Harmless combustion chamber and heat treatment system comprising same

Abstract

The invention relates to the technical field of waste pyrolysis, in particular to a harmless combustion chamber and a heat treatment system comprising the same. The harmless combustion chamber comprises a combustion chamber (11), a settling chamber (12), a high-temperature flue gas outlet (13), an air mixing port (14) and a secondary cracker (15), the secondary cracker (15) is positioned in the settling cavity (12) and is provided with a cracker gas inlet pipe (151) and a cracker gas outlet pipe (152); an annular flue gas channel (16) for high-temperature flue gas to pass through is reserved between the outer wall of the secondary cracker (15) and the inner wall of the settling cavity (12); and air mixing ports (14) are formed in the upper part and the lower part of the secondary cracker (15). According to the harmless combustion chamber, the settling cavity of the harmless combustion chamber is improved, so that the harmless combustion chamber has the function of implementing secondary high-temperature pyrolysis on pyrolysis gas, heat of high-temperature flue gas is fully utilized, meanwhile, the temperature adjusting air distribution amount can be reduced, and the dust falling capacity of the settling cavity is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of waste pyrolysis, and particularly to a harmless combustion chamber and a heat treatment system containing the combustion chamber. Background Art

[0002] When heat-treating waste tires and waste batteries, it is often necessary to perform secondary cracking on the pyrolysis products. A continuous pyrolysis system and method for whole waste tires disclosed in Chinese Patent Document CN109628120A: The high-temperature oil and gas generated by the pyrolysis of waste tires first enter a heavy oil condensation tank, and high-temperature heavy oil is obtained through condensation. Then it enters a light oil condensation tank to obtain light oil. Finally, the non-condensable gas generated is transported to a hot air heater through a light oil and gas outlet for use as fuel. The obtained high-temperature heavy oil then re-enters the inner spiral reaction kettle with the waste tires and is secondarily cracked to generate light oil. This solution uses heavy oil as a heating medium to achieve the secondary cracking of heavy oil into light oil with higher economic value. A method for harmless and resource recovery treatment of waste lithium battery electrolyte disclosed in Chinese Patent Document CN114497794A: Under the protection of carbon dioxide or inert gas, the discharged waste lithium battery is heated, and the volatilized electrolyte is condensed and recovered and then pyrolyzed. The pyrolysis gas generated by the pyrolysis treatment is secondarily pyrolyzed, and finally the obtained pyrolysis gas is cooled and stored for reuse as a chemical synthesis raw material gas resource.

[0003] For biomass, secondary cracking treatment of its pyrolysis gas is an even more commonly used technical means. For example, a method for secondary cracking of biomass disclosed in Chinese Patent Document CN103557517A: First, the biomass is thermally decomposed and gasified to obtain a combustible mixed gas, and then the combustible mixed gas is catalytically cracked at a temperature of 890°C - 1200°C to crack the hydrocarbon compounds with larger molecular weights to obtain low-carbon molecular combustible gas. Finally, the low-carbon molecular combustible gas is combusted or collected. A secondary high-temperature cracking and waste heat recovery system for biomass pyrolysis gas disclosed in Chinese Patent Document CN104877713A performs catalytic cracking at a temperature of 1100 - 1200°C.

[0004] Secondly, for waste synthetic resins such as waste plastics or waste rubbers, wax-like substances are often generated during pyrolysis, causing pipeline blockages. A pyrolysis oil production system for waste materials disclosed in Chinese Patent Document CN114127234A is provided with a wax separator on the upper transfer device between the primary pyrolysis device and the secondary pyrolysis device to separate high-boiling wax components from pyrolysis gases with different carbon atom numbers. The oil separation device is connected to the wax separator to condense the pyrolysis gases to separate oil. The pyrolysis temperature of the primary pyrolysis device is preferably 400°C, and the pyrolysis temperature of the secondary pyrolysis device is preferably 550°C. An anti-blocking pyrolysis oil vapor condensation device disclosed in Chinese Patent Document CN218357445U is used for the pyrolysis of waste tires. A scraping wall spiral is arranged in the connecting pipe connected to the tail end of the pyrolysis furnace to prevent pipeline blockage.

[0005] In summary, in the prior art, one way to perform secondary pyrolysis on pyrolysis products is to return them to the original pyrolysis furnace, but this method only prolongs the pyrolysis time, and the improvement of pyrolysis effect may not be obvious. Another way to perform secondary pyrolysis on pyrolysis products is to set up a secondary pyrolysis furnace, supplemented with a catalyst and a higher treatment temperature. This method is a generally recognized secondary pyrolysis mode in the industry, but it is relatively energy-consuming. Summary of the Invention

[0006] The first object of the present invention is to provide a harmless combustion chamber with a settling chamber, which uses the high temperature at the flue gas outlet of the harmless combustion chamber to provide heat source for secondary pyrolysis, so as to make full use of the heat of the high-temperature flue gas while reducing the temperature regulation air distribution volume and enhancing the dust removal ability of the settling chamber.

[0007] To achieve the above object, the technical solution of the present invention is as follows: A harmless combustion chamber, comprising A combustion chamber, which provides a combustion space for pyrolysis gas or non-condensable gas generated by heat treatment and generates high-temperature flue gas; A settling chamber, located at one end of the combustion chamber, for removing dust from the high-temperature flue gas; A high-temperature flue gas outlet, located above the settling chamber, for guiding the high-temperature flue gas out of the settling chamber; An air mixing port, for mixing air in the high-temperature flue gas to reduce the temperature of the high-temperature flue gas to the required heat treatment temperature; It further includes A secondary pyrolyzer, located in the settling chamber, having a pyrolyzer inlet pipe and a pyrolyzer outlet pipe; An annular flue gas passage for the high-temperature flue gas to pass through is left between the outer wall of the secondary pyrolyzer and the inner wall of the settling chamber; Air mixing ports are arranged above and below the secondary pyrolyzer.

[0008] The inventive concept of this application lies in that: since the high-temperature flue gas generated in the combustion chamber needs to be mixed with air to reduce the temperature of the high-temperature flue gas to the required heat treatment temperature, a secondary cracker is arranged at the upper part of the sedimentation chamber, and the high-temperature part of the sedimentation chamber is used to reduce the temperature of the high-temperature flue gas. During use, first, the high-temperature flue gas at about 1000 °C is cooled to the temperature required for secondary cracking (600 - 800 °C) by the air mixing port below the secondary cracker, and then the high-temperature flue gas is cooled again to the temperature required for pyrolysis (500 - 700 °C) by the air mixing port above the secondary cracker. Since the secondary cracker consumes part of the heat energy, the air volume for temperature adjustment can be correspondingly reduced, and the subsequent tail gas treatment load is also correspondingly reduced.

[0009] On the other hand, due to the setting of the secondary cracker, it is equivalent to increasing the contact surface between the sedimentation chamber and the high-temperature flue gas, which can play a role in reducing the dust amount of the high-temperature flue gas.

[0010] Secondly, the high-temperature flue gas is mixed in the annular flue gas channel between the outer wall of the secondary cracker and the inner wall of the sedimentation chamber. Due to the narrowing of the space, the air for temperature adjustment can be more fully in contact with the high-temperature flue gas, making the temperature distribution of the high-temperature flue gas more uniform.

[0011] As a preferred solution, the secondary cracker has a cylindrical outer shell, and the diameter of the cylindrical outer shell is not greater than 2 / 3 of the diameter of the sedimentation chamber. Since it is necessary to ensure the smooth passage of the high-temperature flue gas, the cross-section of the secondary cracker should not be too large.

[0012] As a preferred solution, the bottom of the secondary cracker extends at most to 1 / 2 of the height of the sedimentation chamber, otherwise the surface of the secondary cracker is prone to ash accumulation.

[0013] As a preferred solution, the inside of the secondary cracker is filled with a catalyst, and the catalyst helps to improve the secondary cracking efficiency of the pyrolysis gas.

[0014] As a preferred solution, a cracker support platform for supporting the secondary cracker is provided inside the sedimentation chamber. The surface of the cracker support platform is covered with through holes for the high-temperature flue gas to pass through. The air mixing port below the secondary cracker is located at the bottom of the cracker support platform. Another function of the cracker support platform is to reduce the dust of the high-temperature flue gas, and the air mixing port below the secondary cracker can reduce the probability of ash accumulation at the bottom of the cracker support platform.

[0015] As a preferred solution, a cracker fixing bracket is provided inside the sedimentation chamber, which is located between the side wall of the secondary cracker and the inner wall of the sedimentation chamber and is used to limit the secondary cracker to prevent it from shaking significantly.

[0016] As a preferred solution, a cracker access port is opened at the top of the sedimentation chamber, and the cracker access port is equipped with an access port sealing cover for the maintenance or replacement of the catalyst of the secondary cracker.

[0017] Another object of the present invention is to provide a heat treatment system including the harmless combustion chamber, which comprises a harmless combustion chamber, a combustion chamber cooling air configuration unit, a pyrolysis unit, a pyrolysis gas dust removal unit, a spray cooling unit, and a tail gas treatment unit. The combustion chamber cooling air configuration unit is divided into two independent branches, which are respectively communicated with the air mixing ports above and below the secondary pyrolyzer. The pyrolysis gas dust removal unit has an air outlet end, and the air outlet end is communicated with the pyrolyzer inlet pipe of the secondary pyrolyzer. The pyrolyzer outlet pipe is communicated with the spray cooling unit. The spray cooling unit has an air outlet end, and the air outlet end is communicated with the harmless combustion chamber, which is used to guide the non-condensable part of the pyrolysis gas after spraying to the harmless combustion chamber to generate high-temperature flue gas. The high-temperature flue gas generated by the harmless combustion chamber provides heat sources for the secondary pyrolyzer and the pyrolysis unit in sequence. After the high-temperature flue gas is utilized, it is cooled down and then guided to the tail gas treatment unit.

[0018] As a preferred solution, control valves for closing the pyrolyzer inlet pipe and the pyrolyzer outlet pipe are provided on both the pyrolyzer inlet pipe and the pyrolyzer outlet pipe. When the pyrolysis gas does not require secondary pyrolysis treatment, the control valves are closed, and the pyrolysis gas that has passed through high-temperature dust removal directly enters the spray cooling unit.

[0019] In summary, by improving the settling chamber of the harmless combustion chamber, the present invention enables it to have the function of performing secondary high-temperature pyrolysis on the pyrolysis gas, fully utilizes the heat of the high-temperature flue gas, reduces the temperature adjustment air distribution amount at the same time, and enhances the dust settling ability of the settling chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the harmless combustion chamber of the present invention; Figure 2 It is a schematic structural diagram of the upper part of the settling chamber of the present invention; Figure 3 It is a schematic structural diagram of the pyrolyzer support platform and the pyrolyzer fixing bracket of the present invention; Figure 4 It is a schematic layout diagram of the heat treatment system of the present invention.

[0021] In the figure: 10, harmless combustion chamber; 11, combustion chamber; 12, sedimentation chamber; 13, high-temperature flue gas outlet; 14, air mixing port; 15, secondary pyrolyzer; 151, pyrolyzer inlet pipe; 152, pyrolyzer outlet pipe; 153, pyrolyzer support platform; 1531, support platform bracket; 154, pyrolyzer fixing bracket; 155, pyrolyzer access port; 156, access port sealing cover; 157, control valve; 16, annular flue gas channel; 20, combustion chamber cooling air configuration unit; 21, heat exchanger; 30, pyrolysis unit; 40, pyrolysis gas dust removal unit; 50, spray cooling unit; 60, tail gas treatment unit. Embodiment Example

[0022] As Figure 1 shown, the harmless combustion chamber described in the present application is an L-shaped combustion chamber, including two main components: a combustion chamber 11 and a sedimentation chamber 12. The function of the combustion chamber 11 is to provide a combustion space for the pyrolysis gas or non-condensable gas generated by heat treatment and generate high-temperature flue gas. The sedimentation chamber 12 is located at one end of the combustion chamber 11, and its main function is to remove dust from the high-temperature flue gas. A dust cleaning port is provided at the bottom, which is prior art.

[0023] As Figure 2 shown, the present application mainly improves the upper part of the sedimentation chamber 12. A secondary pyrolyzer 15 is provided in the upper part of the sedimentation chamber 12, which is filled with a catalyst and used for secondary pyrolysis of the pyrolysis gas, cracking the long-chain compounds generated by pyrolysis of materials such as waste plastics or waste rubbers into short-chain molecules to improve the quality of the pyrolysis gas and prevent the long-chain compounds from blocking the pipeline when cooled. If only the heating time of the pyrolysis gas needs to be extended, the secondary pyrolyzer 15 does not need to be filled with a catalyst, and a tortuous pipeline can be provided inside the secondary pyrolyzer 15. The filling form of the catalyst or the setting form of the tortuous pipeline is prior art and will not be elaborated.

[0024] The secondary pyrolyzer 15 has a cylindrical outer shell, the diameter of the cylindrical outer shell is 1 / 2 of the diameter of the sedimentation chamber 12, and the bottom of the secondary pyrolyzer 15 extends to 1 / 2 of the height of the sedimentation chamber 12. The diameter of the sedimentation chamber 12 can be appropriately increased or decreased, preferably not more than 2 / 3 of the diameter of the sedimentation chamber. An annular flue gas channel 16 for the high-temperature flue gas to pass through is left between the outer wall of the secondary pyrolyzer 15 and the inner wall of the sedimentation chamber 12. When the diameter of the sedimentation chamber 12 increases, the thickness of the annular flue gas channel 16 will be correspondingly reduced. The secondary pyrolyzer 15 has a pyrolyzer inlet pipe 151 and a pyrolyzer outlet pipe 152, which are respectively used to introduce or export the pyrolysis gas.

[0025] Inside the sedimentation chamber 12, there is a pyrolyzer support platform 153 for supporting the secondary pyrolyzer 15 and a pyrolyzer fixing bracket 154 for limiting the secondary pyrolyzer 15. The structures of both are as Figure 3As shown, the surface of the cracker support platform 153 is covered with through holes for the passage of high-temperature flue gas. The obstruction of the cracker support platform 153 helps to reduce the dust content of the heating flue gas. The cracker fixing bracket 154 is arranged between the side wall of the secondary cracker 15 and the inner wall of the sedimentation chamber 12, and it has a fixing ring adapted to the cylindrical outer shell of the secondary cracker 15. Inside the sedimentation chamber 12, there is also a support platform bracket 1531 fixed to the inner wall of the sedimentation chamber 12, and the cracker support platform 153 is placed on the support platform bracket 1531.

[0026] The sedimentation chamber 12 has two air mixing ports 14 for reducing the temperature of the high-temperature flue gas to the required temperature range. One air mixing port 14 is located at the bottom of the cracker support platform 151, and the other air mixing port 14 is located at the high-temperature flue gas outlet 13. The high-temperature flue gas outlet 13 is located at the upper part of the sedimentation chamber 12 for discharging the high-temperature flue gas from the sedimentation chamber 12. After the temperature of the high-temperature flue gas is adjusted by the air mixing port 14 at the high-temperature flue gas outlet 13, the temperature of the high-temperature flue gas drops to the temperature required for the pyrolysis of the material.

[0027] At the top of the sedimentation chamber 12, there is a cracker access port 155 and an access port sealing cover 156 for sealing the cracker access port 155.

[0028] This harmless combustion chamber is suitable for the pyrolysis system of materials such as waste tires, waste plastics, and biomass. Embodiment

[0029] As Figure 4 shown, Embodiment 2 is a heat treatment system containing the harmless combustion chamber described in Embodiment 1. This system includes a harmless combustion chamber 10, a combustion chamber cooling air configuration unit 20, a pyrolysis unit 30, a pyrolysis gas dust removal unit 40, a spray cooling unit 50, and a tail gas treatment unit 60.

[0030] The combustion chamber cooling air configuration unit 20 is divided into two independent branches and is respectively connected to the air mixing ports 14 above and below the secondary cracker 15, and the intake air volume of each air mixing port 14 is controlled separately.

[0031] The pyrolysis gas derived from the pyrolysis unit 30 is first subjected to high-temperature dust removal by the pyrolysis gas dust removal unit 40. The pyrolysis gas dust removal unit 40 has an air outlet end, and its air outlet end is connected to the cracker inlet pipe 151 of the secondary cracker 15. The pyrolysis gas after high-temperature dust removal enters the secondary cracker 15 for secondary pyrolysis.

[0032] The pyrolysis gas outlet pipe 152 of the secondary pyrolyzer 15 is communicated with the spray cooling unit 50. The spray cooling unit 50 has an air outlet end, and its air outlet end is communicated with the harmless combustion chamber 10, and is used for guiding the non-condensable part of the pyrolysis gas after spraying to the harmless combustion chamber 10 for combustion, so as to generate high-temperature flue gas. The high-temperature flue gas generated by the harmless combustion chamber 10 provides heat sources for the secondary pyrolyzer 15 and the pyrolysis unit 30 in sequence. After the high-temperature flue gas is utilized, its temperature is reduced, and then it is guided to the tail gas treatment unit 60.

[0033] Control valves 157 for closing the pyrolysis gas inlet pipe 151 and the pyrolysis gas outlet pipe 152 are provided on both the pyrolysis gas inlet pipe 151 and the pyrolysis gas outlet pipe 152. If the pyrolysis gas does not need to be secondarily pyrolyzed, the control valve 157 is closed.

Claims

1. Harmless combustion chamber, comprising a combustion chamber (11) that provides a combustion space for the pyrolysis gas or non-condensable gas generated by heat treatment and generates high-temperature flue gas; a sedimentation chamber (12) located at one end of the combustion chamber (11) for dust removal of the high-temperature flue gas; a high-temperature flue gas outlet (13) located at the upper part of the sedimentation chamber (12) for discharging the high-temperature flue gas from the sedimentation chamber (12); an air mixing port (14) for mixing air into the high-temperature flue gas to reduce the temperature of the high-temperature flue gas to the required heat treatment temperature; characterized in that: it further comprises a secondary pyrolyzer (15) located in the sedimentation chamber (12), having a pyrolyzer inlet pipe (151) and a pyrolyzer outlet pipe (152); an annular flue gas passage (16) for the high-temperature flue gas to pass through is left between the outer wall of the secondary pyrolyzer (15) and the inner wall of the sedimentation chamber (12); air mixing ports (14) are provided both above and below the secondary pyrolyzer (15).

2. The harmless combustion chamber according to claim 1, characterized in that: the secondary pyrolyzer (15) has a cylindrical outer shell, and the diameter of the cylindrical outer shell is not greater than 2 / 3 of the diameter of the sedimentation chamber (12).

3. The harmless combustion chamber according to claim 1 or 2, characterized in that: the bottom of the secondary pyrolyzer (15) extends at most to 1 / 2 of the height of the sedimentation chamber (12).

4. The harmless combustion chamber according to claim 1, characterized in that: a catalyst is filled inside the secondary pyrolyzer (15).

5. The harmless combustion chamber according to claim 1, characterized in that: it further comprises a pyrolyzer support platform (153) located in the sedimentation chamber (12), the surface of which is covered with through holes for the high-temperature flue gas to pass through, and the air mixing port (14) below the secondary pyrolyzer (15) is located at the bottom of the pyrolyzer support platform (151).

6. The harmless combustion chamber according to claim 1, characterized in that: it further comprises a pyrolyzer fixing bracket (154) arranged between the side wall of the secondary pyrolyzer (15) and the inner wall of the sedimentation chamber (12) for limiting the secondary pyrolyzer (15).

7. The harmless combustion chamber according to claim 1, characterized in that: it further comprises a pyrolyzer access port (155) opened at the top of the sedimentation chamber (12); an access port sealing cover (156) for sealing the pyrolyzer access port (155).

8. A heat treatment system comprising the harmless combustion chamber according to claim 1.

9. The heat treatment system according to claim 8, comprising a harmless combustion chamber (10), a combustion chamber cooling air configuration unit (20), a pyrolysis unit (30), a pyrolysis gas dust removal unit (40), a spray cooling unit (50), and a tail gas treatment unit (60), characterized in that: the combustion chamber cooling air configuration unit (20) is divided into 2 independent branches and respectively communicates with the air mixing ports (14) above and below the secondary pyrolyzer (15); the pyrolysis gas dust removal unit (40) has an air outlet end, the air outlet end communicates with the pyrolyzer inlet pipe (151) of the secondary pyrolyzer (15), and the pyrolyzer outlet pipe (152) communicates with the spray cooling unit (50); The spray cooling unit (50) has an air outlet end, which is communicated with the harmless combustion chamber (10) and is used to guide the non-condensable part of the pyrolysis gas after spraying to the harmless combustion chamber (10) to generate high-temperature flue gas. The high-temperature flue gas generated by the harmless combustion chamber (10) successively provides heat sources for the secondary cracker (15) and the pyrolysis unit (30). After the high-temperature flue gas is utilized, its temperature is reduced, and then it is guided to the tail gas treatment unit (60).

10. The heat treatment system according to claim 8 or 9, characterized in that: Control valves (157) for closing the cracker inlet pipe (151) and the cracker outlet pipe (152) are provided on both the cracker inlet pipe (151) and the cracker outlet pipe (152).

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