阅读说明：本技术 二燃室燃烧及配风系统和方法 (Combustion and air distribution system and method for secondary combustion chamber ) 是由 夏杨 兰玉顺 刘维娜 王丹 于 2020-12-03 设计创作，主要内容包括：本发明公开了二燃室燃烧及配风系统和方法,系统包括：二燃室本体；包括燃烧器和燃烧器助燃风机的燃烧单元,燃烧器设置二燃室本体的侧壁上,燃烧器助燃风机与燃烧器相连接；包括二次风机、环形风管和多个配风支管的配风单元,环形风管环绕在二燃室本体的侧壁上,配风支管设置在环形风管上,且配风支管朝向二燃室本体内开口,二次风机与环形风管相连接。危险废物在回转窑内与助燃空气充分接触,完成干燥、燃烧和燃烬的全过程,燃烧过程产生大量烟气,烟气经过二燃室,二燃室内温度控制在1100摄氏度以上,烟气在环形风管和配风支管的作用下形成足够大的湍流度,并提供过剩空气量,同时保证烟气停留时间大于2s,确保烟气中有害物质充分分解。(The invention discloses a combustion and air distribution system and a method of a secondary combustion chamber, wherein the system comprises: a second combustion chamber body; the combustion unit comprises a combustor and a combustor combustion-supporting fan, the combustor is arranged on the side wall of the secondary combustion chamber body, and the combustor combustion-supporting fan is connected with the combustor; the air distribution unit comprises a secondary fan, an annular air pipe and a plurality of air distribution branch pipes, wherein the annular air pipe surrounds the side wall of the secondary combustion chamber body, the air distribution branch pipes are arranged on the annular air pipe and face the inner opening of the secondary combustion chamber body, and the secondary fan is connected with the annular air pipe. The dangerous waste is fully contacted with combustion air in the rotary kiln to complete the whole processes of drying, burning and burning-out, a large amount of flue gas is generated in the burning process, the flue gas passes through a secondary combustion chamber, the temperature in the secondary combustion chamber is controlled to be more than 1100 ℃, the flue gas forms enough turbulence under the action of an annular air pipe and an air distribution branch pipe, the surplus air quantity is provided, meanwhile, the retention time of the flue gas is ensured to be more than 2s, and the harmful substances in the flue gas are fully decomposed.)

1. A combustion and air distribution system of a secondary combustion chamber is characterized by comprising:

a second combustion chamber body;

the combustion unit comprises a combustor and a combustor combustion-supporting fan, the combustor is arranged on the side wall of the secondary combustion chamber body, and the combustor combustion-supporting fan is connected with the combustor;

the air distribution unit comprises a secondary fan, an annular air pipe and a plurality of air distribution branch pipes, the annular air pipe surrounds the side wall of the secondary combustion chamber body, the air distribution branch pipes are arranged on the annular air pipe and face the inner opening of the secondary combustion chamber body, and the secondary fan is connected with the annular air pipe.

2. The secondary combustion chamber combustion and air distribution system of claim 1, wherein the back-reflection angle β of the air distribution branch pipe in the direction perpendicular to the cross section of the secondary combustion chamber body is 20 ° -45 °, and the tangential angle α of the air distribution branch pipe in the direction horizontal to the cross section of the secondary combustion chamber body is 15 ° -30 °.

3. The secondary combustion chamber combustion and air distribution system of claim 1, wherein the number of said plurality of air distribution branch pipes is 8-10.

4. A secondary combustion chamber combustion and air distribution system as set forth in any of claims 1-3 wherein said burner includes a compressed air injection port, a hazardous waste injection port, a fuel injection port, and an igniter disposed on said burner, said compressed air injection port, said hazardous waste injection port, and said fuel injection port all facing into said secondary combustion chamber body.

5. The secondary combustion chamber combustion and air distribution system of claim 4, wherein the fuel injection ports include natural gas injection ports and diesel injection ports.

6. The secondary combustion chamber combustion and air distribution system of claim 4, wherein the number of burners is 1-4.

7. The secondary combustion chamber combustion and air distribution system of any of claims 1-3, further comprising: dangerous waste liquid spray gun, start diaphragm pump and dangerous waste liquid buffer tank, dangerous waste liquid spray gun sets up the bottom of two combustion chambers bodies, just dangerous waste liquid spray gun orientation two combustion chambers are originally internal, it sets up to start the diaphragm pump dangerous waste liquid spray gun with between the dangerous waste liquid buffer tank.

8. The secondary combustion chamber combustion and air distribution system of any of claims 1-3, further comprising: the emergency exhaust device is arranged at the top of the second combustion chamber body and comprises an emergency exhaust chimney, an end cover and an emergency exhaust dynamic device, wherein the end cover is arranged at the top end of the emergency exhaust chimney, and the end cover is connected with the emergency exhaust dynamic device.

9. The secondary combustion chamber combustion and air distribution system of any of claims 1-3, further comprising: and the automatic control unit is respectively connected with the combustion unit and the air distribution unit through electric signals.

10. A method for burning flue gas of a rotary kiln by using the secondary combustion chamber combustion and air distribution system of any one of claims 1 to 9, which is characterized by comprising the following steps:

(1) air is sent into the annular air pipe through the secondary fan and then enters the secondary combustion chamber body through the air distribution branch pipe;

(2) and introducing the flue gas in the rotary kiln into a second combustion chamber body, and combusting under the action of a combustor.

Technical Field

The invention belongs to the technical field of hazardous waste treatment, and particularly relates to a combustion and air distribution system and method for a secondary combustion chamber.

Background

With the development of industry, the discharge of dangerous waste in industrial production process is increasing. It is estimated that the worldwide annual production of hazardous waste is 3.3 million tons. The hazards presented by hazardous waste mainly include the following:

1. destroying the ecological environment. The dangerous waste which is randomly discharged and stored can pollute water and soil and reduce the environmental function level of the area under the long-term infiltration and diffusion action of rainwater and groundwater.

2. Affecting human health. Hazardous waste causes toxicity through ingestion, inhalation, skin absorption and eye contact, or causes dangerous events such as burning, explosion and the like; long-term hazards include long-term poisoning, carcinogenesis, teratogenicity, mutagenicity, etc. resulting from repeated exposure.

3. Restricting sustainable development. The pollution of atmosphere, water source, soil and the like caused by the non-treatment or non-standard treatment of hazardous wastes can become a bottleneck for restricting economic activities.

At present, when dangerous wastes are treated, an incinerator and a rotary kiln are mainly used for incineration treatment. The incineration method not only can completely eliminate the toxicity and the harmfulness of the waste, but also can reduce the volume of dangerous waste to the maximum extent, and is the most powerful means for harmlessness and reduction of the waste.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, one object of the present invention is to provide a combustion and air distribution system and method for a secondary combustion chamber, wherein hazardous waste is fully contacted with combustion air in a rotary kiln to complete the whole process of drying, combustion and burning-out, a large amount of flue gas is generated in the combustion process, the temperature in the secondary combustion chamber is controlled to be over 1100 ℃, the flue gas forms a sufficient turbulence degree under the action of an annular air pipe and a plurality of air distribution branch pipes, and an excess air amount is provided, and simultaneously, the retention time of the flue gas is ensured to be more than 2s, so that the harmful substances in the flue gas are fully decomposed.

In one aspect of the invention, a secondary combustion chamber combustion and air distribution system is provided. According to an embodiment of the invention, the system comprises:

a second combustion chamber body;

the combustion unit comprises a combustor and a combustor combustion-supporting fan, the combustor is arranged on the side wall of the secondary combustion chamber body, and the combustor combustion-supporting fan is connected with the combustor;

the air distribution unit comprises a secondary fan, an annular air pipe and a plurality of air distribution branch pipes, the annular air pipe surrounds the side wall of the secondary combustion chamber body, the air distribution branch pipes are arranged on the annular air pipe and face the inner opening of the secondary combustion chamber body, and the secondary fan is connected with the annular air pipe.

According to the combustion and air distribution system of the secondary combustion chamber, the hazardous wastes are fully contacted with combustion-supporting air in the rotary kiln to complete the whole process of drying, combustion and burning-out, a large amount of flue gas is generated in the combustion process, the flue gas enters the secondary combustion chamber, and the residence time of the flue gas in the secondary combustion chamber is more than 2s under the action of the annular air pipe and the plurality of air distribution branch pipes, so that the flue gas is completely combusted under the action of excessive air, and harmful substances are fully decomposed. Particularly, the flue gas gets into from the second combustion chamber bottom under the condition that does not have the vortex, under the effect of draught fan, from lower to upper comparatively regular outflow second combustion chamber, and the air distribution branch pipe of this application with the cross-section of second combustion chamber body is certain angle to the air that makes through air distribution branch pipe drum-in is certain angle with the flow direction that gets into second combustion chamber interior flue gas, thereby makes the air of going into through air distribution branch pipe form the vortex to the flue gas that lets in second combustion chamber, makes the flue gas and the air intensive mixing that lets in through air distribution branch pipe, forms great torrent, flows out second combustion chamber with the mode of whirl, and then has increased the dwell time of flue gas in second combustion chamber. Meanwhile, the air distribution unit can form enough turbulence in the secondary combustion chamber while providing the excess air, so that the smoke and the air are fully mixed to ensure that the harmful gas is burnt more thoroughly. Specifically, as mentioned above, the air (secondary air) blown in through the air distribution branch pipe forms a certain angle with the flow direction of the flue gas entering the secondary combustion chamber, so that the air blown in through the air distribution branch pipe forms turbulence to the flue gas entering the secondary combustion chamber, two fluids are mixed with each other (the flue gas is one fluid, the blown secondary air is one fluid), the fluid particles do irregular motion and collide with each other to form a vortex, and the turbulence degree is enhanced.

In addition, the second combustion chamber combustion and air distribution system according to the above embodiment of the present invention may further have the following additional technical features:

in some embodiments of the invention, the back-reflection angle beta of the air distribution branch pipe in the vertical direction of the cross section of the second combustion chamber body is 20-45 degrees, and the tangential angle alpha of the air distribution branch pipe in the horizontal direction of the cross section of the second combustion chamber body is 15-30 degrees. Therefore, the air blown in through the air distribution branch pipe forms turbulent flow on the smoke entering the secondary combustion chamber by the aid of the back-reflection angle and the tangential angle in the range, the smoke is fully mixed with the air introduced through the air distribution branch pipe to form large turbulent flow, the smoke flows out of the secondary combustion chamber in a rotational flow mode, residence time and turbulence degree of the smoke in the secondary combustion chamber are further increased, and the smoke entering the secondary combustion chamber is fully combusted.

In some embodiments of the invention, the number of the plurality of air distribution branches is 8-10. Therefore, the number of the air distribution branch pipes in the range further increases the retention time and turbulence of the flue gas in the secondary combustion chamber, so that the flue gas entering the secondary combustion chamber is more fully combusted.

In some embodiments of the invention, the burner includes a compressed air injection port, a hazardous waste injection port, a fuel injection port, and an igniter disposed on the burner, the compressed air injection port, the hazardous waste injection port, and the fuel injection port all facing into the secondary combustion chamber body. Therefore, the full combustion of the flue gas is realized, and the combustion of the dangerous waste liquid is also realized.

In some embodiments of the invention, the fuel injection ports comprise natural gas injection ports and diesel injection ports.

In some embodiments of the invention, the number of burners is 1 to 4.

In some embodiments of the invention, the system further comprises: dangerous waste liquid spray gun, start diaphragm pump and dangerous waste liquid buffer tank, dangerous waste liquid spray gun sets up the bottom of two combustion chambers bodies, just dangerous waste liquid spray gun orientation two combustion chambers are originally internal, it sets up to start the diaphragm pump dangerous waste liquid spray gun with between the dangerous waste liquid buffer tank.

In some embodiments of the invention, the system further comprises: the emergency exhaust device is arranged at the top of the second combustion chamber body and comprises an emergency exhaust chimney, an end cover and an emergency exhaust dynamic device, wherein the end cover is arranged at the top end of the emergency exhaust chimney, and the end cover is connected with the emergency exhaust dynamic device.

In some embodiments of the invention, the system further comprises: and the automatic control unit is respectively connected with the combustion unit and the air distribution unit through electric signals.

In another aspect of the invention, the invention provides a method for burning flue gas of a rotary kiln by using the secondary combustion chamber combustion and air distribution system in the embodiment. According to an embodiment of the invention, the method comprises:

(1) air is sent into the annular air pipe through the secondary fan and then enters the secondary combustion chamber body through the air distribution branch pipe;

(2) and introducing the flue gas in the rotary kiln into a second combustion chamber body, and combusting under the action of a combustor.

According to the method for burning the flue gas of the rotary kiln, the hazardous waste is fully contacted with combustion-supporting air in the rotary kiln to complete the whole processes of drying, burning and burning-out, a large amount of flue gas is generated in the burning process, and the flue gas stays in the secondary chamber for more than 2s under the action of the annular air pipe and the plurality of air distribution branch pipes, so that the flue gas is completely burned under the action of excessive air, and harmful substances are fully decomposed.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural view of a combustion and air distribution system of a second combustion chamber according to an embodiment of the invention.

Fig. 2 is a schematic partial (cross-sectional horizontal direction) structure diagram of a combustion and air distribution system of a second combustion chamber according to an embodiment of the invention.

Fig. 3 is a schematic partial (cross-sectional vertical direction) structure diagram of a combustion and air distribution system of a second combustion chamber according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In one aspect of the invention, a secondary combustion chamber combustion and air distribution system is provided. According to an embodiment of the invention, with reference to fig. 1, the system comprises: the second combustion chamber comprises a second combustion chamber body 1, a combustion unit and an air distribution unit.

According to an embodiment of the present invention, referring to fig. 1, a second combustion chamber body 1 is a vertical hollow cylindrical structure.

According to an embodiment of the present invention, referring to fig. 1, the combustion unit includes a burner 8 and a burner combustion fan 10, the burner 8 is disposed on a side wall of the secondary combustion chamber body 1, and the burner combustion fan 10 is connected to the burner 8. The burner is connected with the second combustion chamber body through a flange. The combustion-supporting fan of the burner provides necessary combustion-supporting air for the combustion of the flue gas entering the second combustion chamber, and the flue gas is fully combusted in the burner under the assistance of the combustion-supporting fan of the burner.

In one embodiment of the invention, the burner comprises a compressed air injection port, a hazardous waste injection port, a fuel injection port and an igniter 9 arranged on the burner, wherein the compressed air injection port, the hazardous waste injection port and the fuel injection port all face into the secondary combustion chamber body. From this, make fuel and dangerous waste liquid fully atomize and get into two combustion chambers burning through the flow pressure of adjusting dangerous waste liquid, fuel and compressed air's pressure, then fully burn under the effect of lighter, also make the flue gas that gets into two combustion chambers fully burn in the combustor simultaneously. Therefore, the full combustion of the flue gas is realized, and the combustion of the dangerous waste liquid is also realized.

In yet another embodiment of the present invention, the fuel injection ports include natural gas injection ports and diesel injection ports. In the embodiment of the present invention, the specific type of the above fuel is not particularly limited, and those skilled in the art can freely select the fuel according to actual needs, and natural gas and diesel are only one specific example.

In yet another embodiment of the invention, the igniter is a high energy igniter connected to the burner body by a flange. The high-energy igniter comprises an ignition electrode which is pushed into and pulled out of the second combustion chamber body through a pneumatic device. Further, the burner is provided with a flame detection device (not shown in the figures).

In the embodiment of the present invention, the number of the burners is not particularly limited, and those skilled in the art can optionally select the number according to actual needs, and as a preferred scheme, the number of the burners is 1 to 4, preferably 2, and two burners are oppositely installed (cross section of the secondary combustion chamber) and staggered by a certain angle, so as to avoid overlapping of flames. In yet another embodiment of the present invention, the burners are combined burners, and each burner is configured with a set of valve sets. The number of the combustion fan of the burner is not particularly limited, and the person in the field can select the number at will according to actual conditions, so that a plurality of burners can share one combustion fan, and each burner can be provided with one combustion fan.

According to an embodiment of the present invention, referring to fig. 1, the air distribution unit includes a secondary air fan 7, an annular air duct 5 and a plurality of air distribution branch ducts 6, the annular air duct 5 surrounds the sidewall of the secondary combustion chamber body, the air distribution branch ducts 6 are disposed on the annular air duct 5, the air distribution branch ducts open towards the interior of the secondary combustion chamber body, and the secondary air fan 7 is connected with the annular air duct 5. Air is sent into the annular air pipe through the secondary fan and then enters the secondary combustion chamber body through the air distribution branch pipe. The retention time of the flue gas entering the secondary combustion chamber in the secondary combustion chamber is more than 2s under the action of the annular air pipe and the plurality of air distribution branch pipes, so that the flue gas is completely combusted under the action of excess air, and harmful substances are fully decomposed. Particularly, the smoke enters from the bottom of the secondary combustion chamber without turbulence and regularly flows out of the secondary combustion chamber from bottom to top, the air distribution branch pipe forms a certain angle with the cross section of the secondary combustion chamber body, so that air (secondary air) blown in through the air distribution branch pipe forms a certain angle with the flowing direction of the smoke entering the secondary combustion chamber, the air blown in through the air distribution branch pipe forms turbulence to the smoke introduced into the secondary combustion chamber, the smoke and the air introduced through the air distribution branch pipe are fully mixed to form larger turbulence, the smoke flows out of the secondary combustion chamber in a rotational flow mode, and the residence time of the smoke in the secondary combustion chamber is prolonged. Meanwhile, the air distribution unit can form enough turbulence in the secondary combustion chamber while providing the excess air, so that the harmful gas and the air are fully mixed to ensure that the harmful gas is burnt more thoroughly. Specifically, as mentioned above, the air (secondary air) blown in through the air distribution branch pipe forms a certain angle with the flow direction of the flue gas entering the secondary combustion chamber, so that the air blown in through the air distribution branch pipe forms turbulence to the flue gas entering the secondary combustion chamber, two fluids are mixed with each other (the flue gas is one fluid, the blown secondary air is one fluid), the fluid particles do irregular motion and collide with each other to form a vortex, and the turbulence degree is enhanced.

In one embodiment of the invention, the air distribution branch pipe forms an included angle with the wall of the secondary combustion chamber, and the annular air pipe surrounds the secondary combustion chamber for a circle and is fixed on the secondary combustion chamber through a bracket.

In still another embodiment of the present invention, referring to fig. 2 to 3, a back-reflection angle β of the air distribution branch pipe in a direction perpendicular to the cross section of the second combustion chamber body is 20 ° to 45 °, and a tangential angle α of the air distribution branch pipe in a direction horizontal to the cross section of the second combustion chamber body is 15 ° to 30 °. Therefore, the air blown in through the air distribution branch pipe forms turbulent flow on the smoke entering the secondary combustion chamber by the aid of the back-reflection angle and the tangential angle in the range, the smoke is fully mixed with the air introduced through the air distribution branch pipe to form large turbulent flow, the smoke flows out of the secondary combustion chamber in a rotational flow mode, residence time and turbulence degree of the smoke in the secondary combustion chamber are further increased, and the smoke entering the secondary combustion chamber is fully combusted. The inventors have found that if the tangential angle α is less than 15 °, the flue gas residence time is affected, leading to a reduction in turbulence; if the tangential angle alpha is greater than 30 deg., a reduction in turbulence results. If the angle of incidence β is less than 20 °, a reduction in turbulence is caused; if the angle of incidence β is greater than 45 °, it results in a reduction in both turbulence and smoke residence time.

In fig. 2 and 3, 14 is a second combustion chamber wall.

As a preferable scheme, the annular air pipe and the secondary combustion chamber are fixed through a support, 8-10 air distribution branch pipes are arranged on the periphery of the annular air pipe, the air distribution branch pipes are connected with the annular air pipe and the secondary combustion chamber in a welding mode, the tangential angle alpha of each air distribution branch pipe is 20 degrees (the horizontal direction of the section of the secondary combustion chamber), and the back-reflection angle beta is 30 degrees (the vertical direction of the section of the secondary combustion chamber).

In the embodiment of the present invention, the number of the air distribution branch pipes is not particularly limited, and a person skilled in the art may optionally select the number according to actual needs, and as a preferable scheme, the number of the plurality of air distribution branch pipes is 8 to 10. Therefore, the number of the air distribution branch pipes in the range further increases the retention time and turbulence of the flue gas in the secondary combustion chamber, so that the flue gas entering the secondary combustion chamber is more fully combusted.

Further, with reference to fig. 1, the system further comprises: dangerous waste liquid spray gun 11, start diaphragm pump 12 and dangerous waste liquid buffer tank 13, dangerous waste liquid spray gun 11 sets up the bottom of second combustion chamber body, just dangerous waste liquid spray gun orientation this internally of second combustion chamber, start diaphragm pump 12 and set up dangerous waste liquid spray gun 11 with between the dangerous waste liquid buffer tank 13. When the temperature in the secondary combustion chamber reaches the temperature (1100 ℃) required by national regulations, the hazardous waste liquid passes through the pneumatic diaphragm pump and is sprayed into the bottom of the secondary combustion chamber through the hazardous waste liquid spray gun, so that the problem of coking at the tail of the kiln is solved, and the inner wall of the secondary combustion chamber is lined with refractory materials.

Further, with reference to fig. 1, the system further comprises: the emergency exhaust device is arranged at the top of the second combustion chamber body and comprises an emergency exhaust chimney 3, an end cover 2 and an emergency exhaust pneumatic device 4, wherein the end cover 2 is arranged at the top end of the emergency exhaust chimney 3, and the end cover 2 is connected with the emergency exhaust pneumatic device 4. Further, the quick exhaust device further includes a pressure gauge (not shown in the figure) for detecting the pressure in the secondary chamber. The emergency exhaust device is controlled by the air cylinder, when the pressure in the secondary combustion chamber reaches a set pressure value, a site pressure signal is fed back to the DCS, the emergency exhaust actuating device is automatically controlled through the linkage, the compressed air drives the air cylinder to open the end cover, smoke is discharged, pressure is released, and the safety of a combustion system of the secondary combustion chamber and the site is guaranteed. The compressed air for the pneumatic device is provided by the plant.

Further, the system further comprises: and the automatic control unit (not shown in the figure) is respectively connected with the combustion unit and the air distribution unit through electric signals and is used for controlling the combustion unit and the air distribution unit.

In an embodiment of the present invention, the automatic control unit is respectively connected to the combustion unit, the air distribution unit and the emergency exhaust device through electrical signals, and is configured to control the combustion unit, the air distribution unit and the emergency exhaust device.

Further, the system further comprises: and the flue gas outlet 15 is arranged at the tail end of the secondary combustion chamber body 1, and the flue gas outlet 15 is a flue gas outlet of the pressure in the secondary combustion chamber under the normal condition. After the flue gas from the rotary kiln and the hazardous waste liquid entering the secondary combustion chamber from the combustor are sufficiently combusted in the secondary combustion chamber, the flue gas goes to a tail gas treatment facility at the tail end through a flue gas outlet 15 for tail gas treatment.

According to the combustion and air distribution system of the secondary combustion chamber, the hazardous wastes are fully contacted with combustion-supporting air in the rotary kiln to complete the whole process of drying, combustion and burning-out, a large amount of flue gas is generated in the combustion process, the flue gas enters the secondary combustion chamber, and the residence time of the flue gas in the secondary combustion chamber is more than 2s under the action of the annular air pipe and the plurality of air distribution branch pipes, so that the flue gas is completely combusted under the action of excessive air, and harmful substances are fully decomposed. Particularly, the flue gas gets into from the second combustion chamber bottom under the condition that does not have the vortex, under the effect of draught fan, from lower to upper comparatively regular outflow second combustion chamber, and the air distribution branch pipe of this application with the cross-section of second combustion chamber body is certain angle to the messenger is certain angle through air (overgrate air) that the air distribution branch pipe was bloated and the flow direction that gets into second combustion chamber interior flue gas, thereby makes the air that the air distribution branch pipe was bloated form the vortex to the flue gas that lets in second combustion chamber, makes the flue gas and the air intensive mixing that lets in through the air distribution branch pipe, forms great torrent to the mode of whirl flows out second combustion chamber, and then has increased the dwell time of flue gas in second combustion chamber. Meanwhile, the air distribution unit can form enough turbulence in the secondary combustion chamber while providing the excess air, so that the harmful gas and the air are fully mixed to ensure that the harmful gas is burnt more thoroughly. Specifically, as mentioned above, the air (secondary air) blown in through the air distribution branch pipe forms a certain angle with the flow direction of the flue gas entering the secondary combustion chamber, so that the air blown in through the air distribution branch pipe forms turbulence to the flue gas entering the secondary combustion chamber, two fluids are mixed with each other (the flue gas is one fluid, the blown secondary air is one fluid), the fluid particles do irregular motion and collide with each other to form a vortex, and the turbulence degree is enhanced.

In still another aspect of the present invention, the present invention provides a method for burning flue gas of a rotary kiln by using the combustion and air distribution system of the second combustion chamber described in the above embodiments. According to an embodiment of the invention, the method comprises:

(1) air is sent into the annular air pipe through the secondary fan and then enters the secondary combustion chamber body through the air distribution branch pipe;

(2) and introducing the flue gas in the rotary kiln into a second combustion chamber body, and combusting under the action of a combustor.

According to the method for burning the flue gas of the rotary kiln, the hazardous waste is fully contacted with combustion-supporting air in the rotary kiln to complete the whole processes of drying, burning and burning-out, a large amount of flue gas is generated in the burning process, and the flue gas stays in the secondary chamber for more than 2s under the action of the annular air pipe and the plurality of air distribution branch pipes, so that the flue gas is completely burned under the action of excessive air, and harmful substances are fully decomposed.

The working process of the combustion and air distribution system of the second combustion chamber of the embodiment of the invention is as follows:

(a) air (or material pit air) is sent into the annular air pipe through the secondary fan and enters the secondary combustion chamber through the air distribution branch pipe, high turbulence is formed, the retention time of the flue gas in the secondary combustion chamber is prolonged, and harmful substances in the flue gas are more thoroughly burnt.

(b) The second combustion chamber is provided with a plurality of burners, and the plurality of burners are oppositely arranged (the cross section of the second combustion chamber) and staggered by a certain angle, so that the overlapping of flames is avoided. The burner is a combined burner, when the burner is started, a combustion-supporting fan of the burner is started, and then the flow, pressure and compressed air pressure of fuel are regulated by an automatic control system, so that the fuel (light diesel oil, natural gas or other fuel) is fully atomized and enters a secondary combustion chamber for combustion. When the temperature of the secondary combustion chamber reaches the temperature (1100 ℃) required by national regulations, the dangerous waste liquid can be sprayed into the secondary combustion chamber through a dangerous waste liquid jet orifice of the combustor to be completely incinerated.

(c) When the temperature in the secondary combustion chamber reaches the temperature (1100 ℃) required by national regulations, the hazardous waste liquid passes through the pneumatic diaphragm pump and is sprayed into the bottom of the secondary combustion chamber through the hazardous waste liquid spray gun, so as to achieve the aim of decoking.

(d) When the pressure in the secondary combustion chamber reaches a set pressure value, a pressure signal (pressure gauge) of the emergency exhaust device is fed back to the DCS, the emergency exhaust actuating device is automatically controlled through the linkage, the end cover is opened, the smoke is exhausted, and the safety of a secondary combustion chamber combustion system and the site is ensured. Under normal pressure, flue gas from the rotary kiln and hazardous waste liquid entering the secondary combustion chamber from the combustor are fully combusted in the secondary combustion chamber, and then the flue gas passes through a flue gas outlet 15 to a tail gas treatment facility at the tail end for tail gas treatment.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.