JP2001271308A - Recycle plant for asphalt waste material and method of operating recycle drier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recycle plant, by which an asphalt mixture can be obtained by removing smoke and an odor component by the operation of only a recycle drier and which is operated easily. SOLUTION: The surface moisture of the waste material A is removed in a half drying type recycle drier 21a, and an exhaust gas generated in the recycle drier 21a is forwarded into a dust collector 12, moisture in the waste material A is removed in a full drying type recycle drier 21b, and the exhaust gas generated in the recycle drier 21b is returned to a combustion furnace 11 supplying the recycle driers 21, 21b with hot air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recycling plant for reclaiming asphalt waste generated by repairing and repairing existing asphalt pavement roads and road works.

[0002]

2. Description of the Related Art Asphalt-paved roads are susceptible to cracks and ruts due to long-term use. As a repair method, conventional methods include overlaying paving asphalt on existing pavement. The so-called replacing method is used to excavate.

[0003] A so-called recycling plant is used in order to effectively use asphalt pavement waste (hereinafter referred to as waste) of an asphalt-paved road excavated by such a replacement method or road construction. This recycling plant recycles waste materials excavated by road construction into aggregate particles with asphalt coating on the aggregate surface by mechanical crushing with a crusher or thermal disintegration with hot water or high-temperature steam. It can be reused by drying by heating with a dryer.

[0004] Such a method of regenerating waste materials includes a normal temperature charging method in which normal temperature waste materials are charged and mixed with a heated new asphalt new material (hereinafter referred to as "new material"), or the waste materials are heated to about 150 ° C. There is a heating charging method in which the mixing ratio of waste materials to new materials is increased by heating and mixing.

However, when the waste material is heated to 150 ° C. or more, the effective asphalt component in the waste material is degraded, and blue smoke is generated due to over-combustion. As disclosed in JP-A-7-252805, waste materials are heated to 60 to 100 ° C. to evaporate moisture in the waste materials (half dry method), and then mixed with the heated new materials to regenerate asphalt mixture. Methods have also been used.

As a result, the generation of blue smoke can be suppressed, and the amount of exhaust gas containing smoke and odor components generated in a conventional recycling plant and affecting the environmental protection of the surroundings can be reduced. Was made possible.

As another invention for treating the exhaust gas, for example, Japanese Patent Application Laid-Open No. 10-131114 discloses
There is disclosed a recycling plant in which a new material dryer for heating new aggregate and a recycle dryer for heating waste material are provided, and a combustion chamber and a deodorizing furnace are provided in the new material dryer.

In this recycling plant, hot air is sent from the combustion chamber to a recycling dryer, and the waste material is heated and regenerated by the hot air, and the exhaust gas generated by the recycling dryer is returned to the combustion chamber of the new material dryer provided therewith, and the odor in the exhaust gas is returned. The components are burned to perform a deodorizing treatment.

[0009]

With these recycling plants, it is possible to remove odor components, smoke and the like generated when heating waste materials. However, JP
According to the recycling plant described in JP-A-131114, which has a structure in which smoke and odor components generated by the recycle dryer return to the combustion chamber of the new material dryer, the new material dryer and the recycle dryer must be operated together.
It requires driving time and extra heat. In addition, in the conventional heating-input type recycling plant, when the mixing ratio of the waste material exceeds 50% of the new material, there is a problem that the deodorizing effect is weakened.

[0010] It is an object of the present invention to obtain an asphalt mixture by operating only a recycling dryer without operating a new material dryer, and to remove smoke and odor components by operating only such a recycling dryer. It is possible to provide a recycling plant that can be easily operated without using an excess amount of heat.

[0011]

In order to solve the above-mentioned problems, an asphalt waste material recycling plant according to the present invention comprises a first recycled dryer and a second recycled dryer having different degrees of drying, and a first and a second recycled dryer. It is characterized in that one hot air generator for supplying hot air to the two recycle dryers is provided, or a combustion device is provided for each of the first and second recycle dryers. With this configuration, the waste material from which surface water has been removed by heating the waste material to the extent that the asphalt does not dissolve in the first recycled dryer is further heated to a higher temperature in the second recycled dryer. Asphalt mix recycled only by heating and drying can be shipped.

[0012] The first recycle dryer and the second recycle dryer may be provided separately from each other.
It is also possible to connect and connect the outlet side of the recycling dryer and the entrance side of the second recycling dryer. In the case of disposing them individually, the existing recycle dryer may be used as the first recycle dryer or the second recycle dryer, and only one dryer and a hot air generator or a combustion device may be separately added. Furthermore, if each recycle dryer is installed in the upper and lower tiers, no new installation space is required on the ground, so that horizontal space saving can be realized.

When the outlet side of the first recycled dryer and the inlet side of the second recycled dryer are connected to each other, a transport device for sending waste material from the first recycled dryer to the second recycled dryer is provided. No need to install. Further, since no installation space for each recycle dryer is required upward, space saving in the vertical direction can be realized.

Further, when the exhaust gas generated in the first recycling dryer is exhausted by the exhaust means and the exhaust gas generated in the second recycling plant is returned to the hot air generator, the odor component generated in the first recycling dryer is removed. Exhaust gas containing almost no amount can be easily removed.
Exhaust gas containing an odor component generated by a recycle dryer can be deodorized by oxidative decomposition with a hot air generator, and can be reused as hot air.

By heating the first and second recycle dryers from the outside by the hot air from the hot air generator, the inside of the dryer and the external drum can be heated simultaneously, so that the waste material can be heated more efficiently.

The method of operating a recycled dryer according to the present invention is characterized in that the asphalt waste material is surface-dried by low-temperature heating in the first recycled dryer, and the asphalt waste material after surface drying is heated to high temperature in the second recycled dryer and internally dried. Exhaust gas generated by the first recycle dryer is removed by exhaust means, and the exhaust gas generated by the second recycle dryer is returned to the hot air generator for supplying hot air to the first and second recycle dryers. According to this method, the asphalt mixture regenerated only by heating and drying with a recycling dryer can be shipped, and the exhaust gas generated in the first recycling dryer can be easily removed. The generated exhaust gas can be reused.

Here, the heating temperature of the waste material in the first recycle dryer is preferably in the range of 40 to 100 ° C., and the heating temperature of the waste material in the second recycle dryer is one.
A range from 20 to 180 ° C is preferred. By setting the temperature in such a range, the first recycle dryer can remove the surface moisture of the waste material, and the second recycle dryer can effectively remove the moisture inside the waste material.

[0018]

(Embodiment 1) FIG. 1 is a diagram showing an apparatus configuration of a recycling plant according to the present invention.

A lump of waste material excavated by asphalt pavement renovation work, road construction, or the like is subjected to mechanical crushing with a crusher or the like, or thermal crushing with hot water or high-temperature steam to form a bone having an asphalt coating on the surface of the aggregate. These waste materials are managed by particle size, and waste material A having a desired particle size is taken out according to the type of asphalt mixture.

The waste material A transported into the recycling plant 1 is supplied to the waste material cold bin 2 and then transported to the recycling device 4 by the belt conveyor 3a and the transport device 3b. The recycle device 4 includes a first recycle dryer 21a, a second recycle dryer 21b, and a combustion furnace 11 for supplying hot air to each dryer.

Waste material A transported into the recycling plant
Is a first recycle dryer 21 of a half-dry system.
a and the second recycle dryer 21b of the full dry system
And is stored in the heated waste material storage bin 6 by the skip transport device 5. This is put into a measuring and conveying device 7 provided below the heated waste material storage bin 6 and then conveyed by a measuring and conveying device 7 through a chute 8 into a mixer 10 for mixing with new material.

On the other hand, a new material B is transferred by a transfer device (not shown).
Is supplied into the new material dryer 13, the new material B is heated to about 180 to 200 ° C. in the new material dryer 13. The heated new material B is transferred from the hot elevator 14 to the vibrating sieve 15
Into the hot bin 16 via the.

The crushed stone of the new material B put into the hot bin 16, the dried waste material transported by the measuring and transporting device 7, and the asphalt heated to about 150 ° C. are rotationally mixed by the openable mixer 10. Asphalt mixture using recycled material of waste material A can be manufactured.

FIG. 2 is a flow chart showing the structure and operation flow of the recycling apparatus according to the first embodiment.
Shows a state where the inside of the dryer is heated, and (b) shows a state where the inside of the dryer and the external drum are heated. In the figure, the solid arrows indicate the flow of waste material, the broken arrows indicate the flow of hot air and exhaust gas, and the dashed line indicates the external drum. In this embodiment, two dryers are individually arranged.

In the recycling apparatus 4, the waste material A is heated by sending hot air to the first recycle dryer 21a and the second recycle dryer 21b by the combustion furnace 11.

The first recycle dryer 21a includes:
A so-called half-dry recycle dryer that heats the asphalt contained in the waste material A without dissolving the asphalt contained therein by heating the waste material A at a low temperature of 40 to 100 ° C. The recycle dryer 21b dissolves the asphalt component in the waste material by heating the waste material A to a high temperature of 100 to 180 ° C.
This is a so-called full-dry type recycle dryer for removing water contained in the waste material A.

The waste material A conveyed from the cold bin 2 by the belt conveyor 3 is charged into the recycle dryer 21a through the charging port 20a. Since the supplied waste material A is heated to about 80 ° C. in the dryer, the surface moisture can be reduced from about 3% to about 1%. At the same time, from the waste material A, an exhaust gas of about 100 ° C. containing almost no smoke or odor components is generated.

This exhaust gas is discharged together with water vapor into an exhaust portion 22a.
After being subjected to detoxification processing such as filter purification in the dust collecting device 12a, the air is discharged to the outside through the chimney 18 by the exhaust fan 17.

Further, the waste material A from which the surface moisture has been removed is conveyed from the discharge port 23a by the belt conveyor 19 shown in FIG. 1, and is supplied to the input port 20b of the recycle dryer 21b. Since the input waste material A is heated to about 160 ° C. in the dryer, the asphalt component in the waste material A is dissolved, and the water content is reduced to 0.5% or less. At the same time, a small amount of about 180 ° C. exhaust gas containing smoke and odor components is generated from the waste material A.

The exhaust gas is exhausted by the fan 25 to the exhaust section 2.
When returning to the combustion furnace 11 via 2b, it is deodorized by oxidative decomposition in the combustion furnace 11, and is sent again to each dryer as hot air. With such a configuration, only exhaust gas generated by half-drying that can be easily rendered harmless is discharged, and exhaust gas generated by full-drying can be repeatedly used as hot air.

The waste material dried by the recycle dryer 21b is transported from the outlet by the skip transport device 5, and
When the raw material B is put into the measuring device 9 according to the following procedure, the new material B and asphalt are rotationally mixed in the mixer 10 by the above-described operation to obtain a desired asphalt mixture.

The recycle dryers 21a and 21b
When hot air of about 700 ° C. for heating the inside is generated by the combustion of the burner 28 formed in the combustion furnace 11, the fans 24, 25
And a blower pipe (not shown) and a blower port 2 which are sucked in each dryer direction and communicate with each recycle dryer.
It is supplied to the inside of the dryer via 7a and 27b. The amount of hot air blown into the dryer can be adjusted by the fans 24 and 25, and the amount of combustion of the burner 28 can be adjusted according to the total required heat of each dryer.

Here, the recycle dryers 21a, 21a
hot air for heating b and the recycle dryer 21a,
The flow of the exhaust gas generated in 21b will be described.

The required amount of hot air generated in the combustion furnace 11 is adjusted by fans 24 and 25, respectively, and is sent to each dryer to be used for heating waste materials. Next, the exhaust gas generated by the recycle dryer 21a is exhausted to the dust collector 12 by the fan 24 together with the hot air. At this time, since the inside of the recycle dryer 21a has a negative pressure, the hot air generated in the combustion furnace 11 is sucked into the interior of the recycle dryer 21a by the fan 24. Also,
The exhaust gas generated by the recycle dryer 21b is exhausted into the combustion furnace 11 by the fan 25 together with the hot air. At this time, since the inside of the recycle dryer 21b has a negative pressure, the hot air generated in the combustion furnace 11 by the fan 25 is
It is sucked into the recycle dryer 21b. By repeating this, the exhaust gas sent to the recycle dryer 21b can be reused as hot air, and the hot air used for the recycle dryers 21a and 21b can be supplied only by operating the fans 24 and 25, respectively. Thus, the structure can be simplified.

When heating the first and second recycle dryers 21a and 21b, an air duct (not shown) communicating with not only the interior of the dryer but also the external drums 29a and 29b of the recycle dryers 21a and 21b, respectively. Is formed and hot air is supplied, so that the external drums 29a, 2
9b can also be heated. Thereby, the time for heating the inside of the dryer can be reduced, and the waste material A can be more efficiently heated. At this time, the external drum 29
a, 29b are heated by the exhaust fan 26, respectively.
When collected by the fan 24 and the exhaust gas collected by the fan 24, it is sent into the dust collecting device 12a.

The first and second recycle dryers 2
If the 1a21b is arranged in two upper and lower stages, it is not necessary to provide a new installation space on the ground, and a planar space saving can be realized.

(Embodiment 2) FIG. 3 is a flow chart showing a structure and a flow of operation of a recycling apparatus according to a second embodiment.
(B) shows a state in which the inside of the dryer and the external drum are heated. In the figure, the solid arrow indicates the flow of the waste material A, the broken arrow indicates the flow of the hot air and the exhaust gas, and the dashed line indicates the external drum. Further, this embodiment is different from the first recycling dryer 31a in the outlet side and the second recycling dryer 31b.
Are connected to each other.

In this embodiment, the discharge port 23a and the input port 20b of the first embodiment are connected. For this reason, the waste material A can be directly sent from the first recycled dryer 31a to the second recycled dryer 31b without providing the belt conveyor 19 for transporting the waste material A.

Further, an exhaust portion 32a for exhausting exhaust gas substantially free of smoke and odor components generated in the first recycle dryer 31a, a blower port 37b for blowing hot air into the second recycle dryer 31b, and a suction port for exhaust gas. The configuration and operation of the device other than the fan 34 are similar to those of the first embodiment.

By adopting such a structure, the belt conveyor 19 for transporting the waste material A from the first recycle dryer 31a to the second recycle dryer 31b is not required, and labor and cost for performing extra work are reduced. Make it possible.

The recycle dryers 31a and 32a
The hot air that heats the inside is generated by the combustion of a burner 38 provided in the combustion furnace 11, is blown by a fan 34, and is supplied to the inside by blower tubes (not shown) and blower ports 37 a and 37 b leading to respective recycle dryers. You. The amount of hot air blown into the dryer is
The amount of combustion of the burner 38 can be adjusted according to the total required heat of each dryer.

Here, the recycle dryers 31a, 31
b and the hot air for heating b and the recycling dryer 31a,
The flow of the exhaust gas generated in 31b will be described.

The hot air generated in the combustion furnace 11 is adjusted in air volume by fans 34 and 35 by a required amount in the same manner as in the first embodiment, and is sent to each dryer. Further, the exhaust gas generated by the recycle dryers 31a and 31b is:
Since the inside of the recycle dryers 31a and 31b becomes negative pressure because the air is sucked by the fans 34 and 35, respectively, the hot air generated in the combustion furnace 11 is cooled by the fans 34 and 35, respectively.
Is sucked into the recycle dryers 31a and 31b. By repeating this, supply of hot air and exhaust of exhaust gas can be performed only by operating the fans 34 and 35.

When heating the first and second recycle dryers 31a and 31b, not only the hot air is blown into the interior but also the recycle dryers 31a and 31b, respectively.
By forming a blower tube (not shown) communicating with the external drums 39a and 39b of 1b and supplying hot air, the waste material A can be heated more efficiently. At this time, the external drum 39a,
The hot air heating 39b is supplied to fans 36a and 36, respectively.
When collected by b, it is sent to the dust collecting device 12a together with the exhaust gas collected by the fan 34a and is discharged to the outside.

The first and second recycle dryers 2
Since the installation space for 1a and 21b is not required above, space saving in the vertical direction can be realized.

(Embodiment 3) FIG. 4 is a flow chart showing the structure and operation flow of a recycling apparatus according to a third embodiment. FIG. 4 (a) shows a first recycling dryer and a second recycling dryer separately. (B) shows a state in which the outlet side of the first recycle dryer and the inlet side of the second recycle dryer are connected and arranged. In the figure, solid arrows indicate the flow of waste material A, and broken arrows indicate the flow of hot air and exhaust gas.

In the present embodiment, the burners 48a and 4b are respectively provided to the first recycle dryer 41a and the second recycle dryer 41b without providing the combustion furnace 11 shown in FIG.
The burner 48a, 48b controls the supply of combustion for the required amount of heat.

The configuration of the apparatus is the same as that of FIG. 2 (a) except for the method of treating the exhaust gas generated from the second recycle dryer 41b.
And FIG. 3 (a).
Exhaust gas generated from a, 41b is fan 45,
It is sucked by 46 and sent to the inside of the dust collecting device 12a after performing processes such as detoxification.

With such a structure, it is not necessary to form a combustion furnace and a blower tube communicating from the combustion furnace to a recycle dryer, so that space saving of the apparatus can be achieved. In addition, since the amount of heat of the recycle dryers 41a and 41b is adjusted by the respective burners 48a and 48b, the amount of heat can be easily managed. Further, since no heat loss occurs in the blower tube or the like until the hot air reaches the recycle dryer from the combustion furnace, the amount of heat burned can be maximized.

When the recycling plants of the above three embodiments are used, the exhaust gas generated from the waste material is converted into the exhaust gas generated by the half-dry type recycle dryer.
Since it can be collected in a state containing almost no smoke and odor components, it can be easily purified and can be discharged without adversely affecting the environment. Further, since the amount of exhaust gas containing smoke and odor components generated by the full-dry type recycle dryer is small, it can be easily deodorized.

In addition, since the exhaust gas generated from the waste material is exhausted only by the recycle dryer and the hot air generator, the recycle dryer can be operated without operating the new material dryer. , 100
% Waste can be shipped as recycled asphalt mix.

[0052]

According to the present invention, the following effects can be obtained.

(1) Either a first recycle dryer and a second recycle dryer having different degrees of drying are provided, and one hot air generator for supplying hot air to the first and second recycle dryers is provided, or By providing the first and second recycle dryers with the respective combustion devices, the first recycle dryer heats the waste material to such an extent that the asphalt does not dissolve the asphalt, and removes the waste material from the surface in the second recycle dryer. Further, by heating to a high temperature to remove the water inside, 100% waste material regenerated by a recycle dryer can be shipped.

(2) In the case where the first and second recycle dryers are individually provided, only one recycle dryer and a hot air generator may be additionally provided in addition to the existing recycle dryer. By installing each recycle dryer in two upper and lower stages, space saving in the horizontal direction can be realized. Further, when the outlet side of the first recycle dryer and the inlet side of the second recycle dryer are connected to be disposed, a transport device for sending waste material from the first recycle dryer to the second recycle dryer becomes unnecessary. . In addition, since the installation space for each recycle dryer is not required upward, space saving in the vertical direction can be realized.

(3) The exhaust gas generated in the first recycling dryer is discharged by the exhaust means, and the exhaust gas generated in the second recycling plant is returned to the hot air generator to generate the exhaust gas generated in the first recycling dryer. The exhaust gas containing almost no odor component can be easily removed, and the exhaust gas containing the odor component generated by the second recycle dryer can be deodorized by the hot air generator, and can be reused as hot air.

(4) By hot air from the hot air generator,
By heating the first and second recycled dryers from the outside, the inside of the dryer and the external drum can be heated simultaneously, so that the waste material can be heated more efficiently.

(5) The waste material is heated to 40 to 100 ° C. by the first recycle dryer, and the waste material is heated to 120 to 180 ° C. by the second recycle dryer. Can be removed, and the water inside the waste material can be removed by the second recycling dryer.
The asphalt mixture can be regenerated only with a recycle dryer without using a new material dryer.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing the arrangement and configuration of a device of a recycling plant of the present invention.

FIGS. 2A and 2B are flow charts showing a structure and a flow of an operation of a recycling apparatus according to the first embodiment, wherein FIG. 2A shows a state in which the inside of a dryer is heated, and FIG. Is shown.

FIG. 3 is a flowchart showing a structure and a flow of an operation of a recycling apparatus according to a second embodiment, wherein (a) shows a state where the inside of a dryer is heated, and (b) shows a state where the inside of the dryer and an external drum are heated. Is shown.

FIG. 4 is a flowchart showing the structure and operation flow of a recycling apparatus according to a third embodiment, where (a) shows a state in which a first-stage recycle dryer and a second-stage recycle dryer are separately arranged, b) shows a state in which the outlet side of the recycle dryer in the first step is connected to the inlet side of the recycle dryer in the second step.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Recycling plant 2 Cold bin 3a, 19 Belt conveyor 3b Transport device 4 Recycling device 5 Skip transport device 6 Heated waste material storage bin 7 Metering transport device 8 Chute 9 Meter 10 Mixer 11 Combustion furnace 11a Pipe 12a, 12b Dust collector 13 New Material dryer 14 Hot elevator 15 Vibrating sieve 16 Storage hopper 16 Hot bin 17 Air exhaust 18 Chimney 20a, 20b Input ports 21a, 21b, 31a, 31b, 41a, 41b Recycle dryer 22a, 22b, 32a Exhaust parts 23a, 23b Discharge ports 24 , 25, 26a, 26b, 35, 36a, 36b,
45,46 fan 27a, 27b, 37a, 37b blower port 28,38,48a, 48b burner 29a, 29b, 39a, 39b external drum

Claims (7)

[Claims] An apparatus for recycling asphalt waste material, comprising a first recycle dryer and a second recycle dryer having different degrees of drying, and a single hot air generator for supplying hot air to the first and second recycle dryers. An asphalt waste recycling plant comprising a device or a combustion device in each of the first and second recycle dryers. 2. The asphalt waste recycling plant according to claim 1, wherein said first and second recycle dryers are individually provided. 3. The asphalt waste material recycling plant according to claim 1, wherein an outlet of the first recycle dryer is connected to an inlet of the second recycle dryer. 4. The exhaust gas generated by the first recycle dryer is exhausted by exhaust means, and the exhaust gas generated by the second recycle dryer is returned to the hot air generator. The asphalt waste recycling plant described. 5. The hot air from the hot air generator generates:
The asphalt waste material recycling plant according to claim 1, wherein the first and second recycle dryers are externally heated. 6. In an asphalt waste material recycling plant, asphalt waste material is surface-dried by low-temperature heating in a first recycle dryer, and asphalt waste material after surface drying is heated to high temperature in a second recycle dryer and internally dried. The exhaust gas generated by the first recycle dryer is removed by an exhaust unit, and the exhaust gas generated by the second recycle dryer is returned to a hot air generator that supplies hot air to the first and second recycle dryers. Operating method of recycling dryer. 7. The first recycled dryer heats asphalt waste material to 40 to 100 ° C., and the second recycled dryer heats asphalt waste material to 120 to 18 ° C.
The method for operating a recycled dryer according to claim 6, wherein the method is heated to 0 ° C.