belt conveyor used in the aggregate automatic feeding system

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.

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.

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:

Due to raw materials or usage, asphalt mixing plants will be subject to a certain degree of wear or other failures during daily use. If they are not controlled or repaired in time, the problem will be further exacerbated. For asphalt mixing plants, what are the ways to prevent wear and failure?
If the asphalt mixing plant is not treated in time after being worn, it may corrode once it is in contact with air, rainwater, etc. for a long time. If the parts of the asphalt mixing plant are severely corroded, the service life and normal operation of the entire equipment will be affected.

asphalt mixture mixer

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℃.

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:

In the construction industry, the installation and application of asphalt mixing plants can often be seen. This kind of equipment can complete the processing process of limestone and other powder products. The equipment has a reasonable structure and high working efficiency. It can save more costs for manufacturers during the production of asphalt raw materials. Therefore, the construction and other industries now attach great importance to the application of this equipment. During the production and processing of the equipment, the staff also need to pay attention to several operating skills to ensure that the equipment can operate stably and provide more benefits for production work.

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 batch asphalt mixing plant is equipped with an automatic cold aggregate feeding system, which consists of a silo, an automatic distributor and a feeding belt conveyor. fully enclosed automatic control has the advantages of stable feeding, fast speed, and improved operation efficiency of the whole station.

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.

Asphalt mixing equipment is also divided into fixed and mobile types. There are still big differences between the two to a certain extent. Let’s take a look at the design of mobile asphalt mixing equipment. What advantages can bring to the equipment?

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.

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.

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.

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 (composition: asphaltenes and resin) tanks are divided into: intermittent and continuous functions according to the production process: initial batching of aggregates, heating and drying, screening and measurement; heating and insulation of asphalt (composition: asphaltene and resin) , transportation and measurement; transportation and measurement of filler; uniformly mix the measured aggregate, asphalt (composition: asphaltene and resin), and filler into a finished product of a certain temperature.

Indonesia HMA-B1500 asphalt mixing plant in delivery，Features of this asphalt mixing plant

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.

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.

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.

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.

 Bitumen transport tanker

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.

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?

The plug valve is a rotary valve in the shape of a closure or plunger. After rotating 90 degrees, the channel opening on the valve plug is the same as or separated from the channel opening on the valve body to complete opening or closing. It is widely used in oilfield excavation, transportation and refining equipment, and such valves are also needed in asphalt mixing plants.
The valve plug of the plug valve in the asphalt mixing plant can be cylindrical or conical. In the cylindrical valve plug, the channel is generally rectangular; in the conical valve plug, the channel is trapezoidal. These shapes make the structure of the plug valve light and very suitable for blocking and connecting media and diversion.

drum asphalt mixing plant

Asphalt mixing plant equipment components