US20130192500A1

US20130192500A1 - Fire grate type incineration apparatus

Info

Publication number: US20130192500A1
Application number: US13/756,832
Authority: US
Inventors: Jong Soo Jurng; Sung Min Chin; Eun Seuk PARK; Min Su Kim
Original assignee: Korea Advanced Institute of Science and Technology KAIST
Current assignee: Korea Advanced Institute of Science and Technology KAIST
Priority date: 2012-02-01
Filing date: 2013-02-01
Publication date: 2013-08-01
Also published as: KR101144236B1

Abstract

The present disclosure relates to a fire grate type incineration apparatus, which includes movable fire grates and fixed fire grates alternatively arranged in a step pattern and incinerates waste while moving the waste to a discharge hole by the operation of the movable fire grates, wherein a channel is formed in the fixed fire grates so that a coolant cools the fixed fire grates while flowing along the channel, wherein the air introduced into the movable fire grates cools the movable fire grates and then is preheated and supplied into the incineration apparatus through an exhaust hole formed in the movable fire grates.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2012-0010293, filed on Feb. 1, 2012, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference.

BACKGROUND

1. Field
The present disclosure relates to a fire grate type incineration apparatus, and more particularly, to protecting a fire grate from high-temperature heat generated when incinerating waste such as refuse-derived fuel (RDF) and refuse plastic fuel (RPF) with a high caloric value.
In addition, the fire grate type incineration apparatus of the present disclosure is configured to prevent a melt generated at combustion of waste from falling into gaps in fire grates in order to suppress the generation of non-combusted waste.
2. Description of the Related Art
An incineration apparatus for incinerating waste is classified into a fire grate type incineration apparatus, a fluidized-bed type incineration apparatus, a revolving-furnace type incineration apparatus or the like. Among them, the fire grate type incineration apparatus includes plural stages of fire grates disposed in an incinerator, and waste is incinerated while moving on the fire grates.
In order to extend the life of a fire grate which is heated to a high temperature at incineration of waste and decrease the generation of contaminant caused by incomplete combustion or the like, the fire grate should be suitably cooled. In general cases, either air cooling or water cooling method is selectively used.
In the air cooling, the air for combustion is supplied to the lower portion of the fire grate to cool the fire grate. In the water cooling method, a coolant tube is installed to prevent high-temperature corrosion which is a biggest drawback of the air cooling method, and the fire grate is cooled by a coolant flowing in the coolant tube.
Japanese Unexamined Patent Publication No. 2000-240926 discloses a water cooling fire grate having a U-shaped conduct provided at the front surface, and Korean Unexamined Patent Publication No. 2002-091022 discloses a fixed water-cooling fire grate where a coolant cools the fire grate while circulating a diaphragm in the fire grate. In addition, Korean Patent Registration No. 10-0635407 discloses a fire grate which variably adjusts temperature of the fire grate by using a heat transfer adjustment member which increases/decreases heat transfer by changing a thermal resistance by thermally deforming a coolant tube according to temperature.
However, the water-cooling fire grate cools a fixed end and a movable end of the fire grate without distinction, which increases costs and results in a complicated structure of a coolant conduit or the like.

RELATED LITERATURES

Patent Literatures

(Patent Literature 1) Japanese Unexamined Patent Publication No. 2000-240926
(Patent Literature 2) Korean Unexamined Patent Publication No. 2002-091022
(Patent Literature 3) Korean Patent Registration No.10-0635407

SUMMARY

The present disclosure is directed to providing a fire grate type incineration apparatus configured to enhance cooling efficiency of a fire grate and prevent corrosion of the fire grate.
The present disclosure is also directed to providing a fire grate type incineration apparatus configured to improve combustibility by preventing a melt generated at combustion of waste from falling into gaps of the fire grate.
In one aspect, there is provided a fire grate type incineration apparatus, which includes movable fire grates and fixed fire grates alternately arranged in a step pattern and incinerates waste input thereto while moving the waste toward a discharge hole by the operation of the movable fire grates, wherein a channel is formed in the fixed fire grates so that a coolant cools the fixed fire grates while flowing along the channel, and air introduced into the movable fire grates is supplied into the incineration apparatus after cooling the fire grates through an exhaust hole formed in the movable fire grates.
According to an embodiment of the present disclosure, a channel tube may be formed in the front end of the fixed fire grate toward the inside of the fire grate type incineration apparatus to which waste is continuously input, and the channel tube may be surrounded by a shield plate.
According to an embodiment of the present disclosure, an inlet tube and an outlet tube may be formed at the rear end of the fixed fire grate, and the inlet tube and the outlet tube may be connected to the channel tube.
According to an embodiment of the present disclosure, a shield plate may be formed at the upper surface of the fixed fire grate.
According to an embodiment of the present disclosure, an exhaust hole may be formed at the front end of the movable fire grate toward the inside of the fire grate type incineration apparatus to which waste is continuously input, and air introduced into the movable fire grate may be preheated and supplied into the fire grate type incineration apparatus through the exhaust hole.
According to an embodiment of the present disclosure, the shield plate may be made of chrome steel or ceramic material.
According to an embodiment of the present disclosure, the movable fire grates or the fixed fire grates located to connect each other in the lateral direction of the same level may have steps at sides thereof so as to be engaged with another movable fire grate or fixed fire grate at the sides thereof.
As described above, the fire grate type incineration apparatus according to the present disclosure may reduce the cost of equipment by cooling a fixed fire grate in a water-cooling manner and cooling a movable fire grate in an air-cooling manner to reduce a coolant conduit. In addition, in case of the movable fire grate, by supplying a combustion air to an edge portion of the fire grate, an interference of waste and the combustion air may be minimized, thereby facilitating the combustion reaction.
In addition, the fire grate type incineration apparatus according to the present disclosure may prevent corrosion by maximizing a heat transfer area and thus minimizing a heat load so that the coolant may cool the entire fixed fire grate. In particular, low-temperature corrosion of the fire grate caused by excessive cooling may be prevented by allowing the coolant to intensively flow at the front end of the fixed fire grate where the combustion heat is concentrated.
Further, the fire grate type incineration apparatus according to the present disclosure may extend the life cycle of the fire grate and reduce replacement costs by changing the material of the top portion of the fire grate to which a great combustion heat load is applied, and may also extend the life cycle of the fire grate by installing a shield plate to fundamentally prevent a contact between the cooling portion and the corrosive gas.
Furthermore, the fire grate type incineration apparatus according to the present disclosure may suppress the generation of non-combusted waste by preventing melt waste from falling through gaps in the fire grate disposed in the lateral direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the disclosed exemplary embodiments will be more apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a diagram showing a fire grate type incineration apparatus according to an embodiment of the present disclosure;

FIG. 2 is a perspective view showing a fixed fire grate of FIG. 1;

FIG. 3 is a diagram showing a channel in the fixed fire grate of FIG. 2;

FIG. 4 is a cross-sectional view showing the channel in the fixed fire grate of FIG. 2;

FIG. 5 is a cross-sectional view showing a shield plate of the fixed fire grate of FIG. 2;

FIG. 6 is a cross-sectional view showing a shield plate for protecting a coolant channel of the fixed fire grate of FIG. 5;

FIG. 7 is a diagram showing an exhaust hole of a movable fire grate of FIG. 1; and

FIG. 8 is a diagram showing an arrangement of fire grates located in the lateral direction.

DETAILED DESCRIPTION OF MAIN ELEMENTS

100: fire grate type incineration apparatus
101: input hole
103: exhaust hole
105: discharge hole
110: fixed fire grate
111: inlet tube
112: outlet tube
113: channel
114: channel tube
115: shield plate
120: movable fire grate
121: exhaust hole
130: step
140: expansion device

DETAILED DESCRIPTION

Hereinafter, a fire grate type incineration apparatus according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.
In the drawings, FIG. 1 is a diagram showing a fire grate type incineration apparatus according to an embodiment of the present disclosure, FIG. 2 is a perspective view showing a fixed fire grate of FIG. 1, FIG. 3 is a diagram showing a channel in the fixed fire grate of FIG. 2, FIG. 4 is a cross-sectional view showing the channel in the fixed fire grate of FIG. 2, FIG. 5 is a cross-sectional view showing a shield plate of the fixed fire grate of FIG. 2, FIG. 6 is a cross-sectional view showing a shield plate for protecting a coolant channel of the fixed fire grate of FIG. 5, FIG. 7 is a diagram showing an exhaust hole of a movable fire grate of FIG. 1, and FIG. 8 is a diagram showing an arrangement of fire grates located in the lateral direction.
As shown in FIG. 1, the fire grate type incineration apparatus 100 includes an input hole 101 formed at one side of the upper portion thereof to input waste, an exhaust hole 103 formed at the other side of the upper portion to exhaust a combustion gas, and a discharge hole 105 formed at the other side of the lower portion to discharge incinerated material.
In addition, fire grates 110, 120 arranged in a step pattern are formed from the input hole 101 toward the discharge hole 105. The fire grates 110, 120 are classified into a fixed fire grate 110 and a movable fire grate 120, and the fixed fire grates 110 and the movable fire grates 120 are alternately arranged in a step pattern. In the fixed fire grate 110 and the movable fire grate 120 configured as above, the movable fire grate 120 is movable in the forward and rearward direction toward the inside of the incineration apparatus 100 by an expansion device 140 connected at the rear portion thereof as much as an extension length of the expansion device 140.
Therefore, the waste input through the input hole 101 is incinerated while falling downwards by being pushed due to the movement of the movable fire grate 120, and gradually moves toward the discharge hole 105. In detail, the waste falling on the upper surface of the fixed fire grate 110 located below the movable fire grate 120 moves to the front end of the fixed fire grate 110 due to the movement of the movable fire grate 120 and then falls onto the upper surface of a movable fire grate 120 located at a lower position from the front end of the fixed fire grate 110. In this state, if the movable fire grate 120 moves rearwards, the waste located on the upper surface of the movable fire grate 120 falls onto the upper surface of a fixed fire grate 110 located at a lower position, and as the movable fire grate 120 moves forwards, the waste is moved to the front end of the fixed fire grate 110 and falls downwards. In this way, waste moves and is incinerated.
The fixed fire grate 110 and the movable fire grate 120 configured as above may be corroded due to corrosive gas such as HCl and SOx among the combustion gas, and this corrosion is classified into high-temperature corrosion occurring at about 350° C. or above and low-temperature corrosion occurring at about 150° C. or below. In other words, since the corrosion speed at the metal surface is slowest in the range of 150° C. to 330° C., in order to protect the fire grates 110, 120, the fire grates 110, 120 should be cooled to protect both high-temperature corrosion and low-temperature corrosion. In particular, in comparison to the fixed fire grate 110, the movable fire grate 120 is less exposed to the combustion heat. Therefore, the fixed fire grate 110 may be cooled by using a water-cooling manner with excellent cooling efficiency, and the movable fire grate 120 may be cooled by using an air-cooling manner.
Hereinafter, a water-cooling fixed fire grate will be described in detail.
Among the fixed fire grates 110 shown in FIG. 1, FIG. 2 shows some fixed fire grates 110 located in the same level.
As shown in FIGS. 2 and 3, the fixed fire grate 110 is connected to an inlet tube 111 and an outlet tube 112 at the rear end thereof, and after a coolant is introduced into the fixed fire grate 110 through the inlet tube 111, the coolant flows along a channel 113 formed in the fixed fire grate 110 and absorbs heat of the fixed fire grate 110. In addition, the coolant is discharged through the outlet tube 112 connected to the rear end of the fixed fire grate 110.
Since the coolant introduced into the fixed fire grate 110 flows along the channel 113 in the fixed fire grate 110, absorbs heat of the fixed fire grate 110 and is then discharged, the temperature of the fixed fire grate 110 is maintained in the range of 150° C. to 330° C.
The pattern of the channel 113 may be changed in consideration of the flow rate of the coolant and the heat exchange efficiency of the fixed fire grate 110, and the pattern of the channel 113 shown in FIG. 3 is just an example of various patterns.
In the fixed fire grate 110 configured as above, a portion relatively greatly exposed to the waste combustion heat is a front end portion of the fixed fire grate 110. Therefore, the channel 113 of the fixed fire grate 110 may be configured to allow the coolant to pass through the front end of the fixed fire grate 110 as shown in FIG. 4 and also to allow a great flow rate of the coolant.
In addition, as described above, the waste combusted by the movable fire grate 120 located at an upper position falls onto the upper surface of the fixed fire grate 110. Therefore, the front end of the fixed fire grate 110 and the upper surface of the fixed fire grate 110 are greatly exposed to the combustion heat. In order to prevent corrosion caused by the combustion heat, as shown in FIG. 5, the shield plate 115 is fixed to the upper surface of the fixed fire grate 110. The shield plate 115 is made of chrome steel, ceramic material or the like, which may endure a high-temperature head load.
In addition, as shown in FIG. 6, at the channel 113 formed in the front end of the fixed fire grate 110, the shield plate 115 is provided to surround the channel 113 in order to prevent a corrosive gas from contacting a channel tube 114 so as to prevent corrosion.
As shown in FIG. 7, an exhaust hole 121 is formed at the front end of the movable fire grate 120 in order to supply a combustion gas. Since an external air cools the movable fire grate 120 and then is supplied into the incineration apparatus 100 through the exhaust hole 121 formed at the front end, the temperature of the movable fire grate 120 may be maintained in the range of 150° C. to 330° C., and also the external air preheated while passing through the movable fire grate 120 may improve the combustion efficiency of the incineration apparatus 100.
Regarding the movable fire grates 120 and the fixed fire grates 110 according to the present disclosure, fire grates 110, 120 adjacent to each other in the same level in the right and left direction as shown in FIGS. 2 and 8 have a combination structure which allows engagement between them. In detail, steps 130 are formed at the sides of the fire grates 110, 120, and the steps 130 of adjacent fire grates 110, 120 are engaged with each other to close a gap between the fire grates 110, 120 having the steps 130, which may prevent waste or an incinerated melt from falling. In addition, the steps 130 formed at the sides of the fire grates 110, 120 reinforce the fire grates 110, 120 and prevent thermal deformation thereof, which may prevent malfunction of the fire grates 110, 120.
While the exemplary embodiments have been shown and described, it will be understood by those skilled in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

What is claimed is:

1. A fire grate type incineration apparatus, which includes movable fire grates and fixed fire grates alternately arranged in a step pattern and incinerates waste input thereto while moving the waste toward a discharge hole by the operation of the movable fire grates,

wherein a channel is formed in the fixed fire grates so that a coolant cools the fixed fire grates while flowing along the channel, and air introduced into the movable fire grates is supplied into the incineration apparatus after cooling the fire grates through an exhaust hole formed in the movable fire grates, and

wherein the movable fire grates or the fixed fire grates located to connect each other in the lateral direction of the same level have steps at sides thereof so as to be engaged with another movable fire grate or fixed fire grate at the sides thereof.

2. The fire grate type incineration apparatus according to claim 1, wherein a channel tube is formed in the front end of the fixed fire grate toward the inside of the fire grate type incineration apparatus to which waste is continuously input, and the channel tube is surrounded by a shield plate.

3. The fire grate type incineration apparatus according to claim 2, wherein an inlet tube and an outlet tube are formed at the rear end of the fixed fire grate, and the inlet tube and the outlet tube are connected to the channel tube.

4. The fire grate type incineration apparatus according to claim 1, wherein a shield plate is formed at the upper surface of the fixed fire grate.

5. The fire grate type incineration apparatus according to claim 2, wherein a shield plate is formed at the upper surface of the fixed fire grate.

6. The fire grate type incineration apparatus according to claim 3, wherein a shield plate is formed at the upper surface of the fixed fire grate.

7. The fire grate type incineration apparatus according to claim 1, wherein an exhaust hole is formed at the front end of the movable fire grate toward the inside of the fire grate type incineration apparatus to which waste is continuously input, and air introduced into the movable fire grate is preheated and supplied into the fire grate type incineration apparatus through the exhaust hole.

8. The fire grate type incineration apparatus according to claim 4, wherein the shield plate is made of chrome steel or ceramic material.

9. The fire grate type incineration apparatus according to claim 5, wherein the shield plate is made of chrome steel or ceramic material.

10. The fire grate type incineration apparatus according to claim 6, wherein the shield plate is made of chrome steel or ceramic material.