CN212504738U - Gasification furnace for carbon-containing waste - Google Patents

Abstract

The utility model provides a carbonaceous waste gasifier, which can conveniently integrate combustible waste gas and combustible carbonaceous waste in a gasifier to gasify to generate synthesis gas. The gasification furnace comprises a gasification chamber and a chilling chamber, wherein a slag discharging port is arranged at the bottom of the gasification chamber, a down pipe is arranged right below the slag discharging port, a burner is arranged at the top of the gasification chamber, and the burner comprises a central annular channel, a first annular channel, a second annular channel and a third annular channel, wherein the central annular channel is sleeved from inside to outside and used for inputting combustible waste gas, the first annular channel is used for inputting an oxidant, the second annular channel is used for inputting combustible carbon-containing waste, and the third annular channel is used for inputting the oxidant; a combustion space for the reaction of the combustible waste gas and the oxidant is reserved between the outlet at the bottom of the central annular channel and the outlet at the bottom of the first annular channel; a purging device is arranged between the slag discharging port and the descending pipe, and a purging port is arranged on the purging device.

Description

Gasification furnace for carbon-containing waste

Technical Field

The utility model relates to a technology for processing and utilizing carbon-containing wastes, in particular to a gasification furnace for carbon-containing wastes and a gasification method for carbon-containing wastes.

Background

The solid carbon-containing wastes such as sludge, livestock and poultry wastes and other biomass resources have larger reserves, wider distribution and reproducibility, lower contents of S, N and ash, and much smaller discharge amount of sulfur, nitrogen oxide and dust after combustion than fossil fuels, and are more environment-friendly. But because the carbonaceous waste has low quality and energy density and high moisture content, the carbonaceous waste is difficult to store and transport. If the fuel is directly used as fuel, the combustion heat efficiency is low and the environment is seriously polluted. At present, the industry proposes to use pyrolysis or gasification process to convert the carbon-containing waste into liquid or gas raw material with larger energy density. At present, the mainstream biomass gasification process in the world needs pretreatment, one is to compact the biomass into particles with high quality and energy density under high pressure, and the other is hydrothermal treatment to remove redundant moisture. The complex pretreatment process also consumes more energy, generates unnecessary waste and has higher cost.

If the gas combustible waste such as redundant coke oven gas, hydrogen and the like generated by most chemical plants at present cannot be further utilized, the waste gas is directly burnt and discharged by a waste gas torch, and the energy waste is serious.

SUMMERY OF THE UTILITY MODEL

The utility model provides a carbonaceous waste gasifier, which can be used for conveniently and energy-saving the integration of combustible waste gas and combustible carbonaceous waste in a gasifier to gasify and generate synthesis gas.

The utility model discloses a reach its purpose, provide following technical scheme:

the utility model provides a gasification furnace for carbon-containing wastes, which comprises a gasification chamber and a chilling chamber arranged below the gasification chamber, wherein the bottom of the gasification chamber is provided with a slag discharge hole, a down pipe vertically extending into the inner cavity of the chilling chamber is arranged right below the slag discharge hole, the top of the gasification chamber is provided with a burner,

the burner comprises a central annular channel for inputting combustible waste gas, a first annular channel for inputting an oxidant, a second annular channel for inputting combustible carbon-containing waste and a third annular channel for inputting the oxidant, which are sequentially sleeved from inside to outside, wherein the top of each channel is provided with an inlet, and the bottom of each channel is provided with an outlet;

a combustion space for the reaction of combustible waste gas and an oxidant is reserved between the outlet at the bottom of the central annular channel and the outlet at the bottom of the first annular channel;

the slag discharging device is characterized in that a purging device is installed between the slag discharging port and the descending pipe, purging ports used for spraying water vapor or carbon dioxide to slag falling through the slag discharging port are formed in the purging device, the purging ports are multiple, and the purging ports are distributed at equal intervals.

In some embodiments, the wall thickness of the central annular channel is reduced at its bottom outlet and the wall thickness of the outlet end face of the central annular channel is from 0.4mm to 0.6 mm.

In some embodiments, the purge port is configured such that the injection direction of the steam or the carbon dioxide is obliquely downward and the angle between the injection direction and the central axis of the gasification furnace is 30 to 45 degrees.

In some embodiments, the purge device comprises an annular purge conduit and a gas supply conduit connected to the annular purge conduit, the gas supply conduit being connected to a source of water vapor or a source of carbon dioxide gas;

the annular purging pipeline is provided with a plurality of purging ports.

In some embodiments, the annular purge conduit is a circular coil with purge ports on the same circumference equally spaced.

In some embodiments, the outlet direction of the bottom of the first annular channel is a vertical direction; and the outlet directions of the bottoms of the second annular channel and the third annular channel are both inclined downwards towards the central axis of the burner and form an included angle of 50-60 degrees with the central axis of the burner.

In some embodiments, the combustible carbonaceous waste conveyed by the second annular channel is solid combustible carbonaceous waste or is a combustible carbonaceous waste slurry.

The utility model provides a technical scheme has following beneficial effect:

1. the utility model provides a gasification furnace, burner structure wherein adopts unique four-channel design, and central annular passage is combustible waste gas passageway, and in gasification, the oxidant among combustible waste gas and the first annular passage reacts the burning production a large amount of heats in the combustion space between two passageways, and the carbonaceous wastes material in excessive oxidant that first annular passage let in and the adjacent second annular passage can be heated to these heat energies reaches the effect of self-heating to can save the external energy input.

2. The carbonaceous waste, particularly the solid carbonaceous waste, usually contains part of ash which cannot be gasified, the ash is melted into liquid slag after being gasified at high temperature in the gasification chamber, and the slag also contains a small amount of unreacted carbon; the utility model discloses an installation sweeps the device between lower slag notch and downcomer, sweeps the device and is equipped with the mouthful that sweeps of a plurality of even interval distribution to can be to the slag that falls via lower slag notch does not have 360 jetting vapor or carbon dioxide at dead angle, can promote the reaction of carbon in the slag, do benefit to and reduce the carbon residue volume, in the reaction back slag gets into the chilling chamber, improve gasification efficiency and energy utilization.

3. The utility model discloses a gasifier adopts the design of four passageway nozzles and under the cinder notch with install between the downtake and sweep the device, in the operation, combustible waste gas that lets in by central annular channel and the oxidant contact reaction that lets in by first annular channel, combustible waste gas fully burns in the combustion space between the two, the heat of releasing simultaneously in the combustion process can heat the excessive oxidant that lets in by first annular channel to provide excessive high temperature oxidant, the high temperature oxidant that produces can light the combustible carbonaceous waste (for example liquid thick liquids) that lets in by second annular channel more easily, promote the gasification of this combustible carbonaceous waste; while the outermost third annular channel further promotes the reaction, in particular for slurry atomization. The reacted slag flows downwards from the gasification chamber to the vicinity of the slag discharging port, is blown by a blowing device and then further reacts, finally enters the chilling chamber through the downcomer, and the synthesis gas generated by the reaction enters downstream equipment after being washed and purified by the chilling chamber. Through the utility model discloses a gasifier can integrate industry combustible waste gas and combustible carbonaceous waste (for example solid carbonaceous discarded object or the thick liquids of making by it) in a gasifier, can utilize combustible waste gas to provide high energy, promotes the gasification of solid carbonaceous discarded object to produce the synthetic gas, this synthetic gas can be used for low reaches chemical products synthesis etc..

Drawings

FIG. 1 is a schematic view of a gasification furnace;

FIG. 2 is a schematic view of a burner structure;

FIG. 3 is a schematic view of the structure of the central annular channel;

FIG. 4 is a schematic view of the installation location of the purge device;

fig. 5 is a schematic structural diagram of the annular purging pipeline of the purging device in a top view.

Detailed Description

In order to better understand the technical solution of the present invention, the contents of the present invention are further described below with reference to the following embodiments, but the contents of the present invention are not limited to the following embodiments.

The terms of orientation of up, down, left, right, front, back, top, bottom, and the like referred to or may be referred to in this specification are defined relative to the configuration shown in the drawings, and are relative terms, and thus may be changed correspondingly according to the position and the use state of the device.

Referring to fig. 1-5, the utility model provides a carbonaceous waste gasifier, it is the same with the gasifier of the conventional in this field including gasification chamber 2, chilling chamber 3, downcomer 6 and lower slag notch 5, chilling chamber 3 is located gasification chamber 2 below, opens the slag notch 5 of setting down in gasification chamber 2's bottom, is equipped with downcomer 6 under lower slag notch 5, and downcomer 6 is vertical to stretch into 3 inner chambers of chilling chamber, installs nozzle 1 at gasification chamber 2 top. The same or similar parts with the conventional gasification furnace are not described in detail, and those skilled in the art can understand or know the conventional technology or common general knowledge in the technical field of gasification furnace. The following description will focus on the details of the improvements of the gasification furnace developed for the gasification of carbonaceous waste of the present invention.

The utility model provides a gasification furnace, its nozzle 1 is the design of four passageways. Referring to fig. 2, in particular, the burner 1 comprises a central annular channel 8 for feeding waste flammable gas, a first annular channel 9 for feeding an oxidizing agent, a second annular channel 10 for feeding waste flammable carbon-containing matter and a third annular channel 11 for feeding an oxidizing agent. Of the four channels, the first annular channel 9 is located at the periphery of the central annular channel 8, the second annular channel 10 is located at the periphery of the first annular channel 9, and the third annular channel 11 is located at the periphery of the second annular channel 10, so as to form a four-channel structure sleeved from inside to outside in sequence. The four channels are all vertically arranged, the top of each channel is an inlet, and the bottom of each channel is an outlet. Wherein, a space 17 is left between the outlet at the bottom of the central annular channel 8 and the outlet at the bottom of the first annular channel 9, and the space is used as a space for the contact reaction of the combustible waste gas output by the central annular channel 8 and the oxidant in the first annular channel 9, namely as a combustion space or an autothermal chamber. Specifically, the length of the central annular passage 8 is shorter than the length of the first annular passage 9, and the waste flammable gas output from the central annular passage 8 firstly enters the first annular passage 9 to react with the oxidant therein. In the operation process of the gasification furnace, by means of the structural design, the combustible waste gas reacts with the oxidant in the first annular channel 9, and the combustion generates a large amount of heat, so that the excessive oxidant in the first annular channel 9 can be heated, the high-temperature excessive oxidant is provided, and the self-heating effect is achieved; meanwhile, the device can also play a role in heating combustible carbon-containing waste in the adjacent second annular channel 10, so that the input of external heat can be reduced; and because of the high temperature excess oxidant that can be generated, the combustible carbonaceous waste, particularly slurry, in the second annular channel 10 is made more susceptible to ignition and gasification. Further, a third annular channel 11 is arranged on the outermost side of the burner 1, and the oxidant output through the channel can promote the gasification reaction of the combustible waste on one hand, and on the other hand, the combustible waste slurry can be atomized, so that the gasification of the slurry-shaped combustible waste is promoted better.

Referring to fig. 1 and fig. 4-5, a purging device 4 is further installed between the slag hole 5 and the downcomer 6, a plurality of purging holes 16 are formed in the purging device 4, and the purging holes 16 are uniformly distributed at intervals. The function of the purging device 4 is to inject water vapor or carbon dioxide into the slag falling through the slag tap 5, so that the slag can be fully reacted further before entering the chilling chamber 3 through the downcomer 6, and the amount of carbon residue is reduced. And the blowing ports 16 are uniformly distributed at intervals, so that liquid slag falls through the slag discharging port 5 and finally enters the chilling chamber 3, and can be blown by 360-degree annular space, further reaction of carbon residue in the slag is realized, and the carbon residue is reduced to a greater extent.

Referring to fig. 2, further, the wall thickness of the bottom outlet of the central annular channel 8 is designed to be thinner than that of the rest of the central annular channel 8, so that the wall thickness of the end face of the bottom outlet of the central annular channel 8 is 0.4-0.6mm, for example 0.5mm, and by adopting the structural design, a fire-extinguishing flame (as shown in fig. 1) can be formed by the reaction between the waste flammable gas of the central annular channel 8 and the oxidant of the first annular channel 9, thereby reducing the influence of high temperature on the burner 1 and prolonging the service life of the burner.

Further, as shown in fig. 2, the outlet at the bottom of the first annular channel 9 is designed to have an outlet direction (i.e. a discharging direction) as a vertical direction, i.e. the outlet direction has no angle, during the operation, the oxidant gas velocity of the first annular channel 9 can be specifically controlled to be, for example, 100-; the high temperature oxidant will be output vertically downwards from the first annular channel 9. The outlet directions (i.e. the discharging directions) of the bottoms of the second annular channel 10 and the third annular channel 11 are both designed to be inclined downwards towards the central axis of the burner 1, and the outlet directions and the central axis (shown by the dotted line in fig. 2) of the burner 1 form an included angle of 50-60 degrees, during the operation, the material speed of the second annular channel 10 can be specifically controlled to be, for example, about 1-2m/s, and the oxidant gas speed of the third annular channel 11 can be controlled to be, for example, about 100-150 m/s. By designing the outlet directions of the channels in such a way, combustible carbonaceous waste, particularly slurry, output by the second annular channel 10 can be fully contacted with high-temperature excess oxidant output by the first annular channel 9 vertically downwards, so that the material heating and gasification reaction are facilitated; meanwhile, the oxidant output by the third annular channel 11 can be in more sufficient contact with the combustible carbon-containing waste, especially the slurry output by the second annular channel 10 to promote the reaction, especially the atomization of the slurry.

More specifically, referring to fig. 1 and 4-5, the opening direction (i.e., the gas outlet direction, and the oblique dotted line in fig. 4 is an illustration of the direction) of the purge device 4 installed between the slag tap 5 and the downcomer 6 is set such that the steam or carbon dioxide is injected in an oblique downward direction, and the angle 13 between the injection direction and the central axis (as indicated by the vertical dotted line in fig. 4) of the gasifier is 30-45 degrees. By adopting the design of the purging opening, the slag splashing can be prevented, and the slag discharging opening 5 can be prevented from being blocked. In a specific application, the purge gas velocity may be controlled to be 0.2-0.5 m/s.

Further, the purging device 4 specifically comprises an annular purging line 15 and a gas supply line 7, wherein the gas supply line 7 and the annular purging line 15 are connected for supplying a purging gas, i.e. carbon dioxide or water vapor; in particular, the gas supply line 7 is connected (not shown) to a source of water vapor or carbon dioxide, such as a corresponding gas storage tank, or other process line or device capable of supplying water vapor or carbon dioxide. A plurality of purge ports 16 are opened in the annular purge conduit 15, specifically, inside the annular purge conduit 15, so that the corresponding purge gas can be injected to the slag falling through the slag tap 5. In some embodiments, the annular purge line 15 may be a circular coil, and the purge ports 16 formed in the annular purge line are equidistantly spaced apart from one another on the same circumference, so as to achieve a purge effect of 360 °. The specific fixing manner of the purging device 4 is not particularly limited as long as the fixing purpose can be achieved; for example, a fixing ring 14 can be arranged around the annular purging pipeline, the fixing ring 14 is tightly connected with the annular purging pipeline 15, and the fixing ring 14 is fixedly connected with the bottom of the slag tap 5, so that the position of the purging device 4 between the slag tap 5 and the downcomer 6 is fixed, which is only an example of a fixing manner here, and other conventional fixing manners are not excluded. Preferably, the purge port 16 may be designed as an elongated purge port, thereby further facilitating the injection of the purge gas.

The utility model provides a carbonaceous discarded object gasifier specially adapted carbonaceous discarded object's gasification. The carbonaceous waste that can be used for gasification includes, for example, solid combustible carbonaceous waste, and may further include liquid carbonaceous waste, and may also include gaseous combustible carbonaceous waste.

Wherein, the solid combustible carbonaceous waste such as but not limited to sludge, livestock and poultry waste, straw, wood chips, kitchen waste and other combustible carbonaceous solid wastes, preferably the carbon content of the solid combustible carbonaceous waste is more than 60 wt%. The liquid carbon-containing waste is, for example, a chemical waste liquid containing organic substances, such as phenol-containing waste water and black water, which are difficult to treat in chemical industry. The gaseous combustible carbonaceous waste is, for example, excess coke oven gas generated in chemical plants.

Utilize the utility model provides an in the gasification technology of gasifier carbonaceous discarded object, in gasification, combustible waste gas carries through the central annular channel 8 of nozzle 1, and combustible waste gas can be gaseous combustible carbonaceous waste or be the combustible waste gas that does not contain carbon, and gaseous combustible carbonaceous waste wherein is as described in the foregoing, no longer gives unnecessary details; the carbon-free combustible waste gas is surplus hydrogen generated by a chemical plant. During the gasification process, excess oxidant is fed into the first annular channel 9 of the burner 1. During the gasification process, combustible carbon-containing waste is conveyed through the second annular channel 10 of the burner 1, and the combustible carbon-containing waste can be solid combustible carbon-containing waste or slurry prepared from the solid combustible carbon-containing waste and liquid carbon-containing waste; preferably, the slurry prepared from the solid combustible carbon-containing waste and the liquid carbon-containing waste is convenient to convey. During gasification, an oxidant is fed into the third annular channel 11. Among these, the slurry introduced into the second annular channel 10 can be prepared by the following steps:

the solid combustible carbonaceous waste is dried, for example, at a low temperature, for example, at 100 ℃ or lower, until the external water content is 0. Drying and pulverizing to obtain solid particles with average particle size of 65-90 μm (such as 75 μm), and mixing the solid particles with liquid carbonaceous waste to obtain slurry with solid particles volume percentage of 50-60%. In the prior art, the concentration of gasified slurry such as coal water slurry and the like is usually required to be higher than 60 percent to ensure that a gasification furnace can stably and smoothly operate, which is caused by the fact that a large amount of moisture takes away heat in the gasification process; and the utility model discloses in, be used for letting in waste flammable gas's central annular channel 8 through the setting, provide energy through the combustible gas in this passageway, can reduce moisture and take away the heat and the influence that brings, consequently, can accomplish to reduce the granule solubility of thick liquids to the level below 60%.

In the gasification process, ignition and ignition are carried out by using an ignition device such as an oil gun as is conventional in the art; the combustible waste gas in the central annular channel 8 is ignited and reacts with the oxidant, so that the combustible waste gas can be used for providing energy, the combustible waste gas and the oxidant react in the combustion space in the first annular channel 9 to release a large amount of heat, and the excess oxidant in the first annular channel 9 is heated, so that the excess oxidant with high temperature can be formed, and the self-heating effect is achieved; but also to further transfer heat to the adjacent second annular channel 10 to heat the combustible carbonaceous waste in that channel, while the combustible carbonaceous waste, particularly the slurry, in the second annular channel 10 can be more easily ignited due to the high temperature excess oxidant generated, and gasification of the slurry can be promoted. While the oxidant in the third annular channel 11 facilitates the atomisation of the slurry and promotes the reaction. At the channel outlet, the outlets of the first, second and third annular channels are optimally designed to match the preferred outlet directions as described above, so that the materials output by the channels can be better contacted, the gasification reaction is sufficiently promoted, and the oxidant in the third annular channel 11 can promote the atomization of the slurry, so as to further promote the gasification reaction. The oxidant in the first 9 and third 11 annular channels of the burner 1 is conventional in the art, for example oxygen or an oxygen-containing gas, such as a gas having an oxygen content of more than 60% by volume, for example an oxygen content of 60-70% by volume.

In a specific application, during the gasification process, for example, the oxidant gas velocity in the first annular channel 9 can be controlled to be 100-; for example, the gas velocity of the waste flammable gas in the central annular passage may be controlled to about 50m/s (e.g., 45-55 m/s); the purge gas velocity of the purge device 4 may be controlled to be, for example, 0.2 to 0.5 m/s.

After reaction, the slag generated in the gasification chamber 2 flows downwards along the furnace wall to the vicinity of the slag tapping hole 5, is further reacted after being swept by the sweeping device 4 arranged below the slag tapping hole 5, and finally enters the chilling chamber 3 through the downcomer 6. As is conventional in the art, the syngas produced by the gasification reaction will enter downstream equipment after being scrubbed by the quench chamber 3, and will not be described in further detail.

In conclusion, the gasification furnace of the utility model can conveniently integrate combustible waste gas such as industrial combustible waste gas and solid carbon-containing waste into one gasification furnace for gasification so as to generate synthesis gas with more useful value. Thereby avoiding the energy waste and secondary pollution caused by directly using the wastes as fuel or landfill in the prior art. And based on the utility model discloses a gasifier can just utilize under the condition that the solid carbonaceous discarded object only carries out simple preliminary treatment, has simplified waste utilization's pretreatment process, changes the industrialization and implements and promote. Meanwhile, based on the gasification furnace of the utility model, through the ingenious structural design of the burner and the design of the purging device, the heat provided by the combustion of the self material can be fully utilized, the external heat input is reduced, the furnace drying time is reduced, the energy-saving effect is achieved, the carbonaceous waste can be more fully gasified, and the content of residual carbon is reduced; namely, the gasification effect and the energy utilization rate can be improved.

The following is further described with reference to specific application cases.

Example 1

Referring to fig. 1-5, gasification of carbonaceous waste is carried out using a gasification furnace as described above. Wherein, the wall thickness of the outlet end face of the central annular channel 8 of the gasification furnace is 0.5mm, the blowing port 16 is set to have an included angle of 45 degrees between the injection direction and the central shaft of the gasification furnace, and the injected blowing gas is water vapor with the temperature of 400 ℃; the outlet directions of the bottoms of the second annular channel 10 and the third annular channel 11 form an included angle of 55 degrees with the central axis of the burner 1.

In this embodiment, the combustible waste gas introduced into the central annular channel 8 of the burner 1 is coke oven gas, and the oxidant introduced into the first annular channel 9 and the third annular channel 11 is oxygen; the combustible carbonaceous waste introduced into the second annular channel 10 is slurry made of solid combustible carbonaceous waste and liquid combustible carbonaceous waste.

Wherein, in the slurry, the solid combustible carbon-containing waste is specifically carbon-containing sludge (the carbon content is about 70 percent), the liquid carbon-containing waste is specifically phenol-containing waste water, and before the slurry is prepared, the solid combustible carbon-containing waste is dried until the external water is 0 and is crushed to 75 mu m; the solid particles and liquid carbonaceous waste are mixed to make a slurry in which the volume percentage of solid particles is 50%.

During the gasification process, the following parameters are controlled within the following ranges: controlling the oxidant gas speed in the first annular channel 9 to be 100-150m/s, controlling the material speed of the second annular channel 10 to be 1-2m/s, and controlling the oxidant gas speed of the third annular channel 11 to be 100-150 m/s; controlling the gas velocity of the waste flammable gas of the central annular channel 8 to be about 50 m/s; the speed of the blowing gas of the blowing device 4 is controlled to be 0.2-0.5 m/s. After gasification, the residual carbon content of the slag is between 2 and 3 percent.

In addition, the inventor also develops that the livestock and poultry waste is used as solid combustible carbon-containing waste to be gasified based on the gasification furnace according to the same process of the embodiment 1, and the residual carbon content of the slag after gasification is between 2 and 3 percent.

Comparative example 1

A conventional gasification furnace in the field is adopted, wherein a burner is a three-channel burner, the oxidant is introduced into an outer ring channel and a central channel, the coal slurry is introduced into an annular gap channel between the outer ring channel and the central channel (the carbon content is similar to that in example 1), the gas velocity control of corresponding materials is the same as that in example 1, and the description is omitted. After gasification, the residual carbon content of the slag is higher and is between 7 and 8 percent.

It will be appreciated by those skilled in the art that certain modifications or adaptations to the invention may be made in light of the teaching of this specification. Such modifications or adaptations are intended to be within the scope of the present invention as defined by the claims.

Claims (7)

1. A gasification furnace for carbon-containing wastes comprises a gasification chamber and a chilling chamber arranged below the gasification chamber, wherein the bottom of the gasification chamber is provided with a slag discharge port, a down pipe vertically extending into the inner cavity of the chilling chamber is arranged right below the slag discharge port, the top of the gasification chamber is provided with a burner, and the gasification furnace is characterized in that,

the burner comprises a central annular channel for inputting combustible waste gas, a first annular channel for inputting an oxidant, a second annular channel for inputting combustible carbon-containing waste and a third annular channel for inputting the oxidant, which are sequentially sleeved from inside to outside, wherein the top of each channel is provided with an inlet, and the bottom of each channel is provided with an outlet;

a combustion space for the reaction of combustible waste gas and an oxidant is reserved between the outlet at the bottom of the central annular channel and the outlet at the bottom of the first annular channel;

the slag discharging device is characterized in that a purging device is installed between the slag discharging port and the descending pipe, purging ports used for spraying water vapor or carbon dioxide to slag falling through the slag discharging port are formed in the purging device, the purging ports are multiple, and the purging ports are distributed at equal intervals.

2. The carbonaceous waste gasification furnace according to claim 1, wherein the wall thickness of the central annular passage is thinned at the bottom outlet thereof, and the wall thickness of the outlet end face of the central annular passage is made to be 0.4mm to 0.6 mm.

3. The carbonaceous waste gasification furnace according to claim 1, wherein the purge port is provided so that the injection direction of the steam or the carbon dioxide is obliquely downward and the angle between the injection direction and the central axis of the gasification furnace is 30 to 45 degrees.

4. The carbonaceous waste gasification furnace according to claim 3, wherein the purge device comprises an annular purge line and a gas supply line connected to the annular purge line, the gas supply line being connected to a water vapor gas source or a carbon dioxide gas source;

the annular purging pipeline is provided with a plurality of purging ports.

5. The carbonaceous waste gasification furnace according to claim 4, wherein the annular purge conduit is a circular coil pipe, and the purge ports located on the same circumference are equally spaced.

6. The carbonaceous waste gasification furnace according to any one of claims 1 to 5, wherein the outlet direction of the bottom of the first annular passage is a vertical direction; and the outlet directions of the bottoms of the second annular channel and the third annular channel are both inclined downwards towards the central axis of the burner and form an included angle of 50-60 degrees with the central axis of the burner.

7. The carbonaceous waste gasification furnace according to any one of claims 1 to 5, wherein the combustible carbonaceous waste transported by the second annular channel is solid combustible carbonaceous waste or is a slurry of combustible carbonaceous waste.

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