JPH03147903A - Dryer for asphalt plant - Google Patents

Abstract

PURPOSE:To make it possible to get rid of odor at a low cost by recirculating gas containing malodorous components conducted from the side of a cold-hopper into a combustion chamber through a circulation flue when new aggregate and scrap wood are heated at a time. CONSTITUTION:A discharge gate 17 is operated to open, and hot air is sent to the inside of a drum 3 while making flames in a combustion chamber 8 by means of an aggregate heating burner 7. After that, new aggregate is supplied to a shoot 15 through a conveyor 29, and it is thrown into the drum 3 from a through-hole 12 of the drum 3. Then, the new aggregate is heated up to a required temperature while rolling it down to the inside of the top half of the drum 3, and it is discharged from a discharge port 9 of the lower part of a hot-hopper 6. Scrap wood is supplied to the last half of the drum 3 from the side of a cold-hopper 20 through a conveyor 30, and it is heated and dropped from a through-hole 13 to discharge through the discharge gate 17. In addition, the exhaust gas generated inside the drum 3 is sucked and exhausted by a blower 22 provided to a circulation flue 21, and it is recirculated into the combustion chamber 8 after dust is removed by a dust collector 23.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a dryer that is an aggregate heating device for an asphalt plant that manufactures asphalt mixture, which is a road paving material. It concerns a dryer that can also heat materials.

[Prior art] Asphalt pavement waste material (hereinafter referred to as "waste material J") dug up during road construction, etc. is being heated and recycled using a dryer, which is a heating device, and reused as asphalt mixture. Dryers for heating waste materials are often installed together with dryers for heating new aggregate in asphal plants. Therefore, in order to save space, etc., the applicant has developed a method for heating both new aggregate and waste materials in a single drum. We have filed a patent application for a dryer for asphalt plants that can be used in asphalt plants (Japanese Patent Application No. 147117/1983).

[Problem to be solved by the invention] In recent years, when waste materials containing asphalt are heated, a bad odor is generated depending on the heating conditions, and this bad odor may be radiated into the neighborhood. Therefore, from an environmental conservation perspective, countermeasures against the bad odor have been developed. has become necessary.

Therefore, in view of the above points, the present invention aims to improve the previously applied dryer for asphalt plants and propose a dryer for asphalt plants that can deodorize at low cost without using large deodorizing equipment. It is something that can be done.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a hot hopper having a burner and a combustion chamber at one end, and a cold hopper having a circulation flue at the other end. A partition plate is used to partition the drum, which is tilted and pivoted so that it can rotate once, with a partition plate.
A cylindrical body that separates and passes hot air is inserted into the front half of the drum near the burner, and its tip is passed through the partition plate. Two rows of through holes are drilled for material input and waste material discharge, the through holes are surrounded from the outer periphery by a cover body, and a new aggregate input part is placed on the upper part of the cover body located on the burner side, and a hot hopper is installed. A new aggregate discharge port is provided at the bottom, and a waste material supply section that can also supply new aggregate to the cold hopper is provided, and a waste material discharge port with a discharge gate is provided at the bottom of the cover body located on the cold hopper side. Furthermore, there is provided a dryer for an asphalt plant, characterized in that one end of the circulation flue of the cold hopper is connected to the combustion chamber with an exhaust fan interposed in the middle, and a discharge flue is provided in the cover body. It is something to do.

[Function] In the dryer for an asphalt plant according to the present invention, the entire amount of exhaust gas led out from the cold hopper side of the drum, which heats and regenerates new aggregate in the first half and waste material in the second half, is distributed to the hot hopper side. The exhaust gas is returned to the combustion chamber where it was installed, and the exhaust gas is combusted in the combustion chamber, decomposing it into carbon dioxide gas and water vapor, and making it odorless. The high-temperature exhaust gas reheated in the combustion chamber is then sent into the drum again, heating new aggregate in the front half of the drum and heating waste material in the rear half. At this time, out of the total amount of gas in the drum, the amount of gas that gradually increases due to the combustion air taken in from the burner, the air that enters from the drum gap, and the steam generated from the heated waste material is arranged in the cover body from near the center of the drum. It is released from the emission flue.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 is a dryer for heating new aggregates and waste materials, and is a cylindrical drum 3 with a large number of scraping blades 2 arranged around it.
is tilted and rotatably supported by support rollers 5 on a machine stand 4, and is rotated at a predetermined speed by a drive device (not shown). 6 is a hot hopper disposed at one end of the drum 3, a burner 7 is disposed on the hot hopper 6 side, and a combustion chamber 8 for forming a flame is provided in front of the burner 7. Further, a new aggregate discharge port 9 is formed at the bottom of the hot hopper 6 to discharge heated new aggregate.

A partition plate 10 is fixed inside the drum 3 near the center to partition the inside of the drum, and a cylinder of an appropriate diameter is installed in the front half of the drum 3 near the burner 7 to guide a part of the hot air to the rear half of the drum 3. A shaped body 11 is inserted, and its tip end is passed through the partition plate IO.

A through hole 12 for introducing new aggregate and a through hole 13 for discharging waste material are bored at appropriate intervals in the drum solid wall sandwiching the partition plate IO.
The through holes 12 and 13 are surrounded by a cover body 14 which is fixed and separated from the drum 3 from the outer periphery.

Reference numeral 15 denotes a new aggregate inputting chute arranged on the upper part of the cover body 14, and its tip passes through the cover body 14 and faces the new aggregate inputting hole ■2 drilled in the drum 3. New aggregate is introduced into the drum 3 through the through holes 12, and a guide chute 16 is attached to each through hole 12 so that the new aggregate can be smoothly introduced into the drum 3.

A waste material discharge port 17 is provided at the bottom of the cover body I4, faces the waste material discharge hole 13 formed in the drum 3, and is provided with a discharge gate 8. By opening and closing the discharge gate 18, the material flowing down the rear half of the drum is allowed to fall through the waste material discharge hole 13 and is discharged to the outside. Also, by closing the discharge gate 18, a part of the material flowing down the rear half of the drum is removed from the waste material discharge port 17.
While accumulating the aggregate, the material can be fed laterally through the cover body 14 toward the burner side using the feed blade 19, and then scraped up by the guide chute 16 and transferred from the new aggregate injection hole 12 to the front half of the drum. It looks like this.

A cold hopper 20 is disposed at the other end of the drum 3. A circulation flue 21 is connected to the cold hopper 20 for discharging the exhaust gas from the drum 3. An exhaust fan 22 for sucking and exhausting exhaust gas led out from the drum 3 and a dust collector 23 for collecting scattered dust in the exhaust gas are provided. The other end of the circulation flue 21 is connected to the combustion chamber 8 , and the exhaust gas discharged from the drum 3 is guided to the combustion chamber 8 . 24 is a discharge flue connected to the cover body 14, and a blower (not shown) at the end of the discharge flue 24 discharges the exhaust gas passing through the gap between the cylindrical body 11 and the front half of the drum. It is discharged into the atmosphere via a dust collector (not shown). A shielding plate 25 is attached to the burner 7 side of the cylindrical body 11 to maintain the flame properly, and may be attached as appropriate as necessary. Reference numerals 26, 27, and 28 denote flow rate adjusting dampers, which are arranged to adjust the flow rate of exhaust gas passing through each flue.

29 is a conveyor for supplying new aggregate, and is designed to supply new aggregate cut out from an aggregate hopper (not shown) to the chute 15 for introducing new aggregate. Reference numeral 30 denotes a conveyor that supplies both waste material and new aggregate, and supplies material cut from a waste material hopper (not shown) and the aggregate hopper to the rear half of the drum from the cold hopper side.

When the waste material is heated simultaneously with new aggregate, the discharge gate 17 at the bottom of the cover body 14 located near the center of the drum on the cold hopper 20 side is opened, and the burner 7 for heating the aggregate is heated into the combustion chamber 8. Drum 3 while forming a flame with
While sending hot air into the interior, new aggregates of various particle sizes are supplied by the conveyor 29 to the chute 15 for introducing new aggregates near the center of the drum 3, and the through hole for introducing new aggregates drilled in the drum 3 is 12 into the drum 3, the new aggregate is heated to a desired temperature while flowing down the front half of the drum 3, and is discharged from the new aggregate discharge 9 at the bottom of the hot hopper 6. In addition, the waste material is transferred to a cold hopper 20 by a conveyor 30.
It is supplied to the rear half of the drum 3 from the side. Then, the high-temperature hot air passed through the cylindrical body 1 inserted into the front half of the drum 3 and was guided to the rear half of the drum, heating the rear half of the drum to a desired temperature while flowing down. The waste material is dropped through a waste material discharge hole 13 drilled near the center of the cover body 14, and is discharged from a waste material discharge port 17 at the bottom of the cover body 14. At this time, the exhaust gas accompanied by odor, blue smoke, and dust generated in the drum 3 is sucked and exhausted by the exhaust fan 22, the dust is removed by the dust collector 23 installed in the middle of the circulation flue 21, and is returned to the combustion chamber 8. Ru. The exhaust gas returned to the combustion chamber 8 is heated to a high temperature by the flame of the burner 7, and the odor components and blue smoke in the exhaust gas are thermally decomposed and become odorless. The deodorized high-temperature exhaust gas is sent into the drum 3 again and reused to heat the waste material. Due to the circulation of the exhaust gas, the amount of air required for the burner 7, the amount of air entering from each seal part of the drum 3, and the amount of gas commensurate with the water vapor generated as the waste material and aggregates are heated become surplus gas and gradually increase. However, these surplus gases are discharged to the outside from a discharge flue 24 connected to the cover body 14 near the center of the drum 3. Furthermore, in order to circulate the entire amount of exhaust gas in this way, it is preferable to use the minimum amount of air necessary for combustion in the burner.

[Effects of the Invention] As described above, according to the dryer for an asphalt plant according to the present invention, when new aggregate and waste materials are heated simultaneously, the exhaust gas containing odor components and blue smoke derived from the cold hopper 20 Ill. is returned to the combustion chamber 8 through the circulation flue 21 and circulated within the drum 3, so that the odor components and blue smoke in the exhaust gas discharged from the drum 3 are thermally decomposed in the combustion chamber 8 to deodorize the exhaust gas. This makes it possible to prevent as much as possible the harm to the surrounding environment due to unpleasant odors.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinally sectional schematic front view of an embodiment of a dryer for an asphalt plant according to the present invention, FIG. 2 is a partially omitted sectional view taken along line A-A in FIG. Partially omitted B
-B sectional view. l...Dryer 3...Drum 6...Hot hopper 7...Burner 8...-Combustion chamber 9...New aggregate discharge port 1, 0...Partition plate 11...Cylindrical body 1
2...Through hole for new aggregate input 13...Through hole for waste material discharge 14...Cover body 15...-New aggregate input chute 17...Waste material discharge port 18...Discharge gate
20...Cold hopper...-Circulation flue 2...Exhaust fan 24...-Discharge flue 29...Conveyor 30...-Conveyor

Claims (1)

[Claims] A hot hopper with a burner and a combustion chamber at one end and a cold hopper with a circulation flue at the other end are arranged, and the approximately central part of the drum is rotatably supported at an angle and is partitioned off with a partition plate. A cylindrical body that separates and passes hot air is inserted into the front half of the drum near the burner, and its tip is inserted through the partition plate, and new aggregate is inserted at appropriate intervals along the peripheral wall of the drum that sandwiches the partition plate. Two rows of through holes are drilled for input and waste material discharge, the through holes are surrounded from the outer periphery by a cover body, and a new aggregate input section is placed at the upper part of the cover body located on the burner side, and at the bottom of the hot hopper. A new aggregate discharge port is provided in the cold hopper, and a waste material supply section that can also supply new aggregate to the cold hopper is provided.A waste material discharge port with a discharge gate is provided in the lower part of the cover body located on the cold hopper side. A dryer for an asphalt plant, wherein one end of the circulation flue of the cold hopper is connected to the combustion chamber with an exhaust fan interposed therebetween, and a discharge flue is provided in the cover body.