JPH0115644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a technology for recycling asphalt waste material generated during asphalt road surface repair work, conduit work buried under roads, etc. as a heating mixture. This invention relates to a method for recycling asphalt waste material, in which the asphalt waste material thus generated is passed through a crusher to adjust its particle size, and then the asphalt waste material whose particle size has been adjusted is put into a dryer and heated to the required temperature for recycling.

Conventionally, in the above-mentioned recycling method, all of the asphalt waste that has been crushed by the crusher and whose particle size has been adjusted is placed in a dryer and heated without particle size sorting. Small particles in the middle (fine particles in the particle size range of 0 to 5 mm) soften due to a sudden rise in temperature and adhere to the inner wall surface of the dryer. As a result, not only does the heating efficiency decrease over time, but also the adhesion There is an inconvenience in that it takes time to maintain the dryer such as removing particles, and in addition,
When all waste materials are heated to reach the required temperature for recycling,
If the fine particles are burned or overheated above the deterioration temperature, many impurities will be included in the exhaust gas, causing pollution problems and deteriorating the quality of the recycled composite material. There were flaws.

In addition, as a means to eliminate or suppress the above-mentioned inconveniences and drawbacks, there are conventional methods such as ○I, which introduces small particles from the middle of the dryer, and ○B, which involves pre-spraying small particles with water and allowing them to rise in the dryer. Methods of suppressing the temperature rate are known, but when these methods are used,
It is necessary to strictly adjust the amount of water added to the midway point of the dryer and the amount of water sprinkled depending on the fluctuation of the ratio of the amount of fine particles to the amount of total waste material. If the water input amount is not adjusted or is improperly adjusted, not only will the above-mentioned inconveniences and drawbacks not be eliminated or suppressed, but it will even promote loss of thermal efficiency and deterioration of quality. This could result in Therefore,
In order for the above countermeasures to be effective, equipment for high-precision automatic adjustment of the input amount and watering amount, as well as operating costs, are required, which has the disadvantage of causing a significant increase in regeneration costs. .

In view of these circumstances, the present invention proposes a method that improves heating efficiency and regenerates high-quality composite material by adding a process that is relatively simple in terms of equipment and can be realized advantageously in terms of cost. Have a purpose in mind.

The method for recycling asphalt waste according to the present invention proposed with the above object in mind is that in the method detailed at the beginning, the asphalt waste whose particle size has been adjusted before being put into the dryer is passed through a granulator, and the small particles in the waste are passed through a granulator. It is characterized by agglomerating particles of a certain size.

That is, the small particles in asphalt waste whose particle size has been adjusted by crushing are aggregated using relatively simple and economical equipment such as granulation means to increase the apparent particle size. By doing so,
To avoid as much as possible the inconvenience of fine particles adhering to the inner wall surface of the dryer, the resulting reduction in heating efficiency, and the troublesome maintenance of the dryer, while all waste materials are fed into the dryer at the same time and from the same location. Not only is it possible to reduce the amount of impurities in the exhaust gas, but because the particle size of all the waste materials to be heated in the dryer is almost the same, there is no risk of some materials burning or being overheated above the deterioration temperature, and the impurity content in the exhaust gas can be reduced. Reliably achieves the effects of facilitating pollution countermeasures due to reduction in pollution, improving the quality of recycled composite material, and increasing the composite material recycling rate, regardless of fluctuations in the fine particle content due to crushing. I was able to do it.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail in order of steps based on illustrative drawings.

First step Asphalt waste material A generated from road construction etc. is supplied to the crusher 1 through the hopper 1a and coarsely crushed, and then passed through the sieve 3 to produce waste material A ₁ on the sieve.
Two types of sieve intermediate waste material A ₂ with different particle sizes,
It is classified into four types: A ₃ and sieve waste material A ₄ . The classified waste material _A1 on the sieve is crushed by a crusher 1 different from the one described above, and then fed back to the sieve 3, thereby increasing the composite material regeneration rate.

2nd process Out of the waste materials classified in the 1st process, the waste material under the sieve A ₄ , which has the smallest particle size, was passed through the granulator 4 to aggregate it, thereby increasing the apparent particle size. Waste material A′ ₄ and two types of sieve intermediate waste materials A ₂ and A ₃ are each placed in the hopper 5.
to be accommodated.

Third step Each waste material A′ ₄ accommodated in the hopper 5,
Mix A ₂ and A ₃ in an appropriate ratio (mixed so that it falls within the specified aggregate true particle size range), and then dry it in a drum dryer 2.
The dryer is heated to the required regeneration temperature by spirally transferring the high-temperature combustion gas along the two axial directions of the dryer. At this time, the combustion exhaust gas passes through the dust collector 6 to remove solids contained in the exhaust gas, and is released into the atmosphere.

Fourth step: The heated waste material is supplied to the mixer 7, and a predetermined amount of straight asphalt A ₅ and an appropriate amount of softener B are added to the heated waste material and mixed for an appropriate period of time to produce a recycled composite material. . This recycled composite material is stored, for example, in a heat-insulated silo 8, and is carried out as needed.

Incidentally, in the method of the present invention, classification using the sieve 3 is not necessarily necessary, and all the crushed waste materials may be passed through a granulator 4 so that all the waste materials are approximately uniform and the apparent particle size is increased.

[Brief explanation of drawings]

The drawing is a flow sheet illustrating an embodiment of the method for recycling asphalt waste according to the present invention. 1...Crusher, 2...Dryer, 3...Sieve, 4
...granulator.

Claims (1)

[Scope of Claims] 1. Asphalt waste material generated from road construction, etc. is passed through a crusher 1 to adjust its particle size, and then the asphalt waste material whose particle size has been adjusted is put into a dryer 2 and heated to the required temperature for recycling. The asphalt waste recycling method is characterized in that the asphalt waste material whose particle size has been adjusted before being input into the dryer 2 is passed through a granulator 4 to aggregate small particles in the waste material. Method. 2. The asphalt waste crushed by the crusher 1 is classified into a plurality of types through a sieve 3, of which only small particles are passed through the granulator 4. The method for recycling asphalt waste material according to item 1.