阅读说明：本技术 一种下吸式生物质气化炉 (Downdraft biomass gasification furnace ) 是由 曾志伟 茹斌 宛政 郭泗勇 程文丰 崔洁 孙立 于 2020-06-12 设计创作，主要内容包括：本发明公开了一种下吸式生物质气化炉,包括：气化炉炉体；炉篦,所述炉篦设于所述气化炉炉体内；支撑组件,所述支撑组件设于所述气化炉炉体内下部,且所述支撑组件与所述炉篦固定连接并用于支撑所述炉篦；驱动机构,用于驱动所述支撑组件与所述炉篦旋转。本发明采用可连续运行的旋转炉篦结构设计,有效解决炉篦间断式排灰造成的系统周期性波动问题,提高系统运行的连续性和稳定性,增加系统整体效率。(The invention discloses a downdraft biomass gasification furnace, which comprises: a gasification furnace body; the fire grate is arranged in the gasification furnace body; the support assembly is arranged at the lower part in the gasification furnace body and is fixedly connected with the fire grate and used for supporting the fire grate; and the driving mechanism is used for driving the support component and the grate to rotate. The invention adopts the structural design of the rotary fire grate which can continuously operate, effectively solves the problem of periodic fluctuation of the system caused by intermittent ash discharge of the fire grate, improves the continuity and stability of the operation of the system and increases the overall efficiency of the system.)

1. A downdraft biomass gasifier, comprising:

a gasification furnace body;

the fire grate is arranged in the gasification furnace body;

the support assembly is arranged at the lower part in the gasification furnace body and is fixedly connected with the fire grate and used for supporting the fire grate;

and the driving mechanism is used for driving the support component and the grate to rotate.

2. The downdraft biomass gasifier of claim 1, further comprising disturbance ribs, wherein the grates are multi-layered and tower-shaped, gaps are provided between the grates, and the grates are connected by the disturbance ribs.

3. The downdraft biomass gasification furnace according to claim 2, wherein the disturbance rib has a trapezoidal shape, and a height of the disturbance rib near a center of the grate gradually increases or decreases in a clockwise direction, and a height of the disturbance rib near an edge of the grate gradually decreases or increases in a clockwise direction.

4. The downdraft biomass gasifier of claim 1, wherein the driving mechanism includes a pair of intermeshing gear sets disposed within a gasifier body, and a motor disposed outside the gasifier body, wherein a first gear of the gear sets is driven by the motor such that a second gear of the gear sets drives the support assembly and the grate to rotate.

5. The downdraft biomass gasification furnace according to claim 4, wherein the first gear is connected to the motor through a transmission shaft.

6. The downdraft biomass gasifier of claim 1, wherein the support assembly includes an upper support and a lower support, the upper support being disposed above the second gear for supporting the grate; the lower support body is arranged below the second gear and used for supporting the second gear.

7. The downdraft biomass gasifier of claim 6, wherein the lower support body includes a support body and a support rod, the support body being connected to the second gear for supporting the second gear; the support rod is connected below the support body and used for supporting the support body.

8. The downdraft biomass gasifier according to claim 1, further comprising an ash bearing table, wherein the ash bearing table is fixedly disposed on an inner wall of the gasifier body and is close to a lower portion of the edge of the grate.

9. The downdraft biomass gasification furnace according to claim 8, further comprising an ash scraping knife disposed on the support assembly and located between the grate and the ash receiving platform for scraping off ash from the ash receiving platform.

Technical Field

The invention relates to the technical field of biomass energy, in particular to a downdraft biomass gasifier.

Background

The biomass is a clean, abundant and only carbon-containing renewable energy source, can well solve the world problems of energy shortage and environmental pollution, and is increasingly widely concerned. The thermochemical utilization of biomass is to perform combustion, pyrolysis, gasification and other treatments on biomass under high temperature conditions to obtain products such as heat, electricity or combustible gas, wherein the biomass gasification technology has the advantages of rapid reaction, high conversion efficiency, flexible end products, easy industrialization and the like, and has become a key point of world research. The biomass gasification technology mainly comprises fluidized bed gasification and fixed bed gasification. The common fixed bed gasification furnaces are divided into an updraft type gasification furnace, a downdraft type gasification furnace, an open-center type gasification furnace and the like, and compared with updraft type gasification technologies and other gasification technologies, the downdraft type fixed bed gasification furnace has relatively low tar content, but the requirements of terminal power generation are difficult to meet, and further improvement is needed.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a downdraft biomass gasification furnace, which comprises:

a gasification furnace body;

the fire grate is arranged in the gasification furnace body;

the support assembly is arranged at the lower part in the gasification furnace body and is fixedly connected with the fire grate and used for supporting the fire grate;

and the driving mechanism is used for driving the support component and the grate to rotate.

Preferably, the downdraft biomass gasification furnace may further include disturbance fins, the grates are in a multi-layer tower-shaped structure, gaps are formed between the grates, and the grates are connected through the disturbance fins.

Further preferably, the disturbing rib is trapezoidal, the height of the disturbing rib close to the center of the grate gradually increases or decreases in the clockwise direction, and the height of the disturbing rib close to the edge of the grate gradually decreases or increases in the clockwise direction.

Preferably, the driving mechanism comprises a pair of gear sets engaged with each other and arranged in the gasification furnace body, and a motor arranged outside the gasification furnace body, wherein a first gear of the gear set is driven by the motor, so that a second gear of the gear set drives the support assembly and the grate to rotate.

Further preferably, the first gear is connected with the motor through a transmission shaft.

Preferably, the support assembly comprises an upper support body and a lower support body, and the upper support body is arranged above the second gear and used for supporting the fire grate; the lower support body is arranged below the second gear and used for supporting the second gear.

Further preferably, the lower supporting body comprises a supporting body and a supporting rod, and the supporting body is connected with the second gear and is used for supporting the second gear; the support rod is connected below the support body and used for supporting the support body.

Preferably, the downdraft biomass gasifier further comprises an ash bearing table, wherein the ash bearing table is fixedly arranged on the inner wall of the gasifier body and is close to the lower part of the edge of the grate.

Further preferably, the downdraft biomass gasifier further comprises an ash scraping knife, wherein the ash scraping knife is arranged on the supporting assembly and positioned between the grate and the ash bearing table and used for scraping ash on the ash bearing table.

The rotary fire grate structure design adopted by the invention enables the fire grate to continuously discharge ash for operation, can effectively solve the problem that the traditional fire grate causes the whole periodic fluctuation of the biomass gasification system due to intermittent ash discharge, improves the continuity and stability of the whole operation of the system and increases the whole efficiency of the system. The grate adopts the layered structure design, can increase the radial circulation passageway of gasification gas medium on the raw materials layer, improves the homogeneity of gasification medium at the circulation of raw materials layer, reduces biomass gasification system short circuit and local reaction and worsens the risk, improves gasification reaction efficiency. In addition, the irregular disturbance fins arranged on the surface of the grate can strengthen the disturbance and stirring effect of the grate on the raw material layer, and optimize the uniform distribution of the raw material layer and the uniform gas-solid reaction.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the apparatus and method consistent with the invention and, together with the detailed description, serve to explain the advantages and principles consistent with the invention. In the drawings:

FIG. 1 is a schematic cross-sectional view of a downdraft biomass gasifier according to an embodiment of the present invention;

FIG. 2 is a schematic side view of another multi-layered grate in a downdraft biomass gasifier according to an embodiment of the present invention;

FIG. 3 is a schematic view of a disturbance fin structure in a downdraft biomass gasifier according to an embodiment of the present invention;

fig. 4 is a schematic top view of a multi-layer grate in a downdraft biomass gasification furnace according to an embodiment of the present invention.

Description of the reference numerals

1-a gasification furnace body;

2-a raw material layer;

3-scraping the ash knife;

4-upper support;

5-a first gear;

6-a transmission shaft;

7-a motor;

8-disturbance fins;

9-grate;

10-ash bearing table;

11-gas outlet;

12-a second gear;

13-a support body;

14-a support bar;

15-ash outlet;

16-ash bin.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other, and the technical idea of the present invention may be implemented in combination with other known techniques or other techniques identical to those known techniques.

Referring to fig. 1, the present embodiment provides a downdraft biomass gasifier including:

a gasification furnace body 1;

the fire grate 9, the said fire grate 9 locates in the said gasification furnace body 1;

the support assembly is arranged at the lower part in the gasification furnace body and is fixedly connected with the fire grate 9 and used for supporting the fire grate;

and the driving mechanism is used for driving the support component and the grate to rotate.

In this embodiment, the biomass raw material and the gasification medium are introduced into the gasification furnace together from the top of the gasification furnace, wherein the biomass raw material may be a granular biomass raw material, and the gasification medium may be air or the like. The biomass raw material falls on the grate to form a stable raw material layer 2, and the gasification medium uniformly passes through the raw material layer 2 and performs oxidation-reduction reaction with the raw material layer to generate gasification gas. The gasification gas generated after the reaction passes through the grate 9 through the gaps of the grate 9 and the gaps between the grate 9 and the gasification furnace body 1, and is discharged out of the furnace through the gas outlet 11 at the lower part of the grate 9. The residual biomass ash after reaction can be discharged into an ash bin 16 through the rotary grate 9 and finally discharged out of the gasifier body 1 through an ash outlet 15 at the bottom of the ash bin 16.

Referring to fig. 1 to 2, in the downdraft biomass gasification furnace according to the present embodiment, the grate 9 may be a plurality of layers, for example, two layers of grates as shown in fig. 1, or three layers of grates as shown in fig. 2, the heights of the grates of the respective layers may be the same, the grates 9 of the respective layers are in a tower-like structure, gaps are provided between the grates of the respective layers, the grates of the respective layers are connected by the disturbance ribs 8, and the heights of the gaps between the grates of the respective layers may be the same. The gasification gas generated after the reaction can pass through the grate 9 through the gaps between the grates of each layer and is discharged out of the gasification furnace through the gas outlet 11 at the lower part of the grate.

Referring to fig. 1, 3 and 4, in the gasification furnace provided by the present embodiment, the disturbance rib 8 is trapezoidal, and the height of the disturbance rib 8 near the center of the grate 9 gradually increases or decreases in the clockwise direction, and the height of the disturbance rib 8 near the edge of the grate 9 gradually decreases or increases in the clockwise direction. Referring to fig. 3, the disturbance rib 8 has a trapezoidal overall structure, and the inclined side L3 is fixedly connected to the surface of the grate 9. The height L1 of the disturbing rib 8 near the centre of the grate 9 increases gradually in a clockwise direction and the height L2 of the disturbing rib 8 near the edge of the grate 9 decreases correspondingly, so that an irregular rib arrangement is formed. Furthermore, the disturbance ribs 8 may be provided in an even number, and as shown with reference to fig. 4, the disturbance ribs 8 are provided in four, evenly arranged on the multi-layer grate 9. The height L1 of the disturbing rib 8 near the centre of the grate 9 may gradually increase in a clockwise direction by 5cm, 10cm, 15cm, 20cm, and the height L2 of the disturbing rib 8 near the edge of the grate 9 may gradually decrease by 20cm, 15cm, 10cm, 5cm, respectively.

In this embodiment, the driving mechanism may include a pair of gear sets engaged with each other and disposed inside the gasification furnace body, wherein the first gear 5 of the gear set is driven by the motor 7 disposed outside the gasification furnace body 1, so that the second gear 12 of the gear set drives the support assembly and the grate 9 to rotate. Further, the first gear 5 is connected with the motor 7 through a transmission shaft 6, and the motor 7 can be connected with the transmission shaft 6 through a chain. The motor 7 is arranged outside the gasifier body 1, so that the influence of high temperature in the gasifier body 1 on the motor 7 can be avoided, and the service life of the motor is effectively prolonged.

In this embodiment, the supporting assembly may comprise an upper supporting body 4 and a lower supporting body, the upper supporting body 4 is disposed above the second gear 12 for supporting the fire grate 9; the lower support is disposed below the second gear 12 and is used for supporting the second gear. The supporting component with split design can more pertinently play a supporting role, and the driving force of the needed motor 7 is reduced.

Further, the lower support body comprises a support body 13 and a support rod 14, wherein the support body 13 is connected with the second gear 12 and is used for supporting the second gear 12; the support rod 14 is connected to the lower part of the support body 13 and is used for supporting the support body 13.

Further, the downdraft biomass gasifier provided by the embodiment may further include an ash bearing table 10, where the ash bearing table 10 is fixedly disposed on the inner wall of the gasifier body 1 and is close to the lower side of the edge of the grate 9. Still preferably, the downdraft biomass gasifier may further include an ash scraper 3, the ash scraper 3 is disposed on the support assembly and located between the grate 9 and the ash bearing table 10, and is configured to scrape off ash on the ash bearing table 10, and the ash scraper 3 may be welded to the upper support 4 by a welding method. After the reaction of the biomass raw materials, ash slag generated by the reaction falls on the ash bearing platform 10 along the edges of the multiple layers of grates 9, and the ash scraping knife 3 rotates along with the rotation of the multiple layers of grates to scrape the ash slag on the ash bearing platform 10 to the ash bin 16, so that continuous ash discharge is realized. An ash outlet 15 is arranged at the bottom of the ash bin 16, and biomass ash is continuously conveyed out of the furnace in a packing auger mode.

In the operation process of the embodiment, the multilayer grate rotates continuously, the biomass gasification furnace system discharges ash continuously, the rotating speed of the grate 9 is adjusted to meet the dynamic balance of feeding and ash discharging of the gasification furnace, the height of a raw material layer of about 50cm can be maintained, the temperature of the raw material layer is about 700 ℃, the pressure difference of the raw material layer is maintained at about-1000 pa, and the stability of the operation condition in the furnace is ensured.

The rotary fire grate structure design adopted by the invention enables the fire grate 9 to continuously discharge ash for operation, can effectively solve the problem that the traditional fire grate causes the whole periodic fluctuation of the biomass gasification system due to intermittent ash discharge, improves the continuity and stability of the whole operation of the system and increases the whole efficiency of the system. The grate 9 adopts the layered structure design, can increase the radial circulation passageway of gasification gas medium on the raw materials layer, improves the homogeneity of gasification medium at the circulation of raw materials layer, reduces biomass gasification system short circuit and local reaction and worsens the risk, improves gasification reaction efficiency. In addition, the irregular disturbance fins 8 arranged on the surface of the grate 9 can strengthen the disturbance and stirring effect of the grate 9 on the raw material layer 2, and optimize the uniform distribution of the raw material layer 2 and the uniform gas-solid reaction.

The terms "first" and "second" as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, unless otherwise specified. Similarly, modifiers similar to "about", "approximately" or "approximately" that occur before a numerical term herein typically include the same number, and their specific meaning should be read in conjunction with the context. Similarly, unless a specific number of a claim recitation is intended to cover both the singular and the plural, and also that claim may include both the singular and the plural.

In the description of the above specific embodiments, the terms "thickness", "upper", "lower", "vertical", "parallel", "bottom", "angle", and the like, indicate an orientation or positional relationship based on that shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that these are by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.