JPH0527521Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to an exhaust system in an asphalt waste material regeneration plant, and particularly relates to an exhaust system connected to a dryer in a regeneration plant that regenerates asphalt pavement waste material.

"Prior Art" Conventionally, an asphalt waste recycling plant that recycles asphalt pavement waste has been known as one of the devices for producing an asphalt mixture for road paving.

This asphalt waste material recycling plant puts crushed asphalt pavement waste material (hereinafter abbreviated as waste material) into a dryer and heats it to a predetermined moisture content and temperature. Add a predetermined amount of filler (stone powder) to the waste material
By adding additives such as asphalt or asphalt, or an appropriate amount of new heated aggregate, it is used as recycled asphalt mixture.

"Problems to be solved by the invention" By the way, in the above-mentioned asphalt waste material recycling plant, when drying and heating the waste material,
For example, if the temperature of the waste material exceeds 600℃, odor gas and blue or yellowish brown gas (referred to as blue smoke) will be generated inside the dryer.
Problems arise when this gas is released into the outside air through an exhaust passage connected to the dryer.

For this reason, conventionally, the drying and heating temperature of waste materials in the dryer is generally limited to below the above temperature, but even with this temperature limit,
The generation of blue smoke is unavoidable due to the properties of waste materials.

Such a problem contaminates the outside air near the asphalt waste material recycling plant, and there is a strong demand for countermeasures against this problem.

"Means for Solving the Problems" The present invention aims to provide an exhaust system for an asphalt waste material recycling plant that can effectively solve the conventional problems mentioned above. The exhaust system is such that a dryer that heats asphalt waste is connected with an exhaust passage that guides the gas generated inside the dryer to the outside, and in the middle of this exhaust passage, the exhaust gas discharged from the dryer is recirculated. An afterburner for combustion is provided, and a temperature meter for measuring the exhaust gas temperature in the exhaust passage is provided downstream of the afterburner in the exhaust passage, and an output from the temperature meter is provided to the temperature meter. The present invention is characterized in that a control unit is connected to control the combustion temperature of the afterburner based on information on exhaust gas temperature.

"Operation" The asphalt waste material regeneration plant according to the present invention has the above-described configuration, so that the exhaust gas discharged from the dryer is re-burned by the afterburner, and the unburned substances contained in the exhaust gas are re-burned. Completely burns the exhaust gas, thereby removing the odor from the exhaust gas and preventing it from turning blue or yellowish brown. Since the combustion temperature of the afterburner is accurately controlled by the control unit, efficient re-combustion can be achieved without wasting fuel.

``Example'' An example of the present invention will be described below with reference to FIGS. 1 and 2.

Reference numeral 1 in FIG. 1 indicates an asphalt waste material regeneration plant (hereinafter referred to as a regeneration plant) to which this embodiment is applied, in which waste material is stored, a waste material feeder 2 for cutting out the waste material, and a waste material feeder 2 in which new aggregate is stored. a new aggregate feeder 3 that cuts out the aggregate, conveyors 5 and 6 that transports the waste material and new aggregate cut out from these feeders 2 and 3 toward the dryer 4, and the dryer 4.
A filler supply device 9, an asphalt supply device 10, which sprays filler, asphalt, and a softener onto the waste materials and new aggregates that are dried and heated in the dryer 4 via sprays 7 and 8 disposed therein;
and a softener supply device 11, conveyor scales 12 and 13 attached to each of the conveyors 5 and 6 to measure the conveyance amount of waste material and new aggregate, these conveyor scales 12 and 13, and each of the above-mentioned supply devices 9. , 10, 11 and controls each supply device 9, 10, 11 based on the output information from the conveyor scales 12, 13, and a control unit 14 which is electrically connected to the conveyor scales 12, 13 and controls each supply device 9, 10, 11, and the recycled asphalt mixture produced in the dryer 4. A bucket conveyor 16 that conveys the material to the silo 15, an exhaust gas recirculation device 17 that is connected to the dryer 4 and returns the gas inside the dryer 4 to the burner section 4a of the dryer 4, and a gas recirculation device 17 that guides the gas inside the dryer 4 to the outside. , exhaust device 18 according to this embodiment
It is composed of:

This exhaust device 18 includes an exhaust passage 19 connected to the dryer 4 and an afterburner 20 provided in the middle of the exhaust passage 19 to reburn the exhaust gas discharged from the dryer 4.

More specifically, the exhaust passage 19
As shown in the figure and FIG. 2, it is equipped with an exhaust fan 21 for sending out exhaust gas to the outer end, and a chimney 22 provided downstream of the exhaust fan 21, and the tip of the chimney 22. On the inner surface of the vicinity,
A refractory material 23 is attached to a predetermined length from the tip, and the afterburner 20 is attached to the portion where the refractory material 23 is attached.

In this embodiment, as shown in FIG. 2, this afterburner 20 is arranged so as to be located approximately at the center of the chimney 22, and is connected to a gas cylinder (LPG cylinder) 24 arranged outside the chimney 22. It is connected to the air inlet 25.

On the other hand, the afterburner 2 of the chimney 22
A temperature measuring device 26 for measuring the exhaust gas temperature in the chimney 22 is provided downstream of the temperature measuring device 26, and a control unit 27 is connected to the temperature measuring device 26.

This control unit 27 controls the gas cylinder 24
It is electrically connected to the flow control valves 28 and 29 provided corresponding to the air inlet 25 and the automatic ignition device 20a of the afterburner 20, and is connected to the exhaust gas temperature information output from the temperature measuring device 26. Based on this, the opening degree of each flow control valve 28, 29 is adjusted to control the combustion temperature of the burner 20 ignited by the automatic ignition device 20a.

However, the regeneration plant 1 equipped with the exhaust system 18 of this embodiment configured in this manner starts up each component to produce recycled asphalt mixture, adjusts the temperature of exhaust gas, and operates the chimney 22. Maintains good quality of exhaust gas emitted from.

That is, the recycled asphalt mixed material is produced by cutting out waste material and, if necessary, new aggregate from the waste material feeder 2 and the new aggregate feeder 3, as in the past.
These are put into the dryer 4 by conveyors 5 and 6, and dried and heated to a predetermined moisture content and temperature. , a predetermined amount of filler, asphalt, and a softener are added from the asphalt supply device 10 and the softener supply device 11 via the sprays 7 and 8 to produce a recycled asphalt mixture. The material is transported from the dryer 4 to the silo 15 by a bucket conveyor 16 and stored.

Part of the gas generated in the dryer 4 during the production of the recycled asphalt mixture mentioned above is returned to the dryer 4 by the exhaust circulation device 17, and the remaining part is returned to the dryer 4 through the exhaust passage 19. If the exhaust gas released to the outside air through this exhaust passage 19 is accompanied by an odor, or
If bluing or yellowing is observed, the operator operates the automatic ignition device 20a via the control unit 27 to ignite the afterburner 20, and the flame of the afterburner 20 causes
When the exhaust gas reaches the tip of the chimney 22, it is re-combusted.

The strength of the flame of the afterburner 20 during this reburning is adjusted to a state necessary to completely burn and decompose the unburned gas in the exhaust gas. This is done by adjusting the amount of gas to be supplied and the amount of air to be supplied by the control unit 27 based on information from the temperature measuring device 26 installed on the downstream side.

The reburning temperature of the exhaust gas, which is a control factor for such an adjustment operation, is determined by, for example, the temperature of the exhaust gas when it is discharged from the dryer 4, the amount of waste material, or the amount of new aggregate, filler, etc. that is mixed with the waste material. It is set according to the amount of asphalt, etc.

Therefore, efficient re-combustion is performed by the afterburner 20 without wasting fuel, and this re-combustion completely decomposes the unburned gas in the exhaust gas, and as a result, the odor of the exhaust gas is reduced. It is erased and decolorized to prevent contamination of the outside air.

On the other hand, ignition of the afterburner 20 is achieved by not only the above-mentioned manual operation, but also by installing a detector that detects the components that cause the odor and coloring using a component analyzer such as gas chromatography. The automatic ignition device 20a may be operated automatically via the control unit 27 based on a signal from the ignition unit 27.

It should be noted that the various shapes and dimensions of each component device shown in the above embodiments are merely examples, and can be variously changed based on design requirements and the like.

For example, the position where the afterburner 20 is installed is not limited to the vicinity of the tip of the chimney 22, but can be installed at any appropriate position in the exhaust passage 19. Also, the gas used for re-combustion
Not only LPG but also city gas etc. may be used.

Furthermore, during re-combustion, not only the afterburner 20 but also as shown in FIGS. 3 and 4,
A chimney 22 is located at a position facing the afterburner 20.
A metal net 30 may be disposed so as to cross the area, and the metal net 30 may be brought into a red-hot state by the afterburner 20 and brought into contact with the exhaust gas. As shown in the figure, a plurality of afterburners 20 may be provided to expand the combustion range.

"Effects of the invention" As explained above, the exhaust system for the asphalt waste recycling plant according to the invention has an exhaust passage connected to the dryer that heats the asphalt pavement waste to guide the gas generated inside the dryer to the outside. An afterburner for re-burning the exhaust gas discharged from the dryer is provided in the middle of the exhaust passage, and further, the temperature of the exhaust gas in the exhaust passage is measured downstream of the afterburner in the exhaust passage. The present invention is characterized in that a temperature measuring device is provided, and a control unit is connected to the temperature measuring device to control the combustion temperature of the afterburner based on information on the exhaust gas temperature outputted from the temperature measuring device, thereby eliminating unnecessary waste. Efficient re-combustion is performed by the afterburner without consuming fuel, and this re-combustion completely decomposes the unburned gas in the exhaust gas, eliminating the odor of the exhaust gas and turning it blue or yellowish-brown. It has excellent effects such as being able to eliminate pollution and prevent pollution of the outside air.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show an embodiment of the present invention, Fig. 1 is a schematic diagram showing an asphalt regeneration plant to which the embodiment is applied, and Fig. 2 omits a part of the embodiment. The enlarged views, FIGS. 3 and 4, and FIGS. 5 and 6 respectively show other embodiments of the present invention, and FIGS. 3 and 5 show the main parts of each embodiment. A vertical cross-sectional view, FIG. 4 is a view taken along the - line in FIG. 3, and FIG. 6 is a view taken along the - line in FIG. 5. 1... (asphalt) regeneration plant, 18...
...Exhaust device, 19...Exhaust passage, 20...Afterburner, 21...Exhaust fan, 22...Chimney,
23... Fireproof material, 24... Gas cylinder, 25...
Air inlet, 26...Temperature meter, 27...Control unit, 30...Metal mesh.

Claims (1)

[Scope of utility model registration request] A dryer that heats asphalt pavement waste is connected with an exhaust passage that guides gas generated inside the dryer to the outside, and an afterburner is installed in the middle of this exhaust passage to reburn the exhaust gas discharged from the dryer. Further, a temperature measuring device for measuring the exhaust gas temperature in the exhaust passage is provided downstream of the afterburner in the exhaust passage, and information on the exhaust gas temperature output from the temperature measuring device is provided to the temperature measuring device. An exhaust system for an asphalt waste material regeneration plant, characterized in that the exhaust system is connected to a control unit that controls the combustion temperature of the afterburner based on the following.