JPS60230408A - Method for preventing adhesion of sticky dust generated at time of regeneration of asphalt pavement waste material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for regenerating asphalt pavement waste generated from existing asphalt pavement, b) replacement and repair of pavement, and further construction of equipment buried under existing asphalt pavement;
In particular, it is intended to prevent sticky dust that flows out along with the combustion gas flow during the heating process from adhering to the downstream flue inner wall, etc.

Asphalt pavement waste dug up during road construction (
The lumps (hereinafter referred to as "waste materials") are pulverized by a mechanical crushing method using a cracker, etc., or by a thermal crushing method in which the waste materials are immersed in hot water or high-temperature steam and then mechanically stirred to break the bonds. The material is made into granular aggregate particles with an asphalt coating on the surface, and is fed to a dryer, which is a heating device, to soften the asphalt and restore its properties, thereby recycling the waste material.

Normally, a dryer that heats waste materials consists of a rotatable, inclined cylindrical drum, and the waste materials are fed into the drum and transferred and flowed down along the inclination direction, while combustion gas is supplied into the drum by a burner. The waste materials are heated.

However, when using this method, fine particles in the waste material become dust and flow out along with the gas flow. This dust is attached to asphalt, which becomes sticky when heated, and therefore adheres to the inner wall of the downstream flue, especially the curved pipe section, and if this is repeated, it will block the flue. Induces a decline in equipment capacity and functionality. In addition, because the dust that flows out is sticky, bag filters, which are filtration and dust collection devices that use fiber filter media, cannot be used, and cleaning dust collection devices are mainly used. The performance is also poor, and the current situation is that it cannot be said to be desirable from the standpoint of pollution prevention.

In view of the above points, the present invention mixes stone powder into the gas flow flowing out from the dryer, causes the stone powder to adhere to the asphalt that covers the dust accompanying the gas flow, and coats the surface of the dust with the stone powder to prevent the dust from being removed. By making it sticky, it prevents dust from adhering.

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

1 is a dryer which is a heating device, and is of a rotary kiln type, and has a large number of raking blades (not shown) on the inner periphery.
A cylindrical drum 2 surrounding the drum is rotatably supported at an angle,
It is rotated at a predetermined speed by a drive device (not shown). Reference numeral 3 denotes a burner installed at one end of the drum 2, which sends combustion gas into the drum 2, and sucks the combustion gas with an exhaust fan 5 installed at the end of a flue 4 connected to the other end, causing high-temperature gas to pass through the drum 2. While maintaining the gas flow, feeders 7a, 7 are equipped with a control device and can freely take out fixed quantities from hoppers 6a, 6b, 6C that store crushed waste material according to various particle sizes.
The waste materials are taken out according to the type of asphalt mixture to be produced in step 7C and fed into the drum 2 via the belt conveyor 8.9, and the waste materials are transferred and flowed down within the drum 2 and heated to a desired temperature. The heated waste material is dumped from the discharge section 10 into a mixer 11, and the missing asphalt is replenished as necessary, and a softener and stone powder, which are property restoring agents, are mixed in and adjusted before being shipped.

12 is a stone powder storage bin for storing stone powder, and the stone powder is discharged from a rotary valve 13, which is a quantitative supply device provided at a lower discharge part, and is passed through a supply pipe 1 using a pressure-feeding blower 14.
5 and fed into the flue 4 connected to the drum 2. Reference numeral 16 denotes a constriction section provided in the flue 4, which narrows the cross-sectional area through which the gas flow passes, so that the stone powder can efficiently adhere to the dust. Reference numeral 17 is a cyclone dust collector that captures coarse particles of dust flowing out, and 18 is a bag filter (3) that is a filtering dust collector that captures fine particles of dust that are not captured by the cyclone dust collector. It is. 19 is a chimney.

Therefore, in order to recycle waste materials, the hoppers 6a, 6b, 6
According to the type of asphalt mixture to be produced from step c, waste materials of a desired particle size are taken out by feeders 7a, 7b, and 7C, and fed into the drum 2 via a belt conveyor 8.9.
While scraping up the waste material with scraping blades provided in the drum 2 and transferring it down, it is heated with combustion gas from a burner 3, and the heated waste material is fed into a mixer 11 from a discharge section 10. Dust coated with sticky asphalt flows out along with the gas flow passing through the drum 2, but the stone powder is discharged in fixed quantities from the stone powder storage bin 12 via the rotary valve 13, and the blower 14 is used to force-feed the stone powder. Supply Vibrator 1
5 into the flue 4, the stone powder collides with the dust near the constriction part 16 provided in the flue 4, the stone powder adheres to the asphalt on the dust surface, the dust surface is coated with the stone powder, and the dust is be non-adhesive. The dust that has become non-adhesive passes through the downstream flue 4 without adhering to it, and the coarse dust particles are collected by the cyclone dust collector 17 and the fine dust particles are collected by the bag filter 18. At the same time, the stone powder not attached to the dust is also collected, and the purified gas is released into the atmosphere from the chimney 19.

Since the stone powder used to cover the dust is mixed in to restore the properties of the asphalt mixture, the dust and stone powder captured by the cyclone dust collector 17 and the bag filter 18 are returned to the mixer 11. There is no waste if you use it properly.

As described above, the present invention mixes stone powder into the gas stream introduced from the dryer, and coats the sticky dust accompanying the gas stream with the stone powder to make the dust non-sticky. It is useful for pollution prevention because it prevents it from adhering to downstream dust collectors, etc., without causing a decline in the capacity or function of the equipment, and also allows the use of bag filters with high dust collection performance that use fiber filter media. It is.

Furthermore, since the stone powder used to coat the dust surface is originally mixed into the asphalt mixture, the dust captured by the cyclone dust collector and bag filter (6) is mixed into the recycled asphalt mixture. Since it can be used as is, there is no waste.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of a recycled asphalt pavement waste blunt using the method of the present invention. l...Dryer? ...Drum 3...Eighth 4
... Flue duct 12 ... Stone powder storage bin 13 ... Rotary valve 14 ... Pressure feeding proa 15 ... Supply vibrator 16 ... Squeezing section 17 ... Cyclone dust collector 18 ... Bug Filter - Patent Applicant Nikko Co., Ltd. Procedural Amendment (Act 0) August 21, 1980 Patent Application No. 87586 2, Name of Invention Adhesion of sticky dust generated during recycling of asphalt pavement waste materials Prevention method 3: Relationship with the case of the person making the amendment Patent applicant

Claims (1)

[Claims] A method for preventing the adhesion of sticky dust generated during the recycling of asphalt pavement waste material, characterized by mixing stone powder into the gas stream discharged from a dryer, which is a device for heating the asphalt pavement waste material.