Asphalt concrete mixing equipment is a mechanical device for producing various asphalt mixtures. It is suitable for engineering departments such as highways, cities, roads, airports, docks, parking lots, and freight yards. The function of the asphalt concrete mixing equipment is that the aggregates and fillers of different particle sizes are mixed together in a specified ratio, using asphalt as a binder, and mixed into a uniform mixture at a specified temperature. Commonly used asphalt mixtures include concrete, asphalt gravel, and asphalt sand. Asphalt concrete mixing equipment is one of the key equipment for asphalt pavement construction, and its performance directly affects the quality of the paved asphalt pavement.

Nowadays, in the development of asphalt mixing equipment, the modular combination design principle is usually adopted in consideration of the calling of parts and components, which is the basis of the structure of modern mixing equipment. The standardized generalization coefficient is 80% on average.

In the mixing equipment, the measurement process, the unloading of the finished product mixture and the automation of the heating of the mineral material should be ensured. The mixing equipment must have a high human-machine environment index.

Asphalt concrete mixing equipment has a long history abroad, and it has been published as early as this century. After a long period of development, especially with the increasing improvement of electronic technology and the rapid advancement of computer technology and information processing technology, asphalt concrete mixing equipment has reached a very high level in developed countries, and it is still constantly improving, and the product replacement is faster.

The overall level can be summarized as follows:

a) Production capacity serialization

At present, the specifications of asphalt concrete mixing equipment in the international market are very

Complete, there are small equipment with an output of several tons per hour, and large equipment with an output of thousands of tons per hour. The most used are various small and medium-sized equipment below 350t / h. However, with the commercialization of asphalt concrete materials, the preparation of asphalt concrete is developing in the direction of professional factoryization, the production capacity of asphalt concrete mixing equipment is also becoming larger, and the production capacity of intermittent forced mixing equipment has reached 700t/h. The production capacity of continuous drum mixing equipment can reach up to 400t/h.

b) Advanced technical performance In order to meet the needs of the project for the quality of finished products, in order to meet the social requirements for energy saving and environmental protection, the technical indicators of the equipment are getting higher and higher. At present, the measurement accuracy of aggregates and powders is 0.5% for intermittent forced mixing equipment and 1% for continuous drum mixing equipment; the accuracy for asphalt measurement is 0.33% for intermittent forced mixing equipment and 0.5% for continuous drum mixing equipment; the thermal efficiency can be Up to 80% -85%; the dust emission can be controlled within 5omg / m3.

c) Control operation automation Whether it is intermittent forced or continuous drum-type mixing equipment, the control system adopts computer management and sets the control method of combining microcomputer program control and manual; the process of the equipment can be simulated on the display screen. And it has automatic fault diagnosis and alarm function; it has various data display and printing functions in the production process. In addition, a large number of grading formulas can be stored for replacement when needed.

The paddle mixer is the final main device of the asphalt concrete mixture mixing equipment and the whole process of preparing the road mixture. In the mixer, the sand, gravel, mineral powder and asphalt with a certain proportion will be evenly mixed into the desired finished material-asphalt concrete mixture. Minerals have a decisive influence on the coating performance of asphalt. The mixture of asphalt and mineral powder is called asphalt binder.

A. Aggregate

a) The average static dust density of cold aggregate is 21 / m

b) When using ordinary asphalt, the maximum temperature of the aggregate in the drying barrel of the drying barrel should not be higher than 150c.

c) When the average moisture content of the aggregate is 3%, the rated productivity is 160t/h (surface moisture content).

d) The cold aggregate must be clean and should not contain too much dirt or debris.

e) The gradation of cold aggregate should be continuous.

f) Cold aggregates must not contain a large amount of over-spec materials, otherwise the channel will be blocked and the feed capacity will be reduced accordingly.

B. Type of asphalt mixture.

The type of asphalt mixture produced by this machine must meet the relevant national standards.

C. Operating conditions

a) Equipment operation must be continuous operation.

b) The discharge temperature of the mixture should generally not be higher than 150c or 180 ° c.

D. Powder

The water content of the powder must be less than 0.5%, and there should be no lumps or arches, otherwise it will form the phenomenon of material breakage and waiting, which will affect the output.