Emulsified asphalt production process and equipment | FEITENG

The production process of asphalt emulsion

Emulsified asphalt is mainly composed of the following five main materials: asphalt, water, emulsifiers, acids and modifiers, in order to store stable or in order to meet other special purposes, will be mixed with a small amount of additives. Emulsified asphalt production process can be divided into the following four processes: asphalt preparation, soap preparation, asphalt emulsification, emulsion storage.

1. Preparation of asphalt

Asphalt is the most important component of emulsified asphalt, generally accounted for the total mass of emulsified asphalt 50% -65%. When the emulsified asphalt spraying or mixing is completed, the emulsified asphalt emulsion, which the water evaporation is really left on the road surface is asphalt. Therefore, the preparation of asphalt is crucial.

According to the use of emulsified asphalt, select the appropriate asphalt brand and grade, asphalt preparation process is mainly the asphalt is heated and maintained at a suitable temperature process.

Asphalt preparation process is very important to control the temperature, if the asphalt temperature is too low, it will cause asphalt viscosity, flow difficulties, and thus emulsification difficulties; if the asphalt temperature is too high, on the one hand, it will cause asphalt aging, but also will make the emulsified asphalt export temperature is too high, affecting the stability of the emulsifier and the quality of emulsified asphalt. 2. Soap Preparation

According to the different emulsified asphalt required, select the appropriate type and dose of emulsifier and additive types and doses, configure the emulsifier aqueous solution (soap).

Depending on the emulsified asphalt equipment and the type of emulsifier, the preparation process of the aqueous solution of emulsifier (soap solution) also varies. For fully automated continuous emulsified asphalt production equipment, the soap solution of the various components (water, acid, emulsifier, etc.) are set by the production equipment itself to automatically complete the program, as long as the supply of each material can be ensured; for the semi-continuous or intermittent production equipment, you need to manually configure the soap solution in accordance with the recipe requirements. Some emulsifiers need to add acid to adjust the pH value of the aqueous solution, some (such as quaternary ammonium salts) do not need. Some emulsifiers that are solid at room temperature also need to be heated and melted before the soap is configured.

Soap into the emulsification equipment before the temperature is generally controlled between 55-75 ℃.

3. Emulsification of asphalt

Reasonable proportion of asphalt and soap together into the emulsifier, after pressurization, shear, grinding and other mechanical effects, so that the asphalt to form a uniform, fine particles, stable and uniformly dispersed in the soap, the formation of oil-in-water asphalt emulsion.

Suitable emulsified asphalt export temperature should be about 85 ℃.

4. Storage of emulsified asphalt

Emulsified asphalt from the emulsifier out, after cooling into the tank. Large storage tanks should be equipped with stirring devices, regular stirring. To slow down the emulsified asphalt segregation.

The classification of emulsified asphalt production equipment

1. According to the production process classification

Emulsified asphalt equipment in accordance with the process classification, can be divided into intermittent operation type, semi-continuous operation type, continuous operation type three. The process are shown in Figure 1-1 and Figure 1-2. As shown in Figure 1-1 intermittent modified emulsified asphalt production equipment, production of emulsifiers, acid, water, and latex modifiers, etc. in the soap blending tank blending, and then pumped to the colloid mill in the asphalt. A tank of soap is used up and then configure the soap, and then the next tank of production. When used in modified emulsified asphalt production, according to the different modification process, the latex pipeline can be connected to the colloid mill can also be connected to the colloid mill after the latex pipeline, or no special latex pipeline, but manually will be the prescribed dose of latex added to the soap solution.

Figure 1-1 intermittent emulsified asphalt plant production process

As shown in Figure 1-2 semi-continuous emulsified asphalt production equipment, in fact, is the intermittent emulsified asphalt equipment is equipped with more soap blending tanks, so that you can alternately blend soap, to ensure that uninterrupted soap into the colloid mill. At present, a considerable number of domestic emulsified asphalt production equipment belongs to this type.

Figure 1-2 Schematic diagram of semi-continuous (modified) emulsified asphalt production process

Continuous emulsified asphalt production equipment, emulsifier, water, acid, latex modifier, asphalt, etc., respectively, with metering pumps directly pumped into the colloid mill. Soap blending is done in the conveying pipeline.

2. According to the equipment configuration classification

According to the equipment configuration, layout and mobility, asphalt emulsification equipment can be divided into mobile, removable and fixed three. Mobile emulsified asphalt equipment is the emulsifier mixing device, emulsifier, asphalt pumps, control systems, etc. fixed in a special tray chassis. Because it can be transferred at any time to the production site, it is suitable for decentralized projects,

Use a small amount of frequently moving construction site emulsified asphalt preparation. Portable emulsified asphalt plant is the main assembly is installed in one or more than two standard containers, respectively, loaded and transported to achieve the site transfer, relying on the lifting gear quickly installed into the working state, the production capacity of such equipment has a large, medium and small different configurations. Can meet different engineering requirements. Fixed emulsified asphalt equipment generally rely on asphalt plant or asphalt mixing plant and other asphalt storage tanks, services within a certain distance from the more fixed customer groups. As suitable for China's national conditions, solid fixed emulsified asphalt plant is the main type of emulsified asphalt plant in China.