JPH0160603B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the production of regenerated heated bituminous mixture using bituminous pavement waste, and in particular to heating the bituminous pavement waste without contacting with the flame of a burner. The invention relates to a method and an apparatus for the same.

[Conventional technology]

Conventionally, a heating device called a dryer in an asphalt plant that heats aggregates has a rotating cylindrical body with a fixed rotation speed that is tilted in the longitudinal direction and supported, and the lower opening of the body is covered with a fixed proximal wall. A burner is attached to the base end wall, and an aggregate recovery port is provided. The upper opening is covered by a fixed proximal wall, and the proximal wall is provided with a chute for introducing new aggregate and an exhaust duct for exhausting and removing dust from the cylindrical body.

In addition, a raking blade, a check blade, etc. are attached to the inner wall of the rotating cylindrical body. In such conventional heating devices, when the material to be heated is charged through the input chute and heated by the burner by rotating the rotating cylinder, the material to be heated is swept around the inner circumference of the cylinder by the scraping blades as the rotating cylinder rotates. The surface is scraped up from the bottom upwards, and as it falls repeatedly, it is heated, moves gently toward the collection port, and is collected.

[Problem that the invention seeks to solve]

When producing a recycled heated bituminous mixture using bituminous pavement waste, if conventional facilities are used, new aggregate and bituminous pavement waste are introduced from the aggregate input chute on the upper proximal wall of the dryer, and then the burner is heated. Because the bituminous pavement waste is heated directly with flames, the bitumen contained in the bituminous pavement waste is combusted, producing blue and yellow smoke containing nitrogen dioxide, sulfur dioxide, aldehydes, etc., and spraying foul-smelling droplets to nearby residents. In addition, the filter cloth of the dust collector located at the end of the exhaust duct may become clogged, and the bituminous material may be carbonized, causing deterioration of the quality of the regenerated heated bituminous mixture such as strength deterioration and embrittlement. There were problems such as:

On the other hand, bituminous pavement waste generated from bituminous pavement repair work has been designated as industrial waste, and the amount generated has been increasing year by year, and a way to effectively recycle it has been sought for a long time.

[Means for solving problems]

The present invention has been devised to provide a method for heating and mixing new aggregate and bituminous pavement waste together, and a heating device for the same, in order to solve the problems of the conventional techniques. As a specific measure, (1) new aggregate heated in a rotating cylinder is discharged into a kneading section provided at the outer periphery of the lower opening of the rotating cylinder, and bituminous pavement waste is introduced into the kneading section. The bituminous material is characterized by kneading the new aggregate heated with the bituminous pavement waste and indirectly heating the pavement waste through heat exchange so as to combine the bituminous pavement waste as an aggregate of the recycled bituminous mixture. (2) At the upper opening of a rotating cylindrical body tilted in the longitudinal direction and freely rotatable in the circumferential direction by a drive mechanism,
The upper wall body with an input chute for inputting new aggregate is loosely fitted and covered, and a large diameter cylinder is fitted onto the outer periphery of the lower opening and combined with and integrated with the rotating cylinder. A kneading section is formed by attaching kneading blades to the circumferential surface of the body, and a lower lid body is loosely fitted into the lower opening of the large-diameter cylinder, and the lower lid body has bituminous material directed toward the kneading section. The heating device for bituminous pavement waste is characterized in that it is equipped with an input chute for inputting pavement waste and a burner directed into a rotating cylindrical body avoiding the input chute, and furthermore, the rotation of the cylindrical body is controlled by an inverter. A motor whose rotational speed is variably controlled by the inverter, a pulley that transmits the rotational force of the motor, a support roller rotated via a speed reducer, and a drum roller that rotates in frictional contact with the support roller. This device was constructed as a heating device for bituminous pavement waste, which is characterized by the following.

[Effect]

According to the present invention, the new aggregate is heated in the rotating cylinder and then discharged to the kneading section, and the pavement waste is thrown into the kneading section without directly coming into contact with the flame of the burner, and the new aggregate is heated. Aggregate and unheated pavement waste are kneaded in the mixing section, and the pavement waste is heated by heat exchange between the new aggregate and the pavement waste, and can be mixed and integrated as aggregate for the recycled bituminous mixture.

In addition, the rotation of the rotating cylinder changes the amount of new aggregate input depending on the amount of bituminous pavement waste mixed in.
The rotation speed was controlled by an inverter to accommodate this change, making it possible to obtain the desired target temperature even if the amount of new aggregate changed.

〔Example〕

Embodiments of the present invention will be described based on the drawings. FIG. 1 is a side sectional view of the heating device.

The rotating cylindrical body 2 of the heating device 1 has annular drum rollers 2a, 2a fitted on the circumferential surface of both ends in the longitudinal direction, and the drum rollers 2a, 2a portions are mounted and supported on support rollers 3, 3. , are installed on the support base 4 in an inclined manner in the longitudinal direction, and the drum rollers 2a,
2a is configured to rotate in frictional contact with support rollers 3, 3. Further, scraping blades 4a and 4b are attached to the inner surface of the rotating cylinder 2 at appropriate intervals along the inner circumferential surface and at appropriate intervals in the longitudinal direction, and non-returning blades are attached to the inner circumferential edge on the inclined upper side. Wings 4c are attached at appropriate intervals along the inner peripheral surface.

The drive mechanism for rotating the rotary cylindrical body rotates the drum roller 2a by frictional driving of the support rollers 3, 3, which are composed of four pairs of two pairs. As shown in FIG. 1, a roller shaft 3a is connected to a decelerator 3b, and the decelerator 3b is connected to a motor 3d via a pulley 3c. The motor 3d is connected to a power source via an inverter (not shown), and is configured so that the number of revolutions of the motor can be variably controlled to a desired number. Therefore, the quality (for example, water content ratio, bituminous content, etc.) and amount of input (mixing ratio with respect to new aggregate) of the bituminous waste input into the rotating cylindrical body 2
In order to rotate the rotating cylindrical body at a desired rotational speed by, for example, the motor is arbitrarily controlled to rotate at a rotational speed corresponding to the desired rotational speed of the rotating cylindrical body.

As a result, even if the heating capacity of the burner is constant and the speed reducer is a specific object, the rotation speed of the rotating cylinder can be controlled by freely controlling the rotation speed of the motor, and the bitumen is charged. It is possible to uniformly increase the maximum thermal efficiency of the burner in response to changes in the mass of pavement waste.

The upper opening 2b of the rotating cylindrical body 2 is covered with an upper wall 5 fixed to the support 4.
The upper wall body 5 has an annular wall 5b integrally attached to the periphery of the circular wall plate 5a, and the annular wall 5b is fitted onto the rotating cylindrical body 2. A suitable space is formed between the opposing surfaces to prevent rotation. sliding contact is prevented. Further, a charging chute 6 for charging new aggregate is attached to the wall plate 5a.

A truncated conical drum as a large-diameter cylinder 7 is fitted on the outer peripheral edge of the lower opening 2c of the rotating cylindrical body 2 so as to expand upwardly. This large-diameter cylinder 7 is connected to the rotating cylinder 2 by a member 8 interposed between its inner circumferential surface and the outer circumferential surface of the rotating cylinder 2.
Kneading blades 11 are attached at appropriate intervals to the inner peripheral surface of the large-diameter cylinder 7 to form a kneading section 10 and an upper opening 8a thereof. Discharge vanes 12 are attached at appropriate intervals along the outer periphery. Upper opening 8
The annular groove 13 that is externally fitted and covered by the fixed annular upper cover 9a and covers the discharge blade 12 is the hot hopper 1.
4, and a recovery port 15 is provided at an appropriate location on the lower outer periphery of the hot hopper 14. The lower opening 8b of the large-diameter cylinder 7 made of a truncated conical drum is loosely fitted and covered by a fixed lower lid 9b. A charging chute 16 for charging bituminous pavement waste material and a burner 18 are attached to the lower lid body 9b. The input chute 16 has a lower end 17 facing the lower opening of the rotating cylinder 2 and an upper end projecting to the outside of the rotating cylinder 2 and the large diameter cylinder 7. The burner 18 is directed toward the inside of the rotary cylindrical body 2 near the center of the lower lid body 9b, avoiding the lower end 17 of the input chute 16.

According to the present invention having the above configuration, when new aggregate is charged from the new aggregate input chute 6, the rotating cylinder 2 is rotated, and the burner 18 is ignited, the scraping blades 4a and 4b are activated. As the rotating cylindrical body 2 rotates, the new aggregate is scraped up, falls, and stirred, and in the process, it flows toward the lower opening 2c while being heated directly or indirectly by the flame 19 of the burner 18. , also heated to 230-300℃. Here, when the above-mentioned bituminous pavement waste is introduced from the input chute 16 for inputting waste materials, it is stirred and mixed with the new aggregate heated to 230 to 300°C, and is passed through the lower opening 2c of the rotating cylinder 2 into the kneading section. Sent to 10. In this kneading section 10, as the large diameter cylindrical body 7 rotates, the kneaded aggregate is scraped up by the kneading blades 11, falls down, is stirred, and is mixed between the outer circumferential surface of the inclined rotating cylindrical body 2 and the inside of the large diameter cylindrical body 7. It flows in the opposite direction through the space formed by the surrounding surface, and reaches a temperature of 160 to 180°C as a recycled bituminous mixture of new aggregate and bituminous pavement waste, and flows from the opening 8a of the large diameter cylinder 7 to the hot hopper 14. There, it is scraped up by the discharge blades 12 and discharged from the recovery port 15.

The large diameter cylindrical body 7 is not limited to a truncated conical drum, and may be a simple cylindrical drum, but a truncated conical drum is preferable in order to smoothly flow and discharge the bituminous mixture in the opposite direction.

〔Effect of the invention〕

According to the present invention, only the new aggregate is heated in the rotating cylindrical body and discharged to the kneading section, and the paving waste is fed into the kneading section without being heated and mixed with the heated new aggregate. Since the paving waste is not directly heated as in the case of conventional technology, the bitumen is burned and blue smoking containing nitrogen dioxide, sulfur dioxide, aldehydes, etc. is generated. can be completely avoided,
There is no pollution to nearby residents. An upper wall body with an input chute for introducing new aggregate is loosely fitted into the upper opening of the inclined rotating cylinder, and the bituminous pavement waste is directed to the kneading section formed at the lower opening side of the rotating cylinder. Since a charging chute is attached, only new aggregate can be heated and discharged to the kneading section, and at the same time, pavement waste can be directly charged to the kneading section. A large diameter cylindrical body is fitted onto the outer peripheral edge of the slanted lower opening and integrated with the rotating cylindrical body, and kneading blades are attached to the periphery of the large diameter cylindrical body to form a kneading section. Thermal energy at the outer periphery of the cylindrical body can be effectively used to heat the bituminous pavement waste, and at the same time, the heating time can be extended, so that the center of the bituminous pavement waste is heated and the moisture in the waste is reduced. Transpiration is complete. Further, the bitumen in the waste material becomes fluid and transfers to the new aggregate, forming a primary bituminous film on the new aggregate. Furthermore, by adding new bituminous material in the next step, a secondary bituminous film is formed, which greatly contributes to increasing the strength and improving the quality of the recycled bituminous mixture.

Next, by effectively utilizing the outer periphery of the rotating cylinder, there is no need for extra installation space, and the burner is attached to the inside of the rotating cylinder, avoiding the input chute for inputting waste materials. direct heating can be completely avoided.

[Brief explanation of drawings]

They all relate to embodiments of the present invention, and Fig. 1 is a side sectional view of the heating device, Fig. 2 is a front view of the heating device, and Fig. 3 is a front view of the heating device.
The figure is a sectional view taken along the line AA in FIG. 1. DESCRIPTION OF SYMBOLS 1... Heating device, 2... Rotating cylindrical body, 2a... Drum roller, 2b... Upper opening, 2c... Lower opening,
3...Support roller, 4a, 4b...raking blade, 4c...
Check blade, 4... Abutment, 5... Upper wall body, 5a... Circular wall body, 5b... Ring wall, 6... Input chute for new aggregate,
7... Large diameter cylindrical body, 8... Member, 8a... Upper opening, 8
b... Lower opening, 9a... Annular upper lid, 9b... Lower lid, 10... Kneading section, 11... Kneading blade, 12... Discharge blade, 13... Annular groove, 14... Hot hopper,
15... Collection port, 16... Input chute for inputting waste materials,
17...lower end, 18...burner, 19...flame.

Claims (1)

[Claims] 1. The new aggregate heated in the rotating cylinder is discharged into a kneading section provided at the outer periphery of the lower opening of the rotating cylinder, and bituminous pavement waste is introduced into the kneading section. The bituminous material is characterized in that the new aggregate heated by the process is kneaded with the bituminous pavement waste material, and the paving waste material is indirectly heated by heat exchange to be mixed and integrated as an aggregate of a recycled bituminous mixture. How to heat pavement waste. 2. The upper opening of the rotating cylindrical body, which is tilted in the longitudinal direction and can be freely rotated in the circumferential direction by a drive mechanism, is loosely fitted with an upper wall body with an input chute for inputting new aggregate, and the outer periphery of the lower opening is covered. A large-diameter cylindrical body is externally fitted to the rotating cylindrical body, and kneading blades are attached to the circumferential surface of the large-diameter cylindrical body to form a kneading part,
A lower lid is loosely fitted into the lower opening of the large-diameter cylinder, and the lower lid has a charging chute for charging bituminous pavement waste toward the kneading section, and a rotating cylinder that avoids the charging chute. A heating device for bituminous pavement waste characterized by being equipped with a burner directed into the body. 3. The drive mechanism includes a drum roller that is rotated around the outer peripheral surface of a rotating cylindrical body, a support roller that supports the drum roller on a support base and rotates the drum roller by frictional force, and a decelerator and a transmission 3. The bituminous pavement waste heating device according to claim 2, comprising a motor that is rotated via a pulley and an inverter that arbitrarily changes and controls the rotational speed of the motor.