JPH0450892Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a stirring blade that prevents the adhesion of aggregate containing asphalt in a drying and heating drum of a recycling asphalt plant or a drum mixing asphalt plant.

[Conventional technology]

Recently, in order to effectively reuse asphalt pavement waste, a mixture obtained by mixing new aggregate and recycled material, ie, pavement waste, in an arbitrary ratio is applied to the paved surface.

This asphalt plant is shown in Figure 3.

The new aggregate a stored in the cold bin 1 and the recycled material b such as pavement waste stored in the cold bin 2 are powder c such as stone powder sent from the silo 3.
Together with this, they are fed into the drum dryer 4 and mixed. Further, an appropriate amount of asphalt is supplied from the asphalt tank 5 to the drum dryer 4 and kneaded. The mixture thus kneaded is transferred to the skip 7 via the after mixer 6 and transported to a predetermined location. The dust-containing exhaust gas d generated at this time is separated into large particles by a dry cyclone 8, and then sent to a wet dust collector 10 by an exhaust fan 9, where fine dust particles are separated. Through this process, the exhaust gas purified to a level below the pollution regulation value is released into the atmosphere.

By the way, aggregates containing asphalt, such as asphalt concrete recycled aggregates, are dried in drum dryer 4.
During heating and drying, as shown in FIG. 4, material feeding blades 12 and stirring blades 13 are formed on the inner wall of the drum dryer 4 which is driven to rotate in an inclined state to stir the material. Of these, stirring blade 1
3 has an L-shaped cross section attached to the inner wall of the drum dryer 4 as shown in FIG. 5, and the conventional structure was to stir the material while scraping it up.

[Problem that the invention attempts to solve]

In the drum dryer 4, the material to be dried is fed by a belt conveyor or the like, and the feed blades 12
is sent inside the drum. On the other hand, a burner 11 is provided on the inlet side of the drum dryer 4, and the asphalt in the material to be dried is dissolved by the heat thereof and kneaded with the aggregate. As the material to be dried is transported to the exit side of the drum dryer 4, its temperature increases, and the material is transported to the exit side by the stirring blade 13 while being heated and mixed.

However, when the material to be dried is dried and heated using the stirring blade 13 as shown in FIG. The dry matter adheres to the base of the stirring blade 13 and gradually grows, and becomes clinker-like due to the heat of the burner 11, so it is necessary to periodically remove it, and this work takes a long time. was.

The present invention was devised to solve these problems in the prior art, and provides a stirring blade with a structure that prevents aggregates containing asphalt from adhering, especially in the portion of the drum where it begins to dissolve. The purpose is to

[Means for solving problems]

The stirring blade of the drum for drying and heating of the present invention is one of the stirring blades 14, 15, 16 in the drum 4 for drying and heating asphalt pavement waste material or asphalt and aggregate while kneading with the stirring blades 14, 15, 16. , the stirring blades 14 provided in the portion D in the drum 4 where the asphalt component in the material to be dried begins to dissolve are arranged in a concave shape with a ridgeline pointing toward the axis of the drum 4 and a center line of curvature parallel to the ridgeline. It is characterized by having a shape having both side surfaces curved in a direction.

[Effect]

The shape of the stirring blade in the part of the drum where the asphalt in the material to be dried begins to dissolve is as described above, so that the stirring blade itself is shaped so that it does not get caught, and the base of the stirring blade and the drum The boundary at the joint with the inner wall is smooth, so that there is significantly less material adhesion or accumulation in that area, and the material is gradually transferred to the end of the drum while being stirred.

〔Example〕

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of a drum dryer equipped with stirring blades according to the present invention, and FIG. 2 is a cross-sectional view showing the shape of the blades in various parts.

In the figure, 11 is a burner provided on the input side of the drum dryer 4. In the input section A of the drum dryer 4, as shown in FIG. The materials and aggregates containing asphalt, which have been carried by the belt conveyor 17, are sent into the drum dryer 4. In part B of the drum dryer 4, when the material is scraped up, the material is burned by the flame of the burner 11, so no blades are provided in this part. The next section C is provided with a feeding vane 12 as shown in FIG. 2a, like the section A, in order to feed the material into the section D where the material begins to melt.

The stirring blade 14, which is a feature of the present invention, is provided in the portion D where the material begins to melt as described above, and the center line of curvature is parallel to the ridge line pointing to the axis of the drum dryer 4, and the ridge line is parallel to the ridge line. It has a shape with both sides curved in a concave shape. The stirring blades 14 are provided at a small inclination angle with respect to the central axis of the drum dryer 4.
Because of this shape, the stirring blade 14 itself has a shape that makes it difficult for materials that do not get caught to adhere to it, and the boundary between the joint between the root of the stirring blade 14 and the inner wall of the drum dryer 4 is smooth. Therefore, there is significantly less adhesion or accumulation of material in that area, and the material is gradually transferred while being stirred. The materials stirred and mixed by the stirring blade 14 in the portion D are heated in the portion E while being conveyed by the stirring blade 15 having a concave shape as shown in FIG. 2c. Furthermore, in the next part F, as shown in FIG.
The material is kneaded to a predetermined temperature and water content ratio by repeating stirring and falling using a stirring blade 16 having a diameter, and then sent to the next step.

[Effect of idea]

As explained above, in the present invention, the stirring blades provided in the part of the drum where the material begins to melt are arranged in a concave shape, with the ridgeline pointing toward the axis of the drum and the center line of curvature parallel to the ridgeline. It has a shape with both curved side surfaces. For this reason, in addition to the stirring blade itself having a shape that does not get caught, the boundary between the root of the stirring blade and the inner wall of the drum is smooth, and there is significantly less adhesion of materials to be dried at that part. Compared to conventional stirring blades, the removal interval can be significantly longer.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a drum dryer equipped with stirring blades according to the present invention, Fig. 2 is a cross-sectional view showing examples of various types of blades installed in the present invention, and Fig. 3 is a flow diagram showing an example of an asphalt plant. , FIG. 4 is a sectional view of a drying drum, and FIG. 5 is a sectional view showing the structure of a conventional stirring blade. 4...Drum dryer, 11...Burner, 12
...Feeding blade, 14-16...Stirring blade,
17... Belt conveyor.

Claims (1)

[Claims for Utility Model Registration] In a drum 4 for drying and heating asphalt pavement waste material or asphalt and aggregate while kneading them with stirring blades 14, 15, 16, among the stirring blades 14, 15, 16, the drum 4 The stirring blades 14 provided in the portion D where the asphalt content in the material to be dried begins to dissolve are placed between the ridgeline pointing to the axis of the drum 4 and both sides curved in a concave shape, each with a center line of curvature parallel to the ridgeline. A stirring blade for a drum for drying and heating, characterized in that it has a shape having a surface.