Multi-fuel low-nitrogen combustion hot blast stove

Abstract

The present application relates to hot blast stove technical field, specifically relates to low nitrogen combustion hot blast stove of multiple type fuel, be provided with solid-liquid gas three in one combustor in hot blast stove and be connected with hot blast chamber, three modes, air all adopts preheated air and mixed air intake mode of circulating tail gas, realize oxygen deficiency and low temperature combustion, gas passes through mixed chamber three stage air distribution, realizes uniform mixing, carries out fluidization to solid fuel, guarantees combustion effect, carries out atomization to liquid fuel, makes it fully burn, and adopts fine structure, improves combustion efficiency, guarantees combustion effect and prevents blockage, guarantees the stable operation of combustor, the air of combustor is combusted in two sections through hot blast chamber, the mode of segmented combustion, effectively reduces combustion temperature, reduces the generation of high temperature combustion nitrogen, realizes low nitrogen combustion and emission, the present application is reasonable in design, stable in operation, realizes low nitrogen combustion of solid-liquid gas three types of fuel, makes the applicability of hot blast stove wider, also meets the requirements of environmental protection and times.

Description

Technical Field

[0001] This invention relates to the field of hot blast stove technology, and more specifically to hot blast stoves with low-NOx combustion of various fuels. Background Technology

[0002] Hot blast stoves are thermal power machines that began to be widely used in my country in the late 1970s. They have become a replacement for electric heat sources and traditional steam power sources in many industries. Hot blast stoves come in many varieties and series, and are classified into hand-fired and machine-fired types according to the method of coal feeding, and into coal, oil, and gas stoves according to the type of fuel.

[0003] Existing hot blast stoves typically achieve low-NOx combustion through methods such as air staging, fuel staging, flue gas recirculation, swirl impact premixing, or a combination of these technologies. These techniques address the high-temperature combustion nitrogen generated during combustion (referring to the oxidation of N2 in the air at high temperatures) caused by the Zeldowicz mechanism. The formation of thermal nitrogen is suppressed by controlling the combustion flame temperature; for example, CN110513887A discloses an ultra-low NOx emission gas-fired hot blast stove. By controlling the formation of high-temperature combustion nitrogen, nitrogen emissions are effectively reduced, thus achieving environmental protection.

[0004] However, existing hot air furnaces are often only suitable for one type of fuel, such as gas-fired hot air furnaces, which generate hot air by burning gas in conjunction with a burner. But they are no longer suitable for raw materials such as biomass. As biomass and other energy sources receive more and more attention, how to improve the applicability of existing hot air furnaces to keep up with the times is an issue that contemporary business people cannot ignore and a relentless pursuit. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-type low-NOx combustion hot blast stove to solve the problem that existing hot blast stoves are often only applicable to one type of raw material, have poor applicability, and conflict with the concept of resource conservation and regeneration.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a multi-type fuel low-NOx combustion hot air furnace, including a shell, a support is provided below the shell, a burner and a hot air chamber are provided in the shell, the burner is a solid-liquid-gas three-in-one burner, an air inlet pipe is provided at the bottom of the burner, an air outlet pipe is provided above the burner, and the air outlet pipe is connected to the hot air chamber.

[0007] Furthermore, the burner is provided with a combustion chamber, and a mixing chamber is provided below the combustion chamber. The mixing chamber is inverted conical in shape. The air inlet pipe is located at the bottom of the mixing chamber. An air inlet pipe and a circulating air pipe are provided on the side wall of the mixing chamber. The air inlet pipe delivers gaseous fuel. The inlets of the air inlet pipe and the circulating air pipe are tangent to the chamber wall of the mixing chamber. At the same time, the air inlet pipe and the circulating air pipe are respectively arranged on both sides of the mixing chamber. A wind deflector is provided in the combustion chamber. The wind deflector is conical in shape. An air outlet is provided above the wind deflector. The air outlet pipe is located on the combustion chamber wall above the wind deflector.

[0008] Furthermore, the air intake pipe and the circulating air pipe are each equipped with a Venturi tube A, and the Venturi tube A is connected to the air intake pipe through the air intake pipe A.

[0009] Furthermore, a liquid distribution chamber is provided above the combustion chamber, and the liquid distribution chamber is connected to the liquid inlet pipe above it. The liquid inlet pipe delivers liquid fuel, and an atomizing nozzle is installed below the liquid distribution chamber. A cyclone plate is arranged around the inner periphery of the air outlet.

[0010] Furthermore, a Venturi tube B is provided on the liquid inlet pipe, and the Venturi tube B is connected to the air inlet pipe through the suction pipe B.

[0011] Furthermore, an air distribution plate is provided between the combustion chamber and the mixing chamber, and an air cap is arranged on the air distribution plate. A feed pipe is provided above the combustion chamber to transport solid fuel. The feed pipe passes through the liquid distribution chamber and extends to the bottom of the air outlet. A slag discharge channel is provided at the bottom of the combustion chamber.

[0012] Furthermore, a baffle is provided in the hot air cavity, and an air distribution cavity is provided in the baffle. The air outlet pipe is connected to one side of the air distribution cavity, and the other side of the air distribution cavity is connected to the combustion chamber. Air distribution holes are arranged on the side plate between the air distribution cavity and the combustion chamber, forming a heat exchange air cavity between the combustion chamber and the shell. An air inlet is provided at one end of the heat exchange air cavity, and the other end of the heat exchange air cavity is connected to the combustion chamber through the air inlet. The combustion chamber and the heat exchange air cavity exchange heat in opposite directions.

[0013] Furthermore, a spiral baffle is provided in the heat exchange air cavity.

[0014] Furthermore, the air inlet is connected to the jet pipe, which is arranged at an angle toward the direction of air outlet from the air distribution chamber.

[0015] Furthermore, the heat exchange air chamber is provided with a vent on the baffle, the vent is connected to the air duct, the air duct is connected to the air inlet pipe, and a flow display and controller is installed on the air duct.

[0016] The beneficial effects of this invention are:

[0017] 1. It can achieve multiple types of combustion, making it more convenient to use and more widely applicable;

[0018] 2. By using oxygen-deficient combustion, exhaust gas recirculation, and staged combustion, heat control during combustion is achieved, which effectively reduces the generation of nitrogen during high-temperature combustion, thus achieving low-NOx combustion and emissions;

[0019] 3. The burner operates stably, and its refined structure effectively prevents dust accumulation and blockage, which is beneficial to the safe and stable operation of production. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the overall structure of the combustion furnace of the present invention (frontal perspective, three-dimensional view);

[0022] Figure 3 This is a schematic diagram of the overall structure of the combustion furnace of the present invention (right perspective).

[0023] Figure 4 This is a schematic diagram showing the connection relationship between the liquid inlet pipe and the air inlet pipe of the present invention;

[0024] Figure 5 This is a schematic diagram of the left end cap structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the nozzle arrangement at the lower part of the liquid distribution chamber of the present invention;

[0026] Figure 7 This is a schematic diagram of the internal structure of the windshield of the present invention;

[0027] Figure 8 This is a schematic diagram of the overall structure of the hot air cavity of the present invention;

[0028] Figure 9 This is a schematic diagram of the internal air distribution cavity structure of the partition of the present invention.

[0029] The names corresponding to each mark in the diagram:

[0030] 1. Shell; 11. Support; 12. End cap; 121. Slag discharge port; 2. Burner; 21. Combustion chamber; 211. Air outlet pipe; 212. Feed pipe; 22. Mixing chamber; 221. Air inlet pipe; 222. Air intake pipe; 223. Circulating air pipe; 224. Venturi tube A; 225. Suction pipe A; 23. Liquid distribution chamber; 231. Liquid inlet pipe; 232. Venturi tube B; 233. Suction pipe B; 234. Atomizing nozzle; 24. 241. Air distribution panel; 25. Wind cap; 251. Wind shield; 252. Conical cover; 253. Air outlet; 254. Cyclone vane; 3. Air duct; 31. Flow display controller; 4. Hot air chamber; 41. Baffle; 411. Ventilation opening; 412. Connection port; 413. Air distribution chamber; 414. Air distribution hole; 42. Combustion chamber; 421. Air inlet; 422. Jet pipe; 43. Heat exchange air chamber; 431. Air inlet; 432. Spiral baffle. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] Example:

[0033] like Figures 1-9 As shown, the hot air furnace of the present invention includes a shell 1, a cap 12 at the left end of the shell 1, a burner 2 on the left side of the shell 1, a combustion chamber 21 within the burner 2, a mixing chamber 22 below the combustion chamber 21, a liquid distribution chamber 23 above the combustion chamber 21, and an air distribution plate 24 between the combustion chamber 21 and the mixing chamber 22. An air hood 241 is arranged on the air distribution plate 24. The mixing chamber 22 is inverted conical in shape, with the bottom of the mixing chamber 22... The mixing chamber 22 is connected to the air inlet duct 221 and has an air inlet duct 222 and a circulating air duct 223 on the side wall. The air inlet duct 222 and the circulating air duct 223 are respectively arranged on both sides of the mixing chamber 22. The inlets of the air inlet duct 222 and the circulating air duct 223 are tangent to the chamber wall of the mixing chamber 22. Venturi tubes A224 are respectively installed on the air inlet duct 222 and the circulating air duct 223. The Venturi tubes 224 are connected to the air inlet duct 221 through the suction pipe A225.

[0034] A wind deflector 25 is provided in the combustion chamber 21, and a conical shroud 251 is provided in the wind deflector 25. An air outlet 252 is provided above the conical shroud 251. The wind deflector 25 divides the combustion chamber 21 into upper and lower parts. The lower part is used for the combustion of solid fuels, and the upper part is used for the combustion of liquid fuels. The entire combustion chamber 21 can be used for the combustion of gaseous fuels. An air outlet 211 is arranged above the wind deflector 25, and a cyclone plate 253 for rotating the airflow is provided at the air outlet 252.

[0035] A liquid inlet pipe 231 is provided on the liquid distribution chamber 23. The inlet of the liquid inlet pipe 231 is located outside the left end cap 12. An atomizing nozzle 234 is arranged below the liquid distribution chamber 231. A venturi tube B232 is provided on the liquid inlet pipe 231. The venturi tube B232 is connected to the air inlet pipe 221 through the air intake pipe B233.

[0036] A feed pipe 212 is provided on the liquid distribution chamber 23. The feed pipe 212 passes through the liquid distribution chamber 23 but is not connected to the liquid distribution chamber 23. The outlet of the feed pipe 212 extends to the bottom of the air outlet 252.

[0037] The air outlet duct 211 is connected to the hot air chamber 4, in which a baffle 41 is provided and a distribution air chamber 413 is provided in the baffle 41. The air outlet duct 211 is connected to the distribution air chamber 413 through the connection port 412 on the left side of the distribution air chamber 415, and a distribution air hole 414 is arranged on the right side plate of the distribution air chamber 413.

[0038] The air distribution chamber 415 is connected to the combustion chamber 42. A heat exchange air chamber 43 is provided between the combustion chamber 42 and the shell 1. The heat exchange air chamber 43 has an air inlet 431 on the shell 1 and a spiral baffle 432 in the heat exchange air chamber 43. The left end of the heat exchange air chamber 43 is sealed by a baffle 41. An air inlet 421 is provided between the heat exchange air chamber 43 and the combustion chamber 42. The air inlet 421 is arranged in a ring on the chamber wall of the combustion chamber 42 and is connected to the jet pipe 422.

[0039] A vent 411 is provided on the baffle 41. The vent 411 is connected to the air inlet pipe 221 through the air duct 3. A flow display controller 31 is installed on the air duct 3.

[0040] The principle of this invention is as follows:

[0041] This invention can be applied to three types of fuels: gas, liquid, and solid, such as natural gas, fuel oil, coal, and biomass.

[0042] For gaseous fuels, preheated air is introduced into the burner 2 through the air inlet pipe 221. At the same time, gas is introduced into the burner 2 through the air inlet pipe 222, and the exhaust gas is circulated through the circulating air pipe 223. During the process, the flow display controller 31 on the air pipe 3 is used to control the air volume. At the same time, the pipes connected to the air inlet pipe 222 and the circulating air pipe 223 are also equipped with flow control valves to control the gas intake volume and the circulating air volume, so that the gas burns in an oxygen-deficient state, reducing the combustion temperature and thus reducing the production of high-temperature combustion nitrogen. On the other hand, the circulating air is the circulating exhaust gas, and the main component of the exhaust gas is nitrogen, which is equivalent to an inert gas. The exhaust gas temperature is low, which plays a role in absorbing heat and also helps to reduce the combustion temperature and reduce the production of high-temperature combustion nitrogen.

[0043] In this invention, the fuel gas, recirculated exhaust gas, and intake air are mixed three times in the mixing chamber 22, resulting in a more uniform mixture that is beneficial for uniform combustion in the subsequent combustion chamber 21. During this process, air is drawn into the fuel gas and recirculated exhaust gas through the venturi tube A224 for initial mixing. After the fuel gas and recirculated exhaust gas enter the mixing chamber 22, due to their tangential entry, they are in a spiral state with opposite directions. Under the impact of the airflow, the three gases undergo a second mixing. After this second mixing, the mixing effect is quite uniform. The mixed gas then passes through the air distributor 24 (flow... The gas is mixed a third time using a chemical bed air distribution plate (a mature existing technology), ultimately achieving a uniform mixture of the three gases, which then flows into the combustion chamber 21 for combustion. The combustion of the gas is mainly concentrated below the wind deflector 25. During the process, the wind deflector 25 can block and deflect the airflow, thus making the combustion more complete. A small amount of combustion occurs above the wind deflector 25 because some air enters the cavity above the wind deflector 25 through the intake pipe B233, the liquid inlet pipe 231, the liquid distribution chamber 23, and the atomizing nozzle 234, thereby further burning the unburned gas in the upper part. The hot air after combustion is led out through the exhaust pipe 211.

[0044] For the combustion of solid fuel, solid material enters the cavity below the wind baffle 25 through the feed pipe 212. A rotary valve can be used to add solid fuel, ensuring effective system sealing while adding material. The solid material is added below the air outlet 252, concentrating combustion below the wind baffle 25. Hot air is then introduced through the air inlet pipe 221, and recirculated exhaust gas is introduced through the recirculation pipe 223. This causes the introduced solid material to be fluidized on the air distribution plate 24. During this process, the appropriate airflow and velocity need to be determined based on the material's properties. When the airflow force and the weight of the material are essentially offset, the solid fuel is in a fluidized state. In this fluidized state, the solid fuel has more sufficient contact with the gas. This ensures combustion efficiency. In fluidized state, the flow rates of circulating exhaust gas, air, and fuel gas are adjusted to keep combustion in an oxygen-deficient state. Due to the oxygen-deficient combustion and the heat carried away by the circulating exhaust gas, the combustion temperature is reduced, which helps to reduce the generation of nitrogen during high-temperature combustion. At the same time, the flue gas produced by combustion (solid fuel is cracked and produces flue gas) is spiral after passing through the air outlet 252. This effectively prevents a large amount of dust from accumulating above the windshield. Meanwhile, the air sprayed from the atomizing nozzle 234 can effectively prevent the atomizing nozzle 234 from being blocked by flue gas. The generated flue gas is led out through the air outlet 211. The slag produced in the process is cleaned through the slag discharge port 121 on the end cap 12. The slag discharge port 121 is connected to the bottom of the combustion chamber 21.

[0045] For the combustion of liquid materials, the liquid material enters through the inlet pipe 231, is buffered in the liquid distribution chamber 23, and then sprayed out through the atomizing nozzle 234. The atomizing nozzle 234 enables the liquid to be sprayed out in a mist, thus ensuring more complete contact with air and guaranteeing combustion effect. During this process, the air drawn in by the venturi tube B232 mixes with the fuel oil, making the fuel oil atomized more evenly. The preheated air and the circulating exhaust gas also enter from the bottom of the burner 2, pass through the air distribution plate 24, and then spirally flow out through the air outlet 252. The liquid material is in full contact with the windshield 25 above. During the contact process, the liquid fuel is in the form of a mist, while the air and circulating exhaust gas flow in a spiral shape, so the gas and liquid are mixed more evenly, achieving complete combustion of the liquid material. At this time, by controlling the air intake, the combustion is also in an oxygen-deficient state, and the circulating exhaust gas carries away some heat, controlling the combustion temperature and suppressing the generation of nitrogen in high-temperature combustion. The combustion of the liquid mainly takes place in the chamber above the windshield 25, and the hot air generated by the combustion is led out through the air outlet pipe 211.

[0046] In summary, this invention can be used for combustion of different types of fuels, and achieves good combustion results. The hot air and flue gas generated by combustion are led into the combustion chamber 42 through the exhaust pipe 211. Before entering the combustion chamber 42, the hot air is distributed through the air distribution chamber 413. The air distribution holes 414 on the air distribution chamber 413 ensure that the hot air flows into the combustion chamber 42 in a more dispersed and even manner. In the combustion chamber 42, on the one hand, the cold air is preheated by heat exchange with the wall of the chamber, which helps to stabilize combustion. On the other hand, the preheated air is injected into the combustion chamber 42 through the air inlet 421 and the jet pipe 422, thereby achieving more complete combustion of the hot air. During this process, the direction of the air is opposite to the direction of the hot air generated by combustion, which prolongs the contact time and makes the mixing more uniform and the combustion more complete. Secondary combustion, through staged combustion, reduces the heat in the combustion chamber 42, thereby suppressing the generation of nitrogen from high-temperature combustion and achieving low-NOx combustion and emissions. During the process, the preheated air enters the air duct 3 through the vent 411 and then goes to the burner 2. The flow display controller 31 on the air duct 3 is used to display and control the air flow. At the same time, it will be easy for those skilled in the art to understand that flow display controllers are arranged on the pipes connected to the air inlet 431, the liquid inlet pipe 231, the air inlet pipe, and the circulating air duct for displaying and controlling the flow, thereby achieving a reasonable distribution of air volume, circulating exhaust gas volume, and fuel volume, which can achieve low-NOx combustion and ensure the stable operation of the process. At the same time, the addition of solid fuel is controlled by a rotary valve to ensure that the amount of solid fuel is added appropriately.

[0047] Application Example 1

[0048] A chemical plant used the hot air furnace of this invention during its low-NOx transformation process. After the transformation was completed, it adopted a fuel usage method that mainly used oil fuel and supplemented by biomass pellets.

[0049] During long-term operation, it was found that the fuel (oil fuel) and biomass pellets could be switched at will, and the equipment operated stably without any clogging of the atomizing nozzles.

[0050] Especially during the summer when biomass pellets are relatively cheap, the hot air furnace continuously operates on biomass pellets. After the operation ends, it is switched to oil fuel. All aspects of the hot air furnace still operate well and stably, and there is no phenomenon of atomizing nozzle blockage, which ensures the stable production operation.

[0051] During long-term operation, the hot air furnace of this invention has shown stable operation and consistent thermal efficiency. Compared with the original oil-fired hot air furnace, it was found that the nitrogen oxide content in the exhaust gas was reduced to 23 mg / m³. 3 It meets the existing emission standards for nitrogen oxides among air pollutants, while reducing costs by about 5-10% compared to the past. The economic and environmental benefits are quite significant.

[0052] Application Example 2

[0053] The hot air furnace of this invention is used for winter heating in a greenhouse. During use, the fuel is mainly biomass fuel. This biomass fuel is different from ordinary biomass pellets on the market. It is made from crushed straw, corn cobs and other common materials in daily life.

[0054] During operation, the hot air furnace of this invention operated stably with consistent thermal efficiency, ensuring the normal growth of vegetables and fruits. Simultaneously, the biomass raw material consumption during operation was essentially equivalent to summer storage, achieving near-zero input for combustion. Technical personnel measured nitrogen oxide emissions at approximately 25 mg / m³. 3 It fully meets environmental protection requirements and conforms to the concept of green and environmentally friendly development.

[0055] Application Example 3

[0056] A steel plant implemented environmental protection renovations. Before the renovation, it used a gas-fired hot blast stove, but after the renovation, it used the hot blast stove of this invention.

[0057] In using the hot blast stove of this invention, the steel plant still retains the original gas combustion method, and adds an appropriate amount of biomass raw materials to the hot blast stove while the gas is burning, realizing a heating method in which gas and biomass pellets work synergistically.

[0058] During long-term operation, the hot air furnace of this invention has demonstrated stable operation and consistent thermal efficiency. Compared with the original gas-fired hot air furnace, it was found that gas consumption was reduced by approximately 20%, while costs were also reduced by approximately 10%, and the nitrogen oxide content in the exhaust gas was reduced to 25 mg / m³. 3 The economic and environmental benefits are quite significant.

[0059] It can be seen that by using the hot air furnace of this invention, not only can multiple types of fuel be used, but different types of fuel can also be mixed during the process, which makes the combustion of the hot air furnace more stable. In the process of use, combined with the relatively environmentally friendly and economical biomass pellets, the production cost can be effectively reduced while ensuring the performance of the hot air furnace. Both the economic and environmental benefits are quite obvious, which meets the requirements of environmental protection and the development of the times.

[0060] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A multi-type fuel low-NOx combustion hot air stove, comprising a shell (1) and a support (11) disposed below the shell (1), characterized in that: The housing (1) is provided with a burner (2) and a hot air chamber (4). The burner (2) is a solid-liquid-gas three-in-one burner. An air inlet pipe (221) is provided at the bottom of the burner (2), and an air outlet pipe (211) is provided above the burner (2). The air outlet pipe (211) is connected to the hot air chamber (4). The burner (2) is provided with a combustion chamber (21), and a mixing chamber (22) is provided below the combustion chamber (21). The mixing chamber (22) is inverted cone shape. The air inlet pipe (221) is located at the bottom of the mixing chamber (22). An air inlet pipe (222) and a circulating air pipe (223) are provided on the side wall of the mixing chamber (22). The air inlet pipe (222) transports gaseous fuel, and the circulating air pipe (223) transports circulating exhaust gas. The inlet of the circulating air duct (223) is tangent to the wall of the mixing chamber (22), and the air intake pipe (222) and the circulating air duct (223) are respectively arranged on both sides of the mixing chamber (22). A wind deflector (25) is provided in the combustion chamber (21). The wind deflector (25) is conical. An air outlet (252) is provided above the wind deflector (25). The air outlet pipe (211) is located on the wall of the combustion chamber (21) above the wind deflector (25). The wind shield (25) divides the combustion chamber (21) into upper and lower parts. The lower part is used for the combustion of solid fuel, and the upper part is used for the combustion of liquid fuel. The entire combustion chamber (21) is used for the combustion of gaseous fuel. A liquid distribution chamber (23) is provided above the combustion chamber (21). The liquid distribution chamber (23) is connected to the liquid inlet pipe (231) above. The liquid inlet pipe (231) transports liquid fuel. An atomizing nozzle (234) is installed below the liquid distribution chamber (23). A cyclone plate (253) is arranged around the inner periphery of the air outlet (252). A feed pipe (212) is provided above the combustion chamber (21). The feed pipe (212) transports solid fuel. The feed pipe (212) passes through the liquid distribution chamber (23) but is not connected to the liquid distribution chamber (23). The outlet of the feed pipe (212) extends to the lower part of the air outlet (252). A slag discharge channel is provided at the bottom of the combustion chamber (21). Venturi tubes A (224) are respectively installed in the air inlet pipe (222) and the circulating air pipe (223). Venturi tubes A (224) are connected to the air inlet pipe (221) through the suction pipe A (225). Venturi tubes B (232) are installed on the liquid inlet pipe (231). Venturi tubes B (232) are connected to the air inlet pipe (221) through the suction pipe B (233).

2. The multi-fuel low-NOx combustion hot blast stove according to claim 1, characterized in that: An air distribution plate (24) is provided between the combustion chamber (21) and the mixing chamber (22), and an air cap (241) is arranged on the air distribution plate (24).

3. The multi-type fuel low-NOx combustion hot blast stove according to claim 1, characterized in that: A baffle (41) is provided in the hot air cavity (4), and an air distribution cavity (413) is provided in the baffle (41). The air outlet pipe (211) is connected to one side of the air distribution cavity (413), and the other side of the air distribution cavity (413) is connected to the combustion chamber (42). An air distribution hole (414) is arranged on the side plate between the air distribution cavity (413) and the combustion chamber (42). A heat exchange air cavity (43) is formed between the combustion chamber (42) and the shell (1). An air inlet (431) is provided at one end of the heat exchange air cavity (43), and the other end of the heat exchange air cavity (43) is connected to the combustion chamber (42) through the air inlet hole (421). The combustion chamber (42) and the heat exchange air cavity (43) exchange heat in opposite directions.

4. The multi-type fuel low-NOx combustion hot blast stove according to claim 3, characterized in that: The heat exchange air cavity (43) is provided with a spiral baffle (432).

5. The multi-type fuel low-NOx combustion hot blast stove according to claim 3, characterized in that: The air inlet (421) is connected to the jet pipe (422), and the jet pipe (422) is arranged at an angle toward the direction of air outlet of the air distribution chamber (413).

6. The multi-type fuel low-NOx combustion hot blast stove according to claim 3, characterized in that: The heat exchange air chamber (43) is provided with a vent (411) on the baffle (41). The vent (411) is connected to the air duct (3). The air duct (3) is connected to the air inlet pipe (221). A flow display controller (31) is installed on the air duct (3).

Images