Low-nitrogen combustion chamber system of coal-fired kiln

Abstract

The utility model discloses a coal-fired kiln low-nitrogen combustion chamber system which comprises a coal-fired kiln body, four pulverized coal spray pipes and a combustion chamber inner spouting reactor, a refractory material layer is arranged on the inner wall of the coal-fired kiln body, a set of combustion chamber inner spouting reactor is arranged in the top of the coal-fired kiln body in a surrounding mode, and the pulverized coal spray pipes are arranged in the top of the coal-fired kiln body. The pulverized coal spraying pipes are arranged at the bottom of the coal-fired kiln body in a surrounding mode, one ends of the pulverized coal spraying pipes penetrate through the wall of the coal-fired kiln body from outside to inside and exceed the refractory material layer by 10 mm, the other ends of the pulverized coal spraying pipes are communicated with a pulverized coal supply pipeline through a pulverized coal distributor, and valves are arranged on the pulverized coal spraying pipes. On the basis of an existing industrial coal-fired kiln, the combustion position of pulverized coal is optimized by changing the spouting reactor and the pulverized coal spray pipe in the combustion chamber, the effect of reducing NOX emission is achieved through the combustion characteristic of the pulverized coal, and the industrial coal-fired kiln has the advantages of being reliable in process, low in cost and the like.

Description

Technical field:

[0001] The utility model relates to the technical field of environmental protection, in particular to a low-nitrogen combustion chamber system of a coal-fired kiln. Background technology:

[0002] Industrial kilns play an important role in my country's industrial production. There are countless industrial kilns of various specifications in China, of which coal-fired kilns account for more than 80%. The structure, heating process, temperature control and atmosphere in the kiln of industrial kilns will directly affect the quality of processed products. The difficulty of treating the flue gas of industrial kilns is increasing. Some coal-fired kilns with outdated designs and backward technologies will gradually be eliminated. There is an urgent need for a green and environmentally friendly industrial kiln to replace them. Utility model content:

[0003] The technical problem to be solved by the utility model is that the thermal nitrogen oxides and fuel nitrogen oxides generated when coal powder is burned in the combustion chamber of the existing coal-fired kiln are high.

[0004] In order to solve the above technical problems, the utility model provides a technical solution: a low-nitrogen combustion chamber system of a coal-fired kiln, comprising a coal-fired kiln body, a coal powder nozzle and a gas-spurting reactor in the combustion chamber, characterized in that: a refractory material layer is arranged on the inner wall of the coal-fired kiln body, a set of the gas-spurting reactor in the combustion chamber is arranged around the top of the coal-fired kiln body, there are four coal powder nozzles, which are evenly arranged around the bottom of the coal-fired kiln body, and a low-nitrogen combustion chamber is formed between the gas-spurting reactor and the coal powder nozzle in the combustion chamber, one end of the coal powder nozzle penetrates the wall of the coal-fired kiln body from the outside to the inside and exceeds the refractory material layer by 10 mm, the other end of the coal powder nozzle is connected to the coal powder supply pipeline through a coal powder distributor, and a valve is arranged on the coal powder nozzle.

[0005] Furthermore, six air cannons are arranged at the lower part of the jet reactor in the combustion chamber, and the six air cannons are evenly arranged around and aimed at the shrinkage step of the jet reactor in the combustion chamber.

[0006] Furthermore, four artificial cleaning holes are evenly arranged on the coal-fired kiln body between the air cannon and the coal powder nozzle.

[0007] Furthermore, the refractory material layer is constructed by using high-alumina refractory bricks or explosion-proof castables and calcium silicate boards or nano thermal insulation boards.

[0008] Furthermore, the pulverized coal nozzle is made of a heat-resistant material.

[0009] The beneficial effects of the utility model are:

[0010] 1. Based on the industrial coal-fired kiln, the present application utilizes the combustion characteristics of the original industrial coal-fired kiln and coal powder through new construction and technical transformation, and changes the combustion position and combustion space of the coal powder by adding a spray reactor 3 and a coal powder nozzle 2 in the combustion chamber. On the basis of the original denitrification reaction area, a low-nitrogen combustion chamber for denitrification reaction is formed in the main body of the coal-fired kiln. The CO, CN, CH4, H2, HCN and fixed carbon generated by the combustion of the injected coal powder are used as denitrification reducing agents. There is no need to add a denitrification catalyst, and a large amount of NOX generated in the kiln is reduced to N2, so as to achieve the purpose of reducing nitrogen oxide emissions.

[0011] 2. In this application, the pulverized coal injected through four pulverized coal nozzles at the bottom of the coal-fired kiln body is burned in an oxygen-deficient or oxygen-deficient state to generate a large amount of CO to reduce the NOX generated by the combustion, thereby reducing the NOX generated during the fuel combustion process. The denitrification efficiency of the low-nitrogen combustion chamber is adjusted by changing the time of the reduction reaction to achieve different NOX emission indicators.

[0012] 3. The setting of the cleaning holes and air cannon in this application can regularly clean the inner wall of the combustion chamber to prevent the incompletely burned coal powder from forming a crust on the inner wall of the combustion chamber, thereby changing the reaction space and causing a decrease in combustion effect.

[0013] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. Description of the drawings:

[0014] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only one of the drawings in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 This is a schematic diagram of the structure of this application.

[0016] In the figure, 1-coal-fired kiln body, 2-coal powder nozzle, 3-spraying reactor in combustion chamber, 4-refractory material layer, 5-air cannon, 6-cleaning hole, 7-low nitrogen combustion chamber. Specific implementation method:

[0017] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0018] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.

[0019] The names of the messages or information exchanged between multiple devices in the implementation manner of the present utility model are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0020] Embodiment 1

[0021] like Figure 1 As shown, a low-nitrogen combustion chamber system of a coal-fired kiln comprises a coal-fired kiln body 1, a pulverized coal nozzle 2 and a sparging reactor 3 in the combustion chamber. A refractory material layer 4 is provided on the inner wall of the coal-fired kiln body 1. A set of sparging reactors 3 in the combustion chamber are arranged around the top of the coal-fired kiln body 1. There are four pulverized coal nozzles 2, which are evenly arranged around the bottom of the coal-fired kiln body 1. A low-nitrogen combustion chamber 7 is formed between the sparging reactor 3 in the combustion chamber and the pulverized coal nozzle 2. One end of the pulverized coal nozzle 2 penetrates the wall of the coal-fired kiln body 1 from the outside to the inside and exceeds the refractory material layer by 410 mm. The other end of the pulverized coal nozzle 2 is connected to the pulverized coal supply pipeline through a pulverized coal distributor, and a valve is provided on the pulverized coal nozzle 2.

[0022] By utilizing the combustion characteristics of the original industrial coal-fired kiln and coal powder, by adding a jet reactor 3 and a coal powder nozzle 2 in the combustion chamber, changing the combustion position and combustion space of the coal powder, a low-nitrogen combustion chamber 7 for denitrification reaction is formed in the coal-fired kiln body to achieve the purpose of reducing nitrogen oxide emissions.

[0023] The purpose of the spray reactor 3 in the combustion chamber is to change the wind speed in the combustion chamber, make the coal powder and air mix more evenly, and reduce the oxygen content in the low-nitrogen combustion chamber 7. The setting of the valve on the coal powder nozzle 2 can be calculated according to the actual working conditions and the quality of the coal powder, and the coal powder injection amount can be adjusted to ensure that the coal powder combustion time and the nitrogen oxide reduction reaction time in the low-nitrogen combustion chamber 7 are not less than 1 second. The combustion characteristics of the coal powder itself are used to achieve the effect of reducing NOX emissions, and it has the advantages of reliable process and low cost.

[0024] There is no need to add denitrification catalyst in the low-nitrogen combustion chamber. It mainly uses CO, CN, CH4, H2, HCN and fixed carbon generated by the combustion of injected coal powder as denitrification reducing agents (the concentration of reducing atmosphere in the combustion chamber is adjusted by adjusting the air supply and coal supply. The air volume is controlled by the high-temperature variable frequency induced draft fan and the coal powder is controlled by the coal supply system) to reduce the large amount of NOX generated in the kiln into N2.

[0025] The design principle is: the combustion air and fuel used in the combustion chamber are distributed to this area according to certain requirements and proportions, so that a reducing atmosphere area is generated during combustion, so as to produce reducing agents such as CO, CN, CH4, H2, HCN and fixed carbon. These reducing agents react with NOX in the flue gas and reduce NOX to non-polluting inert gases such as N2. In addition, the combustion of pulverized coal under low air excess coefficient conditions also inhibits the generation of its own fuel-type NOX, thereby achieving NOX emission reduction in the cement production process. Its main reactions are as follows:

[0026] 2CO+2NO→N2+2CO2

[0027] 2H2+2NO→N2+2H2O

[0028] 2NH i+2NO→N2+...

[0029] Among them, the refractory material layer 4 is built with high-alumina refractory bricks or explosion-proof castables and calcium silicate boards or nano-insulation boards. The formed refractory material layer 4 is insulated to reduce its own heat loss, prevent the temperature in the combustion chamber from dissipating too quickly, and reduce the temperature in the combustion chamber, affecting the reaction efficiency and quality.

[0030] The pulverized coal nozzle 2 is made of a heat-resistant material, such as cast steel or heat-resistant steel (310S). Since the pulverized coal nozzle 2 extends into the low-nitrogen combustion chamber 7, the pulverized coal nozzle 2 is prevented from being deformed by heat.

[0031] Embodiment 2

[0032] like Figure 1As shown, this embodiment is obtained by adding technical features such as air cannon 5 on the basis of embodiment one. The remaining technical features are the same as those of embodiment one, and the similarities are not repeated here. Among them, the difference between this embodiment and embodiment one is that: six air cannons 5 are arranged at the lower part of the jet reactor 3 in the combustion chamber, and the six air cannons 5 are evenly arranged around and aimed at the shrinkage step of the jet reactor 3 in the combustion chamber.

[0033] In this embodiment, the air cannon 5 is provided to periodically purge the accumulated material at the shrinkage step to prevent the crust from affecting the reaction space of the combustion chamber and thus affecting the reaction effect.

[0034] Embodiment 3

[0035] like Figure 1 As shown, this embodiment is obtained by adding technical features such as cleaning holes 6 on the basis of embodiment 2. The remaining technical features are the same as those of embodiment 2, and the similarities are not repeated here. Among them, the difference between this embodiment and embodiment 2 is that four artificial cleaning holes 6 are evenly arranged on the coal-fired kiln body 1 between the air cannon 5 and the coal powder nozzle 2.

[0036] In this embodiment, the provision of the cleaning hole 6 facilitates the inspection of the coal pipe and the cleaning of coke at the head of the coal pipe, thereby preventing the pulverized coal nozzle 2 from being blocked.

[0037] The overall technical solution formed by the above-mentioned embodiments is used in the same way as the industrial coal-fired kiln in the prior art. The high-temperature variable frequency induced draft fan controls the air volume, the coal supply system controls the amount of coal injected, and the coal powder injected by the four coal powder nozzles 2 burns in an oxygen-deficient or oxygen-deficient state to generate a large amount of CO to reduce the NOX generated by the combustion, so as to reduce the NOX generated during the fuel combustion process. At the same time, the air cannon 5 regularly blows the accumulated material at the shrinkage step, and checks and cleans the coking at the head of the coal powder nozzle 2 through the cleaning hole 6 when the working is stopped.

[0038] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A low nitrogen combustion chamber system for a coal-fired kiln, comprising a coal-fired kiln body, a coal powder nozzle and a spray reactor in the combustion chamber, characterized in that: A refractory material layer is provided on the inner wall of the coal-fired kiln body, a set of the combustion chamber jet reactor is arranged around the top of the coal-fired kiln body, there are four pulverized coal nozzles, which are evenly arranged around the bottom of the coal-fired kiln body, and a low-nitrogen combustion chamber is formed between the jet reactor and the pulverized coal nozzle in the combustion chamber, one end of the pulverized coal nozzle penetrates the wall of the coal-fired kiln body from the outside to the inside and protrudes from the refractory material layer by 10 mm, and the other end of the pulverized coal nozzle is connected to the pulverized coal supply pipeline through a pulverized coal distributor, and a valve is provided on the pulverized coal nozzle.

2. A low nitrogen combustion chamber system for a coal-fired kiln according to claim 1, characterized in that: Six air cannons are arranged at the lower part of the jet reactor in the combustion chamber, and the six air cannons are evenly arranged around and aimed at the shrinking step of the jet reactor in the combustion chamber.

3. A low nitrogen combustion chamber system for a coal-fired kiln according to claim 2, characterized in that: Four artificial cleaning holes are evenly arranged on the coal-fired kiln body between the air cannon and the coal powder nozzle.

4. A low nitrogen combustion chamber system for a coal-fired kiln according to claim 3, characterized in that: The refractory material layer is constructed by using high-alumina refractory bricks or explosion-proof castables and calcium silicate boards or nano thermal insulation boards.

5. A low nitrogen combustion chamber system for a coal-fired kiln according to claim 4, characterized in that: The pulverized coal nozzle is made of a heat-resistant material.

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