Introduction to the basic operating procedures of asphalt mixing plants

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.

Asphalt mixing plants are large-scale products with high professional and technical requirements, and are composed of multiple systems. Among them, asphalt tanks are also a very critical part. Whether it is manufacturing, debugging or installation, it needs to be operated according to the actual application needs of users.
In addition to the manufacturing, debugging and installation, which need to be operated by installers, the maintenance of asphalt tanks in asphalt mixing plants must also be managed by professionals. At the same time, they must strictly follow all safety rules to operate. Before operation, they must be proficient in the relevant requirements and based on the regulations and safety instructions for storing and handling hot asphalt.

During the asphalt mixing process, we generally use complete sets of asphalt mixing plant equipment to carry out mixing operations. What are the benefits of using complete sets of equipment? Let’s take a look.
1. High efficiency
Complete sets of equipment can help improve production efficiency and ensure production quality.
2. Ensure quality
When mixing asphalt, a ratio will be set. For asphalt liquid used in different occasions, its ratio control has strict requirements. Only by ensuring its mixing method and mixing time can we ensure whether the asphalt liquid meets the production requirements. One of the benefits of using complete sets of equipment in the mixing station is that the quality can be effectively controlled.
3. Can be sampled
After the asphalt mixing plant is mixed, the relevant quality inspection personnel can conduct sample inspections to ensure that the mixed asphalt liquid meets the use requirements.
Using complete sets of equipment in the asphalt mixing plant can more conveniently control the mixing time and the order of feeding, and then effectively sample inspection, so as to ensure that the quality meets the construction requirements.

[1]. Composition of intermittent asphalt mixing plant
The intermittent asphalt mixing plant mainly consists of cold material silo, cold material distribution system, cold material conveying system, combustion and drying system, ventilation and dust removal system, hot material elevator, vibrating screen, hot material silo, powder conveying system and asphalt conveying system. System, metering system, mixing cylinder, control system, finished material transportation and storage system, asphalt heating and insulation system, etc.
2. Discussing the phenomenon of warehouse cascading in asphalt concrete mixing plants
2.1 First, let’s introduce the structure and principle of vibrating screen. The main components include: RetentionRubber, SupportTube, vibrating screen drive system and supporting electrical components
The working principle is introduced as follows: hot aggregate is sent to the vibrating screen through the hot aggregate elevator, and the hot aggregate is vibrated and screened by the vibrating screen. Stones of different specifications enter their corresponding hot aggregate bins through the screen and cannot pass through the geotechnical work. The super-sized particles from the cloth screen enter the overflow bin and are sent out.

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.

The drying and heating system of the asphalt mixing plant can be regarded as an important part of the whole, so in actual work, it treats the material in a countercurrent heating manner, thereby achieving full dehydration of the cold aggregate, and heating it to a certain temperature, thereby providing the necessary conditions for the normal and continuous operation of the asphalt mixing plant.
During the entire heating process of the asphalt mixing plant, the main purpose is to make the performance of the mixture more in line with the requirements of use, and to make the finished material have good paving performance. Under normal circumstances, the heating temperature of the aggregate is about 160℃-180℃.

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.

The actual operation steps of drying drum of asphalt mixing equipment: 1. Pay attention to routine inspection; 2. Proper operation steps; 3. Effective maintenance.
Drying drum is a cylindrical device specially used for heating and drying stones in asphalt mixing equipment. Proper application and maintenance of drying drum can maximize the performance of drying drum, increase its service life and reduce application cost. Let’s take a look at the actual operation steps below.
1. Pay attention to routine inspections
The asphalt mixing equipment drying drum has been tested and inspected before leaving the factory, but it will be subjected to vibration and vibration during transportation to the construction site. A comprehensive inspection should be carried out before use: check whether all anchor bolts are tightened; whether all key pins are properly driven; whether all drive devices are adjusted according to the manufacturer’s instructions; whether all pipe connections are appropriate and whether the three-way joints are reliable; whether the entire equipment is fully lubricated; start the motor and check whether all parts can rotate steadily in the correct rotation direction; whether the pressure gauge can work normally and whether the valve is adjusted to the correct working pressure; whether the burner ignition mechanism is available and whether the gate valve is open.
2. Correct operation steps
After the equipment is started, it is recommended to control the machine manually at the beginning, and then switch to the automatic control mode after achieving the required production volume and pouring temperature. The stone should be dried and have a stable moisture content as much as possible so that the stone can maintain a stable final temperature when passing through the drying drum. If the stones delivered to the drying drum change frequently and the moisture content changes each time, the burner should be adjusted frequently to compensate for these changes.
The stones directly from the crushed stone have a relatively constant moisture content, while the stones from the outdoor storage yard have a higher moisture content, and the moisture content of different piles varies greatly. Therefore, it is best for the stones to come from the same source.

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.

Synchronous gravel sealing in road maintenance can quickly improve road driving performance, repair anti-skid performance, smoothness, etc. It is used in preventive maintenance and is also one of the methods of low-grade road pavement construction. Synchronous gravel seal has the advantages of high strength, rough surface, non-slip, impermeable, good durability, and prevention of water mist when driving on rainy days. The so-called synchronous gravel sealing layer is to use special equipment, namely the synchronous gravel sealing truck and the bonding material (modified asphalt or modified emulsified asphalt) to be spread simultaneously on the road surface, and the single layer of asphalt wear is formed by natural driving or rolling with a road roller. layer, mainly used as asphalt surface layer.

Highways basically use asphalt materials, and asphalt mixing plants can be used to produce a variety of asphalt mixtures. So what are the mixing methods of asphalt mixing plants?
According to the mixing method, it can be divided into: continuous drum type and intermittent forced type. Continuous drum type, that is, the production is produced by continuous and uninterrupted mixing method, and the heating and drying of aggregates and the mixing of mixtures are carried out continuously in the same drum.
Forced intermittent type, that is, the heating and drying of aggregates and the mixing of mixtures are forced to be carried out periodically. The equipment mixes one pot at a time, and each mixing takes 45 to 60 seconds. The output depends on the equipment model.

We know that the first priority in production is to ensure safety. In the process of operating equipment, staff must always pay attention to using the correct operating methods. Regarding the asphalt mixing plant, it is used to produce asphalt mixtures, modified asphalt mixtures, and colored asphalt mixtures to meet the needs of highways, graded highways, municipal roads, airports, etc.

In general, the development of my country’s asphalt mixing plant industry is very rapid. In the ton segment, it quickly occupied most of the market share. And with the advancement of technology, it can basically meet the current development needs. However, the total demand for some large-scale asphalt mixing plants has not increased or decreased. What are the reasons?
If we analyze from multiple angles, it is not difficult to find that these reasons are also some of the problems faced by my country’s current asphalt mixing plantindustry. These problems are summarized as follows:

The asphalt mixing plant is constructed according to a certain process, which can not only ensure the construction quality, but also ensure that the asphalt mixing plant is not damaged. Although the construction details are critical, the key skills of the asphalt mixing plant construction must be mastered.
Before the construction of the asphalt mixing plant, the top surface of the asphalt mixing plant construction range should be removed, and the dry and flat site elevation should be kept to meet the design requirements. If the ground surface is too soft, the foundation should be reinforced to prevent the construction machinery from becoming unstable and to ensure that the pile frame is vertical.

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?

The asphalt mixing plant contains multiple different systems with different functions. The drying system is one of them. Its main function is to heat and dry the materials to reach the temperature required for the process. In order to successfully achieve this goal, the drying system must provide a certain amount of heat.

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.
In order to prevent the asphalt mixer from moving during work, the equipment should be placed in a flat position as much as possible, and at the same time, use square wood to pad the front and rear axles so that the tires are elevated. At the same time, the asphalt mixer must be provided with secondary leakage protection, and it can only be started after the inspection, trial operation and other aspects are qualified.

Asphalt mixing plant is one of the main equipment for producing asphalt concrete. It can mix asphalt, gravel, cement and other materials together in a certain proportion to obtain the products required for highway construction. In order to ensure its operating effect, the asphalt mixer plant also needs to be powered on for trial operation before it is officially put into work.
At the beginning of the test run, first run a single motor, and at the same time check whether the current, steering, insulation and mechanical transmission parts are operating normally. After confirming that each motor and mechanical transmission parts are operating correctly, conduct a joint trial run. During the entire process, it is necessary to conduct patrol inspections of key parts. If any abnormal noise is found, the cause should be identified and eliminated in a timely manner.

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.

Due to the good reliability of asphalt, more and more fields have just begun to use asphalt as raw material for daily production and processing work; such as construction, urban roads, etc. In addition, the processing plant will humanize and manufacture asphalt according to customer requirements, and will use professional technical tools for asphalt mixing work. Compared with the application of old technical equipment, the new asphalt mixing equipment has stronger technicality and efficient operation speed. In addition, the equipment will use an automatic computer operating system to reduce redundant errors and reduce the working time of operators.
In addition, the processing plant will also mix and manufacture asphalt with higher precision asphalt mixing equipment, and only a small amount of raw materials and natural materials will be used for asphalt mixing and manufacturing; and it can reasonably control the quality of goods and improve the quality of goods.
Do you master the whole process of asphalt mixing equipment? The whole working process is a fusion of stone mixing, slag micro powder mixing and asphalt mixing. You can find a lot of detailed information below.

The application of asphalt mixing plants also involves selection issues. In order to give full play to the performance of the equipment, the model of the machine is mainly determined according to the actual situation of the construction site. It sounds relatively simple, but some details still need to be emphasized.
The so-called specific conditions of the construction site first include the size of the site; secondly, the properties, specifications and working dimensions of the enterprise’s supporting equipment. It is necessary to try to do a good job in all aspects to help improve production efficiency and ensure product quality. In the case of intensive network management, the network management function of the asphalt mixing plant must also be taken into account to avoid difficulties in future upgrades.

The drive unit is one of the important components of the asphalt mixing plant, so whether it can be reliably operated must be highly valued to avoid adverse effects on the entire asphalt mixing plant. To ensure that the drive unit in the asphalt mixing plant is indeed complete and reliable, the following maintenance measures are essential.
The first thing to pay attention to is the universal rotating part of the drive unit of the asphalt mixing plant. This part has always been a fault-prone part. In order to reduce the occurrence of faults, grease should be added on time, and the wear should be checked frequently, and repaired and replaced in time. Users should also prepare the universal shaft assembly to avoid affecting the working process of the entire asphalt mixer.

Modified Bitumen

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.

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.

At present, the production efficiency of asphalt mixing plants in my country’s asphalt construction is far lower than the theoretical efficiency at the time of design. The low efficiency of organic waste gas treatment will not only delay the construction process and cause a waste of resources, but also the quality of the construction will not be very good. guarantee. In the construction of asphalt pavement, the main reasons for the low production efficiency of the asphalt plant are insufficient supply of mixture, resulting in loss of continuity of construction, improper equipment parameter settings, excessive overflow and other problems. Effective measures must be taken to deal with these problems, and ultimately improve production efficiency and ensure construction quality.

The development prospects of asphalt mixing plants are very good, and the product competition on the market is also very fierce. When the equipment is used, uneven wear of the supporting wheels and wheel rails often occurs, and sometimes there are some abnormal noises and edge gnawing. The main reason is that after the asphalt mixing station has been working for a period of time, the drying cylinder is exposed to high temperature and friction occurs between the supporting wheel and the wheel rail.
Under the action of drying materials in an asphalt mixing station, the equipment will vibrate violently, which will directly lead to improper adjustment of the gap between the wheel rail and the supporting wheel, or mutual interference between the two. The position is skewed, so the operator needs to add grease to the surface contact positions of the supporting wheel and the calibrating wheel rail after every day’s work.

If asphalt mixing stations want to get approval results as soon as possible and operate normally, they must have corresponding environmental protection conditions. The manufacturer will introduce to you what environmental protection conditions asphalt mixing stations should have.
1. Low energy consumption
This is what asphalt mixing stations must meet. Under the same quantity and quality, the less energy the asphalt mixing station consumes during operation, the more it meets the requirements of environmental protection, such as low consumption of water and electricity resources.
2. Reduce pollution emissions
During the operation of asphalt mixing stations, the adverse effects on the environment should be reduced and pollutants should be better controlled, so that they can be defined as environmentally friendly asphalt mixing stations. At the same time, the requirements of site planning must be met. Whether it is the production area or the conversion area of ??wastewater and waste gas, the corresponding environmental protection requirements must be met.
3. High production efficiency
An environmentally friendly asphalt mixing station must not only reduce energy consumption and reduce the emission of pollutants during the entire production process, but also achieve good production efficiency.

Oscillating screen. It can screen the heated aggregate according to the design. It requires fully enclosed, double oscillating motor replacement (replacing one substance for another (mostly the strong one takes the place of the weak)) eccentric shaft oscillation, each The layer screen is easy to install quickly. The service life of the drying roller and the power part is not less than 6000h. The roller can fully use heat, the material curtain flows evenly, and the inclination is required to be adjustable.