METERING SYSTEM

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.

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 mixing station 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.

Asphalt mixing plant is also called asphalt mixture mixing equipment, which is mainly used to produce asphalt mixtures of various specifications. It is an important equipment in projects such as road construction, highway maintenance and airport runway construction. The main components of an asphalt mixing plant include cold material supply system, drying drum, screening system, weighing system, agitator, finished product silo and control system.
The workflow of an asphalt mixing plant is generally as follows:

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 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.

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.

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.

drum asphalt mixing plant

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.

Asphalt mixing station is one of the most important equipment in processing operations, so how to build a website has become the focus of people’s attention. The editor has compiled some key points, hoping to be helpful to everyone.

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 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 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.

Building body frame for asphalt plant

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.

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.

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:

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.

METERING SYSTEM

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 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℃.

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.

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.

1: The site should be located on higher ground and away from residential areas and densely populated areas.
2: The venue should consider the transportation distance and choose a location with convenient transportation.
3: Determine the website construction plan according to the terrain

In fact, asphalt mixing stations are not uncommon in our daily lives. They are mainly a unit of equipment specially designed to mix asphalt. What we really don’t understand is the gas system of the asphalt mixing station. Only correct maintenance And operation can bring out the best production effect. So what are the faults in the gas circuit of asphalt mixing station?
The following three points are the more common gas path failures of asphalt mixing stations:

Asphalt mixing equipment has a special function, which is that it can perform cyclic heating to make the asphalt product reach the best condition. But how does it achieve this function? Everyone is curious about this.

Asphalt mixing plant refers to a complete set of equipment used for batch production of asphalt concrete. Its main function is to produce asphalt mixture, colored asphalt mixture, etc., and has been widely used in road construction. However, during the production process of asphalt mixture, pollutants such as noise, dust, and asphalt smoke will be produced, seriously polluting the environment and threatening the health of workers. Therefore, under the current background of building a resource-saving and environment-friendly society in our country, it is very important to save energy and reduce consumption during the use of asphalt mixing plants. The following article mainly starts from the three factors that affect the asphalt mixing plant, and explores the energy saving and consumption reduction measures of the asphalt mixing plant, aiming to reduce the cost of asphalt production and improve the efficiency of the asphalt plant.

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 using the asphalt mixing plant, you should regularly check the fuel pressure regulating valve or pressure reducing valve to determine whether the surface of the locking nut on the adjustable bolt is clean and removable; if the surface of the screw or nut is too dirty or rusty, it needs to be repaired or Replace the regulating valve.
Check the oil pump regularly to determine whether the sealing device is intact and whether the internal pressure is stable, and replace any damaged or leaking sealing devices. When using hot oil, check whether all oil pipes are well insulated. The filter installed between the oil tank and the oil pump must be cleaned regularly and checked for excessive wear to ensure that the fuel reaches the oil pump smoothly from the oil tank and to reduce the possibility of potential component failure.