JP2007240047A - Air blowing nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air blowing nozzle capable of easily performing maintenance when deformation or corrosion progresses, and elongating a service life of a nozzle main body in the air blowing nozzle for blowing the combustion air and the like from a furnace wall of a combustion melting furnace into the furnace. <P>SOLUTION: In this air blowing nozzle 3 disposed to generate swirl flow in the combustion melting furnace 1 where combustible components are burned and melted and discharged as molten slag, the air blowing nozzle 3 includes a nozzle main body 31 disposed at the circumference of the combustion melting furnace 1, an air introduction pipe 32 communicated with the nozzle main body 31, and an insertion pipe 33 opened at its both ends and movably inserted into the nozzle main body 31, and has a locking means 34 for fixing one of tips 36 of the insertion pipe 33 in a state of being projecting from the inner wall of the combustion melting furnace 1 into the furnace. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air blowing nozzle, and more particularly, an air blowing nozzle provided on a furnace wall of a combustion melting furnace that burns and melts combustible components and discharges them as molten slag to supply combustion air and the like into the furnace. It is about.

  Combusting combustible components such as pyrolysis gas and pyrolysis carbon obtained by pyrolyzing waste, such as general waste such as municipal waste and industrial waste such as waste plastic, and melting the generated combustion ash There is known a combustion melting furnace which is taken out as molten slag. In particular, in order to promote mixing of pyrolysis gas or pyrolysis carbon and combustion air, and to improve the collection rate of molten slag, a swirl flow is given to the combustion air blown from the furnace wall, and centrifugal force is applied. Fine combustion ash and molten slag are attached to the furnace wall and collected separately from the combustion exhaust gas. The molten slag adhering to the furnace wall flows down the wall surface and is discharged from a discharge port provided in the lower part of the combustion melting furnace for processing.

  However, when the molten slag flows down the furnace wall and reaches the opening of the air blowing nozzle arranged on the wall surface, it is rapidly cooled and solidified by the combustion air ejected from the opening, closing the air blowing nozzle, and the combustion air This will cause a problem in the supply.

For this reason, Patent Document 1 proposes that the tip of the blowing nozzle protrudes into the furnace and that the outer peripheral surface of the tip is covered with a refractory or special casting. However, there are practically no special castings that can withstand contact with the harsh in-furnace environment and molten slag, which have a strong oxidizing atmosphere with temperatures reaching 1100 ° C to 1400 ° C, and the useful life for practical use is It may be about one year, and the blowing nozzle itself is severely deformed and corroded. Therefore, since the combustion melting furnace is provided with a large number of air blowing nozzles per unit, enormous costs and labor are required for the repair described above.
Japanese Patent Laid-Open No. 11-173527

  An object of the present invention is to simplify maintenance when deformation or corrosion occurs in an air blowing nozzle for supplying combustion air or the like from a furnace wall of a combustion melting furnace into the furnace, and extend the life of the nozzle body. The object is to provide an air blowing nozzle.

  The air blowing nozzle of the present invention that achieves the above object is an air blowing nozzle that is disposed so as to cause a swirling flow in the combustion melting furnace that burns and melts combustible components and discharges them as molten slag. The air blowing nozzle includes a nozzle body disposed around the combustion melting furnace, an air introduction pipe communicating with the nozzle body, and an inner tube that is open at both ends and is movably inserted into the nozzle body. And a locking means for fixing one end of the inner tube so as to protrude from the inner wall of the combustion melting furnace into the furnace.

  The air blowing nozzle of the present invention comprises a nozzle body arranged around the combustion melting furnace, an air introduction pipe, and an internal intubation inserted so as to be movable therein. Of these, only the internal intubation projects into the furnace. Assembled. For this reason, only the intubation comes into contact with the molten slag. As a result, when the distal end of the intubation tube is deformed or corroded, only the distal end portion is removed by cutting or the like, the locking means of the intubation tube is released, and the projecting portion projects to the desired length. It can be repaired by moving it and maintenance is very easy. Further, since the nozzle body is not directly exposed to the combustion furnace, its deformation or corrosion can be suppressed and the life can be extended.

  In addition, by using a metal material having high thermal conductivity for the inner tube, the inner tube itself is always cooled by the supply air, so that the heat load can be reduced.

The present invention is described in detail below.
FIG. 1 is a side view illustrating a partial cross section in which an air blowing nozzle of the present invention is attached to a combustion melting furnace. In FIG. 1, the furnace wall of the combustion melting furnace 1 is composed of a refractory material 11 on the inner wall and a water-cooled wall 12 on the outer wall, and the molten slag s flows down the wall surface of the inner wall from the top to the bottom. The nozzle body 31 of the air blowing nozzle 3 is attached to a predetermined height of the combustion melting furnace 1 so as not to be directly exposed to the furnace. Further, the air introduction pipe 32 is connected to the nozzle body 31 so as to communicate with the inside. The end portion 37 of the air introduction pipe 32 is preferably constituted by a flange or the like, and a viewing window may be provided or another fluid introduction pipe may be added and connected as necessary.

  An inner tube 33 is movably inserted into the nozzle body 31 and the air introduction tube 32 at the start of use. Further, the inner insertion tube 33 is fixed to the nozzle body 31 and / or the air introduction tube 32 by the locking means 34 so that one end portion 36 thereof protrudes from the inner wall of the combustion melting furnace into the furnace. Both ends of the inner tube 33 are open, and the combustion air introduced from the combustion air inlet 35 of the air inlet tube 32 flows in from the opening end of the inner tube 33 on the air inlet tube 32 side and protrudes from the furnace wall. It spouts into the furnace from the inner intubation distal end portion 36. If the end of the open end of the inner tube 33 on the side of the air introduction tube 32 is cut obliquely, the combustion air passes without the flow path being blocked by a flange or the like on the side of the air introduction tube 32 facing the inner tube 33. It is easy and preferable.

  Since the air blowing nozzle of the present invention has a structure in which only the inner intubation 33 protrudes into the furnace, the inner intubation is mainly exposed to a harsh in-furnace environment, contacts with the molten slag, and is deformed or corroded. Therefore, the deformation or corrosion of the nozzle body can be suppressed and the life can be extended, and the frequency of major repairs such as replacement of the nozzle body can be reduced. Also, if the tip of the intubation is deformed or corroded, during periodic repair work, only such tip is removed by cutting, etc. Can be easily repaired by moving to a desired length, and maintenance costs and labor can be greatly reduced. In addition, when the intubation is severely deformed or damaged, or when the length is shortened, it is easy to replace the intubation.

  Here, a plurality of air blowing nozzles are arranged in the combustion melting furnace so as to cause a swirling flow in the melting and melting furnace, preferably as shown in FIG. It is good to arrange | position toward the tangent direction of the virtual circle centering on. For this reason, the air ejected from each air blowing nozzle 3b becomes a swirling flow and flows in the combustion melting furnace. For this reason, mixing of combustible components and combustion air is promoted to improve combustion efficiency, and fine ash and molten slag are adhered to the furnace wall by centrifugal force of the swirling flow to increase the collection rate of molten slag. It has improved.

  In the present invention, the length p for projecting the distal end portion 36 of the intubation tube from the inner wall of the combustion melting furnace is set so that the molten slag flowing down the furnace wall does not block the distal end portion of the intubation tube. Is preferred. Thus, by projecting the distal end portion of the inner intubation tube with a length p, the combustion air can be stably supplied without blocking the distal end portion of the inner intubation tube when the molten slag flows down. . Here, the protrusion length p is the shortest length when measured in parallel with the central axis of the intubation tube from the inner wall to the tip. Further, the end face of the distal end of the intubation tube may be cut substantially perpendicular to the central axis of the inner tube, but if it is cut slightly inclined toward the lower side of the furnace, it is preferable that the end surface is not easily blocked by the molten slag.

  The length of the intubation tube used in the present invention is preferably 10 to 20 times the length p that causes the tip of the intubation tube to protrude from the furnace wall.

  The locking means is not particularly limited as long as the inner tube can be fixed to the nozzle body and / or the air introduction tube, but a fixing bracket such as a bolt may be used. In addition, it is preferable to provide recesses or projections at predetermined intervals on the outer peripheral surface of the intubation tube, which is a measure of the protruding length p, and is preferable from the viewpoint of preventing the fall of the intubation tube.

  In the present invention, it is preferable that the nozzle body and / or the inner tube is made of a material having excellent heat resistance and corrosion resistance. Specifically, it is preferable that the nozzle body and / or the inner tube is made of a material selected from the group consisting of stainless steel, carbon steel, alloy steel, and cast iron steel, and stainless steel and alloy steel are particularly preferable.

  In addition, by configuring the inner tube from a metal material having a high thermal conductivity in this way, the inner tube itself is constantly cooled by continuing to supply combustion air, so that the heat load received from the harsh furnace environment is reduced. Can be reduced.

  The combustion melting furnace of the present invention is a combustion melting furnace provided with the air blowing nozzle described above, and has a nozzle group in which a plurality of air blowing nozzles are distributed and arranged around the combustion melting furnace at the same height, A combustion melting furnace having a plurality of nozzle groups at different heights is preferable.

  FIG. 2 schematically illustrates an outline of the configuration of an example of a combustion melting furnace provided with the air blowing nozzle of the present invention. In FIG. 2, the combustion melting furnace 1 burns and melts combustible components, causes the generated molten slag to adhere to the inner wall of the furnace, flows down, and discharges it from an outlet 9 provided at the bottom. The generated combustion exhaust gas flows from the bottom to the flue 8 and is discharged after appropriate exhaust gas treatment (not shown) such as waste heat utilization or dust collection.

  A fuel blowing nozzle 4 for supplying a combustible component such as pyrolytic carbon generated by a pyrolysis furnace (not shown) and a pyrolysis gas blowing nozzle 5 for supplying pyrolysis gas are also provided at the top 2 of the combustion melting furnace 1. Is provided. Moreover, the several air blowing nozzle is arrange | positioned as the air blowing nozzle group 3a, 3b, 3c disperse | distributed and arrange | positioned in the circumferential direction around the predetermined height of a combustion melting furnace. Specifically, a primary air blowing nozzle group 3a for supplying primary air a1 near the top 2 and a secondary air blowing nozzle group 3b for supplying secondary air a2 to the middle height of the combustion melting furnace 1, Below that, a tertiary air blowing nozzle group 3c for supplying the tertiary air a3 is provided. These air blowing nozzle groups 3a, 3b, and 3c are connected to the pushing blower 6 by the air supply line 7, and the flow rate is controlled by the valves 10a, 10b, and 10c so that combustion air is supplied. ing.

  Although the number of air blowing nozzle groups shown in FIG. 2 is three, the number of nozzle groups is not limited to this and is preferably 2 or more. Further, the number of air blowing nozzles constituting each nozzle group may be the same or different, and preferably 3 to 8 increases the mixing effect of the combustible component and the combustion air, Moreover, a stable swirling flow can be generated to improve the collection rate of molten slag.

And the primary air a1, the secondary air a2, and the tertiary air a3 for combustion blown into the combustion melting furnace 1 from the air blowing nozzle groups 3a, 3b, and 3c flow with necessary swirl and flow from 1100 to 1400. The combustible component supplied from the top of the tower is burned in a high temperature range of about 0 ° C., and the generated combustion ash is melted and adhered to the inner wall surface as molten slag.
When this molten slag flows down the inner wall of the combustion melting furnace, there is a possibility that it will be cooled and solidified around the air blowing nozzle, and in some cases, it is assumed that the opening at the tip of the intubation tube is blocked.

  In the present invention, the supply of combustion air from the air blowing nozzle may be intermittently interrupted. When the flow of combustion air having a low temperature is interrupted, the temperature of the air blowing nozzle becomes high, and the solidified slag can be melted and flowed down around the nozzle to be removed. The method of intermittently shutting off the supply of combustion air is, for example, by shutting off one air blowing nozzle in a predetermined nozzle group or shutting off every other nozzle, so that a predetermined amount of combustion air and swirl It is preferable to control so that is obtained.

It is a side view which illustrates the partial cross section in which the air blowing nozzle of this invention was attached to the combustion melting furnace. It is explanatory drawing which illustrates typically the apparatus outline | summary of the combustion melting furnace using the air blowing nozzle of this invention. It is an AA arrow line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion melting furnace 3 Air blowing nozzle 31 Nozzle main body 32 Air introduction pipe 33 Inner intubation 34 Locking means 36 Inner intubation front-end | tip part s Molten slag

Claims (5)

  In a combustion melting furnace for burning and melting combustible components and discharging them as molten slag, an air blowing nozzle arranged so as to cause a swirling flow in the furnace, the air blowing nozzle being disposed around the combustion melting furnace A nozzle main body, an air introduction pipe communicating with the nozzle main body, and an inner intubation pipe that is open at both ends and is movably inserted into the nozzle main body, and one end of the inner intubation pipe is connected to the combustion melting furnace The air blowing nozzle which has the latching means fixed so that it may protrude from the inner wall of the inside of a furnace.   2. The air blowing nozzle according to claim 1, wherein a tip of the inner tube is protruded so as to have a length that does not block the molten slag flowing down the inner wall of the combustion melting furnace.   The air blowing nozzle according to claim 1 or 2, wherein a length of the inner intubation before use is set to 10 to 20 times a length of a tip of the inner intubation protruding from an inner wall of the combustion melting furnace.   The air blowing nozzle according to any one of claims 1 to 3, wherein the nozzle body and / or the inner tube is made of a material selected from the group consisting of stainless steel, carbon steel, alloy steel, and cast iron steel.   It is a combustion melting furnace provided with the air blowing nozzle in any one of Claims 1-4, Comprising: It has a nozzle group which disperse | distributed and arrange | positioned the said several air blowing nozzle to the circumference of a combustion melting furnace A combustion melting furnace having a plurality of nozzle groups at different heights.

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