JPH0478911B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of drying and heating two types of materials with different properties, such as new aggregate and recycled aggregate, under conditions suitable for their properties. This invention relates to a dryer for drying and heating asphalt aggregate.

[Conventional technology]

Conventionally, in asphalt plants, when producing recycled composite material by mixing recycled aggregate with new aggregate,
In order to prevent the asphalt components contained in the recycled aggregate from deteriorating or burning, overheated new aggregate and room temperature recycled aggregate are mixed in a mixer, and the recycled aggregate is heated with the new aggregate. Alternatively, a dryer dedicated to recycled aggregate can be installed in the asphalt plant to heat the recycled aggregate, and this can be mixed with new aggregate heated in another dryer to produce recycled composite material. It has produced.

[Problem to be solved by the invention] However, in the former case, the recycled aggregate cannot be heated as theoretically possible due to restrictions in terms of equipment or thermal efficiency, so the recycled aggregate cannot be heated as expected. There are complaints that the heating and drying of the material tends to be insufficient, and that it is practically impossible to increase the percentage of recycled aggregate mixed in by more than 20%.

In the latter case, although there is no disadvantage as mentioned above, in addition to the dryer for new aggregate, it is necessary to take the trouble to install a dedicated dryer for recycled aggregate, which increases the complexity of the equipment and increases equipment costs. Not only does it increase operating costs, making it uneconomical, but it also tends to mix with asphalt mist in the exhaust, producing blue smoke and bad odors. It also adheres to the filter cloth of the bag filter, damaging it, which limits the dust collection system. There is a problem that occurs.

[Means for solving problems]

The present invention provides an inclined cylindrical rotating drum having a lower manifold at the lower end, an intermediate manifold at the middle, and an upper manifold at the upper end, and a heating device provided in the lower manifold of the inclined cylindrical rotating drum. , the lower end is provided with a discharge chute for recycled aggregate, etc., and a heated gas intake, the discharge chute is disposed in the middle manifold part of the inclined cylindrical rotating drum, and the upper end opening is disposed in the upper manifold part, respectively. A cylinder provided concentrically with the inclined cylindrical rotating drum at the center of the inclined cylindrical rotating drum with a gap formed between the inclined cylindrical rotating drum and the inclined cylindrical rotating drum provided in the upper manifold. a first input means for inputting new aggregate, etc. into the cylinder; a second input means provided in the upper manifold for inputting recycled aggregate etc. into the cylinder; The above-mentioned conventional problem can be solved by providing a dust collector and an exhaust fan connected in series, and a circulation duct equipped with a circulation fan and connected to the combustion chamber of the heating device by connecting the exhaust section for the inner cylinder of the upper manifold. This solves the problem.

[Effect]

The inclined cylindrical rotating drum and the inner cylinder are rotated in the circumferential direction, and while the heating device is feeding heated gas into the inclined cylindrical rotating drum, new aggregate is introduced into the inclined cylindrical rotating drum by the first charging means, and the recycled aggregate is fed into the inclined cylindrical rotating drum. It is charged into the inner cylinder by the second charging means.

The new aggregate placed in the inclined cylindrical rotating drum is
It gradually moves downward through the gap between the inclined cylindrical rotating drum and the inner cylinder, is dried and heated by the heated gas, and is discharged from the lower manifold.

On the other hand, the recycled aggregate introduced into the inner cylinder is dried and heated by heated gas fed into the inner cylinder from the intake port at the lower end, and is discharged from the intermediate manifold.

The heated gas that has worked to dry and heat the new aggregate in the inclined cylindrical rotating drum is sucked in by the exhaust fan and released into the atmosphere from the rotating drum exhaust section of the upper manifold through the exhaust duct and dust collector. In addition, the heated gas that has worked to dry and heat the recycled aggregate in the inner cylinder is sucked by the circulation fan and introduced into the combustion chamber of the heating device through the circulation duct, where it burns the asphalt mist and converts it into new aggregate again. Used for drying and heating recycled aggregate.

In the above case, the heated gas sent into the inner cylinder works to heat the new aggregate in the inclined cylindrical rotating drum and lowers the temperature to an appropriate level before reaching the intake port of the inner cylinder. The asphalt components contained in it will not burn or deteriorate its properties.

The new aggregate dried and heated above and the recycled aggregate are mixed in a mixer or the like to obtain a recycled composite material.

〔Example〕

FIGS. 1 and 2 show an embodiment of the present invention, and in these figures, reference numeral 1 represents an inclined cylindrical rotating drum. This inclined cylindrical rotating drum 1 is supported by a pivot shaft 2 and a jack 3, and a support roller 5 is mounted on a base 4 which is provided to be tiltable up and down with the pivot shaft 2 as a fulcrum.
It is arranged to be placed in an inclined state on the top of the cylinder and rotated in the circumferential direction by a rotary drive device (not shown) in a well-known manner. A lower manifold 6, an intermediate manifold 7, and an upper manifold 8 are respectively provided at the lower end, middle, and upper end of the inclined cylindrical rotating drum 1, and are fixed to the base 4.

A heating device 9 consisting of a burner 9a and a combustion chamber 9b is connected to the lower manifold 6, and an inner cylinder 10 is connected to the inclined cylindrical rotating drum 1 at the center of the upper end side of the inclined cylindrical rotating drum 1. Between〓
It is provided concentrically with the inclined cylindrical rotating drum 1 with a space 11 between the two. This inner cylinder 10 is used to dry and heat recycled aggregate, etc., and has a discharge chute 12 for recycled aggregate, etc. and an intake port 13 for heated gas at its lower end, and the discharge chute 12 is connected to an inclined cylindrical rotating drum 1. The upper end opening 14 is arranged at the inner cylinder exhaust part 8b of the upper manifold 8, and the exhaust chute 1
2 and a rod-shaped support 15 to the inclined cylindrical rotating drum 1.

Further, a damper 17 is provided at the outside air intake port 16 of the intermediate manifold 7 so as to be openable and closable by a hinge 18, and a discharge feeder 19 for discharging recycled aggregate or the like is provided at the lower part of the intermediate manifold 7. Furthermore, at the lower part of the upper manifold 8, a first input means 20 such as a belt conveyor for inputting new aggregate etc. into the inclined cylindrical rotating drum 1, and a first inputting means 20 such as a belt conveyor for inputting new aggregate etc. into the inner cylinder 10 from the upper end opening 14 are provided. A second input means 21 such as a belt conveyor is provided, and an upper rotary drum exhaust section 8a and an inner cylinder exhaust section 8b are provided.
An exhaust duct 22 and a circulation duct 23 are individually provided. A blade 24 is installed in the intake port 13.
are arranged radially and rotate together with the inner cylinder 10 to repel the recycled aggregate to the right in FIG. 1, thereby preventing the recycled aggregate from falling into the inclined cylindrical rotating drum 1.

Incidentally, as is well known, raking blades 25 and 41 are provided on the inner peripheral surfaces of the inclined cylindrical rotating drum 1 and the inner cylinder 10.

26 is a batch tower, which includes a hot elevator 28 that receives the new aggregate discharged from the lower manifold 6 via the feeder 27, a screen 29 that sieves the new aggregate received from the hot elevator 28 according to particle size, and a screen 29. A hot bin 30 for storing the new aggregate sieved by particle size, a weighing hopper 31 disposed below the hot bin 30, a mixer 32 disposed below the weighing hopper 31, and the intermediate manifold 7.
A surge bin 33 receives and stores recycled aggregate discharged from the discharge feeder 19 via a conveyor (not shown), and feeds the recycled aggregate into the weighing hopper 31 as necessary. There is.

The exhaust duct 22 is provided with an opening/closing damper 34, a dust collector 35, and an exhaust fan 36, and the circulation duct 23 is provided with an opening/closing damper 37 and a circulation fan 38.
and a combustion chamber 9b of the heating device 9.
has been contacted. Reference numeral 39 denotes a connecting duct that includes an opening/closing damper 40 and connects the exhaust duct 22 and the circulation duct 23, but this is not necessarily necessary.

Next, the operation of the dryer for drying and heating asphalt aggregate, etc. configured as described above will be explained.

The inclined cylindrical rotary drum 1 and the inner cylinder 10 are rotated in the circumferential direction, the exhaust fan 36 and the circulation fan 38 are operated, and the heating device 9 is operated to feed heated gas into the inclined cylindrical rotary drum 1, while new bone is removed. The material is charged into the inclined cylindrical rotating drum 1 by the first charging means 20, and the recycled aggregate is charged into the inner cylinder 10 by the second charging means 21.

The new aggregate placed in the inclined cylindrical rotating drum 1 is placed between the inclined cylindrical rotating drum 1 and the inner cylinder 10.
It moves to the lower end of the inclined cylindrical rotating drum 1 through the space 11 and is discharged from the lower manifold 6.
During this time, the inside of the inclined cylindrical rotary drum 1 is dry-heated countercurrently by heating gas moving from left to right in FIG. In addition, the recycled aggregate placed in the inner cylinder 10 passes between the blades 24 at the intake port 13 and is heated by the heated gas introduced into the inner cylinder 10 as shown in FIG. It gradually moves to the left and is discharged from the discharge chute 12 to the discharge feeder 19 of the intermediate manifold 7. The new aggregate discharged from the lower manifold 6 is transferred to the feeder 27.
and the screen 29 via the hot elevator 28
There, they are classified according to particle size and stored in a hot bin 30. Furthermore, the recycled aggregate discharged to the discharge feeder 19 is stored in a surge bin 33. The new aggregate and recycled aggregate stored in the hot bin 30 and surge bin 33 are weighed by a weighing hopper 31 and put into a mixer 32, where they are mixed at a desired blending ratio to form a recycled composite material.

The heated gas used to dry and heat the new aggregate in the inclined cylindrical rotating drum 1 is cleaned by removing dust and the like in a dust collector 35, and then is discharged to the atmosphere through an exhaust fan 36. Also, from the intake port 13 to the inner cylinder 1
The exhaust gas containing a large amount of asphalt mist that has entered the chamber and worked to dry and heat the recycled aggregate is sucked by the circulation fan 38 and circulated through the circulation duct 23 to the combustion chamber 9b of the heating device 9. The asphalt mist is burned and reused for drying and heating new and recycled aggregates. In addition, if the amount of asphalt mist contained in the exhaust gas from heating the recycled aggregate is small, the circulation fan 38 is stopped.
While closing the opening/closing damper 37, the opening/closing damper 4
By opening 0, the exhaust gas used for drying and heating the recycled aggregate is transferred from the connecting duct 39 to the exhaust duct 2.
2, the dust is sent to the dust collector 35 and released into the atmosphere.

In the above, the temperature of the heated gas introduced into the inner cylinder 10 from the intake port 13 is a temperature at which the asphalt component in the recycled aggregate does not deteriorate or burn, i.e., about 500°C, and this temperature is normally adjusted. ,
Operate the heating device 9, dampers 17, 34, 3
This is done by adjusting the opening of the valves 7 and 39, adjusting the exhaust fan 36, and changing the amount of new aggregate added. The recycled aggregate is transferred from the surge bin 33 to a dedicated weighing hopper (not shown).
Alternatively, the water may be introduced into the mixer 32 via a .
In addition, when the recycled aggregate is not dried and heated by this dryer, a part of the new aggregate, especially the fine particles that are easily heated, may be poured into the inner cylinder 10, or only the inclined cylindrical rotating drum 1 can be used without using the inner cylinder 10. Dry and heat the new aggregate using

〔Effect of the invention〕

As explained above, the dryer for drying and heating asphalt aggregate, etc. according to the present invention has an inner cylinder provided in the inclined cylindrical rotating drum, and works to dry and heat the new aggregate to appropriately lower the temperature. Since it is configured to dry and heat the recycled aggregate with gas, the recycled aggregate can be efficiently and sufficiently dried and heated without degrading or burning the asphalt components. In addition, it is easy to increase the mixing ratio of recycled aggregate to new aggregate, there is no need for a dryer specifically for recycled aggregate, and there is no need for high equipment or operating costs. , economical. On top of that,
A circulation duct equipped with a circulation fan is provided to connect the exhaust part for the inner cylinder of the upper manifold and the combustion chamber of the heating device, and the heating gas used for drying and heating the recycled aggregate in the inner cylinder is transferred to the heating device. Since the asphalt mist contained therein is returned to the combustion chamber and burned, it is possible not only to prevent problems such as blue smoke and bad odor caused by asphalt mist, but also to improve thermal efficiency.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a dryer for drying and heating asphalt aggregate, etc. according to the present invention, and FIG. 2 is a cross-sectional view of the portion shown in FIG. 1. DESCRIPTION OF SYMBOLS 1... Inclined cylindrical rotating drum, 6... Lower manifold, 7... Intermediate manifold, 8... Upper manifold, 8a... Exhaust part for rotating drum, 8b... Exhaust part for inner cylinder, 9... Heating device, 9b... Combustion chamber, 10... Inner cylinder, 11... Between, 12... Discharge chute, 13... Intake, 14... Upper end opening, 20... First input means, 21... Second input means, 22... Exhaust duct, 2
3...Circulation duct, 35...dust collector, 36...exhaust fan,
38... Circulation fan.

Claims (1)

[Claims] 1. An inclined cylindrical rotating drum having a lower manifold at the lower end, an intermediate manifold at the middle, and an upper manifold at the upper end, a heating device provided in the lower manifold of the inclined cylindrical rotating drum, and the lower end. is provided with a discharge chute for recycled aggregate, etc. and an intake port for heated gas, the discharge chute is disposed in the middle manifold part of the inclined cylindrical rotating drum, and the upper end opening is disposed in the upper manifold part, respectively. An inner cylinder is provided concentrically with the inclined cylindrical rotating drum at the center of the inclined cylindrical rotating drum, with a gap formed between the inner cylinder and the inclined cylindrical rotating drum. a first input means for inputting aggregates, etc.; a second input means provided in the upper manifold for inputting recycled aggregates etc. into the inner cylinder; An asphalt aggregate characterized by comprising a dust collector and an exhaust fan that are connected in series, and a circulation duct that is equipped with a circulation fan and that connects the exhaust section for the inner cylinder of the upper manifold to the combustion chamber of the heating device. Dryers for drying and heating, etc.