Dangerous waste incineration tail gas pollution reduction and carbon reduction treatment system and process

Abstract

The invention discloses a hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system which comprises a hazardous waste drying kiln, a cracking furnace, a high-temperature dust remover, an ash conveying device, an ash silo, a secondary combustion chamber, a waste heat boiler and a high-temperature fan. The hazardous waste drying kiln is connected with an inlet of the cracking furnace, the high-temperature dust remover comprises an upper box body, a dust removal chamber and an ash hopper, and an outlet of the cracking furnace is connected with the ash hopper; an outlet of the upper box body is connected with an inlet of the secondary combustion chamber, an outlet of the secondary combustion chamber is connected with the waste heat boiler, an inlet of the high-temperature fan is connected with the waste heat boiler, and an outlet is connected with the hazardous waste drying kiln. According to the hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system and process, most particulate matter in flue gas can be removed at the high temperature, pollutant emission is reduced, waste heat recovery is conducted on the flue gas with the particulate matter removed, blockage of a flue of a waste heat boiler in the heat exchange process can be effectively reduced, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hazardous waste treatment, and in particular relates to a system and process for reducing pollution and carbon emissions from hazardous waste incineration tail gas. Background Art

[0002] As the pace of economic construction is getting faster and faster, various hazardous wastes are generated in the production and construction process of China's industry or other industries. Many hazardous wastes are highly toxic, corrosive, and explosive, which will bring great harm to society. Against this background, the incineration disposal and purification process of hazardous wastes came into being and achieved relatively remarkable development results. However, it is undeniable that due to the large number of hazardous waste types and the continuous increase in the daily output of hazardous wastes in cities, hazardous waste treatment technology has developed rapidly, and incineration is currently the mainstream technology for hazardous waste disposal. After high-temperature incineration, the volume of hazardous waste will be reduced, and the toxic and harmful substances in it will be degraded or completely removed. At the same time, after high-temperature incineration, a large amount of high-temperature flue gas will be formed. At present, the heat in the high-temperature flue gas is not fully utilized, resulting in a large amount of heat loss, which is not conducive to the pollution reduction and carbon reduction treatment of incineration tail gas. Summary of the invention

[0003] In order to make full use of the heat in the flue gas from hazardous waste incineration and at the same time reduce pollution and carbon emissions from the incineration flue gas, the present invention discloses a system and process for reducing pollution and carbon emissions from hazardous waste incineration tail gas, which can remove most of the particulate matter in the flue gas at high temperature to reduce pollutant emissions, and recover waste heat from the flue gas with particulate matter removed, which can effectively reduce the blockage of the flue duct of the waste heat boiler during the heat exchange process and improve the heat exchange efficiency.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions: A system for reducing pollution and carbon emissions from hazardous waste incineration tail gas, comprising a hazardous waste drying kiln, a cracking furnace, a high-temperature dust collector, an ash conveying device, an ash bin, a secondary combustion chamber, a waste heat boiler, and a high-temperature fan. The hazardous waste drying kiln is connected to the inlet of the cracking furnace, the high-temperature dust collector comprises an upper box, a dust removal chamber, and an ash hopper, the outlet of the cracking furnace is connected to the ash hopper, the outlet of the upper box is connected to the inlet of the secondary combustion chamber, the outlet of the secondary combustion chamber is connected to the waste heat boiler, the inlet of the high-temperature fan is connected to the waste heat boiler, and the outlet is connected to the hazardous waste drying kiln.

[0005] Furthermore, a drying belt is provided in the middle of the hazardous waste drying kiln, and the drying belt is made of porous material. The hazardous waste moves forward on the drying belt. A high-temperature flue gas inlet is provided at the lower part of the hazardous waste drying kiln, a flue gas outlet is provided at the upper part, a hazardous waste inlet is provided at the front part, and a hazardous waste outlet is provided at the rear part. The hazardous waste inlet and the hazardous waste outlet are located at the upper part of the drying belt.

[0006] Furthermore, the upper box of the high-temperature dust collector is provided with a high-temperature clean air outlet, a high-temperature resistant dust removal element is installed in the dust removal chamber, a high-temperature flue gas inlet is opened on one side of the ash hopper, a smoke discharge port is provided at the bottom, and a rotary discharge valve is connected to the smoke discharge port. The high-temperature resistant dust removal element is one of a ceramic membrane, a metal membrane, and a metal filter bag.

[0007] Furthermore, the ash conveying device is a pneumatic ash conveying device or a screw conveyor.

[0008] Furthermore, the interior of the secondary combustion chamber is a high-aluminum refractory layer, the exterior is a heat-resistant steel plate, and the middle layer adopts a refractory brick structure.

[0009] The hazardous waste incineration tail gas treatment process of the above-mentioned hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system comprises the following steps: Step 1: After the hazardous waste is mixed, it enters the hazardous waste drying kiln to preheat the hazardous waste and evaporate some of the water. After entering the hazardous waste drying kiln, the hazardous waste moves forward on the drying belt. The high-temperature flue gas discharged from the waste heat hot pot enters the hazardous waste drying kiln and passes through the drying belt to preheat the hazardous waste. Step 2: The preheated hazardous waste enters the pyrolysis furnace, and the organic matter in the hazardous waste is pyrolyzed at high temperature. The small molecular organic gas and inorganic particles after pyrolysis enter the high-temperature dust collector 3 with the flue gas. The solid particles are removed by the high-temperature dust collector, and the particles enter the ash hopper and enter the ash conveying device through the rotary discharge valve. The incompletely burned waste gas enters the secondary combustion chamber; Step 3: The flue gas entering the secondary combustion chamber is fully burned, and the high-temperature flue gas enters the waste heat boiler, is discharged from the waste heat boiler after the first heat recovery, and enters the hazardous waste drying kiln under the action of the high-temperature fan for secondary utilization of waste heat. The flue gas discharged from the hazardous waste drying kiln undergoes subsequent flue gas treatment.

[0010] Furthermore, in the step 1, the forward movement rate of the drying belt is 1-3 m / min.

[0011] Furthermore, in the step 2, the temperature in the pyrolysis furnace is 300-600°C, and the dust removal temperature in the high-temperature dust collector 3 is 300-450°C.

[0012] Furthermore, in the step three, the temperature inside the second combustion chamber is 1000-1200°C, the exhaust temperature of the flue gas from the waste heat boiler is 180-240°C, and the temperature of the flue gas discharged from the hazardous waste drying kiln is 120-150°C.

[0013] The present invention discloses a system and process for reducing pollution and carbon emissions from hazardous waste incineration tail gas. After the hazardous waste is pyrolyzed in a pyrolysis furnace, flue gas dust removal is performed at high temperature. A high-temperature dust collector can remove more than 99% of solid particulate matter and soluble salt substances in the high-temperature flue gas, preventing the salt from being vaporized into a gaseous state at high temperature in the secondary combustion chamber and entering the waste heat boiler, where it forms a bond on the heat exchange panel of the waste heat boiler, affecting the heat exchange efficiency and improving the waste heat recovery efficiency of the high-temperature flue gas. The flue gas after heat recovery by the waste heat boiler enters the hazardous waste drying kiln for secondary waste heat utilization, thereby increasing heat recovery in the flue gas, minimizing the addition of extra heat in the hazardous waste disposal process, and reducing carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system according to the present invention; Figure 2 This is a schematic diagram of the structure of the hazardous waste drying kiln according to the present invention; Figure 3 This is a schematic diagram of the structure of the high-temperature dust collector described in the present invention.

[0015] Among them, 1- hazardous waste drying kiln, 2- cracking furnace, 3- high temperature dust collector, 4- ash conveying device, 5- ash storage, 6- secondary combustion chamber, 7- waste heat boiler, 8- high temperature fan, 101- drying belt, 102- high temperature flue gas inlet, 103- flue gas outlet, 104- hazardous waste inlet, 105- hazardous waste outlet, 301- upper box, 302- dust removal chamber, 303- ash hopper, 3011- high temperature clean gas outlet, 3021- high temperature resistant dust removal element, 3031- high temperature flue gas inlet, 3032- smoke dust discharge port, 3033- rotary discharge valve. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] like Figure 1-Figure 3As shown, a pollution reduction and carbon reduction treatment system for hazardous waste incineration tail gas includes a hazardous waste drying kiln 1, a cracking furnace 2, a high-temperature dust collector 3, an ash conveying device 4, an ash bin 5, a secondary combustion chamber 6, a waste heat boiler 7, and a high-temperature fan 8. The hazardous waste drying kiln 1 is connected to the inlet of the cracking furnace 2. A drying belt 101 is provided in the middle of the hazardous waste drying kiln 1. The drying belt 101 is made of porous material. The hazardous waste moves forward on the drying belt 101. A high-temperature flue gas inlet 102 is provided at the lower part of the hazardous waste drying kiln 1, a flue gas outlet 103 is provided at the upper part, a hazardous waste inlet 104 is provided at the front, and a hazardous waste outlet 105 is provided at the rear. The hazardous waste inlet 104 and the hazardous waste outlet 105 are located at the upper part of the drying belt 101; the high-temperature dust collector 3 includes an upper box body 301, a dust removal chamber 302, an ash hopper 303, and a cracking furnace 2 outlet is connected to the ash hopper 303, the outlet of the upper box body 301 is connected to the inlet of the secondary combustion chamber 6, the outlet of the secondary combustion chamber 6 is connected to the waste heat boiler 7, the inlet of the high-temperature fan 8 is connected to the waste heat boiler 7, and the outlet is connected to the hazardous waste drying kiln 1; the upper box body 301 is provided with a high-temperature clean gas outlet 3011, and a high-temperature resistant dust removal element 3021 is installed in the dust removal chamber 302. A high-temperature flue gas inlet 3031 is opened on one side of the ash hopper 303, and a smoke discharge port 3032 is provided at the bottom. A rotary discharge valve 3033 is connected to the smoke discharge port 3032, and the high-temperature resistant dust removal element 3021 is one of a ceramic membrane, a metal membrane, and a metal filter bag; the ash conveying device 4 is a pneumatic ash conveying device or a screw conveyor, the interior of the secondary combustion chamber 6 is a high-aluminum refractory layer, the exterior is a heat-resistant steel plate, and the middle layer adopts a refractory brick structure. Example

[0018] The hazardous waste incineration tail gas treatment process using the above-mentioned hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system includes the following steps: Step 1: After being mixed, the hazardous waste enters the hazardous waste drying kiln 1, where it is preheated and part of the water is evaporated. After entering the hazardous waste drying kiln 1, the hazardous waste moves forward on the drying belt 101 at a forward movement rate of 1-3 m / min. The high-temperature flue gas discharged from the waste heat hot pot 7 enters the hazardous waste drying kiln 1 and passes through the drying belt to preheat the hazardous waste. Step 2: The preheated hazardous waste enters the pyrolysis furnace 2, the temperature in the pyrolysis furnace 2 is 320°C, the organic matter in the hazardous waste is pyrolyzed at high temperature, the small molecular organic gas and inorganic particles after pyrolysis enter the high temperature dust collector 3 with the flue gas, the dust removal temperature in the high temperature dust collector 3 is 300°C, the solid particles are removed by the high temperature dust collector 3, the particles enter the ash hopper 303, and enter the ash conveying device 4 through the rotary discharge valve 3033, and the incompletely burned waste gas enters the secondary combustion chamber 6; Step three: The flue gas entering the secondary combustion chamber 6 is fully burned, and the high-temperature flue gas enters the waste heat boiler 7, is discharged from the waste heat boiler 7 after the first heat recovery, and enters the hazardous waste drying kiln 1 under the action of the high-temperature fan 8 for secondary utilization of waste heat, and the flue gas discharged from the hazardous waste drying kiln 1 undergoes subsequent flue gas treatment; wherein, the temperature in the secondary combustion chamber 6 is 1000°C, the flue gas outlet temperature of the waste heat boiler 7 is 184°C, and the flue gas temperature discharged from the hazardous waste drying kiln 1 is 123°C. Example

[0019] The hazardous waste incineration tail gas treatment process using the above-mentioned hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system includes the following steps: Step 1: After being mixed, the hazardous waste enters the hazardous waste drying kiln 1, where it is preheated and part of the water is evaporated. After entering the hazardous waste drying kiln 1, the hazardous waste moves forward on the drying belt 101 at a forward movement rate of 1-3 m / min. The high-temperature flue gas discharged from the waste heat hot pot 7 enters the hazardous waste drying kiln 1 and passes through the drying belt to preheat the hazardous waste. Step 2: The preheated hazardous waste enters the pyrolysis furnace 2, the temperature in the pyrolysis furnace 2 is 455°C, the organic matter in the hazardous waste is pyrolyzed at high temperature, the small molecular organic gas and inorganic particles after pyrolysis enter the high temperature dust collector 3 with the flue gas, the dust removal temperature in the high temperature dust collector 3 is 380°C, the solid particles are removed by the high temperature dust collector 3, the particles enter the ash hopper 303, and enter the ash conveying device 4 through the rotary discharge valve 3033, and the incompletely burned waste gas enters the secondary combustion chamber 6; Step three: The flue gas entering the secondary combustion chamber 6 is fully burned, and the high-temperature flue gas enters the waste heat boiler 7, is discharged from the waste heat boiler 7 after the first heat recovery, and enters the hazardous waste drying kiln 1 under the action of the high-temperature fan 8 for secondary utilization of waste heat, and the flue gas discharged from the hazardous waste drying kiln 1 undergoes subsequent flue gas treatment; wherein, the temperature in the secondary combustion chamber 6 is 1100°C, the flue gas outlet temperature of the waste heat boiler 7 is 215°C, and the flue gas temperature discharged from the hazardous waste drying kiln 1 is 136°C. Example

[0020] The hazardous waste incineration tail gas treatment process using the above-mentioned hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system includes the following steps: Step 1: After being mixed, the hazardous waste enters the hazardous waste drying kiln 1, where it is preheated and part of the water is evaporated. After entering the hazardous waste drying kiln 1, the hazardous waste moves forward on the drying belt 101 at a forward movement rate of 1-3 m / min. The high-temperature flue gas discharged from the waste heat hot pot 7 enters the hazardous waste drying kiln 1 and passes through the drying belt to preheat the hazardous waste. Step 2: The preheated hazardous waste enters the pyrolysis furnace 2, the temperature in the pyrolysis furnace 2 is 595°C, the organic matter in the hazardous waste is pyrolyzed at high temperature, the small molecular organic gas and inorganic particles after pyrolysis enter the high temperature dust collector 3 with the flue gas, the dust removal temperature in the high temperature dust collector 3 is 450°C, the solid particles are removed by the high temperature dust collector 3, the particles enter the ash hopper 303, and enter the ash conveying device 4 through the rotary discharge valve 3033, and the incompletely burned waste gas enters the secondary combustion chamber 6; Step three: the flue gas entering the secondary combustion chamber 6 is fully burned, and the high-temperature flue gas enters the waste heat boiler 7, is discharged from the waste heat boiler 7 after the first heat recovery, and enters the hazardous waste drying kiln 1 under the action of the high-temperature fan 8 for secondary utilization of waste heat, and the flue gas discharged from the hazardous waste drying kiln 1 undergoes subsequent flue gas treatment; wherein, the temperature in the secondary combustion chamber 6 is 1200°C, the flue gas outlet temperature of the waste heat boiler 7 is 238°C, and the flue gas temperature discharged from the hazardous waste drying kiln 1 is 148°C.

[0021] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for reducing pollution and carbon emissions from hazardous waste incineration tail gas, characterized in that: It includes a hazardous waste drying kiln, a cracking furnace, a high-temperature dust collector, an ash conveying device, an ash bin, a secondary combustion chamber, a waste heat boiler, and a high-temperature fan. The hazardous waste drying kiln is connected to the inlet of the cracking furnace. The high-temperature dust collector includes an upper box, a dust removal chamber, and an ash hopper. The outlet of the cracking furnace is connected to the ash hopper, the outlet of the upper box is connected to the inlet of the secondary combustion chamber, the outlet of the secondary combustion chamber is connected to the waste heat boiler, the inlet of the high-temperature fan is connected to the waste heat boiler, and the outlet is connected to the hazardous waste drying kiln.

2. A system for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 1, characterized in that: A drying belt is provided in the middle of the hazardous waste drying kiln, and the drying belt is made of porous material. The hazardous waste moves forward on the drying belt. A high-temperature flue gas inlet is provided at the lower part of the hazardous waste drying kiln, a flue gas outlet is provided at the upper part, a hazardous waste inlet is provided at the front part, and a hazardous waste outlet is provided at the rear part. The hazardous waste inlet and the hazardous waste outlet are located at the upper part of the drying belt.

3. A system for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 1, characterized in that: The upper box of the high-temperature dust collector is provided with a high-temperature clean air outlet, a high-temperature resistant dust removal element is installed in the dust removal chamber, a high-temperature flue gas inlet is opened on one side of the ash hopper, and a smoke discharge port is provided at the bottom. A rotary discharge valve is connected to the smoke discharge port. The high-temperature resistant dust removal element is one of a ceramic membrane, a metal membrane, and a metal filter bag.

4. A system for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 1, characterized in that: The ash conveying device is a pneumatic ash conveying device or a screw conveyor.

5. The system for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 1 is characterized in that: The interior of the secondary combustion chamber is a high-aluminum refractory layer, the exterior is a heat-resistant steel plate, and the middle layer adopts a refractory brick structure.

6. The hazardous waste incineration tail gas treatment process of the hazardous waste incineration tail gas pollution reduction and carbon reduction treatment system according to claim 1 is characterized in that: The following steps are involved: Step 1: After the hazardous waste is mixed, it enters the hazardous waste drying kiln to preheat the hazardous waste and evaporate some of the water. After entering the hazardous waste drying kiln, the hazardous waste moves forward on the drying belt. The high-temperature flue gas discharged from the waste heat hot pot enters the hazardous waste drying kiln and passes through the drying belt to preheat the hazardous waste. Step 2: The preheated hazardous waste enters the pyrolysis furnace, and the organic matter in the hazardous waste is pyrolyzed at high temperature. The small molecular organic gas and inorganic particles after pyrolysis enter the high-temperature dust collector 3 with the flue gas. The solid particles are removed by the high-temperature dust collector, and the particles enter the ash hopper and enter the ash conveying device through the rotary discharge valve. The incompletely burned waste gas enters the secondary combustion chamber; Step 3: The flue gas entering the secondary combustion chamber is fully burned, and the high-temperature flue gas enters the waste heat boiler, is discharged from the waste heat boiler after the first heat recovery, and enters the hazardous waste drying kiln under the action of the high-temperature fan for secondary utilization of waste heat. The flue gas discharged from the hazardous waste drying kiln undergoes subsequent flue gas treatment.

7. A process for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 6, characterized in that: In the step 1, the forward movement speed of the drying belt is 1-3 m / min.

8. A process for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 6, characterized in that: In the step 2, the temperature in the pyrolysis furnace is 300-600°C, and the dust removal temperature in the high-temperature dust collector 3 is 300-450°C.

9. A process for reducing pollution and carbon emissions from hazardous waste incineration tail gas according to claim 6, characterized in that: In the step three, the temperature inside the second combustion chamber is 1000-1200°C, the exhaust temperature of the flue gas from the waste heat boiler is 180-240°C, and the exhaust temperature of the flue gas from the hazardous waste drying kiln is 120-150°C.

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