JP4078342B2 - Swirl furnace - Google Patents

Description

  The present invention relates to a swirl flow combustion furnace that burns industrial waste such as a flame-retardant material with a swirl flow flame, and in particular, includes a circulation device that sends exhaust gas discharged from the combustion chamber back to the combustion chamber. About things.

Conventionally, as the swirling flow combustion furnace, a combustion chamber, a burner for generating a swirling flow in the combustion chamber, a blower for discharging the burned gas out of the combustion chamber, and an exhaust gas discharged from the combustion chamber A swirl flow combustion furnace provided with a circulation device for returning (combustible gas) to the combustion chamber again, the circulation device comprising an exhaust port provided in the combustion chamber and a wall surface below the height direction of the combustion chamber There is known one having an air pipe that communicates with an introduction port provided in (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2002-22128

  However, this conventional structure requires a burner for generating a swirl flow and a blower for discharging the burned gas out of the combustion chamber, and these burners and blowers are required to have high heat resistance. Therefore, there is a problem that the cost for the equipment becomes high.

  In view of the above problems, the present invention provides a swirling flow combustion furnace that can generate a swirling flow with a simple structure and low cost and can circulate the exhaust gas discharged outside the combustion chamber to the combustion chamber again. It is an issue to provide.

In order to solve the above-mentioned problem, the invention described in claim 1 is a swirl flow combustion furnace that burns an input combustible material with a swirl flow combustion flame, and is discharged from the combustion chamber and the combustion chamber. In a swirl flow combustion furnace provided with a circulation device that sends exhaust gas back to the combustion chamber again, the circulation device includes an exhaust port provided at an upper portion of the combustion chamber and a center in the height direction of the combustion chamber or below the center. The air supply pipe communicates with the inlet provided in the wall of the combustion chamber, and the air supply pipe is connected to the inlet of the combustion chamber in a pipe direction inclined downward from the horizontal , and exhaust gas is supplied to the air supply pipe. A plurality of sub-combustion chambers for combustion are provided in series, and the volume of the sub-combustion chambers is reduced stepwise in the exhaust gas flow direction .

According to the first aspect of the present invention, the exhaust port provided in the upper portion of the combustion chamber and the introduction port provided in the center in the height direction of the combustion chamber or the wall surface below the center are communicated with each other by the air supply pipe. Therefore, the exhaust gas can be circulated with a simple configuration, and no additional equipment such as a blower is required, so the cost does not increase. Further, when the exhaust gas discharged from the discharge port enters the first sub-combustion chamber, the flow velocity thereof is reduced, and the residence time of the exhaust gas in the sub-combustion chamber becomes longer. Then, the exhaust gas further burned during the stay in the auxiliary combustion chamber enters the next auxiliary combustion chamber, and at that time, the flow velocity is accelerated. Thus, since the volume of the sub-combustion chamber is reduced stepwise as it goes in the exhaust gas flow direction, there is an advantage that the gas flow rate does not change abruptly when the exhaust gas passes through.

  In addition, since the air supply pipe is connected to the inlet of the combustion chamber in the direction of the pipe inclined downward from the horizontal, the number of swirling flows generated in the portion below the inlet of the combustion chamber increases. Therefore, the mixing path of the atmosphere and the exhaust gas introduced from the inlet and the combustion path of the mixed gas are lengthened, and the mixed state of the exhaust gas (combustible gas) and the atmosphere is improved. Is significantly increased.

  The invention according to claim 2 is the swirl flow combustion furnace according to claim 1, wherein an air introduction pipe for introducing air from the outside is connected to the middle of the air supply pipe of the circulation device, and the discharge port of the combustion chamber The exhaust gas discharged from the air and the air introduced from the air introduction pipe are mixed and introduced from the introduction port of the combustion chamber.

  According to the second aspect of the present invention, the atmosphere is introduced from the middle of the air supply pipe through which the exhaust gas is sent, and the exhaust gas and the air are mixed in the subsequent air supply pipe portion. As compared with the case where gas is introduced separately, the gas mixing state becomes better and the combustion efficiency is increased.

  Further, in the swirl flow combustion furnace according to claim 1 or 2, the invention according to claim 3 is configured such that an inclination angle of the pipe direction of the air supply pipe downward from the horizontal with respect to the inlet of the combustion chamber is 0. It is characterized by being larger than 15 degrees and 15 degrees or less.

  Here, if the inclination angle of the air supply pipe with respect to the inlet of the combustion chamber downward from the horizontal is 0 degrees or less, that is, upward from the horizontal, the air flow from the inlet to the combustibles accumulated on the bottom surface of the combustion chamber The swirl flow that occurs is not hit, and the combustion of the combusted material is not promoted. Further, if the downward inclination angle of the air pipe is set to 15 degrees or more, the number of turns until the swirling flow hits the combusted material is reduced, so that the mixed state of the exhaust gas and the atmosphere is deteriorated, and the combusted material is not combusted. Not promoted. Further, when the downward inclination angle of the air pipe is 15 degrees or more, the incident angle at which the swirling flow hits the bottom surface of the combustion chamber increases, so that the air current may bounce off the bottom surface, disturbing the swirling flow and destroying it.

  According to the third aspect of the present invention, since the inclination angle of the air pipe toward the combustion chamber inlet from the horizontal is greater than 0 degrees, the combustibles accumulated on the bottom surface of the combustion chamber are A swirl flow generated by the airflow can be applied, and combustion of the combusted object is promoted. Further, since the angle of inclination downward from the horizontal with respect to the inlet of the combustion chamber is 15 degrees or less, the number of swirling times until the swirling flow hits the combusted object increases. Therefore, the mixed state of the exhaust gas and the atmosphere is improved, and the combustion of the combusted material is promoted. In this case, since the incident angle at which the swirling flow hits the bottom surface of the combustion chamber becomes small, there is no possibility that the air current will bounce off the bottom surface and disturb and destroy the swirling flow.

  The invention according to claim 4 is the swirl flow combustion furnace according to any one of claims 1 to 3, wherein the pipe direction of the air supply pipe is in a direction normal to the wall surface of the combustion chamber. It is inclined in the horizontal direction and is characterized in that gas is introduced from the inlet along the inner wall of the combustion chamber.

  According to the fourth aspect of the present invention, the swirl flow can be efficiently generated in the combustion chamber by the flow of the introduced gas without providing a burner or the like for generating the swirl flow.

According to the present invention, the exhaust port provided in the upper part of the combustion chamber and the introduction port provided in the wall surface below the center in the height direction of the combustion chamber or the center are communicated by the air supply pipe. The exhaust gas can be circulated with a simple structure, and no additional equipment such as a blower is required, so the cost does not increase.

  In addition, since the air supply pipe is connected to the inlet of the combustion chamber in the direction of the pipe inclined downward from the horizontal, the number of swirling flows generated in the portion below the inlet of the combustion chamber increases. For this reason, the mixing path of the atmosphere and the exhaust gas introduced from the inlet and the combustion path of the mixed gas become longer, and the combustion efficiency is remarkably increased.

  Referring to FIGS. 1 to 5, reference numeral 1 denotes a swirling flow combustion furnace that burns an input combustible object with a swirling flow combustion flame.

  The swirling flow combustion furnace 1 includes three cylindrical members, that is, an upper member 2, a middle member 3, and a lower member 4. Each of the members 2, 3, 4 has frame bodies 2a, 3a, 4a is provided.

A flange 2a ₁ is provided at the lower end of the frame 2a. Similarly, the flange 3a ₁ is provided at the upper end and the lower end of the frame 3a, and the flange 4a ₁ is provided at the upper end of the frame 4a. Is provided. In a state where the lower member 4, the middle member 3, and the upper member 2 are stacked in this order from the bottom, each of the members 2, 3, 4 is fastened by fastening the flanges 2 a ₁ , 3 a ₁ , 4 a ₁ with bolts 5 and nuts 6. Are integrated to form a swirling flow combustion furnace 1.

  The swirling flow combustion furnace 1 is provided with a combustion chamber 7 formed in a substantially spheroid, and this combustion chamber 7 is provided in each member 2, 3, 4. Combustion chamber upper part 7 a, combustion chamber It is comprised by the middle part 7b and the combustion chamber lower part 7c.

  The combustion chamber 7 is symmetrical with respect to a vertical central axis (hereinafter referred to as a long axis) H (excluding the portion of the inlet T, the outlet 8a, and the inlet 8b), and the long axis H of the combustion chamber 7 The diameter at the horizontal axis L (hereinafter referred to as the short axis) L in the approximate center of the direction is the largest. That is, the position of the short axis L is the maximum diameter portion of the combustion chamber 7. The combustion chamber 7 has a cross-sectional shape that is substantially elliptical or oval so that the ratio (H: L) of the major axis H to the minor axis L is in the range of 7: 4 to 9: 8. More preferably, the shape is such that (H: L) is 5: 4 to 3: 2.

  According to the experiment of the present inventor, when the ratio of the short axis L becomes larger than 9: 8 (H: L), for example, when (H: L) becomes 9: 8.5, it becomes closer to a sphere. Not only can the combustion volume in the combustion chamber 7 be gained, but also the swirling flow of the combustion flame diffuses, making it impossible to increase the combustion path. For this reason, if the combustion efficiency is lowered and a larger amount of air is introduced into the combustion chamber 7 in order to increase the combustion efficiency, the moving speed of the combustion flame is increased more and the combustible gas is discharged from the discharge port 8a before combustion. A malfunction occurred.

  Further, according to the experiment of the present inventor, when (H: L) is less than 7: 4, for example, (H: L) is 8: 4, the top portion in the combustion chamber 7 is too long. The high-temperature normal heat radiation in the above did not work well, the temperature drop at the top of the combustion chamber 7 was likely to become noticeable, and the combustion efficiency was lowered.

  Therefore, as in the embodiment of the present invention, the combustion path length is obtained by making the ratio (H: L) of the major axis H to the minor axis L of the combustion chamber 7 approximately 7: 4 to 9: 8. The effect of both the effect and the heat radiation effect can be obtained in good balance and the combustion efficiency can be increased. In the present embodiment shown in FIG. 1, the combustion chamber 7 has a substantially ellipsoid in which the ratio of the major axis H to the minor axis L (H: L) is 5: 4.

  In addition, the swirl combustion furnace 1 is generated when an input T for supplying a combustible such as a residue obtained by dissolving or decomposing shredder dust generated from a scrapped vehicle from the outside, and the combusted material is burned. A discharge port 8a for discharging gas and an introduction port 8b for introducing the exhaust gas discharged from the discharge port 8a into the combustion chamber 7 are provided.

  The inlet T is inclined obliquely downward so that a combustible material is introduced into a substantially central portion of the combustion chamber 7 in the major axis H direction. The inlet T is installed at a position in the range of about 2/5 to 3/4 of the effective height in the combustion chamber 7 in the long axis H direction of the combustion chamber 7. Also in this case, the input port T is installed toward the central portion of the combustion chamber 7 in the long axis H direction.

  The charging port T is inserted with a charging pipe 10 for charging a combustible from a hopper 9 installed outside the swirling flow combustion furnace 1. The upstream end of the charging pipe 10 and the downstream end of the conveyor pipe 9a that extends horizontally from the side wall of the lower portion of the hopper 9 are connected by a connecting pipe 11 in the vertical direction.

  An upper lid 9 b is provided at the top of the hopper 9, and the upper lid 9 b is opened to put a combustible material into the hopper 9.

  On the upstream side of the input pipe 10, there is provided an extruding bar 12 composed of a bar portion 12 a extending in the pipe direction of the input pipe 10 and an extruding portion 12 b having a shape along the inner peripheral shape of the input pipe 10. The rod portion 12 b of the push rod 12 is inserted into a hole 10 b formed in the center of the side wall 10 a at the upstream end portion of the input tube 10. As a result, by pushing the rod portion 12b toward the downstream side of the charging pipe 10, it is possible to push the combustibles remaining inside the charging pipe 10 into the combustion chamber 7 by the pushing section 12a.

  A screw conveyor 13 is provided in the lower part of the hopper 9 and in the connecting pipe 11 to move the combusted material in the hopper 9 to the downstream side of the connecting pipe 11 and carry it to the charging pipe 10. The power of the motor 14 installed on the upper side of the connecting pipe 11 is driven by the belt 15. In addition, the power of the motor 14 is transmitted to the unlocking mechanism 17 provided in the hopper 9 via the screw conveyor 13 and the belt 16.

  The unraveling mechanism 17 includes a rotating shaft 17a to which a rotational force is applied by the belt 6, and a plurality of unraveling rods 17b attached perpendicularly to the rotating shaft 17a.

The hopper 9 is preferably configured to be tiltable by about θ ₁ = 5 degrees by a predetermined tilting means.

  The discharge port 8a is provided at three locations at equal intervals in the upper portion 7a of the combustion chamber 7, and gas generated by combustion in the combustion chamber is discharged from the discharge port 8a by natural convection. The introduction ports 8b are provided at three equal intervals on the wall surface below the center in the height direction of the combustion chamber middle portion 7b. The exhaust port 8a and the introduction port 8b are communicated with each other by a sub-combustion chamber 18 and an air supply pipe 19 (circulation device), and exhaust gas from the exhaust port 8a passes through the sub-combustion chamber 18 and the air supply pipe 19. Is reintroduced into the inlet 8b.

  An air introduction pipe 20 for introducing air from the outside is connected to the middle of the air supply pipe 19. The downstream side of the portion of the air supply pipe 19 to which the atmosphere introduction pipe 20 is connected constitutes a gas mixing section 19 a that mixes the exhaust gas from the discharge port 8 a and the atmosphere from the atmosphere introduction pipe 20.

The gas mixing section 19a of the air supply pipe 19 is connected to the inlet 8b of the combustion chamber 7 in a pipe direction inclined by θ ₂ = 5 degrees downward from the horizontal. As a result, exhaust gas or the like is easily blown into the combusted material that is introduced into the combustion chamber 7 and located in the combustion chamber lower portion 7c. Furthermore, since the number of swirling of the swirling flow generated in the portion below the inlet 8b increases, the mixing path of the atmosphere and the exhaust gas and the combustion path of those mixed gases become longer, and the combustion efficiency is remarkably increased.

Also, feed gas mixing portion 19a of the trachea 19, the horizontal direction 15 degrees to tangent line direction b in the normal direction a with respect to the horizontal direction .theta.3 = 75 degree inclined surface (wall surface of the combustion chamber 7 of the wall surface of the combustion chamber 7 Tilted) and connected. As a result, a mixed gas of exhaust gas and the atmosphere is introduced from the inlet 8b along the inner wall of the combustion chamber 7, and the swirl flow efficiently into the combustion chamber 7 by the introduced mixed gas. Can be generated.

Atmospheric pressurizing means (not shown) such as a blower is connected to the end of the atmospheric introduction pipe 20. By the air pressure means, the air introducing pressure into the combustion chamber 7 is 0.5～0.7MPa, the air introduction amount ^is 600Nmm ³ / h~700Nmm 3 / h.

  The sub-combustion chamber section 18 includes three sub-combustion chambers 18a, 18b, and 18c, which are a first sub-combustion chamber 18a, a second sub-combustion chamber 18b, and a third sub-combustion chamber 18c. Each of the sub-combustion chambers 18a, 18b, and 18c has a substantially spherical shape, and the radius of the spherical body of the first sub-combustion chamber 18a is larger than the diameter of the discharge port 8a. Further, the radius of the spherical body becomes smaller in the order of the first sub-combustion chamber 18a, the second sub-combustion chamber 18b, and the third sub-combustion chamber 18c.

  Thereby, when the exhaust gas discharged from the discharge port 8a enters the first sub-combustion chamber 18a, the flow velocity thereof is decelerated, and the residence time of the exhaust gas in the first sub-combustion chamber 18a becomes longer. Then, the exhaust gas further burned during the stay in the first sub-combustion chamber 18a enters the second sub-combustion chamber 18b and the third sub-combustion chamber 18c in this order, and the flow velocity is accelerated at that time. As described above, since the radius of the spherical body gradually decreases in the order of the first sub-combustion chamber 18a, the second sub-combustion chamber 18b, and the third sub-combustion chamber 18c, the flow velocity of the gas is increased when the exhaust gas passes through. It does not change rapidly.

  A discharge pipe 21 extending downward is connected in the middle of the air supply pipe 19, and a circulation part 23 is connected to the lower end of the discharge pipe 21 via a connection part 22. The connection portion 22 and the circulation portion 23 are formed on the side of the combustion chamber lower portion 7c over the entire circumference. The circulation portion 23 is connected to an external exhaust pipe 24 that communicates with the outside. An atmospheric suction means (not shown) is connected to the.

  The atmospheric suction amount by the atmospheric suction unit is set to be larger than the atmospheric introduction amount by the atmospheric pressurization unit, so that the combustion chamber 7 has a negative pressure of about −1 mmAq to −5 mmAq. Yes. The pressure in the combustion chamber 7 of -1 mmAq to -5 mmAq prevents the combustion flame from flowing back from the inlet T, and the discharge speed of the combustible gas generated from the combusted material and the combustion flame to the outlet 8a becomes too fast. There is no pressure.

  An ash discharge passage 25 communicates with the bottom of the bottom of the combustion chamber lower portion 7c, and a shaker 26 that can be vibrated from the outside is installed. The shaker 26 has two upper and lower meshes, with the upper mesh being coarse and the lower mesh being fine. By vibrating the shaker 26 from the outside, the fine ash after combustion falls into the ash discharge passage 25, and the ash is discharged to the outside by a predetermined discharge means.

  Next, the operation of this embodiment will be described.

  First, an object to be burned is put into the hopper 9. When the motor 14 is driven, the combustion object in the hopper 9 is decomposed by the unraveling mechanism 17, and the combustion object that has been decomposed and dropped to the lower part of the hopper 9 is moved downstream of the conveyor tube 9 a by the screw conveyor 13. Carried. The combusted material conveyed to the downstream side of the conveyor pipe 9a falls through the connecting pipe 11 to the input pipe 10 and is input into the combustion chamber 7 from the input port T due to the inclination of the input pipe 10. This combustible material is dissolved or decomposed after dissolving or decomposing the shredder dust, which is a part of the scrapped automobile, containing a large amount of resin, such as instrumental panels and seats, with solvent or steam. This is a residue obtained by drying the remaining sludge-like substance and removing the liquid component. This residue is in a solid / powder form and contains metal, earth and sand, glass and carbon in addition to the undecomposed resin.

  Next, by injecting a seed flame (such as a newspaper with fire) from the inlet T, ignition is performed on the combusted material in the combustion chamber 7. Then, the atmosphere pressurizing means is driven to supply the atmosphere from the atmosphere introduction pipe 20 to the introduction port 8b. As a result, air is introduced from the three inlets 8 b along the inner wall of the combustion chamber 7, and a spiral swirl flow is generated in the combustion chamber 7. And the combustion flame of a to-be-combusted material swirls on a swirl flow.

  The gas generated by burning the combustible in this swirling flow is discharged from the discharge port 8 a and enters the auxiliary combustion chamber 18. The gas that has entered the first sub-combustion chamber 18a of the sub-combustion chamber 18 is slowed in flow rate as described above, so that the residence time in the first sub-combustion chamber 18a becomes longer, and the unburned gas contained in the exhaust gas. And soot is reburned. Furthermore, re-combustion of unburned gas and soot is performed while accelerating the flow velocity in the second sub-combustion chamber 18b and the third sub-combustion chamber 18c. Then, the reburned exhaust gas flows from the third sub-combustion chamber 18c into the air supply pipe 19, and is mixed with the air introduced from the air introduction pipe 20 in the gas mixing section 19a. This mixed gas is introduced into the combustion chamber 7 from the inlet 8b.

  Further, the exhaust gas from the air supply pipe 19 and a part of the atmosphere from the air introduction pipe 20 flow into the discharge pipe 21, and the exhaust gas circulates through the circulation section 23 via the connection section 22. The lower member 4 is kept warm by the heat of the exhaust gas that circulates in the circulation section 23, and a temperature drop in the combustion chamber 7 is prevented. In the initial stage of combustion, the temperature in the combustion chamber 7 rises quickly.

The exhaust gas exhausted from the external exhaust pipe 24 after circulating through the circulation part 23 in this manner is sent to a secondary combustor (not shown) together with the combustion flame via the catalyst. In this secondary combustor, unburned gas (hc, carbon monoxide, etc.) that cannot be combusted in the auxiliary combustion chamber 18 is burned at 800 to 900 degrees Celsius, and these are converted into CO ₂ and H ₂ O. . The exhaust gas that has passed through the secondary combustor is processed into CO ₂ and H ₂ O in an exhaust gas processing system.

  In this state, when a predetermined amount of the combusted material is intermittently input from the input port T, the input combusted material is discharged near the center in the height direction of the combustion chamber 7 and reacts with the swirling flow in the combustion chamber 7. Burned. At this time, the inside of the combustion chamber 7 is heated to a high temperature (from 1200 to 1350 degrees Celsius) by a swirling combustion flame.

As a result of the combustion treatment of the residue in the swirling flow combustion furnace 1 configured as described above, the combustion state was good, and a furnace temperature of 1350 degrees Celsius could be obtained in the central portion of the combustion chamber 7 having the highest temperature. Further, the generation rate of soot was suppressed to 1% or less, the CO concentration was suppressed to 10 ppm or less, and the dioxin concentration was suppressed to 0.4 ng / m ³ or less.

  In this embodiment, the gas mixing section 19a of the air supply pipe 19 is connected to the inlet 8b of the combustion chamber 7 in a pipe direction inclined by 5 degrees downward from the horizontal, but the present invention is limited to this. However, the number of swirling swirls generated in the portion below the inlet 8b in the combustion chamber 7 is increased, and the mixing path of the atmosphere and the exhaust gas and the combustion path of these mixed gases are lengthened. Any inclination angle that significantly increases the combustion efficiency may be used. Specifically, the inclination angle is adjusted to be greater than 0 degree and 15 degrees or less according to the pressure of the atmosphere to be introduced and the introduction amount.

Further, in the present embodiment, the gas mixing portion 19a, is (horizontally 15 degrees inclined with respect to the tangential direction of the wall surface of the combustion chamber 7) horizontally 75 degrees inclined with respect to the normal direction of the wall surface of the combustion chamber 7 However, the present invention is not limited to this, and the mixed gas is introduced from the introduction port 8b along the inner wall of the combustion chamber 7 so that the swirl flow is efficiently generated in the combustion chamber 7. I need it. Specifically, it is inclined in the horizontal direction with respect to the normal direction of the wall surface of the combustion chamber according to the pressure and introduction amount of the atmosphere to be introduced, the size and shape of the combustion chamber, and the like.

  In the present embodiment, the introduction ports 8b are provided at three equal intervals on the wall surface below the center in the height direction of the combustion chamber middle portion 7b. However, the present invention is not limited to this. For example, the introduction ports 8b may be provided in two places where the height positions of the combustion chamber 7 are different, and the introduction port 8b to be used may be changed depending on the amount of the combusted material introduced into the combustion chamber 7.

  In addition, although this embodiment demonstrated the substantially elliptical combustion chamber 7, this invention is not limited to this. For example, a combustion chamber 7 as shown in FIG. 6 may be used.

  The combustion chamber 7 has a slightly flattened inner wall surface of the combustion chamber upper portion 7a so as to swell outward from the substantially elliptical shape, and is near the central portion of the combustion chamber 7 in the long axis H direction (the maximum diameter of the combustion chamber 7). (Near) is a plane substantially inscribed in a substantially elliptical shape, and the combustion chamber lower portion 7c is also a plane substantially inscribed in a substantially elliptical shape parallel to the short axis L.

  In addition, a plane that is substantially inscribed in an approximately elliptical shape is also formed between the vicinity of the center in the long axis H direction in the combustion chamber 7 (near the maximum diameter of the combustion chamber 7) and the inner wall surface of the combustion chamber lower portion 7c. Other configurations are the same as those of the embodiment shown in FIG.

  In the present embodiment, the inner wall surface of the upper portion 7a of the combustion chamber 7 has a slightly flat curved surface, so that the radiant heat from the swirling flow combustion flame, which is a heat source, is effectively reflected by the inner wall surface of the upper chamber 7a. The effect can be further enhanced to further improve the combustion efficiency.

  Furthermore, by making the vicinity of the center (near the maximum diameter of the combustion chamber 7) a flat surface and the inner wall surface of the lower portion 7c also a flat surface, the contact area of the combustible gas can be increased compared to the curved surface. The combustion efficiency can be further improved by increasing the generation rate of the combustible gas.

  Also in the present embodiment, the combustion chamber 7 is formed in a cross-sectional shape such that the ratio (H: L) of the major axis H to the minor axis L is in the range of 7: 4 to 9: 8. More preferably, the shape is such that (H: L) is 5: 4 to 3: 2.

Sectional drawing which shows the swirl flow combustion furnace which concerns on embodiment of this invention II-II sectional view of FIG. III-III sectional view of FIG. IV-IV sectional view of FIG. 1 is a cross-sectional view taken along line VV in FIG. Sectional drawing which shows the swirl flow combustion furnace which concerns on other embodiment of this invention.

Explanation of symbols

7 Combustion chamber 8a Discharge port 8b Inlet port 20 Atmospheric introduction pipe

Claims (5)

A swirl flow combustion furnace for combusting an input combustible with a swirl flow flame, comprising a combustion chamber and a recirculation device for returning exhaust gas discharged from the combustion chamber to the combustion chamber again. In a flow combustion furnace,
The circulation device has an air supply pipe that communicates an exhaust port provided in the upper part of the combustion chamber and an introduction port provided in a wall surface below the center in the height direction or the center of the combustion chamber,
The air supply pipe is connected to the inlet of the combustion chamber in a pipe direction inclined downward from the horizontal ,
A plurality of sub-combustion chambers for combusting the exhaust gas are provided in series in the air supply pipe, and the volume of the sub-combustion chamber is reduced stepwise in the direction of the exhaust gas flow. Furnace. An air introduction pipe that introduces air from the outside is connected in the middle of the air supply pipe of the circulation device, and the exhaust gas discharged from the exhaust port of the combustion chamber is mixed with the air introduced from the air introduction pipe. The swirl flow combustion furnace according to claim 1, wherein the swirl flow furnace is introduced from an introduction port. 3. The swirl flow combustion according to claim 1, wherein an inclination angle of the pipe direction of the air supply pipe, which is lower than the horizontal with respect to the inlet of the combustion chamber, is greater than 0 degree and equal to or less than 15 degrees. Furnace. The pipe direction of the air supply pipe is inclined in the horizontal direction with respect to the normal direction of the wall surface of the combustion chamber, and gas is introduced from the inlet along the inner wall of the combustion chamber. The swirl flow combustion furnace according to any one of claims 1 to 3. The swirl flow combustion furnace according to any one of claims 1 to 4, wherein the sub-combustion chamber has a substantially spherical shape.

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