Tail gas waste heat recovery white smoke elimination device based on asphalt mixing station
The exhaust gas of the asphalt mixing station was treated by two-stage heat exchange and cyclone dehumidifiers, and the problem of water vapor condensation into white smoke in the exhaust gas was solved, flue gas drying and waste heat recovery were achieved, and pollutant emissions and energy consumption were reduced.
Patent Information
- Application Number
- CN202422092784.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-08-27
AI Technical Summary
Water vapor in the exhaust gas of the asphalt mixing station condenses into white smoke, resulting in an increase in pollutant emissions, making it difficult for the existing technology to effectively treat and recover waste heat.
A combination device of two-stage heat exchanger and cyclone dehumidifier is used to reduce the flue gas humidity through the two-stage heat exchange and dehumidification process, and the flue gas is equipped with heat to increase the emission temperature, eliminate white smoke and recover waste heat.
It effectively reduces pollutant emissions, realizes the drying of flue gas and the reuse of waste heat, saves energy costs, and treats wastewater in an environmentally friendly manner.
Smart Images
Figure CN223090687U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of waste heat recovery equipment, in particular to a tail gas waste heat recovery and whitening elimination device based on an asphalt mixing plant. Background Art
[0002] When the drying cylinder of an asphalt mixture mixing plant heats the stone materials, the stone materials usually need to be heated to 200°C, and the discharged flue gas is generally at 90 - 110°C. Since the stone materials contain a certain amount of moisture, when the temperature is relatively low, when the tail gas is discharged into the atmosphere after dust removal, the water vapor in the tail gas condenses into small water droplets, forming a fog-like water vapor at the outlet of the exhaust pipe, which is called white smoke.
[0003] For the tail gas of the asphalt mixing plant, it is necessary to reduce the humidity in the flue gas, reduce pollutant emissions, and make the flue gas dry and clean. For this problem, it is urgent to develop a tail gas waste heat recovery and whitening elimination device based on an asphalt mixing plant to treat the tail gas of the asphalt mixing plant and recycle the waste heat again. Content of the Utility Model
[0004] The applicant of the present utility model provides a tail gas waste heat recovery and whitening elimination device based on an asphalt mixing plant aiming at the above-mentioned shortcomings in the existing production technology, so as to be able to collect and reuse the waste heat of the flue gas part of the tail gas of the asphalt mixing plant, which is more energy-saving.
[0005] The technical solution adopted by the present utility model is as follows: A tail gas waste heat recovery and whitening elimination device based on an asphalt mixing plant. The flue gas generated when the asphalt mixing plant heats the stone materials is introduced into the first heat exchanger through a pipeline. The flue gas undergoes a first-stage heat exchange in the first heat exchanger and then is sent into the second heat exchanger through a pipeline for a second-stage heat exchange in the second heat exchanger; after the flue gas completes the second-stage heat exchange in the second heat exchanger and cools down, it is sent from the second heat exchanger to the cyclone dehumidifier through a pipeline; the smoke exhaust port of the cyclone dehumidifier is communicated with the low-temperature medium inlet of the first heat exchanger through a pipeline and is used to cool down the flue gas of the asphalt mixing plant introduced into the first heat exchanger; the low-temperature medium outlet of the first heat exchanger is connected to the air inlet of the induced draft fan of the mixing equipment through a pipeline, and the air outlet of the induced draft fan of the mixing equipment is connected to the exhaust pipe of the mixing equipment. The treated flue gas is discharged from the exhaust pipe of the mixing equipment to the atmosphere or the hot end.
[0006] As a further improvement of the above technical solution:
[0007] Preferably, a one-way drain valve for draining water is provided at the bottom of each of the first heat exchanger, the second heat exchanger, and the cyclone dehumidifier, and each one-way drain valve sends the waste water into the sewage treatment plant through a sewage collection pipeline.
[0008] Preferably, the first heat exchanger and the second heat exchanger are heat exchanger devices with the same structure.
[0009] Preferably, the structure of the first heat exchanger is as follows: it includes a heat exchange cavity, with a high-temperature medium inlet provided at the bottom of the heat exchange cavity, a high-temperature medium outlet provided at the top of the heat exchange cavity, a low-temperature medium inlet provided at one side of the heat exchange cavity, and a low-temperature medium outlet provided at the other side of the heat exchange cavity.
[0010] Preferably, the exhaust port of the mixing equipment exhaust stack is connected to the heat-using end through a pipeline; an air switching valve is provided on the pipeline between the mixing equipment exhaust stack and the heat-using end.
[0011] Preferably, an air filter is provided on the pipeline on the side where the low-temperature medium enters the second heat exchanger.
[0012] Preferably, the pipeline on the side where the low-temperature medium is discharged from the second heat exchanger is connected to the air inlet of a ventilator, and the air outlet of the ventilator is connected to the heat-using end through a pipeline.
[0013] The beneficial effects of the present utility model are as follows:
[0014] The structure of the present utility model is compact. There are two-stage heat exchanges during the cooling process of the high-temperature flue gas. The flue gas generated when the asphalt mixing plant heats the stone materials is exchanged heat through the first heat exchanger, and the flue gas after being processed by the first heat exchanger is heat-exchanged again through the second heat exchanger to gradually reduce the flue gas temperature. The whole process is efficient and stable, reducing the humidity in the flue gas, further reducing pollutant emissions, and making the flue gas dry and clean.
[0015] The present utility model also has the following advantages:
[0016] (1) In the present utility model, the flue gas sequentially processed by the first heat exchanger, the second heat exchanger, and the cyclone dehumidifier enters from the low-temperature medium inlet of the first heat exchanger again and is sent to the heat-using end; the low-temperature medium of the second heat exchanger is heated and then sent to the heat-using end from the low-temperature medium outlet of the second heat exchanger. Essentially, the present utility model utilizes the heat carried by the flue gas itself to increase the temperature of the discharged flue gas without adding additional heating equipment, saving costs and effectively eliminating white smoke at the same time.
[0017] (2) In the present utility model, one-way drainage valves for draining water are provided at the bottoms of the first heat exchanger, the second heat exchanger, and the cyclone dehumidifier. Each one-way drainage valve sends the waste water into the sewage treatment plant through a sewage collection pipeline, which is more environmentally friendly.
[0018] (3) In the present utility model, the flue gas processed by the second heat exchanger is sent into the cyclone dehumidifier to further remove the excess moisture in the flue gas and make the flue gas drier. Description of the Drawings
[0019] Figure 1 It is a schematic diagram of the overall layout structure of the present utility model.
[0020] Figure 2 This is a schematic structural diagram of the first heat exchanger in the present utility model.
[0021] Among them: 1. The first heat exchanger; 2. The one-way drain valve; 3. The second heat exchanger; 4. The air filter; 5. The cyclone dehumidifier; 6. The induced draft fan of the mixing equipment; 7. The exhaust stack of the mixing equipment; 8. The ventilator; 9. The air switching valve; 10. The sewage collection pipeline; 11. The heat utilization end.
[0022] 101. High-temperature medium inlet; 102. High-temperature medium outlet; 103. Low-temperature medium inlet; 104. Low-temperature medium outlet; 105. Heat exchange cavity. Specific embodiments
[0023] The following combines with the attached drawings to illustrate the specific embodiments of the present utility model.
[0024] As Figures 1 to 2 shown, for the tail gas waste heat recovery and white smoke elimination device based on the asphalt mixing plant in this embodiment, the flue gas generated when the asphalt mixing plant heats the stone materials is introduced into the first heat exchanger 1 through a pipeline. After the first-stage heat exchange in the first heat exchanger 1, the flue gas is sent into the second heat exchanger 3 through a pipeline and undergoes the second-stage heat exchange in the second heat exchanger 3; after the flue gas completes the second-stage heat exchange in the second heat exchanger 3 and cools down, it is sent from the second heat exchanger 3 through a pipeline into the cyclone dehumidifier 5; the smoke exhaust port of the cyclone dehumidifier 5 is communicated with the low-temperature medium inlet 103 of the first heat exchanger 1 through a pipeline and is used to cool down the flue gas of the asphalt mixing plant introduced into the first heat exchanger 1; the low-temperature medium outlet 104 of the first heat exchanger 1 is connected to the air inlet of the induced draft fan 6 of the mixing equipment through a pipeline, and the air outlet of the induced draft fan 6 of the mixing equipment is communicated with the exhaust stack 7 of the mixing equipment. The treated flue gas is discharged from the exhaust stack 7 of the mixing equipment to the atmosphere or the heat utilization end 11.
[0025] In this embodiment, one-way drain valves 2 for draining water are provided at the bottoms of the first heat exchanger 1, the second heat exchanger 3, and the cyclone dehumidifier 5, and each one-way drain valve 2 sends the waste water into the sewage treatment plant through the sewage collection pipeline 10.
[0026] In this embodiment, the first heat exchanger 1 and the second heat exchanger 3 are heat exchanger devices with the same structure.
[0027] In this embodiment, the structure of the first heat exchanger 1 is: including a heat exchange cavity 105, a high-temperature medium inlet 101 is provided at the bottom of the heat exchange cavity 105, a high-temperature medium outlet 102 is provided at the top of the heat exchange cavity 105, a low-temperature medium inlet 103 is provided on one side of the heat exchange cavity 105, and a low-temperature medium outlet 104 is provided on the other side of the heat exchange cavity 105.
[0028] In this embodiment, the exhaust port of the mixing equipment exhaust stack 7 is connected to the heat-using end 11 through a pipeline; an air switching valve 9 is arranged on the pipeline between the mixing equipment exhaust stack 7 and the heat-using end 11.
[0029] In this embodiment, an air filter 4 is arranged on the pipeline on the inlet side of the low-temperature medium of the second heat exchanger 3.
[0030] In this embodiment, the pipeline on the discharge side of the low-temperature medium of the second heat exchanger 3 is connected to the air inlet of the ventilator 8, and the air outlet of the ventilator 8 is connected to the heat-using end 11 through a pipeline.
[0031] In this embodiment, exemplarily, the treated hot gas can be directly discharged into the atmosphere through the mixing equipment exhaust stack 7.
[0032] In this embodiment, the working process flow of the present utility model for high-temperature flue gas is as follows:
[0033] Step 1: When the drying drum of the asphalt mixture mixing plant heats the stones, high-temperature flue gas at 90 - 110 °C is generated. After being dust-removed first, the high-temperature flue gas is sent into the first heat exchanger 1.
[0034] Step 2: The high-temperature flue gas at 90 - 110 °C exchanges heat in the first heat exchanger 1. After heat exchange, it is discharged from the first heat exchanger 1. At this time, the temperature is about 45 °C - 65 °C. At the same time, due to the temperature reduction, part of the moisture is precipitated and sent into the sewage collection pipeline 10 through the one-way drainage valve 2 at the bottom of the first heat exchanger 1.
[0035] Step 3: The flue gas at 45 °C - 65 °C is sent into the second heat exchanger 3. After heat exchange in the second heat exchanger 3, it is discharged from the second heat exchanger 3. At this time, the temperature is 20 °C. At the same time, due to the temperature reduction, part of the moisture is precipitated and sent into the sewage collection pipeline 10 through the one-way drainage valve 2 at the bottom of the second heat exchanger 3.
[0036] Step 4: The 20 °C water-containing flue gas discharged from the second heat exchanger 3 is sent into the cyclone dehumidifier 5 to further remove the excess moisture. The moisture in the cyclone dehumidifier 5 is sent into the sewage collection pipeline 10 through the one-way drainage valve 2 at the bottom.
[0037] Step 5: The flue gas from which the excess moisture has been removed after being treated by the cyclone dehumidifier 5 is sent into the low-temperature medium inlet 103 of the first heat exchanger 1. After heat exchange in the first heat exchanger 1, a humidity-unsaturated flue gas with a discharge temperature of 65 °C - 85 °C is formed.
[0038] Step 6: The humidity-unsaturated flue gas at 65 °C - 85 °C is sent into the mixing equipment exhaust stack 7 through the mixing equipment induced draft fan 6 and forms a state without white smoke, meeting the standard for discharge.
[0039] In this embodiment, in the present utility model, the normal temperature air is 0 to 10 °C. After the normal temperature air passes through the air filter 4 to remove impurities, it enters the second heat exchanger 3. After heat exchange in the second heat exchanger 3, the discharged air at 30 °C to 55 °C is formed. The discharged air at 30 °C to 55 °C is adjusted in flow rate by the ventilator 8 and sent into the heat-using end 11.
[0040] In this embodiment, exemplarily, the heat-using end 11 can be that the treated hot gas is sent into the air inlet of the drying cylinder burner to achieve a more energy-saving effect; or it can be that the treated hot air is sent into the room to achieve the effect of adjusting the indoor temperature.
[0041] In this embodiment, specifically, the ventilator 8 can adopt a ventilator with variable frequency control for adjusting the flow rate.
[0042] The structure of the present utility model is reasonable, and the heat exchange process is stable. The high-temperature flue gas generated when the asphalt mixing plant heats the stone materials passes through the first heat exchanger 1, the second heat exchanger 3, and the cyclone dehumidifier 5 in sequence. The treated flue gas enters again from the low-temperature medium inlet 103 of the first heat exchanger 1 and is sent to the heat-using end 11. The low-temperature medium of the second heat exchanger is heated up after heat exchange and sent to the heat-using end. In essence, the heat carried by the flue gas itself is utilized to increase the temperature of the discharged flue gas without the need to additionally increase heating equipment, saving costs and effectively eliminating white smoke at the same time.
[0043] The above description is an explanation of the present utility model, not a limitation thereof. For the scope defined by the present utility model, refer to the claims. Any form of modification can be made within the protection scope of the present utility model.
Claims
1. An exhaust gas waste heat recovery and white smoke elimination device based on an asphalt mixing plant, characterized in that: asphalt The flue gas generated when the mixing plant heats the stone materials is introduced into the first heat exchanger (1) through a pipeline. The flue gas undergoes primary heat exchange in the first heat exchanger (1) and then is sent into the second heat exchanger (3) through a pipeline for secondary heat exchange in the second heat exchanger (3). The flue gas that has completed secondary heat exchange in the second heat exchanger (3) is cooled and then sent from the second heat exchanger (3) into the cyclone dehumidifier (5) through a pipeline. The smoke exhaust port of the cyclone dehumidifier (5) is communicated with the low-temperature medium inlet (103) of the first heat exchanger (1) through a pipeline and is used to cool the flue gas of the asphalt mixing plant introduced into the first heat exchanger (1). The low-temperature medium outlet (104) of the first heat exchanger (1) is connected to the air inlet of the mixing equipment induced draft fan (6) through a pipeline. The air outlet of the mixing equipment induced draft fan (6) is connected to the mixing equipment exhaust stack (7). The treated flue gas is discharged from the mixing equipment exhaust stack (7) to the atmosphere or the heat end (11).
2. The exhaust gas waste heat recovery and white smoke elimination device based on an asphalt mixing plant according to claim 1, wherein: One-way drain valves (2) for draining water are provided at the bottoms of the first heat exchanger (1), the second heat exchanger (3), and the cyclone dehumidifier (5). Each one-way drain valve (2) sends the waste water into the sewage treatment plant through a sewage collection pipeline (10).
3. The waste heat recovery and white smoke elimination device based on an asphalt mixing plant according to claim 1, wherein: The first heat exchanger (1) and the second heat exchanger (3) are heat exchanger devices with the same structure.
4. The waste heat recovery and white-out elimination device for tail gas based on an asphalt mixing plant according to claim 3, wherein: The structure of the first heat exchanger (1) is as follows: it includes a heat exchange cavity (105). A high-temperature medium inlet (101) is provided at the bottom of the heat exchange cavity (105), a high-temperature medium outlet (102) is provided at the top of the heat exchange cavity (105), a low-temperature medium inlet (103) is provided on one side of the heat exchange cavity (105), and a low-temperature medium outlet (104) is provided on the other side of the heat exchange cavity (105).
5. The waste heat recovery and white-out elimination device for tail gas based on an asphalt mixing plant according to claim 1, wherein: The exhaust port of the mixing equipment exhaust stack (7) is connected to the heat end (11) through a pipeline. An air switching valve (9) is provided on the pipeline between the mixing equipment exhaust stack (7) and the heat end (11).
6. The waste heat recovery and white smoke elimination device based on an asphalt mixing plant according to claim 1, characterized in that: An air filter (4) is provided on the pipeline on the side where the low-temperature medium enters the second heat exchanger (3).
7. The waste heat recovery and white smoke elimination device based on an asphalt mixing plant according to claim 1, wherein: The pipeline on the side where the low-temperature medium is discharged from the second heat exchanger (3) is connected to the air inlet of the ventilator (8). The air outlet of the ventilator (8) is connected to the heat end (11) through a pipeline.