JPS6129766Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for reducing dust collected from a dust collector in an asphalt plant.

Conventionally, in asphalt plants, the dust scattered from the dryer is collected by a dust collector such as a cyclone and returned to the hot elevator, and then sent to the plant body along with the heated aggregate that has passed through the dryer, where it is mixed into asphalt mixture as sand equivalent. It is used. The reduced dust accounts for approximately 5% by weight of the entire heated aggregate, and approximately 1.0% by weight for sand with a particle size of 25m/m or less, but recently the thermal efficiency of dryers has been improved from the perspective of energy conservation. As a result, the temperature of the exhaust gas discharged from the dryer tends to decrease, so that the temperature of the dust carried away by the exhaust gas stream also decreases. However, aggregate temperature control in a dryer involves detecting the temperature of heated aggregate discharged from the dryer using an aggregate temperature detection sensor installed in the discharge chute of a hot hopper installed on the aggregate discharge side of the dryer.
Since the burner combustion amount is controlled by comparing the desired aggregate temperature (approximately 170℃) set in advance and using a control signal according to the comparison, the aggregate temperature including the dust collected by the dust collector can be controlled. If the recovered low-temperature dust is used in asphalt mixture as equivalent to sand, it will lower the temperature of the mixture below the desired temperature, which will interfere with the temperature control of the asphalt mixture being manufactured, and will cause problems in quality control. This has led to undesirable results.

In view of the above points, the present invention is configured to return the dust collected by the dust collector to the hot hopper on the discharge side of the dryer, thereby making it possible to control the temperature of the aggregate including the collected dust, thereby improving quality. The purpose is to manufacture high-quality asphalt composite material.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The asphalt plant is composed of a dryer 1, a plant main body 2, a dust collector 3, and the like. The dryer 1 is of a rotary kiln type, in which a cylindrical rotary cylinder 4 is tilted and supported on a base so that it can freely rotate around its long axis, and is rotated at a predetermined speed by a drive device (not shown). Inside the rotary cylinder 4, there are provided around the rotating cylinder 4 a feeding blade for feeding the aggregate into the interior, a rake blade for lifting the aggregate and dropping it onto the curtain, and a discharge blade for discharging the aggregate. A cold hopper 5 is provided on the aggregate supply side of the rotating cylinder 4, and a hot hopper 6 is provided on the aggregate discharge side.The aggregate conveyed by the conveying device 7 is fed into the cold hopper 5 side of the dryer 1, and While rolling and flowing down the tube 4, it is heated and dried by the burner 8, reaches the cold hopper 6, is discharged from the hot hopper 6 by a discharge blade provided at the tip of the rotary tube 4, flows down the discharge chute 9,
It is supplied to the plant main body 2 by a hot elevator 10. Further, an exhaust flue 11 is connected to the cold hopper 5 of the dryer 1, and dust scattered from the dryer 1 is collected by a dust collector 3 provided in the middle of the exhaust flue 11. A discharge chute 12 is provided at the bottom of the dust collector 3, and the end of this discharge chute penetrates the wall of the hot hopper 6 of the dryer 1 to return the collected dust to the hot hopper 6. Reference numeral 13 denotes an aggregate temperature detection sensor for detecting the temperature of the heated aggregate discharged from the dryer 1, and the combustion amount of the burner 8 is controlled by the output of this aggregate temperature detection sensor 13. The plant main body 2 includes a hot bin 14 with a vibrating sieve,
A stone powder storage tank 16 that stores stone powder supplied from a stone powder elevator 15, an aggregate measuring tank 17 that measures and discharges a predetermined amount, a stone powder measuring tank 18, an asphalt measuring tank 19, and mixes the weighed aggregate, stone powder, and asphalt. It is formed by a mixer 20 or the like.

Therefore, the dust generated when the aggregate is heated and dried in the dryer 1 is collected by the dust collector 3 and returned to the hot hopper 6 provided on the discharge side of the dryer 1 via the discharge chute 12, and is discharged from the rotary cylinder 4. The aggregate is forcibly discharged from the hot hopper 6 while being mixed with the heated aggregate by a discharge blade provided at the side tip, and flows down the discharge chute 9 to the hot elevator 10.
Since it is sent to the plant main body 2, the discharge chute 9
The temperature of the heated aggregate including dust is detected by the aggregate temperature detection sensor (1) 13 installed in the The combustion amount of 8 is controlled.

Although the dust collector 3 in FIG. 1 shows a cyclone type primary dust collector, fine dust collected by a filter cloth dust collector (not shown), which is a secondary dust collector, may also be returned to the hot hopper 6. Further, as the dust reducing means, a conveying means such as a screw conveyor may be used instead of the discharge chute 12.

As described above, the present invention transfers the dust collected by the dust collector 3 to the hot hopper 6 on the discharge side of the dryer 1.
Since the temperature of the heated aggregate including dust is detected by the aggregate temperature detection sensor 13 installed in the discharge chute 9 of the dryer 1 and the combustion amount of the burner 8 is controlled, the temperature of the heated aggregate including dust is reduced. Since the temperature of the material can be controlled, the temperature of the asphalt composite material manufactured can be accurately controlled, and quality control can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted schematic side view of an embodiment of the present invention. 1... Dryer, 2... Plant body, 3...
Dust collector, 6... Hot hopper, 8... Burner, 9
...Discharge chute, 12... Discharge chute, 13
...Aggregate temperature detection sensor.

Claims (1)

[Scope of utility model registration request] A dust reduction device for an asphalt plant, characterized in that a discharge part of a dust collector that collects dust scattered from a dryer that heats and dries aggregates is connected to a hot hopper provided on the aggregate discharge side of the dryer.