A flue gas treatment method for heating by adding a large proportion of asphalt mixture

Abstract

The present invention discloses a flue gas treatment method for heating an asphalt mixture with a large proportion of added materials, and belongs to the technical field of asphalt production equipment. The flue gas treatment method is based on an asphalt mixture flue gas treatment system. When producing recycled materials, the fire is increased by a burner to heat the recycled materials added in a large proportion. The flue gas generated by the heating furnace is introduced into the original drying inner cylinder and the heating chamber through flue gas pipelines 1 and 2 respectively to heat the original materials, and finally discharged through a bag filter and a smoke exhaust device to form an external circulation gas; the flue gas generated by the heating furnace enters the regeneration drying drum through a flue gas pipeline 3, and the hot flue gas generated by the combination of the recycled materials and the original materials is introduced into the heating furnace through an induced draft fan 2 for secondary combustion to form an internal circulation gas. Through the combination of the internal and external circulation gases, the sum of the external circulation gas is greater than the sum of the regeneration flue gas and the gas generated by the burner, thereby preventing fine materials from being sucked away by the bag filter.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt production equipment, and more specifically to a flue gas treatment method for heating by adding a large proportion of asphalt mixture. Background Art

[0002] Asphalt mixture thermal regeneration technology is a technology for recycling waste asphalt mixture.

[0003] The main process flow is: first, the heated hot recycled material is metered and directly sent into the main mixing tank of the primary machine, then a certain amount of regeneration agent is sprayed to allow the recycled material and the regeneration agent to be evenly mixed in the mixing tank of the primary machine first, and finally new aggregates, new asphalt, stone powder and other materials are added into the same main mixing tank and mixed evenly.

[0004] The traditional method is to let the regenerated exhaust gas enter the original drying drum for combustion. However, due to the large amount of regenerated flue gas entering, the air flow in the original drying drum becomes chaotic. When the original output is small and a large proportion of recycled materials are added, the original fine materials will be sucked away by the bag dust collector, affecting the grading of the finished material. Another traditional method is to directly introduce the regenerated exhaust gas into the inlet of the bag dust collector, mix the regenerated flue gas with the original flue gas, and finally discharge it through the bag dust collector. The disadvantage of this method is that the sulfur dioxide, nitrogen oxides, and benzo(a)pyrene in the regenerated exhaust gas do not undergo secondary combustion, and direct emission will pollute the environment. Summary of the invention

[0005] The present invention provides a flue gas treatment method for heating an asphalt mixture by adding a large proportion of recycled materials to solve the problems that when the original output is small, a large proportion of recycled materials needs to be added, the original fine materials will be sucked away by the bag dust collector, thereby affecting the grading of the finished materials, and there is pollution from harmful gases in the regenerated tail gas.

[0006] The present invention adopts the following technical solution:

[0007] A flue gas treatment method for heating by adding a large proportion of asphalt mixture is based on an asphalt mixture flue gas treatment system. The asphalt mixture flue gas treatment system includes a burner, a heating furnace, a native double-layer drying drum, a regeneration drying drum and a bag dust collector. The native double-layer drying drum includes a native drying inner cylinder and a native drying outer cylinder. The native drying outer cylinder is coaxially arranged outside the native drying inner cylinder and a heating chamber is formed between the two. The burner is installed at one end of the heating furnace, and the other end of the heating furnace is respectively connected to the native drying inner cylinder through a flue gas pipeline 1, connected to the heating chamber through a flue gas pipeline 2, and connected to the regeneration drying drum through a flue gas pipeline 3. The exhaust end of the native drying inner cylinder and the exhaust end of the heating chamber are respectively connected to the bag dust collector, and the exhaust end of the regeneration drying drum is connected to the heating furnace; the treatment method of the asphalt mixture flue gas treatment system includes:

[0008] (1) When producing raw materials, the burner is turned on at a low fire to heat in the heating furnace, and the generated flue gas is sent to the raw drying inner cylinder to heat the aggregate, and finally the dust is filtered by the bag filter before being discharged;

[0009] (2) When producing recycled materials, increase the firepower of the burner, and the flue gas generated by heating in the heating furnace is discharged in three ways: the first way is to introduce the flue gas into the original drying inner cylinder to heat the original aggregate, and then discharge it through the bag dust collector; the second way is to introduce the flue gas into the heating chamber to heat the original aggregate by thermal radiation, and then discharge it through the bag dust collector; the third way is to introduce the flue gas into the regeneration drying drum to heat the recycled material, and the hot flue gas generated at the tail is introduced into the furnace secondary burner to carry out secondary combustion of the harmful gases in the regeneration tail gas.

[0010] Furthermore, a first electric valve is installed on the first flue gas pipeline, a second electric valve is installed on the second flue gas pipeline, and a third electric valve is installed on the third flue gas pipeline, and the first electric valve, the second electric valve and the third electric valve can all be adjusted in size.

[0011] Furthermore, (1) when producing virgin materials, the first electric valve is opened, and the second electric valve and the third electric valve are closed; the generated smoke is introduced into the inner drum of the virgin drying and discharged through the bag dust collector; (2) when producing recycled materials, the first electric valve, the second electric valve, and the third electric valve are opened respectively, and the generated smoke is discharged through the three routes.

[0012] Furthermore, the original drying inner cylinder is connected to the bag dust collector through the smoke exhaust pipe 1, the heating chamber is connected to the bag dust collector through the smoke exhaust pipe 2, and the bag dust collector is connected to the smoke exhaust device.

[0013] Furthermore, the smoke exhaust device includes an induced draft fan and a chimney, and the smoke enters the chimney through the induced draft fan and is discharged.

[0014] Furthermore, the exhaust end of the regeneration drying drum is connected to a fan duct, the other end of the fan duct is connected to the heating furnace, and a second induced draft fan is provided on the fan duct.

[0015] Furthermore, it also includes a PLC control system, which is communicatively connected with the first electric valve, the second electric valve, the third electric valve, the first induced draft fan, and the second induced draft fan.

[0016] From the above description of the structure of the present invention, it can be seen that compared with the prior art, the present invention has the following advantages:

[0017] The present invention is based on an asphalt mixture flue gas treatment system. When producing recycled materials, the fire is increased through a burner to heat the recycled materials added in a large proportion. The flue gas generated in the heating furnace is introduced into the original drying inner cylinder and the heating chamber through a flue gas pipeline 1 and a flue gas pipeline 2 respectively to heat the original materials, and is finally discharged through a bag filter and a smoke exhaust device to form an external circulation gas; the flue gas generated in the heating furnace enters the regeneration drying drum through a flue gas pipeline 3, and the hot flue gas generated by the combination of the recycled materials and the original materials is introduced into the heating furnace through an induced draft fan 2 for secondary combustion to form an internal circulation gas, and sulfur dioxide, nitrogen oxides, and benzo(a)pyrene in the regeneration flue gas are burned and treated; at the same time, the flue gas content in the regeneration drying drum is reduced to cool the heating furnace. Through the combination of internal and external circulating gases, the sum of the externally circulating gases is greater than the sum of the regenerated flue gas and the gas produced by the burner, ensuring the gas balance while preventing the original fine materials in the original double-layer drying drum from being sucked away by the bag filter due to excessive gas volume, thereby improving the quality of the finished asphalt mixture and ensuring production quality. In addition, through the secondary combustion of the regenerated exhaust gas, it is ensured that the harmful gases are fully burned, while improving production efficiency, reducing equipment failure rate, saving energy and reducing emissions, and saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0019] The specific implementation of the present invention is described below with reference to the accompanying drawings. In order to fully understand the present invention, many details will be described below, but for those skilled in the art, the present invention can be implemented without these details. For well-known components, methods and processes, no detailed description will be given below.

[0020] Reference Figure 1 A flue gas treatment method for heating with large proportion of asphalt mixture is based on the asphalt mixture flue gas treatment system. The asphalt mixture flue gas treatment system includes a burner 10, a heating furnace 11, a native double-layer drying drum 12, a regeneration drying drum 13 and a bag filter 14. The burner 10 is installed at one end of the heating furnace 11. The native double-layer drying drum 12 includes a native drying inner cylinder 121 and a native drying outer cylinder 122. The native drying outer cylinder 122 is coaxially arranged outside the native drying inner cylinder 121 and a heating chamber 123 is formed between the two. The other end of the heating furnace 11 is respectively connected with a flue gas pipeline 15, a flue gas pipeline 2 16 and a flue gas pipeline 3 17.

[0021] The above-mentioned flue gas pipeline 15 is connected to the original drying inner cylinder 121, and the original drying inner cylinder 121 is connected to the bag dust collector 14 through the exhaust pipe 18, and the bag dust collector 14 is connected to the exhaust device 19. The above-mentioned flue gas pipeline 2 16 is connected to the heating chamber 123, and the heating chamber 123 is connected to the exhaust pipe 2 20 connected to the bag dust collector 14, and the bag dust collector 14 is connected to the exhaust device 19. The exhaust device 19 includes an induced draft fan 191 and a chimney 192. The dust-removed flue gas then passes through the induced draft fan 191 and is discharged into the atmosphere through the chimney 192. The induced draft fan 191 can adjust the air volume according to the production volume of the original material / large proportion of recycled material.

[0022] The above-mentioned flue gas pipeline three 17 is connected to the regeneration drying drum 13, the flue gas discharge end of the regeneration drying drum 13 is connected to the fan duct 21, the other end of the fan duct 21 is connected to the heating furnace 11, and the fan duct 21 is provided with an induced draft fan 22, which can adjust the air volume according to the production volume of large-scale added recycled materials.

[0023] Continue to refer to Figure 1 A first electric valve 23 is installed on the flue gas pipeline 15, a second electric valve 24 is installed on the flue gas pipeline 16, and a third electric valve 25 is installed on the flue gas pipeline 17. The first electric valve 23, the second electric valve 24, and the third electric valve 25 can all be adjusted in size.

[0024] The above-mentioned asphalt mixture smoke treatment system also includes a PLC control system, which is communicatively connected with the first electric valve 23, the second electric valve 24, the third electric valve 25, the induced draft fan 191, and the induced draft fan 22.

[0025] Continue to refer to Figure 1 The above-mentioned flue gas treatment method for heating by adding a large proportion of asphalt mixture includes:

[0026] When raw aggregate is produced, the burner 10 starts with a low fire to heat in the heating furnace 11. The first electric valve 23 of the flue gas pipeline 15 is opened, the second electric valve 24 on the flue gas pipeline 2 16 and the third electric valve 25 on the flue gas pipeline 3 17 are closed through the PLC control system, and the generated flue gas is sent to the raw drying inner cylinder 121 to heat the raw aggregate. The first electric valve 23 can be controlled to increase or decrease according to the amount of hot flue gas generated. Finally, the dust is filtered by the bag filter 14 and then passes through the induced draft fan 191 and is discharged into the atmosphere through the chimney 192.

[0027] When producing recycled materials, increase the firepower of the burner 10, open the first electric valve 23 of the flue gas pipeline 15, the second electric valve 24 on the flue gas pipeline 2 16, and the third electric valve 25 on the flue gas pipeline 3 17 one by one through the PLC control system, and adjust the sizes of the first electric valve 23, the second electric valve 24, and the third electric valve 25 according to the amount of hot flue gas generated, so that the flue gas generated by heating in the heating furnace 11 is discharged in three ways:

[0028] The first route: When producing recycled materials, a large proportion of recycled materials are added. First, the burner 10 is heated to heat the recycled materials added in a large proportion. The hot flue gas generated by the heating furnace 11 is connected to the original drying inner cylinder 121 through the flue gas pipeline 15 to heat the original materials. The flue gas is finally discharged through the exhaust pipe 18, the bag dust collector 14 and the exhaust device 19.

[0029] The second route: when producing recycled materials, a large proportion of recycled materials are added, and the burner 10 is first heated to heat the recycled materials added in a large proportion. The flue gas generated by the heating furnace 11 is connected to the heating chamber 123 through the flue gas pipeline 16, and the original materials are heated by thermal radiation. The flue gas is finally discharged through the exhaust pipe 20, the bag dust collector 14 and the exhaust device 19, which reduces the energy consumption of the burner 10 and extends its service life.

[0030] The third route: when a large proportion of recycled material is added, the burner 10 is first heated to heat the recycled material added in a large proportion, and the flue gas generated by the heating furnace 11 enters the regeneration drying drum 13 through the flue gas pipeline 3 17. The hot flue gas generated by the combination of the recycled material and the original material is introduced into the heating furnace 11 through the induced draft fan 22 for secondary combustion to form an internal circulation gas, and the harmful gas in the regeneration flue gas is burned to make the discharged gas purer and pollution-free; at the same time, the flue gas content in the regeneration drying drum 13 is reduced, the heating furnace 11 is cooled, and the service life of the heating furnace 11 is extended.

[0031] By treating the flue gas in the above-mentioned manner of combining internal and external circulation, the original fine material in the original double-layer drying drum 12 will not be sucked away by the bag dust collector 14 due to excessive gas volume, thereby improving the quality of the finished asphalt mixture; by effectively treating the harmful gases in the hot flue gas generated by the combination of recycled materials and original materials through secondary combustion, the flue gas will not cause pollution to the environment, which is more environmentally friendly and practical.

[0032] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A flue gas treatment method for heating by adding a large proportion of asphalt mixture, characterized in that: Based on the asphalt mixture fume treatment system, the asphalt mixture fume treatment system includes a burner, a heating furnace, a native double-layer drying drum, a regeneration drying drum and a bag dust collector. The native double-layer drying drum includes a native drying inner cylinder and a native drying outer cylinder. The native drying outer cylinder is coaxially arranged outside the native drying inner cylinder and a heating chamber is formed between the two. The burner is installed at one end of the heating furnace, and the other end of the heating furnace is respectively connected to the native drying inner cylinder through a flue gas pipeline 1, connected to the heating chamber through a flue gas pipeline 2, and connected to the regeneration drying drum through a flue gas pipeline 3. The exhaust end of the native drying inner cylinder and the exhaust end of the heating chamber are respectively connected to the bag dust collector, and the exhaust end of the regeneration drying drum is connected to the heating furnace; The treatment method of the asphalt mixture fume treatment system includes: (1) When producing raw materials, the burner is turned on at a low fire to heat in the heating furnace, and the generated flue gas is sent to the raw drying inner cylinder to heat the aggregate, and finally the dust is filtered by the bag filter before being discharged; (2) When producing recycled materials, increase the firepower of the burner, and the flue gas generated by heating in the furnace is discharged in three ways: the first way is to introduce the flue gas into the original drying inner cylinder to heat the original aggregate, and then discharge it through the bag dust collector; The second route introduces the flue gas into the heating chamber, heats the original aggregate by thermal radiation, and then discharges it through the bag filter; the third route introduces the flue gas into the regeneration drying drum to heat the recycled material, and the hot flue gas generated at the tail is introduced into the furnace secondary burner to carry out secondary combustion of the harmful gas in the regeneration tail gas; the flue gas generated in the heating furnace is introduced into the original drying inner cylinder and the heating chamber through the flue gas pipeline 1 and the flue gas pipeline 2 respectively to heat the original material, and finally discharged through the bag filter and the smoke exhaust device to form external circulation gas; the flue gas generated in the heating furnace enters the regeneration drying drum through the flue gas pipeline 3, and the hot flue gas generated by the combination of the recycled material and the original material is introduced into the heating furnace through the induced draft fan 2 for secondary combustion to form internal circulation gas. Through the combination of the internal and external circulation gases, the sum of the external circulation gas is greater than the sum of the regeneration flue gas and the gas generated by the burner, which ensures the gas volume balance while preventing the original fine material in the original double-layer drying drum from being sucked away by the bag filter due to excessive gas volume.

2. The method for treating flue gas by heating a large proportion of asphalt mixture according to claim 1, characterized in that: The first flue gas pipeline is provided with a first electric valve, the second flue gas pipeline is provided with a second electric valve, and the third flue gas pipeline is provided with a third electric valve, and the first electric valve, the second electric valve and the third electric valve can all be adjusted in size.

3. The method for treating flue gas by heating a large proportion of asphalt mixture according to claim 2, characterized in that: (1) When producing virgin materials, the first electric valve is opened, and the second and third electric valves are closed; the generated smoke is introduced into the inner drum of the virgin drying and discharged through the bag dust collector; (2) When producing recycled materials, the first electric valve, the second electric valve, and the third electric valve are opened respectively, and the generated smoke is discharged through the three routes.

4. The method for treating flue gas by heating a large proportion of asphalt mixture according to claim 2, characterized in that: The original drying inner cylinder is connected to the bag dust collector through a smoke exhaust pipe 1, the heating chamber is connected to the bag dust collector through a smoke exhaust pipe 2, and the bag dust collector is connected to a smoke exhaust device.

5. The method for treating flue gas by heating a large proportion of asphalt mixture according to claim 4, characterized in that: The smoke exhaust device comprises an induced draft fan 1 and a chimney, and smoke enters the chimney through the induced draft fan 1 and is discharged.

6. The method for treating flue gas by heating a large proportion of asphalt mixture according to claim 5, characterized in that: The exhaust end of the regeneration drying drum is connected to a fan duct, the other end of the fan duct is connected to the heating furnace, and a second induced draft fan is provided on the fan duct.

7. The method for treating flue gas by heating a large proportion of asphalt mixture according to claim 6, characterized in that: It also includes a PLC control system, which is communicatively connected with the first electric valve, the second electric valve, the third electric valve, the first induced draft fan, and the second induced draft fan.

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