A tail gas treatment device and method

Abstract

The application discloses a tail gas treatment device and method, which comprises a water washing tower, a filler, a sieve plate, a liquid phase stabilization zone, a circulating pump and a control unit.

Description

Technical Field

[0001] This invention belongs to the field of exhaust gas treatment technology, and more specifically, relates to an exhaust gas treatment device and method. Background Technology

[0002] Industrial plants generate large amounts of exhaust gas, some of which is continuously and stably emitted, while others are emitted intermittently and in varying quantities. For intermittent emissions, exhaust gas treatment systems are typically designed based on the maximum possible emission, resulting in a large design margin during normal operation and an unnecessary increase in water and energy consumption. For exhaust gases containing both water-soluble and non-water-soluble components, or those containing media with low solubility, traditional exhaust gas washing treatment systems often require a separate oil tank for the non-water-soluble or low-solubility precipitated media. However, because the content of these media is small, the oil tanks are usually small, leading to inaccurate level gauge readings. Furthermore, the disturbance of the liquid phase by the exhaust gas easily causes level fluctuations within the tower, resulting in inaccurate interface gauge readings. This often leads to the entrainment of water phase in the extraction of non-water-soluble or low-solubility media, increasing the workload and difficulty of subsequent treatment processes. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing an exhaust gas treatment device and method that can reduce water and energy consumption while ensuring treatment effectiveness.

[0004] To achieve the above objectives, the present invention provides an exhaust gas treatment device, the device comprising: A water washing tower, wherein an air inlet and an air outlet are respectively provided at the bottom and top of the water washing tower, and a flow meter and an analyzer are respectively connected to the air inlet and the air outlet; The packing material is disposed inside the upper end of the water washing tower, and a water inlet structure is provided above the packing material; A sieve plate is disposed inside the lower end of the water washing tower. One side of the sieve plate is provided with sieve holes, and the other side of the sieve plate is a blind plate. A liquid phase stabilization zone is provided above the other side of the sieve plate, and a channel communicating with the interior of the water washing tower is provided at the lower end of the liquid phase stabilization zone. A circulating pump, the input end of which is connected to the liquid phase stabilization zone, and the output end of which is connected to the water inlet structure; The control unit is electrically connected to the flow meter, the analyzer, and the circulating pump.

[0005] Optionally, the water inlet structure includes a liquid distributor.

[0006] Optionally, the aperture ratio of the sieve holes on the side of the sieve plate is 30%-80%.

[0007] Optionally, the liquid phase stabilization zone includes a baffle plate and a partition plate. The baffle plate is disposed above the other side of the sieve plate and forms a first gap with the sieve plate. The upper end of the partition plate is connected to the side of the baffle plate away from the tower wall of the water washing tower. A second gap is provided between the lower end of the partition plate and the sieve plate. The baffle plate, the partition plate, and the other side of the sieve plate, together with the tower wall of the water washing tower, form the liquid phase stabilization zone.

[0008] Optionally, the height of the second gap is 2% to 20% of the height of the partition, and one side of the liquid phase stable zone is used to connect the level gauge, the interface gauge and the circulation pump.

[0009] Optionally, the lower part of the washing tower is provided with a fresh water inlet, which is located below the sieve plate.

[0010] Optionally, the output end of the circulating pump is connected to a first pipeline and a second pipeline, the first pipeline being connected to the water inlet structure, and the second pipeline being equipped with a drain valve.

[0011] The present invention also provides an exhaust gas treatment method, utilizing the above-mentioned exhaust gas treatment device, the method comprising: The untreated exhaust gas is fed into a water scrubbing tower for primary exhaust gas treatment, and the flow rate of the untreated exhaust gas is monitored. Analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment; Whether to perform secondary exhaust gas treatment is determined based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas.

[0012] Optionally, determining whether to perform secondary exhaust gas treatment based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas includes: If the flow rate of the untreated exhaust gas is greater than 80 Nm 3 If the exhaust gas temperature is / h, then secondary exhaust gas treatment will be performed; If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the harmful gas content of the treated exhaust gas meets the standard, then secondary exhaust gas treatment is not required. If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the harmful gas content in the treated exhaust gas does not meet the standard, then secondary exhaust gas treatment shall be performed.

[0013] Optionally, a flow meter is used to monitor the flow rate of the untreated exhaust gas, and the analyzer is used to analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment.

[0014] This invention provides an exhaust gas treatment device and method, the advantages of which are: 1. The control unit of the device can control the device to perform primary or secondary tail gas treatment based on the monitoring results of the flow meter and the analyzer. The efficiency of the water washing can be improved by performing secondary water washing on the tail gas. 2. This device has high operational flexibility and is suitable for operating conditions with large fluctuations in exhaust gas flow. 3. When performing secondary tail gas treatment, the device can utilize water in stages, reducing system water and energy consumption and improving the economic efficiency of the device. 4. The device has a liquid phase stability zone structure, which can ensure the accuracy of interface and liquid level measurement and the safety of circulating pump operation; 5. The perforation structure of the sieve holes on the sieve plate of this device can achieve uniform gas phase distribution and improve mass transfer efficiency. 6. This device can handle exhaust gases containing water-soluble media, non-water-soluble media, or media with low solubility.

[0015] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0017] Figure 1 A schematic diagram of an exhaust gas treatment device according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram of the structure of a screen plate of an exhaust gas treatment device according to an embodiment of the present invention is shown.

[0019] Figure 3 A flowchart of an exhaust gas treatment method according to an embodiment of the present invention is shown.

[0020] Explanation of reference numerals in the attached figures: 1. Water washing tower; 2. Air inlet; 3. Air outlet; 4. Flow meter; 5. Analyzer; 6. Packing material; 7. Water inlet structure; 8. Sieve plate; 9. Sieve holes; 10. Blind flange; 11. Liquid phase stability zone; 12. Channel; 13. Circulating pump; 14. Flow shield; 15. Baffle plate; 16. Fresh water inlet; 17. First pipeline; 18. Second pipeline; 19. Drain valve. Detailed Implementation

[0021] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0022] This invention provides an exhaust gas treatment device, the device comprising: The water washing tower has an air inlet and an air outlet at its bottom and top, respectively, and a flow meter and an analyzer are connected to the air inlet and the air outlet, respectively. The packing material is installed inside the upper part of the water washing tower, and a water inlet structure is provided above the packing material. The sieve plate is installed inside the lower end of the water washing tower. One side of the sieve plate is provided with sieve holes, and the other side of the sieve plate is a blind plate. The liquid phase stabilization zone is located above the other side of the sieve plate, and a channel connecting the lower end of the liquid phase stabilization zone to the interior of the water washing tower is provided. The circulation pump has its input end connected to the liquid phase stabilization zone and its output end connected to the water inlet structure. The control unit is electrically connected to the flow meter, analyzer, and circulating pump.

[0023] Specifically, untreated exhaust gas enters the bottom of the water scrubbing tower through the inlet. The flow meter can monitor the flow rate of the untreated exhaust gas in real time. The untreated exhaust gas is treated inside the water scrubbing tower. Water enters the water scrubbing tower from the inlet structure, falls through the packing and comes into contact with the untreated exhaust gas. Non-water-soluble media overflow to the upper part of the liquid phase stabilization zone and are discharged from the water scrubbing tower through the outlet. Water-soluble media are sent out through the bottom channel of the liquid phase stabilization zone. The analyzer can analyze the content of harmful gases in the treated exhaust gas discharged from the outlet. The control unit controls whether to perform secondary treatment of the exhaust gas based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas. During secondary treatment of the exhaust gas, the circulation pump is started to return most of the circulating water to the inlet structure, and a small amount of wastewater is sent out of the boundary area.

[0024] Optionally, the water inlet structure includes a liquid distributor.

[0025] Specifically, the liquid distributor enables the influent water to be evenly distributed above the packing material, thereby improving the mass transfer effect.

[0026] Optionally, the opening rate of the sieve holes on one side of the sieve plate is 30%-80%.

[0027] Specifically, the sieve holes on one side of the sieve plate allow the gas phase to be distributed within the water washing tower for washing.

[0028] Optionally, the liquid phase stable zone includes a baffle plate and a partition plate. The baffle plate is disposed above the other side of the sieve plate and forms a first gap with the sieve plate. The upper end of the partition plate is connected to the side of the baffle plate away from the tower wall of the water washing tower. A second gap is provided between the lower end of the partition plate and the sieve plate. The other side of the baffle plate, the partition plate, and the sieve plate, together with the tower wall of the water washing tower, forms the liquid phase stable zone.

[0029] Specifically, the second gap forms a channel, and the height of the second gap is the height of the channel.

[0030] Optionally, the height of the second gap is 2% to 20% of the height of the partition plate, and one side of the liquid phase stable zone is used to connect the level gauge, interface gauge and circulating pump.

[0031] Specifically, the setting of the liquid phase stabilization zone ensures the stability of the internal liquid phase, thereby guaranteeing the accuracy of interface and liquid level measurements as well as the safety of the operation of the circulating pump (S5).

[0032] Optionally, a fresh water inlet is provided at the bottom of the washing tower, located below the screen plate.

[0033] Specifically, the fresh water inlet is used to replenish fresh water to the bottom of the water washing tower. The fresh water is replenished intermittently to maintain a stable liquid level in the water washing tower and ensure the washing effect.

[0034] Optionally, a first pipeline and a second pipeline are connected to the output end of the circulating pump. The first pipeline is connected to the water inlet structure, and a drain valve is installed on the second pipeline.

[0035] Specifically, during the secondary exhaust gas treatment, the circulation pump is started, most of the circulating water is returned to the water washing tower through the first pipeline, and a small amount of sewage is sent out of the boundary through the second pipeline.

[0036] The present invention also provides an exhaust gas treatment method, utilizing the above-mentioned exhaust gas treatment device, the method comprising: The untreated exhaust gas is fed into a water scrubbing tower for primary exhaust gas treatment, and the flow rate of the untreated exhaust gas is monitored. Analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment; Whether secondary exhaust gas treatment is required is determined based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas.

[0037] Specifically, the primary and secondary tail gas treatment systems can be automatically switched, offering high operational flexibility and making them suitable for operating conditions with large fluctuations in tail gas flow. During secondary tail gas treatment, water can be used in stages, reducing system water and energy consumption and improving the economic efficiency of the equipment.

[0038] Optionally, determining whether to perform secondary exhaust gas treatment based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas includes: If the flow rate of the untreated exhaust gas is greater than 80 Nm3 If the exhaust gas temperature is / h, then secondary exhaust gas treatment will be performed; If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the exhaust gas concentration is within a certain range (e.g., / h) and the harmful gas content of the treated exhaust gas meets the standard, then secondary exhaust gas treatment will not be performed. If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the concentration of harmful gases in the treated exhaust gas is less than 100 liters per hour, then secondary exhaust gas treatment will be performed.

[0039] Optionally, a flow meter can be used to monitor the flow rate of untreated exhaust gas, and an analyzer can be used to analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment.

[0040] Example

[0041] like Figure 1 and Figure 2 As shown, the present invention provides an exhaust gas treatment device, the device comprising: The water washing tower 1 has an air inlet 2 and an air outlet 3 at its bottom and top, respectively. A flow meter 4 and an analyzer 5 are connected to the air inlet 2 and the air outlet 3, respectively. Packing 6 is installed inside the upper end of the water washing tower 1, and a water inlet structure 7 is installed above the packing 6. Screen plate 8 is installed inside the lower end of water washing tower 1. Screen plate 8 has screen holes 9 on one side and blind plate 10 on the other side. The liquid phase stabilization zone 11 is located above the other side of the sieve plate 8, and the lower end of the liquid phase stabilization zone 11 is provided with a channel 12 that communicates with the interior of the water washing tower 1. The circulation pump 13 has its input end connected to the liquid phase stabilization zone 11 and its output end connected to the water inlet structure 7. The control unit is electrically connected to the flow meter 4, the analyzer 5, and the circulating pump 13.

[0042] In this embodiment, the water inlet structure 7 includes a liquid distributor.

[0043] In this embodiment, the opening rate of the sieve hole 9 on one side of the sieve plate 8 is 50%-70%.

[0044] In this embodiment, the liquid phase stabilization zone 11 includes a baffle plate 14 and a partition plate 15. The baffle plate 14 is disposed above the other side of the sieve plate 8 and forms a first gap with the sieve plate 8. The upper end of the partition plate 15 is connected to the side of the baffle plate 14 away from the tower wall of the water washing tower 1. A second gap is provided between the lower end of the partition plate 15 and the sieve plate 8. The baffle plate 14, the partition plate 15 and the other side of the sieve plate 8 form the liquid phase stabilization zone 11 with the tower wall of the water washing tower 1.

[0045] In this embodiment, the height of the second gap is 5% to 10% of the height of the partition 15, and one side of the liquid phase stable zone 11 is used to connect the level gauge, the interface gauge and the circulation pump.

[0046] In this embodiment, a fresh water inlet 16 is provided at the lower part of the water washing tower 1, and the fresh water inlet 16 is located below the sieve plate 8.

[0047] In this embodiment, a first pipeline 17 and a second pipeline 18 are connected to the output end of the circulating pump 13. The first pipeline 17 is connected to the water inlet structure 17, and a drain valve 19 is provided on the second pipeline 18.

[0048] like Figure 3 As shown, the present invention also provides an exhaust gas treatment method, utilizing the above-described exhaust gas treatment device, the method comprising: The untreated exhaust gas is fed into a water scrubbing tower for primary exhaust gas treatment, and the flow rate of the untreated exhaust gas is monitored. Analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment; Whether secondary exhaust gas treatment is required is determined based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas.

[0049] In this embodiment, determining whether to perform secondary exhaust gas treatment based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas includes: If the flow rate of the untreated exhaust gas is greater than 80 Nm 3 If the exhaust gas temperature is / h, then secondary exhaust gas treatment will be performed; If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the exhaust gas concentration is within a certain range (e.g., / h) and the harmful gas content of the treated exhaust gas meets the standard, then secondary exhaust gas treatment will not be performed. If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the concentration of harmful gases in the treated exhaust gas is less than 100 liters per hour, then secondary exhaust gas treatment will be performed.

[0050] In this embodiment, a flow meter is used to monitor the flow rate of untreated exhaust gas, and an analyzer is used to analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment.

[0051] In summary, when the exhaust gas treatment method provided by this invention is implemented, using the above-mentioned exhaust gas treatment device, taking untreated tank area exhaust gas containing tert-butanol with low solubility and a large amount of nitrogen as an example: the flow rate of untreated tank area exhaust gas fluctuates greatly, and normally it is stable at 20-80 Nm³ due to intermittent discharge from the breather valve. 3 Between / h, when abnormal operating conditions occur (such as breather valve failure, tank loading), the exhaust gas flow rate can reach 500Nm. 3 / h. Unabsorbed tert-butanol overflows through baffle 15 to the upper part of the liquid-phase stable zone 11 and is discharged; tert-butanol absorbed by water flows through the channel to the bottom of the liquid-phase stable zone 11 and is discharged; low-flow tail gas (20-80 Nm³). 3 The high-flow exhaust gas (>80Nm³ / h) undergoes primary water washing. 3 If the COD analyzer shows that the low-flow tail gas fails to meet the standard after primary water washing, a two-stage water washing is performed; primary and two-stage water washing can be automatically switched. The flow rate of the untreated tail gas is detected by flow meter 4, and the COD content of the treated tail gas is detected by analyzer 5, thus determining whether to perform primary or two-stage water washing. Primary water washing: Low-flow tail gas S1 enters the bottom of the sieve plate 8 of the water washing tower 1. The gas phase is evenly distributed within the water washing tower 1 through the sieve holes 9 on one side of the sieve plate 8 for primary water washing. The gas phase is directly sent to the outside through the outlet 3S2. Secondary water washing: High-flow tail gas or gas that fails to meet the standard after primary water washing enters the bottom of the sieve plate 8 of the water washing tower 1. The circulating pump 13 starts, and most of the circulating water returns to the water washing tower 1, while a small amount of wastewater S4 is sent out of the boundary area. Fresh water S3 is intermittently added through the fresh water inlet 16 to maintain a stable liquid level and ensure the water washing effect.

[0052] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for treating exhaust gas, utilizing an exhaust gas treatment device, characterized in that, The device includes: A water washing tower, wherein an air inlet and an air outlet are respectively provided at the bottom and top of the water washing tower, and a flow meter and an analyzer are respectively connected to the air inlet and the air outlet; The packing material is disposed inside the upper end of the water washing tower, and a water inlet structure is provided above the packing material; A sieve plate is disposed inside the lower end of the water washing tower. One side of the sieve plate is provided with sieve holes, and the other side of the sieve plate is a blind plate. A liquid phase stabilization zone is provided above the other side of the sieve plate, and a channel communicating with the interior of the water washing tower is provided at the lower end of the liquid phase stabilization zone. A circulating pump, the input end of which is connected to the liquid phase stabilization zone, and the output end of which is connected to the water inlet structure; A control unit, which is electrically connected to the flow meter, the analyzer, and the circulating pump; The liquid phase stabilization zone includes a flow shield and a baffle. The flow shield is disposed above the other side of the sieve plate and forms a first gap with the sieve plate. The upper end of the baffle is connected to the side of the flow shield away from the tower wall of the water washing tower. A second gap is provided between the lower end of the baffle and the sieve plate. The flow shield, the baffle, and the other side of the sieve plate, together with the tower wall of the water washing tower, form the liquid phase stabilization zone. One side of the liquid phase stable zone is used to connect the level gauge, the interface gauge and the circulation pump; The method includes: The untreated exhaust gas is fed into a water scrubbing tower for primary exhaust gas treatment, and the flow rate of the untreated exhaust gas is monitored. Analyze the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment; Whether to perform secondary exhaust gas treatment is determined based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas. During secondary exhaust gas treatment, the circulation pump is started to return most of the circulating water to the inlet structure, and a small amount of sewage is discharged.

2. The exhaust gas treatment method according to claim 1, characterized in that, The water inlet structure includes a liquid distributor.

3. The exhaust gas treatment method according to claim 1, characterized in that, The aperture ratio of the sieve holes on one side of the sieve plate is 30%-80%.

4. The exhaust gas treatment method according to claim 1, characterized in that, The height of the second gap is 2% to 20% of the height of the partition.

5. The exhaust gas treatment method according to claim 1, characterized in that, The washing tower is provided with a fresh water inlet at its lower part, which is located below the sieve plate.

6. The exhaust gas treatment method according to claim 1, characterized in that, The output end of the circulating pump is connected to a first pipeline and a second pipeline. The first pipeline is connected to the water inlet structure, and a drain valve is installed on the second pipeline.

7. The exhaust gas treatment method according to claim 1, characterized in that, The step of determining whether to perform secondary exhaust gas treatment based on the flow rate of the untreated exhaust gas and the content of harmful gases in the treated exhaust gas includes: If the flow rate of the untreated exhaust gas is greater than 80 Nm 3 If the exhaust gas temperature is / h, then secondary exhaust gas treatment will be performed; If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the harmful gas content of the treated exhaust gas meets the standard, then secondary exhaust gas treatment is not required. If the flow rate of the untreated exhaust gas is 20-80 Nm 3 If the harmful gas content in the treated exhaust gas does not meet the standard, then secondary exhaust gas treatment shall be performed.

8. The exhaust gas treatment method according to claim 1, characterized in that, The flow rate of the untreated exhaust gas is monitored using a flow meter, and the content of harmful gases in the treated exhaust gas after primary exhaust gas treatment is analyzed using the analyzer.

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