Biomass fuel hot blast stove suitable for grain drying tower

Abstract

The utility model discloses a biomass fuel hot blast stove suitable for a grain drying tower, which relates to the technical field of biomass combustion drying equipment and comprises a hopper and a feeder, a discharge port of the hopper is communicated with a feed port of the feeder, a discharge port of the feeder is communicated with a main combustion area, and a fire grate is mounted below the main combustion area. The upper surface of the fire grate is located below a feeding port of the feeder. A gas outlet of the main combustion area is communicated with the particle separation area, and the particle separation area is sequentially communicated with the re-combustion area and the after-combustion area; a turbulent air pipe is communicated in the main combustion area; and a high-temperature air heat exchanger is mounted in the burnout area. The biomass fuel hot blast stove suitable for the grain drying tower is stable in combustion, high in heat efficiency, small in pollution and high in biomass fuel utilization rate.

Description

Technical Field

[0001] The utility model relates to the technical field of biomass combustion and drying equipment, in particular to a biomass fuel hot air furnace suitable for a grain drying tower. Background Art

[0002] Hot air furnaces are widely used in drying operations such as food and medicine. The fuel is mainly coal. Biomass fuel has its own advantages as a renewable energy source. The fuel itself has a low sulfur content and does not require desulfurization treatment after combustion. The use of scientific and reasonable low-nitrogen combustion technology can effectively control the emission of nitrogen oxides.

[0003] When biomass fuel is burned in the prior art, air containing a large amount of oxygen is provided in the main combustion zone. Rapid combustion in a short period of time generates local high temperature, which easily causes biomass ash to coke, resulting in incomplete combustion and the generation of a large amount of nitrogen oxides. In addition, grate coking often occurs, resulting in low heat exchange efficiency and flue blockage, requiring frequent regular cleaning, causing significant damage to equipment and making it impossible to operate continuously.

[0004] How to develop a biomass fuel hot air furnace suitable for grain drying towers, separate the flue gas, and recycle the ash to reduce the blockage of the flue in the later stage and improve the heat exchange efficiency has become a technical problem that needs to be solved urgently by technicians in this field. Utility Model Content

[0005] The purpose of the utility model is to provide a biomass fuel hot air furnace suitable for a grain drying tower, so as to solve the problems listed in the background technology.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The utility model discloses a biomass fuel hot air furnace suitable for a grain drying tower, comprising a hopper and a feeder, wherein the discharge port of the hopper is connected to the feed port of the feeder, the discharge port of the feeder is connected to the main combustion zone, a grate is installed below the main combustion zone, and the upper surface of the grate is located below the feed port of the feeder;

[0008] The gas outlet of the main combustion zone is connected to the particle separation zone, and the particle separation zone is connected to the reburning zone and the burnout zone in sequence;

[0009] The main combustion zone is connected with a turbulent air duct;

[0010] A high-temperature air heat exchanger is installed in the burnout zone.

[0011] Preferably, it further comprises a waste heat recovery zone, the air inlet of the waste heat recovery zone is connected to the air outlet of the burnout zone; a low-temperature air heat exchanger is installed inside the waste heat recovery zone, and the low-temperature air heat exchanger is connected to the air inlet of the combustion fan;

[0012] The air outlet of the waste heat recovery zone is communicated with the air inlet of the bag dust collector, and the air outlet of the bag dust collector is equipped with an induced draft fan.

[0013] Preferably, the high-temperature air heat exchanger is connected to the air inlet of the gasification fan.

[0014] Preferably, the particle separation zone includes a primary gas-solid separator and a secondary gas-solid separator, the air inlet of the primary gas-solid separator is connected to the air outlet of the main combustion zone, the biochar outlet of the primary gas-solid separator is connected to a biochar cooler, the primary separation gas outlet of the primary gas-solid separator is connected to the air inlet of the secondary gas-solid separator, and the secondary separation gas outlet of the secondary gas-solid separator is connected to the reburning zone; the circulating ash outlet of the secondary gas-solid separator is connected to a return material device;

[0015] One end of the material return device is communicated with the material return blower, and the other end of the material return device is communicated with the main combustion zone.

[0016] Preferably, the reburning zone is communicated with the air outlet of the staged combustion air duct, and the air inlet of the staged combustion air duct is communicated with the air outlet of the combustion blower.

[0017] Preferably, two turbulent air ducts are respectively provided on the side walls of the furnace in the main combustion zone, and the air outlets of the turbulent air ducts in the main combustion zone are relatively inclined, and the air inlets of the turbulent air ducts are connected to the air outlets of the gasification blower.

[0018] Compared with the prior art, the beneficial technical effects of the present invention are:

[0019] A biomass fuel hot blast furnace suitable for a grain drying tower can recover particulate matter in the fuel gas by setting a particle separation zone between the main combustion zone and the reburning zone, thereby fully utilizing biomass resources. Furthermore, the separated ash continues to participate in the combustion, and the ash is circulated and burned in a way that the ash in the fuel gas is fully burned, thus avoiding the ash clogging the flue. At the same time, the biomass fuel undergoes high-temperature cracking in the main combustion zone to generate high-temperature combustible gas, which enters the reburning zone after passing through the particle separation zone for full combustion, which can effectively reduce the concentration of pollutants in the fuel gas and is conducive to the exhaust gas discharged from the chimney meeting the standard. The heat after the high-temperature air heat exchanger and the low-temperature air heat exchanger work is recovered and continues to participate in the reaction between the main combustion zone and the reburning zone, so that the combustion of the hot blast furnace is stable, the thermal efficiency is high, the pollution is small, and the utilization rate of the biomass fuel is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1This is a schematic front view of a biomass fuel hot air furnace suitable for a grain drying tower according to the present invention; (section view)

[0022] Figure 2 This is a side view schematic diagram of the turbulent air duct of the utility model.

[0023] Description of the drawings: 1. Hopper; 2. Feeder; 3. Grate; 4. Main combustion zone; 5. Turbulent air duct; 6. Primary gas-solid separator; 7. Biochar cooler; 8. Secondary gas-solid separator; 9. Staged combustion air duct; 10. Return fan; 11. Return feeder; 12. Reburning zone; 13. High-temperature air heat exchanger; 14. Gasification fan; 15. Burnout zone; 16. Low-temperature air heat exchanger; 17. Combustion fan; 18. Bag dust collector; 19. Induced draft fan. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] like Figure 1-2 As shown, a biomass fuel hot air furnace suitable for a grain drying tower includes a hopper 1 and a feeder 2. The discharge port of the hopper 1 is connected to the feed port of the feeder 2, and the discharge port of the feeder 2 is connected to the main combustion zone 4. A grate 3 is installed below the main combustion zone 4. The upper surface of the grate 3 is located below the feed port of the feeder 2. The grate regularly discharges large particles of slag according to the pressure difference in the main combustion zone.

[0026] The biomass fuel in the hopper is placed on the grate through the feeder, and undergoes pyrolysis and gasification reaction under the high temperature conditions of the main combustion zone to produce combustible gases such as H2, CO, and CH4. At the same time, the main combustion zone adopts refractory lining structures such as red bricks, refractory bricks and refractory concrete, so that the main combustion zone does not absorb extra heat and is more adaptable to different moisture contents of biomass fuels;

[0027] The gas outlet of the main combustion zone 4 is connected to the particle separation zone, and the particle separation zone is connected to the reburning zone 12 and the burnout zone 15 in sequence. The particle separation zone can separate the burned particulate material from the gas to reduce flue blockage;

[0028] The main combustion zone 4 is connected to a turbulent air duct 5, and two turbulent air ducts 5 are respectively provided on the side walls of the furnace of the main combustion zone 4, and the air outlets of the turbulent air ducts 5 in the main combustion zone 4 are relatively inclined. The air inlet of the turbulent air duct 5 is connected to the air outlet of the gasification blower 14, which can form turbulence in the furnace of the main combustion zone;

[0029] A high-temperature air heat exchanger 13 is installed in the burnout zone 15. The high-temperature air heat exchanger 13 is connected to the air inlet of the gasification fan 14, and the high-temperature air in the high-temperature air heat exchanger is passed into the grain drying tower to participate in the grain drying operation inside the grain drying tower. The high-temperature air after drying is passed into the main combustion zone by the gasification fan through the turbulent air duct, ensuring a high-temperature environment inside the main combustion zone and pyrolyzing the biomass fuel into high-temperature combustible gas. The high-temperature air heat exchanger 13 adopts a tubular structure.

[0030] Specifically, it also includes a waste heat recovery zone, the air inlet of which is connected to the air outlet of the burnout zone 15; a low-temperature air heat exchanger 16 is installed inside the waste heat recovery zone, and the low-temperature air heat exchanger 16 is connected to the combustion fan 17, so that the gas enters the reburning zone after heat exchange with the combustion air, providing combustion support for the reburning zone;

[0031] The air outlet of the waste heat recovery area is connected to the air inlet of the bag dust collector 18. The bag dust collector can further collect fine dust in the fuel gas to reduce the dust content in the process of fuel gas discharge. The air outlet of the bag dust collector 18 is installed with an induced draft fan 19. The air outlet of the induced draft fan 19 is connected to the chimney to discharge the qualified gas after combustion and utilization.

[0032] Specifically, the particle separation zone includes a primary gas-solid separator 6 and a secondary gas-solid separator 8. The air inlet of the primary gas-solid separator 6 is connected to the air outlet of the main combustion zone 4, the biochar outlet of the primary gas-solid separator 6 is connected to the biochar cooler 7, the primary separation gas outlet of the primary gas-solid separator 6 is connected to the air inlet of the secondary gas-solid separator 8, and the secondary separation gas outlet of the secondary gas-solid separator 8 is connected to the reburning zone 12; the circulating ash outlet of the secondary gas-solid separator 8 is connected to the return material 11;

[0033] One end of the material return device 11 is connected to the material return fan 10, and the other end of the material return device 11 is connected to the main combustion zone 4;

[0034] The first-stage gas-solid separator can separate the large-particle bio-coke from the primary separation gas after combustion in the main combustion zone. The large-particle bio-coke is cooled in the biochar cooler and then collected.

[0035] The two-stage gas-solid separator can separate the circulating ash in the primary separated fuel gas from the secondary separated fuel gas. The circulating ash that does not need to be cooled enters the return device, and is supplied to the grate in the main combustion zone through the return fan to participate in combustion again. The separation effect of the two-stage gas-solid separator can greatly reduce the particulate matter content in the fuel gas, and can make the particulate matter in the fuel gas fully circulate and burn, avoiding ash clogging the flue.

[0036] Specifically, the reburning zone 12 is connected to the air outlet of the staged combustion air duct 9, and the air inlet of the staged combustion air duct 9 is connected to the air outlet of the combustion fan 17. After the secondary separated gas enters the reburning zone, it is fully burned and releases heat with the preheated air introduced by the combustion fan through the staged combustion air duct, which can greatly reduce the initial concentration of nitrogen oxides in the flue gas and is conducive to meeting emission standards.

[0037] The working process of this utility model:

[0038] Biomass fuel is pre-stored in a hopper for standby use and is placed on the grate in the main combustion zone through a feeder. After high-temperature pyrolysis, it generates combustible gas, which enters the particle separation zone. After separation in the first-level gas-solid separator and cooling and passivation in the biochar cooler, large-particle biochar is recovered. After passing through the second-level gas-solid separator, the small particles return to the main combustion zone for re-combustion, ensuring that the particulate matter in the fuel gas can fully react and reduce the particulate matter content in the fuel gas. The combustible gas after the second-level separation enters the reburning zone and fully burns and releases heat with the preheated air supplied by the staged combustion air duct. At this time, the fully burned fuel gas passes through the high-temperature air preheater and the low-temperature air preheater in sequence.

[0039] The heat exchange and drying operation is carried out through the high-temperature air heat exchanger and the grain drying tower, and the air after heat exchange and drying is supplied to the main combustion zone through the gasification fan and the turbulent air duct, maintaining the pyrolysis reaction environment inside the main combustion zone, so that the biomass fuel can be fully cracked to produce combustible gas; after passing through the low-temperature air preheater, the preheated air is passed through the combustion fan and the staged combustion air duct into the reburning zone to participate in combustion heat release and play a combustion-supporting role.

[0040] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or seal that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or seal.

[0041] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements to the technical solutions of the present invention made by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A biomass fuel hot air furnace suitable for a grain drying tower, comprising a hopper (1) and a feeder (2), wherein the discharge port of the hopper (1) is connected to the feed port of the feeder (2), and is characterized in that: The discharge port of the feeder (2) is in communication with the main combustion zone (4), a grate (3) is installed below the main combustion zone (4), and the upper surface of the grate (3) is located below the feed port of the feeder (2); The gas outlet of the main combustion zone (4) is connected to the particle separation zone, and the particle separation zone is connected to the reburning zone (12) and the burnout zone (15) in sequence; The main combustion zone (4) is connected to a turbulent air duct (5); A high-temperature air heat exchanger (13) is installed in the burnout zone (15).

2. The biomass fuel hot air furnace suitable for a grain drying tower according to claim 1, characterized in that: It also includes a waste heat recovery zone, the air inlet of the waste heat recovery zone is connected to the air outlet of the burnout zone (15); a low-temperature air heat exchanger (16) is installed inside the waste heat recovery zone, and the low-temperature air heat exchanger (16) is connected to the air inlet of the combustion fan (17); The air outlet of the waste heat recovery zone is communicated with the air inlet of the bag dust collector (18), and the air outlet of the bag dust collector (18) is equipped with an induced draft fan (19).

3. The biomass fuel hot air furnace suitable for a grain drying tower according to claim 1, characterized in that: The high-temperature air heat exchanger (13) is in communication with the air inlet of the gasification blower (14).

4. The biomass fuel hot air furnace suitable for a grain drying tower according to claim 1, characterized in that: The particle separation zone includes a primary gas-solid separator (6) and a secondary gas-solid separator (8), the air inlet of the primary gas-solid separator (6) is communicated with the air outlet of the main combustion zone (4), the biochar outlet of the primary gas-solid separator (6) is communicated with the biochar cooler (7), the primary separation gas outlet of the primary gas-solid separator (6) is communicated with the air inlet of the secondary gas-solid separator (8), and the secondary separation gas outlet of the secondary gas-solid separator (8) is communicated with the reburning zone (12); the circulating ash outlet of the secondary gas-solid separator (8) is communicated with the return material (11); One end of the material return device (11) is connected to the material return blower (10), and the other end of the material return device (11) is connected to the main combustion zone (4).

5. The biomass fuel hot air furnace suitable for a grain drying tower according to claim 2, characterized in that: The reburning zone (12) is in communication with the air outlet of the graded combustion air duct (9), and the air inlet of the graded combustion air duct (9) is in communication with the air outlet of the combustion blower (17).

6. The biomass fuel hot air furnace suitable for a grain drying tower according to claim 3, characterized in that: Two turbulent air ducts (5) are respectively provided on the side walls of the furnace of the main combustion zone (4), and the air outlets of the turbulent air ducts (5) in the main combustion zone (4) are relatively inclined, and the air inlets of the turbulent air ducts (5) are connected to the air outlets of the gasification blower (14).

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