Necessary stages in asphalt mixing plant design

Asphalt concrete mixing equipment generally uses conveyor belt conveyors to transport cold materials. Its main advantages are large conveying capacity, continuous operation, simple equipment structure and automatic control. However, belt deviation is a common fault, which directly affects the drying operation of the drying drum and also affects the production efficiency of the mixing equipment. Therefore, it is very important for the asphalt mixing station to solve the belt deviation problem at the operation site of the asphalt concrete mixing equipment.

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.

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.

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.

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 station is the standard for mixing asphalt. Having said that, many people still think that this has nothing to do with us. We don’t use asphalt, but do you know that our roads are made of asphalt? When I was a child, I used asphalt to pluck pig hair. The hair on the pig’s head was indeed clean. When using asphalt, it must be burned hot, because if it is cold, it will be very hard and cannot be used. Therefore, if a large amount of asphalt is needed, there must be an asphalt mixer because there is no more convenient equipment than it.
What kind of source material is asphalt that requires special equipment. Asphalt is a black-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. At the same time, it is also a waterproof, moisture-proof and anti-corrosion organic gelling material. It can be mainly divided into three types: coal tar asphalt, petroleum asphalt and natural asphalt. Asphalt is mainly used in industries such as coatings, plastics, rubber, and paving roads.

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

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.

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.

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.

Modified Bitumen

The drying drum of the asphalt mixing plant should pay attention to daily inspection, correct operation and reasonable maintenance, so as to extend its service life and reduce the cost of engineering use.
1. Pay attention to daily inspection. Before the asphalt mixing plant officially works, the drying drum needs to be tested and inspected to see whether each pipeline is reliably connected, whether the lubrication of the whole machine is feasible, whether the motor can be started, whether the functions of each pressure valve are stable, whether the instrument is normal, etc.
2. Correct operation of the mixing station. At the beginning of the asphalt mixing plant, manual operation can only switch to automatic control after reaching the specified production capacity and discharge temperature. The aggregate should be dry and have a standard mode so that it can maintain a constant temperature when flowing through the drying drum. When the entire aggregate is sent to dry, the moisture content will change. At this time, the burner should be used frequently to compensate for the change in moisture. During the rolling stone processing, the amount of water directly formed is basically unchanged, the amount of combustion accumulation increases, and the amount of water in the deposited accumulation material may change.
3. Reasonable maintenance of the asphalt mixing plant. Aggregates should be deactivated when the asphalt mixing plant is not in operation. After work every day, the equipment should be operated to discharge the aggregate into the dryer. When the material in the hopper leaves the combustion chamber, the combustion chamber should be closed and allowed to idle for about 30 minutes to cool down, so as to reduce its impact or make the machine run in a straight line. Install the drying cylinder fixing ring on all rollers synchronously.

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.

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.

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.

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 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.

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.

If you look at an asphalt mixing plant from a professional perspective, do you know how to judge its work and significance? In fact, the so-called asphalt mixing station is the one that produces asphalt. We can usually see it in road construction projects. Specifically, it mixes some materials that need to be used during the construction process according to certain proportion requirements. Then complete the corresponding construction work.
Then, we can analyze it from a market perspective. Since it was used in the market, it has been widely praised by users. Today’s asphalt mixing plant technology has been greatly improved, and the entire set of equipment used has a variety of advantages. , such as meeting the requirements of stable control, screening, efficient dust removal, excellent mixing, and green environmental protection during the work process. It is even more obvious when used in large-scale projects such as high-grade highways and airports.

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.

The first step in establishing an asphalt mixing station is to determine the host machine and feed batching system. Generally, the configuration is based on the project’s construction period, total amount of concrete, daily concrete consumption and other indicators. The basic principle is to meet the daily concrete consumption. Under normal circumstances, a project can only have one asphalt mixing station, or separate mixing stations can be set up according to zones, or a large mixing station can be set up together with an appropriate number of concrete transport trucks, all of which depend on the actual situation.

In order to keep the asphalt mixing plant in a stable operating process, a series of adverse factors related to it must be excluded. What should be paid attention to in this process?
First of all, the selection of the delivery pump in the asphalt mixing plant must meet the requirements of asphalt pouring per unit time during construction, height, and horizontal distance requirements. At the same time, there must be a certain technical and production capacity reserve, and the balanced production capacity is preferably 1.2 to 1.5 times.
Secondly, the movement and hydraulic systems of the asphalt mixing plant must be normal, and there must be no abnormal sound and vibration to avoid large aggregates and lumps inside the equipment, otherwise it is easy to get stuck at the feed inlet of the mixing plant or be blocked due to arching. Another point is that when the asphalt mixing plant is in the same site, it is not suitable to use too many pumps and pumps from multiple manufacturers to avoid affecting its normal operation.

[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 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.

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 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.

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.

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.