Direct combustion incinerator with ultra-low NOx emissions

Abstract

A direct combustion incinerator with ultra-low nitrogen oxide emission, a VOCs front wall nozzle is arranged at the front end of the incinerator body, a furnace front nozzle is arranged at intervals on the front outer wall of the incinerator body, and an incinerator exhaust chamber is installed, a VOCs air inlet pipe is arranged on the front end surface of the incinerator exhaust chamber, the entire incinerator is wrapped with a combustion-supporting air chamber, a combustion-supporting air inlet pipe is arranged on the combustion-supporting air chamber, and a VOCs circumferential nozzle, a cooling medium nozzle, a shallow oxidation zone nozzle and a deep oxidation zone nozzle arranged in an annular manner are arranged on the incinerator body in sequence, the entire furnace is divided into a reduction zone, a cooling zone, a shallow oxidation zone and a deep oxidation zone, the start-up burner is connected to the furnace, the exhaust gas pipeline is connected to the exhaust gas chamber, and the exhaust gas enters the furnace through the nozzle and the nozzle for combustion. The air inlet is connected to the wind chamber, and the combustion-supporting air is sprayed into the furnace through the nozzle to provide the required air volume for the exhaust gas combustion and ensure the burnout rate. The incinerator is equipped with a cooling medium nozzle for spraying a cooling agent to maintain the temperature field in the furnace within the operating temperature range.

Description

Technical Field

[0001] The invention relates to a direct combustion incinerator, in particular to a direct combustion incinerator with ultra-low nitrogen oxide emission suitable for treating organic waste gas with high calorific value and complex components. Background Art

[0002] Volatile organic compounds (VOCs), as the main branch of organic compounds, refer to organic compounds with a saturated vapor pressure greater than 70Pa at room temperature and a boiling point within 260°C at normal pressure. VOCs cause serious pollution, reacting with NOx and CnHm in the presence of sunlight, absorbing infrared radiation from the ground surface and causing the greenhouse effect; they destroy the ozone layer to form an ozone hole, causing human cancer and animal and plant poisoning.

[0003] At present, there are two main methods for treating VOCs and organic waste gas in China: one is the recovery method, and the other is the elimination method. Among them, the elimination method includes direct incineration, regenerative combustion, catalytic combustion, biological oxidation and integrated technology. Direct incineration is the most effective treatment method for high calorific value VOCs, but due to the high calorific value of VOCs, the reaction temperature in the incinerator is also relatively high, resulting in a large amount of NOx. The existing incinerator structure mostly uses a start-up burner to ignite VOCs, and is equipped with sufficient combustion-supporting air. The entire mixing process is completed at the front end of the incinerator. Secondary pollutants will be generated during the treatment process. If they are directly discharged, they will pollute the environment; if back-end treatment is performed, the initial investment and operating costs of the equipment will increase. Summary of the invention

[0004] Technical problem: The purpose of the present invention is to overcome the problems existing in the prior art and provide a direct combustion incinerator with ultra-low nitrogen oxide emissions that is simple in structure, easy to operate, reduces costs, and can avoid secondary environmental pollution.

[0005] Technical solution: The present invention is a direct combustion incinerator with ultra-low nitrogen oxide emissions, comprising a starting burner and an incinerator body composed of a refractory heat-insulating material layer, wherein the starting burner is arranged at the center of the front panel of the incinerator body, and the incinerator body around the starting burner is provided with a plurality of VOCs front wall nozzles connected to the furnace, and a plurality of furnace front nozzles connected to the furnace are arranged at intervals on the front outer wall of the incinerator body, an incinerator exhaust chamber is mounted on the front of the incinerator body, and a plurality of VOCs air inlet pipes connected to the incinerator exhaust chamber are arranged on the front end surface of the incinerator exhaust chamber, the entire incinerator exhaust chamber and the outside of the incinerator body are wrapped with a combustion-supporting air chamber, and the combustion-supporting air chamber is provided with a combustion-supporting air inlet pipe connected to the furnace front nozzle, and the incinerator body is provided with VOCs circumferential nozzles arranged in a ring shape and at intervals, The cooling medium nozzle, the shallow oxidation zone nozzle and the deep oxidation zone nozzle divide the entire furnace into a reduction zone, a cooling zone, a shallow oxidation zone and a deep oxidation zone, wherein the cooling medium nozzle (9) is connected to a cooling medium supply pipe; the shallow oxidation zone nozzle is arranged axially inclined, and the injection angle is α with respect to the radial direction; the deep oxidation zone nozzle is arranged radially inclined, and the injection angle is β with respect to the radial direction; during operation, different types of VOCs are mixed in the exhaust chamber through multiple VOCs air intake pipes, and then sprayed into the furnace through the incinerator front wall nozzle and the circumferential nozzle, and burn in the reduction zone, cooling zone, shallow oxidation zone and deep oxidation zone in the furnace in turn; during the combustion process, the combustion air enters the furnace at two different angles through the shallow oxidation zone nozzle and the deep oxidation zone nozzle, and the position and time of the combustion air injection are controlled.

[0006] The flow ratio between the front wall nozzle and the circumferential nozzle is between 1:4 and 1:1, and the exhaust gas flow rates in the front wall nozzle and the circumferential nozzle are controlled between 10 and 30 m / s.

[0007] The distance L2 between the circumferential nozzle and the front end surface of the incinerator is 0.5-1.5m.

[0008] The jet angle of the shallow oxidation zone nozzle and the radial angle α are between 15 and 75 degrees.

[0009] The jet angle of the deep oxidation zone nozzle and the radial angle β are between 0 and 60 degrees.

[0010] The distance between the deep oxidation zone nozzle and the furnace outlet is 1.5 to 4.5 m.

[0011] The distance between the nozzle of the shallow oxidation zone and the nozzle of the deep oxidation zone is 0.5-1.5m.

[0012] The distance between the cooling medium nozzle and the circumferential nozzle is 0.3-1.5m.

[0013] Beneficial effects: Due to the adoption of the above technical scheme, the present invention utilizes the entire incinerator furnace space to achieve the staged combustion of fuel (VOCs) during the combustion process and the staged configuration of combustion-supporting air. The staged combustion of fuel (VOCs) can prevent the concentrated combustion of fuel (VOCs) to form a local high-temperature zone, which will produce a large amount of thermal nitrogen oxides; the staged configuration of combustion-supporting air forms a reducing atmosphere by less air distribution in the early stage, and reduces the nitrogen oxides generated in the early stage to N2, thereby reducing the emission of nitrogen oxides from the incinerator. By controlling the position and time of the combustion-supporting air entering the furnace, from the front of the furnace to the tail of the furnace, a reduction zone, a shallow oxidation zone, and a deep oxidation zone of combustion are formed, which can control the generation of some fuel-type nitrogen oxides, and prolong the reaction time of VOCs, so that the temperature field in the furnace is more uniform, the high-temperature zone in the center of the flame is eliminated, and the generation of thermal nitrogen oxides is further reduced. In the early stage of combustion, a cooling zone is also set up, which is specifically for ultra-high calorific value VOCs, and a cooling medium is sprayed into the furnace to reduce the temperature of the center of the flame, thereby reducing the generation of nitrogen oxides. The invention has the advantages of simple structure, convenient operation, low cost, and avoidance of secondary environmental pollution, and has wide practicability in the technical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the present invention;

[0015] Figure 2 yes Figure 1 Schematic diagram of the nozzle arrangement in the medium-depth oxidation zone.

[0016] In the figure: 1-starting burner, 2-incinerator body, 3-combustion-supporting air chamber, 4-incinerator exhaust chamber, 5-combustion-supporting air inlet pipe, 6-VOCs air inlet pipe, 7-VOCs front wall nozzle, 8-VOCs circumferential nozzle, 9-cooling medium nozzle, 10-shallow oxidation zone nozzle, 11-deep oxidation zone nozzle, 12-refractory insulation material layer, 13-furnace, 14-furnace front nozzle. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the embodiments in the accompanying drawings:

[0018] like Figure 1As shown, a direct combustion incinerator with ultra-low nitrogen oxide emission of the present invention is mainly composed of a start-up burner 1, an incinerator body 2, a combustion-supporting air chamber 3, an incinerator exhaust chamber 4, a combustion-supporting air inlet pipe 5, a VOCs air inlet pipe 6, a VOCs front wall nozzle 7, a VOCs circumferential nozzle 8, a cooling medium nozzle 9, a shallow oxidation zone nozzle 10, a deep oxidation zone nozzle 11, a refractory insulation material layer 12, a furnace 13 and a furnace front nozzle 14. The incinerator body is composed of a refractory insulation material layer 12, the start-up burner 1 is arranged at the center of the front panel of the incinerator body, and a plurality of VOCs front wall nozzles 7 connected to the furnace 13 are arranged on the incinerator body around the start-up burner 1, and the flow ratio between the front wall nozzle 7 and the circumferential nozzle 8 is between 1:4 and 1:1, and the exhaust gas flow rate in the front wall nozzle 7 and the circumferential nozzle 8 is controlled between 10 and 30 m / s. The front outer wall of the incinerator body 2 is provided with a plurality of furnace front nozzles 14 connected to the furnace 13 at intervals, the front part of the incinerator body is provided with an incinerator exhaust chamber 4, the front end surface of the incinerator exhaust chamber 4 is provided with a plurality of VOCs air inlet pipes 6 connected to the incinerator exhaust chamber, the entire incinerator exhaust chamber 4 and the outside of the incinerator body are wrapped with a combustion-supporting air chamber 3, the combustion-supporting air chamber 3 is provided with a combustion-supporting air inlet pipe 5 connected to the furnace front nozzle 14, the incinerator body is provided with a VOCs circumferential nozzle 8, a cooling medium nozzle 9, a shallow oxidation zone nozzle 10 and a deep oxidation zone nozzle 11 arranged in an annular manner in sequence, wherein the cooling medium nozzle 9 is provided with a VOCs circumferential nozzle 8, a cooling medium nozzle 9, a shallow oxidation zone nozzle 10 and a deep oxidation zone nozzle 11, wherein the cooling medium nozzle 9 is provided with a VOCs circumferential nozzle 8, ... The medium nozzle 9 is connected to the cooling medium supply pipe; the distance between the cooling medium nozzle 9 and the circumferential nozzle 8 is 0.3 to 1.5 m; the distance L2 between the circumferential nozzle 8 and the front end face of the incinerator is 0.5 to 1.5 m; the injection angle of the shallow oxidation zone nozzle 10 and the radial angle α are between 15 and 75°; the injection angle of the deep oxidation zone nozzle 11 and the radial angle β are between 0 and 60°; the distance between the deep oxidation zone nozzle 11 and the furnace outlet end face is 1.5 to 4.5 m; the distance between the shallow oxidation zone nozzle 10 and the deep oxidation zone nozzle 11 is 0.5 to 1.5 m. The entire furnace 13 is divided into a reduction zone L1, a cooling zone L3, a shallow oxidation zone L4 and a deep oxidation zone L5. The shallow oxidation zone nozzle 10 is tilted along the axial direction, and the injection angle is α with respect to the radial direction. The deep oxidation zone nozzle 11 is tilted along the radial direction, and the injection angle is β with respect to the radial direction. During operation, different types of VOCs are mixed in the exhaust chamber 4 through multiple VOCs air inlet pipes 6, and then sprayed into the furnace 13 through the incinerator front wall nozzle 7 and the circumferential nozzle 8. They are burned in stages in the reduction zone L1, the cooling zone L3, the shallow oxidation zone L4 and the deep oxidation zone L5 in the furnace 13 in turn. During the combustion process, the combustion-supporting air enters the furnace 13 at two different angles through the shallow oxidation zone nozzle 10 and the deep oxidation zone nozzle 11, and the position and time of the combustion-supporting air injection are controlled.

[0019] The combustion-supporting air entering the combustion-supporting air chamber 3 from the combustion-supporting air inlet pipe 5 is divided into three parts. The air intake from the nozzle 14 at the front of the furnace accounts for 40-80% of the total air volume, the air intake from the nozzle 10 in the shallow oxidation zone accounts for 10-30% of the total air volume, and the air intake from the nozzle 11 in the deep oxidation zone accounts for 10-30% of the total air volume.

[0020] Working principle: the start-up burner 1 is installed on the front panel of the incinerator, and the VOCs front wall nozzle 7 is arranged around it to provide a stable heat source in the initial operation of the incinerator, ignite the VOCs nozzle (7) around the burner, form a larger heat source, ignite the VOCs circumferential nozzle 8, and ensure the normal combustion of VOCs; the combustion-supporting air enters the combustion-supporting air chamber 3 through the combustion-supporting air inlet pipe 5, and then enters the furnace 13 through three different positions: the front nozzle 14, the shallow oxidation zone nozzle 10 and the deep oxidation zone nozzle 11. The amount of air injected into the furnace front nozzle 14 provides the combustion requirements of most VOCs. The main components of the flue gas after combustion are CO2, CO, H2O and NOx. A part of the NOx generated by combustion is reduced to N2 by CO or free C in organic matter; the air injected into the shallow oxidation zone nozzle 10 provides the oxidation requirements of part of CO, and the whole state is still in an oxygen-deficient reducing atmosphere to further reduce NOx; finally, excessive air is injected into the deep oxidation zone nozzle 11 to ensure the burnout rate of VOCs. For high calorific value VOCs, a cooling zone is set up in the incinerator to cool the furnace through the cooling medium nozzle 9. The incinerator uses refractory insulation materials to make an insulated furnace to reduce heat loss; and the combustion-supporting air chamber 3 is used to cool the inner and outer walls of the incinerator to ensure that the outer wall of the incinerator does not overheat.

Claims

1. A direct combustion incinerator with ultra-low nitrogen oxide emissions, comprising a start-up burner (1) and an incinerator body composed of a refractory insulation material layer (12), characterized in that: The start-up burner (1) is arranged at the center of the front panel of the incinerator body, and a plurality of VOCs front wall nozzles (7) connected to the furnace (13) are arranged on the incinerator body around the start-up burner (1). A plurality of furnace front nozzles (14) connected to the furnace (13) are arranged at intervals on the front outer wall of the incinerator body (2). The front part of the incinerator body is provided with an incinerator exhaust chamber (4), and a plurality of VOCs air inlet pipes (6) connected to the incinerator exhaust chamber are arranged on the front end surface of the incinerator exhaust chamber (4). The entire incinerator exhaust chamber (4) and the outside of the incinerator body are wrapped with a combustion-supporting air chamber (3), and the combustion-supporting air chamber (3) is provided with A combustion air inlet pipe (5) is connected to the nozzle (14) at the front of the furnace. The incinerator body is provided with a VOCs circumferential nozzle (8), a cooling medium nozzle (9), a shallow oxidation zone nozzle (10) and a deep oxidation zone nozzle (11) arranged in a ring shape and spaced apart in sequence, so that the entire furnace (13) is divided into a reduction zone (L1), a cooling zone (L3), a shallow oxidation zone (L4) and a deep oxidation zone (L5), wherein the cooling medium nozzle (9) is connected to the cooling medium supply pipe; the shallow oxidation zone nozzle (10) is arranged to be inclined along the axial direction, and the angle between the injection angle and the radial direction is α; the deep oxidation zone nozzle (11) is arranged to be inclined along the radial direction, and the injection angle is The angle between the VOCs and the radial direction is β; when working, different types of VOCs are introduced into the exhaust gas chamber (4) of the incinerator through multiple VOCs air inlet pipes (6) and mixed, and then sprayed into the furnace (13) through the VOCs front wall nozzle (7) and the VOCs circumferential nozzle (8), and are burned in stages in the reduction zone (L1), cooling zone (L3), shallow oxidation zone (L4) and deep oxidation zone (L5) in the furnace (13). During the combustion process, the combustion air enters the furnace (13) at two different angles through the shallow oxidation zone nozzle (10) and the deep oxidation zone nozzle (11), and the position and time of the combustion air injection are controlled; The distance between the VOCs circumferential nozzle (8) and the front end face of the incinerator is 0.5~1.5m; the injection angle of the shallow oxidation zone nozzle (10) and the radial angle α are between 15~75°; the injection angle of the deep oxidation zone nozzle (11) and the radial angle β are between 0~60°; the distance between the deep oxidation zone nozzle (11) and the furnace outlet is 1.5~4.5m; the distance L2 between the shallow oxidation zone nozzle (10) and the deep oxidation zone nozzle (11) is 0.5~1.5m; the distance between the cooling medium nozzle (9) and the VOCs circumferential nozzle (8) is 0.3~1.5m.

2. The direct combustion incinerator with ultra-low nitrogen oxide emissions according to claim 1, characterized in that: The flow ratio between the front wall nozzle (7) and the circumferential nozzle (8) is between 1:4 and 1:1, and the exhaust gas flow rates in the front wall nozzle (7) and the circumferential nozzle (8) are controlled between 10 and 30 m / s.

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