CN104474886B - Method for photocatalytic degradation of waste gas by electrodeless excimer lamp - Google Patents

Abstract

The invention discloses a method for catalyzing and degrading waste gas by light of electrodeless excimer lights. The reactor used includes three layers of quartz medium layers, inner electrodes, outer electrodes and a high-voltage power supply. The three-layer quartz medium layer includes a coaxial first quartz tube, a second quartz tube and a third quartz tube arranged sequentially from inside to outside; the inner cavity of the first quartz tube is the reaction zone of zone III; the second A closed annular cavity is formed between the quartz tube and the first quartz tube, which is used as a gas to fill zone II; a zone I reaction zone is formed between the third quartz tube and the second quartz tube. When photocatalytically degrading exhaust gas, the gas filled with zone II is excited to generate excimer ultraviolet light, which radiates in the direction of zone I reaction zone and zone III reaction zone, and the exhaust gas to be degraded all passes through zone I reaction zone or all passes through zone III reaction Zone or shunt flow into zone I reaction zone and zone III reaction zone, and is degraded under the action of excimer ultraviolet radiation.

Description

Method for catalytic degradation of waste gas by lightless excimer light

This application is a divisional application of the invention patent application with the application number 201310089087.X and the application date is March 20, 2013, and the invention name is "device and method for catalytic degradation of exhaust gas by non-polar excimer light".

technical field

The invention relates to the field of waste gas degradation, in particular to a method for catalytically degrading waste gas by an electrodeless excimer light.

Background technique

Ultraviolet light source has been widely used in the fields of microelectronics, medicine, chemical industry, sanitation and environmental protection, and has become a basic and key technology. All of the above applications require the light source to have a narrow radiation spectrum and a certain radiation intensity. For traditional medium and high-pressure mercury lamps, the radiation spectrum has a wide range of wavelengths (from the ultraviolet region to the visible region), and the luminous efficiency of ultraviolet light at the required wavelength is low; low-pressure mercury lamps and inert gas lamps can radiate narrow-band ultraviolet spectra, but their light The intensity is relatively weak, which affects the corresponding photochemical reaction rate; although the laser light source can radiate high intensity and narrow spectrum, the beam spot size is small and expensive. The non-polar excimer ultraviolet light source has become a novel high-efficiency incoherent light source because of its strong radiation, narrow radiation spectrum, high photoelectric conversion efficiency, strong plasticity, and relatively low price.

Traditional light sources generally have electrodes. Due to the existence of electrodes in the lamp, a series of problems have been caused: short life, long ignition time and stable time, small selection range of electrode materials and luminescent substances, less shape change, and utilization of light radiation. Low rate and complex external circuit.

Compared with the traditional extreme ultraviolet light source, the electrodeless excimer ultraviolet lamp has no electrodes in the lamp tube, and the selection range of luminescent substances is greatly expanded, and ultraviolet light wavelengths that cannot be obtained by traditional ultraviolet lamps can be obtained. The lamp can be filled with different substances according to requirements, and emits radiation ranging from vacuum ultraviolet to long-wave ultraviolet. The radiation power is strong and the light efficiency is high.

Since the 1980s, researches on electrodeless excimer lamps in the field of photochemistry have gradually increased. Ultraviolet (UV) radiation of electrodeless lamps has broad application prospects in surface modification of materials, dry etching, film deposition, synthesis of organic matter, and treatment of photooxidative pollution. Since this type of light source has no electrodes, it will not produce blackening due to electrode oxidation, loss and sealing problems like other discharge light sources, and it is rarely affected by the working voltage (no longer just 220 V, but any voltage can be used) ), operating frequency, and operating current (the waveform is not only sinusoidal, it can be rectangular wave, pulse wave), and has made great progress in many qualities such as light effect, light color, life, shape, and filling material.

Excimer is a general term for bound high-energy state (lifetime 10 ^-6 ~ 10 ^-7 s) and repulsive (weakly bound) ground state molecules (lifetime 10 ^-13 s), also known as three-body collision non-radiative recombination or atomic collision states. Excimers can only be produced under certain special gas discharge conditions, such as dielectric barrier discharge (Dielectric Barrier Discharge, DBD), high-energy electron beams, alpha particles, synchrotron radiation, high-frequency discharge, microwave discharge, pulse discharge and other conditions. During discharge, the atoms are excited to a high electronic energy level, and these excited state atoms collide with the ground state atoms or molecules to generate a molecule and transfer part of the energy through a third party to make it relax from a high vibrational excited state to a low vibrational excited state , become a relatively stable molecule, while emitting ultraviolet radiation of the corresponding wavelength.

At present, the dielectric barrier discharge electrodeless excimer ultraviolet lamp and the microwave discharge electrodeless lamp are mainly used in pollution control, and the electrodeless excimer ultraviolet lamp is applied to the degradation of pollutants, and most of them still stay in the water phase pollutants.

For example, Chinese patent document CN 2592631 Y (patent application number: ZL 02264075.4) discloses an excimer ultraviolet light source, which includes a cooling water wave tube with an electrode electrically connected to a high-frequency high-voltage power supply and a gas discharge wave tube encapsulated therein , this light source can be widely used in water circulation disinfection treatment or photochemical reaction, when filled with Xe and Cl ₂ mixed gas, it can radiate ultraviolet light with a wavelength of 308nm. Chinese patent document CN 101857283 B (patent application number: ZL 2010 10203436.2) discloses a device for treating wastewater by a microwave electrodeless excimer lamp and a gas distribution system for the lamp. The device for treating wastewater includes a microwave power supply, a microwave generator, an electrodeless excimer lamp The lamp, the waste water treatment pool, and the microwave generator include a shell, a magnetron and a resonant cavity shell. Both of the above two patents apply the non-polar excimer ultraviolet lamp to water phase pollutants.

Regarding the technical solution of applying the electrodeless excimer ultraviolet lamp to gaseous pollutants, Chinese patent document CN1319600 C (patent application number: ZL 200510030278.4) discloses a low-concentration, high-volume malodorous gas treatment device and method. The device consists of a filter, The photolysis reactor, the honeycomb activated carbon bed and the fan are connected in sequence, and the photolysis reactor adopts a 172nm excimer ultraviolet lamp, which is composed of an outer quartz sleeve, an outer electrode, an inner quartz sleeve and an inner electrode from outside to inside. The outer electrode is between the outer quartz sleeve and the inner quartz sleeve, and the inner electrode is inside the inner quartz sleeve. The gas to be degraded enters the reaction zone from the gap between the outer quartz sleeve and the reactor wall, and the airflow after the reaction in the photolysis reactor enters the honeycomb activated carbon bed to continue the reaction. The principle of the device is to place the electrodeless excimer lamp in the middle of the reactor, and the gas degrades under the light when it flows past the electrodeless lamp.

Chinese patent document CN 1216680C (patent application number: 01814678.3) discloses an excimer UV photoreaction device. Multiple excimer lamps are arranged in parallel with the irradiated body. The ultraviolet lamp irradiates ultraviolet light to the object to be irradiated, so that a photochemical reaction occurs on the surface of the object to be irradiated. The structure of the device is relatively complicated, and it occupies a large area, and there are many equipments that need to be maintained in the later operation.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for catalytically degrading waste gas by an electrodeless excimer light.

The technical solution for realizing the object of the present invention is a method for catalytically degrading waste gas by light of an electrodeless excimer lamp. The reactor used includes three layers of quartz dielectric layers, inner electrodes, outer electrodes and a high-voltage power supply.

The three-layer quartz medium layer includes a coaxial first quartz tube, a second quartz tube and a third quartz tube arranged sequentially from the inside to the outside; the inner electrode is arranged inside the first quartz tube, and the outer electrode is arranged at the second Two outer sides of the quartz tube.

Both ends of the first quartz tube are open, and the inner cavity of the first quartz tube is the reaction zone of zone III; the second quartz tube is set outside the first quartz tube, and the upper and lower ends of the second quartz tube are sintered The outer surface of a quartz tube, so that a closed annular cavity is formed between the second quartz tube and the first quartz tube, which is used as gas to fill the II region; both ends of the third quartz tube are open, and the third quartz tube and the second quartz tube The zone I reaction zone is formed between the tubes.

When photocatalytically degrading waste gas, after the gas-filled zone II is evacuated, the gas-filled zone II is filled with a rare gas or a rare gas-halogen mixture; after the high-voltage power supply is turned on, the gas in the gas-filled zone II is excited to generate excimer ultraviolet light, It radiates in the direction of the reaction area of zone I and the reaction zone of zone III.

All the exhaust gas to be degraded passes through the reaction zone of zone I and is degraded under the action of excimer ultraviolet radiation; or the exhaust gas to be degraded passes through the reaction zone of zone III and is degraded under the action of excimer ultraviolet radiation; or the exhaust gas to be degraded is diverted into The reaction zone of zone I and zone III is degraded under the action of excimer ultraviolet radiation; after the gas flows out of the reaction zone of zone I or zone III, it is drawn out by the induced draft fan and discharged.

Preferably, the waste gas to be degraded is mixed with water vapor and clean air and then enters the reactor for degradation.

Preferably, the exhaust gas to be degraded flowing out of the exhaust gas generator or the exhaust gas storage tank is initially mixed through the gas mixer, and then enters the reaction zone of zone I or zone III for degradation after passing through the multi-hole distributor of the inlet distributor.

When degrading, the rare gas filled in gas-filled zone II is Xe ₂ ; the rare gas-halogen mixed gas filled is Ar/F ₂ , Kr/Cl ₂ , Kr/Br ₂ , Kr/I ₂ , Xe/I ₂ , Xe/C ₂ , Kr/F ₂ ; the wavelength of excimer light radiated by the reactor is λ=108-345nm.

The high-voltage power supply used is an intermediate frequency pulse square wave power supply, and the discharge voltage is adjustable in the range of kV ~ kV.

The device used in the above method for catalytic degradation of exhaust gas by excimer lights includes a gas collection hood, a connecting sleeve, an air inlet distributor, a reactor, an air outlet distributor and an induced fan; the gas collection hood includes a lower gas collection hood and an upper gas collection hood , the lower gas collection hood, the connection sleeve, the reactor, the gas outlet distributor and the upper gas collection hood are arranged in sequence from bottom to top; the inlet port of the induced draft fan is connected with the gas outlet of the upper gas collection hood.

The air inlet of the lower gas collecting hood is connected with the exhaust gas generator gas outlet or the gas storage tank of the gas to be degraded, and the gas outlet of the lower gas collecting hood is connected with the inlet of the connecting sleeve through the flange; the gas outlet of the connecting sleeve is connected with the inlet The inlet ends of the gas distributor are connected.

The reactor is set between the inlet distributor and the outlet distributor; the reactor includes three layers of quartz dielectric layers, inner electrodes, outer electrodes and high-voltage power supply; the three layers of quartz dielectric layers include coaxial The first quartz tube, the second quartz tube and the third quartz tube are set; the inner electrode is set inside the first quartz tube, and the outer electrode is set on the outer surface of the second quartz tube.

Both ends of the first quartz tube are open, and the inner cavity of the first quartz tube is the reaction zone of zone III; the second quartz tube is set outside the first quartz tube, and the upper and lower ends of the second quartz tube are sintered The outer surface of a quartz tube, so that a closed annular cavity is formed between the second quartz tube and the first quartz tube, which is used as gas to fill the II region; both ends of the third quartz tube are open, and the third quartz tube and the second quartz tube The zone I reaction zone is formed between the tubes.

The air intake distributor includes a main body, a through hole, an annular groove, a through hole plug and an air intake through hole in zone I; the through hole is arranged in the center of the main body, and the annular groove is arranged on the periphery of the through hole and coaxially arranged with the through hole , the axis of the air inlet through hole in zone I is parallel to the axis of the main body and completely runs through the main body, and the outlet port of the air inlet through hole in zone I is located in the annular groove.

The through-hole plug is set in the through-hole, and the through-hole plug is a porous plug or a blind hole plug; the main body of the porous plug is a cylinder, including a blind hole and an air inlet through hole in zone III, and the blind hole is arranged on the upper part of the porous plug In the center, the air intake through hole in zone III is arranged below the blind hole and the air outlet of the air intake through hole in zone III communicates with the blind hole; the main body of the blind hole plug is a cylinder, and a blind hole is set in the center of the upper part of the blind hole plug.

The air inlet through hole in zone I of the air inlet distributor, the reaction zone in zone I and the outlet through hole in zone I of the outlet distributor are connected; when the through hole plug is a porous plug, the air inlet through hole in zone III of the air inlet distributor, The reaction zone of zone III is connected with the gas outlet hole of zone III of the gas outlet distributor.

Preferably, the device also includes a gas mixer, the gas mixer is arranged inside the connecting sleeve, the gas inlet of the gas mixer communicates with the inner cavity of the connecting sleeve, and the gas outlet of the gas mixer communicates with the inlet of the inlet distributor. The gas ends are connected.

Further, the air intake distributor also includes a porous sieve plate, which is arranged above the air intake passage holes in zone I.

Further, the air intake distributor also includes a piston channel, which is arranged in the main body along the radial direction of the main body, and each air intake through hole in zone I is correspondingly provided with a piston channel, and the piston channel communicates with the air intake through hole in zone I ; There is a piston in the piston channel, and when the piston moves from outside to inside and reaches the innermost side, it will block the air intake through hole in zone I.

The inner electrode of the reactor is a metal sheet, and the outer electrode is a metal mesh; or the inner electrode of the reactor is a metal mesh, and the outer electrode is a metal sheet; or the inner electrode of the reactor is a metal mesh, and the outer electrode is a metal mesh.

The present invention has positive effect:

(1) The electrodeless excimer lamp of the present invention uses dielectric barrier discharge to stimulate light emission, and uses a high-voltage power supply with adjustable discharge voltage and input power to excite low-pressure mixed gas (rare gas, rare gas-halogen) discharge between double-layer media to generate Excimer UV radiation. When performing waste gas degradation, firstly vacuumize the area II, then fill it with a certain pressure of gas (rare gas, rare gas-halogen), turn on the high-voltage power supply, and the mixed gas in area II is excited to generate excimer ultraviolet light to area I and The direction of the reaction zone in zone III radiates to degrade the exhaust gas.

By changing the gas filled in zone II, different wavelengths of ultraviolet light (vacuum ultraviolet VUV and UV) can be obtained, and different gases can be degraded in a targeted manner, with high energy utilization rate and good waste gas treatment effect; and the excimer lamp has a wide wavelength range ( λ=108-345nm), it has a wide range of applications and can be used for the treatment of various waste gases. In addition, the luminous intensity and luminous efficiency of the excimer lamp can be changed by changing the proportion and total pressure of the filling gas in zone II, so the proportion and total pressure of the gas can be adjusted according to the specific conditions of the exhaust gas.

(2) The device of the present invention has a simple and compact structure and a small floor space; and since there is no electrode in the excimer lamp tube used, the problem of electrode aging caused by the contact between the gas in the lamp and the metal electrode can be avoided, and the replacement and maintenance times of the lamp tube Less, long life; in addition, the excimer lamp is easy to manufacture, and the shape and size of the lamp are arbitrary.

(3) The electrodeless excimer lamp of the device of the present invention has three structural types, namely outer electrode metal mesh-inner electrode metal sheet, outer electrode metal sheet-internal electrode metal mesh and outer electrode metal mesh-inner electrode metal mesh, respectively Corresponding to outer zone degradation, inner zone degradation and inner and outer zone degradation forms. The above three structural types require different gas intake methods, which are realized by gas distributors. When using the outer zone, i.e. Zone I, for degradation, the gas distributor adopts the structure shown in Figure 6, the inner electrode is made of metal sheet, and the outer electrode is made of metal mesh; the piston is opened, and all exhaust gas enters Zone I through the gas distributor for ultraviolet radiation degradation. ; When the inner area is used for degradation, the gas distributor adopts the structure shown in Figure 7, the inner electrode adopts metal mesh, and the outer electrode adopts metal sheet; the piston is closed, and the exhaust gas enters the III area through the porous plug of the gas distributor. Degraded by UV radiation. When simultaneously degrading in Zones I and III, the gas distributor adopts the structure shown in Figure 1, and the inner and outer electrodes are made of metal mesh; the piston is opened, and the exhaust gas enters Zones I and III through the gas distributor for ultraviolet radiation degradation.

(4) In order to improve the degradation effect of exhaust gas, on the basis of excimer light photolysis, the present invention also improves in two ways: one is to add catalyst in the reaction zone to form a photocatalytic degradation system, and excimer ultraviolet light and catalyst combine photocatalysis Degradation waste gas; the second is to open a bypass on the side of the connection sleeve, and add water vapor and clean air to the connection sleeve. The waste gas to be degraded is diluted and mixed to form waste gas with a certain volume fraction of water vapor, which passes through the gas mixer and gas distributor. After mixing, they enter the reactor together for photolysis; the external gas decomposes under the action of ultraviolet light to generate O and OH free radicals, and O and OH free radicals collide with and react with the exhaust gas molecules to be degraded, increasing the concentration of target molecules. Dissociation rate, thereby improving the photolysis effect.

(5) When the present invention treats exhaust gas, after the gas from the exhaust gas generator is collected by the lower gas collecting hood, it is mixed in two stages by the gas mixer and the air inlet distributor to realize the stable and uniform air intake with split flow or non-split flow, so as to ensure stable treatment effect .

Description of drawings

Fig. 1 is the structural representation of the device of the non-polar excimer light catalytic degradation waste gas of the present invention;

Fig. 2 is the schematic diagram of the gas mixer in Fig. 1;

Fig. 3 is A-A sectional view of Fig. 2;

Fig. 4 is the schematic diagram of the gas distributor in Fig. 1;

Fig. 5 is the schematic diagram of the perforated sieve plate in Fig. 1;

Fig. 6 is the working principle diagram when the device of the present invention only has the gas to be degraded in the zone I reaction zone;

Fig. 7 is the working principle diagram when the device of the present invention only has the reaction zone of the III zone passing the gas to be degraded;

Fig. 8 is a schematic diagram of the gas distributor in Fig. 6;

Fig. 9 is the schematic diagram that catalyst is set in the reaction zone of the device shown in Fig. 1;

The markings in the above drawings are as follows:

Gas collecting hood 1, lower gas collecting hood 11, upper gas collecting hood 12;

Connecting sleeve 2, first cylindrical body 21, flange 21-1, second cylindrical body 22, air inlet 22-1, third cylindrical body 23, pressure ring 24;

Gas mixer 3, mixing part 31, tank 31-1, installation part 32;

Air intake distributor 4, main body 41, through hole 42, upper hole section 42-1, lower hole section 42-2, mounting table 42-3, annular groove 43, annular boss 44, air intake through hole 45 in zone I, Piston channel 46, piston 46-1, porous plug 47, blind hole 47-1, zone III air intake through hole 47-2, blind hole plug 48, blind hole 48-1, porous sieve plate 49, vent hole 49-1 ;

Reactor 5, first quartz tube 51, second quartz tube 52, third quartz tube 53, gas filling area 54, support frame 55;

Air outlet distributor 6, main body 61, air outlet hole 62 in area I, air outlet hole 63 in area III;

Internal electrode 71, external electrode 72, high voltage power supply 73.

detailed description

(Example 1, a device for catalytically degrading waste gas with non-polar excimer lights)

Referring to Fig. 1 , the device for catalytic degradation of waste gas by electroless excimer light in this embodiment includes a gas collecting hood 1, a connecting sleeve 2, a gas mixer 3, an inlet distributor 4, a reactor 5, an outlet distributor 6 and an induced draft fan. The air collecting hood 1 includes a lower air collecting hood 11 and an upper air collecting hood 12 . The lower gas collecting hood 11, the gas mixer 3, the reactor 5, the gas outlet distributor 6 and the upper gas collecting hood 12 are arranged sequentially from bottom to top.

The air inlet of the lower gas collecting hood 11 is connected with the exhaust gas generator gas outlet or the gas storage tank of the gas to be degraded, and the gas outlet of the lower gas collecting hood 11 is connected with the air inlet of the connecting sleeve 2 through a flange. The gas mixer 3 is arranged inside the connecting sleeve 2 , the air inlet of the gas mixer 3 communicates with the inner cavity of the connecting sleeve 2 , and the gas outlet of the gas mixer 3 communicates with the inlet end of the air inlet distributor 4 .

The connecting sleeve 2 includes a first cylindrical body 21, a second cylindrical body 22 and a third cylindrical body 23 coaxial from top to bottom, the first cylindrical body 21, the second cylindrical body 22 and the third cylindrical body The outer diameters of the three cylinders 23 become smaller in turn. A flange 21 - 1 is provided on the outer periphery of the first cylindrical body 21 , and the upper surface of the flange 21 - 1 is on the same plane as the upper surface of the first cylindrical body 21 . A circle of annular recesses is arranged downwards from the upper surface of the first cylindrical body 21 . The first cylindrical body 21 and the second cylindrical body 22 are connected by an annular connecting plate, and a mounting platform is formed between the first cylindrical body 21 and the second cylindrical body 22 . The lower side of the second cylindrical body 22 is provided with an air inlet 22-1, and the air inlet 22-1 is connected with the air inlet pipe, and the air inlet pipe is provided with a valve. The second cylindrical body 22 is connected to the third cylindrical body 23 through an annular connecting plate.

Referring to FIG. 2 and FIG. 3 , the gas mixer 3 includes a mixing part 31 and a mounting part 32 . The mixing part 31 is a cylinder with a closed lower end, and a groove 31-1 is formed on the cylindrical side of the mixing part 31. The groove 31-1 forms an oblique angle of 45 ^° with the axis of the mixing part 31, and the gas flows from the side of the mixing part 31. After entering, mix thoroughly while rotating and rising.

The gas mixer 3 is disposed on the installation platform formed between the first cylinder 21 and the second cylinder 22 of the connection sleeve 2 through the installation part 32 .

A pressure ring 24 is provided between the upper surface of the gas mixer 3 and the lower surface of the intake distributor 4 . The pressure ring 24 is cylindrical, and the lower end surface of the pressure ring 24 is in contact with the upper surface of the mounting part 32 of the gas mixer 3 , and the upper end surface of the pressure ring 24 is in contact with the lower surface of the intake distributor 4 .

Referring to FIG. 4 , the air intake distributor 4 includes a main body 41 , a through hole 42 , an annular groove 43 , an air intake through hole 45 in zone I, a piston channel 46 , a through hole plug and a porous sieve plate 49 .

The main body 41 is cylindrical, and the center of the main body 41 is provided with a through hole 42 ; the through hole 42 is coaxial with the main body 41 . Through hole 42 is made up of upper hole section 42-1 and lower hole section 42-2, and the aperture of upper hole section 42-1 is greater than the aperture of lower hole section 42-2, thereby upper hole section 42-1 and lower hole section 42-2 2 to form a mounting table 42-3.

An annular groove 43 is formed downward from the upper surface of the main body 41 , and the annular groove 43 is disposed on the outer periphery of the through hole 42 and is coaxially disposed with the through hole 42 . The bottom of the annular groove 43 is provided with an annular boss 44 , and the outer surface of the annular boss 44 is attached to the inner wall of the annular groove 43 . The annular boss 44 becomes a mounting platform in the annular groove 43 .

The air inlet through hole 45 in zone I is disposed on the outer periphery of the through hole 42 and inside the annular boss 44 in the annular groove 43 . The axis of the air inlet hole 45 in zone I is parallel to the axis of the main body 41 and completely penetrates the main body 41 ; the air outlet port of the air inlet hole 45 in zone I is located in the annular groove 43 .

Piston passages 46 are arranged in the main body 41 along the radial direction, and one piston passage 46 is correspondingly provided for each zone I air inlet through hole 45 , and the piston passage 46 communicates with the I zone air intake through hole 45 . A piston 46-1 is provided in the piston channel 46; when the piston 46-1 moves from the outside to the inside and reaches the innermost side, the piston 46-1 blocks the air intake through hole 45 in the zone I; and when the piston 46-1 moves outwards , the air intake through hole 45 in the I zone is unblocked.

A perforated sieve plate 49 is arranged above the air inlet through hole 45 in zone I. As shown in FIG. 5 , the perforated sieve plate 49 is annular, and a circle of ventilation holes 49 - 1 is provided along the circumferential direction of the perforated sieve plate 49 . The perforated sieve plate 49 is fixedly arranged above the annular boss 44 in the annular groove 43 . The exhaust gas flowing in from the air inlet through hole 45 of zone I passes through the vent hole 49-1 of the perforated sieve plate 49 and then flows into the reaction zone of zone I. The exhaust gas is further mixed as it passes through the perforated sieve plate 49 .

The through-hole plugs include porous plugs 47 and blind hole plugs 48 . The through hole plug is placed in the through hole 42 above the mount 42 - 3 . The through hole plug tightly fits the upper hole section 42 - 1 of the through hole 42 .

Still referring to Fig. 4, the main body of the porous plug 47 is a cylinder, including a blind hole 47-1 and an air inlet through hole 47-2 in zone III. A blind hole 47 - 1 is provided in the upper center of the porous plug 47 . The air intake through hole 47-2 in the III area is arranged below the blind hole 47-1 and the axis of the air intake through hole 47-2 in the III area is parallel to the axis of the blind hole 47-1, and the outlet of the air intake through hole 47-2 in the III area The air port communicates with the blind hole 47-1.

As shown in FIG. 8 , the main body of the blind hole plug 48 is a cylinder, and a blind hole 48 - 1 is provided in the center of the upper part of the blind hole plug 48 .

The reactor 5 is arranged between the inlet distributor 4 and the outlet distributor 6 .

Referring to FIG. 1 , the air outlet distributor 6 includes a main body 61 , a blind hole, an annular groove, an air outlet hole 62 in zone I and an air outlet hole 63 in zone III.

The main body 61 is cylindrical, and a blind hole is arranged upward from the lower bottom of the main body 61 , and the blind hole is coaxial with the main body 61 . The blind hole of the main body 61 of the air outlet distributor 6 has the same diameter as the blind hole 47 - 1 of the porous plug 47 . The air outlet hole 63 in zone III is disposed above the blind hole of the main body 61 , and the axis of the air outlet hole 63 in zone III is parallel to the axis of the blind hole. The air inlet of the air outlet hole 63 in zone III communicates with the blind hole of the main body 61 .

An annular groove is provided upward from the lower bottom of the main body 61 , and the annular groove is located on the outer periphery of the blind hole and is coaxial with the blind hole. The air outlet hole 62 in zone I is disposed above the annular groove of the main body 61 , and the axis of the air outlet hole 62 in zone I is parallel to the axis of the annular groove. The air inlet of the air outlet hole 62 in zone I communicates with the annular groove of the main body 61 .

The upper air collecting hood 12 is installed and fixed above the air outlet distributor 6 , and the air inlet of the upper air collecting hood 12 communicates with all the air outlets of the air outlet distributor 6 . The inlet port of the induced draft fan (not shown in the figure) communicates with the air outlet of the upper air collecting hood 12 .

The reactor 5 is arranged between the inlet distributor 4 and the outlet distributor 6 , and the reactor 5 is arranged above the perforated sieve plate 49 of the inlet distributor 4 .

The reactor 5 includes three quartz dielectric layers, an inner electrode 71 , an outer electrode 72 and a high voltage power supply 73 .

The three-layer quartz medium layer includes a first quartz tube 51 , a second quartz tube 52 and a third quartz tube 53 which are coaxial and arranged in sequence from inside to outside. The transmittance of ultraviolet light (near 200nm) of the first quartz tube 51 and the second quartz tube 52 is more than 85%; the third quartz tube 53 adopts a domestic quartz tube, and the transmittance of ultraviolet light (near 200nm) is <40 %, the wall thickness of the third quartz tube 53 is 1-2 mm.

The two ends of the first quartz tube 51 are open, and the lower end of the first quartz tube 51 is sleeved in the upper blind hole of the through hole plug of the air inlet distributor 4, and the upper end of the first quartz tube 51 is sleeved in the blind hole of the air outlet distributor 6. In the hole, the inner cavity of the first quartz tube 51 is used as a zone III reaction zone. A supporting frame 55 is set in the reaction zone of zone III as required (see Fig. 9 ).

The second quartz tube 52 is sleeved outside the first quartz tube 51, and the upper and lower ends of the second quartz tube 52 are sintered on the outer surface of the first quartz tube 51, so that the connection between the second quartz tube 52 and the first quartz tube 51 A closed annular cavity, that is, a gas-filled area 54 is formed between them, and the airtight annular cavity is used as the gas-filled area II.

Both ends of the third quartz tube 53 are open, and the lower end of the third quartz tube 53 is sleeved in the annular groove 43 of the air inlet distributor 4 and supported by the annular boss 44 in the annular groove 43 . The upper end of the third quartz tube 53 is sleeved in the annular groove of the gas outlet distributor 6 , and the outer surface of the third quartz tube 53 is in contact with the outer groove wall of the annular groove of the gas outlet distributor 6 . A zone I reaction zone is formed between the third quartz tube 53 and the second quartz tube 52 . A supporting frame 55 is set in the reaction zone of zone I as required (see Fig. 9 ).

The inlet distributor 4, the three quartz medium layers of the reactor 5 and the outlet distributor 6 are coaxially arranged.

The inner electrode 71 is arranged inside the first quartz tube 51, and the inner electrode 71 is a metal mesh or a metal sheet. When the inner electrode 71 is a metal mesh, the metal mesh is arranged close to the inner wall of the first quartz tube 51; when the inner electrode 71 is When using a metal sheet, the inner wall of the first quartz tube 51 is closely attached to a layer of rolled metal sheet as the internal electrode 71 .

The external electrode 72 is arranged on the outer side of the second quartz tube 52 . The outer surface of the second quartz tube 52 is wound with sheet metal as the external electrode 72 , or the outer surface of the second quartz tube 52 is wrapped with a metal mesh as the external electrode 72 . The outer electrode 72 is coaxially arranged with the inner electrode 71, so that the discharge is more uniform.

The outer electrode 72 and the inner electrode 71 are in communication with a high voltage power supply 73 . The high voltage power supply 73 is an intermediate frequency pulsed square wave power supply, and the discharge voltage is adjustable within the range of 0-15kV. Excited by the high-voltage power supply 73, the excimer ultraviolet radiation radiates to the reaction zone I and III, and the waste gas or air flowing through the reaction zone I and III dissociates under the action of the excimer ultraviolet radiation.

When the device adopts the blind hole plug 48, the waste gas to be treated can enter the reaction zone of zone I for degradation. At this time, it is preferable that the inner electrode 71 is made of a metal sheet, and the outer electrode 72 is made of a metal mesh, and all the excited excimer light is used to radiate to the reaction zone of the I zone, so as to improve energy efficiency.

When the device adopts the porous plug 47, the waste gas to be treated can only enter the reaction zone of zone III for degradation, or can be split into the reaction zones of zone I and zone III for degradation. When the exhaust gas only enters the reaction zone of zone III for degradation, it is preferable to use metal mesh for the inner electrode and metal sheet for the outer electrode, and all the excited excimer light is used to radiate to the reaction zone of zone III to improve energy efficiency. When the waste gas is divided into the reaction zone of zone I and zone III for degradation, the internal and external electrodes are all made of metal mesh.

In this embodiment, in order to make the structure of the device simple, the gas mixer 3 may not be provided, and the air inlet of the air inlet distributor 4 is directly connected with the air outlet of the connection sleeve 2 . However, the exhaust gas to be treated is mixed in two stages through the gas mixer + gas distributor, which can achieve uniform air intake and ensure a more stable treatment effect.

When using the device for the catalytic degradation of waste gas by lightless excimer lights, firstly vacuumize the gas-filled zone II between the first quartz tube 51 and the second quartz tube 52, and then fill it with a certain pressure of rare gas selected according to the gas to be degraded (Xe ₂ ), rare gas-halogen (Ar/F ₂ , Kr/Cl ₂ , Kr/Br ₂ , Kr/I ₂ , Xe/I ₂ , Xe/C ₂ , Kr/F ₂ ) mixed gas.

In addition, by changing the proportion and total pressure of the filling gas in the gas filling zone II, the energy distribution of the high-voltage power supply 73 for exciting excimer radiation can be changed, and the waste gas degradation effect and energy efficiency can be improved to the greatest extent.

Turn on the induced draft fan, the induced draft fan will draw the waste gas to be degraded into the reactor 5, and the waste gas to be degraded will be mixed by the gas mixer 3 and then pass through the intake distributor 4, and then flow into the reaction zone of zone I and zone III of the reactor 5 , or only enter the reaction zone of zone I, or only enter the reaction zone of zone III, after the reaction in the reactor 5, the gas is mixed again in the upper gas collecting hood 12, and then drawn out by the induced draft fan for discharge.

(Example 2, a method for catalytically degrading exhaust gas by non-polar excimer lights)

The method for catalytically degrading waste gas by light-emitting excimer light in this embodiment adopts the device described in Embodiment 1, and the through-hole plug used in the air inlet distributor 4 is a blind hole plug 48 . The inner electrode 71 is made of metal sheet, and the outer electrode 72 is made of metal mesh.

The process of photocatalytic degradation of waste gas by non-polar excimer lights is as follows: the waste gas from the waste gas generator or the waste gas storage tank is initially mixed by the gas mixer 3, and then further mixed evenly by the air inlet distributor 4, and then enters the reactor under the action of the induced draft fan 5 for purification. The outlet of the reactor 5 is 1m away from the reactor, and a sampling port is set, and the concentration of the reacted gas is detected by an online gas analyzer, and the gas degraded to the standard is discharged through the exhaust pipe.

See Figure 6. In this example, the degradation flow dynamics simulates dimethylamine waste gas, and the initial concentration is 3745 mg/m ³ . The method for degrading waste gas specifically includes the following steps:

① Vacuum the gas filling zone II, and then fill it with Kr : Cl ₂ =350:1, with a total pressure of 205torr.

② Turn on the high-voltage power supply 73, apply an external voltage of 7.2kV and a power of 78W, and the mixed gas filled with the gas in zone II is excited to generate excimer ultraviolet light to radiate to zone I, and the wavelength of excimer ultraviolet radiation is 222nm. Open the piston 46-1 of the air intake distributor 4 so that the air intake through hole 45 in the I zone is unimpeded.

③ Turn on the induced draft fan connected to the upper gas collecting hood 12, and the dimethylamine exhaust gas flows out from the outlet of the exhaust gas generator, and after being mixed by the gas mixer 3 and the intake distributor 4, it enters the reactor zone I for photolysis reaction. The flow rate of dimethylamine waste gas is 14.9 m ³ /h.

④ On-line gas analysis instrument detection shows that the removal efficiency of dimethylamine gas reaches 64.5% when the applied voltage is 7.2kV, and the energy rate is 461.4 g/(kW.h)).

In order to improve the photolysis efficiency, water vapor and clean air can be introduced into the air inlet 22-1 of the connecting sleeve 22, and the waste gas is diluted and mixed into waste gas containing a certain water vapor volume fraction, and then enters the reactor for photolysis, and the water Under the action of ultraviolet light, the gas is decomposed into ·O and ·OH free radicals to improve the photolysis effect.

(Example 3, a method for catalytically degrading exhaust gas by non-polar excimer lights)

The method for catalytically degrading waste gas by light-emitting excimer light in this embodiment adopts the device described in Embodiment 1, and the through-hole plug used in the air inlet distributor 4 is a porous plug 47 . The inner electrode 71 is made of metal mesh, and the outer electrode 72 is made of metal sheet.

See Figure 7. In this example, the degradation flow dynamics simulates dimethylamine waste gas, and the initial concentration is 3745 mg/m ³ . The method for degrading waste gas specifically includes the following steps:

① Vacuum the gas filling zone II, and then fill it with Kr : Cl ₂ =350:1, with a total pressure of 205torr.

② Turn on the high-voltage power supply 73, apply an external voltage of 6kV, and a power of 50W. The gas-filled mixture in zone II is excited to generate excimer ultraviolet light to radiate to the reaction zone in zone III. The wavelength of excimer ultraviolet radiation is 222nm. Closing the piston 46-1 of the intake distributor 4 makes the intake through hole 45 of the zone I closed, and the gas can only enter the reaction zone of the zone III through the porous plug 47.

③ Turn on the induced draft fan connected to the upper gas collecting hood 12, and the exhaust gas of dimethylamine flows out from the outlet of the exhaust gas generator, and after being mixed by the gas mixer 3 and the air inlet distributor 4, it enters the reaction zone of the reactor III area for photolysis reaction . The flow rate of dimethylamine waste gas is 26.3 m ³ /h.

④ On-line gas analysis instrument detection shows that the decomposition efficiency of dimethylamine gas is 48.6% when the applied voltage is 6kV.

(Example 4, method for catalytic degradation of waste gas by non-polar excimer light)

The through-hole plug used in the air inlet distributor 4 of the device used in this embodiment is a porous plug 47, and the inner electrode 71 is made of metal mesh, and the outer electrode 72 is made of metal mesh.

See Fig. 1, the rest of the method of the non-polar excimer light catalytic degradation exhaust gas of this embodiment is the same as that of embodiment 3, the difference is:

Step ① Vacuum the gas filling zone II, and then fill it with Kr:Br ₂ =350:1, with a total pressure of 150torr.

Step ② gas filling the mixed gas in zone II is excited to generate excimer ultraviolet light to radiate to the reaction zones of zone I and zone III, and the wavelength of excimer ultraviolet radiation is 207nm. Opening the piston 46-1 of the air inlet distributor 4 makes the air inlet through hole 45 in the I area unblocked, and the gas splits into the I area reactor and the III area reaction area for reaction.

Step ④ On-line gas analysis instrument detection shows that the decomposition efficiency of dimethylamine gas is 35.4% when the applied voltage is 6kV.

(Example 5, a method for catalytically degrading exhaust gas by non-polar excimer lights)

In this embodiment, the method for catalytically degrading waste gas by light-emitting excimer lights adopts the device described in Embodiment 1, and the through-hole plug used in the air inlet distributor 4 is a porous plug 47 . The inner electrode 71 is made of metal mesh, and the outer electrode 72 is made of metal mesh.

As shown in Figure 1, the degradation flow dynamics of this embodiment simulates monomethylamine exhaust gas, with an initial concentration of 2010 mg/m ³ . The method for degrading exhaust gas specifically includes the following steps:

① Vacuum the gas filling zone II, and then fill it with Kr : I ₂ =350:1, with a total pressure of 300torr.

② Turn on the high-voltage power supply 73, apply an external voltage of 7.2kV, and a power of 78W. The mixed gas filled with gas in zone II is excited to generate excimer ultraviolet light to radiate to the reaction zones in zone I and zone III. The wavelength of excimer ultraviolet radiation is 206nm. Opening the piston 46-1 of the air inlet distributor 4 makes the air inlet through hole 45 in the I area unblocked, and the gas splits into the I area reactor and the III area reaction area for reaction.

③ Turn on the induced draft fan connected to the upper gas collecting hood 12, and a methylamine exhaust gas flows out from the outlet of the exhaust gas generator, and after being mixed by the gas mixer 3 and the intake distributor 4, it enters the reaction zone of the reactor zone I and zone III to carry out photolysis reaction. The flow rate of monomethylamine waste gas is 26.3 m ³ /h.

④ On-line gas analysis instrument detection shows that the decomposition efficiency of dimethylamine gas is 89.5% when the applied voltage is 7.2kV.

(Example 6, Method for Catalytic Degradation of Exhaust Gas by Non-polar Excimer Lighting)

In this embodiment, the method for catalytically degrading waste gas by light-emitting excimer lights adopts the device described in Embodiment 1, and the through-hole plug used in the air inlet distributor 4 is a porous plug 47 . The inner electrode 71 is made of metal mesh, and the outer electrode 72 is made of metal mesh.

See Figure 1. In this example, the degradation flow dynamics simulates the waste gas of toluene, and the initial concentration is 1500 mg/m ³ . The method for degrading the waste gas specifically includes the following steps:

① Vacuum the gas filling zone II, and then fill it with Kr : I ₂ =350:1, with a total pressure of 300torr.

② Turn on the high-voltage power supply 73, apply an external voltage of 7.2kV, and a power of 78W. The mixed gas filled with gas in zone II is excited to generate excimer ultraviolet light to radiate to the reaction zones in zone I and zone III. The wavelength of excimer ultraviolet radiation is 206nm. Opening the piston 46-1 of the air inlet distributor 4 makes the air inlet through hole 45 in the I area unblocked, and the gas splits into the I area reactor and the III area reaction area for reaction.

③ Turn on the induced draft fan connected to the upper gas collecting hood 12, and the toluene exhaust gas flows out from the outlet of the exhaust gas generator, and after being mixed by the gas mixer 3 and the inlet distributor 4, it enters the reaction zone of the reactor zone I and zone III for photolysis reaction. The flow rate of toluene waste gas is 26.3 m ³ /h.

④ On-line gas analysis instrument detection shows that the decomposition efficiency of toluene gas is 70.5% when the applied voltage is 7.2kV.

(Example 7, the method for catalytic degradation of exhaust gas by non-polar excimer light)

As shown in FIG. 9 , the method for catalytically degrading waste gas by non-polar excimer light in this embodiment adopts the device described in Embodiment 1, and the through-hole plug used in the air inlet distributor 4 is a porous plug 47 . The inner electrode 71 is made of metal mesh, and the outer electrode 72 is made of metal mesh. A support frame 55 is arranged in the reaction zone of zone I and zone III, and the reaction zone of zone I and zone III is filled with catalyst TiO ₂ .

In this example, the method for catalytically degrading waste gas by non-polar excimer lamp light is the same as in Example 6. Due to the presence of the catalyst, the on-line gas analyzer test shows that the decomposition efficiency of toluene gas is 92.3 when the applied voltage is 7.2kV.

Claims (3)

1. A method for catalytically degrading waste gas by electroless excimer lights, characterized in that: the reactor (5) used includes three layers of quartz dielectric layers, inner electrodes (71), outer electrodes (72) and high-voltage power supply (73); The three-layer quartz medium layer includes a coaxial first quartz tube (51), a second quartz tube (52) and a third quartz tube (53) arranged in sequence from inside to outside; the inner electrode (71) is set on Inside the first quartz tube (51), the external electrode (72) is arranged on the outer surface of the second quartz tube (52); Both ends of the first quartz tube (51) are open, and the inner cavity of the first quartz tube (51) is the reaction zone of zone III; the second quartz tube (52) is set outside the first quartz tube (51), and the second The upper and lower ends of the quartz tube (52) are sintered on the outer surface of the first quartz tube (51), so that a closed annular cavity is formed between the second quartz tube (52) and the first quartz tube (51), Fill zone II as gas; both ends of the third quartz tube (53) are open, and zone I reaction zone is formed between the third quartz tube (53) and the second quartz tube (52); When photocatalytically degrading waste gas, after the gas-filled zone II is evacuated, the gas-filled zone II is filled with rare gas or rare gas-halogen mixed gas; after the high-voltage power supply (73) is connected, the gas in the gas-filled zone II is excited to generate quasi-halogen. Molecular ultraviolet light radiates in the direction of the reaction zone of zone I and the reaction zone of zone III; The exhaust gas to be degraded flowing out of the exhaust gas generator or the exhaust gas storage tank is mixed with water vapor and dry clean air, and is initially mixed through the gas mixer (3), and then enters zone I after passing through the porous air inlet distributor (4) Reaction zone or zone III reaction zone for degradation; all waste gas to be degraded passes through zone I reaction zone and is degraded under the action of excimer ultraviolet radiation; or all exhaust gas to be degraded passes through zone III reaction zone and is degraded under the action of excimer ultraviolet radiation be degraded; or the exhaust gas to be degraded is diverted into the reaction zone of zone I and zone III, and is degraded under the action of excimer ultraviolet radiation; after the gas flows out of the reaction zone of zone I or zone III, it is exhausted by the induced draft fan. 2. The method according to claim 1, characterized in that: the rare gas filled in the gas filling zone II is Xe; the rare gas-halogen mixed gas filled is Ar/F ₂ , Kr/Cl ₂ , Kr/Br ₂ , Kr/I ₂ , Xe/I ₂ , Xe/Cl ₂ , Kr/F ₂ ; the wavelength λ=108-345nm of the excimer light radiated by the reactor (5). 3. The method according to claim 1, wherein the method for catalytically degrading exhaust gas by excimer lights is characterized in that: the high-voltage power supply (73) is an intermediate-frequency pulsed square-wave power supply, and the discharge voltage is adjustable within the range of 0kV-15kV.