Description and cause analysis of common problems in asphalt mixing plants

Asphalt mixing stations and equipment must implement secondary leakage protection measures. They can only be used after being plugged in and operated through the circuit breaker before use. During the trial operation, it is necessary to verify that the rotational speed of the mixing drum will be inappropriate.

As a special equipment, standardizing the operating procedures of important production tools of asphalt mixing stations, conducting daily maintenance, regular inspections, eliminating hidden dangers, etc. can effectively ensure the safety and stability of the equipment and prevent equipment from malfunctioning due to misoperation. causing equipment damage. Good maintenance operations can also greatly extend the service life of asphalt mixing plants. Therefore, before daily operation, the asphalt mixing plant must be properly maintained to make the asphalt mixing plant operate better and create wealth.

Emulsion bitumen equipment has stable product quality, closed material transmission, high degree of automation and civilized production, and is easy to standardize management. The double-mill configuration can be used to produce modified emulsified asphalt.
At present, emulsified asphalt equipment is widely used in new technologies and processes for preventive maintenance, such as fog seal, slurry seal, micro-surfacing, cold regeneration, crushed stone seal, cold mix and cold patch materials.
Emulsion bitumen equipment is an emulsion at room temperature formed by dispersing asphalt into the water phase. It is a new material for the use of elements. Compared with traditional hot asphalt, it saves more than 50% of energy and 10%-20% of asphalt, and has little pollution. The biggest feature of emulsified asphalt is that it can be stored at room temperature. It does not need to be heated during spraying and mixing, nor does it need to heat the stone. Therefore, it greatly simplifies the construction, avoids burns and scalds caused by hot asphalt, and avoids the fumigation of asphalt steam when paving high-temperature mixtures. It is very popular among road maintenance workers.

Due to certain restrictions on the current development status and conditions, the profits of the domestic asphalt pavement construction industry are getting lower and lower. Therefore, in the process of using asphalt mixing plants for production, on the one hand, the quality of the products and customer requirements must be ensured. , on the other hand, it is necessary to reduce production costs. Therefore, cost management is very important, and refined management should be implemented in this regard.
First, for device management. Since equipment is the foundation and key of production, in the cost management of asphalt mixing stations, the management of equipment plays an important role in reducing costs. Only by managing the equipment well can the normal working status be ensured, which provides the necessary guarantee for the smooth progress of the project. In fact, in today’s highway projects, equipment costs account for a large part of the cost and profit. The huge profits after the construction of a highway will be greatly affected by the management of materials and equipment.

The quality of asphalt mixture directly determines the quality of asphalt pavement engineering. This article discusses the key points of supervision of ordinary highway asphalt plants in order to better monitor the quality of asphalt mixture.

Judging from the situation of highways in our country, asphalt pavement is the most used, which is one of the reasons why asphalt mixing plants have developed so rapidly. Under the situation of rapid economic development, the quality problems of asphalt pavement are gradually increasing, which puts forward higher and higher requirements for the quality of asphalt. It is understood that the primary factor that affects the quality of asphalt is the ratio of raw materials. This is also covered in the introduction of asphalt mixing stations. You can discuss it together.
In order to obtain high-quality asphalt products, in addition to the asphalt mixing equipment meeting the requirements, selecting the appropriate asphalt mixture gradation type is also a top priority. According to my country’s current regulations, the maximum particle size of the asphalt mixture in the upper layer of the highway should not exceed half of the layer thickness; while the maximum particle size of the aggregate in the middle surface layer of asphalt mixture should not exceed two-thirds of the layer thickness; and the asphalt layer should not exceed half of the layer thickness. The maximum nominal aggregate size of the pavement structural layer mixture should not exceed one-third of the layer thickness.
Based on this analysis, if an asphalt surface layer with a certain thickness is selected according to the above specifications, the particle size of the asphalt mixture aggregates will generally be larger, which will inevitably bring insurmountable construction difficulties to the construction of asphalt concrete pavement. After investigation, testing, analysis, and comparison, it can be seen that the lower layer has a wider choice, so the AG-201 gradation type can be used; while the selection of the upper layer mixture type is more difficult, and it is necessary to achieve a reasonable choice of this mix ratio. , on the one hand, we must examine as many aggregate resources as possible, and on the other hand, we must also consider the model of the mixing equipment.
In order to ensure the quality of the project, strict selection and inspection of engineering materials must be carried out. Therefore, the selection and determination of raw materials should be based on the requirements for pavement structure and use quality, combined with the supply of floor materials, and inspection in accordance with the requirements of relevant test procedures, and then Select the best materials so that all technical indicators of the materials meet the specified technical requirements.

The renovation of the combustion-supporting system of the asphalt mixing plant and the use of DC frequency conversion CNC machining technology are all renovations of the original system. In addition to the above renovation plans, with the existing equipment and personnel, what other measures can be taken in the application to reduce the operating costs of concrete mixing plants?
At present, China has no mandatory national industry standards for heavy residual oil, and the quality of fuel oil varies greatly. Even from the same dealer, the quality difference between batches is very large, and it contains more residues. Therefore, bridge inspection equipment should be installed on the construction site, and professional personnel should inspect various performance parameters of gasoline and diesel to strictly control quality.
When the burner is working, if the flame of the combustion aid is red and the smoke from the ash removal chimney is black, this is the manifestation of poor atomization of gasoline and diesel and insufficient combustion aid. At this time, the following measures should be taken to deal with it: properly adjust the distance between the nozzle and the vortex plate, generally push it inward to a suitable distance, the purpose is to prevent the atomized oil cone sprayed from the nozzle from spraying into the vortex plate; effectively adjust the ratio of gasoline and diesel to gas, so that the gasoline and diesel increase the mass conversion law slowly, or the gas increase the mass conversion law quickly; promptly remove the carbon deposits and coke around the nozzle to prevent the flame from deflecting; heavy residual oil contains more residues, which can easily cause serious damage to the high-pressure oil pump and increase the working pressure, affecting the actual effect of atomization and the shape of the flame, so the high-pressure oil pump must be repaired or replaced in time; install metal filter devices in front of the first and second high-pressure oil pumps, and clean them frequently to prevent the residues in the gasoline and diesel from blocking the nozzle.
The operators should be trained in professional skills on a regular basis to strengthen their job responsibilities and moral education, so that they can establish their respective job responsibilities, understand the importance of their positions, understand the content of their work, and improve their professional level. Skilled operators can properly control the temperature of the asphalt mixing plant mixture to avoid gasoline and diesel waste.
In order to improve the combustion-supporting effect and effectively reduce the operating costs of asphalt mixing stations, Sinoroader Group kindly reminds that the following issues should be noted when using the burner in the asphalt mixing station: To improve the maintenance of the burner, the burner nozzle should be cleaned of charred materials and carbon deposits on the ignition electrode regularly. The nozzle can be disassembled according to the atomization status; the air-oil ratio of the burner is generally not adjusted, and the fuel pump pressure can be adjusted according to the smoke status and the temperature of the asphalt mixture; the sulfur dioxide generated by the combustion of light fuel oil has a strong corrosion to the bag, so the bag should be maintained regularly and the air pressure changes in the bag should be paid close attention to; water deashing will produce more foam, causing the sand settling tank to flow out, so the sand settling tank should be cleaned in time, and a watering design should be carried out to settle the foam; when the steam pressure decreases or the gear oil pump noise increases, the gear oil pump must be replaced.
When the burner is started, the fuel oil circulation system should be completed through the valve, and then the burner control box should be opened to start the burner. If the electronic ignition of the fuel oil fails, you can change the inlet tee and use the diesel engine for ignition. After the ignition is successful for 2 minutes, you can convert it into fuel oil. In this way, even the light fuel oil of lower quality can ensure combustion.

In my country, most of the raw materials used in highway construction are asphalt, so asphalt mixing plants have also developed rapidly. However, under the situation of rapid economic development in my country, the problems of asphalt pavement have gradually increased, so the market requirements for asphalt quality have become higher and higher.
There are many factors that affect the quality of asphalt. In addition to the need for asphalt mixing plant equipment to meet conventional requirements, the ratio of raw materials is also very important. At present, my country’s existing industry specifications indicate that the maximum particle size of the asphalt mixture used on the upper layer of the highway cannot exceed half of the thickness, and the maximum particle size of the aggregate of the middle asphalt mixture cannot exceed two-thirds of the thickness of the layer, and the maximum size of the structural layer cannot exceed one-third of the same layer.

Asphalt mixing plant is a very practical engineering machinery. Especially in the road construction process, it plays an irreplaceable role. Due to its importance, in addition to ensuring its own quality, the use and maintenance of the equipment must be carried out normally. Let’s learn about the daily maintenance requirements of asphalt mixing plants.

1.During the operation of asphalt mixing station equipment, in addition to ensuring that the asphalt mixing station equipment is in good condition, it should also be equipped with a mineral moisture content detector and a finished material tester, and the relevant data should be frequently tested for the operator to adjust the operation in time, so as to keep the equipment in good condition.
2. In addition to affecting production capacity, the moisture content of mineral materials is also the main factor that determines fuel consumption. Additional material sheds should be added.
3. Before operation, all working parts and devices of the asphalt mixing station equipment should be fully checked to see if they are intact and normal. If there is a problem, it must be properly handled before operation, and it is forbidden to operate with illness.

Mechanism to avoid asphalt damage in asphalt mixing plant
1. Asphalt operators should undergo physical examination. Anyone suffering from conjunctivitis, skin disease or allergic reaction to asphalt should not engage in asphalt work.
2. Asphalt operators must apply protective ointment on exposed parts of their skin, and a first aid kit should be provided on the construction site.
3. The factory uniforms and protective equipment of asphalt operators are stored in a centralized manner and are prohibited from being worn home or entering collective dormitories.
4. The transfer of lumpy asphalt should usually be carried out at night and on cloudy days, especially during hot seasons. Small machinery should be used for loading and unloading, and it should not be lifted and transported directly by hand.

Asphalt mixing plant, also known as asphalt concrete mixing plant, is a complete set of equipment for batch production of asphalt concrete. Its efficient and stable operation is of great significance to ensure the quality of the project. It is mainly used in the construction of highways, grade roads, municipal roads, airports, ports and other projects. According to the mixing method, asphalt mixing plant can be divided into forced intermittent type and continuous production type; according to the transportation method, it can be divided into fixed type, semi-fixed type and mobile type.
The working principle of asphalt mixing plant mainly includes steps such as aggregate processing, asphalt processing and mixture mixing. Specifically, aggregates (such as gravel, crushed stone, etc.) are sent to aggregate bins through conveyors or bucket elevators, and then measured by aggregate metering devices, and a certain amount of aggregates are sent to sub-bins. Asphalt is stored in asphalt bins or oil storage tanks, and is measured by asphalt metering devices, and a certain amount of asphalt is sent to asphalt sub-bins. Finally, according to the ratio requirements, different aggregates are taken out from their respective sub-bins and sent to the mixture mixer through conveyors or bucket elevators for mixing.

Asphalt damage avoidance mechanism in asphalt mixing plant
1. Asphalt operators should undergo physical examination. Anyone suffering from conjunctivitis, skin disease or allergic reaction to asphalt should not engage in asphalt work.
2. Asphalt operators must apply protective ointment on exposed parts of their skin, and a first aid kit should be provided on the construction site.
3. The factory uniforms and protective equipment of asphalt operators are stored in a centralized manner and are prohibited from being worn home or entering collective dormitories.
4. The transfer of lumpy asphalt should usually be carried out at night and on cloudy days, especially during hot seasons. Small machinery should be used for loading and unloading, and it should not be lifted and transported directly by hand.

Asphalt mixing plant, also known as asphalt concrete mixing plant, asphalt mixing equipment. Refers to a complete set of equipment used for mass production of asphalt concrete. According to the mixing method, it can be divided into intermittent type and continuous type; according to the transportation method, it can be divided into fixed type, semi-fixed type and mobile type.

Due to its complexity and importance, asphalt mixing plants are more critical in road construction. Modern asphalt mixing stations have five key systems. Do you know what they are?
1. Mixing system of asphalt mixing plant
Mixing equipment is one of the key systems, why? Usually, the productivity of the mixing equipment has a great impact on the next step of construction efficiency. Most asphalt mixing plants use twin-shaft forced mixing. Since the drying drum and burner of the mixing equipment have strong overload capabilities, and in most cases, the moisture content of the mineral materials is less than 5%, this improves the productivity of the mixing equipment. provide conditions. The mixing blades of the mixer have an adjustable assembly angle and are driven by dual mixing shafts and dual motors.

Asphalt mixing equipment is also divided into fixed and mobile types. There are still big differences between the two to a certain extent. Let’s take a look at the design of mobile asphalt mixing equipment. What advantages can bring to the equipment?

During the operation of the asphalt mixing plant, the quality of the mixture is often related to its construction quality. Therefore, we need to improve the quality level of the mixture as much as possible, and the temperature of the mixture is one of the standards for the qualification assessment of the mixture. In other words, if the temperature is too high or too low, the mixture may become waste and cannot meet the needs of use.
Therefore, reasonable control of the temperature of the mixture is one of the basic conditions that must be met for the normal production of the asphalt mixing plant. Among them, the quality of the fuel will affect the temperature of the mixture. For example, if the quality of the fuel is poor, the calorific value is low, and the combustion is incomplete, it will lead to unstable heating, low temperature, and a large amount of residue will be produced after combustion, affecting the quality of the mixture. If the viscosity is large, it will also cause ignition difficulties and the temperature is not easy to control.

The mobile forced asphalt mixing equipment adopts intermittent drying cylinder, double forced mixer, the main machine can be towed, small footprint, short installation cycle, convenient operation and maintenance, good stability, high degree of automation, high degree of standardization, and high quality of finished products, and the technology of continuous improvement. The mobile forced asphalt mixing plant is suitable for high-grade road asphalt paving and maintenance.
1. The combined structure of the drum dryer and the batching machine is installed on a movable bracket for easy movement.
2. The asphalt mixing plant is equipped with a double horizontal shaft to boil the aggregate and ensure uniform mixing.
3. In the densely arranged hanging barrels, the hot aggregate rises vertically. This lifting tool is easy to use and reliable.
4. For accurate weighing of aggregates, asphalt and powder ore, a measuring scale is used, which contains a weighing sensor for electronic measurement.
5. The movement of the power material follows a closed spiral path, which ensures little material loss and provides safe transfer.
6. On the cyclone burner, high-pressure oil is sprayed out and quickly atomized. In the combustion chamber, the material is fed in a spiral manner and automatically ignited by the oil mist, which ensures combustion efficiency. The cylindrical barrel of the burner is separated from the burner head. The furnace cavity can be pushed in and pulled out, which is convenient for replacing the damaged side column bricks inside the burner. The entire burner has a large heat capacity and high thermal strength. This is cost-effectiveness.

Many people think that since both asphalt mixing plants and asphalt mixing plants are equipment for producing asphalt, there should be no difference between them, even if there is, it is only in appearance and volume. However, asphalt mixing plants and asphalt mixing plants are different in even their basic structure and function.
First, let me introduce the basic structure of an asphalt mixing plant, which includes five major components: material supply system, metering system, mixing system, and electrical control system. In comparison, the structure of an asphalt mixing plant is simpler, without so many components, so its operation and maintenance will be simpler.

Asphalt mixing plant is a relatively important complete set of equipment in people’s lives. There are many components of this equipment, such as grading machine, vibrating screen, belt feeder, powder conveyor, elevator and other parts. Plug valve is one of them, so what is the specific role of plug valve in asphalt mixing plant? This article will give a brief introduction.
The plug valve is first of all a closure or plunger-shaped rotary valve. Generally, it is necessary to rotate 90 degrees to make the channel opening on the valve plug the same as that on the valve body, or to split it to play the role of opening or closing. The shape of the plug valve in the asphalt mixing plant is generally cylindrical or conical.

Current highway projects are generally large-investment projects. When carrying out actual project construction, it is very necessary to control the cost of the project. The production cost control and management of asphalt mixing stations in highway projects plays a huge role in controlling the cost of the entire highway project, because the main expenses of highway projects are concentrated on the mixing stations, and almost all the equipment used in highway projects Materials are closely related to the mixing station.

Speaking of asphalt mixing plants, we are not unfamiliar with them. This is a unit equipment specially used for asphalt mixing. In fact, what we really lack understanding of is its gas system. Even the accumulated failures that often occur in the gas system of asphalt mixing plants are not very clear. Facts have proved that only by properly maintaining the various systems of the equipment can efficient production and good benefits be achieved.
The following are four types of gas system failures that often occur in asphalt mixing plants. Let’s analyze the causes of the problems behind the failures one by one.

In recent years, asphalt pavement has dominated highway surfaces. With the rapid development of our country’s national economy, highway traffic volume is increasing, axle loads are increasing rapidly, vehicle speeds are increasing, and there are more and more quality problems occurring on asphalt pavements. Some are damaged after repair, and some have a service life of up to Less than design age. This has put forward increasingly higher requirements for the quality of asphalt pavement, and an important factor affecting the performance of asphalt surface layers is the gradation composition of the mixture. This article discusses the mix design of asphalt mixture.

The asphalt mixing equipment mentioned here may also refer to an asphalt concrete mixing plant. At present, asphalt mixing equipment generally uses a complete set of equipment for mixing. So what are the benefits of using a complete set of equipment?
1. More effective.
In today’s industrial production, a complete set of asphalt mixing equipment can help improve production efficiency and ensure product quality. This is why even in a mixing plant, the equipment used is a complete set of equipment.
2. Ensure quality.
When mixing asphalt, a certain ratio is set. For this type of asphalt liquid used in different occasions, its ratio control has strict requirements. It is necessary to determine its mixing method and mixing time to ensure that the asphalt liquid is consistent with the production site. One of the advantages of a mixing plant is that the quality can be effectively controlled.
3. It can be sampled.
After mixing at the mixing plant, the quality inspector can sample and inspect to ensure that the mixed asphalt liquid meets the use requirements.
In short, asphalt mixing equipment will use a complete set of equipment, mainly to facilitate the later asphalt to meet production needs. Through the mixing plant, the mixing time and feeding sequence can be better controlled, so that the mixed product can meet different use requirements. And after using the archiving equipment, effective spot checks can be carried out, which can better ensure that the quality meets the construction requirements.

When an ordinary asphalt mixing station completes the mixing operation, it will cause great pollution to the surrounding environment. In order to solve this problem, environmentally friendly asphalt mixing equipment came into being. What are the characteristics of this type of equipment?

Safety is the key point for any piece of equipment, and asphalt mixers are of course no exception. What I want to share with you is the knowledge in this area, that is, the safe operation specifications of asphalt mixers. You might as well pay attention to it.

1: The site should be located on higher ground and away from residential areas and densely populated areas.
Because part of the equipment of the mixing station is installed below the ground, in order to avoid continuous rainfall. The equipment will suffer disaster, and the changing aggregate moisture content will affect the concrete quality. Quality accidents are prone to occur. Therefore, during site construction, attention should be paid to the construction of drainage pipelines and sand and gravel quarries. With the rapid development of cities. With the continuous expansion of urban scale, environmental protection requirements will become more and more stringent. Urban roads prohibit gravel vehicles from passing, so concrete mixing plants should be built far away from urban areas.

There is also a reversing valve in the asphalt mixing plant, which generally does not cause problems, so I have not understood its solutions in detail before. But in actual use, we encountered this kind of failure. How should we deal with it?
The failure of the reversing valve of the asphalt mixing station is not complicated, that is, the reversing is not timely, gas leakage, electromagnetic pilot valve failure, etc. The corresponding causes and solutions are of course different. For the reversing valve to not change direction in time, it is generally caused by poor lubrication, the spring is stuck or damaged, oil dirt or impurities get stuck in the sliding part, etc. For this, it is necessary to check the status of the lubricator and the quality of the lubricating oil. Viscosity, if necessary, the lubricant or other parts can be replaced.
After long-term use, the reversing valve is prone to wear of the valve core sealing ring, damage to the valve stem and valve seat, resulting in gas leakage in the valve. At this time, the sealing ring, valve stem and valve seat should be replaced, or the reversing valve should be replaced directly. In order to reduce the failure rate of asphalt mixers, maintenance must be strengthened on a daily basis.