Introduction to the basic operating procedures of asphalt mixing plants

The quality of the asphalt mixing plant will be a key factor affecting the quality of the project. After reviewing relevant materials related to the production and construction of asphalt concrete, we summarized some cases of failures in asphalt concrete mixing stations during construction and analyzed the reasons.
1. Unstable output and low production efficiency of asphalt mixing plants
(1) Improper proportioning. The mix ratio of asphalt concrete is divided into target mix ratio and production mix ratio. Among them, the target mix ratio controls the cold material transportation ratio of sand and gravel materials, and the production mix ratio is the mixing ratio of various types of sand and stone materials in the finished asphalt concrete materials specified in the design. The production mix ratio is determined by the laboratory, which directly determines the off-site grading standard of the finished asphalt concrete. The target mix ratio is set to further ensure the production mix ratio, and can be adjusted appropriately during production according to the actual situation. When the target mix ratio or the production mix ratio is not appropriate, the stones stored in each measurement of the asphalt mixing station will be disproportionate, with some overflowing and some other materials, unable to be weighed in time, and the mixing cylinder will be idling, resulting in reduced output.

Asphalt mixing plants are highly professional equipment with complex systems. It is inevitable that some failures will occur during use. So, what are the common hardware failures of asphalt mixing plants? Do you know?
(I) Because its system is relatively complex, when different components have problems, the problems caused may be different. If during the operation, it is found that the material addition of each silo is inaccurate, this problem may be due to the failure of the sensor of the asphalt mixing plant. At this time, the machine should be stopped for inspection and replaced with a new sensor if necessary. It may also be caused by the jamming of the scale bar. At this time, foreign objects should be removed in time.

In today’s road construction, the use of a large number of road construction machinery represents the entry into the era of highway mechanization. For users, the goal is to use road construction machinery reasonably and tap its potential as much as possible. However, road construction machinery requires various accessories to work together. Now let’s take the asphalt mixing plant as an example to see what commonly used accessories and equipment are available.
Asphalt mixing plant equipment is a relatively complex system, which includes many equipment, mainly nine parts, namely: bag dust removal, finished material temporary storage warehouse, grading machine, fast heating asphalt tank, asphalt barrel removal machine, asphalt recycled material crushing and screening system, coal block crusher, coal mill and dust removal equipment, etc.

1. Causes of overflow
The main causes of spillage are:
1) Mixing materials in cold silo. Cold material warehouses generally have 5 or 4 warehouses. Each warehouse is required to contain pellets of a certain specification. If cold materials of different specifications are mixed or mistakenly loaded during the loading process, it will cause certain occurrences in a certain period of time. The shortage of pellets of one specification and the overflow of pellets of another specification can easily destroy the supply balance between hot and cold silos.

Certain failures cannot be avoided during the use of the asphalt mixing plant. For example, a malfunction of the cold material feeding device may cause the asphalt mixing plant to shut down. This may be due to a malfunction in the asphalt mixing plant or due to gravel or foreign matter being trapped under the cold material belt. If it is stuck, if it is a circuit failure, first check whether the motor control inverter of the asphalt mixing station is faulty and whether the line is connected or open.

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?

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.

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.

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.

With the strengthening of the trend of environmental protection and energy conservation, the environmental protection of asphalt mixing plants has gradually become the mainstream form of mixing plant development. What kind of equipment can be called an environmentally friendly asphalt mixing plant? What are the basic conditions that must be met?
First of all, as an environmentally friendly asphalt mixing plant, it must meet the requirement of using less energy consumption during use. That is to say, under the conditions of the same quantity and quality, less energy is consumed during the operation process, including various resources such as water and electricity.
Secondly, environmentally friendly asphalt mixing plants not only require less energy consumption, but also must achieve higher production efficiency, while also reducing carbon emissions in the entire production process, so as to meet the proposed low-carbon production requirements.

Asphalt is commonly used in our modern urban life, especially in the process of urban highway construction. As an important road surface paving material, the demand for its use is relatively high. Only by using better relevant material performance characteristics can the overall effect be well helped.
Asphalt mixing plants are equipment products that need to be involved in the production and use of such products. With its own excellent performance, it has been better expanded in the promotion of the existing market use scope. The coordination of external use factors is also a key part, and the relationship between various factors must be handled well.

The core of the asphalt mixing plant is its electronic control system. If it has problems, it will cause a lot of trouble to use. However, in actual use, the electronic control system in the asphalt mixing plant will inevitably encounter some problems and failures. How to solve it at this time?
If only the instrument display of the electronic control system of the asphalt mixing plant is inaccurate, it means that the weighing system may be affected by external forces; or the drift error of the sensor causes the weighing zero position or weighing interval to change; it may also be caused by sensor damage.

At present, most asphalt mixing plants have different degrees of energy loss in use, and these losses have brought us serious waste. How to reduce energy consumption in these aspects and achieve efficient production?
First of all, we must first summarize which aspects have energy loss, and then we can find reasonable solutions based on these problems. Through research, it is found that there are four problems in the use of asphalt mixing plants and the production of asphalt mixtures. The content and measures are as follows:
The first aspect is the management of the pile. We can reduce the energy consumption of the asphalt mixing plant through 3 specific methods: 1. Appropriately reduce the stacking height of the pile; 2. Build an inclined pile site with a good drainage structure; 3. Build a waterproof canopy.

The basic working principle of the green asphalt mixing plants can be roughly summarized in the following ways:
To put it simply, an asphalt plant is actually a set of equipment that can mix several materials according to a predetermined ratio to form a relatively uniform mixture. It is currently widely used and is very important for the construction of different projects. Its performance Various aspects also have a great impact on the engineering quality of asphalt pavement.
Asphalt mixing plant equipment is usually divided into two structures. The intermittent type is relatively more complex in structure and process. The aggregates need to be screened twice and then measured in batches. The batching accuracy is higher. , the mixing quality is good and can meet different construction requirements. The continuous type has a slightly lower accuracy due to its simple structure and simplified operating procedures.

The HMA-B series forced asphalt mixing plant can produce reliable quality asphalt in various proportions. The product technology is mature, the operation is stable, the specifications are complete, the efficiency is high, the output is large, and the finished asphalt quality is good. It is suitable for various sizes and This type of road construction project has more obvious advantages in larger-scale road construction projects and high-grade highway construction projects.

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.

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.

In the 21st century, with the booming development of modern engineering construction, complex integrated supporting equipment has been invested in large quantities. Its complex process and more independent operating components have relatively high requirements for the performance of its equipment control system. The application of PLC in asphalt mixing station realizes the control of the entire process of asphalt mixing station, which facilitates the construction of modern engineering construction. Therefore, this article discusses and analyzes the application of PLC in asphalt mixing station, which has certain economic value and practical significance.

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?

With the strengthening of the trend of environmental protection and energy conservation, the environmental protection of asphalt mixing plants has gradually become the mainstream form of mixing plant development. What kind of equipment can be called an environmentally friendly asphalt mixing plant? What are the basic conditions that must be met?
First of all, as an environmentally friendly asphalt mixing plant, it must meet the requirement of using less energy consumption during use. That is to say, under the conditions of the same quantity and quality, less energy is consumed during the operation process, including various resources such as water and electricity.
Secondly, environmentally friendly asphalt mixing plants not only require less energy consumption, but also must achieve higher production efficiency, while also reducing carbon emissions in the entire production process, so as to meet the proposed low-carbon production requirements

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.

When we operate the asphalt mixing station, we should heat the equipment half an hour in advance, and the clear tank should be heated for at least two hours; and manually operate each part of the equipment to ensure that it is in good operation. status; it is also necessary to conduct relevant inspections on the valves and manually collect and return oil to ensure that the equipment can operate normally.
Several requirements for safe operation of asphalt mixing plants:

Due to raw materials or usage, asphalt mixing plants will be subject to a certain degree of wear or other failures during daily use. If they are not controlled or repaired in time, the problem will be further exacerbated. For asphalt mixing plants, what are the ways to prevent wear and failure?
If the asphalt mixing plant is not treated in time after being worn, it may corrode once it is in contact with air, rainwater, etc. for a long time. If the parts of the asphalt mixing plant are severely corroded, the service life and normal operation of the entire equipment will be affected.

Asphalt mixing plants bring a lot of convenience. You should understand what asphalt is. Asphalt is a very viscous liquid with a black surface that dissolves carbon disulfide. They generally exist as asphalt and smoke tar. Asphalt appeared early in social life.

The materials used in asphalt mixtures contain a lot of dust. When the equipment is operating, if the dust enters the atmosphere, it will cause pollution. Therefore, dust removal equipment must be installed, and now bag dust removal is the main method. Safety is a common sense issue. There are well-established standard safety rules.
Do not clean, oil or adjust any mechanical equipment that is not specifically explained during operation; turn off the power and lock it before inspection or repair activities to prepare for accidents. Because each situation has its own particularity. Therefore, be vigilant about safety damage issues, incorrect operation issues and other deficiencies. All of them may lead to accidents, personal injuries, reduced production efficiency, and more importantly, loss of life. Careful and early prevention is the best way to avoid accidents.
Careful and correct maintenance can make the equipment work more efficiently and control it within a certain level of pollution; the maintenance of each component should be carried out according to its operating standards; maintenance plans and safe operation procedures should be formulated according to the inspection and repair conditions that must be carried out.
Take out a work log to record all inspection and repair conditions, list the analysis of each inspection of each component and the description of the repair content or the date of the repair; the second step is to give the inspection cycle for each component, which should be determined according to the service life and wear condition of each component.

Natural gas is a colorless, odorless, flammable and explosive gas, the main component of which is methane, which accounts for about 98% of natural gas. The density of natural gas is lower than that of air and it is difficult to liquefy. Natural gas is not only a clean green energy for civil, commercial and industrial use, but also a raw gas for chemical industry. The theoretical ignition value of natural gas is 540 degrees, the combustion temperature is 1970 degrees, the calorific value is 40MJ/m3, and the explosion limit is 5%-15%. CNG refers to natural gas that has been compressed to 20-25MP and stored in high-pressure gas tank trucks, and then transported to various gas transmission points to supply gas to residential users, commercial users and industrial users. In order to ensure the normal operation and safety of the asphalt mixing station and our pressure regulating station, our company has specially formulated the following safety protection measures.

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.

Certain failures cannot be avoided during the use of the asphalt mixing plant. For example, a malfunction of the cold material feeding device may cause the asphalt mixing plant to shut down. This may be due to a malfunction in the asphalt mixing plant or due to gravel or foreign matter being trapped under the cold material belt.

Asphalt mixing plant equipment is mainly composed of batching system, drying system, ignition system, hot material lifting, vibrating screen, hot material storage bin, weighing mixing system, asphalt supply system, granular material supply system, dust removal system, finished product hopper and automatic control system.
Components:
⑴ Grading machine
⑵ Vibrating screen
⑶ Belt vibrating feeder
⑷ Granular material belt conveyor
⑸ Drying mixing drum;
⑹ Coal powder burner
⑺ Dust removal equipment
⑻ Bucket elevator
⑼ Finished product hopper
⑽ Asphalt supply system;
⑾ Distribution station
⑿ Automatic control system.

In the construction industry, the installation and application of asphalt mixing plants can often be seen. This kind of equipment can complete the processing process of limestone and other powder products. The equipment has a reasonable structure and high working efficiency. It can save more costs for manufacturers during the production of asphalt raw materials. Therefore, the construction and other industries now attach great importance to the application of this equipment. During the production and processing of the equipment, the staff also need to pay attention to several operating skills to ensure that the equipment can operate stably and provide more benefits for production work.