JP3973919B2 - High temperature gasifier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention swirls a combustible gas containing particles containing incombustible substances and combustible carbonaceous particles in a floating state, which are generated by partially burning (incomplete combustion) combustible waste at a low temperature. The present invention relates to a high-temperature gasification furnace that can be suitably used in a gasification system that performs partial combustion at high temperatures.
[0002]
[Prior art]
Combustible waste, represented by municipal waste, sewage sludge, waste plastic, biomass waste, shredder dust, and waste oil, is very rarely reused and is disposed of in landfills. However, in general, it is reduced in volume and detoxified by incineration and deposited in the final disposal site.
[0003]
Conventionally, a stoker furnace or a fluidized bed furnace has been used for incineration of combustible waste. However, since the stoker furnace and the fluidized bed furnace require a large amount of air to completely incinerate combustible waste, the amount of exhaust gas increases. Moreover, since the metal contained in the flammable waste is also oxidized simultaneously with the incineration treatment of the flammable waste, there is a problem that it is difficult to reuse the metal contained in the flammable waste. Furthermore, for the purpose of reducing the volume of incombustible substances (ash) after incineration of combustible waste, an increasing number of facilities are equipped with melting facilities etc. in the above incineration facilities. As a result, operating costs are increased.
[0004]
Therefore, in recent years, combustible waste is partially combusted (incomplete combustion) at a relatively low temperature using a fluidized bed furnace, and particles containing flammable substances (ash) and combustible carbonaceous particles (char) are produced. A low-temperature gasification furnace that generates flammable gases (eg, hydrogen gas, carbon monoxide gas, hydrocarbon gas, tar) and removes metals contained in flammable waste in an unoxidized state, and flammable -Stage combustion of combustible waste combined with a high-temperature combustion furnace that burns combustible gases and combustible carbonaceous particles and uses the heat of combustion to raise the temperature inside the furnace to slag and reduce the volume of incombustible materials A processing apparatus has been developed (see Japanese Patent Application Laid-Open No. 7-332614).
[0005]
WO98 / 10225 proposes a high-temperature gasification furnace that can be used in a two-stage gasification treatment apparatus for combustible waste. The high-temperature gasifier proposed here has a cylindrical combustion chamber in which a combustible gas containing combustible carbonaceous particles is swirled inside, a throat portion, and a product gas generated in the cylindrical combustion chamber. A non-combustible substance separation chamber (slag separation chamber) that separates slag has a structure in which a cylindrical combustion chamber is disposed above and is integrally coupled in the vertical direction.
[0006]
[Problems to be solved by the invention]
The high-temperature gasification furnace described in the above-mentioned WO98 / 10225 has an advantage that it does not require a wide installation place because it has a vertically long shape.
However, as a result of the study by the present inventor, in the above high-temperature gasification furnace, most of the slag generated in the cylindrical combustion chamber is in a molten state (hereinafter, the molten slag is referred to as molten slag). It has been found that there are the following problems because it flows down the side wall of the gas and the remaining gas swirls with the product gas and reaches the incombustible material separation chamber through the throat portion.
[0007]
(1) The temperature of the cylindrical combustion chamber changes due to fluctuations in the composition and supply amount of particles containing incombustible substances and combustible carbonaceous particles contained in the combustible gas, and the melting point of the generated slag In such a case, a large amount of molten slag may flow into the throat portion from the opening at the bottom of the cylindrical combustion chamber and temporarily close the throat portion.
In particular, when the temperature in the cylindrical combustion chamber suddenly rises, the slag that has been fixed to the side wall of the cylindrical combustion chamber until then becomes molten slag and flows out of the side wall. May flow into and cause blockage.
[0008]
(2) The generated gas continues to swirl even after passing through the throat portion, and due to the centrifugal force, slag (slag mist) swirling with the generated gas is formed on the peripheral wall of the connecting portion between the throat portion and the incombustible substance separation chamber. The slag lump may be fixed and become a large slag lump, and the slag lump may fall into the incombustible material separation chamber and block the slag discharge port of the incombustible material separation chamber.
[0009]
As described above, if the throat part or the slag discharge port is temporarily closed, the internal pressure of the high-temperature gasification furnace is increased, which is a problem from the viewpoint of safety. Further, when the slag discharge port is blocked by the slag lump, there is also a problem that the operation efficiency is lowered because the combustion operation of the combustible gas must be temporarily stopped and the inside of the nonflammable separation chamber must be cleaned.
[0010]
Therefore, an object of the present invention is to provide a high-temperature gasification furnace that can be used advantageously in a two-stage gasification treatment apparatus for combustible waste, which can safely burn a combustible gas continuously for a long period of time. There is to do.
[0011]
[Means for Solving the Problems]
  The present invention is to generate a gas containing hydrogen gas and carbon monoxide gas by partially burning a combustible gas containing particles containing incombustible substances and combustible carbonaceous particles in a suspended state while swirling inside. A cylindrical combustion chamber having a side wall with an inlet for the combustible gas and a conical bottom that descends from the side wall toward an opening formed around the axial position; A high temperature gasification furnace comprising a throat portion extending downward; a nonflammable material separation chamber provided below the throat portion; and a product gas outlet provided in the nonflammable material separation chamber,
  The bottom surface of the cylindrical combustion chamberBut,A flat surface area;Radially extending from the opening toward the side wallThe protrusion shape is maintained even at the tip that contacts the side wall.protrusionAnd consists ofIt is in a high-temperature gasifier characterized by
[0012]
  The protrusion on the bottom surface of the cylindrical combustion chamber isas mentioned above,It is preferable that the front-end | tip extends so that a side wall may be contacted.
[0013]
Preferred embodiments of the high temperature gasification furnace of the present invention are shown below.
1) The protrusion on the bottom surface extends beyond the periphery of the opening so as to protrude inward.
2) The cross section of the protrusion on the bottom surface is triangular, rectangular, semicircular, or a combination thereof.
3) A plurality (usually 3 to 5) of the protrusions are formed on the bottom surface.
4) The plurality of protrusions are formed at equal intervals along the circumference of the bottom surface.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the high-temperature gasification furnace of the present invention will be described with reference to FIGS. 1 and 2 of the accompanying drawings.
FIG. 1 is a cross-sectional view of an example of a high-temperature gasification furnace according to the present invention. FIG. 2 is a view showing the bottom 8 of the cylindrical combustion chamber 1 of the high-temperature gasification furnace shown in FIG. 1, and FIG. 2 (a) shows the cylindrical combustion chamber 1 from above (from the combustible gas inlet 3 side). An example of a cross-sectional view (cross-sectional view taken along line AA in FIG. 1) viewed from below (opening 9 side), FIG. 2B is a schematic cross-sectional view taken along BB in FIG. 2A, and FIG. These are CC partial cross-sectional schematic of FIG. 2 (a).
[0015]
The high-temperature gasification furnace of the present invention is mainly characterized in that projections 10 extending radially from the opening 9 toward the side wall 2 are formed on the surface of the bottom 8 of the cylindrical combustion chamber 1. Here, the cross-sectional shape extending until it contacts the side wall 2 is a triangle, and four protrusions 10 having substantially the same height on the opening 9 side and the side wall 2 side with respect to the bottom surface. An example is shown (see FIG. 2).
[0016]
  The first effect of forming the projection 10 on the bottom 8 of the cylindrical combustion chamber 1 is that the molten slag is projected from the entire periphery of the opening 9 by partially projecting the periphery of the opening 9. There is to be no longer leaked. When a large amount of molten slag is generated, the protrusion 10 on the surface of the bottom 8 is not formed.Flat area(Less than,Flat surface area20), the molten slag is temporarily stored, and the molten slag flows from the opening to the throat portion 11 little by little.
[0017]
  Flat surface areaThe inclination of 20 is usually in the range of 10 to 70 degrees with respect to the horizontal direction, but is preferably in the range of 20 to 60 degrees.Flat surface areaIf the inclination of the angle is less than 10 degrees, the molten slagFlat surface area20 is difficult to flow,Flat surface areaThe molten slag may stick to 20. Also,Flat surface areaIf the inclination of 20 is increased beyond 70 degrees, molten slag willFlat surface area20 becomes too easy to flow, melted slagFlat surface area20 cannot be temporarily stored.
[0018]
The second effect of forming the protrusion 10 on the bottom 8 of the cylindrical combustion chamber 1 is that the generated gas contacts the side surface of the protrusion 10 so that the generated gas directly enters the throat portion 11 while swirling. There is to be no. Usually, the flow of the product gas is faster on the side wall 2 side of the cylindrical combustion chamber 1, so that the protrusion 10 extends until it contacts the side wall 2 of the cylindrical combustion chamber 1 in order to stop the rotation of the product gas. It is preferable.
[0019]
When the cross-sectional shape of the protrusion 10 is a triangle, the angle of the top of the protrusion 10 is preferably in the range of 55 to 110 degrees. When the angle of the top is less than 55 degrees, the top becomes too thin and is easily lost due to contact with the product gas. On the other hand, when the angle of the top portion is larger than 110 degrees, the top portion is difficult to be lost, but the height of the projection portion 10 is lowered and the effect of stopping the swirling of the generated gas of the projection portion 10 is reduced. Moreover, when making the cross-sectional shape of the projection part 10 into a triangle, it is preferable to round the corner | angular part of the projection part 10 at the top.
[0020]
The high temperature gasification furnace of the present invention comprises a cylindrical combustion chamber 1, a throat portion 11, and an incombustible material separation chamber 12 as in the conventional high temperature gasification furnace.
The cylindrical combustion chamber 1 shown in FIG. 1 is supplied with a combustible gas inlet 3 and a gasifying agent (usually a mixed gas of oxygen gas and water vapor) for burning the combustible gas on the side wall 2. A gasifying agent introduction port 4 is provided, and a top gasifying agent introduction port 5 for supplying oxygen or water vapor that tends to be insufficient at the top of the cylindrical combustion chamber 1 is provided at the top of the cylindrical combustion chamber 1. It has been. In FIG. 1, the number of gasifying agent introduction ports 4 is three, but the number of gasifying agent introduction ports 4 is not particularly limited.
[0021]
The combustible gas inlet 3 and the gasifying agent inlet 4 are provided in the side wall 2 so that the combustible gas supplied to the cylindrical combustion chamber 1 descends while turning around the axis of the cylindrical combustion chamber 1. It has been. The combustible gas supplied to the cylindrical combustion chamber 1 forms a swirling flow on the outer peripheral side containing a large amount of particulate combustibles and a swirling flow on the inner peripheral side containing a large amount of gaseous combustibles. A gasifying agent such as oxygen gas is supplied from the gasifying agent introduction port 4 of the side wall 2 toward the swirling flow on the outer peripheral side containing a large amount of particulate combustible matter, thereby promoting gasification of the particulate combustible matter. .
[0022]
In FIG. 1, the opening 9 is provided at the axial position of the cylindrical combustion chamber 1, but the opening 9 is provided at a position slightly decentered from the axial position of the cylindrical combustion chamber 1 (around the axial position). It may be.
[0023]
FIG. 1 shows a high-temperature gasification furnace having a structure in which the periphery of a side wall 2 of a cylindrical combustion chamber 1 is covered with an iron skin 6 and the outer side is covered with a cooling jacket 7 through which a cooling medium passes. Has been. The side wall 2 is formed of a refractory material (usually a castable refractory material), but the surface may be scraped by the erosion action of the molten slag. In this case, erosion of the side wall 2 can be prevented by cooling the temperature of the side wall 2 with the cooling medium to around the melting point of the molten slag and fixing the molten slag (slag self-coating). Although there is no restriction | limiting in particular in a cooling medium, Usually, the water for boilers is used, and some water vapor | steam has generate | occur | produced in the cooling jacket 7. FIG.
[0024]
The bottom portion 8 of the cylindrical combustion chamber 1 is also formed of a refractory material (usually a castable refractory material) in the same manner as the side wall 2, and the cylindrical combustion chamber 1 at the upper part of the high-temperature gasification furnace and the non-combustible material separation chamber 12 at the lower part. The boundary (throat part 11) is formed.
[0025]
The incombustible substance separation chamber 12 is extended so that the lower end of the cylindrical downcomer pipe 14 connected to the throat part 11 is submerged in the cooling water of the water tank part 16, and the generated gas supplied from the throat part 11 And molten slag are blown into the cooling water of the water tank section 16.
Around the cylindrical downcomer 14, a cylindrical riser 15 having an inner diameter larger than the outer diameter of the cylindrical downcomer 14 is installed concentrically with the cylindrical downcomer 14, and is used as cooling water for the water tank section 16. The blown-in product gas passes between the cylindrical downcomer 14 and the cylindrical riser 15 and is discharged from the product gas outlet 17 provided on the side surface of the incombustible substance separation chamber 12. Yes.
[0026]
The cooling water in the water tank section 16 is supplied from the cooling water introduction pipe 13. The cooling water supplied from the cooling water introduction pipe 13 flows down the inner wall surface of the cylindrical downcomer pipe 14 and is stored in the water tank section 16. The cooling water collected in the water tank 16 is taken out from a cooling water outlet 19 provided on the side surface of the water tank.
The molten slag blown into the cooling water of the water tank unit 16 is rapidly cooled by the cooling water of the water tank unit 16 to become slag grains (coarse slag), and is taken out from the slag discharge port 18 provided at the bottom of the water tank unit 16. It is.
[0027]
In FIG. 1, the cylindrical downcomer 14 has a lower inner diameter and a lower tip formed in a serrated shape, but the shape of the cylindrical downcomer 14 is not particularly limited. Further, it is preferable that the cooling water is caused to flow down on the inner wall surface of the cylindrical downcomer pipe 14 while swirling. As a result, the generated gas of the high-temperature gas can effectively come into contact with the cooling water on the inner surface of the cylindrical downcomer 14 and the cooling efficiency of the generated gas can be increased.
[0028]
Here, only an example of the incombustible substance separation chamber 12 is shown, and it is not always necessary to cool the generated gas with cooling water. For example, the heat of the generated gas may be recovered by a radiation boiler and used for power generation.
[0029]
Next, another form of the protrusion 10 formed on the surface of the bottom 8 of the cylindrical combustion chamber 1 will be described with reference to FIGS.
[0030]
1 and 2, the protrusion 10 formed on the bottom 8 of the cylindrical combustion chamber 1 has substantially the same height on the opening 9 side and the side wall 2 side with respect to the bottom surface. However, the height on the side wall 2 side of the protrusion 10 where the flow of the product gas is fast may be increased. 3 to 6 show an example of the bottom 8 of the cylindrical combustion chamber 1 in which the protrusion 10 is formed lower on the opening 9 side with respect to the bottom surface and higher on the side wall 2 side.
[0031]
  In FIG. 3, the width of the bottom surface (the surface in contact with the bottom surface) is the same on the opening 9 side and the side wall 2 side, and the height is low on the opening 9 side and high on the side wall 2 side. The bottom 8 of the cylindrical combustion chamber 1 in which the part 10 is formed is shown. 3 (a) is a cross-sectional view of the cylindrical combustion chamber 1 as viewed from above, and FIG. 3 (b) is a schematic cross-sectional view taken along the line DD in FIG. 3 (a). ) Is an EE partial cross-sectional schematic view of FIG.
  Since the width of the bottom surface of the protrusion 10 is the same on the opening 9 side and the side wall 2 side,Flat surface areaA large area of 20 can be taken. Accordingly, the width of the bottom surface is made the same on the opening 9 side and the side wall 2 side, and the protrusion 10 is low on the opening 9 side and high on the side wall 2 side on the bottom 8 of the cylindrical combustion chamber 1. The formed high-temperature gasification furnace is advantageous when combusting a combustible gas containing a large amount of incombustible substances.
[0032]
FIG. 4 shows the protrusion 10 having the same top angle at the opening 9 side and the side wall 2 side, the height being low at the opening 9 side, and high at the side wall 2 side. ing. 4A is a cross-sectional view of the cylindrical combustion chamber 1 as viewed from above, and FIG. 4B is a schematic cross-sectional view taken along the line F-F in FIG. 4A. ) Is a GG partial cross-sectional schematic diagram of FIG.
Since the angle of the top of the projection 10 is the same on the opening 9 side and the side wall 2 side, the top of the projection 10 on the side wall 2 side is less likely to be damaged and stabilized.
[0033]
  When combusting flammable gas with low incombustibility, that is, for storing molten slagFlat surface areaWhen it is not necessary to make the area of 20 wide, the plurality of protrusions 10 may be connected at the bottom. 5 and 6(All of the embodiments are not included in the present invention)Shows an example of the bottom 8 of the cylindrical combustion chamber 1 in which a plurality of protrusions 10 connected at the bottom are formed.
[0034]
FIG. 5 shows an example in which the protrusion 10 has a triangular cross-sectional shape. Fig.5 (a) is the cross-sectional view which looked at the cylindrical combustion chamber 1 from the upper direction to the downward direction, and FIG.5 (b) is HH partial cross-section schematic of Fig.5 (a).
[0035]
FIG. 6 shows an example in which the cross-sectional shape of the protrusion 10 is a triangle with rounded corners at the top. 6A is a cross-sectional view of the cylindrical combustion chamber 1 as viewed from above, and FIG. 6B is a schematic cross-sectional view taken along the line II of FIG. 6A.
[0036]
  As shown in FIG. 5 and FIG. 6, the width of the bottom surface of the protrusion 10 on the side wall 2 side is widened by connecting a plurality of protrusions 10 at the bottom, so that the top of the protrusion 10 is narrowed. The height on the side wall 2 side can be made higher than the opening 9 side withoutHowever, this embodiment is not included in the present invention..
[0037]
The protrusion 10 illustrated so far extends from the opening 9 to the side wall 2, but extends so that the tip of the protrusion 10 on the opening 9 side protrudes inward beyond the periphery of the opening 9. May be.
FIG. 7 shows an example of the bottom 8 of the cylindrical combustion chamber 1 in which the protrusion 10 extending so that the tip of the protrusion 10 on the opening 9 side protrudes inwardly beyond the periphery of the opening 9 is formed. Show. Fig.7 (a) is the cross-sectional view which looked at the cylindrical combustion chamber 1 from the upper direction to the downward direction, and FIG.7 (b) is the JJ partial cross section schematic of Fig.7 (a).
[0038]
As shown in FIG. 7, by extending the protruding portion 10 so as to protrude inward beyond the periphery of the opening portion 9, it is difficult for the generated gas to enter the throat portion while turning. Therefore, it becomes difficult for the molten slag to adhere to the peripheral wall of the connection portion between the throat portion 9 and the non-combustible substance separation chamber 12.
[0039]
All of the protrusions described so far have a triangular cross-sectional shape, but the shape of the protrusion is not limited to this. FIG. 8 shows an example of a protrusion having a rectangular cross-sectional shape. Fig.8 (a) is the cross-sectional view which looked at the cylindrical combustion chamber 1 from the upper direction to the downward direction, and FIG.8 (b) is the KK partial cross section schematic of Fig.8 (a).
[0040]
  By making the cross-sectional shape of the protrusion 10 rectangular, the width of the protrusion 10 can be reduced compared to the case where the cross-sectional shape is triangular,Flat surface areaThe area of 20 can be widened. Therefore, the high-temperature gasification furnace in which such a protrusion 10 is formed on the bottom 8 of the cylindrical combustion chamber 1 is advantageous when combusting a combustible gas containing a large amount of non-combustible substances.
[0041]
  When combusting a flammable gas containing a large amount of nonflammable substances, that is, when a lot of molten slag is generated,Flat surface areaIt is preferable that the inclination of 20 is set to 50 degrees or more to increase the height of the protrusion 10 on the opening 9 side. FIG. 9 shows an example of the protrusion 10 having a rectangular cross-sectional shape with a height on the opening 9 side with respect to the bottom surface. Fig.9 (a) is the cross-sectional view which looked at the cylindrical combustion chamber 1 from the downward direction from the upper direction, and FIG.9 (b) is LL partial cross-section schematic of Fig.9 (a).
[0042]
  By increasing the height of the protrusion 10 on the opening 9 side,Flat surface areaEven when the slag is fixed to 20, the protruding portion is fixed by the fixed slag.10Therefore, the molten slag can be stably discharged from the opening 9 to the throat portion 11 little by little.
[0043]
  When the width of the protrusion 10 is reduced (when the cross-sectional shape of the protrusion is rectangular),Flat surface areaAlthough the area of 20 becomes wide, the periphery of the opening 9 is wide open, and the amount of molten slag flowing out from the opening 9 to the throat portion 11 may increase substantially. Therefore, when narrowing the width of the protrusion 10, it is preferable to extend the tip of the protrusion 10 on the opening 9 side along the periphery of the opening 9 and partially close the periphery of the opening 9. . In FIGS. 10 and 11, the cylindrical combustion in which the protrusion 10 having a rectangular cross section is formed by providing an extension extending along the periphery of the opening 9 at the tip of the protrusion 10 on the opening 9 side. An example of the bottom 8 of the chamber 1 is shown.
[0044]
FIG. 10 shows an example in which a rectangular molten slag discharge port 22 is formed from the extension 21 of the protrusion 10 and the protrusion 10. FIG. 10A is a cross-sectional view of the cylindrical combustion chamber 1 as viewed from above, and FIG. 10B is a schematic partial perspective view taken along line MM in FIG. 10A.
[0045]
  FIG. 11 shows an example in which an inverted triangular molten slag discharge port 22 is formed from the extension 21 and the protrusion 10 of the protrusion 10. Fig.11 (a) is the cross-sectional view which looked at the cylindrical combustion chamber 1 from upper direction to the downward direction, and FIG.11 (b) is a NN partial cross-section schematic perspective view of Fig.11 (a). By making the molten slag discharge port 22 into an inverted triangle shape as shown in FIG.Flat surface areaWhen the amount of molten slag stored in 20 is large, the amount of molten slag flowing out from the opening 9 to the throat portion 11 can be increased.
[0046]
Another example of the cross-sectional shape of the protrusion 10 is shown in FIG.
FIG. 12A shows a protrusion 10 having a right-angle triangle cross-sectional shape in which the angle of the surface in contact with the product gas is perpendicular to the horizontal direction. By making the angle of the surface on the side in contact with the generated gas perpendicular to the horizontal direction, the resistance of the projection 10 to the generated gas increases, and the effect of stopping the rotation of the generated gas increases.
[0047]
FIG. 12B shows a protrusion 10 having a semicircular cross-sectional shape. The protrusion 10 having a semicircular cross-sectional shape is stable over a long period of time because the top of the protrusion 10 is not easily lost.
[0048]
FIG. 12C shows a protrusion 10 having a cross-sectional shape obtained by cutting the top of FIG. 12A in the horizontal direction.
FIG. 12D shows a protrusion 10 having a trapezoidal cross-sectional shape (a shape obtained by cutting the top of a triangle in the horizontal direction).
The protrusion 10 having a cross-sectional shape obtained by cutting the top in the horizontal direction as shown in FIGS. 12C and 12D is slightly less effective in stopping the swirling of the generated gas, but the top of the protrusion 10 is missing. It is difficult to do and is stable for a long time.
[0049]
The protrusion 10 described so far has a shape extending linearly from the opening 9 toward the side wall 2, but may be a shape extending from the opening 9 toward the side wall 2 in a curved shape. FIG. 13 shows an example of the bottom 8 of the cylindrical combustion chamber 1 in which a protrusion 10 extending in a curved shape from the opening 9 toward the side wall 2 is formed. Fig.13 (a) is the cross-sectional view which looked at the cylindrical combustion chamber 1 from the upper direction downward, FIG.13 (b) is the OO partial cross-sectional schematic of Fig.13 (a).
[0050]
FIG. 13 shows a protruding portion 10 that extends in a curved shape so as to be convex in the traveling direction of the generated gas (arrow S). The effect of stopping the swirling flow of the product gas is enhanced by extending the protrusion 10 in a curved shape so as to be convex in the direction of travel of the product gas.
[0051]
The high-temperature gasification furnace of the present invention is a gasification furnace that generates gas containing hydrogen gas and carbon monoxide gas by supplying oxygen gas and water vapor (steam) as gasification agents to the cylindrical combustion chamber. Can be used. Next, a two-stage gasification treatment apparatus for combustible waste and a method for treating combustible waste using the high-temperature gasification furnace of the present invention will be described.
[0052]
FIG. 14 is a configuration diagram of a two-stage gasification processing apparatus for combustible waste using the high-temperature gasification furnace of the present invention.
In FIG. 14, a fluidized bed gasification furnace 23 is used as a low temperature gasification furnace, and a high temperature gasification furnace 27 in which a protrusion is formed at the bottom of a cylindrical combustion chamber is used as a high temperature gasification furnace according to the present invention. A two-stage gasification processor for combustible waste is shown.
[0053]
Inside the fluidized bed gasification furnace 23, a fluidized medium (eg, sand) fluidized by the fluidized gas b supplied from below the furnace forms a fluidized bed 24. As the fluidizing gas b, oxygen gas, air, water vapor or a mixed gas thereof is usually used. The oxygen gas and air supplied as the fluidizing gas b also act as a gasifying agent for combustible waste.
The combustible waste a supplied to the fluidized bed gasification furnace 23 is placed in the furnace as a fluidizing gas and gasifying agent in the fluidized bed 24 maintained at a temperature of 450 to 850 ° C. (usually 600 ° C.). By the supplied oxygen gas or air, partial combustion (incomplete combustion) is quickly performed and a combustible gas (eg, hydrogen gas, carbon monoxide gas, hydrocarbon gas, tar) is generated. The amount of oxygen gas or air supplied as the fluidizing gas and gasifying agent is preferably 30% or less of the theoretical amount required to completely burn the combustible waste.
[0054]
From the bottom of the fluidized bed gasification furnace 23, the fluid medium is discharged together with the incombustible material through the lock hopper 25, and the coarse incombustible material d is removed by the screen 26. The fluidized medium c from which the incombustible material has been removed is returned to the inside of the fluidized bed gasification furnace 23. Most of the metals (eg, iron, copper, aluminum) contained in the separated coarse incombustible material d are unoxidized because the fluidized bed 24 is at a relatively low temperature and oxygen is insufficient. It is a state.
[0055]
The combustible carbonaceous matter (solid carbon) generated by the partial combustion of the combustible waste is finely pulverized by the stirring motion of the fluidized bed 24 and becomes particles (char) and is accompanied by the flow of combustible gas. A part of the incombustible substance (ash content) is also finely pulverized by the agitating motion of the fluidized bed 24 and becomes particles and is accompanied by the flow of combustible gas.
[0056]
A combustible gas e containing particles containing incombustible substances and combustible carbonaceous particles in a suspended state is supplied from the combustible gas inlet 3 of the high-temperature gasification furnace 27 to the cylindrical combustion chamber 1 while swirling. Descend. The combustible gas and the combustible carbonaceous particles are combusted by the gasifying agent (mixed gas of oxygen gas and water vapor) f supplied from the gasifying agent introduction port 4 and the top gasifying agent introduction port 5. The temperature in the cylindrical combustion chamber 1 is maintained at 1300-1500 ° C. by the combustion heat of the combustible gas and the combustible carbonaceous particles. Carbon monoxide gas and carbon dioxide gas are generated by combustion of combustible carbonaceous particles. Carbon monoxide gas and hydrogen gas are also generated by water gasification reaction of water vapor and combustible carbonaceous particles contained in the gasifying agent.
[0057]
Particles containing incombustible substances contained in the combustible gas e become molten slag in the cylindrical combustion chamber 1. The generated gas (carbon monoxide gas, carbon dioxide gas, hydrogen gas) and molten slag are quenched in the incombustible material separation chamber 12, the generated gas is discharged from the generated gas outlet 17, and the slag particles (coarse slag) are discharged from the slag. 18 is taken out.
[0058]
When the combustible gas e contains a large amount of solids (combustible carbonaceous particles and non-combustible substances), the gas and the solids are separated in advance using a cyclone or the like before being supplied to the high-temperature gasifier 27. The gas is preferably introduced from the combustible gas inlet 4 into the cylindrical combustion chamber 1 of the high-temperature gasification furnace 27 from the top gasifier inlet 5 together with the gasifier f. By introducing the solid separated by the cyclone into the cylindrical combustion chamber 1 of the high-temperature gasification furnace 27 together with the gasifying agent f, the combustible carbonaceous particles in the solid are preferentially in contact with the gasifying agent. The generation of unburned carbon is reduced.
[0059]
The product gas h taken out from the product gas take-out port 17 of the high-temperature gasification furnace 27 is washed by the scrubber 31 to remove a small amount of remaining slag (slag mist) accompanying the product gas.
Carbon monoxide gas and hydrogen gas contained in the product gas h ′ cleaned by the scrubber 31 can be used as various chemical industrial raw materials. It is also possible to incinerate combustible waste with a two-stage gasification apparatus to obtain hydrogen gas, which can be used as a hydrogen source for ammonia synthesis.
The slag collected by the scrubber 31 is settled and concentrated in the storage tank 32 to form fine slag g_fAre discharged to the outside. This fine slag g_fSince it contains a lot of combustible carbonaceous particles, it is preferable to re-supply to the high-temperature gasifier.
[0060]
On the other hand, the slag particles g taken out from the slag discharge port 18 of the high-temperature gasification furnace 27 are appropriately discharged to the storage tank 29 by the lock hopper 28. The coarse slag collected here is separated from water by the screen 30. The coarse slag gc can be used as a material for cement or civil engineering construction.
[0061]
【The invention's effect】
In the high-temperature gasification furnace of the present invention, the molten slag generated in the cylindrical combustion chamber is unlikely to block the throat part, or the slag discharge port is not blocked due to a large slag lump. And can be used stably.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an example of a high-temperature gasification furnace of the present invention.
FIG. 2 is a view showing an example of a bottom portion of a cylindrical combustion chamber of the high temperature gasification furnace of the present invention.
FIG. 3 is a view showing another example of the cylindrical combustion chamber bottom portion of the high-temperature gasification furnace of the present invention.
FIG. 4 is a view showing still another example of the cylindrical combustion chamber bottom of the high-temperature gasification furnace of the present invention.
FIG. 5 shows the present invention.Not included inIt is a figure which shows another example of the cylindrical combustion chamber bottom part of a high temperature gasification furnace.
FIG. 6Not included inIt is a figure which shows another example of the cylindrical combustion chamber bottom part of a high temperature gasification furnace.
FIG. 7 is a view showing still another example of the cylindrical combustion chamber bottom of the high-temperature gasification furnace of the present invention.
FIG. 8 is a view showing still another example of the cylindrical combustion chamber bottom portion of the high-temperature gasification furnace of the present invention.
FIG. 9 is a view showing still another example of the cylindrical combustion chamber bottom portion of the high-temperature gasification furnace of the present invention.
FIG. 10 is a view showing still another example of the cylindrical combustion chamber bottom of the high-temperature gasification furnace of the present invention.
FIG. 11 is a view showing still another example of the cylindrical combustion chamber bottom of the high-temperature gasification furnace of the present invention.
FIG. 12 is a diagram showing an example of a cross-sectional shape of a protrusion formed at the bottom of a cylindrical combustion chamber of a high-temperature gasifier according to the present invention.
FIG. 13 is a view showing still another example of the cylindrical combustion chamber bottom of the high-temperature gasifier according to the present invention.
FIG. 14 is a configuration diagram of an example of a two-stage gasification treatment apparatus for combustible waste using the high-temperature gasification furnace of the present invention.
[Explanation of symbols]
  1 Cylindrical combustion chamber
  2 Side wall
  3 Combustible gas inlet
  4 Gasifying agent inlet
  5 Top gasifying agent inlet
  6 Iron skin
  7 Cooling jacket
  8 Bottom
  9 opening
  10 Protrusion
  11 Throat
  12 Nonflammable substance separation room
  13 Cooling water introduction pipe
  14 Cylindrical downcomer
  15 Cylindrical riser
  16 Water tank
  17 Product gas outlet
  18 Slag outlet
  19 Cooling water outlet
  20Flat surface area
  21 Extension
  22 Molten slag outlet
  23 Fluidized bed gasifier
  24 Fluidized bed
  25 lock hopper
  26 screens
  27 High-temperature gasifier
  28 Lock hopper
  29 Reservoir
  30 screens
  31 Scrubber
  32 Reservoir

Claims (5)

Side wall for generating a gas containing hydrogen gas and carbon monoxide gas by partially burning a combustible gas containing particles containing nonflammable substances and combustible carbonaceous particles in a suspended state while swirling inside. A cylindrical combustion chamber with a combustible gas inlet and a conical bottom that descends from the side wall toward an opening formed around the axial position; from the opening downwards A high temperature gasification furnace comprising a nonflammable material separation chamber provided below the throat portion; and a product gas outlet provided in the nonflammable material separation chamber,
A bottom surface of the cylindrical combustion chamber is composed of a flat surface region, extending radially toward the side wall from the opening, the protrusion that maintains protrusion shape at the distal end in contact with the side wall hot gasifier, characterized by that. The high-temperature gasification furnace according to claim 1, wherein the protrusion on the bottom surface extends so as to protrude inward beyond the periphery of the opening . The high-temperature gasification furnace according to claim 1 or 2, wherein a cross section of the protrusion on the bottom surface is triangular, rectangular, semicircular, or a combination thereof . The high-temperature gasification furnace according to any one of claims 1 to 3, wherein a plurality of the protrusions are formed on a bottom surface . The high temperature gasification furnace according to claim 4 , wherein the plurality of protrusions are formed at equal intervals along the circumference of the bottom surface .

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