems in the industry, sort out the top ten high-frequency procurement mistakes, and match the avoidance scheme that can be landed to help the operation and maintenance procurement personnel accurately avoid the pit.
The most common purchasing misunderstanding is to simply compare the purchase unit price, give priority to the lowest-priced accessories, and ignore the material quality and service life.Low-priced inferior accessories have poor wear resistance, and their service life is only 1/3 of that of high-quality accessories. The labor cost of frequent replacement, downtime loss, and secondary maintenance cost of equipment are much higher than the price difference of accessories.
Blindly purchasing universal accessories without checking equipment model and original accessory number, resulting in mismatch of accessory size, installation point and tolerance.After assembly, it is easy to loose, vibrate, leak material, loose seal and uneven force, which accelerates equipment wear.
When purchasing, it does not pay attention to core parameters such as alloy content, hardness and temperature resistance grade, and cannot distinguish between ordinary materials and wear-resistant upgraded materials, resulting in parts that cannot adapt to high temperature and strong wear conditions, and aging and damage occur in a short period of time.
Select a small number of low-cost sub-factory suppliers without qualification, no after-sales service and no test report. The accessory material is false, the precision is not up to standard, the quality is unstable, the failure rate is extremely high and there is no after-sales guarantee. Neglecting working condition differences, unifying standard selection
Regardless of aggregate hardness, production capacity, production time, all use the same standard parts, high load conditions under the rapid wear of standard parts, light load conditions excessive procurement waste costs.
The core wearing parts are not reserved, and the emergency procurement is only after the parts fail, resulting in long-term downtime of the equipment, delay in the construction period and heavy losses.
When replacing accessories, only replace parts with partial wear. The old and new accessories are mixed, and the hardness and size are inconsistent, resulting in uneven stress on the equipment and accelerating the two-way wear of the old and new accessories.
When purchasing, the warranty clause is not confirmed, the material report and purchase certificate are not kept, the rights cannot be protected after the quality problems occur in the accessories, and the non-standard accessories may lead to the failure of the original warranty of the equipment.
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The stable and efficient operation of asphalt batch mixing plant lies in the scientific selection of accessories, standardized maintenance and fine management.As industrial equipment under high temperature and high wear conditions, the quality, adaptability and service life of various accessories of mixing plant directly determine the production quality of mixture, equipment start-up rate, project duration and comprehensive operating cost.Operation and maintenance procurement personnel shall abandon the traditional misunderstanding of "emphasizing price, light quality, heavy replacement and light maintenance", clearly grasp the equipment principle of mixing plant, core parts function and wearing parts loss law, combine their own production conditions, distinguish the matching scenarios of original and auxiliary parts, and take material, precision, full life cycle cost and supplier strength as the core selection criteria to avoid procurement misunderstanding.
