JP4223459B2 - Furnace wall structure for preventing clinker adhesion in waste heat treatment furnace - Google Patents

Description

  The present invention is applied to furnace walls of incinerators, pyrolysis furnaces, melting furnaces and the like for heat treatment of waste, and prevents clinker from adhering to the inner wall of the furnace and preventing clinker adhesion in a waste heat treatment furnace. It relates to the wall structure.

In the treatment of general waste such as municipal waste, or industrial waste, the volume is reduced by heat treatment such as incineration, thermal decomposition, or melting treatment, and at the same time energy and useful resources are recovered. A heat treatment furnace is used. In recent years, components that increase the combustion temperature, such as high-calorie waste and plastics, are increasing in the treatment target, and it is necessary to operate with a high heat treatment temperature to suppress the generation of harmful substances such as dioxins generated by combustion. There is. For this reason, various problems have arisen in the internal structure of the furnace in the heat-resistant and oxidation-resistant furnace wall material such as a ceramic refractory material that has been conventionally used.
In these waste heat treatment furnaces, there is a problem that the ash melted in the furnace wall, the furnace outlet flue, and the like adheres in a lump due to the high temperature inside the furnace. In particular, when a high temperature portion is locally generated, an alkali metal salt having a low melting point contained in the waste is softened and melted and becomes a clinker and adheres to the inside of the furnace.

  Once the clinker is formed in the furnace, smooth waste disposal is hindered due to a decrease in the effective retention volume of the recombustion gas and uniform waste supply, and the treatment efficiency is lowered. Therefore, in order to prevent local temperature rise in the furnace, waste supply amount is adjusted, refractory walls that are easy to peel clinker are used on the furnace wall, furnace wall is water-cooled and air-cooled structure, and clinker is attached. Measures such as reducing it are taken. However, there is a problem that the furnace wall is easily damaged, and long-term continuous operation is difficult, and it is sometimes necessary to inspect the furnace at regular intervals to remove clinker deposits manually. It was. When the operation of the furnace is stopped and cleaning and maintenance are performed in this way, there are problems such as a decrease in operating rate and an increase in maintenance costs.

To improve these, a furnace wall structure lined with a cast steel plate that does not grow and grow with clinker is beginning to be adopted, but even in this case, depending on the use conditions such as high temperature of the furnace, deformation of the plate, short-term consumption due to accelerated oxidation, Burning or destruction of the support structure occurs, and the available temperature conditions must be limited.
For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2000-199621), as shown in FIG. 10, a plate 71 with a rib 73 made of a heat-resistant cast steel material is provided with a bolt 75 extending from one point of a boss 72 at the center. A furnace wall structure that is secured to the outer support structure with a nut 76 is disclosed. Since a heat-resistant and heat insulating material such as heat-resistant brick enters between the inner plate 71 and the outer support structural member 77, a spacer (pipe) 74 is interposed.

  However, such a structure is ignited on the inside and dissipated on the outside, and in a situation where the temperature gradient is severe, the heat dissipation from the boss or rib is larger than the flat plate, so a significant temperature gradient in the plate surface. Will occur. Therefore, thermal stress is generated in the plate surface, compression is applied on the inside, and tensile stress is applied on the outside. In addition, the strength changes due to high temperature, and the plate bends violently inside. This phenomenon was supported by the results of the inventors' thermal stress analysis. The protective plate in such a state was no longer able to play a protective role.

Therefore, in Patent Document 2 (Japanese Patent Laid-Open No. 2003-161417), as shown in FIGS. 8 and 9, a plurality of corrosion-resistant heat-resistant cast steel plates 61 are provided on the fire-resistant heat insulating material formed of the fire resistant material 66 and the heat insulating material 65. In the furnace wall structure lined with the refractory heat insulating material, the thickness distribution in the surface of the unit corrosion-resistant heat-resistant cast steel plate 61 in the state of being in contact with and fixed to the refractory heat insulating material is made uniform. A furnace wall structure having a plurality of fixing means for abutting and fixing to a wall is proposed. As an example, the fixing points by the fixing means can be the four corners of a rectangular cast steel plate 61 as shown in FIG. 9, and the fixing means can attach the cast steel plate 61 to the peripheral portion as shown in FIG. 8. The end of the pin 62 protruding through the pipe 64 penetrating the refractory heat insulating material is screwed with a nut 63 and fixed.
By adopting such a furnace wall structure, it is possible to prevent deformation of the cast steel sheet, to prevent the clinker from adhering to the furnace wall, and to suppress the oxidative depletion of the refractory material on the back surface.

JP 2000-199621 A JP 2003-161417 A

As described above, by lining a cast steel plate on the inner wall of the furnace, it is possible to obtain a furnace wall structure in which the clinker is difficult to adhere and grow. Further, by adopting the furnace wall structure as in Patent Document 2, a temperature difference is achieved. Therefore, a stable furnace wall structure can be obtained.
However, even with such a furnace wall structure, it is impossible to intentionally control the timing at which the clinker drops off, and the clinker deposited and deposited is allowed to fall naturally by its own weight. If the clinker can be forcibly removed immediately before the reactor is shut down for maintenance, it is desired to further reduce the load of the clinker removal work during maintenance.
Therefore, in view of the above-mentioned problems of the prior art, the present invention has a furnace wall structure in which clinker is difficult to adhere, and even when clinker is attached, the clinker is attached in a waste heat treatment furnace that can be forcibly removed. It aims at providing a prevention furnace wall structure.

Therefore, in order to solve such a problem, the present invention is a furnace wall structure in which a plurality of steel plate is lined in a refractory heat insulating material, in a state of being penetrated by the refractory heat insulating material and fixed in contact with the refractory heat insulating material. In a clinker adhesion preventing furnace wall structure in a waste heat treatment furnace provided with a plurality of fixing means for abutting and supporting the steel material plate at least around the unit steel material plate,
Among the fixing means, at least one fixing means located around one unit steel plate has a displacement member that displaces the fixing means in the penetration direction of the refractory heat insulating material by an impact force from outside the furnace. Features.

According to the present invention, the steel plate is formed into a simple flat plate shape that eliminates the shape feature that causes the heat distribution that is the cause of stress generation, and the periphery thereof is supported and fixed by the fixing means. Since the distribution is eliminated, the steel plate can be stably fixed.
Further, according to the present invention, the clinker attached to the steel plate is forcibly configured by including a displacement member that displaces the fixing means in the penetration direction of the refractory heat insulating material by an impact force from outside the furnace. Can be dropped. That is, when the clinker is attached, an impact is applied to the fixing means from outside the furnace, and the fixing means is pushed into the furnace, so that the clinker is pushed out and removed, or an impact force is applied to the tip of the fixing means or the The clinker can be removed by propagating to a steel plate. Thereby, for example, the clinker can be forcibly removed immediately before maintenance, and the safety of maintenance work can be ensured. In addition, since the clinker can be removed even when the furnace is in operation, stable furnace operation and improved maintainability can be expected.
The steel plate is a steel plate having a corrosion resistance and heat resistance, which is processed into a flat plate by various methods such as rolling, forging, drawing or casting, and is a cast steel plate produced by casting. It is preferable.

Further, the fixing means includes the displacement member, a shaft member that penetrates the refractory heat insulating material, a heat-resistant support member that is provided at a furnace inner end of the shaft member and supports the steel plate, and the shaft member. A shaft fixing member that is provided outside the furnace on the other end side and fixes the shaft member,
The displacement member is an elastic member interposed between the fireproof heat insulating material and the shaft fixing member.
For example, a coil spring, a spring washer, a cup spring or the like can be used as the elastic member. According to the present invention, the steel plate can be firmly supported and fixed as long as no impact is applied to the fixing means from the outside, and the furnace wall structure can be manufactured at low cost.

Further, the fixing means includes the displacement member, a shaft member that penetrates the refractory heat insulating material, a heat-resistant support member that is provided at a furnace inner end of the shaft member and supports the steel plate, and the shaft member. A shaft fixing member that is provided outside the furnace on the other end side and fixes the shaft member,
The displacement member is a detachable spacer interposed between the fireproof heat insulating material and the shaft fixing member.
In the present invention, when removing the clinker, by removing the spacer from the fixing means, a displacement allowance of the fixing means can be secured, and the fixing means can be easily moved. By adopting such a configuration, the steel plate can be firmly supported and fixed as long as no impact is applied to the fixing means from the outside, and the furnace wall structure can be manufactured at low cost.

Furthermore, it is preferable to provide a gap between the shaft member and the refractory heat insulating material so that the fixing means is rotationally displaced in the axial circumferential direction of the shaft member.
Thus, by making the fixing means pivotable in the axial circumferential direction, the clinker attached to the furnace wall can be pushed out while rotating the fixing means, and even a clinker attached firmly can be easily obtained. Can be removed.

Further, the fixing means is provided with temperature detecting means for detecting the furnace wall temperature.
This is because if the clinker adheres to the inner wall of the furnace and grows, the furnace wall temperature decreases. Therefore, the temperature detection means is provided in the fixing means and the temperature of the furnace wall is monitored so that the clinker adhesion state can be grasped. Therefore, when the furnace wall temperature decreases, it is determined that the clinker is attached, and the clinker is removed by the fixing means. As a result, the clinker removing operation can be performed at an appropriate time.

Further, a water injection nozzle is provided in the heat-resistant support member, and water is injected into the furnace.
In the present invention, water is supplied into the clinker attached to the furnace wall by injecting water into the furnace from the water injection nozzle. When this water rapidly expands in volume due to the high temperature atmosphere in the furnace, the clinker attached to the furnace wall can be crushed and peeled off and easily removed.

As described above, according to the present invention, the steel plate is formed in a flat plate shape whose periphery is supported and fixed by a fixing means, so that deformation of the steel plate can be prevented without causing a temperature difference, and stable. Thus, the steel plate can be fixed.
Furthermore, in the present invention, the clinker attached to the furnace wall is formed by configuring the fixing means to have a displacement member that displaces the fixing means in the penetration direction of the refractory heat insulating material by an impact force from outside the furnace. It can be removed by forcing off or forcibly removed by impact force. Accordingly, stable furnace operation and improvement in maintainability can be achieved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
The furnace wall structure of the present embodiment can be applied to a waste heat treatment furnace that heat treats general waste such as municipal waste or industrial waste. Examples of the waste heat treatment furnace include an incinerator, a pyrolysis furnace, and a melting furnace.

As an example of a waste heat treatment furnace to which the furnace wall structure of the present embodiment is applied, a stoker type incinerator 41 is shown in FIGS. In the stoker-type incinerator 41 shown in FIG. 6, the waste 45 is supplied into the furnace from the charging hopper, burns in contact with the primary air 46 on the stoker 43 of the primary combustion section located at the lower part of the furnace, and is thermally decomposed. . Further, the vaporized combustion component comes into contact with the secondary air 47 in the secondary combustion unit 44 and further burns, and the high-temperature combustion exhaust gas dissipates heat in the heat recovery unit 49 and is discharged outside.
The combustion residue (ash) falls into the receiving tank 48 and is taken out. The primary combustion section and the secondary combustion section 44 are surrounded by a furnace wall made of a refractory / heat insulating material 42 and a structural material that supports the fireproof / heat insulating material 42.

FIG. 7 is a view showing an example of a position where the clinker adhesion preventing furnace wall structure of the present embodiment is applied in the stoker type incinerator 41.
31 is a part of the waste charging hopper, from which waste is supplied and fed into the furnace by a pusher 32 provided at the bottom of this part. Reference numeral 33 denotes a primary combustion chamber that burns on the stoker, and 34 denotes an ash take-out section from which high-temperature ash falls. Reference numeral 30 denotes a furnace wall that employs the furnace wall structure according to the present embodiment.

The furnace wall structure of the furnace wall 30 is shown in FIGS. FIG. 1 is a schematic plan view (a) and a schematic cross-sectional view (b) of a clinker adhesion preventing furnace wall structure according to an embodiment of the present invention, and FIGS. 2 to 3 are clinker adhesion preventing furnaces according to an embodiment of the present invention. Examples 1 to 3 of the fixing means in the wall structure are shown, and FIG. 5 shows a fixing point of the clinker adhesion preventing furnace wall structure according to the example of the present invention, showing a square fixing (a), a four-side fixing (b), It is a figure which shows 2 side fixation (c), respectively.
As shown in FIG. 1 (a), the furnace wall structure of the present embodiment has a structure in which square steel plate 1 is planarly arranged on the wall surface of the furnace, and four corners of the steel plate 1 are abutted and supported by pins 3. It has become. As shown in FIG. 1 (b), the furnace wall has a refractory material 8 disposed inside the furnace, a heat insulating material 9 disposed outside the furnace, and the furnace outside of the heat resistant material 9 is covered with a support structure 10. Yes.

The steel plate 1 is abutted and fixed to the refractory material 8 by fixing means 2 including the pins 3. The fixing means 2 includes a pin 3 that abuts and supports the steel plate 1 at least around the steel plate 1, a shaft 4 that penetrates the refractory material 8, the heat insulating material 9, and the support structure 10. The shaft 4 includes a nut 6 that fixes an end of the shaft 4 protruding to the furnace outer side, and a displacement member 7 interposed between the nut 6 and the support structure 10.
The displacement member 7 has a function of displacing the fixing means 2 in the axial direction of the shaft 4 by an impact force from outside the furnace. Preferably, a slight gap is provided between the shaft 4 and the refractory material 8 and the heat insulating material 9 so that the fixing means 2 rotates in the axial direction of the shaft 4.

The fixing means 2 is pushed into the furnace by an impact force from the outside of the furnace, for example, a hammer or an air knocker, and removes the clinker adhering to the steel plate 1 or removes the impact on the pin 3 or the steel plate 1. The clinker can be forcibly removed by force propagation. At this time, when the fixing means 2 is rotated, the clinker adhered firmly by the turning force can be easily removed.
As described in the present embodiment, by making the steel plate 1 a flat plate with its periphery supported and fixed by the fixing means 2, it is possible to prevent deformation of the steel plate 1 without causing a temperature difference, It becomes possible to fix the steel plate 1 stably.
Furthermore, since the fixing means 2 includes the displacement member 7, the clinker attached to the furnace wall can be removed by dropping or forcibly removed by impact force, and stable furnace operation and maintainability can be achieved. Improvement can be achieved.

A fixing point of the fixing means 2 is shown in FIG. As shown in the figure, the fixing means 2 is preferably located at a plurality of symmetrical points around the steel plate 1. FIG. 5A shows a configuration in which fixing means are provided at the four corners of the square steel plate 1. At this time, at least one of the four fixing means positioned around one unit steel plate 1 is the fixing means 2 having the structure shown in the present embodiment. Other fixing means may have a structure in which the displacement member 7 is not provided. Of course, all the fixing means may be the fixing means 2 having the displacement member 7.
FIG. 5B shows a configuration in which fixing means are provided on the four sides of the steel plate 1, and FIG. 5C shows a configuration in which fixing means is provided on the two opposing sides of the steel plate 1. In any case, as in FIG. 5A, at least one of the fixing means positioned around one steel plate 1 is the fixing means 2 having the displacement member according to the present embodiment.

FIG. 2 shows a furnace wall structure having fixing means according to the first embodiment. In FIG. 2, the left side of the drawing is the inside of the furnace, and the right side is the outside of the furnace. The furnace wall has a structure in which a refractory material 8 is disposed inside the furnace, a heat insulating material 9 is disposed outside the furnace, and the outside of the heat resistant material 9 is covered with a support structure 10. A square steel plate 1 is abutted and fixed to the furnace inner surface of the refractory material 8. The steel plate 1 is supported by the fixing means 2 in contact with the periphery thereof.
The fixing means 2 includes a heat-resistant pin 3 that contacts and supports the steel plate 1, a shaft 4 that is fixed to the pin 3 and penetrates the refractory material 8 and the heat insulating material 9, and a pipe that surrounds the shaft 4. 5, a nut 6 screwed into the threaded end of the shaft 4 protruding to the outside of the furnace, and a coil spring 7 a interposed between the nut 6 and the support structure 10.

The coil spring 7a is configured to expand and contract by a predetermined length when an external force is applied. Preferably, the amount of displacement is around 5 to 10 mm. In addition to the coil spring 7a, any member may be used as long as it is extendable and displaceable in the axial direction. For example, an elastic member such as a spring washer, a cup spring, or a leaf spring can be used.
The fixing means 2 is pushed into the furnace by hitting the outer end of the shaft 4 with the hammer 11, and the clinker adhering to the furnace wall is removed by the pin 3 or removed by vibration of impact. It has become. The fixing means 2 is fixed as long as no impact force is applied from the outside.
The device that gives an impact to the fixing means 2 is not limited to the hammer 11, and any device that gives a mechanical impact may be used.
According to the present embodiment, the steel plate can be firmly supported and fixed, and the furnace wall structure can be manufactured at a low cost, unless an external impact is applied to the fixing means.

FIG. 3 shows a furnace wall structure having fixing means according to the second embodiment. Hereinafter, in the second embodiment and the third embodiment, the description of the same configuration as that of the first embodiment is omitted.
In FIG. 3, the fixing means 2 includes a pin 3 that abuts and supports the steel plate 1, a shaft 4 that is fixed to the pin 3 and penetrates the refractory material 8 and the heat insulating material 9, and surrounds the shaft 4. It comprises a pipe 5, a nut 6 screwed into a threaded end of the shaft 4 protruding to the outside of the furnace, and a spring washer 7 b interposed between the nut 6 and the support structure 10. .

The spring washer 7b has a structure that expands and contracts by a predetermined length when an external force is applied. Preferably, a plurality of spring washers 7b are provided so as to have a displacement of about 5 to 10 mm.
The fixing means 2 is pushed into the furnace by hitting the furnace outer end of the shaft 4 with an air knocker 12, and the clinker adhering to the furnace wall is removed by the pin 3 or removed by shock vibration. It has become. The fixing means 2 is fixed as long as no impact force is applied from the outside.
As the air knocker 12, a well-known one can be used. For example, the air knocker 12 has a casing 12a and a striking member 12b, and applies an impact force to the fixing means 2 by pressing the striking member 12b with compressed air.
According to the present embodiment, the steel plate can be firmly supported and fixed, and the furnace wall structure can be manufactured at a low cost, unless an external impact is applied to the fixing means.

FIG. 4 shows a furnace wall structure having fixing means according to the third embodiment. In FIG. 4, the fixing means 2 includes a pin 3 that contacts and supports the steel plate 1, a shaft 4 that is fixed to the pin 3 and penetrates the refractory material 8 and the heat insulating material 9, and surrounds the shaft 4. It comprises a pipe 5, a nut 6 that is screwed into a threaded end of the shaft 4 protruding to the outside of the furnace, and a spacer 7 c that is interposed between the nut 6 and the support structure 10.
The spacer 7c has a notch part in a part such as a U-shape, a U-shape, or a wedge shape, is detachable from the shaft 4, and has a length that gives a necessary amount of displacement. To have.

When removing the clinker adhering to the furnace wall, the spacer 7c is removed and the outer end of the shaft 4 is tapped with a hammer 11 to be pushed into the furnace, and attached to the furnace wall by the pin 3 The clinker is removed by dropping or by vibration of impact. The fixing means 2 is fixed by a spacer 7c during normal operation.
When the clinker is forcibly removed as in the present embodiment, the displacement of the fixing means 2 can be secured by removing the spacer 7c from the fixing means, and the fixing means 2 can be moved easily. be able to.

In this embodiment, a thermocouple 15 is provided inside the pin 3. The temperature of the furnace wall is monitored by the thermocouple 15, and when the temperature of the furnace wall decreases, it is determined that the clinker is attached, and the attached clinker is forcibly removed by applying an impact force to the fixing means 2. To.
As a result, the clinker removal process can be performed at an appropriate time. The means for detecting the temperature is not limited to the thermocouple 15.
Furthermore, it is good also as a structure which provided the water injection nozzle (not shown) in the inside of the said pin 3. As shown in FIG. This is because when the clinker is removed, when water is injected from the water injection nozzle into the furnace, and water is supplied to the gap inside the clinker, the water expands rapidly due to the high temperature atmosphere in the furnace. Then, the clinker adhering to the furnace wall can be peeled off and easily removed.

  According to the present embodiment, the furnace wall structure that has fire resistance and heat resistance and hardly adheres to the clinker can be applied, and thus can be applied to all waste heat treatment furnaces such as incinerators, pyrolysis furnaces, melting furnaces and the like. can do.

The plane schematic (a) and cross-sectional schematic (b) of the clinker adhesion prevention furnace wall structure which concern on the Example of this invention are shown. It is principal part sectional drawing which shows Example 1 of the fixing means in the furnace wall structure of FIG. It is principal part sectional drawing which shows Example 2 of the fixing means in the furnace wall structure of FIG. It is principal part sectional drawing which shows Example 3 of the fixing means in the furnace wall structure of FIG. It is a figure which shows the fixed point of the clinker adhesion prevention furnace wall structure which concerns on the Example of this invention, and shows 4 angle | corner fixation (a), 4 side fixation (b), and 2 side fixation (c), respectively. It is a schematic block diagram of a stoker type incinerator. It is a figure which shows the position where the clinker adhesion prevention furnace wall structure of a present Example is applied in FIG. It is the front schematic which shows the conventional clinker adhesion prevention furnace wall structure. It is sectional drawing which shows the clinker adhesion prevention furnace wall structure of FIG. It is the schematic of the plane and cross section which show the rib and bossed plate which were produced with the heat-resistant cast steel material currently disclosed by the prior art, and a support structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel plate 2 Fixing means 3 Pin 4 Shaft 5 Pipe 6 Nut 7 Displacement member 7a Coil spring 7b Spring washer 7c Spacer 8 Refractory material 9 Heat insulating material 10 Support structure 11 Hammer 12 Air knocker 15 Thermocouple

Claims (6)

A furnace wall structure in which a plurality of steel plates are lined on a refractory heat insulating material, wherein the steel plate is inserted at least around the unit steel plate in a state of being penetrated by the refractory heat insulating material and fixed in contact with the refractory heat insulating material. In the clinker adhesion prevention furnace wall structure in the waste heat treatment furnace provided with a plurality of fixing means for contacting and supporting,
Among the fixing means, at least one fixing means located around one unit steel plate has a displacement member that displaces the fixing means in the penetration direction of the refractory heat insulating material by an impact force from outside the furnace. A clinker adhesion prevention furnace wall structure in a waste heat treatment furnace. The fixing means includes the displacement member, a shaft member that penetrates the refractory heat insulating material, a heat-resistant support member that is provided at the front end inside the furnace of the shaft member and supports the steel plate, and the other end of the shaft member A shaft fixing member that is exposed outside the furnace on the side and fixes the shaft member,
The clinker adhesion preventing furnace wall structure in a waste heat treatment furnace according to claim 1, wherein the displacement member is an elastic member interposed between the refractory heat insulating material and the shaft fixing member. The fixing means includes the displacement member, a shaft member that penetrates the refractory heat insulating material, a heat-resistant support member that is provided at the front end inside the furnace of the shaft member and supports the steel plate, and the other end of the shaft member A shaft fixing member that is exposed outside the furnace on the side and fixes the shaft member,
The clinker adhesion preventing furnace wall structure in a waste heat treatment furnace according to claim 1, wherein the displacement member is a detachable spacer interposed between the refractory heat insulating material and the shaft fixing member.   4. The waste heat treatment furnace according to claim 2, wherein a gap is provided between the shaft member and the refractory heat insulating material so that the fixing means is rotationally displaced in the axial circumferential direction of the shaft member. Furnace wall structure to prevent clinker adhesion in   The clinker adhesion preventing furnace wall structure in a waste heat treatment furnace according to any one of claims 1 to 3, wherein the fixing means is provided with temperature detecting means for detecting the furnace wall temperature. 4. A furnace wall structure for preventing clinker adhesion in a waste heat treatment furnace according to claim 2, wherein a water injection nozzle is provided on the heat-resistant support member to inject water into the furnace.

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