Environmental conditions and functional requirements of asphalt mixing plants

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.

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.

What should I do when the reversing valve in the asphalt mixing plant fails? The editor has a trick:
1. The reversing valve cannot be reversed or the reversing action is slow, which is generally caused by poor lubrication, stuck or damaged springs, oil or impurities stuck in the sliding parts. In this regard, you should first check whether the oil mist is working normally; whether the viscosity of the lubricating oil is appropriate. If necessary, the lubricating oil should be replaced, the sliding part of the reversing valve should be cleaned, or the spring and reversing valve should be replaced.

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.

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.

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.

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.

When inspecting the asphalt mixing plant, it was found that the asphalt in the pipeline solidified because the temperature of the asphalt transportation pipeline did not meet the requirements. Analysis believes that the reasons for this result are that the high-level oil tank of the heat transfer oil is too low, resulting in poor circulation of the heat transfer oil; the second is that the inner tube of the double-layer pipe is eccentric; the third is that the heat transfer oil pipeline is too long; and the fourth is that the heat transfer oil pipeline is not insulated measure.

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.

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:

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.

Colored asphalt pavement is a kind of special pavement material that mixes colored particles into asphalt and then lays on the pavement

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.

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.

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.

At present, the assembly and installation technology of large-scale asphalt concrete mixing equipment in high-grade highway construction is gradually improving. In order to improve work efficiency, it is necessary to analyze the pretreatment agent for the selection and matching of large-scale mixing equipment and auxiliary equipment, and clarify the installation and commissioning of asphalt stations. With the continuous change of highway construction methods, it is necessary to adopt production equipment according to the requirements of the development of the times. Intermittent asphalt mixing equipment is a widely used road construction equipment with the characteristics of simple operation and high work efficiency. Relevant staff are required to master the installation, construction and management methods of mixing equipment.

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 stations, also known as asphalt concrete mixing stations, can produce asphalt mixtures, modified asphalt mixtures, and colored asphalt mixtures, which fully meet the needs of building highways, grade roads, municipal roads, airports, ports, etc. Changmeng Electric Power introduces the safety operating procedures of asphalt mixing plants below:
1. During the operation of the mixing equipment, in addition to ensuring that the 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 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 determining fuel consumption. Additional material sheds should be added.
3. Before operation, all working parts and devices of the mixing equipment should be fully checked to see if they are intact and normal. If there are any problems, they must be properly handled before operation, and it is forbidden to operate with illness.
4. The operation must be carried out strictly in accordance with the procedures and precautions specified in the instruction manual. After normal ignition, the dust collector should be monitored to ensure that the drying drum burns under negative pressure; after production starts, the hot material elevator and agitator should be monitored to see if they are working normally to coordinate the operation of other parts.

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.

There is also a reversing valve in the asphalt mixer, which generally does not cause problems, so I have not understood its solution in detail before. But in actual use, we encountered this kind of failure. How should we deal with it?

Modified Bitumen

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:

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.

Any kind of mechanical equipment must go through precise design, testing and other processes before it can be manufactured, and the same is true for asphalt mixing stations. According to the survey, the following stages are necessary for any asphalt mixing plant.
First of all, the main technical parameters of the product to be designed must be determined according to market needs, so construction market research, data analysis and other links are indispensable. Secondly, the ideal working principle and the plan to realize this principle will be determined through innovative conception and optimization screening. , a schematic diagram of the overall design scheme should also be given.

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.

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.

Judging from the current situation of domestic highway construction, asphalt mixing stations will also achieve great development for a long time to come. This is also a result of rapid economic development. However, we have found that more and more quality problems occur when constructing asphalt pavements in modern times. Therefore, we have to put forward more stringent requirements for the quality of asphalt.

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.

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.