JP2003161417A - Clinker sticking preventive furnace wall structure in waste combustion furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clinker sticking preventive furnace wall structure in a waste combustion furnace which aiming prevents operational obstruction by sticking and growing of a clinker and requires less maintenance. <P>SOLUTION: This furnace wall structure lines a fire resistant heat insulating material 5 with a plurality of corrosion resistant heat resistant cast steel plates 1, and uniformizes the thickness distribution in a plane of the unit corrosion resistant heat resistant cast steel plate in a state of being fixed in contact to the fire resistant heat insulating material, and is characterized by having a plurality of fixing means 2, 3, and 4 fixed in contact to the fire resistant heat insulating material at least on the periphery of the unit corrosion resistant heat resistant cast steel plate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clinker adhesion preventing wall structure in a waste incinerator.

[0002]

2. Description of the Related Art In a waste incinerator that incinerates waste such as municipal solid waste to reduce its volume, and at the same time recovers energy and useful resources, components such as plastics that increase the combustion temperature have recently been treated. Further, in order to suppress the production of harmful substances such as dioxins generated by combustion, it is necessary to control the combustion temperature to operate at a high temperature. Due to these factors, in the internal structure of the incinerator, various problems have occurred with the conventionally used heat-oxidation-resistant furnace wall material.

FIG. 6 shows a stoker incinerator 41 as an example of the waste incinerator. The waste material 45 is supplied from the charging hopper, contacts the primary air 46 on the stoker 43, and is burned and thermally decomposed. Further, the vaporized combustion components come into contact with the secondary air 47 in the secondary combustion section 44 and are further burned, and the high temperature combustion exhaust gas is radiated by the heat recovery section 49 and discharged to the outside. The combustion residue (ash) falls into the receiving tank 48 and is taken out. Here, 42 is a furnace wall, which is composed of a fireproof / heat insulating material and a structural material that supports it.

FIG. 5 is an overall view showing the furnace wall of the stoker type combustion furnace. 31 is a part of the hopper, waste fuel is supplied from here, and is sent inside by a pusher 32 provided at the lower part of this part. Reference numeral 33 is a combustion section that burns on the stoker. 44 is the above-mentioned secondary combustion section,
Reference numeral 34 is an ash take-out portion where the still hot ash falls. 5
Is a refractory material that constitutes the furnace wall, and although not shown,
Actually, it is supported by a structural material and affixed to the inside (fire side). This refractory insulation changes depending on the temperature inside the furnace, but the most refractory material is silicon carbide ceramic brick.

When the combustion temperature exceeds 1000 ° C., the clinker (ash) produced by the combustion is melted, and the reaction is adhered and deposited on the surface of the furnace wall. This phenomenon is most noticeable near the melting point of the clinker, and above that, the oxidative wear of the furnace material itself becomes more severe. These phenomena may make operation impossible due to the growth of deposits, which causes obstacles such as faster consumption of refractory materials. Furthermore, such problems as a decrease in operating rate and an increase in maintenance costs have been brought about by stopping operation and repairing.

In order to improve these, a furnace wall structure in which a clinker is not attached and a cast steel plate that does not grow is lined is beginning to be adopted. Even in this case, the plate is deformed and the material is deteriorated depending on the usage conditions such as high temperature of the furnace. Due to burnout or destruction of the support structure, there is no choice but to limit the usable temperature conditions.

For example, in Japanese Patent Laid-Open No. 2000-199621, as shown in FIG. 7, ribs 53 made of heat-resistant cast steel material are used.
Disclosed is a furnace wall structure in which the attached plate 51 is fixed to the outer supporting structural member by a bolt 55 and a nut 56 extending from one point of the central boss 52. A heat-resistant and heat-insulating material such as heat-resistant brick is inserted between the inner plate 51 and the outer support structure 57, so that a spacer (pipe) 54 is interposed.

However, in such a structure, the heat is radiated from the inside and the heat is radiated from the outside, and the heat radiation from the boss portion or the rib portion is larger than that of the flat plate portion in the situation where the temperature gradient is severe. A significant temperature gradient occurs. Therefore, thermal stress is generated in the plate surface, compression is applied inside and tensile stress is applied outside. In addition, the strength changes due to high temperature, and the plate bends violently inward. This phenomenon is
This was also confirmed by the results of thermal stress analysis by the inventors. The protective plate in such a state could no longer fulfill the role of protection.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and it is a clinker in a waste combustion furnace for the purpose of preventing the operation trouble due to clinker adhesion and growth and reducing maintenance. It is an object to provide an adhesion preventing furnace wall structure. More specifically, it is a furnace wall in which a plurality of corrosion-resistant heat-resistant cast steel plates are lined in a fire-resistant heat-insulating material, and the lining surface of the unit corrosion-resistant heat-resistant steel sheet in a state of being abutted and fixed to the fire-resistant heat-insulating material is the back surface side when heated. The purpose is to make the structure such that the heat distribution is almost uniform.

[0010]

A clinker adhesion preventing furnace wall structure in a waste incinerator according to the present invention is a furnace wall structure in which a plurality of cast steel plates are lined in a refractory heat insulating material, and fixed by abutting against the fire resistant heat insulating material. It is characterized in that it has a plurality of fixing means for abutting and fixing to the refractory heat insulating material at least around the unit cast steel plate in this state.

Furthermore, the clinker adhesion preventing furnace wall structure in the waste incinerator of the present invention is characterized in that the thickness distribution in the plane of the unit cast steel sheet is substantially uniform.

Further, the clinker adhesion preventing furnace wall structure in the waste incinerator of the present invention is characterized in that the cast steel plate is a corrosion-resistant heat-resistant cast steel plate and the refractory heat insulating material is substantially made of an inorganic material.

In the first place, by eliminating the geometrical features that bring about heat distribution, which is the cause of stress generation, the projection heat radiation parts such as bosses and ribs are removed, and a simple flat plate shape is used. It abuts on a fireproof heat insulating material such as a fireproof brick, and supports and fixes the surrounding area. This allows
There is no temperature distribution in the plate surface, and the heat that escapes from the fixing means causes a temperature gradient in the peripheral portion, but the generated stress is that the peripheral portion is open, so it escapes from the periphery, so the stress spreads to the surface. I can't reach it.

The thickness range of the unit corrosion-resistant heat-resistant cast steel sheet is approximately 10 mm to 50 mm, preferably 10 mm to 30 m.
m is good. At the lower limit, because the counterbore for arranging the fixing means is provided at the corner of the plate, that part becomes thinner, so it is a constraint from the problem of strength maintenance, and the upper limit is the weight of the unit corrosion-resistant heat-resistant cast steel plate is large. Therefore, it is a constraint due to construction problems. Although not particularly limited, the weight of the unit corrosion-resistant and heat-resistant cast steel sheet is about 20 kg, which is the limit for manual construction.

The portions of the pins, bolts, screws, etc. used for the fixing means exposed inside the furnace, that is, the heads of the pins, bolts, screws are preferably made of the same material as the liner, that is, the corrosion-resistant heat-resistant cast steel plate.

Further, in the furnace wall structure for preventing clinker adhesion in the waste incinerator of the present invention, the unit corrosion-resistant heat-resistant cast steel plate is square, and fixed to the fire-resistant heat insulating material at a plurality of points of symmetry on a square side. It is characterized by

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be exemplarily described below with reference to the drawings. However, the dimensions, shapes, materials, relative positions and the like of the products described in the present embodiment are not intended to limit the scope of the present invention thereto unless otherwise specified, and are merely illustrative examples. Not too much.

(Embodiment 1) FIG. 1 is a sectional view of an example of a clinker adhesion preventing furnace wall structure in a waste combustion furnace of the present invention. The left side is the inside of the furnace, and the right side is the outside. A plurality of unit corrosion resistant heat-resistant cast steel sheets 1 of the present invention are lined (contacted / fixed) on the refractory material 5. As shown in the figure, the supporting point has its peripheral portion supported by a pin 2 which is a fixing means. The pin 2 extends through the pipe (spacer) 4 penetrating the heat insulating material 6 and the refractory material 5 supported by the support structure 7, protruding leftward from the support structure 7, and screwed with the nut 3 to be tightened. ing.

(Embodiment 2) FIG. 2 shows an example in which fixing points are provided at a plurality of points on the sides of a square unit corrosion-resistant heat-resistant cast steel sheet. These means can be selected depending on the size of the plate and the situation of the fixing place. Is an example in which four sides are fixed, is an example in which four sides are fixed, and is an example in which two sides are fixed.

(Embodiment 3) FIG. 3 shows an example in which the fixing points are the four corners of a square unit corrosion-resistant heat-resistant cast steel plate, and a plurality of plates are fixed by using hexagon bolts and nuts as fixing means. The upper part is a schematic plan view, and the lower part is a schematic sectional view. Corrosion-resistant heat-resistant cast steel plate 1 provided with counterbores at which the heads of the bolts fit was provided at four corners, was brought into contact with refractory material 5 + heat insulating material 6, and pipes 4 were fixed to support structure 7 by hexagon bolts 62 and nuts 3 as spacers.

(Embodiment 4) FIG. 4 shows an example in which the fixing points are the four corners of a square unit corrosion-resistant heat-resistant cast steel plate, and a plurality of plates are fixed by using countersunk bolts and nuts as fixing means. The upper part is a schematic plan view, and the lower part is a schematic sectional view. Corrosion-resistant heat-resistant cast steel plate 1 provided with counterbores at the four corners to accommodate bolt heads
+ Abut on the heat insulating material 6, and with the countersunk bolt 72 and the nut 3,
The pipe 4 was fixed to the support structure 7 as a spacer.

[0022]

As described in detail above, by adopting such a furnace wall structure of the present invention, the unit corrosion-resistant heat-resistant cast steel sheet does not deform and stably protects the refractory material. It exhibits corrosion resistance and heat resistance, prevents clinker from adhering, and suppresses oxidative wear of the refractory material on the back surface.

[0023]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a clinker adhesion preventing furnace wall structure in a waste combustion furnace of the present invention.

FIG. 2 is a schematic plan view of an example in which fixing points of the present invention are provided at a plurality of points on a side of a square unit corrosion-resistant heat-resistant cast steel sheet.

FIG. 3 is a schematic plan view (upper part) and a schematic cross-sectional view (upper part) of an example in which the fixing points of the present invention are the four corners of a square unit corrosion-resistant heat-resistant cast steel plate, and a plurality of plates are fixed using hexagon bolts / nuts as fixing means. beneath)

FIG. 4 is a schematic plan view (upper part) and a schematic cross-sectional view (upper part) of an example in which the fixing points of the present invention are the four corners of a square unit corrosion-resistant heat-resistant cast steel plate, and a plurality of plates are fixed using countersunk bolts and nuts as fixing means. beneath)

FIG. 5 is a schematic view showing a furnace wall of a stoker type combustion furnace.

FIG. 6 A schematic diagram of a stoker type combustion furnace

FIG. 7 is a schematic plan and cross-sectional view showing ribs and bossed plates and supporting structures made of heat-resistant cast steel material disclosed in the prior art.

[Explanation of symbols]

1 Corrosion resistant heat resistant cast steel plate 2 pin 3 nuts 4 pipes (spacers) 5 Fireproof material 6 insulation 7 Support structure 31 hopper 32 pushers 33 Combustion part on the stoker 34 Ash removal section 41 stoker incinerator 42 Furnace wall 43 Stalker 44 Secondary combustion section 45 waste 46 primary air 47 Secondary air 48 receiving tank 49 Heat recovery unit 51 plates 52 Boss 53 ribs 54 Spacer (pipe) 55 volts 56 nuts 57 Support structure 62 hex bolt 72 Flat head bolt

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F27D 1/00 ZAB F27D 1/00 ZABD (72) Inventor Hiroshi Nishimura 5-34-6 Shiba, Minato-ku, Tokyo No. Mitsubishi Heavy Industries Environmental Engineering Co., Ltd. F-term (reference) 3K065 AA01 AB01 AC01 FA11 FB11 FC06 4K051 AB03 AB05 BB02 BB07

Claims (4)

[Claims] 1. A furnace wall structure in which a plurality of cast steel plates are lined in a fire-resistant heat insulating material, and the heat-resistant heat insulating material is abutted and fixed on at least the periphery of the unit cast steel plate. A clinker adhesion preventing furnace wall structure in a waste incinerator having a plurality of fixing means. 2. The clinker adhesion in a waste incinerator according to claim 1, wherein the unit cast steel sheet is rectangular and is fixed to the refractory heat insulating material at a plurality of points of symmetry on a rectangular side. Prevention furnace wall structure. 3. The clinker adhesion preventing furnace wall structure in a waste incinerator according to claim 1, wherein the in-plane thickness distribution of the unit cast steel sheet is substantially uniform. 4. The cast steel plate is a corrosion-resistant heat-resistant cast steel plate,
The clinker adhesion preventing furnace wall structure in a waste incinerator according to claim 1, wherein the refractory heat insulating material is made of an inorganic material.