CN111895427A - Direct-fired incinerators with ultra-low NOx emissions - Google Patents

Abstract

The utility model provides a direct combustion of ultralow nitrogen oxide emission burns burning furnace, burn burning furnace body front end and be equipped with VOCs front wall spray tube, it is equipped with furnace anterior spout to burn at the interval on the anterior outer wall of burning furnace body, and install and burn burning furnace exhaust gas chamber, it is equipped with the intake pipe of VOCs on the preceding terminal surface of burning furnace exhaust gas chamber to burn, whole burning furnace parcel has combustion-supporting plenum, be equipped with combustion-supporting air import pipe on the combustion-supporting plenum, it is cyclic annular interval arrangement's VOCs circumference spray tube to burn to be equipped with on the burning furnace body in proper order, the coolant shower nozzle, shallow oxidation district spout and deep oxidation district spout, divide into the whole furnace reduction zone, the cooling space, shallow oxidation district and deep oxidation district, start-up combustor and furnace intercommunication. The air inlet is communicated with the air chamber, and combustion-supporting air is sprayed into the hearth through the nozzle to provide required air quantity for waste gas combustion, so that the burnout rate is ensured. The cooling medium spray nozzle for spraying temperature reducing agent is arranged in the incinerator, so that the temperature field in the hearth is maintained in the working temperature range.

Description

Direct-fired incinerators with ultra-low NOx emissions

technical field

The invention relates to a direct combustion incinerator, in particular to a direct combustion incinerator with ultra-low nitrogen oxide emission suitable for the treatment of organic waste gas with high calorific value and complex composition.

Background technique

Volatile organic compounds (VOCs), as the main branch of organic compounds, refer to organic compounds whose saturated vapor pressure is greater than 70Pa at normal temperature and whose boiling point is within 260°C at normal pressure. VOCs are seriously polluted, and photochemical reactions with NOx and CnHm occur under the action of sunlight, absorbing infrared radiation on the surface and causing the greenhouse effect; destroying the ozone layer to form an ozone hole, causing human carcinogenesis and animal and plant poisoning.

At present, there are two main methods for the treatment of VOCs in China and organic waste gas treatment methods: one is the recovery method, and the other is the elimination method. Among them, elimination methods include direct incineration, regenerative combustion, catalytic combustion, biological oxidation and integrated technology. The direct incineration method is the most effective treatment method for VOCs with high calorific value, 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 being produced. Existing incinerator structures mostly use start-up burners to ignite VOCs and provide sufficient combustion-supporting air. The entire mixing process is completed at the front end of the incinerator, and secondary pollutants will be generated during the treatment process. Pollution to the environment; if the back-end treatment is carried out, the initial investment and operating cost of the equipment will be increased.

SUMMARY OF THE INVENTION

Technical problem: The purpose of the present invention is to overcome the problems existing in the prior art, and to provide a direct combustion incinerator with simple structure, convenient operation, low cost, and ultra-low nitrogen oxide emission that can avoid secondary environmental pollution.

Technical scheme: a direct combustion incinerator with ultra-low nitrogen oxide emission of the present invention includes a start-up burner and an incinerator body composed of a refractory insulation material layer, and the start-up burner is arranged on the front panel of the incinerator body In the central position, the incinerator body around the start-up burner is provided with a plurality of VOCs front wall nozzles that communicate with the furnace, and the front outer wall of the incinerator body is provided with a plurality of furnace front nozzles that communicate with the furnace, incineration The front part of the furnace body is equipped with an incinerator exhaust gas chamber, and the front end of the incinerator exhaust gas chamber is provided with a plurality of VOCs air intake pipes that communicate with the incinerator exhaust gas chamber. The air chamber, the combustion air chamber is provided with a combustion air inlet pipe that communicates with the nozzle at the front of the furnace, and the incinerator body is sequentially provided with circularly spaced VOCs circumferential nozzles, cooling medium nozzles, shallow oxidation zone nozzles and The nozzle of the deep oxidation zone divides the whole 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 the cooling medium supply pipe; The included angle between the angle and the radial direction is α, the nozzles in the deep oxidation zone are inclined radially, and the included angle between the injection angle and the radial direction is β; during operation, different types of VOCs are introduced into the exhaust gas chamber through a plurality of VOCs intake pipes After mixing, it is sprayed into the furnace through the front wall nozzle and the circumferential nozzle of the incinerator, and it is sequentially burned in the reduction zone, cooling zone, shallow oxidation zone and deep oxidation zone in the furnace. During the combustion process, the combustion-supporting air passes through the shallow oxidation zone The zone nozzle and the deep oxidation zone nozzle enter into the furnace at two different angles to control the position and injection time of the combustion-supporting air.

The flow ratio between the front wall nozzle and the peripheral nozzle is between 1:4 and 1:1, and the flow rate of the exhaust gas in the front wall nozzle and the peripheral nozzle is controlled between 10 and 30 m/s.

The distance L2 between the circular nozzle and the front end face of the incinerator is 0.5-1.5m.

The included angle α between the jetting angle and the radial direction of the nozzle in the shallow oxidation zone is between 15° and 75°.

The spray angle and the radial included angle β of the nozzle of the deep oxidation zone are between 0° and 60°.

The distance between the nozzle of the deep oxidation zone and the outlet of the furnace is 1.5-4.5m.

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

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

Beneficial effects: due to the adoption of the above-mentioned technical scheme, the present invention utilizes the entire incinerator chamber space to realize the staged combustion of fuel (VOCs) in the combustion process, and the staged configuration of combustion-supporting air, and the staged combustion of fuel (VOCs), which can prevent fuel (VOCs) will generate a large amount of thermal nitrogen oxides after concentrated combustion to form a local high temperature area; the combustion-supporting air is configured in stages, and by reducing the air distribution in the early stage, a reducing atmosphere is formed, and the nitrogen oxides generated in the early stage are reduced to N2, and the incinerator is reduced. emissions of nitrogen oxides. By controlling the position and time of combustion-supporting air entering the furnace, from the front of the furnace to the end of the furnace, the reduction zone, shallow oxidation zone and deep oxidation zone of combustion are formed, which can control the formation of some fuel-type nitrogen oxides and prolong the reaction time of VOCs. It makes the temperature field in the furnace more uniform, eliminates the high temperature zone in the center of the flame, and further reduces the generation of thermal nitrogen oxides. In the early stage of combustion, a cooling zone is also set up, which is specially aimed at ultra-high calorific value VOCs, and sprays cooling medium into the furnace to reduce the temperature of the center of the flame, thereby reducing the production of nitrogen oxides. The structure is simple, the operation is convenient, the cost is reduced, the secondary pollution of the environment can be avoided, and the utility model has wide practicability in the technical field.

Description of drawings

Fig. 1 is the structural representation of the present invention;

FIG. 2 is a schematic diagram of the arrangement of nozzles in the deep oxidation zone in FIG. 1 .

In the picture: 1-starting burner, 2-incinerator body, 3-combustion air chamber, 4-incinerator exhaust gas chamber, 5-combustion air inlet pipe, 6-VOCs intake 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 ways

The present invention will be further described below in conjunction with the embodiments in the accompanying drawings:

As shown in Figure 1, 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 gas chamber 4, a combustion-supporting air inlet pipe 5. VOCs intake pipe 6, VOCs front wall nozzle 7, VOCs circular nozzle 8, cooling medium nozzle 9, shallow oxidation zone nozzle 10, deep oxidation zone nozzle 11, refractory insulation material layer 12, furnace 13 and the front nozzle of the furnace 14 compositions. The incinerator body is composed of a refractory insulation material layer 12, and the start-up burner 1 is arranged at the center of the front panel of the incinerator body. The wall nozzle 7, the flow ratio between the front wall nozzle 7 and the circumferential nozzle 8 is between 1:4 and 1:1, and the flow rate of the exhaust gas in the front wall nozzle 7 and the circumferential nozzle 8 is controlled at Between 10 and 30m/s. The front outer wall of the described incinerator body 2 is provided with a plurality of furnace chamber front nozzles 14 communicating with the furnace chamber 13 at intervals. There is an air intake pipe 6 for a plurality of VOCs that is communicated with the incinerator exhaust gas chamber. The entire incinerator exhaust gas chamber 4 and the outside of the incinerator body are wrapped with a combustion-supporting air chamber 3. Combustion-supporting air inlet pipe 5, the incinerator body is sequentially provided with VOCs circumferential nozzles 8, cooling medium nozzles 9, shallow oxidation zone nozzles 10 and deep oxidation zone nozzles 11 arranged in annular intervals, wherein cooling medium nozzles 9 Connect the cooling medium supply pipe; the distance between the cooling medium nozzle 9 and the circumferential nozzle 8 is 0.3-1.5m; the distance L2 between the circumferential nozzle 8 and the front end of the incinerator is 0.5-1.5m ; The injection angle and the radial angle of the nozzle 10 in the shallow oxidation zone are α between 15 and 75°; the injection angle and the radial angle β of the nozzle 11 in the deep oxidation zone are between 0 and 60°. The distance between the deep oxidation zone nozzle 11 and the furnace outlet end face is 1.5-4.5m; the distance between the shallow oxidation zone nozzle 10 and the deep oxidation zone nozzle 11 is 0.5-1.5m. 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 nozzles 10 in the shallow oxidation zone are inclined along the axial direction, and the angle between the injection angle and the radial direction is α. The nozzles 11 in the deep oxidation zone are inclined along the radial direction, and the angle between the injection angle and the radial direction is β; during operation, different types of VOCs are mixed into the exhaust gas chamber 4 through the intake pipes 6 of multiple VOCs, and then pass through the front wall of the incinerator. The nozzle 7 and the circumferential nozzle 8 are sprayed into the furnace chamber 13, and are sequentially burned in the reduction zone L1, the cooling zone L3, the shallow oxidation zone L4 and the deep oxidation zone L5 in the furnace chamber 13. During the combustion process, the combustion-supporting air passes through the shallow oxidation zone. The zone nozzle 10 and the deep oxidation zone nozzle 11 enter the air into the furnace 13 at two different angles to control the injection position and injection time of the combustion-supporting air.

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, and the air intake from the nozzle 10 in the shallow oxidation zone accounts for 10-30% of the total air volume. %, the air intake volume of the nozzle 11 in the deep oxidation zone accounts for 10-30% of the total air volume.

Working principle: Install the start-up burner 1 on the front panel of the incinerator, and arrange the VOCs front wall nozzle 7 around it to provide a stable heat source in the early stage of the incinerator's operation, and ignite the VOCs nozzle (7) around the burner to form a stable heat source. The larger heat source ignites the VOCs circular nozzle 8 to 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 passes through the front nozzle 14, the shallow oxidation area nozzle 10 and the deep oxidation area. The three different positions of the nozzle 11 in the area enter the furnace 13. The amount of air injected by the nozzle 14 at the front of the furnace provides most of the VOCs combustion needs. The main components of the burned flue gas are CO2, CO, H2O and NOx, and the NOx generated by the combustion Part of it is reduced to N2 by CO or free C in organic matter; the air injected from the nozzle 10 in the shallow oxidation zone is provided for part of CO oxidation, and the whole state is still in an oxygen-deficient reducing atmosphere to further reduce NOx; finally, it passes through the deep oxidation zone. Excess air is injected into the nozzle 11 to ensure the burnout rate of VOCs. For VOCs with high calorific value, the incinerator is provided with a cooling zone, and the furnace is cooled by the cooling medium nozzle 9. The incinerator is made of refractory insulation material to make an adiabatic furnace to reduce heat loss; The outer wall is cooled to ensure that the outer wall of the incinerator does not overheat.

Claims (8)

1. a direct combustion incinerator of ultra-low nitrogen oxide emission, comprising a start-up burner (1) and the incinerator body that is made up of a refractory insulation material layer (12), it is characterized in that: the described start-up burner (1) ) is set at the center position of the front panel of the incinerator body, the incinerator body around the starter burner (1) is provided with a plurality of VOCs front wall nozzles (7) communicating with the furnace (13), and the incinerator body ( 2) The front outer wall of the front part is provided with a plurality of furnace front nozzles (14) communicating with the furnace (13) at intervals, and the front part of the incinerator body is fitted with an incinerator waste gas chamber (4), and the incinerator waste gas chamber (4) is provided with a The front end surface is provided with a plurality of air intake pipes (6) for VOCs that communicate with the incinerator exhaust gas chamber. ) is provided with a combustion-supporting air inlet pipe (5) that communicates with the nozzle (14) at the front of the furnace, and the incinerator body is sequentially provided with VOCs circumferential nozzles (8) and cooling medium nozzles (9) arranged in annular intervals. ), shallow oxidation zone nozzle (10) and deep oxidation zone nozzle (11), divide the whole furnace (13) into reduction zone (L1), cooling zone (L3), shallow oxidation zone (L4) and 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 inclined along the axial direction, and the angle between the injection angle and the radial direction is α, and the deep oxidation zone nozzle (11) It is inclined along the radial direction, and the angle between the injection angle and the radial direction is β; during operation, different types of VOCs are mixed into the exhaust gas chamber (4) through the intake pipes (6) of multiple VOCs, and then sprayed through the front wall of the incinerator. The pipe (7) and the circumferential nozzle (8) are sprayed into the furnace chamber (13), and sequentially in the reduction zone (L1), cooling zone (L3), shallow oxidation zone (L4) and deep oxidation zone ( L5) Staged combustion. During the combustion process, the combustion-supporting air enters the furnace (13) through the shallow oxidation zone nozzle (10) and the deep oxidation zone nozzle (11) according to two different angles, and controls the position and position of the combustion-supporting air injection. Spray time. 2. the direct combustion incinerator of a kind of ultra-low nitrogen oxide emission according to claim 1, is characterized in that: the flow ratio between described front wall nozzle (7) and circumferential nozzle (8) is in Between 1:4 and 1:1, the flow rate of exhaust gas in the front wall nozzle (7) and the circumferential nozzle (8) is controlled between 10 and 30 m/s. 3. The direct combustion incinerator with ultra-low nitrogen oxide emission according to claim 1, characterized in that: the distance between the circumferential nozzle (8) and the front end of the incinerator is 0.5 to 1.5 m . 4. The direct combustion incinerator of a kind of ultra-low nitrogen oxide emission according to claim 1, characterized in that: the injection angle and the radial angle of the nozzle (10) in the shallow oxidation zone are that α is 15～15 between 75°. 5. The direct combustion incinerator with ultra-low nitrogen oxide emission according to claim 1, characterized in that: the injection angle and the radial angle β of the nozzle (11) in the deep oxidation zone are 0 to 60 ° between. 6 . The direct combustion incinerator with ultra-low nitrogen oxide emission according to claim 1 , wherein the distance between the nozzle (11) of the deep oxidation zone and the furnace outlet is 1.5 to 4.5 m. 7 . 7. The direct combustion incinerator of a kind of ultra-low nitrogen oxide emission according to claim 1, is characterized in that: the distance L2 between described shallow oxidation zone nozzle (10) and deep oxidation zone nozzle (11) 0.5 to 1.5m. 8. The direct combustion incinerator with ultra-low nitrogen oxide emission according to claim 1, characterized in that: the distance between the cooling medium nozzle (9) and the circumferential nozzle (8) is 0.3～ 1.5m.

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