A porous biomass gas low nitrogen burner

Abstract

This invention discloses a porous biomass low-NOx burner, comprising a central air duct and a gas passage and an auxiliary air duct arranged sequentially around the central air duct from the inside out. The outlets at the front ends of the central air duct, the gas passage, and the auxiliary air duct are flush, and the front ends of the central air duct and the gas passage are provided with several through-holes. The rear ends of the central air duct, the gas passage, and the auxiliary air duct are each provided with a corresponding inlet. This invention improves the mixing degree of gas and air by setting air holes in the gas passage and the central air duct, allowing air and gas to premix through the air holes inside the burner, thereby increasing the utilization rate of gas and air, reducing exhaust emissions, and having a simple overall structure.

Description

Technical Field

[0001] The invention belongs to the technical field of combustion equipment, and in particular relates to a porous biomass gas low-nitrogen burner. Background Art

[0002] Biomass energy is the fourth largest energy source in the world, accounting for about 14% of the world's total energy consumption. Biomass energy has a wide range of sources, high volatile matter content, low ash content, and low sulfur content. Since the amount of CO2 absorbed by the growth environment is equivalent to the amount of CO2 emitted by combustion, the net CO2 emission in the energy conversion process is close to zero, which is conducive to improving the greenhouse effect. It is of great significance to study and develop technologies for efficient utilization of biomass energy, save conventional fossil energy, and optimize the energy structure. Biomass gas is a combustible gas produced by gasification furnaces from crop straw and forestry waste. It is a way for biomass energy to develop into large-scale industrial applications. At present, biomass burners are gradually being promoted and utilized.

[0003] The burner is used to burn and heat the furnace body such as a boiler or an annealing furnace. The burner is provided with a gas pipeline and an air pipeline. The gas pipeline conveys gas, and the air pipeline conveys air. An ignition head of an ignition gun is provided at the confluence of the gas conveyed by the gas pipeline and the air pipeline. The gas is ignited by the ignition head, thereby heating the furnace body. In the existing burners, the gas pipeline and the air pipeline are mostly separated, such as a cross setting, where the intersection is the intersection of the gas pipeline outlet and the air pipeline outlet, and an ignition head of an ignition gun is further provided at the intersection. This kind of burner has a complex structure. Since the gas and air are mixed at the intersection, insufficient mixing is prone to occur, resulting in insufficient combustion of the gas, resulting in energy waste, and great safety hazards caused by insufficient combustion. Summary of the invention

[0004] The purpose of the present invention is to overcome the existing technical defects and provide a porous biomass gas low-nitrogen burner. By arranging air holes on the gas channel and the central air duct, air and gas can be pre-mixed by flowing through the air holes inside the burner, thereby improving the mixing degree of gas and air, improving the utilization rate of gas and air, thereby reducing exhaust gas emissions, and the overall structure is simple.

[0005] In order to solve the above technical problems, the present invention provides a porous biomass gas low-nitrogen burner, comprising a central air duct and a gas channel and an auxiliary air duct arranged around the central air duct from the inside to the outside, wherein the outlets at the front ends of the central air duct, the gas channel and the auxiliary air duct are flush, and a plurality of penetrating air holes are arranged around the front ends of the central air duct and the gas channel; the rear ends of the central air duct, the gas channel and the auxiliary air duct are respectively provided with inlets in a one-to-one correspondence.

[0006] Furthermore, the central air duct, the auxiliary air duct and the gas channel are all annular channels.

[0007] Furthermore, the gas channel and the auxiliary air duct have the same length, and the rear end of the central air duct protrudes from the gas channel.

[0008] Furthermore, the rear end of the central air duct is an opening.

[0009] Furthermore, an air connection pipe communicating with the auxiliary air duct is provided at the rear end periphery of the auxiliary air duct, and a gas connection pipe communicating with the auxiliary air duct and passing through the rear end periphery of the gas channel is provided.

[0010] Furthermore, the air connecting pipe and the gas connecting pipe are both oriented in the same direction or in different directions.

[0011] Furthermore, the front end of the central air duct is in the shape of a truncated cone inclined toward the center, a plurality of air holes are also provided on the inclined surfaces around the truncated cone, and a central hole is provided in the center of the front end surface of the truncated cone.

[0012] Furthermore, the front end of the gas channel is tilted outward to form a trumpet shape, and a plurality of air holes are also provided around the trumpet shape.

[0013] Furthermore, an oil leakage hole is provided at the outer periphery of the front end of the auxiliary air duct.

[0014] Furthermore, the central air duct, the gas channel and the auxiliary air duct are all provided with valves for adjusting the flow rate.

[0015] The present invention has the following beneficial effects:

[0016] The porous biomass gas low-nitrogen burner of the present invention arranges air holes at the front end of the gas channel and the central air duct which are coaxially arranged, so that air and gas can be premixed by circulating through the air holes inside the burner, thereby improving the mixing degree of gas and air, and improving the utilization rate of gas and air, thereby reducing the emission of exhaust gas, and utilizing the central air duct and the auxiliary air duct which are arranged inside and outside to simultaneously input air into the gas channel, thereby improving the premixing degree and speed between air and gas, and the overall structure is simple; and the front end of the central air duct is designed to be a truncated cone shape, which can be used to compress air and make it tilted to emit outward, so that the air in the central channel can better enter the gas channel for premixing with the gas; and the front end of the gas channel is also designed to be a trumpet shape, and the trumpet shape is used to cover part of the front end outlet of the auxiliary air duct, so as to compress the air in the auxiliary air duct and make the air tilted to emit inward, so that the air in the auxiliary channel can better enter the gas channel for premixing with the gas, and the above-mentioned structural design can better make the air and gas premixed to achieve the purpose of sufficient combustion.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, which will become obvious from the following description, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 Schematic diagram of a porous biomass gas low nitrogen burner in an embodiment;

[0020] Figure 2 It is a front view of the porous biomass gas low nitrogen burner in the embodiment;

[0021] Figure 3 It is a cross-sectional view of the porous biomass gas low nitrogen burner in the embodiment. DETAILED DESCRIPTION

[0022] In order to more fully understand the technical content of the present invention, the present invention will be further introduced and explained in conjunction with the accompanying drawings and specific embodiments below; it should be noted that if there are descriptions such as "first", "second", etc. in the text, they are used to distinguish different components, etc., and do not represent the order of precedence, nor do they limit the "first" and "second" to be different types.

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0024] Example

[0025] like Figures 1 to 3As shown, the porous biomass gas low nitrogen burner shown in this embodiment includes a central air duct 1 and two gas channels 2 and an auxiliary air duct 3 arranged in sequence around the central air duct 1 from the inside to the outside. The outlets of the front ends of the central air duct 1, the gas channel 2 and the auxiliary air duct 3 are flush, and the central air duct and the front section of the gas channel are all provided with a plurality of air holes 4 evenly distributed and penetrating therethrough, so that the front sections of the central air duct, the gas channel and the auxiliary channel are connected through the air holes for gas circulation, thereby forming a premixing zone 5 at the front end of the gas channel, and the axial lengths of the air holes in the central air duct and the gas channel are the same, so that the air inside and outside At the same time, they enter the gas channel for premixing; the rear ends of the central air duct 1, the gas channel 2 and the auxiliary air duct 3 are respectively provided with inlets for the inflow of air and gas; in the above structure, air holes are provided at the front end of the gas channel and the central air duct arranged on the same axis, so that the air and gas can be premixed through the air holes inside the burner, thereby improving the mixing degree of the gas and the air, so that the utilization rate of the gas and the air is improved, thereby reducing the emission of exhaust gas, and the central air duct and the auxiliary air duct arranged inside and outside are used to input air into the gas channel at the same time, thereby improving the premixing degree and speed between the air and the gas, and the overall structure is simple.

[0026] Specifically, the central air duct 1, the auxiliary air duct 3 and the gas channel 2 are all annular channels, and the gas channel 2 is the same length as the auxiliary air duct 3. The rear end of the central air duct 1 protrudes from the gas channel 2. The protruding part of the rear end of the central air duct is convenient for setting its entrance. In practice, the central air duct is a circular tube that penetrates front and back, that is, its rear end is open and used as its entrance, thereby simplifying the overall structure.

[0027] Specifically, the rear end periphery of the auxiliary air duct 3 is provided with an air connecting pipe 31 connected thereto, and the rear end periphery of the gas channel 2 is provided with a gas connecting pipe 21 connected thereto and passing through the auxiliary air duct 3 outwardly. The air connecting pipe 31 and the gas connecting pipe 21 are respectively used as the entrances of the auxiliary air duct and the gas channel, and are used to be connected to the external air supply duct and gas supply duct respectively.

[0028] The gas connecting pipe 21 and the air connecting pipe 31 are both facing the same direction or in opposite directions, and can also be set to any direction according to actual site conditions, which is convenient and flexible. In this embodiment, they are set in opposite directions. The settings in different directions can avoid the mutual influence of two adjacent connecting pipes and minimize the axial size (i.e., the lateral size) of the porous biomass gas low-nitrogen burner.

[0029] In this embodiment, the front end of the central air duct 1 is a truncated cone 11 inclined toward the center, and a number of evenly distributed air holes are also provided on the inclined surfaces around the truncated cone 11, and a center hole 111 is provided in the center of the front end surface of the truncated cone 11; the front end of the central air duct is designed to be a truncated cone to reduce the volume of the outlet, which can be used to compress the air and make it tilted to emit outward, so that the air in the central channel can better enter the gas channel for premixing with the gas.

[0030] In this embodiment, the front end of the gas channel 2 is tilted outward to form a trumpet shape 22, and a plurality of evenly distributed air holes 4 are also provided around the trumpet shape.

[0031] In this embodiment, an oil leakage hole 6 is provided at the bottom of the outer periphery of the front end of the auxiliary air duct 3. When the gas containing tar is used for combustion, the oil leakage hole can be used to discharge the fallen tar.

[0032] In other embodiments of the present invention, a sealing cover may be provided at the oil leakage hole, and when the burner uses natural gas for combustion, there is no need to use the oil leakage hole to discharge the tar.

[0033] In other embodiments of the present invention, connecting flanges are provided at the rear end of the central air duct, the front ends of the gas connecting pipe and the air connecting pipe to facilitate connection with external gas supply pipes and air supply pipes.

[0034] In other embodiments of the present invention, valves for adjusting the gas flow or air flow are provided on the central air duct, the gas channel and the auxiliary air duct.

[0035] In other embodiments of the present invention, the axial length of the air holes provided in both the central air duct and the gas channel is controlled to be 1 / 3 to 1 / 2 of the axial length of the gas channel to ensure that the length of the premixing zone is sufficient.

[0036] The working principle of the burner of this embodiment is as follows: the front half of the gas channel (i.e. the part at the outlet) is sandwiched by the inner and outer air channels connected to it through the air holes. The specific working modes can be divided into two types:

[0037] One is the low flow rate working mode: the air from the central air duct and the auxiliary air duct enters the gas channel through the air holes and is premixed with the gas. When the premixed gas flows out of the burner through the outlet of the gas channel, it is mixed with the air again to reach a suitable concentration and is ignited.

[0038] The second is the high-flow rate working mode: pre-mixing is carried out in the same way as the first method mentioned above, but it is directly mixed inside the burner to a suitable concentration before being sprayed out of the burner and ignited. The flow rate of gas and air in the burner needs to be controlled to be greater than the reverse combustion rate to avoid combustion inside the burner and cause safety hazards.

[0039] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A porous biomass gas low nitrogen burner, characterized in that: The invention comprises a central air duct and a gas channel and an auxiliary air duct which are arranged around the central air duct in sequence from the inside to the outside, wherein the outlets of the front ends of the central air duct, the gas channel and the auxiliary air duct are flush, and a plurality of penetrating air holes are arranged around the front ends of the central air duct and the gas channel, so that the front sections of the central air duct, the gas channel and the auxiliary channel are connected through the air holes to form a premixing zone at the front end of the gas channel, and the axial lengths of the air holes arranged in the central air duct and the gas channel are the same, and the axial lengths of the air holes arranged in the central air duct and the gas channel are controlled to be 1 / 3 to 1 / 2 of the axial length of the gas channel, so that the air inside and outside enter the gas channel at the same time for premixing; the rear ends of the central air duct, the gas channel and the auxiliary air duct are respectively provided with inlets in a one-to-one correspondence; The gas channel and the auxiliary air channel have the same length, the rear end of the central air channel protrudes from the gas channel, the rear end periphery of the auxiliary air channel is provided with an air connection pipe connected thereto, and the rear end periphery of the gas channel is provided with a gas connection pipe connected thereto and passing through the auxiliary air channel; The front end of the central air duct is in the shape of a truncated cone inclined toward the center, and a plurality of air holes are also arranged on the inclined surfaces around the truncated cone, and a central hole is arranged in the center of the front end surface of the truncated cone; The front end of the gas channel is tilted outward to form a trumpet shape, and a plurality of air holes are also arranged around the trumpet shape.

2. The porous biomass gas low nitrogen burner according to claim 1, characterized in that: The auxiliary air duct and the gas duct are both annular ducts, and the central air duct is a circular tube penetrating front and back.

3. The porous biomass gas low nitrogen burner according to claim 1, characterized in that: The rear end of the central air duct is an opening.

4. The porous biomass gas low nitrogen burner according to claim 3, characterized in that: The air connecting pipe and the gas connecting pipe are both oriented in the same direction or in opposite directions.

5. The porous biomass gas low nitrogen burner according to any one of claims 1 to 4, characterized in that: An oil leakage hole is arranged at the outer periphery of the front end of the auxiliary air duct.

6. The porous biomass gas low nitrogen burner according to claim 5, characterized in that: The central air duct, the gas channel and the auxiliary air duct are all provided with valves for adjusting the flow.

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