JPH0232005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dry dust collector used in an asphalt recycling plant that heats and dries recycled aggregate.

[Conventional technology]

As a dust collection device for an asphalt recycling plant, the applicant of the present invention first provided a dust hopper in a bag filter connected to the exhaust box of a dryer drum, and collected non-adhesive particles from the dust hopper prior to operation of the dryer drum. We have developed a bag filter that forms an initial layer of non-adhesive dust on the surface of the filter cloth by feeding the dust into the bag filter, thereby preventing the filter cloth from clogging with highly adhesive dust including asphalt mist. Publication No. 59-225720).

[Problem to be solved by the invention]

However, in the above-mentioned dust collector for an asphalt recycling plant, it is necessary to bring in the entire amount of non-adhesive dust from another system, which is not rational, and when using the dust collected by the bag filter, the collected dust There is a problem that a dedicated transfer system must be provided and the overall structure tends to become complicated.

The present invention makes it possible to effectively utilize the dust generated in the dryer drum to rationally prevent clogging of the filter cloth, and also to remove large and heavy dust while keeping the exhaust gas temperature constant. It is easy to adjust the degree of separation of light dry dust, and moreover, the large particle size and heavy dust collected by the bag filter can be taken out from the exhaust box together with the asphalt mixture recycled by the dryer drum and used. The purpose of the present invention is to provide a dust collector for asphalt recycling plants that can perform the following tasks.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a bag filter installed in an exhaust box provided at the end of the exhaust side of a dryer drum to collect dust in the exhaust gas sent from the exhaust box to an intake damper. The bagg filter is connected to the exhaust box by a pipe, and the pipe is provided with a blower that returns the dust collected by the bagg filter to the exhaust box through the pipe with outside air. The exhaust box is equipped with a centrifugal separator that separates the dust sent through the pipe into large, heavy dust and light dry dust, and releases the light dry dust into the exhaust gas.

[Effect]

The exhaust gas from the dryer drum is sent to the bag filter from the exhaust box. The bag filter uses a filter cloth to collect dust in the exhaust gas sent from the exhaust box, and discharges the purified exhaust gas through the filter cloth into the atmosphere through the exhaust fan.

In this way, the dust collected by the bag filter is immediately passed through the pipe and removed by the blower.
The dust is returned to the exhaust box, and a separator inside the exhaust box separates the heavy wet dust with asphalt mist attached to it, and the dry dust, which is dry and light without any mist attached, and the heavy wet dust remains together with the composite material. In addition, the light dry dust joins the exhaust gas and adheres to the asphalt mist in the exhaust gas, weakening the adhesion of the mist to the filter cloth. For this reason,
Dust can be used effectively and adhesion of dust to the filter cloth can be prevented as much as possible. The degree of separation of heavy wet dust to which asphalt mist is attached and light dry dust to which no mist is attached by the centrifugal separator is adjusted by changing the wind speed of the blower 13.
If the wind speed of the blower 13 is slowed down, the amount of light dry dust taken out into the duct will decrease,
When the wind speed is increased, the above will be reversed, but if the amount of outside air taken in by the blower decreases with this adjustment, the opening of the intake damper will be increased, and if the amount of outside air taken in by the blower increases, the intake damper will be increased. Keep the exhaust gas temperature constant by reducing the damper opening.

〔Example〕

FIG. 1 and FIG. 2 show an embodiment of the present invention, and numeral 1 in the figures represents a dryer drum. This dryer drum 1 is well known and is designed to heat asphalt pavement waste materials by hot air blown from a burner (not shown) while rotating in the circumferential direction. An exhaust box 2 is disposed at the exhaust side end of the dryer drum 1, and a bag filter 4 is connected to the exhaust box 2 via a duct 3.

The bag filter 4 has a large number of filter cloths 6 stretched in a casing 5, and allows the exhaust gas to pass through the filter cloths 6, thereby trapping dust in the exhaust gas. An exhaust fan 8 is connected to the bag filter 4 via a suction pipe 7.

The duct 3 is provided with an intake damper 9 that can be opened and closed to draw in outside air and lower the temperature of the exhaust gas, and the filter cloth 6 is made of a heat-resistant material and can handle high-temperature exhaust gas. It is said to be composed of

Further, a screw conveyor 1 is provided at the bottom of the casing 5 of the bag filter 4 to send out the dust that has been captured by the filter cloth 6 and fallen downward.
An air pressure feeding device 14 having a blower 13 connected to a pipe 12 is provided between a rotary feeder 11 connected to the screw conveyor 10 and the exhaust box 2. The air pressure feeding device 14 sends the dust captured by the filter cloth 6 and sent out through the screw conveyor 10 and the rotary feeder 11 to the exhaust box 2 by the action of the blower 13.
The side end portion is connected to a separator 15 provided within the exhaust box 2.

As shown in FIG. 2, the separator 15 connects the pipe 12 to the side of the outer cylinder 16 which is tapered at the bottom in the tangential direction of the side, and attaches the inner cylinder 17 to the upper part of the outer cylinder 16. The structure is such that the dust sent from the pipe 12 is swirled vigorously within the outer cylinder 16, relatively heavy wet dust is discharged downward as it is, and light dry dust is discharged upward from the inner cylinder 17. .

18 is an opening/closing lid provided at the bottom of the exhaust box 2; 19 is a mixer for mixing the asphalt mixture and dust discharged from the exhaust box 2; and 20 is a mixer provided in the casing 5 of the bag filter 4. It is a full plate.

Next, the operation of the dust collector for an asphalt recycling plant according to the present invention configured as described above will be explained.

The dryer drum 1, the exhaust fan 8, and the air pressure feeding device 14 are operated, and asphalt mixture is introduced into the dryer drum 1, and is heated by hot air from a burner in a well-known manner. The exhaust gas that worked to heat the asphalt mixture in the dryer drum 1 is sent into the casing 5 of the bag filter 4 through the exhaust box 2 and the dust 3, hits the bag full plate 20 and falls downward, and then is filtered. Cloth 6
The dust flows into the area where it is captured. The exhaust gas purified in this way is transferred to the suction pipe 7 and the exhaust fan 8.
It is released into the atmosphere from the chimney 21 through the air.

On the other hand, the dust captured by the filter cloth 6 of the bag filter 4 as described above falls below the casing 5 and is sent to the pipe 12 by the screw conveyor 10 and rotary feeder 11, and is then blown by the air blown by the blower 13. It is vigorously jetted into the separator 15. In this way separator 1
The dust ejected into the cylinder 5 rotates in the outer cylinder 16 and is separated into heavy wet dust and light dry dust.The heavy wet dust falls to the bottom and is mixed with the asphalt mixture in the mixer 19, and the The dry dust flies upwards from the inner cylinder 17 and passes from the dryer drum 1 to the exhaust box 2.
It adheres to the asphalt mist in the exhaust gas flowing through the duct 3 and coats the mist to reduce its adhesion to the filter cloth 6.

In the above, if the temperature of the exhaust gas is too high, the burner temperature is lowered or the opening of the intake damper 9 is increased to increase the intake amount of outside air. In addition to this, the temperature of the exhaust gas can also be adjusted by adjusting the amount of outside air taken in by the blower 13.

By the way, in order to effectively adhere dry dust to the asphalt mist in the exhaust gas, the flow velocity of the exhaust gas must be lower than before (1 to 3 m/sec).
It is a good idea to take measures such as increasing the diameter of the exhaust box to ensure this. In addition, if the filler is put into the exhaust box via an air pressure feeding device and a separator, or directly put into the exhaust box and allowed to adhere to the asphalt mist, asphalt mist adhesion to the filter cloth can be further suppressed. It becomes like this.

〔Effect of the invention〕

As explained above, the dust collector for an asphalt recycling plant of the present invention collects dust in the exhaust gas sent from the exhaust box in the exhaust box provided at the exhaust side end of the dryer drum. A baggage filter is connected to the exhaust box by a duct with an intake damper, and the baggage filter is connected to the exhaust box by a pipe, and the baggage filter is connected to the exhaust box through the pipe to return the dust collected by the baggage filter to the exhaust box with outside air. A blower is installed, and a centrifugal separator is installed in the exhaust box that separates the dust sent through the pipe into heavy dust with a large particle size and light dry dust, and releases the light dry dust into the exhaust gas. Since the structure is equipped with a separator, the light dry dust generated in the dryer drum is effectively utilized and attached to the asphalt mist in the exhaust gas, thereby effectively preventing clogging of the filter cloth of the bug filter. be able to.

In addition, by changing the blower air volume (air speed), it is possible to moderate the degree of separation of light dry dust and more effectively prevent dust from adhering to the filter cloth. It is also possible to adjust the opening degree of the damper to keep the exhaust gas temperature constant and prevent damage to the filter cloth and condensation.

Furthermore, the wet dust collected by the bag filter is separated by a centrifugal separator in the exhaust box and taken out together with the recycled composite material in the dryer drum, eliminating waste and providing a dedicated transport system for wet dust. There is also the advantage that there is no need to provide a separate one, and the overall structure is simplified.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a dust collector for an asphalt recycling plant according to the present invention;
FIG. 2 is a cross-sectional view of the separator. 1... Dryer drum, 2... Exhaust box, 4...
Bag filter, 14... Air pressure feeding device, 15... Separator.

Claims (1)

[Claims] 1 A bag filter 4 that collects dust in the exhaust gas sent from the exhaust box 2 is connected to an exhaust box 2 provided at the end of the exhaust side of the dryer drum 1 through a duct 3 equipped with an intake damper 9. The bag filter 4 is connected to the exhaust box 2 by a pipe 12, and the pipe 12 is provided with a blower 13 for returning the dust collected by the bag filter 4 to the exhaust box 2 through the pipe 12 with outside air. In addition, a centrifugal separator is installed in the exhaust box 2 to separate the dust sent through the pipe 12 into heavy dust with a large particle size and light dry dust, and to release the light dry dust into the exhaust gas. 15. A dust collector for an asphalt recycling plant, characterized in that a dust collector is provided with a dust collector.