JPS61195208A - Incinerator - Google Patents

Abstract

PURPOSE:To prevent transmitting heat of an incinerator inside in the form of radiation to a cooling part for incinerated exhaust gas by installing a hollow shield between an incinerator and the cooling part for exhaust gas installed at the upper part of the incinerator. CONSTITUTION:A cooling part 2 for incinerated exhaust gas is installed at the upper part of an incinerator 1 as one body with the incinerator and a hollow shield of which outside surface is covered with fire-resistant material is installed in a exhaust gas path between the incinerator 1 and the cooling part 2 for incinerated exhaust gas. By this structure, it is not necessary to over cool the inside of the incinerator 1 beyond necessity and also it is possible to use a simple incinerator composed of the incinerator 1 and exhaust gas cooling part 2 as one body for any waste to be incinerated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an incinerator that includes an incineration exhaust gas cooling section and an incinerator integrally.

[Conventional technology]

Conventionally, in an incinerator equipped with an incineration exhaust gas cooling section that cools the exhaust gas discharged from the incinerator, such as a waste heat boiler, an air cooler, and a water spray gas cooling room, the above incineration exhaust gas cooling section is a device independent from the incinerator. The concrete structure of the refractory is as shown in FIGS. 7 to 9, for example.

In the one shown in FIG. 7, an incinerator 20, a gas cooling chamber 22,
An air preheater 23, an electric precipitator 24, an induced blower 25, and a chimney 26 are sequentially connected by a duct.

The incinerator 20 is supplied with incineration materials, auxiliary combustion materials, and combustion air, and incombustible materials are discharged. Gas cooling chamber 22
In the combustion exhaust gas, cooling water that has passed through the injection water pressure pump 27 is injected into the combustion exhaust gas to cool the gas. Air preheater 2
3 preheats the combustion air sent from the forced air blower 28 and sends it to the incinerator 20, while cooling the exhaust gas. Ash separated from the combustion exhaust gas is removed from the gas cooling chamber 22 and the electrostatic precipitator 24.

Next, in the one shown in FIG.
6 are sequentially connected by ducts. The incinerator 20 is then discharged with incinerated materials, auxiliary combustion materials, and non-combustible materials preheated by steam air from the forced air blower 28 . Waste heat boiler 29
canned water is supplied to generate steam. Waste heat boiler 29
Ash in the exhaust gas is removed from the electrostatic precipitator 24.

Furthermore, in the one shown in FIG. 9, an incinerator 2o, an air preheater 23, a white smoke countermeasure heat exchanger 31, a cyclone 32, an induced fan 25, a scrubber 33, and a chimney 26 are sequentially connected by a duct. . Then, combustion air is supplied to the incinerator 20 through the air preheater 23 from the incineration materials, auxiliary combustion materials, and a forced air blower 28, and noncombustible materials are discharged.

The white smoke countermeasure fan 34 preheats the white smoke countermeasure air in the white smoke countermeasure heat exchanger 31 and then supplies it to the duct between the scrubber 33 and the chimney 26 .

The ash separated in the air preheater 23 and cyclone 32 is removed. Smoke washing water is injected into the scrubber 33.

As mentioned above, the incineration exhaust gas cooling units such as the waste heat boiler 29, the air preheater 23, and the water spray gas cooling chamber 22 that cool the exhaust gas discharged from the incinerator 2° are all connected to the incinerator 2.
Since it was installed separately from the incinerator 20, a huge installation area was required, and in addition, it was necessary to install the incinerator 20, the connecting duct, a support frame for the incineration exhaust gas cooling section 22, a walkway for inspection, etc. There have been problems such as pressure loss due to turbulence in the flow of exhaust gas in the flue such as the connecting duct, the incinerator outlet, and the inlet of the incineration exhaust gas cooling section, and the unavoidable accumulation and adhesion of dust.

Therefore, recently, as shown in FIG. 10, the exhaust gas cooling unit 21 is placed on top of the incinerator 20, and the ceiling of the freeboard part of the incinerator 20 is integrated with the incineration exhaust gas cooling unit 21. Advanced incinerators are being put into practical use.

As a result, the installation area of the equipment is completely unnecessary for the incineration exhaust gas cooling section, there is no connecting duct, the support frame is only for the incinerator, and the inspection walkway is only the one that protrudes from the incinerator and cooling section casing. In time, there is almost no turbulence in the incineration exhaust gas flow, and therefore the ventilation pressure loss of the incineration exhaust gas and the accumulation and adhesion of dust are completely eliminated.
Maintenance problems were reduced and the power required for ventilation was reduced.

[Problem that the invention seeks to solve]

However, when the incinerator 20 and the incineration exhaust gas cooling unit 21 are integrated, a large amount of heat is transferred from the incinerator 20 to the incineration exhaust gas cooling unit 21 in the form of radiation, and as a result, the temperature inside the incinerator 20 decreases. Although this is advantageous for some types of incineration, it is rather inconvenient for other types of incineration, and in some cases, such an integrated furnace cannot be used.

In other words, in the case of incinerated materials with a high calorific value, the cooling load on the furnace is reduced, and when a waste heat boiler or air preheater is used to cool the incineration exhaust gas, there is no need to cool the furnace. This is advantageous in that there is no need to increase the heat transfer area of the waste heat boiler or air preheater because the amount of heat that can be recovered is increased and a large amount of heat is transferred by radiation.

On the other hand, in the case of incinerated materials with a low calorific value, it is necessary to add or increase the amount of combustion aid in order to maintain the temperature required for cooling. If sufficient combustion is still not possible, the amount of unburned matter in the ash and exhaust gas may increase. Therefore, in such a case, it is common practice to not integrate the incinerator 20 and the incineration exhaust gas cooling unit 21, but to form them as separate and independent equipment, or to form them as modified pieces as shown in Fig. 11. Met. However, the first
The equipment shown in Figure 1 consists of an incinerator 20 and an incineration exhaust gas cooling section 2.
Even though 1 is integrated, the structure of the connection part is rather complicated, and the cooling of the incinerator by radiation heat transfer is the same as that in Figure 1O for the upper part of the incinerator, and the volume of the incinerator is Therefore, it was necessary to allow for some leeway.

The present invention solves the above-mentioned problems of the conventional ones, requires a small installation area, does not require a connecting duct, has a simple support frame and inspection walkway, and transfers heat from the incinerator to the incineration exhaust gas cooling section by radiant heat transfer. It is an object of the present invention to provide an incinerator in which a gas cooling section is integrated with the incinerator, and the inside of the incinerator is maintained at a necessary temperature by preventing the gas from moving.

[Means and operations for solving the problems] As a means for solving the above problems, the present invention provides an incinerator in which an incineration exhaust gas cooling section is integrally mounted on the upper part of the incinerator. It is an object of the present invention to provide an incinerator characterized in that a hollow shield whose outer surface is covered with a refractory material is provided in the exhaust gas flow path near the connection part with the incineration lid gas cooling part, and thereby, the incinerator It is possible to prevent radiant heat transfer from the incinerator to the exhaust gas cooling section, maintain the temperature inside the incinerator at a temperature depending on the material to be incinerated, and make it possible to use the incinerator for any kind of material to be incinerated.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the invention.

An incineration exhaust gas cooling unit 2 such as a gas cooling chamber, a waste heat boiler, or an air preheater is integrally mounted on the incinerator 1 . A single hollow shield 3 is installed laterally in the exhaust gas flow path near the connection between the incinerator 1 and the incineration exhaust gas cooling unit 2. The hollow shield 3 has a rectangular cross section and is open at one or both ends to allow free air circulation. The dimensions, shape, and arrangement of the hollow shield 3 are such that the heat inside the incinerator 1 is prevented from being transmitted to the incineration exhaust gas cooling unit 2 by radiation as much as possible, but it also prevents the outflow of the incineration exhaust gas and reduces pressure loss. shall be such that it will not occur.

FIG. 2 also shows a second embodiment.

Above the incinerator 1, there is an incineration exhaust gas cooling unit 2 similar to the above.
connected together. The hollow shields 3 are a large number of small, rectangular cross-sections, open at one or both ends, arranged at appropriate intervals and at the same height.

FIG. 3 shows a longitudinal cross-sectional view of the hollow shield shown in FIGS. 1 and 2. FIG.

As shown in the figure, both ends of the hollow shield 3 protrude from the casing 7 of the incinerator 1, and one or both end faces are open to the atmosphere. The hollow shield 3 is formed by applying a heat insulating material 5 and a fireproof material 6 around a hollow shield casing 4, thereby maintaining almost the same heat insulation properties and fire resistance as the incinerator wall.

In addition, in order to release the difference in thermal expansion between the incinerator casing 7 and the hollow shield casing 4, the hollow shield casing 4 has one end (the left end in the drawing) fixed, the other end free, and is covered with fireproof cloth such as asbestos. The expansion 8 is fixed by a band 9 to isolate the inside and outside of the furnace and prevent air and incineration exhaust gas from leaking.

Moreover, by making the hollow shield 3 hollow and opening one or both ends to the atmosphere, the temperature increase is suppressed by heat exchange with the atmosphere circulating inside. Therefore, like the incinerator wall, the refractory 6 of the hollow shield 3 is also protected by passing a heat insulating material 5 through the hollow shield casing 4 to radiate some heat. However, this hollow shield 3
It must be avoided that a large amount of heat within the incinerator 1 is dissipated to the outside through the incinerator.

It is desirable to use a material with a specific gravity of usually 1 to 3, such as a refractory brick, and as the heat insulating material 5, a material with a small specific gravity of 0.1 to 0.3, such as a ceramic heat insulating board or a heat insulating castable, is used.

When the hollow shield casing 4 is made of steel, the fireproof material 6
If the hollow shield casing 4 itself has a heat insulating effect and the temperature of the hollow shield casing 4 can be suppressed to 300° C., preferably around 200° C. or less, there is no need to provide any particular heat insulating material. If heat-resistant steel is used for the hollow shield casing 4, its temperature can also be increased further. Forced ventilation of the air within the hollow shield casing 4 is effective in suppressing the temperature of the hollow shield 3.

FIG. 4 shows another structure of the hollow shield 3. In FIG.

As in the embodiment shown in Fig. 1, the cross-sectional area of the hollow part is large;
Moreover, if the temperature difference between the hollow shield casing 4 and the incinerator casing 7 is small and the stress generated due to the difference in thermal expansion can be ignored, as shown in FIG.
and a hollow shield casing.

Note that the shape of the hollow shield 3 must be determined taking into account the possibility that dust will accumulate on it and the exhaust gas flow will be disturbed. It is preferable to narrow the width.

By having the above-described configuration, heat transfer by radiation from the incinerator 1 to the exhaust gas cooling unit 2 is almost prevented, even though the incinerator 1 and the incineration exhaust gas cooling unit 2 are integrally configured. , the thermal relationship can be severed in the same way as with the separate type shown in FIGS. 7 to 9.

FIG. 5 shows another embodiment.

In this embodiment, the hollow shield 3 is composed of a large number of hollow tubes installed in a staggered manner in the exhaust gas flow path near the exhaust gas cooling section 2 and the connection section in the upper part of the incinerator 1. In this embodiment, the radiation heat transfer from the incinerator I to the exhaust gas cooling section 2 is almost completely prevented.

FIG. 6 shows yet another embodiment, in which the incinerator 1 is a fluidized bed 1.
0 and a freeboard section 11.

A burner 12 is provided on the side wall of the incinerator 1, to which auxiliary combustion materials and a portion of combustion air are supplied. Most of the combustion air is supplied from below the fluidized bed 10, and after fluidization of the fluidized bed 10, the incineration material introduced from above is incinerated. In such a fluidized bed incinerator, the temperature of the fluidized bed IO is at least 5
It is essential for the operation of the incinerator 1 to maintain the temperature at 00°C or higher, preferably at 600°C or higher, and for this purpose, it is necessary to suppress the outflow of heat from the fluidized bed 1o as much as possible, especially in the case of incinerated materials with a low calorific value. Alternatively, increasing the inflow of heat leads to stabilization of combustion and a reduction in the amount of combustion aids used.

Therefore, the hollow shield 3 maintains a high temperature in the freeboard section 11, increases the flow of heat from the freeboard section 11 into the fluidized bed 10, and suppresses the outflow of heat from the fluidized bed 1o to the exhaust gas cooling section 2. This directly leads to improved incineration function and reduced fuel consumption, which is particularly effective.

The hollow shielding body 3 in FIGS. 5 and 6 above may have a structure as shown in either FIG. 3 or FIG. 4 depending on the circumstances.

〔Effect of the invention〕

According to the present invention, in an incinerator in which the incineration exhaust gas cooling section is integrally mounted on the upper part of the incinerator, it is easy to prevent the heat in the incinerator from being transmitted to the incineration exhaust gas cooling section in the form of radiation. As a result, it is now possible to use an incinerator with a simple structure that integrates the incinerator and exhaust gas cooling section for any type of incineration material, saving site space and simplifying the structure. This makes it possible to reduce exhaust gas pressure loss, reduce dust adhesion, etc., and has a significant effect on lowering construction costs, operating costs, and maintenance management.

[Brief explanation of the drawing]

1, 2, 5, and 6 are schematic side sectional views showing embodiments of the present invention, and FIGS. 3 and 4 are longitudinal sectional side views of the hollow shield in the above embodiments. Figure, Figure 7, Figure 8
FIG. 9 is a diagrammatic side sectional view of a conventional integrated incinerator. 1... Incinerator 2... Exhaust gas cooling unit 3... Hollow shield 4... Hollow shield casing 5... Heat insulating material 6... Refractory material 7... Casing 8... Expansion 9...Band 10...
Fluidized bed 11...Freeboard section 12...Burner
20...Incinerator 21...Exhaust gas cooling unit 22...Gas cooling room 23...Air preheater 24...Electric precipitator 25...Induced blower 26...Chimney 2
7. Injection water pressure pump 28. Forced blower 29.
・Waste heat boiler 30・・Air preheater 31・・Heat exchanger 32・・Cyclone 33・・Scrubber 34・・Fan for white smoke prevention. Figure 4 Figure 5

Claims (1)

[Claims] 1. In an incinerator in which an incineration exhaust gas cooling unit is integrally mounted on the upper part of the incinerator, a hollow space whose outer surface is covered with a refractory material is provided in the exhaust gas flow path near the connection between the incinerator and the incineration exhaust gas cooling unit. An incinerator characterized by being equipped with a shield.