CN115646126B - Microwave device for cracking and converting gas - Google Patents
Microwave device for cracking and converting gas Download PDFInfo
- Publication number
- CN115646126B CN115646126B CN202211406411.1A CN202211406411A CN115646126B CN 115646126 B CN115646126 B CN 115646126B CN 202211406411 A CN202211406411 A CN 202211406411A CN 115646126 B CN115646126 B CN 115646126B
- Authority
- CN
- China
- Prior art keywords
- gas
- transmitting tube
- wave
- cavity
- tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Physical Or Chemical Processes And Apparatus (AREA)
Abstract
The invention discloses a microwave device for cracking and converting gas, which comprises a shell, an inner wave-transmitting tube, a high-speed jet tube and a compression waveguide, wherein a first cavity is arranged in the shell, a plurality of air inlet tubes communicated with the first cavity are arranged on the shell, the shell is sleeved outside the inner wave-transmitting tube, the high-speed jet tube is communicated with the upper end of the inner wave-transmitting tube, the lower end of the inner wave-transmitting tube is opened, an air vent is arranged on the side wall, close to the upper end, of the inner wave-transmitting tube, of the compression waveguide, one end of the compression waveguide is arranged outside the shell and connected with the shell, the other end of the compression waveguide is connected with a microwave source, a wave-transmitting baffle is arranged at the position, close to the upper end of the inner wave-transmitting tube, of the compression waveguide. The invention provides a microwave device for cracking and converting gas, which can realize higher gas flux in a limited volume and improve the energy utilization efficiency and the gas conversion rate.
Description
Technical Field
The invention relates to the technical field of gas conversion devices, in particular to a microwave device for cracking and converting gas.
Background
Carbon dioxide is a major contributor to global warming by the global warming effect, and chemical industry, steel, coal-fired power plants and fuel automobiles are emitting huge amounts of carbon dioxide every day along with the progress of heavy industrialization in China. Microwave technology has become very popular in our daily lives. The microwave device can heat molecules (including carbon dioxide sewing) of some substances, and the microwave heating is characterized in that: the heating speed is high; the heating efficiency is high, and the electricity and the energy are saved; heating uniformly; selectively heating; instant control of the heating process, etc. In order to avoid interference with each other, the microwave frequency bands for industrial, scientific and medical use are different. Currently, only 915MHz and 2450MHz are widely used in the industrial field. The prior art can heat and crack carbon dioxide gas through microwave equipment and reform the carbon dioxide gas into carbon monoxide and oxygen, but the prior microwave device has the limitation that the size of a reaction cavity cannot be smaller than the wavelength at the frequency of the used microwaves, the frequency and the power of a microwave source limit the applicable power of the device, and the difficulty of the microwave device is how to realize higher medium flux and energy utilization efficiency in a limited volume.
Disclosure of Invention
The invention provides a microwave device for cracking and converting gas, which aims to solve the problems of low medium flux and low energy utilization efficiency of the microwave device in a limited volume in the prior art, can realize higher gas flux in the limited volume and improve the energy utilization efficiency and the gas conversion rate.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the utility model provides a microwave device for schizolysis and conversion gas, includes shell, interior wave-transmitting tube, high-speed injection pipe and compression waveguide, be equipped with first cavity in the shell, be equipped with on the shell with a plurality of intake pipe of first cavity intercommunication, the shell cover is established in the wave-transmitting tube outside, high-speed injection pipe with the upper end intercommunication of interior wave-transmitting tube, the lower extreme opening setting of interior wave-transmitting tube, be equipped with the bleeder vent on the lateral wall that interior wave-transmitting tube is close to the upper end, the compression waveguide sets up in the shell outside and the one end of compression waveguide is connected with the shell, the other end and the microwave source of compression waveguide are connected, the position that compression waveguide and shell are connected is equipped with the wave-transmitting baffle, the compression waveguide sets up the position that is close to interior wave-transmitting tube upper end, the high-speed air current that high-speed injection pipe produced produces the negative pressure in the bleeder vent position with the gas of first cavity is inhaled into interior wave-transmitting tube.
According to the technical scheme, a part of raw material gas directly enters the inner wave-transmitting tube from the high-speed injection tube, another part of raw material gas enters the first cavity from the air inlet tube, and due to Bernoulli effect, high-speed air flow sprayed out of the high-speed injection tube can form negative pressure at the position of the air holes, so that the air pressure in the inner wave-transmitting tube is far smaller than the air pressure in the first cavity, the raw material gas in the first cavity is quickly sucked into the inner wave-transmitting tube by the air pressure difference, the raw material gas is mixed with the air entering the inner wave-transmitting tube from the high-speed injection tube, microwaves in the compressed wave guide quickly heat the raw material gas in the inner wave-transmitting tube, so that the raw material gas is cracked and recombined to form product gas or product particles, the raw material gas can quickly pass through the central area and be discharged out of the inner wave-transmitting tube, overlong residence time of the heated gas in the area is avoided, and reverse reaction is effectively prevented. And the gas can be sucked from the first cavity through negative pressure, so that the flow rate of the raw material gas in the area where the microwave energy is most concentrated is increased, the raw material gas in the first cavity can cool the inner wave-transmitting tube, and meanwhile, the raw material gas can be preheated by the compressed waveguide when passing through the compressed waveguide position. The field intensity of microwaves transmitted by the compressed waveguide from the microwave source is not uniformly distributed on the radial position of the shell, but is maximum on the central position of the shell, the field intensity is weakened towards two sides in sequence, the radial width of the microwave field is equal to the wavelength of the microwaves, the inner wave-transmitting tube is arranged in the first cavity, so that raw material gas sprayed by the high-speed spraying tube passes through a high-field intensity region and does not pass through an outer side region with low field intensity, the raw material gas passing through the high-field intensity region is rapidly heated and fully cracked, the conversion rate of the raw material gas is improved, the first cavity is arranged at the outer side of the inner wave-transmitting tube and can coincide with the low-field intensity region of the microwaves, the energy of the low-field intensity region is fully utilized to preheat part of the raw material gas, the energy utilization rate is improved, the generated heat can be taken away by the raw material gas in the first cavity, the shell and the inner wave-transmitting tube are cooled, and damage caused by overhigh temperature is avoided. In order to prevent gas from entering the compression waveguide and the microwave system, a wave-transmitting baffle is arranged at the connection position of the compression waveguide and the shell, and the wave-transmitting baffle is made of wave-transmitting materials and can transmit microwaves, so that the microwaves can enter the first cavity.
Preferably, the wavelength of the microwave in the compressed waveguide is lambda, the inner diameter of the inner wave-transmitting tube is d2, and d2 is more than or equal to 0.5 lambda and less than or equal to 0.8 lambda; the inner diameter of the shell is d1, and lambda is not less than d1 and not more than 1.1lambda. The d2 is more than or equal to 0.5λ and less than or equal to 0.8λ, so that the inner wave-transmitting tube is positioned in a central high field strength region of the microwave field, the high field strength region is fully utilized to carry out high-temperature cracking on gas, the gas conversion rate is improved, the inner diameter of the inner wave-transmitting tube is not too small, and the gas throughput in the inner wave-transmitting tube is ensured. The lambda is less than or equal to d1 and less than or equal to 1.1lambda, the radial width of the microwave field intensity in the shell is approximately equal to the wavelength of the microwaves, so that the shell can just contain the whole microwave field intensity, and the microwave energy is fully utilized.
Preferably, the air inlet pipe is arranged at a position close to the lower end of the inner wave-transmitting pipe. Raw material gas entering through the air inlet pipe can pass through the first cavity from bottom to top, so that the raw material gas is fully contacted with the inner wave-transmitting tube, the inner wave-transmitting tube is radiated, and the inner wave-transmitting tube is prevented from being damaged due to overhigh temperature.
Preferably, the microwave device further comprises an outer wave-transmitting tube, the outer wave-transmitting tube is arranged in the first cavity, the outer wave-transmitting tube is sleeved outside the inner wave-transmitting tube, the air inlet tube is arranged at a position close to the upper end of the outer wave-transmitting tube, a first air channel is formed between the outer wave-transmitting tube and the inner wave-transmitting tube, a second air channel is formed between the outer shell and the outer wave-transmitting tube, the first air channel is communicated with the second air channel, the communicating position is close to the lower end of the inner wave-transmitting tube, air entering the air inlet tube passes through the second air channel from top to bottom and enters the first air channel, and air entering the first air channel passes through the first air channel from bottom to top and enters the inner wave-transmitting tube through the air holes.
According to the technical scheme, a part of raw material gas enters the first cavity from the air inlet pipe, then the raw material gas passes through the second gas channel from top to bottom to cool the outer shell and the outer wave-transmitting pipe, then the gas entering the first gas channel passes through the outer wave-transmitting pipe and the inner wave-transmitting pipe of the first gas channel from bottom to top to cool, meanwhile, the raw material gas is preheated by the compressed waveguide when passing through the position close to the compressed waveguide, then the raw material gas enters the air hole and is mixed with high-speed air flow sprayed by the high-speed spray pipe, microwaves transmitted by the compressed waveguide are heated fast in the inner wave-transmitting pipe, so that the raw material gas is cracked and recombined to form product gas, and the product gas is discharged out of the inner wave-transmitting pipe. The temperature of the gas is highest at the position close to the compressed waveguide, the temperature of the equipment is also highest at the position, through arranging the gas inlet pipe at the position close to the upper end of the outer wave-transmitting pipe, the low-temperature gas just entering the first cavity can rapidly cool the high-temperature position, the cooling effect is improved, and the length of the gas cooling channel is increased by arranging the first gas channel and the second gas channel, the contact area between the equipment and the raw gas is increased, and the cooling effect is further improved.
Preferably, a spiral gas distributor is arranged in the first cavity, the spiral gas distributor is arranged between the gas inlet pipe and the second gas channel, and guide blades are arranged on the spiral gas distributor so that gas flowing through the spiral gas distributor flows spirally along the axial direction. The structure can enable the raw material gas entering the second gas channel to flow spirally along the axial direction of the spiral air inlet distributor, and the spirally flowing gas can have good cooling protection effect on the side walls of the outer shell and the outer wave-transmitting tube.
Preferably, the plurality of air inlet pipes are arranged along the tangential direction of the housing, so that the air enters the first cavity along the tangential direction of the housing to form an axially spirally flowing air flow. The structure can enable gas entering the first cavity to flow spirally along the axial direction of the shell, and good cooling protection effect is achieved on the side walls of the shell and the outer wave-transmitting tube.
Preferably, the number of the compression waveguides is a plurality, the plurality of compression waveguides are circumferentially distributed on the outer side of the shell, and the plurality of compression waveguides are arranged on the same axial position of the shell; the compression waveguide is disposed tangentially to the housing. The frequency and the power of the microwave source limit the applicable power of the microwave device, the plurality of compressed waveguides are arranged on the same axial position of the shell, the microwave intensities transmitted by the plurality of compressed waveguides can be overlapped on the same position, the problem of insufficient microwave power can be effectively solved, and the number of the input microwave sources can be further increased when necessary for improving the overall required power. Microwave energy is introduced into the upper portion of the first cavity by the tangential arrangement of the compressed waveguide on the housing such that the fundamental waveguide mode in the compressed waveguide is converted to a TE11 mode within the cavity. The benefit of this TE11 mode configuration is that the energy distribution within the cavity is greatest along the axial flow line.
Preferably, the shell is internally provided with a second cavity, the second cavity is arranged below the first cavity and is separated by a separation plate, the lower end of the inner wave-transmitting tube passes through the separation plate and is communicated with the second cavity, the shell is provided with an air outlet tube, one end of the air outlet tube is arranged in the second cavity, the other end of the air outlet tube is communicated with the outside of the second cavity, a carbon particle bed layer formed by stacking carbon particles is arranged in the second cavity, and gas in the inner wave-transmitting tube is discharged out of the shell through the air outlet tube after passing through the carbon particle bed layer.
In the technical scheme, the carbon particle bed layer has the effects of adsorbing and filtering dust-containing gas, and reduces the dust content at the bottom gas outlet. When the reaction of the raw material gas is incomplete, the gas entering the second cavity can further react with the carbon particle bed layer to generate product gas, so that the conversion rate of the microwave device to the gas is increased.
Preferably, the second cavity is internally provided with a protective cover, the upper end of the protective cover is closed, the lower end of the protective cover is opened and arranged in the carbon particle bed, the lower end of the protective cover is communicated with the carbon particle bed through a filter screen, and one end of an air outlet pipe extends into the protective cover. The structure can avoid the air outlet pipe to be directly arranged in the carbon particle bed layer, and avoid the carbon particles to be discharged through the air outlet pipe.
Preferably, the outer wall of the upper end of the protective cover is a conical surface, the tip end of the conical surface faces the inner wave-transmitting tube, a gas distribution plate is arranged on the outer side close to the lower end of the conical surface, a plurality of through holes are formed in the gas distribution plate, and the carbon particle bed layer is arranged below the gas distribution plate. The conical surface and the gas distribution plate can guide the gas to uniformly flow downwards, reduce the flow velocity, reduce the impact of the gas on the carbon particle bed, enable the gas which does not complete the reaction to fully contact with the carbon particles and further react, and improve the conversion rate of the gas.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a second schematic diagram of the structure of the present invention;
FIG. 3 is a schematic diagram III of the structure of the present invention;
fig. 4 is a schematic diagram of the structure of the present invention.
In the figure: the device comprises a shell 1, a first cavity 1.1, a second cavity 1.2, a partition plate 1.3, a cooling cavity 1.4, an outer wave-transmitting tube 2, an inner wave-transmitting tube 3, an air vent 3.1, a high-speed injection tube 4, a Laval nozzle 4.1, a compression waveguide 5, an air inlet pipe 6, a wave-transmitting partition plate 7, a first air channel 8, a second air channel 9, a spiral air distributor 10, guide vanes 10.1, an air outlet pipe 11, a carbon particle bed layer 12, a protective cover 13, a conical surface 13.1, a gas distribution plate 14, a through hole 14.1, a filter screen 15, a filling port 16, a cooling inlet 17 and a cooling outlet 18.
Description of the embodiments
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," "counterclockwise," etc. indicate or are based on the orientation or positional relationship shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention.
The invention relates to the splitting of gases in the plasma state by means of high energy intensity by means of the connection of one or more microwave sources. The microwave plasma and the catalyst can also be combined to accelerate the cracking reaction. Plasmas are composed of ions, electrons and neutral particles and are generally classified into high and low temperature states. The fact that the electron temperature is much higher than the gas temperature is commonly referred to as low temperature plasma. The excitation energy of the low temperature plasma is 1-10eV, and vibration should be used as the main mode of energy excitation in order to avoid unnecessary heat loss during the plasma generation. At the same time, the rapid passage of gas through the plasma region and rapid chilling are important means for effectively preventing the occurrence of reverse reaction. And sufficient gas throughput is a necessary condition to ensure industrial mass production.
Example 1:
as shown in fig. 1 and fig. 2, a microwave device for cracking and converting gas includes a housing 1, an inner wave-transmitting tube 3, a high-speed injection tube 4 and a compression waveguide 5, wherein a first cavity 1.1 is arranged in the housing 1, a plurality of air inlet tubes 6 communicated with the first cavity 1.1 are arranged on the housing 1, the housing 1 is sleeved outside the inner wave-transmitting tube 3, the high-speed injection tube 4 is communicated with the upper end of the inner wave-transmitting tube 3, the lower end of the inner wave-transmitting tube 3 is provided with an opening, the side wall, close to the upper end, of the inner wave-transmitting tube 3 is provided with an air vent 3.1, one end of the compression waveguide 5 is connected with the housing 1, the other end of the compression waveguide 5 is connected with a microwave source, a wave-transmitting baffle 7 is arranged at the position, close to the upper end of the inner wave-transmitting tube 3, and the high-speed air flow generated by the high-speed injection tube generates negative pressure at the air vent position to suck the gas of the first cavity into the inner wave-transmitting tube.
In the above technical scheme, the shell 1 is made of metal, so that microwaves can be isolated, and the air plays a certain role in protection. The compressed waveguide 5 has a variable cross-section structure, and is composed of a front part with the largest longitudinal cross-section area, a middle part with the largest longitudinal cross-section area and a rear part with the smallest longitudinal cross-section area. The variable cross-section structure further improves the microwave field intensity of the rear center, the microwave field intensity of the rear center is highest in the resonant cavity, and ionization discharge can be generated without ignition. A plurality of adjusting pins are arranged on the side wall of the front part of the compression waveguide 5. The microwave frequency of the microwave source is 915MHz or 2.45GHz. The raw material gas of the microwave device can be carbon dioxide, methane, ammonia and other gases.
In the above technical scheme, a part of raw material gas directly enters the inner wave-transmitting tube 3 from the high-speed injection tube 4, another part of raw material gas enters the first cavity 1.1 from the air inlet tube 6, and due to the bernoulli effect, the high-speed air flow sprayed out from the high-speed injection tube 4 can form negative pressure at the position of the air hole 3.1, so that the air pressure in the inner wave-transmitting tube 3 is far smaller than the air pressure in the first cavity 1.1, the raw material gas in the first cavity 1.1 is quickly sucked into the inner wave-transmitting tube 3 by the air pressure difference, and is mixed with the air entering the inner wave-transmitting tube 3 from the high-speed injection tube 4, microwaves in the compression waveguide 5 quickly heat the raw material gas in the inner wave-transmitting tube 3, so that the raw material gas is cracked and recombined to form product gas or product particles, the raw material gas can quickly pass through the central area and be discharged out of the inner wave-transmitting tube 3, the heated gas is prevented from staying in the area for too long time, and the reverse reaction is effectively prevented. And the gas can be sucked from the first cavity 1.1 through negative pressure, so that the flow rate of the raw material gas in the region where the microwave energy is most concentrated is increased, the raw material gas in the first cavity 1.1 can cool the inner wave-transmitting tube 3, and meanwhile, the raw material gas can be preheated by the compressed waveguide 5 when passing through the compressed waveguide 5. The field intensity of the microwaves transmitted by the compressed waveguide 5 from the microwave source is not uniformly distributed on the radial position of the shell 1, but is maximum on the central position of the shell 1, the field intensity is weakened towards two sides in sequence, the radial width of the microwave field is equal to the wavelength of the microwaves, the inner wave-transmitting tube 3 is arranged in the first cavity 1.1, the raw material gas sprayed by the high-speed spraying tube 4 can pass through a high field intensity region and not pass through an outer region with low field intensity, the raw material gas passing through the high field intensity region is rapidly heated and fully cracked, the conversion rate of the raw material gas is improved, the first cavity 1.1 is arranged outside the inner wave-transmitting tube 3, the energy of the low field intensity region is fully utilized to preheat part of the raw material gas, the energy utilization rate is improved, the raw material gas in the first cavity 1.1 can also take away generated heat, the outer shell 1 and the inner wave-transmitting tube 3 are cooled, and the damage caused by the temperature is avoided. In order to prevent gas from entering the compression waveguide 5 and the microwave system, a wave-transmitting baffle 7 is arranged at the connection position of the compression waveguide 5 and the shell 1, and the wave-transmitting baffle 7 is made of wave-transmitting material and can transmit microwaves, so that the microwaves can enter the first cavity 1.1.
Be equipped with second cavity 1.2 in the shell 1, second cavity 1.2 sets up in first cavity 1.1 below and both separate through division board 1.3, interior wave-transmitting tube 3's lower extreme passes division board 1.3 and communicates with second cavity 1.2, be equipped with outlet duct 11 on the shell 1, the one end setting of outlet duct 11 is in second cavity 1.2, the other end and the outside intercommunication of second cavity 1.2 of outlet duct 11 are equipped with in the second cavity 1.2 and pile up the carbon granule bed 12 that forms by the carbon granule, and the gas in the interior wave-transmitting tube 3 is discharged shell 1 by outlet duct 11 after passing through carbon granule bed 12.
In the above technical solution, the carbon particle bed 12 has the effects of adsorbing and filtering the dust-containing gas, and reduces the dust content at the bottom gas outlet. When the reaction of the raw material gas is incomplete, the gas entering the second cavity 1.2 can further react with the carbon particle bed 12 to generate product gas, so that the conversion rate of the microwave device to the gas is increased.
The second cavity 1.2 is internally provided with a protective cover 13, the upper end of the protective cover 13 is closed, the lower end of the protective cover 13 is opened and arranged in the carbon particle bed 12, the lower end of the protective cover 13 is communicated with the carbon particle bed 12 through a filter screen 15, and one end of an air outlet pipe 11 extends into the protective cover 13. The outer wall of the upper end of the protective cover 13 is a conical surface 13.1, the tip end of the conical surface 13.1 faces the inner wave-transmitting tube 3, a gas distribution plate 14 is arranged on the outer side close to the lower end of the conical surface 13.1, a plurality of through holes 14.1 are formed in the gas distribution plate 14, and the carbon particle bed 12 is arranged below the gas distribution plate 14. The second chamber 1.2 is provided with filling openings 16, which filling openings 16 are arranged below the gas distribution plate 14. The outside of second cavity 1.2 is equipped with the cooling cavity 1.4 that is equipped with the isolated setting of second cavity 1.2, be equipped with cooling inlet 17 and cooling outlet 18 on the cooling cavity 1.4. The structure can avoid the air outlet pipe 11 to be directly arranged in the carbon particle bed layer 12, and avoid the carbon particles to be discharged through the air outlet pipe 11. The conical surface 13.1 and the gas distribution plate 14 can guide the gas to flow downwards uniformly, reduce the flow rate, reduce the impact of the gas on the carbon particle bed 12, enable the gas which does not complete the reaction to fully contact with the carbon particles and further react, and improve the conversion rate of the gas. The carbon particle bed 12, as a feedstock for increasing gas conversion, may be replenished through the fill port 16 as the reaction proceeds to decrease gradually. The cooling medium enters from the cooling inlet 17 and flows out from the cooling outlet 18, so that the lower half of the device can be cooled.
The wavelength of the microwaves in the compressed waveguide 5 is lambda, the inner diameter of the inner wave-transmitting tube 3 is d2, d2 is more than or equal to 0.5 lambda and less than or equal to 0.8 lambda, and the optimal value is d2=0.65 lambda. The d2 is more than or equal to 0.5λ and less than or equal to 0.8λ, so that the inner wave-transmitting tube 3 is located in a central high field strength region of the microwave field, the high field strength region is fully utilized to carry out high-temperature cracking on gas, the gas conversion rate is improved, the inner diameter of the inner wave-transmitting tube 3 is not too small, and the gas throughput in the inner wave-transmitting tube 3 is ensured.
The inner diameter of the shell 1 is d1, lambda is less than or equal to d1 and less than or equal to 1.1lambda, and the optimal value is d1=lambda. The radial width of the microwave field intensity in the shell 1 is approximately equal to the wavelength of microwaves, so that the shell 1 can just contain the whole microwave field intensity and fully utilize the microwave energy.
The number of the compression waveguides 5 is four, the four compression waveguides 5 are circumferentially distributed on the outer side of the housing 1, and the four compression waveguides 5 are arranged on the same axial position of the housing 1. The frequency and the power of the microwave source limit the applicable power of the microwave device, the plurality of compression waveguides 5 are arranged on the same axial position of the shell 1, the microwave intensities transmitted by the plurality of compression waveguides 5 can be overlapped on the same position, the problem of insufficient microwave power can be effectively solved, and the number of the input microwave sources can be further increased when necessary for improving the power required by the whole.
The compression waveguide 5 is arranged tangentially to the housing 1. By the tangential arrangement of the compressed waveguide 5 on the housing 1 microwave energy is introduced into the upper part of the first cavity 1.1 such that the fundamental waveguide mode in the compressed waveguide 5 is converted into TE11 mode in the cavity. The benefit of this TE11 mode configuration is that the energy distribution within the cavity is greatest along the axial flow line. (for a detailed explanation of TE11 mode, reference is made to the paper: high-power curved circular waveguide TE01-TM11 mode transformation analysis-author: li Changqing, self-evident, new).
The outlet end of the high-speed jet pipe 4 is provided with a Laval nozzle 4.1 so that subsonic gas in the high-speed jet pipe 4 passes through the Laval nozzle 4.1 to form supersonic gas jet. The Laval nozzle 4.1 can further increase the gas flow rate at the outlet end of the high-speed jet pipe 4, so that the gas flow reaches supersonic speed, the high-speed gas flow can avoid the overlong residence time of the heated gas in the area, and meanwhile, the Laval nozzle 4.1 can reduce the pressure in the inner wave-transmitting pipe 3 and increase the gas sucked through the ventilation holes 3.1.
Example 2:
as shown in fig. 1 and 2, on the basis of embodiment 1, the intake pipe 6 is provided at a position near the lower end of the inner wave-transmitting tube 3. So that the gas enters the first chamber 1.1 tangentially to the housing 1 to form an axially helically flowing gas flow. Raw material gas entering through the air inlet pipe 6 can pass through the first cavity 1.1 from bottom to top, so that the raw material gas is fully contacted with the inner wave-transmitting tube 3, the inner wave-transmitting tube 3 is radiated, and the inner wave-transmitting tube 3 is prevented from being damaged due to overhigh temperature. The air inlet pipes 6 are arranged along the tangential direction of the shell 1, so that air entering the first cavity 1.1 can spirally flow along the axial direction of the shell 1, and a good cooling protection effect is achieved on the side walls of the shell 1 and the outer wave-transmitting tube 2.
Example 3:
as shown in fig. 3 and fig. 4, on the basis of embodiment 1, the microwave device further includes an outer wave-transmitting tube 2, the outer wave-transmitting tube 2 is disposed in the first cavity 1.1, the outer wave-transmitting tube 2 is sleeved outside the inner wave-transmitting tube 3, the air inlet tube 6 is disposed at a position near the upper end of the outer wave-transmitting tube 2, a first air channel 8 is formed between the outer wave-transmitting tube 2 and the inner wave-transmitting tube 3, a second air channel 9 is formed between the outer shell 1 and the outer wave-transmitting tube 2, the first air channel 8 is communicated with the second air channel 9 and the communication position is near the lower end of the inner wave-transmitting tube 3, air entering the air inlet tube 6 passes through the second air channel 9 from top to bottom and enters the first air channel 8, and air entering the first air channel 8 passes through the first air channel 8 from bottom to top and enters the inner wave-transmitting tube 3 through the air vent 3.1.
In the above technical solution, the outer wave-transmitting tube 2 and the inner wave-transmitting tube 3 may be integrally made of a material that can be penetrated by microwaves, for example, a quartz material, or a portion that is close to the compressed waveguide 5 may be made of a material that can be penetrated by microwaves, and the rest portions are made of other materials. Part of raw material gas enters the first cavity 1.1 from the air inlet pipe 6, then the raw material gas passes through the second gas channel 9 from top to bottom to cool the shell 1 and the outer wave-transmitting tube 2, then the gas entering the first gas channel 8 passes through the outer wave-transmitting tube 2 and the inner wave-transmitting tube 3 of the first gas channel 8 from bottom to top, meanwhile, the raw material gas is preheated by the compressed wave-transmitting tube 5 when passing through the position close to the compressed wave-transmitting tube 5, then the raw material gas enters the air hole 3.1, the inner wave-transmitting tube 3 is mixed with high-speed air flow sprayed by the high-speed spray tube 4, microwaves transmitted by the compressed wave-transmitting tube 5 are quickly heated in the inner wave-transmitting tube 3, so that the raw material gas is cracked and recombined to form product gas, and the inner wave-transmitting tube 3 is discharged. The temperature of the gas is highest at the position close to the compression waveguide 5, the temperature of the equipment is also highest at the position, the low-temperature gas just entering the first cavity 1.1 can be firstly and rapidly cooled at the high-temperature position by arranging the gas inlet pipe 6 at the position close to the upper end of the outer wave-transmitting pipe 2, the cooling effect is increased, the length of the gas cooling channel is increased by arranging the first gas channel 8 and the second gas channel 9, the contact area between the equipment and raw gas is increased, and the cooling effect is further increased.
A spiral gas distributor 10 is arranged in the first cavity 1.1, the spiral gas distributor 10 is arranged between the gas inlet pipe 6 and the second gas channel 9, and guide vanes 10.1 are arranged on the spiral gas distributor 10 so that gas flowing through the spiral gas distributor 10 flows spirally along the axial direction. The structure can enable the raw material gas entering the second gas channel 9 to flow spirally along the axial direction of the spiral air inlet distributor, and the spirally flowing gas can have good cooling protection effect on the side walls of the shell 1 and the outer wave-transmitting tube 2.
The several inlet pipes 6 are arranged tangentially to the housing 1 so that the gas enters the first chamber 1.1 tangentially to the housing 1 to form an axially helically flowing gas flow. The structure can enable gas entering the first cavity 1.1 to flow spirally along the axial direction of the shell 1, and has good cooling protection effect on the side walls of the shell 1 and the outer wave-transmitting tube 2.
Example 4:
on the basis of example 1, when the microwave device of the present invention is used for decomposition of carbon dioxide, the main chemical reactions are as follows:
CO 2 - CO + O， ΔH = 5.5 eV，
C+CO 2 =2CO
CO at normal pressure 2 The gas enters a cavity part through a gas pipe which is tangentially arranged, enters a microwave plasma region through a vent hole 3.1 on an inner wave-transmitting tube 3, and high-energy electrons are generated by excitation of microwave plasma, and the electrons are in contact with CO 2 CO in the collision of (a) 2 The conversion will increase continuously with increasing temperature, reaching 100% at 4000K-4500K. The CO and O after pyrolysis can react reversibly with the decrease of temperature. When the cracked mixed gas flows into the bed 12 filled with carbon particles, the following reaction occurs again:
C+O->CO
2C+O 2 ->2CO
C+CO 2 ->2CO
after passing through the bed 12 of carbon particles, the CO is not converted to complete 2 And CO produced by the reverse reaction 2 And CO is generated again, and 100% conversion rate is finally realized. CO at this time 2 Has been totally converted to CO and exits the device along outlet pipe 11.
Example 5:
the invention is used for the dry reforming reaction of carbon dioxide and methane into synthesis gas on the basis of example 1, and the main chemical reactions are as follows:
CO2+CH4- >2CO+2H2; in this embodiment, two gases may be introduced into the apparatus from the high-velocity injection pipe 4 and the gas inlet pipe 6, respectively, while catalyst particles are placed in the bottom carbon particle bed 12 layer to improve the reaction efficiency.
Claims (9)
1. The microwave device for cracking and converting gas is characterized by comprising a shell, an inner wave-transmitting tube, a high-speed injection tube and a compression waveguide, wherein a first cavity is arranged in the shell, a plurality of air inlet tubes communicated with the first cavity are arranged on the shell, the shell is sleeved outside the inner wave-transmitting tube, the high-speed injection tube is communicated with the upper end of the inner wave-transmitting tube, the lower end of the inner wave-transmitting tube is provided with an opening, the side wall, close to the upper end, of the inner wave-transmitting tube is provided with an air vent, the compression waveguide is arranged outside the shell, one end of the compression waveguide is connected with the shell, the other end of the compression waveguide is connected with a microwave source, a wave-transmitting baffle is arranged at the position, close to the upper end of the inner wave-transmitting tube, of the compression waveguide is arranged, and high-speed air flow generated by the high-speed injection tube generates negative pressure at the air vent position to suck the gas of the first cavity into the inner wave-transmitting tube;
the wavelength of the microwaves in the compressed waveguide is lambda, the inner diameter of the inner wave-transmitting tube is d2, and d2 is more than or equal to 0.5 lambda and less than or equal to 0.8 lambda; the inner diameter of the shell is d1, and lambda is not less than d1 and not more than 1.1lambda;
the outlet end of the high-speed jet pipe is provided with a Laval nozzle, so that subsonic gas in the high-speed jet pipe passes through the Laval nozzle to form supersonic gas jet.
2. A microwave apparatus for splitting and converting a gas as defined in claim 1, wherein said air inlet pipe is disposed adjacent to the lower end of the inner wave-transparent tube.
3. The microwave apparatus for cracking and converting gas according to claim 1, further comprising an outer wave-transmitting tube, wherein the outer wave-transmitting tube is disposed in the first cavity, the outer wave-transmitting tube is sleeved outside the inner wave-transmitting tube, the air inlet tube is disposed at a position close to the upper end of the outer wave-transmitting tube, a first gas channel is formed between the outer wave-transmitting tube and the inner wave-transmitting tube, a second gas channel is formed between the outer shell and the outer wave-transmitting tube, the first gas channel is communicated with the second gas channel and is located close to the lower end of the inner wave-transmitting tube, the gas entering the air inlet tube passes through the second gas channel from top to bottom and enters the first gas channel, and the gas entering the first gas channel passes through the first gas channel from bottom to top and enters the inner wave-transmitting tube through the air vent.
4. A microwave apparatus for splitting and converting gas as defined in claim 3, wherein a spiral gas distributor is provided in said first chamber, the spiral gas distributor being provided between the gas inlet pipe and the second gas passage, and guide vanes are provided on said spiral gas distributor to cause the gas flowing through the spiral gas distributor to flow spirally in the axial direction.
5. A microwave device for splitting and converting gas as recited in claim 1, wherein said plurality of inlet tubes are arranged tangentially to the housing such that gas enters the first cavity tangentially to the housing to form an axially helically flowing gas stream.
6. A microwave device for splitting and converting a gas as defined in claim 1, wherein the number of said compression waveguides is plural, the plural compression waveguides are circumferentially distributed on the outside of the housing, and the plural compression waveguides are disposed at the same axial position of the housing; the compression waveguide is disposed tangentially to the housing.
7. The microwave device for cracking and converting gas according to claim 1, wherein a second cavity is provided in the housing, the second cavity is provided below the first cavity and is separated by a partition plate, the lower end of the inner wave-transmitting tube passes through the partition plate and is communicated with the second cavity, the housing is provided with an air outlet tube, one end of the air outlet tube is provided in the second cavity, the other end of the air outlet tube is communicated with the outside of the second cavity, a carbon particle bed formed by stacking carbon particles is provided in the second cavity, and the gas in the inner wave-transmitting tube is discharged out of the housing through the air outlet tube after passing through the carbon particle bed.
8. The microwave apparatus for cracking and converting gas according to claim 7, wherein a protective cover is provided in the second cavity, the upper end of the protective cover is closed, the lower end of the protective cover is opened and arranged in the carbon particle bed, the lower end of the protective cover is communicated with the carbon particle bed through a filter screen, and one end of the air outlet pipe extends into the protective cover.
9. The microwave apparatus for cracking and converting gas according to claim 8, wherein the outer wall of the upper end of the protective cover is a conical surface, the tip of the conical surface faces the inner wave-transmitting tube, a gas distribution plate is arranged on the outer side close to the lower end of the conical surface, a plurality of through holes are formed in the gas distribution plate, and the carbon particle bed layer is arranged below the gas distribution plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211406411.1A CN115646126B (en) | 2022-11-10 | 2022-11-10 | Microwave device for cracking and converting gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211406411.1A CN115646126B (en) | 2022-11-10 | 2022-11-10 | Microwave device for cracking and converting gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115646126A CN115646126A (en) | 2023-01-31 |
| CN115646126B true CN115646126B (en) | 2023-08-01 |
Family
ID=85021469
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211406411.1A Active CN115646126B (en) | 2022-11-10 | 2022-11-10 | Microwave device for cracking and converting gas |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115646126B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201301341Y (en) * | 2008-11-04 | 2009-09-02 | 乐培界 | Microwave-plasma experimental facility |
| CN112383997A (en) * | 2020-10-05 | 2021-02-19 | 四川大学 | High-power microwave plasma pulverized coal cracking device |
| CN113244866A (en) * | 2021-05-14 | 2021-08-13 | 昆明理工大学 | Device and method for synthesizing light hydrocarbon through microwave-assisted gas catalysis |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1239445C (en) * | 2003-11-07 | 2006-02-01 | 中国科学院金属研究所 | Apparatus and process for producing acetylene by low-temperature plasmochemical pyrolysis of natural gas |
| CN201230400Y (en) * | 2008-04-24 | 2009-04-29 | 大连海事大学 | Atmosphere pressure microwave plasma producing device |
| WO2014153570A2 (en) * | 2013-03-15 | 2014-09-25 | Transtar Group, Ltd | New and improved system for processing various chemicals and materials |
| CN205760527U (en) * | 2016-05-27 | 2016-12-07 | 广东新优威印刷装备科技有限公司 | A kind of device of microwave cracking harmful gas |
| CN210386924U (en) * | 2018-12-25 | 2020-04-24 | 四川大学 | Medical waste treatment device based on microwave |
| CN212166996U (en) * | 2020-02-14 | 2020-12-18 | 陈勇 | Plasma formula tail gas processing apparatus based on microwave |
| CN111203164B (en) * | 2020-02-23 | 2024-01-23 | 李容毅 | Gas phase reaction buffer chamber based on atmospheric pressure microwave plasma torch |
-
2022
- 2022-11-10 CN CN202211406411.1A patent/CN115646126B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201301341Y (en) * | 2008-11-04 | 2009-09-02 | 乐培界 | Microwave-plasma experimental facility |
| CN112383997A (en) * | 2020-10-05 | 2021-02-19 | 四川大学 | High-power microwave plasma pulverized coal cracking device |
| CN113244866A (en) * | 2021-05-14 | 2021-08-13 | 昆明理工大学 | Device and method for synthesizing light hydrocarbon through microwave-assisted gas catalysis |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115646126A (en) | 2023-01-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5303451B2 (en) | Hydrogen production | |
| CN102363521B (en) | Vehicle-mounted microwave low-temperature plasma reformer system for online hydrogen production | |
| EP1797746B1 (en) | Microwave plasma apparatus with vorticular gas flow | |
| EP2606003B1 (en) | An apparatus, a system and a method for producing hydrogen | |
| US20120034135A1 (en) | Plasma reactor | |
| EP3075817A1 (en) | Process and system for coupling pressurized pyrolysis of biomasses | |
| CN115646126B (en) | Microwave device for cracking and converting gas | |
| US20210086158A1 (en) | Microwave enhancement of chemical reactions | |
| RU2170617C2 (en) | Versatile counterflow jet unit for high-temperature processing of raw material | |
| CN218741110U (en) | Microwave device for converting gas | |
| JP2527150B2 (en) | Microwave thermal plasma torch | |
| CN115557466B (en) | Device for producing hydrogen through pyrolysis | |
| CN219079102U (en) | Device for producing hydrogen through pyrolysis | |
| CN213417007U (en) | Plasma fluidized bed device | |
| JP2023545718A (en) | plasma gas reactor | |
| CN109455705A (en) | A kind of system by purifying and light microwave reduction prepares graphene | |
| CN103030112A (en) | Vehicle mounted microwave low temperature plasma reformer system for online hydrogen production | |
| CN212151638U (en) | Fumed silica production system | |
| CN114874801B (en) | Microwave fluidization fast pyrolysis method for granular fuel | |
| CN103011076A (en) | Vehicle-mounted microwave low-temperature plasma reformer system for online hydrogen production | |
| JPH03214600A (en) | Microwave heated plasma reaction device | |
| JP7202749B1 (en) | Fuel gas generator and method | |
| CN211864967U (en) | Gas phase reaction buffer chamber based on atmospheric pressure microwave plasma torch | |
| CN118572163A (en) | Ammonia-hydrogen fuel cell power generation system | |
| CN117065689A (en) | Microwave plasma CO for product circulation separation 2 Cracking device and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |