Purification device for synergistically removing VOCs and NOx
By setting up a plate heat exchanger and a front-end denitrification device on the ventilation pipe of the purification device, the problem of difficulty in reducing the exhaust gas temperature and low NOx removal efficiency is solved, and efficient decomposition of exhaust gas and coordinated treatment of NOx is achieved. At the same time, by setting up a water washing purification device at the front of the chimney, the purification standards of exhaust gas are further improved.
Patent Information
- Application Number
- CN202420436170.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-07
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2034-03-07
AI Technical Summary
In the prior art, it is impossible to initially cool the incoming waste gas, which makes it difficult to reduce the temperature of the waste gas, affecting the purification efficiency of the waste gas. At the same time, it is impossible to ensure that the exhausted waste gas is completely purified, which may have an impact on the environment.
A purification device that coordinates the removal of VOCs and NOx is designed. By setting up a plate heat exchanger on the ventilation pipe, the exhaust gas passing into the heat storage chamber is heat exchanged, so that the exhaust gas temperature is reduced, and the energy utilization is synergistically processed through the front-end denitrification device. At the same time, a purification device is installed at the front end of the chimney to wash and purify the purified waste gas, remove odor and further purify the waste gas.
The exhaust gas temperature is reduced through heat exchange, the waste gas decomposition efficiency is improved, and the NOx removal efficiency is improved through energy utilization; water washing and purification effectively removes the odor in the purified waste gas, and improves the purification standard for exhausting waste gas.
Smart Images
Figure CN222605927U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of refining tail gas treatment, and specifically relates to a purification device for collaboratively removing VOCs and NOx. Background Art
[0002] As people's environmental awareness continues to improve and environmental protection needs become more urgent, the country has also put forward more stringent requirements for the tail gas emission standards of traditional refining and chemical enterprises. There will be a large amount of nitrogen oxides (NOx) in the flue gas of refineries, and disorderly emissions will cause acid rain, haze and other air pollution. Volatile organic compounds (VOCs) that are disorderly emitted during the loading, unloading and storage of oil products and chemical materials in refining and chemical enterprises are also the main precursors of photochemical pollution. They will form fine particulate matter and damage the ozone layer, and they are also irritating and toxic.
[0003] At present, the technology for removing NOx from flue gas has been developed to a relatively mature level, and the research on light hydrocarbons as reducing agents in SCR systems has also made initial progress. The thermal storage type organic waste gas incinerator is currently the most energy-saving and effective method for reducing volatile organic compound emissions in the world. This method uses a thermal storage type heat recovery method to recover more than 90% of the heat energy in the high-temperature flue gas, and the exhaust temperature of the flue gas can be reduced to about 180°. When the organic matter in the waste gas to be treated reaches a certain concentration, no additional heat is required during operation, so the operating cost is extremely low. It is estimated that if all organic waste gas in the country is treated with thermal storage type waste gas incinerators, the emission of volatile organic compounds can be reduced by more than 90%, which will significantly improve the air quality.
[0004] When the regenerative organic waste gas incinerator is in stable operation, the destruction and removal rate of VOC is more than 97.5%, which saves more than 87.7% of fuel compared with thermal incinerators of the same processing capacity. The destruction and removal rate of VOC by the regenerative organic waste gas incinerator is 10 to 15 percentage points higher than that of existing incinerators, and the content of unburned hydrocarbons in the flue gas is far lower than the value specified by the national standard: in addition, it saves a lot of energy compared with thermal incinerators.
[0005] Nowadays, the traditional two-chamber RTO process principle is as follows Figure 1As shown, the low-temperature exhaust gas to be treated enters the first heat storage chamber through the induced draft fan. The ceramic heat storage body releases heat and the temperature decreases. The organic waste gas rises to a higher temperature and then enters the oxidation chamber. In the oxidation chamber, the burner burns to supplement heat, so that the exhaust gas rises to the set oxidation temperature (760°), and the organic components in the exhaust gas are decomposed into CO2 and H2O. Since the exhaust gas has been preheated in the heat storage chamber, the amount of external fuel is less. The purified high-temperature exhaust gas leaves the oxidation chamber and enters the first heat storage chamber, releasing heat. After the temperature drops, it is discharged into the air through the chimney by the exhaust fan. The ceramic heat storage body in the second heat storage chamber absorbs heat and "stores" a large amount of heat (for heating the exhaust gas in the next cycle). After one cycle is completed, the air inlet and outlet valves are switched once to change the airflow direction (enter the next cycle). The exhaust gas enters the second heat storage chamber, and the purified gas is discharged from the first heat storage chamber. This process is repeated alternately.
[0006] The above two-chamber RTO process still has the following deficiencies in actual use: From a practical point of view, when the exhaust gas is introduced into the heat storage chamber in the process, since the exhaust gas discharge is usually accompanied by high temperature, the introduced exhaust gas will increase the heat of the ceramic heat storage body in the heat storage chamber, which makes it difficult to lower the exhaust gas temperature, thereby reducing the decomposition of the exhaust gas in the oxidation chamber, thereby affecting the exhaust gas purification efficiency. At the same time, when the purified exhaust gas is discharged, it may have an impact on the environment because it is impossible to accurately and intuitively ensure whether the exhaust gas is completely purified.
[0007] Therefore, a purification device for synergistically removing VOCs and NOx is needed to solve the problems in the prior art of being unable to initially cool the incoming exhaust gas and being unable to ensure that the exhausted exhaust gas is completely purified. Utility Model Content
[0008] The purpose of the utility model is to provide a purification device for collaboratively removing VOCs and NOx to solve the problems raised in the above background technology.
[0009] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a purification device for synergistically removing VOCs and NOx, comprising an air intake pipe and a first fan, a filter is connected between the air intake pipe and the first fan via a flange, the other end of the first fan is fixedly connected to a heat exchanger via a connecting pipe, the other end of the heat exchanger is fixedly connected to a first heat storage chamber and a second heat storage chamber via a connecting pipe, the heat output end of the heat exchanger is fixedly connected to a front-end denitrification device via a pipeline, the tops of the first heat storage chamber and the second heat storage chamber are connected to an incineration chamber, the bottoms of the first heat storage chamber and the second heat storage chamber are connected to a purification device via a connecting pipe, the output end of the purification device is fixedly installed with a second fan, and the output end of the second fan is fixedly installed with a chimney.
[0010] It should be noted in the solution that the heat exchanger is a plate heat exchanger, and the heat output end of the heat exchanger is connected to other related structures through a pipeline.
[0011] It is further worth noting that a ceramic heat storage body is arranged in the first heat storage chamber and the second heat storage chamber, and a lifting valve for alternating switching is arranged at the input end and the output end of the first heat storage chamber and the second heat storage chamber through a connecting pipe at the bottom end.
[0012] It should be further explained that a fan is provided through a pipeline between the incineration chamber and the pipeline at the input end of the purification device.
[0013] As a preferred embodiment, the purification device is provided with an S-shaped pipe with a water stop valve and is connected to the input pipe and the output end is arranged near the bottom. The purification device is filled with alkaline purification liquid, and an activated carbon adsorption plate is arranged on the top of the purification liquid in the purification device.
[0014] Compared with the prior art, the utility model provides a purification device for collaboratively removing VOCs and NOx, which has at least the following beneficial effects:
[0015] (1) The heat exchanger installed on the ventilation pipe can exchange heat with the exhaust gas entering the heat storage chamber, so as to reduce the exhaust gas temperature and avoid excessive exhaust gas temperature causing the temperature of the ceramic heat storage body in the heat storage chamber to rise, thereby preventing the exhaust gas from being fully burned and decomposed through the incineration chamber, thereby improving the exhaust gas decomposition efficiency. At the same time, the heat is transferred to the front-end denitrification device through the heat exchanger to achieve temperature control of the front-end denitrification device, thereby realizing energy utilization and coordinated NOx treatment.
[0016] (2) By installing a purification device at the front end of the chimney, after the waste gas is incinerated and decomposed, the purified waste gas is washed and purified, which can effectively remove the odor in the purified waste gas and further purify the waste gas, thereby improving the purification standard of the exhausted waste gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the working principle of a traditional two-chamber RTO;
[0018] Figure 2 It is a schematic diagram of the structure of the utility model;
[0019] Figure 3 This is a structural schematic diagram of another viewing angle of the utility model;
[0020] Figure 4 It is a schematic diagram of the working principle of the utility model.
[0021] In the figure: 1. air intake pipe; 2. first fan; 3. heat exchanger; 4. first heat storage chamber; 5. second heat storage chamber; 6. incineration chamber; 7. purification device; 8. chimney; 9. filter; 10. second fan; 11. front-end denitrification device. DETAILED DESCRIPTION
[0022] The present invention will be further described below in conjunction with the embodiments.
[0023] See also Figure 2-4 The utility model provides a purification device for synergistically removing VOCs and NOx, including an air intake pipe 1 and a first fan 2, a filter 9 is connected between the air intake pipe 1 and the first fan 2 through a flange, the other end of the first fan 2 is fixedly connected to a heat exchanger 3 through a connecting pipe, the other end of the heat exchanger 3 is fixedly connected to a first heat storage chamber 4 and a second heat storage chamber 5 through a connecting pipe, the heat output end of the heat exchanger 3 is fixedly connected to a front-end denitration device 11 through a pipeline, the tops of the first heat storage chamber 4 and the second heat storage chamber 5 are connected to an incineration chamber 6, the bottoms of the first heat storage chamber 4 and the second heat storage chamber 5 are connected to a purification device 7 through a connecting pipe, the output end of the purification device 7 is fixedly installed with a second fan 10, and the output end of the second fan 10 is fixedly installed with a chimney 8.
[0024] Further as Figure 2 , Figure 3 and Figure 4 As shown, it is worth explaining in detail that the heat exchanger 3 is a plate heat exchanger, and the heat output end of the heat exchanger 3 is connected to other related structures through a pipeline.
[0025] NOx removal is divided into catalytic denitrification and non-catalytic denitrification. The exhaust gas passes through the front-end denitrification device 11 and cooperates with the heat exchanger 3 to achieve energy synergistic treatment. Some light hydrocarbon substances in the gas treated by the front-end RTO can also act as reducing agent substances during catalytic denitrification. Through the synergistic utilization of materials and energy, the synergistic treatment efficiency is greatly improved.
[0026] At the same time, the heat of the discharged exhaust gas is utilized through the setting of the heat exchanger 3, and the temperature can be controlled by the front-end denitrification device 11. Since NOx removal requires a certain temperature, the temperature required for catalytic denitrification is lower, and the temperature for non-catalytic denitrification is higher. Heat is transferred through the heat exchanger 3 to increase the temperature in the front-end denitrification device 11, realize energy utilization synergy, and further improve the removal of NOx in the exhaust gas. The purified exhaust gas is deodorized by the purification device 7, and the exhaust gas is further purified to improve the exhaust gas discharge standard.
[0027] Further as Figure 2 , Figure 3 and Figure 4As shown, it is worth specifically explaining that a ceramic heat storage body is arranged in the first heat storage chamber 4 and the second heat storage chamber 5, and a lifting valve for alternate switching is arranged at the input end and the output end of the first heat storage chamber 4 and the second heat storage chamber 5 through a connecting pipe at the bottom end;
[0028] The low-temperature waste gas to be treated enters the first regenerator 4 through the first fan 2. The ceramic regenerator releases heat and the temperature decreases. The organic waste gas rises to a higher temperature and then enters the oxidation chamber. In the oxidation chamber, the burner burns to supplement the heat, so that the waste gas rises to the set oxidation temperature (760°C). The organic components in the waste gas are decomposed into CO2 and H2O. Since the waste gas has been preheated in the regenerator, the amount of added fuel is small. The purified high-temperature waste gas leaves the oxidation chamber and enters the regenerator 2, releasing heat. After the temperature drops, it is discharged into the air through the chimney 8 by the exhaust fan. The ceramic regenerator in the regenerator 2 absorbs heat and "stores" a large amount of heat (for heating the waste gas in the next cycle). After a cycle is completed, the air inlet and outlet valves are switched once to change the airflow direction (enter the next cycle). The waste gas enters the second regenerator 5, and the purified gas is discharged from the first regenerator 4, and this is repeated alternately.
[0029] Further as Figure 2 , Figure 3 and Figure 4 As shown, it is worth explaining in detail that a fan is arranged between the incineration chamber 6 and the pipeline at the input end of the purification device 7. Through the arrangement of the fan, when the incineration chamber 6 stops working, the waste gas remaining in the incineration chamber 6 is difficult to be discharged, and it is extracted by the fan and purified and discharged in the purification device 7.
[0030] Further as Figure 2 , Figure 3 and Figure 4 As shown, it is worth specifically explaining that an S-shaped pipe with a water stop valve is provided in the purification device 7 and is connected to the input pipe and the output end is arranged near the bottom. The purification device 7 is filled with alkaline purification liquid. An activated carbon adsorption plate is arranged on the upper part of the purification liquid in the purification device 7. The exhaust gas contacts the alkaline solution in the acid gas and alkaline solution reaction area and is neutralized by the alkaline substance in the solution, thereby neutralizing the acidic components in the exhaust gas into salts.
[0031] When the exhaust gas passes through the water pool, due to the cooling effect of the water, solid pollutants such as smoke and particulate matter in the exhaust gas will precipitate in the water, and gaseous pollutants will be discharged into the water through the mass transfer between water and gas to achieve the purification effect. The harmful gases in the exhaust gas dissolve into the water, and through the mixing and stirring of water, the gas molecules and water molecules contact more frequently, thereby accelerating the dissolution rate of the gas in the water. This method can be used to purify harmful gases such as carbon monoxide and sulfur dioxide in the exhaust gas.
[0032] According to the above working process, it can be known that: through the heat exchanger 3 arranged on the ventilation pipe, the exhaust gas entering the heat storage chamber can be heat exchanged to reduce the exhaust gas temperature, avoid excessive exhaust gas temperature causing the temperature of the ceramic heat storage body in the heat storage chamber to rise, and then the exhaust gas cannot be fully burned and decomposed through the incineration chamber 6, thereby improving the exhaust gas decomposition efficiency. At the same time, heat is transferred to the front-end denitrification device 11 through the heat exchanger 3, realizing the temperature control of the front-end denitrification device 11, and then realizing energy utilization and coordinated NOx treatment.
[0033] This solution has the following working process: when this device is used, the exhaust gas enters the filter 9 through the intake pipe 1, and the smoke and debris in the exhaust gas are filtered by the filter 9. The heat of the exhaust gas discharged is utilized by the setting of the heat exchanger 3. The temperature control can be achieved through the front-end denitrification device 11. Since NOx removal requires a certain temperature, the temperature required for catalytic denitrification is lower, and the temperature for non-catalytic denitrification is higher. Heat is transferred through the heat exchanger 3 to increase the temperature in the front-end denitrification device 11, realizing energy utilization synergy. At the same time, some light hydrocarbon substances in the gas treated by the front-end RTO can also act as reducing agents during catalytic denitrification, realizing material utilization synergy, greatly improving the NOx synergistic treatment efficiency, and the exhaust gas passes through When the first heat storage chamber 4 is in operation, the lifting valve at the input end of the second heat storage chamber 5 is closed, and the lifting valve at the output end is opened, and the exhaust gas enters the first heat storage chamber 4. Due to the action in the incineration chamber 6, the ceramic heat storage body has been preheated. By heating the organic exhaust gas to 760°C, the VOC in the exhaust gas is oxidized and decomposed into harmless CO2 and H2O. The heat of the high-temperature gas during oxidation is "stored" by the heat storage body and used to preheat the newly entered organic exhaust gas, saving the fuel consumption required for heating. At the same time, the decomposed exhaust gas is passed into the purification device 7 through the output end connecting pipe, and the odor in the exhaust gas is purified by the purification liquid and activated carbon adsorption plate arranged in the purification device 7. Finally, the purified exhaust gas is discharged through the chimney 8 through the filter 9.
[0034] In summary: by means of the heat exchanger 3 arranged on the ventilation pipe, the exhaust gas entering the heat storage chamber can be heat exchanged, so that the exhaust gas temperature can be reduced, and the excessively high exhaust gas temperature can be avoided so that the temperature of the ceramic heat storage body in the heat storage chamber increases, and the exhaust gas cannot be fully burned and decomposed through the incineration chamber 6, thereby improving the exhaust gas decomposition efficiency. At the same time, the heat is transferred to the front-end denitrification device 11 through the heat exchanger 3, so that the temperature of the front-end denitrification device 11 is controlled, and thus the energy utilization and coordinated NOx treatment are realized; by means of the purification device 7 arranged at the front end of the chimney 8, after the exhaust gas is incinerated and decomposed and purified, the purified exhaust gas is washed and purified, which can effectively remove the odor in the purified exhaust gas and further purify the exhaust gas, thereby improving the purification standard of the exhausted exhaust gas.
Claims
1. A purification device for collaboratively removing VOCs and NOx, comprising an air intake pipe (1) and a first fan (2), characterized in that: A filter (9) is connected between the air intake pipe (1) and the first fan (2) via a flange; the other end of the first fan (2) is fixedly connected to a heat exchanger (3) via a connecting pipe; the other end of the heat exchanger (3) is fixedly connected to a first heat storage chamber (4) and a second heat storage chamber (5) via a connecting pipe; the heat output end of the heat exchanger (3) is fixedly connected to a front-end denitration device (11) via a pipeline; an incineration chamber (6) is provided at the top of the first heat storage chamber (4) and the second heat storage chamber (5); the bottom of the first heat storage chamber (4) and the second heat storage chamber (5) are connected to a purification device (7) via a connecting pipe; a second fan (10) is fixedly installed at the output end of the purification device (7); and a chimney (8) is fixedly installed at the output end of the second fan (10).
2. A purification device for collaboratively removing VOCs and NOx according to claim 1, characterized in that: The heat exchanger (3) is a plate-type heat exchanger, and the heat output end of the heat exchanger (3) is connected to other related structures via a pipeline.
3. A purification device for collaboratively removing VOCs and NOx according to claim 1, characterized in that: Ceramic heat storage bodies are arranged in the first heat storage chamber (4) and the second heat storage chamber (5), and lift valves that switch alternately are arranged at the input end and the output end of the first heat storage chamber (4) and the second heat storage chamber (5) through connecting pipes at the bottom ends.
4. A purification device for collaboratively removing VOCs and NOx according to claim 1, characterized in that: A fan is provided between the incineration chamber (6) and the pipeline at the input end of the purification device (7).
5. The purification device for collaboratively removing VOCs and NOx according to claim 1, characterized in that: The purification device (7) is provided with an S-shaped pipe with a water stop valve and is connected to the input pipe, and the output end is arranged near the bottom. The purification device (7) is filled with alkaline purification liquid, and an activated carbon adsorption plate is arranged on the top of the purification liquid in the purification device (7).