JPH08218311A - Odor countermeasure recycling plant, and operation method therefor - Google Patents

Abstract

PURPOSE: To make quick starting possible for recycling with preheating time shortened for a deodorization furnace or the like. CONSTITUTION: With a burner 24 for a deodorization furnace set afire, combustion gas is sent, with its calorific power heightened gradually, to a dryer 1 through a deodorization furnace 23, a supply duct 26, and a combustion furnace 3. A burner 2 for the dryer is set afire when the hot air temperature at the entrance of the dryer rises to a specified level. On completion of preheating that is made by setting the burners 24 and 2 afire, throwing-in of substances to be recycled into the dryer 1 is started by operation of a throw-in conveyer 5, and fire in the burner 2 for the dryer is turned off. Preheating is executed with a wind regulating valve 40 opened half. Exhaust gas is returned to the deodorization furnace 23 through a return duct 22, and combustible component in the exhaust gas is burned there. Combustion gas from the deodorization furnace 23 is partly discharged out of a funnel 25, passing through an exhaust duct 27 and heat exchangers 34 and 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an odor control type recycling plant which heats and regenerates a material to be regenerated such as a waste pavement material containing asphalt and aggregate, and a method of operating the same.

[0002]

2. Description of the Related Art As an odor control type recycling plant,
Conventionally, a material to be regenerated including asphalt and aggregates is heated by a dryer, and the exhaust gas that has worked to heat the material to be regenerated in the dryer is put into a deodorizing furnace through a return duct having a heat exchanger to remove the odor in the exhaust gas. The combustible components that are elements are burned by the flame of the deodorizing furnace burner, and part of the combustion gas is sent to the dryer through the supply duct, and the remaining combustion gas is sent to the chimney through the exhaust duct through the heat exchanger and released to the atmosphere. It is known that they are discharged (Japanese Patent Publication No. 4-5232).
No. 3 publication. )

[0003]

In the above odor control type recycling plant, at the start of operation when the deodorizing furnace burner is ignited and the combustion gas is started to be sent to the dryer, heat is taken to the deodorizing furnace and the supply duct. At the same time, there is a time lag in the preheating of the deodorizing furnace, the supply duct, the dryer, etc., and the preheating of the dryer at the most downstream is the most delayed, so it takes a considerable time to start regeneration. This preheating (waiting) time varies depending on the downtime of the recycling plant (the temperature at the start of operation of the deodorizing furnace, the supply duct, etc.) and the atmospheric temperature, and it takes about 20 minutes in summer and 40 minutes in winter. .

The preheating time can be shortened by increasing the heat capacity of the deodorizing furnace burner and preheating the deodorizing furnace, the supply duct, etc. with the high temperature combustion gas. However, since the temperature gradient at the time of preheating becomes large, the deodorizing furnace, the supply duct, etc. are easily damaged and the service life becomes new.

One object of the present invention is to provide an odor control type recycling plant and a method for operating the odor control recycling plant which can quickly start the production operation of the heated regenerated material regardless of the preheating time of the deodorizing furnace, the supply duct and the like. Is.

Another object of the present invention is to provide an odor control type recycling plant capable of efficiently preheating a deodorizing furnace, a supply duct and the like, and an operating method thereof.

[0007]

In order to achieve the above object, an odor control type recycling plant according to the present invention is
A dryer that heats a material to be regenerated including asphalt and aggregate, and an exhaust gas that has worked to heat the material to be regenerated in the dryer is received through a return duct having a heat exchanger, and a combustible component that is an odor element in the exhaust gas. A deodorizing furnace that burns with a flame of a deodorizing furnace burner, a supply duct that sends a part of the combustion gas of this deodorizing furnace to the dryer, and the combustion gas remaining in the deodorizing furnace by the heat exchanger as exhaust gas in the return duct In an odor control type recycling plant equipped with an exhaust duct that heats the air and sends it to the chimney and discharges it to the atmosphere, a dryer burner is connected to the dryer via a combustion furnace, and the supply duct is connected to the combustion furnace. The supply duct is provided with a wind control valve for adjusting the opening of the supply duct in the vicinity of the combustion furnace.

A heating member heated by the flame of the deodorizing furnace burner may be provided inside the deodorizing furnace so as to intersect with the flow direction of the flame, and a return duct may be opened to the deodorizing furnace burner side of the heating member. preferable. Further, the heating member may be made of a refractory material, and a large number of flame circulation holes may be formed in this.

Further, the operating method of the odor control type recycling plant according to the present invention includes a dryer for heating a material to be regenerated containing asphalt and aggregate, a dryer burner connected to the dryer through a combustion furnace, A deodorizing furnace that receives exhaust gas that has heated the material to be regenerated in a dryer through a return duct that has a heat exchanger, and burns combustible components that are odorous elements in the exhaust gas with the flame of a deodorizing furnace burner, and this deodorizing furnace A supply duct for sending a part of the combustion gas to the dryer, and an exhaust duct for discharging the combustion gas remaining in the deodorizing furnace into the chimney after heating the exhaust gas in the return duct by the heat exchanger and discharging it to the atmosphere. A deodorizing furnace burner is ignited in an odor control type recycling plant equipped with a wind control valve provided in the supply duct for adjusting an opening of the supply duct. While gradually increasing the calorific value of the burner, the combustion gas of the deodorizing furnace burner is sent to the dryer through the deodorizing furnace, the supply duct, and the combustion furnace to preheat the deodorizing furnace, the supply duct, the combustion furnace, etc. Dryer inlet When the hot air temperature reaches the first predetermined temperature, the dryer burner is ignited, and when the exhaust gas temperature of the dryer reaches the predetermined temperature, the supply of the regenerated material to the dryer is started, and then the dryer gas inlet for the combustion gas. When the hot air temperature reaches the second predetermined temperature, the calorific value of the dryer burner is gradually lowered as the hot air temperature at the dryer inlet of the combustion gas rises to extinguish the dryer burner and control the combustion amount of the deodorizing furnace burner. The material to be regenerated is heated and regenerated.

The air-conditioning valve provided in the supply duct is opened halfway to start preheating of the supply duct and the like, and when the temperature of the hot air at the outlet of the deodorizing furnace becomes almost the temperature required for the regeneration of the regenerated material, the air-conditioning valve is opened. It is desirable that the structure be fully opened. In this case, it is preferable that the calorific value of the dryer burner be reduced almost at the same time as the air valve is fully opened.

[0011]

When the operation is started, the deodorizing furnace burner mainly preheats the deodorizing furnace and the supply duct, and the dryer burner mainly preheats the dryer. Therefore, the deodorizing furnace, the supply duct, the dryer and the like can complete preheating almost simultaneously and quickly. If the air-conditioning valve is opened halfway during preheating, the amount of combustion gas from the deodorizing furnace burner staying in the deodorizing furnace and supply duct and passing through to the dryer side is reduced, so the deodorizing furnace and supply duct are preheated efficiently. Like

Further, the heating member made of a refractory material provided in the deodorizing furnace causes the combustible component in the exhaust gas to come into contact with the combustible component. When a large number of flame circulation holes are formed in the heating member, the exhaust gas is efficiently mixed with the high-temperature combustion gas due to an appropriate flow resistance of the combustion gas, and is effectively deodorized.

After the deodorizing furnace burner is ignited, when the dryer inlet hot air temperature of the combustion gas reaches the first predetermined temperature, the deodorizing furnace, the supply duct and the dryer can be preheated almost at the same time. it can. If the air-conditioning valve is fully opened and the calorific value of the dryer burner is reduced at approximately the same time, fluctuations in the hot air temperature at the dryer inlet of combustion gas can be suppressed to a small level.

[0014]

1 to 5 show an embodiment of an odor control type recycling plant according to the present invention, in which reference numeral 1 is a dryer. A dryer burner 2 is provided at an end portion on the left side (right side in FIG. 2) of the dryer 1 via a combustion furnace 3, and a discharge tube 4 is provided at an end portion on the right side of FIG. A charging conveyor 5 is provided below the dryer burner 2 and the combustion furnace 3. The feeding conveyor 5 is composed of a recycled material feeder 6 withdrawing conveyor 7 and inclined conveyors 8 and 9.
Recycled materials such as asphalt waste materials sent via
Alternatively, the new aggregate sent from the new aggregate feeder 10 via the pull-out conveyor 11 and the inclined conveyors 8 and 9 is put into the dryer 1.

A pipe 14 of the additive supply device 13 and a pipe 16 of the asphalt supply device 15 are connected to the lower portion of the discharge pipe 4, and an after mixer 17 is provided at the bottom of the discharge pipe 4. The aftermixer 17 mixes the material to be regenerated heated by the dryer 1 or the new aggregate with an additive such as a filler and asphalt to form an asphalt mixture. Below the aftermisaki 17, there is provided a skip conveyor 19 for putting the asphalt mixture into the mixture silo 18. The dryer 1 rotates in the circumferential direction and heats the regenerated material, new aggregate, or the regenerated material and the new aggregate, which is put in the dryer 1 and is drawn horizontally in FIG.
Actually, the end portion on the side of the input conveyor 5 is high and the end portion on the side of the discharge cylinder 4 is low, and the end portion is provided in an inclined state.

A special filter (not shown) is provided inside the discharge cylinder 4 to give the discharge cylinder 4 a dust collecting function. A cyclone-type dust collector 21 is provided above the discharge pipe 4.
, And the dust collector 21 is connected to the deodorizing furnace 23 by a return duct 22.

A deodorizing furnace burner 24 is provided at one end of the deodorizing furnace 23. The deodorizing furnace 23 receives the entire amount of the exhaust gas that has heated the material to be regenerated in the dryer 1, burns the combustible components contained in the exhaust gas with the flame of the deodorizing furnace burner 24, and partially burns the combustion gas. 1 and to discharge the remaining combustion gas to the atmosphere,
At the other end, the combustion furnace 3 and the chimney 25 are individually connected by a supply duct 26 and an exhaust duct 27.

In the deodorizing furnace 23, a heating member 29 made of ceramics or other refractory material and having a large number of flame circulation holes 29a is arranged orthogonal to the flame flow direction by aligning the flame flow holes 29a with the flame flow direction. It is fixedly installed. The heating member 29 may be a plate-shaped member made of a refractory material and having an appropriate thickness, which is formed by penetrating the flame circulation hole 29a in the thickness direction thereof, and may have an appropriate outer diameter and wall thickness. Matching the axial direction of many ceramic tubes with a length with the flame flow direction (longitudinal direction of the deodorizing furnace),
They may be arranged in close contact with each other in a direction crossing the deodorizing furnace (direction perpendicular to the longitudinal direction). Heating member 29
Is brought into a red heat state by the combustion of the deodorizing furnace burner 24, and imparts an appropriate flow resistance to the burning gas, so that the deodorizing furnace 23 is heated by the high temperature combustion gas and the return duct 22.
The gas is efficiently mixed with the exhaust gas sent to, and the combustible components in the exhaust gas are efficiently burned to enhance the deodorizing effect. The return duct 22 opens inside the deodorizing furnace 23 between the deodorizing furnace burner 24 and the heating member 29.

A blower 31 is connected to the deodorizing furnace burner 24 through an air supply pipe 32 having a first heat exchanger 33. That is, the air supply pipe 32 connects one inlet 33a of the first heat exchanger 33 to the blower 31 and connects one outlet 33b to the deodorizing furnace burner 24. Return duct 22
Has a second heat exchanger 34, one inlet 34a of which is connected to the dust collector 21 and one outlet 34b of which is connected to the deodorizing furnace 23. A circulation fan 35 is provided between the dust collector 21 of the return duct 22 and the second heat exchanger 34.
And an opening / closing damper 36 is provided on the dust collector 21 side. The circulation fan 35 sends all of the exhaust gas that has worked to heat the material to be regenerated in the dryer 1 to the deodorizing furnace 23, and is usually based on the negative pressure (about 0 to -5 mmHg) on the dust collector 21 side. Controlled.

The exhaust duct 27 connects the other end of the deodorizing furnace 23 and the other inlet 33c of the second heat exchanger 34,
The other outlet 34d of the heat exchanger 34 is connected to the other inlet 33c of the first heat exchanger 33, and the first heat exchanger 3
The other outlet 33d of 3 is connected to the chimney 25. A wind control valve 40 is provided in the supply duct 26. Wind valve 4
0 is provided as close as possible to the combustion furnace 3 so that the preheating of the supply duct 26 by the deodorizing furnace burner 24 is well performed over its entire length (see FIGS. 2 and 4). The wind control valve 40 and the opening / closing damper 36 are of a variable type so that the opening can be freely set. Reference numeral 41 in FIG. 1 is a blower that sends air to the dryer burner 2.

Next, an operating method in the case of regenerating a material to be regenerated in the odor control type recycling plant configured as described above will be described with reference to FIG. First, the deodorizing furnace burner 23 is ignited, and the air conditioning valve 40 is gradually opened to a half open state. The combustion amount (heat generation amount) of the deodorizing furnace burner 23 is gradually increased to about 50% and combustion is continued as it is. The combustion gas of the deodorizing furnace 24 is supplied to the supply duct 26,
It is returned to the deodorizing furnace 33 through a gas flow path consisting of the combustion furnace 3, the dryer 1, the discharge tube 4, the dust collector 21, the second heat exchanger 34, and the return duct 22. Due to the above circulation of the combustion gas, the temperature of the gas flow paths 26, 3, 1, 4, 21, 22, etc. gradually rises, but the air flow regulating valve 40 is in a half-opened state, and the passage of the combustion gas is suppressed. Therefore, the deodorizing furnace 23 and the like can be efficiently preheated. The air conditioning valve 40 can be opened halfway in advance before ignition.

A part of the combustion gas of the deodorizing furnace burner 24 passes through the exhaust duct 27 and the first and second heat exchangers 33 and 34 by the action of the pressure due to the opening degree of the wind control valve 40 in the circulation passage. Then, it is released from the chimney 25 to the atmosphere. The combustion gas flowing through the exhaust duct 27 is returned to the return duct 22 by the second heat exchanger 34.
The exhaust gas is heated by the first heat exchanger 33, and the air sent to the deodorizing furnace burner 24 through the air supply pipe 32 is heated by the blower 31.

In this way, when the hot air temperature at the dryer inlet reaches the first predetermined temperature, for example, 300 ° C., the dryer burner 2 is ignited and the fuel discharge amount is gradually increased to the maximum (100%). After the ignition of the dryer burner 2,
The combustion amount of the deodorization furnace burner 24 is gradually increased, and when the dryer inlet hot air temperature reaches a third predetermined temperature, for example, 500 ° C., the combustion amount of the dryer burner 2 is set to about 800 ° C. at the outlet hot air temperature of the deodorization furnace 23. Gradually decrease it to about 50% as it rises.

In the above operation, when the exhaust gas temperature of the discharge cylinder 4 reaches a predetermined temperature of about 100 ° C., the feeding conveyor 5 is operated to start feeding the material to be regenerated into the dryer 1. After the material to be regenerated is charged, the combustible components in the exhaust gas are burned by the flame of the deodorizing furnace burner 24, so that there is no odor. The heating member 29 helps burn combustible components.

When the hot air temperature at the outlet of the deodorizing furnace reaches the temperature required for the regeneration of the material to be regenerated, that is, about 800 ° C., the air regulating valve 40 is gradually opened until it is fully opened. When the temperature rises to a predetermined temperature of about 700 ° C., the amount of fuel discharged from the dryer burner 2 is gradually reduced to finally extinguish the fire.

The deodorizing furnace burner 24 is thereafter controlled in its combustion amount so that the outlet hot air temperature of the deodorizing furnace 23 is maintained at its set value (700 to 800 ° C.). Also, the wind valve 4
The opening of 0 is controlled based on the temperature of the asphalt mixture, and the opening is increased when the temperature of the mixture is lower than a predetermined temperature, while the opening is increased when the temperature of the mixture is high. Make it smaller.

In the above, ignition of the dryer burner 2 and adjustment of the amount of heat generated by the dryer 1 and adjustment of the opening of the wind control valve 40 are performed according to the hot air temperature at the dryer inlet and the hot air temperature at the deodorizing furnace outlet. Instead of directly detecting the temperature and the hot air temperature at the outlet of the deodorizing furnace, it is possible to detect the temperature of a portion having a correlation with them and indirectly control the temperature.

Adjustment of the opening degree of the wind control valve 40, the dryer burner 2
Ignition and fire extinguishing of the
It is automatically controlled by a control device such as a computer. In this case, the actual control varies depending on the conditions such as the type of mixture, the operation suspension time, and the outside air temperature, so it is advisable to prepare some automatic operation patterns according to those conditions.

As in the odor control type recycling plant of Japanese Patent Publication No. 4-52323, another third heat exchanger is provided in the duct between the branch portion of the supply duct 26 and the deodorizing furnace 23, and then returned. The exhaust gas flowing through the duct 22 is the second
The deodorizing furnace 23 passes through the heat exchanger 34 and the third heat exchanger described above.
It may be configured to be returned to.

[0030]

As described above, the odor control type recycling plant according to the present invention uses the dryer for heating the material to be regenerated containing asphalt and the aggregate, and the exhaust gas that has heated the material to be regenerated in the dryer. A deodorizing furnace that receives via a return duct having a heat exchanger and burns the combustible components that are the odorous elements in the exhaust gas with the flame of the deodorizing furnace burner, and a part of the combustion gas of this deodorizing furnace that is sent to the dryer. In the odor control type recycling plant equipped with a duct and an exhaust duct for discharging the combustion gas remaining in the deodorizing furnace to the chimney after heating the exhaust gas in the return duct by the heat exchanger and discharging the air to the dryer. A dryer burner is connected through the combustion furnace, the supply duct is connected to the combustion furnace, and the opening of the supply duct is set to the supply duct. An air conditioning valve for adjusting is provided in the vicinity of the combustion furnace, and the operation method of the odor control type recycling plant is a dryer for heating a material to be regenerated including asphalt and aggregate, and a combustion for the dryer. A burner burner connected through a furnace, and the exhaust gas that has worked to heat the material to be regenerated in the dryer is received through a return duct having a heat exchanger, and a combustible component that is an odor element in the exhaust gas is deodorized in the furnace burner. Deodorizing furnace that burns with the flame of, the supply duct that sends a part of the combustion gas of this deodorizing furnace to the dryer, and the combustion gas remaining in the deodorizing furnace after heating the exhaust gas in the return duct by the heat exchanger , An odor control type recycling plant provided with an exhaust duct for sending to a chimney and discharging to the atmosphere, and a wind control valve provided in the supply duct for adjusting the opening of the supply duct By igniting the deodorizing furnace burner and gradually increasing the heating value of the deodorizing furnace burner, the combustion gas of the deodorizing furnace burner is sent to the dryer through the deodorizing furnace, the supply duct, and the combustion furnace, and thereby the deodorizing furnace, the supply duct, and the combustion furnace. Etc., the dryer burner is ignited when the hot air temperature at the dryer inlet of the combustion gas reaches the first predetermined temperature, and the supply of the regenerated material to the dryer is started when the exhaust gas temperature of the dryer reaches the predetermined temperature. After that, when the dryer inlet hot air temperature of the combustion gas reaches the second predetermined temperature, the calorific value of the dryer burner is gradually decreased as the dryer inlet hot air temperature of the combustion gas rises to extinguish the dryer burner, Since it is configured to continue heating and regenerating the material to be regenerated by controlling the combustion amount of the deodorization furnace burner, the preheating of the deodorization furnace and the supply duct etc. is almost At the same time, the regeneration operation can be completed quickly and the regeneration operation can be started quickly. Further, since the temperature gradient at the time of preheating can be reduced, it is possible to reduce damage to the constituent members and prolong the service life.

By providing a heating member inside the deodorizing furnace, the deodorizing effect is improved. Further, when the heating member is made of a refractory material and a large number of flame circulation holes are formed in this, contact mixing of the combustion gas and the exhaust gas is efficiently performed, and the combustible components in the exhaust gas are completely combusted. The deodorizing effect can be made more complete.

When preheating is performed with the air conditioner valve in a half-opened state, the amount of the combustion gas of the deodorizing furnace burner staying in the deodorizing furnace or the like and passing through to the dryer side is reduced, so that preheating can be efficiently performed. Further, when the air-conditioning valve is fully opened and the calorific value of the dryer burner is reduced substantially at the same time, the fluctuation of the hot air temperature at the dryer inlet of the combustion gas can be reduced, and the regeneration can be favorably performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an odor control type recycling plant according to the present invention.

FIG. 2 is also a plan view.

FIG. 3 is likewise a front view.

FIG. 4 is likewise a side view.

FIG. 5 is a cross-sectional view of a deodorizing furnace burner and a deodorizing furnace.

FIG. 6 is a diagram for explaining an operating method of the odor control type recycling plant according to the present invention.

[Explanation of symbols]

 1 Dryer 2 Dryer Burner 3 Combustion Furnace 22 Return Duct 23 Deodorizing Furnace 24 Deodorizing Furnace Burner 26 Supply Duct 27 Exhaust Duct 29 Heating Member 29a Flame Distribution Hole 40 Wind Control Valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tomohiro Gomachi, 6-70, Mitsuhashi, Omiya-shi, Saitama, Japan, Tomado Co., Ltd., General Engineering Department (72) Imamasa Yamabe, 6-70, Mitsuhashi, Omiya, Saitama Prefecture, Japan General engineering department

Claims (6)

[Claims] 1. A dryer for heating a material to be regenerated containing asphalt and aggregate, and an exhaust gas which has worked to heat the material to be regenerated in the dryer through a return duct having a heat exchanger and the odor in the exhaust gas. A deodorizing furnace that burns combustible components that are elements with the flame of a deodorizing furnace burner, a supply duct that sends a part of combustion gas of this deodorizing furnace to the dryer, and combustion gas remaining in the deodorizing furnace by the heat exchanger. In an odor control type recycling plant equipped with an exhaust duct that heats exhaust gas in a return duct and then sends it to a chimney and discharges it to the atmosphere, a dryer burner is connected to the dryer via a combustion furnace, and the supply to the combustion furnace is performed. The duct is connected, and the supply duct is provided with a wind control valve for adjusting the opening degree of the supply duct in the vicinity of the combustion furnace. Countermeasure recycling plant. 2. A heating member heated by the flame of the deodorizing furnace burner is provided inside the deodorizing furnace so as to intersect with the flow direction of the flame, and a return duct is opened to the deodorizing furnace burner side of the heating member. The odor control type recycling plant according to claim 1. 3. The odor control type recycling plant according to claim 2, wherein the heating member is made of a refractory material and has a large number of flame circulation holes. 4. A drier for heating a material to be regenerated containing asphalt and aggregate, a dryer burner connected to the dryer via a combustion furnace, and heat exchange of exhaust gas used to heat the material to be regenerated in the dryer. A deodorizing furnace that receives a combustible component, which is an odor element in the exhaust gas by a flame of a deodorizing furnace burner, and a supply duct that sends a part of combustion gas of the deodorizing furnace to the dryer. ,
After the exhaust gas in the return duct is heated by the heat exchanger with the combustion gas remaining in the deodorization furnace, the exhaust duct is sent to the chimney and discharged to the atmosphere, and the opening of the supply duct provided in the supply duct is adjusted. In a odor control type recycling plant equipped with a wind control valve, the combustion gas of the deodorization furnace burner is ignited by gradually igniting the deodorization furnace burner and gradually increasing the heat generation value of the deodorization furnace burner through the deodorization furnace, the supply duct and the combustion furnace. To a dryer to preheat the deodorizing furnace, the supply duct, the combustion furnace, etc., and when the hot air temperature at the dryer inlet of the combustion gas reaches the first specified temperature, the dryer burner is ignited, and the exhaust gas temperature of the dryer reaches the specified temperature. Then, the supply of the regenerated material to the dryer is started, and then, when the temperature of the hot air at the dryer inlet of the combustion gas reaches the second predetermined temperature, The heating value of the burner burner is gradually lowered as the temperature of hot air at the dryer inlet of the combustion gas rises to extinguish the dryer burner, and the combustion amount of the deodorizing furnace burner is controlled to continue heating and regenerating the material to be regenerated. Characteristic odor control recycling plant operation method. 5. The air conditioning valve provided in the supply duct is opened halfway to start preheating of the supply duct and the like, and the air conditioning is performed when the hot air temperature at the outlet of the deodorizing furnace becomes almost the temperature required for regeneration of the material to be regenerated. The operating method of an odor control type recycling plant according to claim 4, wherein the valve is fully opened. 6. The method of operating an odor control type recycling plant according to claim 5, wherein the calorific value of the dryer burner is reduced at substantially the same time as the air-conditioning valve is fully opened.