JP2006207226A - Asphalt recycling plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an asphalt recycling plant which can prevent the occurrence of fires by preventing the vaporized asphalt content in the exhaust from being adhered within a flue. <P>SOLUTION: A deodorization furnace 11 is arranged in the downstream of the exhaust flue 7 of a dryer 1, and heat exchangers 14, 15 are arranged which recover exhaust gas heat from the deodorization furnace 11. Then the asphalt content is decomposed and eliminated by passing through the deodorization furnace 11 and the heat exchangers 14, 15, and the temperature of the hot air supplied to the interior of the dryer 1 is adjusted by circulating part of the exhaust of which the temperature has dropped to the combustion chamber 5 of the dryer 1 by way of an exhaust circulating duct 17. Then part of the hot gas in the deodorization furnace 11 is introduced to the exhaust flue 7, which is in the downstream of the dryer 1, by way of a hot gas reducing duct 22. Then the exhaust gas temperature within the exhaust flue 7 is raised, thus the vaporized asphalt content in the exhaust is prevented from condensing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an asphalt recycle plant that heats and recycles asphalt pavement waste material generated by road construction and the like.

An asphalt recycle plant that heats and recycles asphalt pavement waste (hereinafter referred to as “waste material”) has a dryer for heating waste that has a burner and a combustion chamber at one end. The waste material is heated by supplying it into the dryer, and part of the exhaust gas is returned to the combustion chamber via the exhaust gas circulation duct branched from the exhaust flue of the dryer so that the temperature of the hot air supplied from the burner is lowered. Adjust to avoid overheating the waste. In addition, when the waste material is heated with a dryer, the asphalt component adhering to the waste material is vaporized and the exhaust gas with odor flows downstream. Thus, deodorization is performed (see Patent Document 1).
Japanese Utility Model Publication No. 6-82109

  However, since the exhaust gas temperature exhausted from the dryer is about 200 ° C., the vaporized asphalt content in the exhaust gas is further reduced in the vicinity of the inner wall of the flue and condensed, and the asphalt content is exhausted to the exhaust gas circulation duct and deodorization furnace. It will adhere to the inner wall of the flue. And, if the exhaust gas becomes temporarily high temperature, it may ignite, and if a fire is flying, it may ignite and cause a fire.

  This invention makes it a subject to provide the asphalt recycle plant which prevented generation | occurrence | production of a fire by preventing the vaporized asphalt part in waste gas from adhering in a flue in view of said point.

  In order to solve the above-mentioned problems, the present invention provides an asphalt recycle plant according to claim 1, wherein an odor in exhaust gas is provided downstream of an exhaust flue of a dryer provided with a burner for heating asphalt pavement waste and a combustion chamber. A deodorization furnace for thermally decomposing the components is disposed, a heat exchanger for recovering the exhaust gas heat of the deodorization furnace is disposed, and further, a part of the exhaust gas that has passed through the heat exchanger is burned by the circulation fan by the circulation fan. An exhaust gas circulation duct that circulates in the chamber is provided.

  Further, in the asphalt recycle plant according to claim 2, an opening adjustment damper is disposed in the exhaust gas circulation duct, and the combustion chamber temperature detected by a combustion chamber temperature detector disposed in the combustion chamber is used. The opening adjustment control of the opening adjustment damper is performed.

  In the asphalt recycle plant according to claim 3, a deodorization furnace for thermally decomposing odorous components in the exhaust gas is disposed downstream of the exhaust flue of the dryer that heats the asphalt pavement waste material. It is characterized in that a hot gas reduction duct for guiding a part of the discharged hot gas into the exhaust flue at the outlet of the dryer is provided.

  Further, in the asphalt recycle plant according to claim 4, the exhaust gas detected by an exhaust gas temperature detector disposed in the exhaust flue at the outlet of the dryer, wherein an opening adjusting damper is disposed in the high-temperature gas reduction duct. The opening adjustment control of the opening adjustment damper is performed based on the temperature.

  According to the asphalt recycle plant of claim 1 of the present invention, a burner for heating asphalt pavement waste and a deodorizing furnace for thermally decomposing odor components in the exhaust gas are disposed downstream of the exhaust flue of the dryer having a combustion chamber. In addition, a heat exchanger that recovers the exhaust gas heat of the deodorization furnace is disposed, and an exhaust gas circulation duct that circulates a part of the exhaust gas that has passed through the heat exchanger to the combustion chamber of the dryer by a circulation fan is disposed. As a result, the exhaust gas circulating to the combustion chamber is decomposed and removed through the deodorizing furnace, so that the asphalt component does not adhere to the exhaust gas circulation duct and fire can be prevented.

  According to the asphalt recycle plant of claim 2 of the present invention, the damper for adjusting the opening degree is disposed in the exhaust gas circulation duct, and based on the combustion chamber temperature detected by the combustion chamber temperature detector disposed in the combustion chamber. Since the opening adjustment control of the opening adjusting damper is performed, the temperature of the combustion chamber can be controlled so that the hot air temperature supplied to the dryer can be a temperature suitable for heating the waste material, and the waste material is heated excessively There is no deterioration.

  According to the asphalt recycle plant of claim 3 of the present invention, a deodorizing furnace for thermally decomposing odorous components in the exhaust gas is disposed downstream of the exhaust flue of the dryer that heats the asphalt pavement waste material. Since a high-temperature gas reduction duct is installed to guide a part of the discharged hot gas into the exhaust flue at the outlet of the dryer, the exhaust gas temperature in the exhaust flue downstream of the dryer can be increased and the vaporized asphalt in the exhaust gas is condensed. This makes it difficult to prevent the occurrence of a fire by suppressing the attachment of asphalt to the exhaust flue.

  According to the asphalt recycle plant of claim 4 of the present invention, the exhaust gas detected by the exhaust gas temperature detector disposed in the exhaust flue at the outlet of the dryer, the damper for adjusting the opening degree being disposed in the hot gas reduction duct. Since the opening adjustment control of the opening adjustment damper is performed based on the temperature, the exhaust gas temperature in the exhaust flue can be controlled and maintained at a gas temperature that is difficult to condense asphalt, and the asphalt adhering to the exhaust flue Can suppress the occurrence of fire.

  In the asphalt recycle plant according to claim 1 of the present invention, a deodorizing furnace for thermally decomposing odor components in the exhaust gas is disposed downstream of the exhaust flue of the dryer having a burner and a combustion chamber for heating the asphalt pavement waste material. In addition, a heat exchanger for recovering high-temperature exhaust gas heat is disposed downstream of the deodorization furnace. Further, an exhaust gas circulation duct and a circulation fan are provided for circulating a part of the exhaust gas that has passed through the heat exchanger to the combustion chamber of the dryer. Then, the exhaust gas of about 400 ° C. that has passed through the deodorizing furnace and the heat exchanger is supplied to the combustion chamber of the dryer through the exhaust gas circulation duct, mixed with hot air of about 1800 ° C. sent from the burner to the combustion chamber, and sent into the dryer. The temperature of the hot air is lowered to about 800 ° C. This temperature-adjusted hot air is sent into the dryer and heated to regenerate without deteriorating the waste material.

  As described above, since the exhaust gas at about 400 ° C. that has passed through the deodorization furnace and the heat exchanger is circulated to the combustion chamber of the dryer via the exhaust gas circulation duct, the temperature of the hot air fed into the dryer is adjusted. Can be adjusted to a temperature atmosphere suitable for waste material heating, and the exhaust gas circulating to the combustion chamber is decomposed and removed through the deodorizing furnace, so that the asphalt component does not adhere to the exhaust gas circulation duct and fire. Can be prevented.

  In the asphalt recycle plant according to claim 2 of the present invention, an opening adjustment damper is disposed in the exhaust gas circulation duct, and a combustion chamber temperature detector is disposed in the combustion chamber. Then, the combustion chamber temperature detected by the combustion chamber temperature detector is taken into a damper opening adjuster, compared with a reference temperature preset by the damper opening adjuster, and the opening based on the difference value amount. Opening adjustment control of the damper for adjustment is performed. Thus, the temperature of the hot air supplied to the dryer by controlling the temperature in the combustion chamber is set to a temperature suitable for heating the waste material, and the waste material is not excessively heated and deteriorated.

  In the asphalt recycle plant according to claim 3 of the present invention, a deodorizing furnace for thermally decomposing odorous components in the exhaust gas is disposed downstream of the exhaust flue of the dryer that heats the asphalt pavement waste material. A part of the exhausted hot gas of about 750 ° C. is led into the exhaust flue at the outlet of the dryer through the hot gas reduction duct. As a result, if the exhaust gas of about 200 ° C. exhausted from the dryer and the high temperature gas of about 750 ° C. are combined so that the exhaust gas of about 350 ° C. flows in the exhaust flue downstream of the dryer, the vaporized asphalt in the exhaust gas It becomes difficult to condense, and it is possible to prevent the occurrence of fire by suppressing the attachment of asphalt to the exhaust flue.

  In the asphalt recycle plant according to claim 4 of the present invention, an opening adjustment damper is disposed in the high-temperature gas reduction duct, and an exhaust gas temperature detector is disposed in the exhaust flue at the outlet of the dryer. Yes. Then, the exhaust gas temperature detected by the exhaust gas temperature detector is taken into the damper opening adjuster, compared with a reference value preset by the damper opening adjuster, and based on the difference value, the opening adjustment Perform damper opening adjustment control. As a result, the temperature of the exhaust gas in the exhaust flue is controlled so that the vaporized asphalt content in the exhaust gas does not condense, and the occurrence of a fire can be prevented by suppressing the attachment of the asphalt content to the exhaust flue.

  An embodiment of the present invention will be described below with reference to FIG.

  1 in the figure is a known dryer for heating waste materials, and a cylindrical drum 2 having a large number of scraping blades (not shown) around its inner periphery is inclined on a machine base 3 in a freely rotatable manner. It is supported and rotated at a predetermined speed by a driving device (not shown). A burner 4 is disposed on one end of the drum 2, and hot air is sent into the drum 2 while a flame of the burner 4 is formed in the combustion chamber 5, and connected to a discharge hopper 6 at the other end of the drum 2. The exhaust gas is sucked by the exhaust fan 8 interposed downstream of the exhaust flue 7 to maintain the high-temperature gas flow passing through the drum 2, while the waste material discharged from the aggregate hopper (not shown) is drummed via the belt conveyor 9. The waste material is heated to a desired temperature while rolling down the drum 2.

  A dust collector 10 that captures dust in the exhaust gas is disposed downstream of the exhaust flue 7, and a deodorization furnace 11 for combusting and decomposing asphalt contained in the exhaust gas is disposed downstream of the dust collector 10. Has been established. The exhaust gas that has passed through the deodorizing furnace 11 becomes a clean gas and is discharged from the chimney 12 into the atmosphere.

  The deodorizing furnace 11 is provided with a burner 13 for maintaining the furnace temperature at a predetermined value at one end, exposing the exhaust gas introduced into the furnace to a high-temperature atmosphere, and combusting and decomposing asphalt contained in the exhaust gas. Yes. The deodorization furnace 11 controls the combustion amount of the burner 13 so that the temperature inside the furnace is maintained at a high temperature of, for example, about 750 ° C. or more so that the asphalt can be completely burned and decomposed, and the exhaust gas passes through the furnace. It is preferable to have a staying chamber 11a that takes at least 1 to 2 seconds or more.

  Reference numerals 14 and 15 denote heat exchangers for effectively using the exhaust gas heat held by the exhaust gas having a high temperature of about 750 ° C. discharged from the deodorizing furnace 11, and the heat exchanger 14 is provided with exhaust smoke. The exhaust gas introduced into the deodorizing furnace 11 from the road 7 is heated, and the heat exchanger 15 preheats the combustion air supplied from the combustion air supply fan 16 to the burner 13 of the deodorizing furnace 11. is there.

  Reference numeral 17 denotes an exhaust gas circulation duct that circulates a part of the exhaust gas at about 400 ° C. that has passed through the heat exchangers 14 and 15 to the combustion chamber 5 of the dryer 1, and a circulation fan 18 is interposed in the exhaust gas circulation duct 17. In addition, an air volume adjusting damper 19 is provided upstream of the circulation fan 18. Then, the detected value of the combustion chamber temperature detector 20 disposed in the combustion chamber 5 is taken into the damper opening adjuster 21 and compared with a reference value set in advance by the damper opening adjuster 21, and the difference value amount Based on the above, the opening degree control of the air volume adjusting damper 19 is performed.

  Thus, when heating the waste material, first, the waste material is supplied to the dryer 1 via the belt conveyor 9 and exposed to the hot air from the burner 4 to heat the waste material to a predetermined temperature. At this time, the combustion amount control of the burner 4 is controlled so that the temperature of the heated waste material discharged from the drum 2 or the exhaust gas temperature becomes a preset value. Further, since the hot air temperature fed from the burner 4 is about 1800 ° C., the exhaust air of about 400 ° C. is circulated through the combustion chamber 5 from the exhaust gas circulation duct 17 by the circulation fan 18 and mixed, and the hot air temperature fed into the drum 2 is 800 Adjust the temperature to about ℃ or lower.

  The amount of exhaust gas circulated by the circulation fan 18 is adjusted by appropriately adjusting the opening degree of the air volume adjusting damper 19. At this time, in the case equipped with the damper opening adjuster 21, the hot air temperature in the combustion chamber 5 detected by the combustion chamber temperature detector 20 is taken into the damper opening adjuster 21, and the damper opening adjuster 21 receives it. Then, the combustion chamber temperature is compared with a preset reference value, for example, 800 ° C., and the opening degree of the air volume adjusting damper 19 is controlled based on the amount of the difference value. Make the temperature suitable for heating waste materials.

  Then, the exhaust gas derived from the dryer 2 is guided to the dust collector 10, and dust in the exhaust gas is captured by the dust collector 10, while the exhaust gas that has passed through the dust collector 10 is guided to the deodorizing furnace 11 and is about 750 ° C. in the furnace. The asphalt remaining in the exhaust gas is completely burned and decomposed by exposure to a high temperature atmosphere. The high-temperature exhaust gas discharged from the deodorizing furnace 11 is lowered to about 400 ° C. through the heat exchangers 14 and 15, and as described above, a part of the exhaust gas whose temperature has decreased passes through the exhaust gas circulation duct 17 by the circulation fan 18. Then, it is used after being circulated in the combustion chamber 5.

  In this way, as the temperature of the hot air sent to the dryer 1 is adjusted, the exhaust gas decomposed and removed from the asphalt is circulated through the deodorizing furnace 11, so that the asphalt does not adhere to the exhaust gas circulation duct 17 and fires. Can be prevented.

  FIG. 2 shows another embodiment of the present invention. In FIG. 2, the same reference numerals as those in FIG.

  As shown in FIG. 2, a high temperature gas reduction duct 22 for guiding the high temperature gas discharged from the deodorizing furnace 11 to the exhaust flue 7 at the outlet of the dryer 1 is provided. The high-temperature gas reduction duct 22 is provided with an air volume adjusting damper 23, and the exhaust flue 7 near the outlet of the dryer 1 is provided with an exhaust gas temperature detector 24. Further, a damper opening adjuster 25 for taking in the detection value of the exhaust gas temperature detector 24 is arranged, and the exhaust gas detection value taken in by the damper opening adjuster 25 is compared with a preset reference value, and the difference The opening adjustment control of the air volume adjusting damper 23 is performed based on the value amount.

  When the waste material is heated, the opening degree of the air volume adjusting damper 23 is appropriately adjusted, and a high temperature gas of about 750 ° C. discharged from the deodorizing furnace 11 is discharged through the high temperature gas reduction duct 22 to the exhaust flue 7 at the outlet of the dryer 1. Then, it is combined with an exhaust gas of about 200 ° C. discharged from the dryer 1. At this time, in the case where the damper opening adjuster 25 is provided, the exhaust gas temperature in the exhaust flue 7 detected by the gas temperature detector 24 is taken into the damper opening adjuster 25, and a preset reference value, for example, 350 ° C. And the opening degree of the air volume adjusting damper 23 is controlled based on the difference value, and the temperature in the exhaust flue 7 downstream of the dryer 1 is maintained at about 350 ° C.

  Thus, if the exhaust gas temperature in the exhaust flue 7 is set to a high temperature of about 350 ° C. by introducing the high temperature gas discharged from the deodorizing furnace 11 into the exhaust flue 7 downstream of the dryer 1, vaporization in the exhaust gas is performed. Asphalt is less likely to condense, and asphalt can be prevented from adhering to the exhaust flue 7 to prevent fire.

It is a schematic explanatory drawing which shows one Example of the asphalt recycle plant which concerns on this invention. It is a schematic explanatory drawing which shows the other Example of the asphalt recycle plant which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Dryer 4 ... Burner 7 ... Exhaust flue 8 ... Dust collector 10 ... Dust collector 11 ... Deodorizing furnace 14, 15 ... Heat exchanger 17 ... Exhaust gas circulation duct 18 ... Circulation fan 19 ... Air volume adjustment damper 20 ... Combustion chamber temperature Detector 21 ... Damper opening adjuster 22 ... High temperature gas reduction duct 23 ... Air volume adjusting damper 24 ... Exhaust gas temperature detector 25 ... Damper opening adjuster

Claims (4)

  A heat exchanger for recovering the exhaust gas heat of the deodorizing furnace and disposing a deodorizing furnace for thermally decomposing odorous components in the exhaust gas downstream of the exhaust flue of the dryer having a burner and a combustion chamber for heating the asphalt pavement waste And an exhaust gas circulation duct that circulates a part of the exhaust gas that has passed through the heat exchanger to the combustion chamber of the dryer by a circulation fan.   An opening adjustment damper is disposed in the exhaust gas circulation duct, and the opening adjustment control of the opening adjustment damper is performed based on the combustion chamber temperature detected by the combustion chamber temperature detector disposed in the combustion chamber. The asphalt recycle plant according to claim 1, characterized in that:   A deodorizing furnace for thermally decomposing odor components in the exhaust gas is disposed downstream of the exhaust flue of the dryer that heats the asphalt pavement waste material, and a part of the high-temperature gas discharged from the deodorizing furnace is disposed in the exhaust flue at the outlet of the dryer An asphalt recycle plant characterized by a high-temperature gas reduction duct leading to   An opening adjustment damper is disposed in the hot gas reduction duct, and the opening adjustment control of the opening adjustment damper is performed based on the exhaust gas temperature detected by the exhaust gas temperature detector disposed in the exhaust flue at the outlet of the dryer. The asphalt recycle plant according to claim 3, wherein:

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