JPS6350485B2 - - Google Patents

Description

[Detailed description of the invention] The present invention provides replacement of existing asphalt pavement,
The present invention relates to a device for recycling asphalt pavement waste materials generated during repair work or construction of equipment buried under existing asphalt pavement.

Generally, large chunks of asphalt pavement waste material (hereinafter referred to as "waste material") dug up during road construction etc. are mechanically crushed using a crusher or the like, or thermally crushed using hot water or high-temperature steam to form asphalt on the surface of the aggregate. The waste materials are made into aggregate particles with a coating, and these waste materials are managed by particle size, and the waste materials of the desired particle size are taken out according to the type of asphalt mixture, and this is put into a heating device or dryer for heating and regeneration. However, when heating waste materials, it is important not to heat the asphalt contained in the waste materials above the deterioration temperature. For this reason, the temperature of the gas fed into the dryer is kept at 500 to 800 degrees Celsius, and in order to prevent the asphalt from overheating, three to four times the amount of air needed for combustion is sucked in to lower the gas temperature.

Furthermore, the temperature of the gas discharged after heat exchange in the dryer is around 200°C, and the gas carries away a large amount of heat, resulting in large heat loss and high fuel consumption.

Therefore, in order to effectively utilize the high-temperature exhaust gas derived from the dryer, it is possible to circulate the exhaust gas into the combustion chamber of the burner, but the exhaust gas contains dust generated when heating the waste material. Since this dust is coated with asphalt which has become sticky due to heating, a cleaning dust collector is usually used as the dust collector. For this reason, the gas that has passed through the cleaning and collecting device has a lower temperature and contains water droplets, so there is no advantage to circulating it.

In view of the above points, the present invention mixes stone powder into a gas flow containing sticky dust derived from a dryer,
The surface of the dust is coated with stone powder to make the dust non-adhesive, and after the dust is captured by a cyclone dust collector, a part of the gas is circulated to the combustion chamber of the dryer, thereby reducing fuel consumption. It is an attempt to save money.

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

Reference numeral 1 denotes a dryer which is a heating device, and is of a rotary kiln type, in which a cylindrical drum 2 having a large number of scraping blades (not shown) arranged around its inner periphery is rotatably supported at an angle. It is rotated at a predetermined speed by a drive device (not shown). 3 is a burner installed at one end of the drum 2, which forms a flame in the combustion chamber 4 and sends high-temperature gas into the drum 2, and an exhaust fan 6 installed at the end of a flue 5 connected to the other end of the drum 2. The combustion gas is sucked into the drum 2.
Asphalt composite material produced by feeders 8a, 8b, 8c equipped with a control device and capable of freely taking out quantitative amounts from hoppers 7a, 7b, 7c that store crushed waste material according to various particle sizes while maintaining a high-temperature gas flow passing through the interior. The waste materials are taken out according to the type, and are fed into the drum 2 via the belt conveyor 9 and the belt conveyor 10, and the waste materials are rolled down in the drum 2 and heated to a desired temperature. The heated waste material is put into a mixer 12 from a discharge section 11, and the missing asphalt is replenished as needed, and a softener and stone powder, which are property restoring agents, are mixed in and adjusted before being shipped.

Reference numeral 13 denotes a stone powder storage bin for storing stone powder, and a blower 15 for pressure feeding the stone powder discharged from a rotary valve 14, which is a quantitative supply device provided at a lower discharge part.
It is then transferred through the supply pipe 16 and fed into the flue 5 connected to the drum 2. Reference numeral 17 denotes a constriction section provided in the flue 5, 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 18 is a cyclone dust collector that captures coarse particles of dust flowing out, and 19 is a bag filter that is a filter dust collector that captures fine particles of dust that are not captured by the cyclone dust collector.

20 is a branch pipe provided in the flue 5 connected to the outlet of the cyclone dust collector 18, which is connected to the combustion chamber 4 via a fan 21, and circulates part of the exhaust gas to the combustion chamber 4. . Reference numeral 22 denotes an air volume adjustment device provided in the flue 5, and 23 represents an air volume adjustment device provided in the branch pipe 20, which is electrically or pneumatically operated and can be opened and closed to adjust the amount of circulating gas.

However, in order to recycle waste materials, hopper 7a,
7b, 7c to feeder 8a, 8b,
8c and conveyor belts 9 and 10.
The waste material is put into the drum 2 through the drum 2, and is heated by combustion gas from the burner 3 while being rolled down while being scraped up by scraping blades provided in the drum 2. The heated waste material is then transferred from the discharge section 11 to the mixer. Put it in 12.
Dust coated with sticky asphalt flows out along with the gas flow passing through the drum 2, but is removed from the stone powder storage bin 13 by the rotary valve 1.
The stone powder discharged in fixed quantities through the pipe 4 is sent to the flue 5 via the supply pipe 16 using a pressure-feeding blower 15.
The stone powder is sent into the interior of the flue 5, and the dust collides with the stone powder near a constriction part 17 provided in the flue 5, so that the stone powder adheres to the asphalt portion on the dust surface, and the dust surface is coated with the stone powder to make the dust non-adhesive. The sticky dust passes through the downstream flue without adhering to it, and the cyclone dust collector 18 collects the coarse part of the dust and most of the stone powder not adhering to the dust. The gas flowing out from the cyclone dust collector 18 is introduced into the bag filter 19, where fine particles of dust and stone powder that was not captured by the cyclone dust collector 18 are collected, and the purified gas is sent to the chimney 24.
The exhaust gas is emitted into the atmosphere, and by adjusting the opening degrees of the air volume regulators 22 and 23 as appropriate, a part of the gas is sucked in by the fan 21 and sent to the combustion chamber 4 through the branch pipe 20, thereby reusing the exhaust gas. Measure.

Incidentally, the dust and stone powder captured by the cyclone dust collector 18 and the bag filter 10 are transferred to the mixer 12.
used after being reduced to

As described above, the present invention mixes stone powder into a gas flow containing sticky dust derived from a dryer that heats waste materials, coats the dust surface with stone powder to make the dust non-stick, and collects this dust in a cyclone. Since a part of the gas captured by the dust device is circulated to the combustion chamber of the dryer, it can be used without lowering the exhaust gas temperature, and has the practical benefit of saving fuel consumption.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the apparatus of the present invention. 1... Dryer, 2... Drum, 3... Burner, 4... Combustion chamber, 5... Flue, 13... Stone powder storage bin, 14... Rotary valve, 15... Blower for pressure feeding, 16... Supply pipe, 17... Throttle section, 18... Cyclone dust collector, 19... Bag filter, 20... Branch pipe, 21... Fan,
22, 23...Air volume adjustment device.

Claims (1)

[Claims] 1. Stone powder is mixed into the gas flow containing sticky dust derived from a dryer, which is a waste material heating device, and the dust surface is coated with stone powder to make the dust non-sticky.
An asphalt pavement waste recycling device characterized in that the dust is captured by a cyclone dust collector and a part of the gas is circulated into the combustion chamber of the dryer.