An experimental gas recycling and treatment system

Abstract

The present invention discloses an experimental gas circulation recovery and treatment system, comprising an experimental gas supply device, a heater, a reactor, a circulation pipeline, and an exhaust gas absorption pipeline; the experimental gas supply device is connected to the heater, the outlet of the heater is connected to the reactor, and the outlet of the reactor is connected to the circulation pipeline and the exhaust gas absorption pipeline; a circulation fan and an alkali powder filter device are provided on the circulation pipeline; a cooling device and an exhaust gas absorption device are provided on the exhaust gas absorption pipeline; the gas outlet of the alkali powder filter device is connected to the air intake pipeline; the alkali powder filter device has an absorption chamber; a folding baffle is provided on the top of the absorption chamber, and a vortex port is formed between the folding baffle and the wall of the absorption chamber; the gas outlet of the alkali powder filter device is provided with a first turning channel and a second turning channel; the first turning channel and the second turning channel are spliced ​​into a U-shaped outlet channel. The system has a relatively simple structure, can save experimental gas, and can achieve effective gas recovery and exhaust gas treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of gas distribution simulation experiments, and in particular relates to an experimental gas circulation recovery and processing system suitable for pilot bench testing in a catalyst laboratory. Background Art

[0002] During the catalyst gas distribution simulation experiment, the test bench needs to simulate real flue gas conditions, and its control parameters include temperature, NO, SO2, SO3, NH3, humidity, oxygen content, etc. Among them, NO, SO2, SO3, and NH3 are purchased gases, and the gas flow rate can be controlled by a flow control unit to configure the corresponding concentration of reaction gas. The simulated flue gas entering the catalyst reactor needs to reach the required reaction temperature; the gas discharged from the catalyst reactor needs to have its residual heat recovered; in addition, after the experiment is over, the exhaust gas generated also needs to be treated. The existing catalyst simulation experimental system is relatively complex, consumes a lot of gas, and generates a large amount of waste gas. It also does not have a complete and effective function of recovering gas and gas residual heat and treating exhaust gas. The experimental cost is high, the energy consumption is high, and it is not conducive to environmental protection and resource conservation. Summary of the Invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide an experimental gas circulation recovery and treatment system. The system has a relatively simple structure, can save the amount of experimental gas, can realize the recovery of gas and gas waste heat, and effectively treat the exhaust gas at the end of the experiment, and can reduce the amount of waste liquid for treating the exhaust gas, saving experimental costs, and is beneficial to environmental protection and resource conservation.

[0004] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0005] An experimental gas recycling and recovery processing system includes an experimental gas supply device, a heater, a reactor, a circulation pipeline and an exhaust gas absorption pipeline;

[0006] The outlet of the experimental gas supply device is connected to the heater through an air inlet pipeline, the outlet of the heater is connected to the reactor, and the outlet of the reactor is connected to the circulation pipeline and the tail gas absorption pipeline; the circulation pipeline and the tail gas absorption pipeline are arranged in parallel; a circulation fan and an alkali powder filter device are provided on the circulation pipeline; a cooling device and a tail gas absorption device connected to the outlet of the cooling device are provided on the tail gas absorption pipeline; the gas outlet of the alkali powder filter device is connected to the air inlet pipeline;

[0007] The alkali powder filter device has an absorption chamber with alkali powder arranged in it; the top of the absorption chamber of the alkali powder filter device is provided with an inwardly folded baffle, and a vortex port is formed between the folded baffle and the cavity wall of the absorption chamber; the gas outlet of the alkali powder filter device is provided with a first turning channel and a second turning channel; the first turning channel is an inverted L-shape, which is connected to the vortex port, and the second turning channel is a regular L-shape, and the first turning channel and the second turning channel are spliced ​​into a U-shaped outlet channel.

[0008] As a further improvement to the above technical solution of the present invention, a flow meter and flue gas analyzer are installed on the air inlet pipe, and a thermometer is installed on the pipe between the heater and the reactor. The flue gas analyzer can monitor the gas composition in real time; the flow meter can monitor the gas flow in real time to facilitate the flow control of the experimental gas; and the thermometer can monitor the gas temperature to ensure that the temperature of the gas entering the reactor does not fall below the experimental design temperature.

[0009] As a further improvement of the above technical solution of the present invention, a flow regulating valve is provided between the outlet of the experimental gas supply device and the air inlet pipeline to regulate the flow of the experimental gas.

[0010] As a further improvement of the above technical solution of the present invention, a circulation control valve is provided on the circulation pipeline, and an exhaust gas control valve is provided on the exhaust gas absorption pipeline.

[0011] As a further improvement of the above technical solution of the present invention, the angle between the folding baffle and the cavity wall of the absorption chamber is less than 145°; a vortex mouth can be formed between the folding baffle and the cavity wall of the absorption chamber, thereby changing the trajectory of some alkali powder fine particles in the gas and forming an air flow vortex, so that the alkali powder fine particles are separated from the air flow and returned to the absorption chamber of the alkali powder filtering device, preventing the alkali powder from being carried out by the air flow to block the pipeline.

[0012] As a further improvement of the above technical solution of the present invention, the alkali powder filtering device has an alkali powder discharge port, which is connected to the tail gas absorption device. The replaced alkali powder can be discharged from the alkali powder discharge port and then enter the tail gas absorption device for treatment.

[0013] As a further improvement of the above technical solution of the present invention, the ratio of the height to the inner diameter of the alkali powder filtering device is greater than 3, which can control the suspension height of the alkali powder and prevent the alkali powder from being carried out by the air flow.

[0014] As a further improvement to the above technical solution of the present invention, the outlet width of the first turning channel is smaller than the outlet width of the second turning channel. The first turning channel and the second turning channel cooperate to allow the carried out finer particles to settle, preventing the alkali powder from being carried out by the airflow.

[0015] As a further improvement of the above technical solution of the present invention, a fixed discharge port is provided at the bottom of the U-shaped outlet channel of the alkali powder filtering device, through which the alkali powder particles etc. deposited at the U-shaped outlet channel can be discharged.

[0016] As a further improvement of the above technical solution of the present invention, a spray head is provided in the cooling device; the spray head is externally connected to a water circuit and cools the exhaust gas by spraying water mist.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention utilizes a circulation pipeline to recover the gas discharged from the reactor, so that the high-temperature gas circulates into the reactor for reaction. This can greatly reduce the amount of gas used in the experiment and can realize the recovery of the waste heat of the gas, thereby reducing the heating energy consumption. There is no need to install heat exchange and cooling devices, so that the entire system can be simplified, the experimental cost is reduced, and it is beneficial to environmental protection and resource conservation.

[0019] (2) The present invention provides an alkali powder filtering device on the circulation pipeline, so that the alkali powder can be used to absorb the increased SO3 content in the gas after the reaction, so as to avoid the continuous accumulation of SO3 and the resulting impact on catalyst detection;

[0020] (3) The top of the absorption chamber of the alkali powder filtering device is provided with an inwardly folded baffle, and a vortex outlet is formed between the folded baffle and the cavity wall of the absorption chamber. The vortex outlet can change the trajectory of some alkali powder fine particles and form an air flow vortex, so that the alkali powder fine particles are separated from the air flow and return to the absorption chamber, thereby preventing the alkali powder from being carried out by the air flow and clogging the pipeline; and the outlet of the alkali powder filtering device is provided with a first turning channel and a second turning channel, and the outlet width of the first turning channel is smaller than the outlet width of the second turning channel, so that the first turning channel and the second turning channel cooperate to allow the finer particles carried out to be deposited, further preventing the alkali powder fine particles from being carried out by the air flow.

[0021] (4) At the end of the experiment, the tail gas enters the tail gas absorption pipeline, and the tail gas is first cooled by the cooling device, and then purified by the tail gas absorption device; the amount of waste gas and waste liquid generated by the system of the present invention is small, and the consumption of tail gas treatment liquid (alkaline solution) is also reduced, thereby reducing the treatment cost, which is beneficial to environmental protection and resource conservation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural schematic diagram of an experimental gas circulation recovery and treatment system of the present invention.

[0023] Figure 2 This is a structural schematic diagram of an alkali powder filtering device in an experimental gas circulation recovery and treatment system of the present invention. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0025] like Figure 1 A preferred embodiment of a laboratory gas recycling and recovery system is shown. The system includes a laboratory gas supply device 1, a heater 2, a reactor 3, a circulation pipeline 4, and an exhaust gas absorption pipeline 5. This embodiment of the laboratory gas recycling and recovery system is used for catalyst testing gas distribution simulation experiments. In other embodiments, the system can be used for other gas distribution simulation experiments.

[0026] In the actual SCR denitrification catalytic reaction, the gases under actual flue gas conditions include NO, SO2, SO3, NH3, and air. In the catalyst detection gas distribution simulation experiment, to simulate actual flue gas conditions, multiple experimental gas supply devices 1 are used, including a NO / NH3 supply device, a SO2 supply device, a SO3 supply device, an air supply device, and a load gas (N2) supply device. The outlet of each experimental gas supply device 1 is connected to the heater 2 via an intake pipe 6. The outlet of the heater 2 is connected to the reactor 3, which is equipped with a catalyst. The outlet of the reactor 3 is connected to the circulation pipe 4 and the exhaust gas absorption pipe 5. The circulation pipe 4 and the exhaust gas absorption pipe 5 are arranged in parallel. The circulation pipe 4 is equipped with a circulation fan 7 and an alkali powder filter device 8. The gas outlet of the alkali powder filter device 8 is connected to the intake pipe 6. The exhaust gas absorption pipe 5 is equipped with a cooling device 9 and an exhaust gas absorption device 10 connected to the outlet of the cooling device 9. The cooling device 9 is provided with a spray head 901, which is connected to a water channel and uses a spray mist to cool the tail gas. The tail gas absorption device 10 is provided with an alkaline solution.

[0027] A flow control valve 11 is installed between the outlet of the experimental gas supply device 1 and the air inlet pipe 6 to control the flow of the experimental gas. A flue gas analyzer 12 and a flow meter 13 are installed on the air inlet pipe 6, and a thermometer 14 is installed on the pipe between the heater 2 and the reactor 3. The flue gas analyzer 12 monitors the gas composition in real time; the flow meter 13 monitors the gas flow in real time, allowing the flow control valve to adjust the flow of the experimental gas based on the monitored value; and the thermometer 14 monitors the gas temperature to ensure that the temperature of the gas entering the reactor 3 does not fall below the experimental design temperature.

[0028] A circulation control valve 15 is provided on the circulation pipeline 4, and an exhaust gas control valve 16 is provided on the exhaust gas absorption pipeline 5. The circulation control valve 15 can be used to open or close the circulation pipeline 4, and similarly, the exhaust gas control valve 16 can be used to open or close the exhaust gas absorption pipeline 5.

[0029] The circulation fan 7 on the circulation pipeline 4 recycles the gas at the reactor outlet. According to the design specifications, the flow velocity in the catalyst hole is 5-7 m / s, the experimental gas flow rate is 85-125 L / s, the circulation fan flow margin is 10%, and the flow rate is selected to be 138 L / s. The system resistance is <2000 Pa, the pressure head margin is 20%, the fan pressure head is 2400 Pa, and the supporting motor power is 0.8 kW.

[0030] Since the SO3 content of the gas will increase after passing through the reactor 3, the continuous accumulation of SO3 will affect the catalyst detection during the recycling of the gas. The alkali powder filter device 8 set on the circulation pipeline 4 can absorb the SO3 in the gas and filter the gas to a certain extent.

[0031] like Figure 2 As shown, the alkali powder filtering device 8 has an absorption chamber 801, in which alkali powder is provided; the top of the absorption chamber 801 of the alkali powder filtering device 8 is provided with an inwardly folded baffle 802, and a vortex mouth is formed between the folding baffle 802 and the cavity wall of the absorption chamber 801; and the angle between the folding baffle 802 and the cavity wall of the absorption chamber below is less than 145°; the vortex mouth formed between the folding baffle 802 and the cavity wall of the absorption chamber 801 can change the trajectory of some alkali powder fine particles in the airflow and form an airflow vortex, so that the alkali powder fine particles are separated from the airflow and return to the absorption chamber 801 of the alkali powder filtering device 8, thereby preventing the alkali powder from being carried out by the airflow to block the pipeline; and the angle β between the folding baffle and the cavity wall of the absorption chamber is designed to be less than 145°, which is more conducive to the formation of an airflow vortex. The gas outlet of the alkali powder filter device 8 is provided with a first turning channel 803 and a second turning channel 804. The first turning channel 803 is an inverted L-shape, connecting to the vortex outlet, while the second turning channel 804 is a straight L-shape. The first turning channel 803 and the second turning channel 804 are spliced ​​together to form a U-shaped outlet channel. The outlet width L1 of the first turning channel 803 is smaller than the outlet width L2 of the second turning channel 804. The coordination of the first turning channel 803 and the second turning channel 804 allows the finer particles carried out to be more easily deposited on the U-shaped outlet channel during the turning outflow process, further preventing the alkali powder from being carried away by the airflow. In addition, a fixed discharge port is provided at the bottom of the U-shaped outlet channel of the alkali powder filter device 8. Thus, alkali powder particles and the like deposited at the U-shaped outlet channel can be discharged through the fixed discharge port. The alkali powder discharged through the fixed discharge port can enter the tail gas absorption device 10 for treatment.

[0032] The ratio of the height h to the inner diameter Φa of the alkali powder filtering device 8 is greater than 3, which can control the suspension height of the alkali powder and prevent the alkali powder from being carried out by the air flow to a certain extent.

[0033] Furthermore, the bottom of the alkali powder filter 8 is also provided with an alkali powder outlet, which is connected to the tail gas absorption device 10. During use, the alkali powder is regularly replaced, and the replaced alkali powder can be discharged from the alkali powder outlet and then enter the tail gas absorption device 10 for treatment.

[0034] The working process of the system for catalyst experiments is as follows:

[0035] Before formal testing, unused catalyst samples were placed in Reactor 3 and aged for 36 hours by passing flue gas. During catalyst testing, parameters that needed to be controlled to simulate real flue gas conditions included temperature, NO, SO2, SO3, NH3, humidity, and oxygen content.

[0036] First, the reaction gases, including NO, SO2, SO3, NH3, and air, are configured to simulate actual flue gas conditions. A custom steam generator is also used to provide a fixed amount of water vapor to achieve the desired humidity. N2 is also used as the load gas. Various experimental gas supply devices supply air to the intake pipes. A flue gas analyzer monitors the gas composition in real time, and flow control valves are used to adjust the amount of each experimental gas introduced to ensure that the simulated gas is consistent with the design parameters.

[0037] During the formal experiment, the circulation control valve 15 was opened. Simulated gas entered heater 2 through intake pipe 6, where it heated the gas to the experimental design temperature. The simulated gas then entered reactor 3, where it reacted with the catalyst to produce a denitrification reaction. Driven by a circulating fan 7, the reacted gas entered circulation pipe 4 and then alkali powder filter 8, where the alkali powder absorbed SO₃ in the gas, reducing its concentration. The absorbed gas then entered reactor 3 for recycling. In this way, the high-temperature gas at the reactor outlet was recycled, and heater 2 only needed to replenish heat lost to maintain the reaction temperature. A thermometer 14 measured the gas temperature at the reactor inlet in real time. When the measured gas temperature was 2°C below the experimental design temperature, heater 2 was activated; when it was 2°C above, heater 2 was deactivated, significantly reducing heating energy consumption. Furthermore, the gas recycling process significantly reduced experimental gas consumption.

[0038] During the experiment, NO and NH3 react in the reactor 3, and the reaction gas needs to be replenished in real time. The concentration of environmental gases such as SO2 decreases very slowly, and it only needs to be adjusted and replenished according to the concentration test value, that is, some environmental gases (SO2, H2O, etc.) are replenished in time. The load gas (N2) does not participate in the reaction and will not decrease itself, but considering the consumption such as system leakage, it needs to be adjusted according to the flow monitoring value. The flow meter 13 on the air intake pipe can monitor the gas flow in real time, and the flue gas analyzer 12 can monitor the gas composition in real time; the flow meter 13 and the flue gas analyzer 12 can cooperate to feed back the monitoring value to the flow control valve, and the flow control valve 11 adjusts the gas intake amount for each experiment according to the monitoring value.

[0039] During the experiment, data were collected at the inlet and outlet of reactor 3 for catalyst performance testing, with a cycle of 2-3 hours. When the simulated flue gas conditions changed, data collection was resumed after stabilization for at least one hour.

[0040] At the end of the experiment, the circulation control valve 15 is closed and the exhaust control valve 16 is opened. The exhaust gas generated during the experiment enters the cooling device 9, where the spray head 901 sprays water mist to cool the exhaust gas. The cooled exhaust gas enters the exhaust gas absorption device 10, where the alkaline solution in the exhaust gas absorption device 10 purifies the exhaust gas and is discharged after meeting the standards. In addition, the alkali powder in the alkali powder filter 8 is regularly replaced and the replaced alkali powder is discharged to the exhaust gas absorption device 10. Alkali powder accumulated in the U-shaped outlet channel of the alkali powder filter 8 can also be discharged to the exhaust gas absorption device 10 through the fixed discharge port. When the waste liquid in the exhaust gas absorption device 10 accumulates to a certain amount, it is transported to the waste liquid treatment center for treatment.

[0041] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any modifications or equivalent transformations made using the contents of the present invention's description and drawings, or any direct or indirect application in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An experimental gas recycling and treatment system, characterized in that: It includes an experimental gas supply device, a heater, a reactor, a circulation pipeline and an exhaust gas absorption pipeline; the experimental gas supply device includes a NO / NH3 supply device, a SO2 supply device, a SO3 supply device, an air supply device and a load gas supply device; the reactor is a denitrification catalytic reactor; The outlet of the experimental gas supply device is connected to the heater through an air inlet pipeline, the outlet of the heater is connected to the reactor, and the outlet of the reactor is connected to the circulation pipeline and the tail gas absorption pipeline; the circulation pipeline and the tail gas absorption pipeline are arranged in parallel; a circulation fan and an alkali powder filter device are provided on the circulation pipeline; a cooling device and a tail gas absorption device connected to the outlet of the cooling device are provided on the tail gas absorption pipeline; the gas outlet of the alkali powder filter device is connected to the air inlet pipeline; The alkali powder filter device has an absorption chamber with alkali powder provided in the absorption chamber; the top of the absorption chamber of the alkali powder filter device is provided with an inwardly folded baffle, the angle between the folded baffle and the cavity wall of the absorption chamber is less than 145°, and a vortex port is formed between the folded baffle and the cavity wall of the absorption chamber; the gas outlet of the alkali powder filter device is provided with a first turning channel and a second turning channel; the first turning channel is an inverted L-shape, which is connected to the vortex port, and the second turning channel is a right L-shape, the outlet width of the first turning channel is smaller than the outlet width of the second turning channel, and the first turning channel and the second turning channel are spliced ​​into a U-shaped outlet channel.

2. The experimental gas recycling and treatment system according to claim 1, characterized in that: A flue gas analyzer and a flow meter are provided on the air intake pipeline, and a thermometer is provided on the pipeline between the heater and the reactor.

3. The experimental gas recycling and treatment system according to claim 1, characterized in that: A flow regulating valve is provided between the outlet of the experimental gas supply device and the air inlet pipeline.

4. The experimental gas recycling and treatment system according to claim 1, characterized in that: A circulation control valve is provided on the circulation pipeline, and a tail gas control valve is provided on the tail gas absorption pipeline.

5. The experimental gas recycling and treatment system according to claim 1, characterized in that: The alkali powder filtering device is provided with an alkali powder discharge port, and the alkali powder discharge port is connected to the tail gas absorption device.

6. The experimental gas recycling and treatment system according to claim 1, characterized in that: The ratio of the height to the inner diameter of the alkali powder filtering device is greater than 3.

7. The experimental gas recycling and treatment system according to claim 1, characterized in that: A fixed discharge port is provided at the bottom of the U-shaped outlet channel of the alkali powder filtering device.

8. The experimental gas recycling and treatment system according to claim 1, characterized in that: The cooling device is provided with a spray head.

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