A rotary furnace cover, furnace core and double reduction layer gasification furnace

Abstract

The present invention discloses a rotary furnace cover, furnace core and double reduction layer gasifier, the rotary furnace cover comprises a furnace cover, a furnace core and a driving mechanism, the driving mechanism is arranged on the furnace cover to drive the furnace cover to rotate; the top end of the furnace core is sleeved in the center hole of the furnace cover, so that the furnace core rotates with the furnace cover; a grate structure is arranged in the middle of the furnace core; the grate structure rotates with the furnace core, so that the material falls evenly on the grate structure, thereby realizing annular material distribution and material distribution in the gasifier; the bottom of the furnace core is provided with a slag scraping structure adapted to the bottom of the gasifier, so as to loosen and scrape off the ash and slag at the bottom of the furnace. The second and third air flow channels are arranged on the double reduction layer gasifier, so that the low temperature circulating gas entering the furnace cavity and the high temperature produced gas exiting the furnace cavity flow in the opposite direction, heat exchange is realized through the heat exchange of the partition wall, and heat energy is reasonably utilized; at the same time, the double reduction layer is realized by arranging the first air flow channel, the gas circulation mechanism and the air induced mechanism.

Description

Technical Field

[0001] This invention relates to the field of gasification furnace equipment technology, specifically a rotary furnace cover core and a double reduction layer gasification furnace. Background Technology

[0002] Small-scale gasifiers can convert waste or biomass into fuel gas on-site, avoiding large-scale centralized transfers of waste or biomass. They are well-suited for the small-scale centralized treatment and thermal energy utilization of widely distributed waste and biomass. In particular, they can prevent the accumulation of dioxins around the treatment furnace, which can cause irreparable permanent pollution, resulting from the centralized treatment of large amounts of waste.

[0003] Currently, small gasifiers generally use a fixed furnace bottom, which has the advantages of low investment and simple structure. However, fixed furnace bottom gasifiers generally have problems such as: slag formation making it difficult to remove slag, uneven distribution of feed material leading to easy burning of suspended material and unstable furnace conditions, and burn-through interruption of gasification. These problems limit the size of the furnace and prevent stable operation and continuous operation.

[0004] To address the problem of uneven material distribution, some gasifiers have added a top-mounted material leveling device, but this device has a complex structure, poor material leveling effect, high stress on the mechanism, and a high failure rate. Other gasifiers have a horizontally arranged eccentric crankshaft rod for material pressing. Although this device has a simple structure and stable operation, it cannot evenly distribute the material and can only prevent material from being suspended or burned through, and it also affects the stability of the furnace operation.

[0005] The difficulty in slag removal has always been a problem plaguing fixed-bottom gasifiers. In the previously developed top-suction gasifiers, slag clumps at the bottom were a major factor that prevented gasification from proceeding continuously. Some slag clumps were larger than rugby balls and were hard and difficult to break. Summary of the Invention

[0006] To address one or more shortcomings of the existing technologies, this invention provides a rotary furnace cover core and a double-reduction-layer gasifier, which not only enables annular material distribution and uniform material distribution within the gasifier, but also loosens and scrapes off ash and slag from the bottom of the gasifier, effectively preventing ash and slag from caking or forming clumps; the formation of a double-reduction layer improves gasification efficiency and makes rational use of thermal energy.

[0007] To achieve the above objectives, the present invention provides a rotating furnace lid core, comprising a furnace lid, a furnace core and a driving mechanism, wherein the driving mechanism is disposed on the furnace lid for driving the furnace lid to rotate;

[0008] The top end of the furnace core is fitted into the center hole of the furnace cover, and the bottom end extends downwards from the furnace cover so that the furnace core rotates with the furnace cover.

[0009] A grate structure is provided in the middle of the furnace core. The grate structure rotates with the furnace core so that the material falls evenly on the grate structure, thereby realizing the annular material distribution and uniform material distribution in the gasifier.

[0010] The bottom of the furnace core is equipped with a slag scraping structure adapted to the bottom of the gasifier, for scraping off the ash and slag from the bottom of the furnace.

[0011] In one embodiment, the grate structure includes a hollow fixed column, a hollow bracket, and a mesh grate plate. The fixed column is coaxially sleeved on the furnace core. There are multiple hollow brackets, which are distributed circumferentially on the fixed column. The mesh grate plate is disposed on the hollow bracket.

[0012] In one embodiment, the furnace core is provided with a first airflow channel 1 section that is connected to an external gas source, the hollow bracket is provided with a first airflow channel 2 section, and the fixed column is provided with a first airflow channel 3 section, and the first airflow channel 1 section, the first airflow channel 2 section, and the first airflow channel 3 section are connected in sequence.

[0013] The top plate of the hollow bracket is provided with a number of first air nozzles that communicate with the first airflow channel 2, and the outer wall of the fixed column is provided with a number of second air nozzles that communicate with the first airflow channel 3.

[0014] In one embodiment, the hollow bracket has a binary tree-like structure.

[0015] In one embodiment, the slag scraping structure includes at least one slag scraper, one end of which is connected to the bottom of the furnace core, and the other end extends obliquely upward toward the bottom of the furnace core.

[0016] To achieve the above objectives, the present invention also provides a dual-reduction-layer gasifier, comprising a furnace body with a top opening and the aforementioned rotating furnace cover core, wherein the furnace cover is rotatably connected to the opening at the top of the furnace body.

[0017] The furnace body is provided with a heat exchange mechanism, which includes a first shell and a second shell. The first shell is located on the outer wall of the furnace body, and the second shell is located in the space enclosed by the first shell and the furnace body. A second airflow channel is formed between the first shell and the second shell, and a third airflow channel is provided inside the second shell.

[0018] The first housing is provided with a first air inlet that communicates with one end of the second airflow channel, and the side wall of the furnace body is provided with a second air inlet that communicates with the other end of the second airflow channel. The second air inlet is located above the grate structure.

[0019] The second housing is provided with a first air outlet that communicates with one end of the third airflow channel, and the side wall of the furnace body is provided with a second air outlet that communicates with the other end of the third airflow channel. The second air outlet is located below the grate structure.

[0020] The shell wall of the second housing is a corrugated or threaded pipe to improve the heat exchange efficiency of the gas in the second and third airflow channels.

[0021] The first air outlet is equipped with an air intake mechanism, and the first air inlet is connected to the furnace cavity located above the grate structure through a circulation pipeline. The circulation pipeline is equipped with a gas circulation mechanism to draw the hot flue gas in the furnace cavity to the second airflow channel, so that the airflow entering the furnace cavity flows upward and downward under the action of the air intake mechanism and the gas circulation mechanism to form two reduction layers.

[0022] In one embodiment, the bottom of the furnace body has an irregular structure, which includes a constriction section and a slag discharge section. The top of the constriction section is connected to the side wall of the furnace body, and the slag discharge section is connected to the bottom of the constriction section.

[0023] The diameter of the constriction section decreases from the top to the bottom. The shape of the constriction section is matched with the slag scraping structure so that the slag scraping structure can scrape the ash and slag on the constriction section to the slag discharge section. The slag discharge section is provided with a slag discharge port.

[0024] In one embodiment, the slag discharge section is provided with a support member capable of supporting the furnace core, and the bottom end of the furnace core is in contact with the support member; the surface of the furnace core that contacts the support member is one of a spherical surface or a conical surface, and the surface of the support member that contacts the furnace core is the other of a spherical surface or a conical surface.

[0025] In one embodiment, an annular groove is provided on the outer wall of the furnace body near the top, and the bottom edge of the furnace cover is located in the annular groove; the annular groove is filled with high-temperature grease to provide sealing and lubrication between the furnace body and the furnace cover.

[0026] In one embodiment, the furnace body is provided with a feed pipe, one end of which is connected to the furnace cavity of the furnace body, and the other end extends obliquely downward to the furnace body; a third air outlet is provided on the top plate of the feed pipe, and the circulation pipeline is connected to the furnace cavity of the feed pipe through the third air outlet.

[0027] The present invention provides a rotary furnace cover core and a double reduction layer gasifier. By setting a furnace core that can rotate with the furnace cover, it can achieve annular material distribution and uniform material distribution, and scrape off ash and slag to prevent ash and slag from caking or forming clumps. By setting a first airflow channel, a gas circulation mechanism and an air intake mechanism, a double reduction layer is achieved. By setting a second and third airflow channels in the furnace body, the heat energy can be rationally utilized. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the rotary furnace lid core in an embodiment of the present invention;

[0030] Figure 2 This is a top view of the connection structure between the fixed column and the hollow bracket in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the gasifier in an embodiment of the present invention.

[0032] Reference numerals: Furnace cover 1, Furnace core 2, First airflow channel section 1 21, Drive mechanism 3, Fixed column 41, Mesh grate 42, Hollow bracket 43, First airflow channel section 2 44, First airflow channel section 3 45, First air nozzle 46, Second air nozzle 47, Guide baffle 48, Slag scraping structure 5, Furnace body 6, Closing section 61, Slag discharge section 62, Support component 63, Annular groove 64, Slag discharge port 65, First shell 71, Second shell 72, Second airflow channel 73, Third airflow channel 74, First air inlet 75, Second air inlet 76, First air outlet 77, Second air outlet 78, Corrugated pipe or threaded pipe 79, Exhaust fan 710, Circulation pipeline 711, Gas circulation mechanism 712, Feed pipe 8, Shaftless screw conveyor structure 81, Third air outlet 82.

[0033] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0036] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0037] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0039] like Figure 1-2 The diagram shows a rotating furnace lid core disclosed in this embodiment, specifically including a furnace lid 1, a furnace core 2, and a drive mechanism 3. The drive mechanism 3 is mounted on the furnace lid 1 to drive its rotation. In this embodiment, the drive mechanism 3 is a gear ring fitted onto the outer wall of the furnace lid 1. The gear ring can be a gear ring, a sprocket ring, or a toothed belt ring. Of course, the drive mechanism 3 in this embodiment is not limited to a gear ring drive; other drive methods that achieve the same effect, such as directly driving the furnace lid 1 with a rotating shaft, can also be used.

[0040] The top of the furnace core 2 is connected to the furnace cover 1, or it can pass through the furnace cover 1 and be located above the furnace cover 1. The bottom of the furnace core 2 extends downwards from the furnace cover 1. The furnace core 2 and the furnace cover 1 are fixedly connected, specifically by bolts, snap-fit ​​connections, or welding, so that the furnace core 2 can rotate with the furnace cover 1. Of course, the furnace cover 1 and the furnace core 2 can also be connected by a sliding key or similar method, so that the furnace core 2 can slide along the axial direction of the furnace cover 1 when rotating in the gasifier, thereby adapting to the thermal expansion and contraction of the various axial dimensions of the gasifier. More specifically, a grate structure is provided in the middle of the furnace core 2. The grate structure rotates with the furnace core 2, so that the material falls evenly on the grate structure, thereby achieving annular material distribution and uniform material distribution in the gasifier. The bottom of the furnace core 2 is provided with a slag scraping structure 5 connected to the bottom of the gasifier, for scraping off the ash and slag at the bottom of the furnace. It can not only effectively achieve annular material distribution and uniform material distribution in the gasifier, but also loosen and scrape off the ash and slag on the bottom of the gasifier through the rotation of the slag scraping structure 5, which can effectively prevent the ash and slag from caking or forming clumps.

[0041] In this embodiment, the grate structure includes a fixed column 41, a hollow bracket 43, a mesh grate plate 42, and a gas nozzle 46. The fixed column 41 is fitted onto the furnace core 2. Multiple hollow brackets 43 are distributed circumferentially around the fixed column 41. The mesh grate plate 42 is mounted on the hollow brackets 43. The fixed column 41, hollow brackets 43, and furnace core 2 are welded together. As the grate structure rotates with the furnace core 2, the material falls evenly onto the grate structure, achieving circular material distribution and uniform material distribution. Simultaneously, after the material burns into ash, the shaking during rotation effectively promotes the ash falling from the mesh of the mesh grate plate 42, thus preventing ash accumulation on the grate plate 42 and improving the combustion efficiency of the material on the grate plate 42.

[0042] In this embodiment, the furnace core 2 has a first airflow channel 1 section 21 connected to an external gas source, the hollow bracket 43 has a first airflow channel 2 section 44, and the fixed column 41 has a first airflow channel 3 section 45. The first airflow channel 1 section 21, the first airflow channel 2 section 44, and the first airflow channel 3 section 45 are connected sequentially. The top plate of the hollow bracket 43 has a first air nozzle 46 connected to the first airflow channel 2 section 44, and the outer wall of the fixed column 41 has a second air nozzle 47 connected to the first airflow channel 3 section 45. The first air nozzle 46 is located at the bifurcation and end points of the hollow bracket 43. The gasifying agent passes sequentially through the first airflow channel 1 section 21, the first airflow channel 2 section 44, and the first airflow channel 3 section 45, and then enters the material oxidation layer through the first air nozzle 46 and the second air nozzle 47, respectively. Preferably, the hollow bracket 43 is provided with a guide baffle 48 that divides the first airflow channel 2 section 44 into upper and lower layers, thereby increasing the path length of the airflow in the first airflow channel 2 section 44 and allowing the airflow to have a longer heat exchange time.

[0043] In this embodiment, the slag scraping structure 5 includes at least one slag scraper. One end of the scraper is connected to the bottom of the furnace core 2, and the other end extends obliquely upwards towards the bottom of the furnace core 2. Preferably, the slag scraping structure 5 in this embodiment includes two slag scraper plates symmetrically arranged at the bottom of the furnace core 2, and the bottom of the scraper plates has a serrated structure. The scraper plates are connected to the furnace core 2 by welding or integral molding. As the scraper plates rotate with the furnace core 2, they scrape off the ash and slag deposited at the bottom of the gasifier, thereby effectively preventing the ash and slag from caking or forming clumps, and solving the problem of difficult slag discharge from the gasifier.

[0044] In this embodiment, the gear ring is a high-ratio gear ring that can provide a speed ratio of at least 1:12, which can reduce the transmission force and effectively simplify the gasifier, thereby reducing costs.

[0045] refer to Figure 3 This embodiment discloses a dual-reduction-layer gasifier, which includes a furnace body 6 with a top opening and a rotating furnace cover core as described above. The furnace cover 1 in the rotating furnace cover core is rotatably connected to the opening at the top of the furnace body 6. The furnace body 6 is provided with a heat exchange mechanism, which includes a first shell 71 and a second shell 72. The first shell 71 is located on the outer wall of the furnace body 6, and the second shell 72 is located in the space enclosed by the first shell 71 and the furnace body 6. A second airflow channel 73 is formed between the first shell 71 and the second shell 72. A third airflow channel 74 is provided inside the second shell 72. Both the second airflow channel 73 and the third airflow channel 74 are inverted U-shaped structures, and the second airflow channel 73 is fitted above the third airflow channel 74. The first housing 71 is provided with a first air inlet 75 that communicates with one end of the second airflow channel 73, and the side wall of the furnace body 6 is provided with a second air inlet 76 that communicates with the other end of the second airflow channel 73. The second air inlet 76 is located above the grate structure. The second housing 72 is provided with a first air outlet 77 that communicates with one end of the third airflow channel 74, and the side wall of the furnace body 6 is provided with a second air outlet 78 that communicates with the other end of the third airflow channel 74. The second air outlet 78 is located below the grate structure. The shell wall of the second housing 72 is a corrugated pipe or a threaded pipe 79 to improve the heat exchange efficiency of the gas in the second airflow channel 73 and the third airflow channel 74. The first air outlet 77 is equipped with an air intake mechanism 710, and the first air inlet 75 is connected to the furnace cavity located above the grate structure through a circulation pipe 711. The circulation pipe 711 is equipped with a gas circulation mechanism 712 to draw the hot flue gas in the furnace cavity to the second airflow channel 73, and to make the airflow in the furnace cavity flow upward and downward under the action of the air intake mechanism 710 and the gas circulation mechanism 712 to form two reduction layers.

[0046] In this embodiment, the bottom of the furnace body 6 has an irregular shape, specifically including a constriction section 61 and a slag discharge section 62. The top of the constriction section 61 is connected to the side wall of the furnace body 6, and the slag discharge section 62 is connected to the bottom of the constriction section 61. The diameter of the constriction section 61 decreases from the top to the bottom, and its profile cooperates with the slag scraping structure 5 so that the slag scraping structure 5 can scrape the ash and slag on the constriction section 61 to the slag discharge section 62. The slag discharge section 62 is provided with a slag discharge port 65. Furthermore, the diameter of the constriction section 61 decreases uniformly from the top to the bottom to simplify the structure of the gasifier. In this embodiment, the distance between the bottom profile of the slag scraper plate (which serves as the slag scraping structure 5) and the profile of the constriction section 61 is approximately 5 mm. In this embodiment, the constriction section 61, the slag discharge section 62, and the side wall of the furnace body 6 are all connected by welding or integral molding.

[0047] In this embodiment, the slag discharge section 62 is provided with a support member 63 capable of supporting the furnace core 2, and the bottom end of the furnace core 2 is in contact with the support member 63. The surface of the furnace core 2 that contacts the support member 63 is either a spherical surface or a conical surface, and the surface of the support member 63 that contacts the furnace core 2 is either a spherical surface or a conical surface. Figure 2 As shown, the surface of the furnace core 2 that contacts the support member 63 is a conical surface, and the surface of the support member 63 that contacts the furnace core 2 is a spherical surface. This combination of conical and spherical surfaces not only enables the support member 63 to support the furnace core, but also reduces the contact area between the support member 63 and the furnace core 2, thereby reducing frictional resistance.

[0048] In this embodiment, an annular groove 64 is provided on the side wall near the top of the furnace body 6, and the bottom edge of the furnace cover 1 is located in the annular groove 64; the annular groove 64 is filled with high-temperature grease to provide sealing and lubrication between the furnace body 6 and the furnace cover 1.

[0049] In this embodiment, a feed pipe 8 is provided on the furnace body 6. One end of the feed pipe 8 is connected to the furnace cavity of the furnace body 6, and the other end extends obliquely downwards from the furnace body 6. A shaftless screw conveying structure 81 is provided in the feed pipe 8. The obliquely downward-sloping feed pipe 8 can effectively prevent water in the material from entering the gasifier. Preferably, a third air outlet 82 is provided on the top plate of the feed pipe 8. The circulation pipeline 711 is connected to the furnace cavity through the third air outlet 82 and the feed pipe 8, so that the hot flue gas in the furnace is extracted after passing through the feed pipe 8, so that there is a heat exchange process between the hot flue gas and the material, thereby realizing the pre-drying treatment of the material.

[0050] In this embodiment, the gasifier operates as follows: when the gear ring drives the furnace cover 1 and furnace core 2 to rotate at low speed, the scraper can immediately loosen the high-temperature slag that falls onto the closing part 61 and drive it to slide down to the slag discharge port 65 of the slag discharge part 62, and then discharge it through the screw ash discharge mechanism set at the slag discharge port 65. On the other hand, the waste or biomass material used as combustion material is fed into the grate structure in the furnace body 6 through the shaftless screw conveying structure 81 in the feed pipe 8, and the rotation of the grate structure realizes the ring distribution and uniform material distribution.

[0051] It is important to note that Figure 1 The arrows in the diagram indicate the airflow direction. The first airflow channel 1 section 21, the first airflow channel 2 section 44, and the first airflow channel 3 section 45 are the channels for the gasifying agent to enter the furnace body 6. The second airflow channel 73 is the gas circulation channel, and the third airflow channel 74 is the channel for the generated gas to exit the furnace body 6.

[0052] It is important to note that Figure 3 The solid arrows indicate the direction of the air entering the furnace, while the dashed arrows indicate the direction of the circulating airflow within the furnace.

[0053] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A rotary furnace cover core, characterized in that: It comprises a furnace cover, a furnace core and a driving mechanism, wherein the driving mechanism is arranged on the furnace cover to drive the furnace cover to rotate; The top end of the furnace core is sleeved in the center hole of the furnace cover, and the bottom end extends below the furnace cover, so that the furnace core rotates with the furnace cover; A grate structure is provided in the middle of the furnace core, and the grate structure rotates with the furnace core so that the material falls evenly on the grate structure, thereby realizing annular material distribution and uniform material distribution in the gasifier; The bottom of the furnace core is provided with a slag scraping structure adapted to the bottom of the gasifier furnace, so as to loosen and scrape off the ash and slag at the bottom of the furnace.

2. The rotary furnace cover core according to claim 1, characterized in that: The grate structure includes a hollow fixed column, a hollow bracket and a mesh grate plate. The fixed column is coaxially sleeved on the furnace core. There are multiple hollow brackets distributed on the fixed column at circumferential annular intervals. The mesh grate plate is arranged on the hollow bracket.

3. The rotary furnace cover core according to claim 2, characterized in that: The furnace core is provided with a first air flow channel 1 section connected to an external air source, the hollow bracket is provided with a first air flow channel 2 section, the fixed column is provided with a first air flow channel 3 section, and the first air flow channel 1 section, the first air flow channel 2 section, and the first air flow channel 3 section are connected in sequence; A plurality of first air nozzles connected to the second section of the first air flow channel are disposed on the top plate of the hollow bracket, and a plurality of second air nozzles connected to the third section of the first air flow channel are disposed on the outer side wall of the fixed column.

4. The rotary furnace cover core according to claim 3, characterized in that: The hollow bracket is a binary tree structure.

5. The rotary furnace cover core according to claim 1, characterized in that: The scraping structure comprises at least one scraping plate, one end of which is connected to the bottom of the furnace core, and the other end of which extends obliquely upward from the bottom of the furnace core.

6. A double reducing layer gasifier, characterized in that: A furnace body with an opening at the top and a rotary furnace cover and furnace core as claimed in any one of claims 1 to 5, wherein the furnace cover is rotatably connected to the opening at the top of the furnace body; The furnace body is provided with a heat exchange mechanism, which includes a first shell and a second shell, wherein the first shell is provided on the outer wall of the furnace body, and the second shell is provided in a space enclosed by the first shell and the furnace body; a second air flow channel is enclosed between the first shell and the second shell, and a third air flow channel is provided inside the second shell; The first shell is provided with a first air inlet connected to one end of the second air flow channel, the side wall of the furnace body is provided with a second air inlet connected to the other end of the second air flow channel, and the second air inlet is located above the grate structure; The second shell is provided with a first air outlet connected to one end of the third air flow channel, and the side wall of the furnace body is provided with a second air outlet connected to the other end of the third air flow channel, and the second air outlet is located below the grate structure; The shell wall of the second shell is a corrugated tube or a threaded tube, so as to improve the heat exchange efficiency of the gas in the second air flow channel and the third air flow channel; An air entrainment mechanism is provided on the first air outlet, and the first air inlet is connected to the furnace chamber located above the grate structure through a circulation pipeline. A gas circulation mechanism is provided on the circulation pipeline to draw the hot flue gas in the furnace chamber to the second air flow channel, and the air flow entering the furnace chamber flows upward and downward under the action of the air entrainment mechanism and the gas circulation mechanism to form two reduction layers.

7. The double reducing layer gasifier according to claim 6, characterized in that: The bottom end of the furnace body is a special-shaped structure, which includes a closing portion and a slag dropping portion, the top end of the closing portion is connected to the side wall of the furnace body, and the slag dropping portion is connected to the bottom end of the closing portion; The diameter of the closing portion decreases from the top to the bottom, and the profile of the closing portion cooperates with the scraping structure so that the scraping structure can scrape the ash on the closing portion to the slag dropping portion; the slag dropping portion is provided with a slag discharge port.

8. The double reducing layer gasifier according to claim 7, characterized in that: The slag dropping part is provided with a support member capable of supporting the furnace core, and the bottom end of the furnace core is in contact with and connected to the support member; the surface of the furnace core in contact with the support member is one of a spherical surface or a conical surface, and the surface of the support member in contact with the furnace core is the other of a spherical surface or a conical surface.

9. The double reducing layer gasifier according to claim 6, 7 or 8, characterized in that: An annular groove is provided on the outer wall of the furnace body near the top, and the bottom edge of the furnace cover is located in the annular groove; the annular groove is filled with high-temperature grease to achieve sealing and lubrication between the furnace body and the furnace cover.

10. The double reducing layer gasifier according to claim 6, 7 or 8, characterized in that: A feed pipe is provided on the furnace body, one end of which is connected to the furnace cavity of the furnace body, and the other end extends obliquely downward to the furnace body; a third air outlet is provided on the top plate of the feed pipe, and the circulation pipeline is connected to the furnace cavity through the third air outlet and the feed pipe.

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