CN102745850B - Method for maintaining internal key components of microwave photocatalytic wastewater-degrading processing device - Google Patents

Abstract

The invention relates to a method for maintaining key internal components of a microwave photocatalytic wastewater degradation treatment device, and belongs to the technical field of wastewater treatment. In the existing microwave photocatalytic wastewater degradation technology, there are problems of thermal corrosion damage of the organic matter membrane separation module, and the problem of fouling on the outside of the quartz tube used for the screen protection of the electrodeless ultraviolet lamp. The present invention aims to solve the above problems in a package. The steps of the method of the present invention include enclosing the membrane separation assembly in a cage-shaped microwave shielding cover made of metal; installing an ultrasonic transducer inside or on the outer surface of the microwave photocatalytic reactor; and starting its related power supply. The microwave isolation method of the present invention does not hinder the function and operation of the membrane separation module; the method of the present invention uses high-frequency ultrasonic waves to achieve immediate removal of the fouling without dismantling the machine or stopping the machine. The method of the invention solves the immediate maintenance problem of two key components in the microwave photocatalytic device in a package.

Description

Maintenance method for internal key components of microwave photocatalytic wastewater degradation treatment device

technical field

The invention relates to a method for maintaining key internal components of a microwave photocatalytic wastewater degradation treatment device, and belongs to the technical field of CO2F wastewater treatment.

Background technique

Microwave photocatalytic degradation treatment technology, as an effective harmless treatment technology for industrial wastewater containing organic pollutants, has developed rapidly in recent years.

Regarding the microwave photocatalytic degradation technology, as an example, refer to the Chinese patent application with publication number CN102260003A.

The Chinese patent application with the publication number CN102260003A uses microwaves as the excitation source to excite the electrodeless ultraviolet lamp to emit ultraviolet rays, and irradiates the suspension mixed with photocatalyst titanium dioxide inside the liquid. The electrodeless ultraviolet lamp is shrouded and protected by a quartz tube. , an air pump continuously injects air into the inner chamber of the quartz tube, and the air overflowing from the quartz chamber communicates with the microporous aeration head at the bottom of the reactor through the pipe. The upper area is the microwave photocatalytic reaction zone. This scheme also uses the built-in membrane separation module of the reactor to extract the purified water, and uses the membrane separation module to realize the interception and reuse of the photocatalyst titanium dioxide particles; A partition is set up between the electrodeless ultraviolet light source and the membrane separation module to prevent ultraviolet rays from damaging the organic matter membrane separation module; part of the air that passes into the reactor directly participates in the photocatalytic degradation reaction relying on the photocatalyst titanium dioxide, and Part of the air, under the direct irradiation of ultraviolet light, generates a certain amount of ozone, which of course also plays a direct role in the oxidation and degradation of organic pollutants.

The Chinese patent application with the publication number CN102260003A has undoubtedly played a non-negligible role in promoting the progress of microwave photocatalytic wastewater degradation technology, and the work carried out by its researchers in this field is admirable.

The industrial wastewater subjected to microwave photocatalytic degradation treatment is inevitably mixed with some metal particles and carbon particles derived from the wear process of the mechanical system. Even if the amount is small, its existence is almost unavoidable. The organic matter membrane separation module in the patent application is installed in the microwave photocatalytic reaction area, and the partition plate for blocking ultraviolet rays installed between the quartz tube and the membrane separation module cannot block the microwave, so the microwave The actual action area must cover the installation area of the organic matter membrane separation module mentioned in the scheme. Based on the working mechanism of the membrane separation module, the deposition process of the above-mentioned metal particles and carbon particles on the surface of the organic matter of the membrane separation module It is unavoidable, and such particles such as metal particles and carbon particles are just good absorbing media for microwave energy, and particles such as metal particles and carbon particles that have absorbed microwave energy in a precipitated state will naturally The surface layer of the organic membrane separation module that is closely attached to it produces continuous penetration damage based on the thermal penetration mechanism. As mentioned above, due to the structure of the device in the CN102260003A application, only polyvinylidene fluoride membrane materials can be used. The temperature resistance of vinyl fluoride film is about 140 degrees Celsius, which is indeed much higher than that of ordinary film materials. However, the metal particles and carbon particles in the deposited state that have absorbed microwave energy have a point-shaped hole-like heat penetration. Corrosion is very easy to break through the temperature-resistant temperature limit of the polyvinylidene fluoride membrane. Due to the above reasons, it is conceivable that the actual service life of the PVDF membrane in the device of the CN102260003A application will be much lower than the expected ideal service life, the structure of the device of the CN102260003A application determines that under the framework of this structure, the above-mentioned point-like hole-through thermal penetration damage problem cannot be avoided.

On the other hand, in the device structure expressed in the Chinese patent application whose publication number is CN102260003A, the outer wall of the quartz tube used for shielding the electrodeless ultraviolet lamp refers to the outer wall of the quartz tube. When dealing with industrial wastewater, it is inevitable to gradually accumulate fouling. Of course, the fouling substances are mainly inorganic impurities that are not easily touched by photocatalytic reactions. The fouling phenomenon formed by this mechanism is easy to be observed after the equipment has been running for a long time ; the fouling layer attached to the outer wall of the quartz tube, though only a thin layer, is enough to cause significant blocking to the ultraviolet radiation of the electrodeless ultraviolet lamp, which will lead to the actual treatment effectiveness of this microwave photocatalytic reaction treatment device It is greatly reduced; during the use of the laboratory scale, the above-mentioned fouling problem is not easy to detect, but on the industrial application scale, the fouling problem will undoubtedly be highlighted; On the premise, it is another technical problem worthy of attention to immediately and effectively remove the fouling layer on the outer wall of the quartz tube and maintain the continuous high efficiency of the microwave photocatalytic treatment device.

Contents of the invention

The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned CN102260003A application, that is, the thermal corrosion damage problem of the membrane separation module caused by the structural characteristics and operating mechanism of the case, and the outer wall area of the quartz tube. Scale problem, develop a method that can solve the above problems in a package.

The present invention solves the technical problem through the following solution, which provides a method for maintaining key components inside a microwave photocatalytic wastewater degradation treatment device. The method includes the following steps: The membrane separation assembly inside the catalytic reaction chamber is packed so that the membrane separation assembly is inside the cage-shaped microwave shielding cover. The outline of the cage-shaped microwave shielding cover is box-shaped. Containing many holes, the overall position of the cage-shaped microwave shielding cover is also inside the microwave photocatalytic reaction chamber, and the cage-shaped microwave shielding cover is a component for isolating the membrane separation assembly from the microwave source; b , installing an ultrasonic transducer on the inside or outside of the microwave photocatalytic reactor; c, connecting the ultrasonic transducer to one end of the high-frequency oscillating electrical signal transmission cable; d, connecting the high-frequency oscillating electrical signal transmission cable to the The other end is connected with the high-frequency oscillating electrical signal generator; e, connect the high-frequency oscillating electrical signal generator to the power supply.

In view of the microwave environment involved in this reactor, the ultrasonic transducer structure that can resist microwave interference and damage is a preferred structure, therefore, the preferred ultrasonic transducer suitable for this case is an armored ultrasonic transducer with a metal shell . Armored ultrasonic transducers with metal shells can be customized from professional manufacturers of ultrasonic devices.

The ultrasonic transducer described in this case can be any form of ultrasonic transducer available on the market; the ultrasonic transducer described in this case can of course also be an ultrasonic transducer with an ultrasonic horn attached.

Regardless of whether the ultrasonic transducer is an armored ultrasonic transducer with a metal casing, and whether it is installed internally or externally, further shielding against microwaves is always beneficial, Based on this consideration, a microwave shield can be further coated on the periphery of the ultrasonic transducer, the microwave shield can be a cage-shaped electromagnetic isolation cover, and the cage-shaped electromagnetic isolation cover is used to prevent microwaves from affecting the ultrasonic waves. Interference and damage to the transducer, the ultrasonic transducer is covered by the cage-shaped electromagnetic isolation cover, and the material of the cage-shaped electromagnetic isolation cover is metal. The cage-shaped electromagnetic isolation cover made of metal, as the name suggests, is a porous, cage-shaped metal cover.

The box-cage microwave shielding cover and the cage-shaped electromagnetic isolation cover mentioned in this case are both metal cage components used to isolate the influence of microwaves. However, the objects to be protected are different, and the mechanisms of the damage to be resisted are different.

Because ultrasonic cavitation is a very powerful effect, low-frequency ultrasonic waves have a strong impact on the surface of the object workpiece, and the cavitation effect of the low-frequency ultrasonic waves is not suitable for the outer surface of the quartz tube inside the reactor. , because, if the ultrasonic mechanism is used for a long time to radiate low-frequency ultrasonic waves into the reactor, the strong ultrasonic cavitation effect of the low-frequency ultrasonic waves will cause the destruction of the outer surface finish of the quartz tube inside the reactor, and gradually develop to the wool sand glass The transformation of surface morphology, which also hinders the penetration of ultraviolet light to a certain extent, deviates from the original intention of this case; however, with the increase of the selected ultrasonic frequency, the damage of cavitation to the target workpiece gradually weakens until it can be ignored ; therefore, the preferred ultrasonic frequency suitable for this case is not an arbitrary frequency.

As mentioned above, in order to avoid the wool sanding damage of the outer surface of the quartz tube inside the reactor due to ultrasonic cavitation, the preferred frequency of the ultrasonic waves emitted by the ultrasonic transducer should be at least above 100KHz; The preferred frequency range of the emitted ultrasonic waves is between 100 KHz and 12 MHz.

At the same time, in order to avoid damage to the membrane separation components inside the reactor by ultrasonic waves, it is advisable to use low-power ultrasonic waves; the choice of ultrasonic power depends on the volume of the reactor, the capacity of the internal liquid, the number of ultraviolet lamps, the number of quartz tubes, etc. It also depends on the choice of the mode of ultrasonic emission, namely continuous or intermittent, etc., and the ultrasonic power can be determined comprehensively according to the needs of the actual reactor system.

The power supply connected with the high-frequency oscillating electric signal transmission cable can be a power supply that is simply connected to use, and the power supply can certainly be a power supply with a power timing switch; using this power supply with a power timing switch, you can Realize the timing emission control of ultrasonic waves; the timing switch of the power supply can of course be a timing switch with a program module. Described various time switches all have commercially available.

In view of the use environment of the ultrasonic transducer in this case, the problem of corrosion resistance is worth noting. Therefore, the preferred solution of the ultrasonic transducer is to use an ultrasonic transducer with a polytetrafluoroethylene protective layer or a polyvinylidene fluoride protective layer. Therefore, the steps of the method of this case may also include coating and covering the surface of the ultrasonic transducer with a polytetrafluoroethylene protective layer or a polyvinylidene fluoride protective layer.

Only the polytetrafluoroethylene coating and polyvinylidene fluoride coating technology itself is known to professionals in the field of polymer material coating technology.

Ultrasonic transducers with polytetrafluoroethylene protective layer or polyvinylidene fluoride protective layer can also be customized directly from professional manufacturers of ultrasonic devices.

The method of this case may further include some other steps, such as: coating and covering the polytetrafluoroethylene protective layer or polyvinylidene fluoride protective layer on the high-frequency electrical signal transmission cable; the other steps are also such as: The wire mesh shielding layer is installed on the high-frequency electrical signal transmission cable, and the wire mesh shielding layer is used to block the microwave radiation interference of the cable and its surrounding environment; and so on.

The quantity of described ultrasonic transducer also can be more than one; The quantity of described ultrasonic transducer is not limited, and the quantity of described ultrasonic transducer can be arbitrary quantity; The quantity of described ultrasonic transducer can be according to The needs of the actual system are comprehensively considered and set.

The advantage of the present invention is that the membrane separation assembly is enclosed in a cage-shaped microwave shield made of metal, so that the influence of microwave radiation cannot reach the structural position of the membrane separation assembly, thereby preventing the membrane separation assembly from attaching to the surface of its elements. Substances such as metal particles and carbon particles absorb microwave energy, thereby restraining the process of thermal corrosion damage of the membrane separation module.

On the other hand, in the method of this case, by installing an ultrasonic transducer inside or on the outer surface of the reactor, using high-frequency ultrasonic waves, the quartz crystal inside the microwave photocatalytic reactor can be realized without stopping the machine or disassembling the machine. The immediate removal of fouling on the outer surface of the tube maintains the high permeability of the quartz tube to ultraviolet light and maintains the continuous high efficiency of the microwave photocatalytic reaction device.

The method of this case solves the maintenance problems related to the two key components in a package.

Detailed ways

The implementation of the method in this case, the main steps are as follows:

a, The membrane separation module located inside the microwave photocatalytic reaction chamber is covered with a metal cage-shaped microwave shield, so that the membrane separation module is inside the cage-shaped microwave shield, and the outline of the cage-shaped microwave shield is Box-shaped, the box-shaped microwave shielding cover with a box-shaped outline contains many holes, and the overall position of the cage-shaped microwave shielding cover is also inside the microwave photocatalytic reaction chamber. The cage-shaped microwave shielding cover is used Components used to isolate the membrane separation module from the microwave source;

b, installing ultrasonic transducers on the inside or outside of the microwave photocatalytic reactor;

c, connecting the ultrasonic transducer to one end of the high-frequency oscillating electrical signal transmission cable;

d, connecting the other end of the high-frequency oscillating electrical signal transmission cable to the high-frequency oscillating electrical signal generator;

e. Connect the high-frequency oscillating electrical signal generator to the power supply.

The ultrasonic transducer is preferably a sheathed ultrasonic transducer with a metal housing.

The ultrasonic transducer preferably has an ultrasonic transducer with a cage-shaped electromagnetic isolation cover, and the material of the cage-shaped electromagnetic isolation cover is metal.

The preferred transmitting frequency range of the ultrasonic transducer is between 100 KHz and 12 MHz.

The power supply is preferably a power supply with a power timing switch.

The implementation of the method also includes the following steps of coating and wrapping the polytetrafluoroethylene protective layer or the polyvinylidene fluoride protective layer on the surface of the ultrasonic transducer.

The implementation of the method also allows to further include the step of coating and coating the polytetrafluoroethylene protective layer or the polyvinylidene fluoride protective layer on the high-frequency electrical signal transmission cable.

The thickness of the coated and coated polytetrafluoroethylene protective layer or polyvinylidene fluoride protective layer can be any specified thickness; any thickness of the protective layer can play a certain protective role; the thickness of the protective layer can be determined according to the actual situation. Need to be sure.

The implementation of the method also allows to further include the following steps, the wire mesh shielding layer is installed on the high-frequency electrical signal transmission cable, and the wire mesh shielding layer is used to block the microwave radiation interference of the cable and its surrounding environment.

The ultrasonic transducer, together with the high-frequency oscillating electrical signal generator connected to it via the high-frequency oscillating electrical signal transmission cable, and the relevant power supply constitute an ultrasonic emission mechanism. In the case of continuous operation of the ultrasonic emission mechanism, The progress of fouling on the outer side of the quartz tube can be completely suppressed.

Of course, the continuous operation is not necessary, because it can also be operated intermittently, or manually start its operation according to specific needs without dismantling the machine for cleaning, such as manually starting the operation for several minutes or tens of minutes at intervals of several weeks; etc. wait.

Both the box-cage microwave shielding cover and the cage-shaped electromagnetic isolation cover involved in the implementation of this case are metal cage components used to isolate the influence of microwaves, but the protection objects are different, and the damage mechanisms to be resisted are different.

The ultrasonic transducers involved in the implementation of this case can be commercially available ultrasonic transducers of any form; of course, the ultrasonic transducers involved in the implementation of this case can also be ultrasonic transducers with an ultrasonic horn attached.

Claims (5)

1. the inner key member maintaining method of microwave and photo catalysis wastewater degradation processing unit, this wastewater degradation processing unit is a microwave and photo catalysis reactor, this reactor is using microwave as excitaton source, excite electrodeless ultraviolet lamp transmitting ultraviolet ray, irradiate the suspension-turbid liquid that is mixed with photochemical catalyst titanium dioxide in liquid internal, this electrodeless ultraviolet lamp is shrouded and is protecting by quartz ampoule, there is air pump to continue to inject air to this quartz ampoule inner chamber, the air being overflowed by quartz cavity is via pipeline and the micro porous aeration head UNICOM that is positioned at reactor bottom, the lower zone of this inside reactor is aeration zone, the upper area of this inside reactor is microwave and photo catalysis reaction zone, this reactor is also with built-in membrane separation assemblies, carry the water of analysing after purification, and realize holding back again of photochemical catalyst titanium dioxide fine particles with this membrane separation assemblies and use, among the structure of this reactor, between its non-polar ultraviolet light source and membrane separation assemblies, set up dividing plate, this dividing plate is for preventing the radiation damage of ultraviolet ray to organic membrane separation assemblies, it is characterized in that, the key step of the method is as follows: a, the membrane separation assemblies that is positioned at microwave and photo catalysis inside reactor is contained with the boxes and baskets shape micro-wave screening cover of metal material, make the inside of membrane separation assemblies in this boxes and baskets shape micro-wave screening cover, this its appearance profile of boxes and baskets shape micro-wave screening cover is box-shaped, this profile is on the boxes and baskets shape micro-wave screening cover of box-shaped and contains many holes, this its overall position of boxes and baskets shape micro-wave screening cover is also the inside at described microwave and photo catalysis reactor, this boxes and baskets shape micro-wave screening cover is the member for membrane separation assemblies and microwave source are kept apart, b, installs ultrasonic transducer at inside or the outer surface of microwave and photo catalysis reactor, and its frequency of the ultrasonic wave that this ultrasonic transducer is launched is between 100KHz and 12MHz, c, is connected this ultrasonic transducer with one end of higher-order of oscillation electric signal transmission cable, d, is connected the other end of this higher-order of oscillation electric signal transmission cable with higher-order of oscillation electric signal generator, e, switches on power higher-order of oscillation electric signal generator.

2. the inner key member maintaining method of microwave and photo catalysis wastewater degradation processing unit according to claim 1, is characterized in that, this ultrasonic transducer is the ultrasonic transducer with the armouring of metal shell.

3. the inner key member maintaining method of microwave and photo catalysis wastewater degradation processing unit according to claim 1 and 2, it is characterized in that, this ultrasonic transducer is coated wherein by cage shape electromagnetic isolation cover, the material of this cage shape electromagnetic isolation cover is metal material, and this cage shape electromagnetic isolation cover is for stoping the interference of microwave to ultrasonic transducer.

4. the inner key member maintaining method of microwave and photo catalysis wastewater degradation processing unit according to claim 1, is characterized in that, this power supply is the power supply with electric power timing switch.

5. the inner key member maintaining method of microwave and photo catalysis wastewater degradation processing unit according to claim 1; it is characterized in that; the method is further comprising the steps of, at the external coating of ultrasonic transducer, coated polytetrafluoroethylene protective layer or Kynoar protective layer.