Analysis of the application advantages of PLC in asphalt mixing plants

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.

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.

The hydraulic reversing valve of asphalt mixing plants is generally not prone to failure, but occasionally there may be untimely phase change, gas leakage, electromagnetic induction pilot valve, etc., and the corresponding fault causes and treatment methods are naturally different.
If the hydraulic reversing valve does not change phase in time, it is mostly caused by poor finish, spring stuck or damaged, oil stains or residue stuck in the drag part, etc. It is necessary to check the condition of the pneumatic triplex and the viscosity of the grease. If necessary, the grease or other parts can be replaced.
During long-term use, the hydraulic reversing valve of the asphalt mixing plant is prone to damage to the valve core sealing ring, valve seat and high-pressure gate valve, causing gas leakage in the valve. At this time, the sealing ring, valve seat and high-pressure gate valve should be replaced, or the hydraulic reversing valve should be replaced in time.
Therefore, in order to more effectively reduce the equipment failure rate of the asphalt mixing plant, it is also necessary to pay attention to the maintenance of machinery and parts.

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.

Asphalt mixing plants play a big role in industry. Before talking about asphalt mixing plants, let’s first understand asphalt. Asphalt is a dark brown, high-viscosity organic liquid composed of hydrocarbons and non-metallic substances of different molecular weights. The surface is black and soluble in carbon disulfide. It is a waterproof, moisture-proof and anti-corrosion organic gelling material. When it comes to asphalt, it can be mainly divided into three types: coal tar asphalt, petroleum asphalt and natural asphalt: among them, coal tar asphalt is a by-product of coking. Petroleum asphalt is the residue after crude oil distillation. Natural asphalt is stored underground, and some form mineral layers or accumulate on the surface of the earth’s crust.

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 plant also needs to be powered on for trial operation before it is officially put into work.
The first step in commissioning is to run a single motor and 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.

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.

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.

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.

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.

When using an asphalt mixing plant, first of all, it needs to have good stability. If it does not have good stability, then the asphalt mixing plant will not be able to meet the requirements of the project in terms of requirements or mass production. For road construction, the measurement requirements of asphalt concrete are relatively strict and precise. Only qualified asphalt concrete can make the quality of road construction meet the actual requirements. Therefore, the stability of the asphalt mixing plant is very important.
Secondly, the requirements for the asphalt mixing plant when in use are that the equipment should be as simple as possible on the basis of having all the required functions, and the overall operation should be reduced as much as possible. This can save a lot of manpower input during operation and save corresponding costs. Although it is simple, it does not mean that the technological content of the asphalt mixing plant needs to be reduced.
The above are the requirements that the asphalt mixing plant needs to meet when in use, because if each equipment wants its working effect to achieve the expected appearance, the equipment itself needs to have corresponding conditions. It must be a qualified and convenient equipment to ensure the efficiency and quality of the work.

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.

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.

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?

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.

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.

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?

Asphalt mixing stations are constructed according to a certain process, which can not only ensure the construction quality, but also ensure that the asphalt mixing station is not damaged. Although construction details are critical, the key skills of asphalt mixing station construction must be mastered.
Before the construction of the asphalt mixing plant, the top surface of the asphalt mixing station construction range should be removed, and the site elevation should be kept dry and flat to meet the design requirements. If the surface is too soft, the foundation should be reinforced to prevent the construction machinery from losing stability and ensure that the pile frame is vertical.
Then the on-site construction machinery should be inspected to ensure that the machinery is intact and assembled and tested under the premise of meeting the requirements. To ensure the verticality of the asphalt mixing plant, the deviation of the gantry guide and the mixing shaft from the verticality of the ground shall not exceed 1.0%. Asphalt mixer manufacturer.

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.

Bitumen, a black or brown petroleum-like material, has a viscosity ranging from a viscous liquid to a glassy solid. It can be obtained as a residue separated from natural deposits. Bitumen consists of hydrogen and carbon compounds with small amounts of nitrogen, sulfur and oxygen. The preparation of mixed materials for mixing with asphalt is done in several steps:
Prediction: According to the asphalt recipe, the individual components of the aggregate are weighed. Usually this is done using a belt scale, since the material must go to the next step in a continuous flow.

Asphalt flue gas treatment methods, their principles and characteristics, and an asphalt flue gas environmental protection treatment plan based on the actual asphalt flue gas problems faced by the unit.

1. Basic situation
My unit’s mixing plant is equipped with a 4000-type asphalt mixing plant. During daily production of the asphalt mixing plant, a large amount of asphalt smoke will be emitted from the mixing pot discharge port. This smoke not only has an unpleasant smell, but also contains A large number of compounds that are harmful to the human body, such as benzopyrene, benzanthracene, carbazole and other polycyclic aromatic hydrocarbons, mostly have carcinogenic risks. Smoke overflow will cause pollution to the surrounding atmospheric environment and affect the personal health of workers. Although the overflow port of the mixing station is equipped with a dust retaining wall, the fine dust is seriously raised, and the cold material belt conveyor is dusty. In order to protect the environment, reduce pollution, and reduce cost investment, based on full research and absorption of technology in the same industry, and combined with the actual situation of asphalt mixing, we are planning to install asphalt mixing bag dust collectors to the flue at the discharge port of the mixing pot to control asphalt fumes. Gas is processed. The dust removal efficiency of the bag dust collector can reach 97%~99%, and the dust-containing gas can be purified to a level of 50mg/Nm3.

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.

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.

[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.

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.

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 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.