JPS62721A - Dispersion nozzle in incinerator and the like - Google Patents

Abstract

PURPOSE:To prevent a damage of nozzle by a method wherein a fitted part between a ceramic member and a metallic member of a dispersion nozzle is tapered. CONSTITUTION:A ceramic member 15 constituting a dispersion nozzle and a metallic member 19 constituting two-split fastening member 19 are connected through their tapered portions at 20 and fastened through a ring 21, thereby a distribution of temperature generated in the ceramic member 15 is made uniform in the direction of thickness of the member, with the result that a concentration of stress is hardly performed. Further, even if non-uniform distribution of temperature is generated in the ceramic member 15 owing to non-uniform temperature such as a surrounding temperature etc. the smooth tapered surface 20 is contacted with the metallic member 19 of the ring-like fastening fitting, so that a concentration of stress due to a recess is hardly occurred and a damage of the member caused by an occurrence of excessive stress is hardly occurred.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a nozzle used for dispersing hot air, hot gas, etc. in incinerators, heating furnaces, etc. The present invention
Furthermore, the invention is not limited to such dispersion nozzles, but can be widely applied to general nozzles such as combustion nozzles and corrosion-resistant nozzles.

2. Description of the Related Art In incinerators for incinerating various chemical substances, various chemical substances ranging from strong acids to strong alkalis are produced by chemical reactions accompanying combustion. Furthermore, depending on the chemical substances handled in the heating furnace, the incinerator or the members constituting the heating furnace are exposed to a severe corrosive environment.

This will be explained using a fluidized bed incinerator as an example with reference to FIG.

In FIG. 2, an inner wall 2 made of a refractory material is provided inside a furnace body l. In addition, a hearth 3 is provided at the bottom of the furnace body 1.
is provided, and the upper surface of this hearth is finished with refractory mortar 4. A blowing chamber 5 and a hot air blowing port 6 are provided inside the hearth 3, and a plurality of sets of blowing pipes 7 and distribution nozzles 8 are provided above the hearth. A heavy oil spray nozzle 9 and a waste input nozzle 10 are attached to the lower part of the furnace body 1, respectively. Reference numeral 11 is fluid sand.

Next, the operation of such a fluidized bed incinerator will be explained.

At the start of operation, hot air at around 600°C is blown into the blowing chamber 5 from the hot air blowing port 6, and then supplied to the dispersing nozzle 8 through the blowing pipe 7, where it is distributed and blown, thereby dispersing the fluidized sand at the bottom of the furnace. 11 is made to flow between predetermined heights. After the inside of the furnace and the fluidized sand reach a predetermined temperature, heavy oil is fed into the fluidized sand 11 from the heavy oil spray nozzle 9 and ignited. After this ignition, the temperature of the hot air is 100 to 200°C. Further, after ignition and after the furnace reaches a steady state, waste is fed through the waste input nozzle 10 and incinerated.

Through such operations, the waste is efficiently and completely incinerated.

However, in the past, since a metal nozzle was used as the dispersion nozzle 8, it corroded after about half a year and had to be replaced with a new one.

Recently, in order to eliminate this inconvenience, a dispersion nozzle 15 made of ceramic with excellent corrosion resistance is provided with a hot air hole 16 extending vertically from the bottom to the top. A plurality of dispersion ports 17 are provided in the radial direction from the tip of this hot air hole. Further, a ring groove 8 is provided on the lower outer periphery of the ceramic dispersion nozzle 15, and a two-part fastening fitting 19 is fitted into this ring groove and integrated by means such as welding. The air pipe 7 is attached to the bottom of this two-part fastening fitting 19.
is attached by welding. Since the blast pipe 7 and the fastening fittings 19 are made of metal members, they are covered with a refractory mortar 4, and the tip of the ceramic dispersion nozzle 15 is made to protrude above the refractory mortar 4 of the hearth 3. There is.

Problems to be Solved by the Invention The ceramic dispersion nozzle 15 as described above has 80
Although it can withstand harsh corrosive environments at high temperatures of around 0°C, conventionally there was a problem in which the ring groove 18 was damaged at a high rate of about 30 inches.

This damage is thought to be caused by thermal shock caused by hot air at a temperature of approximately 600°C passing through the dispersion nozzle at room temperature during operation, or by thermal stress generated in the dispersion nozzle during operation, and the cause is limited to one of the two. This is thought to be due to structural factors.

Therefore, the present invention has been made with the object of preventing damage to ceramic dispersion nozzles due to such structural factors.

Means for Solving the Problems The present invention comprises a ceramic member that is installed in the hearth of an incinerator or the like, and has a leading end protruding above the hearth and a rear end fitted into a metal member. In the dispersion nozzle,
The portion of this ceramic member that engages with the metal member described above is tapered.

Function: According to the structure of the ceramic dispersion nozzle,
Since the thickness of the ceramic member is made uniform and there is no notch, stress concentration is less likely to occur, so damage to the nozzle is prevented.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to FIG. In FIG. 1, the same parts as those shown in FIG. 3 are given the same reference numerals, and detailed explanation thereof will be omitted.

According to this embodiment, the fitting of the ring groove structure of the conventional example shown in FIG. The metal member 19 and the ring 21 are welded together, and the air pipe 7 is attached to this ring by welding.

By adopting such a structure, the temperature distribution generated inside the ceramic member 15 of the dispersion nozzle becomes uniform in the thickness direction of the member, thereby reducing stress generated due to thermal expansion in the thickness direction. By acting uniformly, stress concentration is less likely to occur.

In addition, even if an uneven temperature distribution occurs inside the ceramic member 15 of the dispersion nozzle due to temperature non-uniformity such as ambient temperature, the gently tapered surface 20 allows the metal member 19 of the ring-shaped fastener to be Since they are in contact with each other, stress concentration due to the notch is less likely to occur, and damage to the member due to generation of excessive stress is less likely to occur.

Effects of the Invention As detailed above, the present invention provides a ceramic dispersion nozzle that is hard to break.

Regarding the effect of the present invention, the ceramic dispersion nozzle 15 shown in FIG. 1 was installed in a fluidized bed incinerator and used for one year, and it was confirmed that there was no corrosion or damage.

In this experimental example, the dispersion nozzle 15 is made of silicon nitride, has a density ratio (ratio to true density) of 97% or more, and a water absorption rate of 0%.
, the average bending strength of the standard sample is 50 kp/+ss
s+', the thermal shock value was ΔT = 600°C.

Further, the ring-shaped fastening fitting 19 is integrated by welding with the dispersion nozzle 15 incorporated therein, and the blower pipe 7 is attached to this by welding.

Furthermore, the operating conditions of the incinerator are that the temperature inside the incinerator is approximately 800°C;
The hot air temperature is approximately 600℃ at the start of operation and 100℃ during operation.
~200°C, and the flow rate at the dispersion port 17 was 60 m/s. For the first fluidized sand, spherical particles made of alumina with an average particle size of 100 μm were used.

When the weight increase/decrease of the ceramic dispersion nozzle 15 was measured before and after one year of operation, a weight decrease of about 1% per nozzle was observed.

This is thought to be due to erosion by the fluidized sand 11, but the function of the dispersion nozzle was not deteriorated and there was no change in the processing capacity of the incinerator.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a dispersion nozzle according to the present invention, and FIG.
The figure shows an example of a fluidized bed incinerator to which such a dispersion nozzle is installed, and FIG. 3 shows a conventional dispersion nozzle. 3. Hearth, 4. Hearth refractory mortar, 7. I pipe,
15--Dispersion nozzle (ceramic member), 16--hot air hole, 17--dispersion port, 19--fastening fitting (metal member)
, 20...Ci-ku fitting part, Fig. z Fig. 3

Claims (1)

[Claims] In a dispersion nozzle that is installed in the hearth of an incinerator or the like and is made of a ceramic member whose tip protrudes above the hearth and whose rear end is fitted into a metal member, the ceramic member and the metal member are connected to each other. A dispersion nozzle with a tapered fitting part.