JPH0828847A - Water wall structure of incinerator - Google Patents

Abstract

PURPOSE:To provide an incinerator water wall structure which is capable of preventing an anchor stud of a water tube from being deteriorated owing to heat in the incinerator and of keeping support surface over a long period of time. CONSTITUTION:An incinerator is constructed such that many water tubes 1, 1... are disposed on an incinerator wall or on the incinerator wall and a ceiling, and water flowing through the water tubes and heat produced in the incinerator are heat-exchanged for recovery of waste heat. In the incinerator, a cap 5 covering over the tip end 2a of an anchor stud 2 fixed to each water pipe 1 is formed with a heat insulating material having a lower heat conductivity than that of a protective layer 6 comprising a monolithic refractory covering the cap 5 therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water pipe wall structure of an incinerator.

[0002]

2. Description of the Related Art The furnace wall structure of a large-scale municipal solid waste incinerator is a water tube wall structure in which a large number of water tubes are arranged on the furnace wall and ceiling, and the heat generated in the furnace and the water tube interior are generated. Exhaust heat is used to generate steam by exchanging heat with the flowing water to generate electricity.

In order to efficiently conduct the heat in the furnace to the water pipe of the incinerator as described above, as shown in FIG. 3 which is a partial cross section of the furnace wall of the incinerator, the water pipes 1, 1 ... Caps 3 are attached to the tips of small pin-shaped anchor studs 2, 2 ...
3 is covered, and castables, plastic refractories, and other irregular shaped refractories are applied around the cap to form the protective layer 4, and consideration is given to prevent corrosion of the water pipe by combustion gas.

Since both the cap 3 and the protective layer 4 efficiently conduct the heat in the furnace to the water pipe 1 and enhance the cooling effect to prevent the incinerated ash from adhering to the surface as a clinker, it has been a conventional technical common sense. Mainly used is a silicon carbide material having a high thermal conductivity.

[0005]

In the conventional water pipe wall structure described above, however, the temperature of the surface (heated surface) of the protective layer 4 decreases due to the cooling action from the back of the protective layer 4, but conversely in the furnace. Of the heat is easily transferred to the tip of the anchor stud 2 through the cap 3, so that the tip of the anchor stud 2 deteriorates, loses its support force in a few years, and cannot protect the protective layer 4 for protection. There was the problem of causing layer 4 to drop out.

In view of this, the present invention provides a water tube wall structure of an incinerator which can prevent deterioration of the anchor stud due to heat in the furnace and can maintain the supporting force as the anchor stud for a long period of time. With the goal.

[0007]

As a means for solving the problems of the above-mentioned conventional techniques, the present invention is to provide a large number of water pipes on a furnace wall or a furnace wall and a ceiling part, and to supply water flowing in these water pipes. In an incinerator that recovers exhaust heat by exchanging heat with the heat generated in the furnace, a cap with a cap attached to the tip of an anchor stud fixed to the water pipe is coated with an irregular fire resistance It is characterized in that it is formed of a heat-resistant material having a lower thermal conductivity than the protective layer made of a material, preferably the cap is formed of chamotte or high alumina material, the protective layer carbonization of high thermal conductivity. It is composed of a silicon-based material.

[0008]

[Function] Since the cap material covering the tip of the anchor stud of the water pipe has a thermal conductivity lower than that of the irregular refractory material of the protective layer that is constructed so as to cover the periphery thereof, conduction through the protective layer Although the generated heat is well transferred to the water pipe, the tip of the anchor stud is insulated from the heat from the inner surface of the furnace and is cooled from the back side, so the temperature of the tip of the anchor stud is kept low, Damage to the tip due to heat is prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 shows a cross section of a part of a furnace wall of an incinerator according to the present invention, and FIG. 2 shows a front view of a part of the water pipes 1, 1 ... Similarly, a small pin-shaped anchor stud 2 having a predetermined pitch has its base fixed to the outer surfaces of the water pipes 1, 1 ... By electric welding, and its tip 2a is capped with caps 5 and 5. .

The cap 5 is a heat resistant material having a low thermal conductivity,
Preferably, it is made of chamotte or a material equivalent thereto.

The periphery of the caps 5, 5 ... Capped on the tip portion 2a of the anchor stud 2 is an amorphous refractory material having a thermal conductivity higher than that of the heat-resistant material constituting the cap 5, preferably. The protective layer 6 is formed by spraying castable silicon carbide or a material equivalent thereto.

In FIGS. 1 and 2, 7 is a fin connecting the water pipes 1 and 1.

Next, a water pipe panel imitating the water pipe wall structure according to the present invention and a conventional water pipe wall structure is prepared, and the water pipe panel is set in an electric furnace and heated, and the temperature rise and the anchor stud heat are applied. The deterioration situation was tested.

Table 1 shows the thermal conductivity of the materials used in the test, and Table 2 shows the test results. Table 1 Thermal Conductivity of Materials Used Present Invention Prior Art Silicon Carbide Castable 7.8 (w / mk °) 7.8 (w / mk °) Silicon Carbide Cap-12.5 Chamotte Cap 2.5- Table 2 Test Results Present Invention Prior Art Atmospheric Temperature (° C) 1200 1200 _{Heat Transfer Rate (Kcal / m} 2 _{hr) 50500 63000} Surface temperature of protective layer (° C) 1090 1070 Anchor stud tip temperature (° C) 690 870 Anchor stud tip deterioration state No change Approximately 3 mm from the tip (visual observation) Surface is deteriorated and its back 2 mm is discolored

As is clear from the above test results,
The surface temperature of the protective layer is almost the same as that of the present invention and the prior art, but the tip temperature of the anchor stud is significantly lower than that of the prior art by 180 ° C. in the present invention. No change was observed.

Therefore, since the material of the cap 5 capped on the tip of the anchor stud 2 of the water pipe 1 has a lower thermal conductivity than the material of the protective layer 6 which is constructed so as to cover the cycle, conduction through the protective layer 6 occurs. The heat inside the furnace is water pipe 1
The tip 2a of the anchor stud 2 while being efficiently transmitted to
Due to the heat insulation effect, the temperature of the tip portion 2a of the anchor stud 2 is kept low by cooling from the back surface, damage of the tip portion 2a due to heat is prevented, and it becomes possible to maintain the supporting force for a long time.

[0018]

As described above, according to the present invention, the cap around the tip of the pin-shaped anchor stud fixed to the water pipe in the water pipe wall structure of the incinerator is covered around it. Since it was made of a heat-resistant material whose thermal conductivity is lower than that of the protective layer made of irregular-shaped refractory, the heat conduction in the furnace stud is suppressed while the heat in the furnace is satisfactorily transferred to the water tube through the protective layer, As a result, the service life of the anchor studs supporting the protective layer can be significantly extended while efficiently recovering the heat generated in the furnace, and the supporting function of the protective layer can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a water pipe wall structure according to the present invention.

FIG. 2 is a front view showing a part of the water pipe.

FIG. 3 is a sectional view showing a conventional technique.

[Explanation of symbols]

 1 Water Pipe 2 Anchor Stud 2a Tip 3,5 Cap 4,6 Protective Layer

Claims (1)

[Claims] 1. An incinerator in which a large number of water pipes are arranged on a furnace wall or a furnace wall and a ceiling, and water flowing in the water pipes and heat generated in the furnace are heat-exchanged to recover exhaust heat. The cap capped on the tip of the anchor stud fixed to the water pipe is made of a heat-resistant material having a lower thermal conductivity than a protective layer made of an amorphous refractory covering the periphery of the cap. Water tube wall structure of incinerator.