JPH0242963B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is applicable to replacement of existing asphalt pavement,
This relates to a device for recycling asphalt pavement waste materials generated during repair work, and sometimes in the construction of equipment buried under existing asphalt pavement.

Prior Art Asphalt pavement waste material (hereinafter referred to as "waste material") dug up during road construction, etc. can be fully used if it is heated and recycled, and generally it can be used with the aggregate heating equipment of a known asphalt plant. A certain dryer has been designed and used for heating waste materials, but the problem with heating and regenerating waste materials is that if the asphalt contained in the waste is heated too much, the asphalt will burn and produce exhaust gas. Oil smoke is generated inside the building, and this oil smoke is released from the chimney along with the exhaust gas.The exhaust smoke turns yellow, and when the water vapor disappears on a clear day, it becomes blue smoke, which has a foul odor and is a pollution that cannot be ignored. In order to suppress the amount of blue smoke generated, it is important not to heat the waste material more than necessary, and various measures have been taken in dryers for heating waste material in this regard.

Problems to be Solved by the Invention Blue smoke is generated when waste wood is heated in a dryer because there are a large amount of fine particles containing asphalt in the waste wood, and these fine particles have a small heat capacity, so they are overheated. This is thought to be because the asphalt particles adhering to the fine particles are burned, and because of their light weight, they are caught up in the gas flow passing through the dryer and carried away with the exhaust gas, and are emitted from the chimney.

Means for Solving the Problems The present invention has been made in view of the above-mentioned points, and includes a first rotary drum and a second rotary drum each having a large number of raking blades circumferentially disposed therein. The end portion is inserted into the second rotating drum, and both rotating drums are connected and rotatably pivoted, and the first rotating drum and the second rotating drum are connected.
A gas passage is provided surrounding the connecting part of the rotating drum,
The high temperature gas of the burner is passed through the gas passage to the first
and a second rotating drum, and a fan provided in an exhaust flue connected to the ends of both rotating drums sucks the high-temperature gas to maintain a gas flow in the opposite direction to the first rotating drum and the second rotating drum. Along with letting
The end of the exhaust flue connected to the first rotating drum is connected to the combustion chamber of the burner, and the waste material is introduced from one end of the first rotating drum and discharged from the other end of the second rotating drum. To provide an asphalt pavement waste recycling device which heats and recycles asphalt, prevents the generation of blue smoke, and does not reduce the quality of asphalt.

Example Hereinafter, the present invention will be explained based on examples.

1 has a number of raking blades 2 installed around it.
3 is a second rotating drum which also has a large number of raking blades 4 arranged around the inside thereof, and the diameter of the second rotating drum 3 is slightly larger than that of the first rotating drum 1; The end of the rotating drum 1 is
It is inserted into the rotating drum 3, and both drums are connected and fixed by a connecting plate 5. First rotating drum 1 and second rotating drum
The rotating drum 3 is supported by a support roller 7 provided on a base 6.
It is rotatably supported at an angle and rotated at a predetermined speed by a drive device (not shown). 8 is a burner which forms a flame in a combustion chamber 9, and causes the high-temperature gas to pass through a gas passage 10 formed by surrounding the connecting portion of the first rotating drum 1 and the second rotating drum 3, and to generate a flame in the first rotating drum. A fan (not shown) is fed into both drums from the joint between the first and second rotating drums 3 and provided at the end of the exhaust flue 11 of the second rotating drum 3.
maintains the gas flow passing through the second rotating drum 3 by suction, while the gas passing through the second rotating drum 3 is maintained by a fan 13 provided in the exhaust flue 12 of the first rotating drum 1. A gas flow in the opposite direction to the flow is maintained in the first rotating drum 1. The exhaust flue 12 is provided with a damper 14 for adjusting air volume,
The amount of gas passing through the first rotating drum 1 can be adjusted. The end of the exhaust flue 12 is connected to the combustion chamber 9 to circulate the exhaust gas and use it as secondary air and tertiary air for the burner 8.

The waste material is transferred to the first rotating drum 1 by a conveyor 15.
It is introduced from one end, rolls down the first and second rotating drums, and is discharged from the discharge section 16 of the second rotating drum 3.

When heating waste materials, the first rotary drum 1 is used during the preheating period of the waste materials, and the temperature of the waste materials is gradually increased using a countercurrent heating method with gas so as not to overheat particularly the fine particles in the waste materials. It softens the asphalt that adheres to it, increasing its adhesive strength, making the waste materials adhere to each other, increasing the size of the particles, and increasing their heat capacity. Therefore, if the temperature of the waste material to be raised during this preheating period is determined in terms of design, the amount of gas sucked by the fan 12, the length of the first rotating drum 1, etc. can be determined. In addition, during operation, the fan 1
It is also conceivable to adjust and control the amount of gas passing through the first rotary drum 1 by changing the number of rotations of the drum 1 and the degree of opening and closing of the damper 14.

The second rotating drum 3 is used during the heating period of the waste material, during which the temperature of the waste material is raised to a predetermined temperature. It is also conceivable to adjust and control by changing the rotation and the opening/closing degree of the damper to follow the combustion amount of the burner 8.

Function: In order to heat and regenerate waste materials, the first rotating drum 1 is
and into the second rotating drum 3, and the waste material is introduced into the first rotating drum 1 via the conveyor 15 while maintaining gas flows flowing in opposite directions in the first rotating drum 1 and the second rotating drum 3. . The thrown-in waste material is raked up by the raking blades 2 and rolled down the drum, while being heated by gas flowing in the opposite direction to the direction in which the waste material moves. Since the gas flow velocity is not high in the first rotating drum 1, it is unlikely that fine particles of waste materials will be carried away by the gas flow to the exhaust flue 12. For example, if vaporized asphalt is caught in the gas flow, However, the amount of blue smoke emitted from the chimney is suppressed because it is guided to the combustion chamber 9, where it is reburned and extinguished. Since this first rotary drum 1 uses a countercurrent heating system, the input waste material is gradually heated, and even the fine particles of waste material with a small heat capacity do not rise to an extreme temperature, and the asphalt content attached to the fine particles of waste material is also combusted. It softens without any
The adhesive strength is strengthened, and the fine particles of waste material adhere and bond to each other, increasing the size of the particles and increasing the heat capacity. The waste material, which has increased in size and has a larger heat capacity, is sent to the second rotating drum 3, where it is scraped up by scraping blades 4 and rolled down inside the drum by high-temperature gas flowing in the same direction as the waste material. However, since the fine grains of the waste material have increased in size and have a larger heat capacity, the temperature does not rise to an extreme level, and the asphalt adhering to the waste material is less likely to burn or deteriorate, and there is also an increase in weight due to the increase in grain size. They are less likely to be caught up in the gas flow and carried away. The waste material is heated to a desired temperature within the second rotary drum 3, discharged from the discharge section 16, and reused as recycled composite material.

Effects of the Invention As described above, according to the present invention, the waste material is preheated in the first rotating drum 1, the asphalt components adhering to the waste material are heated and softened without being burned, increasing the adhesive strength, and the fine particles of the waste material are reduced. After increasing the grain size and increasing the heat capacity, it is sent to the second rotary drum 3 and heated to the desired temperature, so the temperature of the fine waste material does not rise to an extreme level, and the asphalt attached to the fine grains is not burned. Moreover, the amount of blue smoke discharged from the chimney is suppressed to the utmost because the fine particles are less likely to be caught up in the gas flow and carried away due to particle enlargement. Furthermore, even if the vaporized asphalt is carried away by the gas flow passing through the first rotating drum 1, it is guided to the combustion chamber 9 and re-burned, so that the amount of blue smoke can also be suppressed. It is.

Furthermore, since the asphalt component is not heated to an extreme degree, there is little deterioration of the asphalt, and a recycled composite material of good quality can be produced.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional front view of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... First rotary dryer, 3... Second rotary dryer, 8... Burner, 9... Combustion chamber, 10... Gas passage, 11, 12... Exhaust flue, 13... Fan, 15
...conveyor, 16...discharge section.

Claims (1)

[Claims] 1 A first rotary drum and a second rotary drum each having a large number of raking blades arranged around the inside thereof are provided, and the end of the first rotary drum is inserted into the second rotary drum, and both rotary drums are connected to enable free rotation. A gas passage is provided surrounding the connecting portion of the first rotating drum and the second rotating drum, and high-temperature gas from the burner is sent to the first and second rotating drums through the gas passage. A fan installed in an exhaust flue connected to the end of the exhaust flue sucks high-temperature gas to maintain gas flow in opposite directions to the first rotating drum and the second rotating drum, and the exhaust flue connected to the first rotating drum Recycling of asphalt pavement waste material, characterized in that the end of the flue is connected to the combustion chamber of a burner, and the waste material is introduced from one end of the first rotating drum and discharged from the other end of the second rotating drum. Device.