JP4090448B2 - Incinerator - Google Patents

Description

  The present invention relates to an incinerator in which a cooling chamber and a combustion chamber are vertically communicated with each other in a narrow portion, and an incinerator in which the combustion chamber is divided into a recombustion chamber and a primary combustion chamber by a throttle portion.

  An incinerator in which a cooling chamber for cooling combustion exhaust gas and a combustion chamber are vertically communicated with each other at a narrow portion is usually provided with an enlarged diameter portion that expands upward at the lower portion of the cooling chamber that is continuous with the upper portion of the narrow portion. (For example, refer to Patent Document 1). For this reason, a swirling flow that flows downward along the inclined wall surface of the enlarged diameter portion is generated around the rising flue gas flow, and dust in the flue gas to be cooled is caught in this swirl, and Adheres to an inclined wall. When the dust adhering to the inclined wall surface of the enlarged diameter portion accumulates in this way, the smooth flow of the combustion exhaust gas is hindered, and the accumulated dust falls into the lower combustion chamber and the combustion in the combustion chamber is also inhibited. There's a problem.

  As a means for preventing dust from adhering to the wall surface of the cooling chamber that cools the high-temperature exhaust gas such as combustion exhaust gas, the temperature control tower (cooling chamber) into which the high-temperature exhaust gas is blown from above, along the inner wall of the temperature control tower In some cases, cooling gas injection means for injecting cooling gas is provided below (see, for example, Patent Document 2). Patent Document 2 also proposes that the cooling gas is injected obliquely downward so that the cooling gas along the inner wall of the temperature control tower forms a downward swirling flow.

  On the other hand, for incinerators such as municipal waste, in order to reduce dioxins and carbon monoxide in the combustion exhaust gas, the combustion chamber is divided into a recombustion chamber and a primary combustion chamber at the upper and lower sections, and radiation transmission is performed. Many are used which are intended to increase the temperature in the furnace by increasing the hot surface and to increase the residence time in the furnace by wrapping in combustion gas. Such an incinerator is usually provided with a diameter-expanding part that expands upward in the lower part of the recombustion chamber that is continuous with the upper side of the throttle part (for example, see Patent Document 3). Patent Document 3 proposes a recombustion chamber provided with a tertiary combustion chamber in addition to the secondary combustion chamber.

Japanese Patent No. 2777482 (page 3, Fig. 1) JP 2001-276547 A (page 3-7, FIG. 1-2) JP-A-7-91631 (page 3-5, FIG. 1)

  In order to prevent dust from adhering to the inclined wall surface of the enlarged diameter portion of the cooling chamber in an incinerator in which the cooling chamber and the combustion chamber are vertically communicated with each other in a narrow portion as described in Patent Literature 1, It is conceivable that the cooling gas is injected upward or obliquely upward along the inclined wall surface of the enlarged diameter portion by applying the means described in Document 2, but is injected so as to prevent the adhesion of dust. In order to cover the inclined wall surface with the cooling gas, there is a problem that a large amount of cooling gas is required. When the amount of the cooling gas is increased in this way, the amount of exhaust gas also increases, and there is a problem that the exhaust gas treatment facility is enlarged.

  On the other hand, in an incinerator in which a combustion chamber as described in Patent Document 3 is divided into a recombustion chamber and a primary combustion chamber in the upper and lower portions by a throttle portion, the diameter of the recombustion chamber on the upper side of the throttle portion is reduced by the cooling chamber. Similar to the enlarged diameter portion of the chamber, a vortex flowing downward along the inclined wall surface of the enlarged diameter portion is generated, and dust in the combustion gas is caught in the vortex and adheres to the inclined wall surface of the enlarged diameter portion. The dust adhering to the inclined wall surface of the enlarged diameter portion also hinders the smooth flow of the combustion gas when it accumulates, and the accumulated dust falls into the primary combustion chamber below, which hinders combustion in the primary combustion chamber. is there.

  Moreover, in the upper part of the primary combustion chamber below the throttle part, the melted low melting point substance in the fly ash adheres to the wall surface. The low melting point material adhering to the wall surface grows into a granular shape or a needle shape to become a so-called clinker, and there is a problem that the smooth flow of the combustion gas is hindered and the radiation efficiency of the wall surface is reduced.

  Accordingly, the first problem of the present invention is to prevent dust from adhering to the inclined wall surface of the enlarged diameter portion of the cooling chamber, targeting an incinerator in which the cooling chamber and the combustion chamber are vertically communicated with each other at a narrow portion. is there. Further, the second problem of the present invention is that the dust adheres to the inclined wall surface of the recombustion chamber diameter-expanded portion for an incinerator in which the combustion chamber is divided into a recombustion chamber and a primary combustion chamber by a throttle portion. The third problem is to prevent the clinker from adhering to the upper wall surface of the primary combustion chamber.

  In order to solve the first problem, the present invention is configured such that a cooling chamber for cooling combustion exhaust gas and a combustion chamber are vertically communicated with each other at a narrow portion, and an upper side is provided at a lower portion of the cooling chamber connected to the upper side of the narrow portion. In the incinerator provided with the enlarged diameter portion that expands toward the inner diameter, a configuration is adopted in which the enlarged diameter portion of the cooling chamber is provided with an air ejection nozzle that forms a substantially horizontal swirling air flow along the inclined wall surface.

  That is, by providing an air jet nozzle that forms a substantially horizontal swirling air flow along the inclined wall surface in the expanded diameter portion of the cooling chamber, the swirling air flow is applied to the inclined wall surface of the expanded diameter portion of the cooling chamber with a small amount of air ejection. So that dust can be prevented from sticking to the inclined wall.

  In order to solve the second problem, the present invention has a combustion chamber that is divided into a recombustion chamber and a primary combustion chamber at the upper and lower portions by a constricted portion, and a lower portion of the recombustion chamber connected to the upper side of the constricted portion. In an incinerator provided with a diameter-expanding portion that expands to the side, a configuration in which an air ejection nozzle that forms a substantially horizontal swirling air flow along the inclined wall surface is provided in the diameter-expanding portion of the recombustion chamber did.

  That is, by providing an air ejection nozzle that forms a substantially horizontal swirling air flow along the inclined wall surface in the enlarged diameter portion of the recombustion chamber, the recombustion chamber can be used with a small amount of air ejection as in the first problem. The inclined wall surface of the enlarged diameter part is covered with a swirling air flow so that dust can be prevented from adhering to the inclined wall surface.

  By providing the air ejection nozzle above the center of the height of the enlarged diameter portion, it is possible to more effectively prevent dust from adhering to the inclined wall surface of the enlarged diameter portion of the cooling chamber or the recombustion chamber. Can do. In other words, the vortex that entrains the dust mentioned above collides with the inclined wall surface at the upper part of each enlarged diameter portion and turns downward, so that by providing the air ejection nozzle above the center of the height of the enlarged diameter portion, At the site where the dust inside collides with the inclined wall surface, the substantially horizontal swirling air flow can be made strongest.

  In order to solve the third problem, the present invention provides a primary combustion chamber connected to a lower side of the throttle portion in an incinerator in which the combustion chamber is divided into a recombustion chamber and a primary combustion chamber by a throttle portion. The structure which provided the air ejection nozzle which forms a substantially horizontal swirling air flow along the wall surface was employ | adopted for the upper part of this.

  That is, by providing an air jet nozzle that forms a substantially horizontal swirling air flow along the wall surface at the upper part of the primary combustion chamber connected to the lower side of the throttle part, the wall surface of the upper part of the primary combustion chamber can be reduced with a small amount of air jet. Covered with a swirling air flow to prevent clinker from adhering to the wall surface.

  By setting the ejection speed of the air ejected from the air ejection nozzle to 30 m / second or more, dust adheres to the inclined wall surface of the cooling chamber or the recombustion chamber, and clinker adheres to the upper wall surface of the primary combustion chamber. Can be reliably prevented. The reason why the air flow rate is 30 m / sec or more is that the viscous resistance to air flow is higher in high-temperature fields such as cooling chambers, re-combustion chambers, and primary combustion chambers, and the adhesion of dust and clinker is ensured. This is because it has been confirmed by actual machine experiments that such a high air ejection speed is necessary to prevent this.

  The incinerator in which the cooling chamber and the combustion chamber according to the present invention communicate vertically with a narrow portion forms a substantially horizontal swirling air flow along the inclined wall surface in the enlarged diameter portion of the cooling chamber connected to the upper side of the narrow portion. Since the air jet nozzle is provided, it is possible to cover the inclined wall surface of the enlarged diameter portion of the cooling chamber with the swirling air flow with a small amount of air ejection, and to prevent dust from adhering to the inclined wall surface.

  An incinerator in which a combustion chamber according to the present invention is divided into a recombustion chamber and a primary combustion chamber in the upper and lower portions by a throttle portion is substantially horizontal along the inclined wall surface of the enlarged diameter portion of the recombustion chamber connected to the upper side of the throttle portion. Since the air ejection nozzle that forms a simple swirling air flow is provided, the inclined wall surface of the recombustion chamber diameter-enlarged portion can be covered with the swirling air flow with a small amount of air ejection, and dust can be prevented from adhering to the inclined wall surface.

  By providing the air ejection nozzle above the center of the height of the enlarged diameter portion, it is possible to more effectively prevent dust from adhering to the inclined wall surface of the enlarged diameter portion of the cooling chamber or the recombustion chamber. .

  The incinerator in which the combustion chamber according to the present invention is divided into a recombustion chamber and a primary combustion chamber in the upper and lower portions by the throttle portion is a substantially horizontal swirl along the wall surface at the upper portion of the primary combustion chamber connected to the lower side of the throttle portion. Since the air jet nozzle that forms the air flow is provided, the wall surface of the upper part of the primary combustion chamber can be covered with the swirling air flow with a small air jet amount, and the clinker can be prevented from adhering to the wall surface.

  By setting the ejection speed of the air ejected from the air ejection nozzle to 30 m / second or more, dust adheres to the inclined wall surface of the cooling chamber or the recombustion chamber, and clinker adheres to the upper wall surface of the primary combustion chamber. Can be reliably prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This incinerator is of a fluidized bed type, and as shown in FIG. 1, the combustion chamber is divided into a recombustion chamber 2 and a primary combustion chamber 1 by a constricted portion 3 so as to cool the combustion exhaust gas. However, the narrow part 5 communicates with the recombustion chamber 2 vertically. The primary combustion chamber 1 is provided with an incineration inlet 6 and a primary combustion air supply port 7, and the recombustion chamber 2 is provided with a secondary combustion air supply port 8. Moreover, the cooling chamber 4 is provided with cooling water injection ports 9 for cooling the combustion exhaust gas in a plurality of stages. A combustion residue discharge port 10 is provided at the bottom of the primary combustion chamber 1, and a cooled combustion exhaust gas discharge port 11 is provided at the ceiling of the cooling chamber 4.

  As shown in FIGS. 2 (a) and 2 (b), a lower portion of the cooling chamber 4 connected to the upper side of the narrow portion 5 is provided with an enlarged diameter portion 12 that expands upward, and the height of the enlarged diameter portion 12 is increased. An air ejection nozzle 13 that forms a horizontal swirling air flow along the inclined wall surface 12a is provided at a position above the center. The air ejection nozzles 13 are provided at two positions in a horizontal plane with a phase of 180 °, and a portion of dust (not shown) that is entrained in the vortex A that flows downward along the inclined wall surface 12a collides with the inclined wall surface 12a. Thus, the strongest swirling air flow is formed. In addition, the jet speed of the air from each of the air jet nozzle 13 and each of the air jet nozzles 15 and 16 described later is set to 30 to 40 m / sec.

  As shown in FIG. 3 and FIG. 4A, a diameter-expanding portion 14 that expands upward is provided at the lower portion of the recombustion chamber 2 that is connected to the upper side of the throttle portion 3. An air ejection nozzle 15 that forms a horizontal swirling air flow along the inclined wall surface 14a is provided at a position above the center. The air ejection nozzles 15 are provided at four locations in a 90 ° phase in the horizontal plane, and the portion of the dust (not shown) that is entrained in the vortex B that goes downward along the inclined wall surface 14a collides with the inclined wall surface 14a. Thus, the strongest swirling air flow is formed. The air jet nozzles 13 are provided at two locations with a phase of 180 °, whereas the air jet nozzles 15 are provided at four locations with a phase of 90 °. This is because the degree of diameter expansion is steep and the strength of the vortex B is stronger than the vortex A.

  As shown in FIG. 3 and FIG. 4 (b), an air ejection nozzle 16 that forms a horizontal swirling air flow along the wall surface 1 a is provided at the upper part of the primary combustion chamber 1 that continues to the lower side of the throttle portion 3. In the horizontal plane, it is provided at two positions with a phase of 180 °. This swirling air flow prevents the low melting point material melted in the fly ash from adhering to the wall surface 1a of the clinker where it grows in the form of particles or needles.

  In the above-described embodiment, the combustion chamber is divided into the recombustion chamber and the primary combustion chamber vertically by the throttle portion, and the cooling chamber is communicated with the recombustion chamber vertically by the narrow portion. The incinerator according to the present invention has a narrowed cooling chamber that communicates vertically with one combustion chamber, or there is no communicating cooling chamber, and the combustion chamber moves vertically between the recombustion chamber and the primary combustion chamber at the throttle. It can also be used for the sectioned air, and the air that forms a horizontal swirling air flow independently on the narrowed part, the enlarged diameter part on the upper side of the throttle part, and the upper part of the primary combustion chamber on the lower side of the throttle part. An ejection nozzle can also be provided.

Longitudinal sectional view showing an embodiment of an incinerator a is a longitudinal sectional view showing the vicinity of the narrow portion of FIG. 1, and b is a sectional view taken along the line IIb-IIb of a. Longitudinal sectional view showing the vicinity of the throttle part in FIG. a and b are sectional views taken along lines IVa-IVa and IVb-IVb in FIG. 3, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Primary combustion chamber 1a Wall surface 2 Recombustion chamber 3 Restriction part 4 Cooling chamber 5 Narrow part 6 Input port 7, 8 Supply port 9 Injection port 10, 11 Discharge port 12 Expanded part 12a Inclined wall surface 13 Air ejection nozzle 14 Expanded part 14a Inclined wall surfaces 15 and 16 Air ejection nozzle

Claims (5)

  In an incinerator in which a cooling chamber for cooling combustion exhaust gas and a combustion chamber are vertically communicated with each other in a narrow portion, and a diameter-expanding portion that expands to the upper side is provided at a lower portion of the cooling chamber that is continuous with the upper side of this narrow portion. An incinerator characterized in that an air jet nozzle that forms a substantially horizontal swirling air flow along an inclined wall surface is provided in the diameter-expanded portion of the cooling chamber.   In an incinerator in which a combustion chamber is divided into a recombustion chamber and a primary combustion chamber in the upper and lower portions by a throttle portion, and a diameter-expanding portion that expands to the upper side is provided at the lower portion of the recombustion chamber that is connected to the upper side of the throttle portion An incinerator characterized in that an air jet nozzle that forms a substantially horizontal swirling air flow along the inclined wall surface is provided in the enlarged diameter portion of the recombustion chamber.   The incinerator of Claim 1 or 2 which provided the said air ejection nozzle above the height center of the said enlarged diameter part.   In an incinerator in which the combustion chamber is divided into a recombustion chamber and a primary combustion chamber by a throttle, the swirling air flow is substantially horizontal along the wall surface above the primary combustion chamber connected to the lower side of the throttle. An incinerator characterized in that it is provided with an air ejection nozzle that forms a gas.   The incinerator according to any one of claims 1 to 4, wherein an ejection speed of air ejected from the air ejection nozzle is set to 30 m / second or more.

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