A cleaning and regenerating device for denitration catalytic filter bags and a working method thereof

Abstract

The present application relates to flue gas denitration technical field, specifically to a kind of denitration catalytic filter bag's cleaning regeneration device and working method, the device includes water tank, liquid preparation tank, filter, delivery pump, ultrasonic cleaner, waste liquid pump, clarifier and liquid return pump connected in sequence by pipeline, the outlet of liquid return pump is connected with the recovery liquid inlet of liquid preparation tank, the liquid outlet of liquid preparation tank is connected with the liquid outlet inlet of clarifier, liquid preparation tank outlet valve and liquid supplement valve are arranged in sequence on the pipeline between delivery pump and the bottom inlet of ultrasonic cleaner, the top outlet of ultrasonic cleaner is connected with the inlet of external electric heater, the pipeline between liquid preparation tank outlet valve and liquid supplement valve respectively, the outlet of external electric heater is connected with circulating pump, the outlet of circulating pump is connected with output valve, the outlet of output valve is connected with the bottom inlet of ultrasonic cleaner.The denitration catalytic filter bag's cleaning regeneration device of the present application can realize catalytic filter bag recycling, prolong the service life of catalytic filter bag, reduce the operation cost of flue gas purification.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flue gas denitration technology, in particular to a cleaning and regenerating device for denitration catalytic filter bag and a working method thereof. BACKGROUND

[0002] Nitrogen oxides (NOx) contained in flue gas cause great harm to the environment and human health, and have been concerned by the government, environmental protection departments and relevant technical personnel. The common technology to meet low NOx emission is selective non-catalytic reduction (SNCR) + selective catalytic reduction (SCR). Among them, the SCR denitration technology needs to build a large SCR reaction tower, especially for low-temperature SCR denitration. In order to avoid the poisoning and deactivation of the denitration catalyst, the SCR reaction tower is often arranged after the flue gas is deacidified and dedusted; and the temperature of the flue gas after deacidification and dedusting is relatively low, which cannot well meet the requirement of the reaction temperature of catalytic denitration; in order to ensure the appropriate denitration reaction temperature, a heat exchanger for adding steam to heat the flue gas is often needed, which greatly increases the consumption cost of steam. Therefore, the low-temperature SCR denitration process has problems of long process flow, complex system, large equipment, large steam consumption, large power consumption of fan, etc.

[0003] With the requirements of more stringent NOx emission and energy saving and consumption reduction, catalytic filter bag denitration as a new alternative SCR technology is more and more concerned. The catalytic filter bag denitration technology is to integrate the fiber filter bag and the denitration catalyst on the basis of the existing bag filter, so as to remove the pollutants through the integration of the fiber filter bag and the denitration catalyst, and realize the efficient purification treatment of the flue gas. The common structure of the catalytic filter bag is shown in FIG. 1, which comprises an inner bag 61, an outer bag 62 and a ring 63. The inner bag is a catalytic fiber filter material, i.e. composed of fiber filter material and SCR catalyst; the outer bag is composed of film-coated fiber filter material or film-coated catalytic fiber filter material. The flue gas first passes through the film 621, the pore size of which is much smaller than that of the ordinary fiber filter material, so as to intercept micron-sized dust and effectively realize the surface filtration of the dust, and the filtration efficiency can reach more than 99.9%. Due to the high-efficiency filtration of the film 621, the harmful dust is greatly reduced to avoid the blockage and poisoning of the catalytic fiber filter material 61. The film 621 is relatively weak, and will be worn and cracked when the air cleaning pressure is too high (≥0.8 MPa) or the installation is improper. The ring 63 is provided at the top opening of the bag mouth, and is a spring steel ring for sealing and fixing between the filter bag and the flower plate 64 of the dust collector. Figure 1

[0004] ​The catalytic filter bag as a new type of flue gas purification technology has the following advantages: (1) simultaneously achieving the removal of particulate matter and harmful gas NOx, and no secondary pollutants are produced; (2) shortening the flue gas purification process, reducing investment and operating costs; (3) long service life of the catalytic filter bag, the outer layer of the catalytic filter bag is a film structure, the inner layer is a fiber carrier structure and loaded with a catalyst, most of the dust is blocked by the film, reducing the risk of poisoning and deactivation of the inner layer catalyst, and the service life can reach 3-4 years; (4) the catalytic filter bag and the conventional bag filter have basically the same structure, except that the core element filter bag is different, and the existing conventional bag filter facilities can be replaced, reducing the difficulty of transformation.

[0005] The general catalytic filter bag uses temperature between 180℃-260℃, and the fiber filter material is generally P84, PPS, PTFE, etc. high molecular organic matter. When the use temperature is higher than 260℃, high temperature will cause the degradation of the fiber filter material. However, due to the complexity of the composition of flue gas, the catalytic filter bag still has the risk of physical blockage and chemical poisoning and deactivation at 180-260℃, as follows:

[0006] (1) Physical blockage

[0007] The physical blockage of the catalytic filter bag is mainly caused by ammonium salt and fine fly ash. Ammonium salt is generated by the reaction of SO2, SO3, HCl in flue gas with the injected denitration reducing agent NH3 inside the fiber filter material to form ammonium sulfate (AS), bisulfite (ABS), and ammonium chloride. ABS is particularly sticky and can easily adhere and deposit inside the inner bag 61, covering the active sites of the catalyst and causing catalyst deactivation. Fine fly ash mainly includes CaO, ABS, SiO2, Al2O3, etc. Although most of them are blocked on the surface of the catalytic filter bag by the film 621, they can be removed by blowing ash. However, with the long-term use of the catalytic filter bag, fine particles inevitably accumulate on the fiber filter material and catalyst, adversely affecting the activity of the catalyst. The accumulation of adhered ammonium salt and fine fly ash on the surface and pore structure of the catalytic filter bag also causes excessive resistance of the catalytic filter bag, increasing the power consumption of the system.

[0008] (2) Chemical poisoning

[0009] Chemical poisoning refers to the chemical reaction between the active components of the catalyst and alkali metals, alkaline earth metals, heavy metals (As, Hg, Pb, etc.), which causes the catalyst to be poisoned and deactivated. Alkali metals and alkaline earth metals in flue gas react on the acid active sites of the catalyst to form compounds that do not have catalytic ability, thereby causing the catalyst to be deactivated. For example, arsenic (As) poisoning is mainly caused by the reaction of gaseous arsenic trioxide (As2O3) in flue gas with oxygen inside the inner bag 61 to form diarsenic pentoxide on the surface of the catalyst, causing the catalyst to be poisoned and deactivated.

[0010] In order to reduce the poisoning inactivation of the catalyst and prolong the service life, it is generally required that the filtration dust removal efficiency of the catalytic filter bag is very high (up to 99.9% or more), so that most of the harmful substances can be removed; at the same time, the catalytic filter bag is arranged in front of the dry / half-dry deacidification device, and most of the hydrogen chloride and sulfur dioxide gas (SO2, HCl) in the flue gas can be removed to 10~30mg / m 3 However, even so, with the long-term use of the catalytic filter bag and the continuous deposition and accumulation of pollutants, there are still problems of physical blockage and chemical poisoning of the catalyst, and the catalyst needs to be regenerated regularly to restore the activity of the catalyst.

[0011] The regeneration of the catalytic filter bag is a recycling technology, which can maximize the recovery of its structure and physicochemical properties, prolong the service life, reduce the frequency of replacing the filter bag, reduce the operation cost of flue gas purification, and become the best way to handle the waste catalytic filter bag. The activity of the regenerated catalytic filter bag can be restored to 70-90% of the initial performance. The regeneration of the catalytic filter bag can be divided into two types: one is to remove the catalytic filter bag from the device and transport it to the regeneration factory for cleaning and regeneration; this method has problems such as forced shutdown during disassembly, installation of standby catalytic filter bag for flue gas, long regeneration cycle, time-consuming and labor-intensive, etc. The other is on-site regeneration, which can be completed on the running site without affecting production, saving time and labor, and saving energy. The on-site regeneration of traditional SCR catalysts often uses hot regeneration to remove the ammonium salt (commonly known as ammonium bisulfate ABS) attached to the catalyst. Because the decomposition temperature of ammonium salt is above 300℃, in engineering application, hot air above 350℃ is introduced into the SCR reaction tower to decompose ammonium bisulfate into gas, so as to achieve the purpose of removing ammonium salt from the surface of the catalyst. This on-site hot regeneration method is only suitable for traditional SCR catalysts, but not for ammonium salt inactivation regeneration of catalytic filter bags, because the tolerance temperature of catalytic filter bag should be ≤260℃, and it is difficult to fully realize the pyrolysis and release of accumulated ammonium salt of catalytic filter bag.

[0012] At present, as a new type of flue gas purification technology, the regeneration technology of catalytic filter bag is still in the research and development stage, especially the on-site regeneration technology, and there is no mature catalytic filter bag regeneration process on the market, which has affected the further promotion and application of industrial application of catalytic filter bag technology. SUMMARY

[0013] In view of the above technical problems existing in the field, the purpose of the present application is to provide a cleaning and regeneration device and working method for denitration catalytic filter bag, which can realize on-site regeneration of catalytic filter bag without affecting production on the basis of fully considering the characteristics of catalyst and dust removal filter bag.

[0014] Specifically, the present application provides the following technical solutions:

[0015] The application discloses a cleaning and regenerating device for denitration catalytic filter bags, which comprises a water tank, a liquid preparation tank, a filter, a conveying pump, an ultrasonic cleaner, a waste liquid pump, a clarifier and a liquid return pump which are sequentially connected through pipelines.

[0016] The ultrasonic cleaner comprises a cleaning tank, the upper portion of the cleaning tank is provided with a support frame, and a plurality of transducers are arranged on the cleaning tank and connected with an ultrasonic generator.

[0017] The cleaning tank is a rectangular deep tank and can accommodate a plurality of catalytic filter bags, the catalytic filter bags are vertically placed in the cleaning tank with bag openings upward and bag bottoms downward, the transducers are arranged on the four side surfaces of the cleaning tank, the transducers are uniformly arranged along the length direction of the catalytic filter bags, and the distance between the transducers and the catalytic filter bags is 10-30 cm.

[0018] The transducers are arranged in a layered staggered manner, the staggered angle between the transducers of different layers is 45-60 degrees, the distance between the transducers of different layers is not completely equal, and the transducers of different layers adopt different ultrasonic frequencies.

[0019] The catalytic filter bags are provided with columnar transducers, and the columnar transducers are connected with the ultrasonic generator.

[0020] The support frame comprises an annular ring, a support flower plate and a support angle steel, the support angle steel is located at the upper portion of the inner wall of the tank body of the cleaning tank, the support flower plate is installed on the support angle steel through bolts, a plurality of support flower plate holes are arranged on the support flower plate, V-shaped grooves are arranged around the support flower plate holes, namely, the support flower plate rotating slide rails, V-shaped protrusions are arranged on the bottom surface of the annular ring, the V-shaped protrusions are connected with the support flower plate rotating slide rails in a buckling mode, and the inner hole diameter of the annular ring is matched with the ring of the catalytic filter bag.

[0021] The clarifier comprises a mixed flocculation zone, an inclined plate sedimentation zone and a multi-pipe cyclone separation zone, a sludge hopper and a sludge discharge pipe are arranged at the bottom of the mixed flocculation zone and the inclined plate sedimentation zone, a dosing port and a stirrer are arranged in the mixed flocculation zone, a baffle is arranged at the outlet of the mixed flocculation zone, a water distribution tank is arranged behind the baffle, an overflow baffle and a suspended solid discharge port are arranged at the upper portion of the water distribution tank.

[0022] The inclined plate sedimentation zone is provided with a water distribution port below the front part, a water distribution area behind the water distribution port, a plurality of inclined plates above the water distribution area, a clear water area above the inclined plates, a triangular weir above the clear water area, and a water outlet tank above the rear part of the inclined plate sedimentation zone, which is connected with a liquid distribution main pipe.

[0023] The liquid distribution main pipe is connected with a plurality of liquid distribution branch pipes, each of which is connected with a cyclone inlet of a multi-pipe cyclone separation zone, the multi-pipe cyclone separation zone is provided with a cyclone, the upper part of the multi-pipe cyclone separation zone is provided with a central overflow port, the central overflow port is connected with a converging branch pipe, the converging branch pipe is connected with a converging main pipe, the bottom of the multi-pipe cyclone separation zone is provided with a underflow port, and the underflow port is connected with a blowdown main pipe.

[0024] The working method of the cleaning and regeneration device for the denitration catalytic filter bag is as follows: softened water is stored in a water tank, the softened water in the water tank is fed into a liquid preparation tank, chemical washing agent is fed into the liquid preparation tank through a chemical washing agent feeding port at the top of the liquid preparation tank, and cleaning liquid is prepared;

[0025] A liquid level meter is arranged in the liquid preparation tank, when the liquid level is too high, the liquid preparation tank discharges liquid to a clarifier through a liquid discharge pipe, and when the liquid level is too low, the liquid preparation tank can be supplemented with water from a water tank or recovered liquid.

[0026] The cleaning liquid in the liquid preparation tank is pumped into an ultrasonic cleaner for ultrasonic cleaning, the ultrasonic cleaner circulates and heats the cleaning liquid through an external electric heater and a circulating pump, and a temperature controller and a liquid level meter are arranged to automatically control the temperature and the liquid level of the cleaning liquid, the waste liquid after ultrasonic cleaning is discharged from the bottom of the ultrasonic cleaner, pumped into the clarifier through a waste liquid pump, and separated into clean liquid and sludge through the clarifier, the clean liquid is returned to the liquid preparation tank through a liquid return pump for reuse, and the sludge is discharged from the bottom of the clarifier through a sludge discharge pipe.

[0027] Compared with the prior art, the cleaning and regeneration device for the denitration catalytic filter bag and the working method have at least the following beneficial effects:

[0028] (1) The cleaning and regeneration device for the denitration catalytic filter bag and the working method can realize the recycling of the catalytic filter bag, prolong the service life of the catalytic filter bag, and reduce the operation cost of flue gas purification.

[0029] (2) The catalytic filter bag regeneration device and the working method can complete regeneration on site without affecting production, saving time and labor, and saving energy and reducing consumption.

[0030] (3) The method of the present invention uses ultrasonic cleaning technology to efficiently and quickly remove ammonium salts and dust deposited on the catalytic filter bag. Compared with traditional chemical cleaning and mechanical cleaning, it significantly reduces the risk of damage to the catalytic filter bag, saves effort and speed, has good cleaning effect, low cost, and is easy to automate the cleaning process.

[0031] (4) The present invention fully considers the dirt properties of the catalytic filter bag, the structural characteristics of the catalytic filter bag, and the impact and wear resistance of the filter bag itself. It makes detailed designs on the ultrasonic frequency and intensity of the ultrasonic cleaner, the arrangement and selection of the transducer, the support frame, the temperature and level control of the cleaning liquid, etc., and effectively realizes the efficient cleaning and regeneration of the catalytic filter bag.

[0032] (5) The design of the clarifier of the present invention can realize the recycling of waste liquid after cleaning. It has a compact structure, small equipment size, and adopts a skid-mounted design for easy relocation and transportation, and is easy to operate.

[0033] (6) The clarifier of the present invention has high separation efficiency. It is designed with a mixing and flocculation zone to allow fine particles to coagulate and form flocs, and then enters the inclined plate sedimentation zone for effective initial sedimentation; finally, it enters the multi-tube cyclone separation zone to enhance solid-liquid separation, thereby realizing the efficient separation and removal of tiny solid particles from waste liquid.

[0034] (7) The working method of cleaning and regenerating the catalytic filter bag of the present invention uses a liquid mixing tank to prepare the corresponding chemical cleaning solution according to the pollution status and poisoning degree of the catalytic filter bag, and designs a combination of cleaning and regeneration processes (water washing, acid washing, alkaline washing and active component replenishment), as well as cleaning steps (soaking → coarse washing → fine washing → rinsing), so as to maximize the efficient cleaning and regeneration of the catalytic filter bag. Attached Figure Description

[0035] The accompanying drawings in this application are intended to supplement the textual description in the specification with graphics, and to further explain the technical solution of this application. They do not constitute an undue limitation on this application.

[0036] Figure 1 This is a schematic diagram of the structure of the catalytic filter bag opening and body.

[0037] Figure 2 This is a schematic diagram of a cleaning and regeneration device for denitrification catalytic filter bags.

[0038] Figure 3 This is a schematic diagram of an ultrasonic cleaner.

[0039] Figure 4 for Figure 3 Sectional view of “AA” in the middle.

[0040] Figure 5 for Figure 3 Sectional view of “BB” (supporting plate).

[0041] Figure 6 Schematic diagram of rotating support and columnar transducer for ultrasonic cleaner.

[0042] Figure 7 Schematic diagram of mixed flocculation zone and inclined plate sedimentation zone for clarifier.

[0043] Figure 8 Schematic diagram of multi-tube cyclone separator skid structure for clarifier.

[0044] Figure 9 Schematic diagram of Figure 8 A-A cross-sectional view.

[0045] 1 - water tank, 2 - liquid preparation tank, 21 - stirrer, 22 - liquid level meter, 23 - flow guide baffle, 3 - filter, 4 - delivery pump, 5 - ultrasonic cleaner, 6 - catalytic filter bag, 7 - waste liquid pump, 8 - clarifier, 9 - liquid return pump.

[0046] 51 - ultrasonic generator, 52 - transducer, 53 - cleaning tank, 531 - cleaning tank steel plate, 54 - support frame, 541 - annular ring, 5411 - annular ring hole, 5412 - annular ring sliding rail, 5413 - rotating handle, 542 - support flower plate, 5421 - support flower plate hole, 5422 - support flower plate rotating sliding rail, 543 - support angle steel, 55 - columnar transducer, 56 - external electric heater, 561 - liquid preparation tank outlet valve, 562 - liquid supplement valve, 563 - input valve, 564 - output valve, 565 - discharge valve, 57 - circulating pump, 58 - flow distribution pipe.

[0047] 61 - inner bag, 62 - outer bag, 621 - film, 63 - expanding ring, 64 - dust collector flower plate.

[0048] 81 - mixed flocculation zone, 811 - dosing port, 812 - stirrer, 813 - baffle, 814 - water distribution tank, 815 - overflow baffle, 816 - suspended solids discharge port, 82 - inclined plate sedimentation zone, 821 - water distribution port, 822 - water distribution zone, 823 - inclined plate, 824 - clean water zone, 825 - triangular weir, 826 - water outlet tank, 827 - sludge hopper, 828 - sludge discharge pipe, 83 - multi-tube cyclone separation zone, 831 - liquid preparation main pipe, 832 - liquid preparation branch pipe, 833 - cyclone inlet, 834 - center overflow port, 835 - convergence branch pipe, 836 - convergence main pipe, 837 - underflow port, 838 - sewage main pipe, 839 - back plate, 8310 - bottom plate, 8311 - vertical support plate one, 8312 - vertical support plate two, 8313 - horizontal support plate three, 8314 - horizontal support plate four, 8315 - support lug. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings.

[0050] In the description of the present application, it should be understood that the terms "center", "transverse", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0051] As shown in Figures 1-8 A cleaning and regenerating device for denitration catalytic filter bags, comprising a water tank 1, a liquid preparation tank 2, a filter 3, a conveying pump 4, an ultrasonic cleaner 5, a waste liquid pump 7, a clarifier 8 and a liquid return pump 9 connected in sequence through pipelines, the outlet of the liquid return pump 9 is connected with the liquid recovery inlet of the liquid preparation tank 2, the liquid discharge outlet of the liquid preparation tank 2 is connected with the liquid discharge inlet of the clarifier 8, liquid preparation tank outlet valves 561 and liquid supplement valves 562 are arranged in sequence on the pipeline between the conveying pump 4 and the bottom inlet of the ultrasonic cleaner 5, the top outlet of the ultrasonic cleaner 5 is connected with the inlet of an external electric heater 56, the pipeline between the liquid preparation tank outlet valve 561 and the liquid supplement valve 562, the outlet of the external electric heater 56 is connected with a circulating pump 57, the outlet of the circulating pump 57 is connected with an output valve 564, and the outlet of the output valve 564 is connected with the bottom inlet of the ultrasonic cleaner 5.

[0052] The ultrasonic cleaner 5 comprises a cleaning tank 53, the upper part of the cleaning tank 53 is provided with a support frame 54, and a plurality of transducers 52 are arranged on the cleaning tank 53, and the transducers 52 are connected with an ultrasonic generator 51.

[0053] The cleaning tank 53 is a rectangular deep tank and can accommodate a plurality of catalytic filter bags 6, the catalytic filter bags 6 are vertically placed in the cleaning tank 53 with the bag opening upward and the bag bottom downward, the transducers 52 are arranged on the four sides of the cleaning tank 53, the transducers 52 are uniformly arranged along the length direction of the catalytic filter bags 6, and the distance between the transducers 52 and the catalytic filter bags 6 is 10-30 cm.

[0054] The transducers 52 are arranged in layers in a staggered manner, the staggered angle between the transducers 52 in different layers is 45°-60°, the distance between the transducers 52 in different layers is not completely equal, and the transducers 52 in different layers adopt different ultrasonic frequencies.

[0055] A columnar transducer 55 is arranged in the catalytic filter bag 6, and the columnar transducer 55 is connected with the ultrasonic generator 51.

[0056] The support frame 54 comprises a ring 541, a support flower plate 542 and a support angle steel 543. The support angle steel 543 is located at the upper part of the inner wall of the tank body of the cleaning tank 53. The support flower plate 542 is installed on the support angle steel 543 by bolts. A plurality of support flower plate holes 5421 are arranged on the support flower plate 542. A V-shaped groove, i.e. a support flower plate rotating slide rail 5422, is arranged around the periphery of the support flower plate hole 5421. A V-shaped protrusion is arranged on the bottom surface of the ring 541. The V-shaped protrusion is connected with the support flower plate rotating slide rail 5422 in a buckling manner. The inner hole diameter of the ring 541 matches the ring 63 of the catalytic filter bag 6. A rotating handle 5413 is arranged on the ring 541. When the catalytic filter bag rotates, the rotating handle is manually or automatically rotated to generate a torque, so as to realize the rotation of the catalytic filter bag.

[0057] The clarifier 8 comprises a mixed flocculation zone 81, an inclined plate sedimentation zone 82 and a multi-tube cyclone separation zone 83. The bottom of the mixed flocculation zone 81 and the inclined plate sedimentation zone 82 is provided with a sludge tank 827 and a sludge discharge pipe 828. The mixed flocculation zone 81 is provided with a dosing port 811 and a stirrer 812. The outlet of the mixed flocculation zone 81 is provided with a baffle 813. The rear of the baffle 813 is a water distribution tank 814. The upper part of the water distribution tank 814 is provided with an overflow baffle 815 and a suspended solid discharge port 816.

[0058] The front part of the inclined plate sedimentation zone 82 is provided with a water distribution port 821. The rear of the water distribution port 821 is a water distribution zone 822. The upper part of the water distribution zone 822 is provided with a plurality of inclined plates 823. The upper part of the inclined plate 823 is a clear water zone 824. The upper part of the clear water zone 824 is provided with a triangular weir 825. The rear upper part of the inclined plate sedimentation zone 82 is provided with a water outlet tank 826. The water outlet tank 826 is connected with a liquid distribution main pipe 831.

[0059] The liquid distribution main pipe 831 is connected with a plurality of liquid distribution branch pipes 832. Each liquid distribution branch pipe 832 is connected with a cyclone inlet 833 of a multi-tube cyclone separation zone 83. The upper part of the multi-tube cyclone separation zone 83 is provided with a central overflow port 834. The central overflow port 834 is connected with a converging branch pipe 835. The converging branch pipe 835 is connected with a converging main pipe 836. The bottom of the multi-tube cyclone separation zone 83 is provided with a underflow port 837. The underflow port 837 is connected with a sewage discharge main pipe 838.

[0060] As Figure 2As shown, the working method of the cleaning and regeneration device of the denitration catalytic filter bag is as follows: softened water enters the water tank for standby, the softened water in the water tank 1 enters the liquid preparation tank 2, the top of the liquid preparation tank 2 is provided with a chemical washing agent inlet for preparing the cleaning liquid; the liquid preparation tank 2 is provided with a liquid level meter 22, when the liquid level is too high, the liquid preparation tank 2 discharges the liquid to the clarifier 8 through the liquid discharge pipe; when the liquid level is too low, the liquid preparation tank 2 can be supplemented with water through the recovered liquid or the water tank; the liquid preparation tank 2 is provided with a stirrer 21 for stirring and mixing when preparing the cleaning liquid; the liquid preparation tank 2 is internally provided with a flow guide baffle 23, which is used to prevent the water / supplement, the recovered liquid and the chemical cleaning agent from being short-circuited to the subsequent system without being fully stirred and mixed after entering the liquid preparation tank during the liquid preparation process. The outlet of the liquid preparation tank 2 is provided with a filter 3 and a delivery pump 4, the cleaning liquid is sent to the ultrasonic cleaner 5 through the delivery pump 4 for ultrasonic cleaning, the ultrasonic cleaner 5 is provided with an external electric heater 56 and a circulating pump 57 for circulating and heating the cleaning liquid, and a temperature controller and a liquid level meter are arranged to realize automatic control of the temperature and the liquid level of the cleaning liquid. The waste liquid after ultrasonic cleaning is discharged from the bottom of the ultrasonic cleaner 5, pumped into the clarifier 8 through the waste liquid pump 7, and separated into clear liquid and sludge through the clarification and decontamination of the clarifier 8, the clear liquid is returned to the liquid preparation tank 2 through the liquid return pump 9 for reuse; and the sludge is discharged from the bottom of the system through the sludge discharge pipe of the clarifier 8. When the catalytic filter bag 6 is cleaned in the ultrasonic cleaner 5, it is reloaded into the catalytic filter bag device for continuous air drying and calcination, so as to realize the cleaning and regeneration of the catalytic filter bag 6.

[0061] The key links of the cleaning and regeneration device and the working method of the denitration catalytic filter bag are described in detail below.

[0062] (I) Cleaning liquid

[0063] The main function of the cleaning liquid is to dissolve, emulsify or disperse pollutants, and the formula needs to be designed according to the chemical properties (polarity / non-polarity, acidity / alkalinity, etc.) of the pollutants. The preparation of the cleaning liquid is completed in the liquid preparation tank 2. According to the pollution degree and deactivation reason of the catalytic filter bag, the cleaning liquid can be prepared accordingly, and the main cleaning and regeneration processes include:

[0064] (a) Water washing

[0065] Water washing is a relatively simple and effective cleaning and regeneration process that does not cause the loss of active components of the catalyst, especially when the catalytic filter bag 6 is blocked and deactivated by ammonium salt, the ammonium salt is easily dissolved in water and can be easily removed by water washing. Ultrasonic water washing can also remove most of the fly ash from the catalytic filter bag 6, even some fly ash that is not easily dissolved in water, because of the mutual friction between the water flow and the surface of the catalytic filter bag 6, the water molecules penetrate into the interior of the catalytic filter bag, reducing the adhesion between the catalytic filter bag 6 and the fly ash particles, so that the fly ash is stripped and removed.

[0066] Since the pollutants in the catalytic filter bag 6 are mostly basic inorganic salts, in order to ensure good solubility of the cleaning liquid, the cleaning liquid is prepared as a slightly acidic liquid, and the pH of the cleaning liquid is monitored in real time, and an appropriate amount of hydrochloric acid or other acidic substances is added to adjust the pH, and the pH of the cleaning liquid is preferably 6-7.

[0067] The surface tension of pure water is high, and the addition of a surfactant can reduce the surface tension and viscosity of the liquid, increase the transmission of ultrasonic vibration, promote cavitation effect and acoustic streaming effect, and make the cleaning effect more uniform; for some fly ash that exists in micropores, is not easy to dissolve, and is difficult to remove, such as alkaline earth metal salts (such as calcium sulfate, calcium carbonate), the removal effect can also be enhanced by adding a surfactant, such as using 1%wt hydroxyethylidene diphosphonic acid (HEDP) in a weak acid environment to increase the solubility of alkaline earth metals and to complex Ca 2+ , reduce the binding force between fly ash and the catalytic filter bag, help water molecules penetrate, diffuse, emulsify, and solubilize into the fly ash particles, thereby achieving the effect of removing fly ash, and ensuring that the vanadium and tungsten catalyst components are not lost.

[0068] (b) Acid washing

[0069] After the catalytic filter bag 6 is washed with ultrasonic water, the fly ash in the micropores of the catalyst surface and the poisoning elements adsorbed on the surface of the catalyst are mostly removed, but for catalysts with high alkaline poisoning, acid washing can be used to restore the specific surface area and surface acidity of the catalyst to the level of fresh catalyst, generate Lewis acid sites, and improve the denitration activity of the catalyst. At the same time, acid washing can further remove some water-insoluble metal oxides on the catalytic filter bag 6, such as CaO, As2O3, Fe2O3, etc. Acid washing can promote chemical reactions between these water-insoluble metal oxides and H + , increasing their solubility and effectively removing them from the catalyst micropores.

[0070] The chemical cleaning agent for acid washing can be inorganic acid or organic acid. The type and concentration of the acid have a significant impact on the cleaning and regeneration effect of the catalytic filter bag 6. Overly concentrated acid can strengthen cleaning but cause excessive loss of active components V and W; overly low concentration of acid reduces the removal rate of poisoning elements, especially for heavily poisoned catalysts, which does not have a significant regenerative effect, so it is very important to choose the right type and concentration of acid. Generally, for catalytic filter bags with deep alkaline poisoning, 2-3% nitric acid or a mixture of the same concentration of sulfuric acid can be used to significantly remove alkali metal ions; for catalytic filter bags with light alkaline poisoning, mild chemical cleaning agents such as acetic acid and oxalic acid with weak acidity can be used for gentle cleaning and regeneration to reduce the loss of active components of the catalyst.

[0071] In addition, the water, acetic acid and nitric acid complex solution can also regenerate the deactivated Pb catalyst, and the nitric acid solution can increase the surface area of the catalyst, produce new acid sites, and reduce the content of poisoning elements on the surface of the catalyst to the greatest extent, so that the activity of the catalyst is recovered to a certain extent.

[0072] (c) Alkaline washing

[0073] A certain concentration of alkaline solution such as NaOH and Na2CO3 can remove the acidic substances on the surface of the catalyst. For example, 1wt% NaOH solution has a good cleaning and regeneration effect on the arsenic (As) poisoned catalyst filter bag. Alkaline washing can cause a high loss of active substances V of the catalyst, and also introduce Na element deposition and secondary poisoning on the catalyst, so that the activity of the catalyst is recovered to a certain extent.

[0074] (d) Active component supplement

[0075] During the use of the catalyst filter bag and during the acid washing and alkaline washing, the active components of the catalyst are lost to a certain extent. The active component regeneration solution can be used to regenerate and supplement the catalyst filter bag, so that the poisoned or lost active components of the catalyst are effectively supplemented and the activity is recovered. For example, after mixing and roasting 1% ammonium metavanadate and 5% ammonium paratungstate solution, forming a catalyst powder, and uniformly mixing with polytetrafluoroethylene (PTFE) emulsion, hydroxyethyl cellulose, sodium methylsilicon, sodium dodecyl sulfate and ethanol, etc., the mixture is used as an active component regeneration solution to supplement the active components of the catalyst filter bag 6.

[0076] (II) Ultrasonic cleaner

[0077] Ultrasonic cleaning is to use the "cavitation effect" (impact force generated by the rupture of bubbles in the liquid) and "acoustic streaming effect" (micro-flow formed by high-frequency vibration of the liquid) produced by ultrasonic waves in the liquid, combined with mechanical vibration, emulsification, stirring and other auxiliary actions, to realize efficient stripping and removal of stains on the surface and gaps of the object. The core mechanism is cavitation effect and acoustic streaming effect. Cavitation effect forms micro-bubbles in the cleaning liquid, and the instantaneous impact force generated by the rupture of the bubbles strips the stains; the acoustic streaming effect is a "secondary flow" generated after the interaction of sound waves and fluid, which strengthens the cleaning effect. Compared with traditional cleaning methods, ultrasonic cleaning is labor-saving, fast, has good cleaning effect, low cost and easy automation, and is the preferred cleaning method in modern industry, especially suitable for cleaning objects with irregular shape and complex structure.

[0078] The ultrasonic cleaner 5 (such as Figures 2-3The ultrasonic cleaning device (as shown) is mainly composed of an ultrasonic generator 51, a transducer 52, a cleaning tank 53, a support frame 54, an external electric heater 56, a circulating pump 57, and the like. The ultrasonic generator 51 is a high-frequency electric signal generating device; the transducer 52 functions to convert electric energy into ultrasonic wave vibration, and further drive the cleaning liquid to generate "cavitation effect" and "acoustic streaming effect"; the cleaning tank 53 is a container for containing the cleaning liquid and the cleaning workpiece; the support frame 54 is used for supporting, fixing and rotating the cleaning workpiece. The ultrasonic generator 51 sends the ultrasonic oscillation signal to the transducer 52, the transducer 52 receives the instruction and generates high-frequency oscillation acting on the cleaning liquid in the cleaning tank 53, the cleaning liquid generates cavitation effect and acoustic streaming effect by vibration, constantly flushes the catalytic filter bag 6 fixed and supported on the support frame 54, causes the adhered dirt to vibrate and fall off; the external electric heater 56 and the circulating pump 57 are used for circulating and heating the cleaning liquid, so as to strengthen the dissolution and peeling of the dirt, and further improve the cleaning effect.

[0079] (1) Design of ultrasonic frequency and acoustic intensity

[0080] The ultrasonic frequency is one of the core parameters affecting the ultrasonic cleaning effect. Different frequencies are suitable for cleaning different types of workpieces. Selecting a suitable frequency can balance the cleaning efficiency, cleanliness, and protect the cleaning workpiece from being damaged. The ultrasonic frequency range for cleaning is generally 20KHz-200KHz, among which 20KHz-50KHz is low-frequency cleaning, and 50KHz-200KHz is high-frequency cleaning. The strong impact force of low frequency is suitable for removing stubborn, thick or closely adhered contaminants, so it is more suitable for cleaning workpieces of impact-resistant materials or rough surfaces. Compared with low-frequency cleaning, high-frequency cleaning has soft vibration and less damage to fragile workpieces, and is suitable for cleaning precision workpieces and fragile workpieces with high cleaning precision and workpiece protection, such as electronic components, optical lenses, ultrafiltration membranes, etc. In practical application, a suitable frequency should be selected according to the material of the cleaning workpiece and the type of contaminants. The inner bag 61 of the catalytic filter bag of the present application can be cleaned at a high frequency of 50-100KHz. The outer bag 62 is composed of a film and is relatively easy to damage, so a higher frequency of 100-200KHz can be used for cleaning.

[0081] The acoustic intensity refers to the power per unit area of the ultrasonic wave transmission (unit: W / cm 2 ), and is one of the key parameters determining the cleaning effect and cleaning time. The acoustic intensity drives the cavitation effect, and its size directly determines the number of cavitation bubbles, the collapse energy and the action intensity. When the acoustic intensity is low (such as <0.1 W / cm 2 ), it is difficult to form effective cavitation bubbles in the liquid, or the number of cavitation bubbles is extremely small and the collapse energy is weak, so the cleaning effect is poor. When the acoustic intensity is moderate (0.3~1.5 W / cm 2 ), the number of cavitation bubbles is moderate, and the cavitation bubbles can collapse stably and release enough energy to peel off stubborn dirt, while avoiding damage to the workpiece. When the acoustic intensity is too high (such as >2 W / cm2 ): too large cavitation bubble density will interfere with each other and even "gather", resulting in some cavitation bubbles before the collapse of the mutual fusion, but reduce the cavitation bubble collapse energy; in addition, too high sound intensity will trigger "cavitation saturation", the number of cavitation bubbles that can be formed in the liquid to the limit, the excess energy into heat or meaningless turbulence, not only can not improve the cleaning efficiency, but also may cause severe shock waves and high temperature damage to the cleaning piece. For catalytic filter bag 6, with low sound intensity 0.1~1.5W / cm 2 ; the selected range is appropriate to prevent damage to the high sound intensity, the inner bag 61 can be 0.5~1.5W / cm 2 ; the outer bag 62 is 0.1~0.5W / cm 2 .

[0082] (2) The arrangement and selection of the transducer

[0083] The sound field distribution refers to the distribution of acoustic parameters such as sound pressure, sound intensity, and phase at different positions and times when the sound wave propagates in the cleaning tank, which describes how the sound energy is distributed and changed in space. The sound field distribution directly affects the uniformity, efficiency, cleanliness of cleaning, and possible damage caused by excessive vibration, and an unreasonable sound field distribution appears "sound field blind area" or "energy focusing area" that causes damage to the cleaning piece.

[0084] The arrangement and arrangement density of the transducer 52 are the key means to control the sound field distribution. Taking the Φ160mm 6000 catalytic filter bag 6 cleaning as an example, as shown in Figures 4-6 , the cleaning tank 53 is designed as a rectangular deep tank, which can accommodate 23 catalytic filter bags 6 at a time, and the catalytic filter bags 6 are placed vertically in the cleaning tank 53 with the bag opening upwards and the bag bottom downwards. Since the catalytic filter bag 6 is a long cylindrical object, the transducer 52 is preferably arranged on the four sides of the cleaning tank 53, that is, the transducer 52 is uniformly arranged along the length direction of the catalytic filter bag 6 to ensure uniform and full coverage of the sound wave along its axial direction, and the distance between the transducer 52 and the catalytic filter bag 6 is preferably 10~30cm.

[0085] The transducers 52 are arranged in a layered staggered manner, which aims to break the regularity of sound wave superposition and reduce interference. By increasing the number of transducer 52 arrangements, the power of a single transducer 52 can be reduced, while the total power of the catalytic filter bag 6 cleaning can be ensured, avoiding damage to the filter bag caused by excessive local sound intensity; however, the transducers 52 cannot be arranged too densely, which will increase the probability of sound wave cross superposition. The staggered angle between layers of transducers 52 is 45°-60°, and the staggered arrangement is repeated layer by layer until the bottom of the bag is reached. The spacing between layers of transducers 52 is not completely equal, and the spacing between layers can be 20 cm, 25 cm, 20 cm, and so on, which is alternately designed to break the fixed period of sound wave interference. The transducers 52 in different layers also use different ultrasonic frequencies to avoid superposition of the same frequency and suppress the generation of standing waves: for example, the first, second, and third layers use 60 kHz, 60.5 kHz, and 61 kHz frequencies, respectively, in an alternating design.

[0086] Generally, the power of a single transducer 52 is 50-500W, and the greater the power of a single transducer 52, the higher the energy concentration, which can easily cause damage to the cleaning parts. For large industrial cleaning tanks (volume ≥1000L), transducers 52 of 100W-500W specifications are commonly used; the specific type should be selected in combination with the material of the cleaning parts. For catalytic filter bags 6, the power of a single transducer 52 is selected in a lower range (100W-200W) to avoid damage to the catalytic filter bags.

[0087] In order to strengthen the internal cleaning of the catalytic filter bag 6, a cylindrical transducer 55 (as shown in Figure 6 ) can also be arranged axially in each catalytic filter bag 6. The cylindrical transducer 55 extends into the interior along the center from the mouth of the catalytic filter bag 6, radiates sound waves to the inner wall, and forms an "inside-out" cleaning effect with the transducers 52 arranged around the side.

[0088] (3) Support frame design

[0089] Before ultrasonic cleaning, the catalytic filter bag 6 needs to be erected in the cleaning tank 53. The support frame 54 is designed to solve the problem of disordered stacking of the catalytic filter bag 6 in the cleaning tank 53, achieve orderly separation of the catalytic filter bag 6, and ensure smooth flow of the cleaning liquid, thereby ensuring effective ultrasonic cleaning.

[0090] The support frame 54 is designed according to the unique structure of the catalytic filter bag 6, mainly including: an annular ring 541, a support flower plate 542, a support angle steel 543, etc., and the structure is as shown in Figure 6A circle of support angle steel 543 is welded around the upper part of the inner wall of the rectangular tank body of the cleaning tank 53, which serves to support the support flower plate 542 and reinforce the cleaning steel plate 531; the support flower plate 542 is placed on the support angle steel 543 and connected with the support angle steel 543 through bolts; the support flower plate 542 is composed of a plurality of round holes (support flower plate holes), and a V-shaped groove is opened around the periphery of each round hole of the support flower plate 542, which is used for buckling connection with the annular ring 541 with a V-shaped convex groove; the inner hole diameter of the annular ring 541 matches the bulging ring 63 at the bag opening of the catalytic filter bag, so as to realize the close connection of the catalytic filter bag 6 and the annular ring 541.

[0091] The specific steps of erecting the catalytic filter bag 6 on the support frame 54 are as follows: ①Take a catalytic filter bag 6 to be cleaned, and compress the bag opening spring bulging ring 63 by external force to make it put into the round hole of the annular ring 541; ②After putting into the round hole of the annular ring 541, the external force is removed, and the bulging ring 63 restores to the original state by elasticity and is tightly clamped on the wall of the round hole of the annular ring 541; ③The bag bottom and bag body of the catalytic filter bag 6 clamped with the annular ring 541 are sequentially passed through the holes of the support flower plate 542, and the catalytic filter bag 6 is vertically placed in the cleaning tank 53 in a way that the bag opening is upward; ④The V-shaped convex groove of the annular ring 541 is buckled into the V-shaped groove slide rail of the support flower plate 542, and the support and fixation and the rotary cleaning of the catalytic filter bag 6 are realized through the design of the V-shaped slide rail.

[0092] The rotary slide rail design of the support frame 54 effectively enhances the cleaning effect of the catalytic filter bag 6, because: ①During the rotation of the catalytic filter bag 6, the surface of the catalytic filter bag 6 will periodically enter different sound field areas, avoiding incomplete local cleaning caused by uneven sound field; ②The relative motion between the rotating surface of the catalytic filter bag 6 and the cleaning liquid generates additional centrifugal force and shear force, and the mutual superposition of such mechanical force and cavitation effect and acoustic flow effect can more efficiently strip the dirt from the surface; ③Rotation can constantly update the cleaning liquid of each part of the catalytic filter bag 6, strengthen the turbulent flow and circulation of the cleaning liquid, and avoid local retention of high-concentration dirt cleaning liquid.

[0093] (4) Automatic control of cleaning liquid temperature and liquid level

[0094] Heating the cleaning liquid can promote the dissolution and stripping of the dust and ammonium salt on the catalytic filter bag 6, and especially when a large amount of ABS (sulfuric acid hydrogen ammonia) is enriched, heating the cleaning liquid to 40-80℃ can significantly improve the cleaning effect of the catalytic filter bag. The present application adopts an external electric heater circulating heating mode (as shown in Figure 2 ), and is equipped with a cleaning tank temperature controller and a liquid level meter to automatically control the temperature and liquid level of the cleaning liquid. Compared with the method of heating the cleaning liquid by directly inserting an electric heating tube or providing an electric heating plate on the wall of the cleaning tank, the external electric heater circulating heating has the advantages of fast temperature rising response, uniform heating, easy adjustment, etc., and avoids the damage of the catalytic filter bag 6 caused by local high temperature of the electric heating tube / plate.

[0095] The specific working process of the design of the external electric heater circulating heating cleaning liquid is: ① When the catalytic filter bag 6 is installed in the cleaning tank 53, open the outlet valve 561 of the liquid preparation tank 2, open the liquid supplement valve 562, and send the cleaning liquid prepared in the liquid preparation tank 2 into the cleaning tank 53 through the delivery pump 4 until the liquid level reaches the designed liquid level (such as about 50 mm below the support flower plate 542); close the outlet valve 561 of the liquid preparation tank, and close the liquid supplement valve 562; ② open the cleaning liquid input valve 563, the output valve 564, the external electric heater 56 and the circulating pump 57, realize the circulating heating of the cleaning liquid by the external electric heater 56, until the cleaning liquid in the cleaning tank 53 reaches the designed temperature, in order to ensure that the cleaning liquid is uniformly heated and avoid short circuit of the circulation, the cleaning liquid heated by the external electric heater 56 is uniformly distributed to the bottom of the cleaning tank 53 through the multi-tube flow distribution pipe 58; ③ when the designed temperature and liquid level reach the designed value, the catalytic filter bag 6 starts to clean according to the set cleaning process and steps, at the same time, the temperature control instrument arranged on the cleaning tank 53 automatically controls the start and stop of the external electric heater 56 and heating, so that the cleaning liquid is maintained in the designed temperature range until the cleaning is completed; ④ when the salinity of the cleaning liquid sludge is too high or low temperature cleaning is used, close the cleaning liquid input valve 563 and the output valve 564, open the discharge valve 565, part or all of the cleaning liquid is discharged through the discharge valve 565, and open the outlet valve 561 of the liquid preparation tank and the liquid supplement valve 562 to input the cleaning liquid in the liquid preparation tank 2 into the cleaning tank 53.

[0096] (Three) clarifier

[0097] In the process of cleaning and regenerating the catalytic filter bag 6 in the ultrasonic cleaner 5, the ammonium salt and dust deposited on the catalytic filter bag 6 will be continuously stripped and removed, and transferred to the cleaning liquid to form waste liquid; the waste liquid is pumped to the clarifier 8 through the waste liquid pump 7 through the discharge valve 565 at the bottom of the cleaning tank 53. The waste liquid is mainly composed of suspended solids, ammonium salt, sulfate, chloride and heavy metals. These crystalline salts, insoluble salts and impurities need to be precipitated, clarified and liquid-solid separated in the clarifier 8 to meet the further recycling and discharge requirements.

[0098] On-site cleaning and regeneration is a process of cleaning and regenerating each bin on site, and when one bin completes cleaning and regeneration, it returns to the working state; the regeneration equipment moves to the next bin for cleaning and regeneration, therefore, the clarifier 8 is required to have the characteristics of compact structure, easy to move, flexible and convenient on the basis of ensuring efficient clarification and separation. The traditional clarifier 8 design uses horizontal flow sedimentation technology, which has the disadvantages of large occupation area, low treatment efficiency and difficulty in effectively separating fine particles, which is not suitable for catalytic filter bag waste liquid recycling and treatment, and a skid-mounted clarifier 8 is needed, which is efficient in separation, compact in structure, easy to move and transport.

[0099] The clarifier 8 mainly consists of three parts (as shown in Figures 7-9 ): a mixed flocculation zone 81, a inclined plate sedimentation zone 82, and a multi-tube cyclone separation zone 83. The waste liquid first enters the mixed flocculation zone 81, is fully stirred and coagulated with the chemical agent to form alum flowers, and then slowly enters the inclined plate sedimentation zone 82 for preliminary precipitation; and then enters the multi-tube cyclone separation zone 83 to strengthen the solid-liquid separation and achieve efficient removal of fine particles from the waste liquid.

[0100] The working process of the mixed flocculation zone 81 is completed in two steps: (a) neutralization reaction stage: first, NaOH lye is added to the waste liquid as a neutralizing agent and a precipitating agent, the pH of the waste liquid is adjusted to 9.0~9.5, so that most heavy metal ions generate insoluble hydroxides and precipitate in the alkaline environment; at this time, Pb 2+ , Hg 2+ still dissolve in the waste liquid in the form of ions, and the addition of organic sulfide (TMT15) can make it react with Pb 2+ , Hg 2+ to form insoluble sulfides and precipitate. (b) mixed coagulation stage: a coagulant is added to make the hydroxides, sulfides, and suspended solids precipitated in the neutralization reaction further flocculate and precipitate, and the coagulant is precipitated by a series of reactions such as electric neutralization, compressed double electric layer, adsorption bridging, and roll-sweeping precipitation, so that the particles in the waste liquid form alum flowers and precipitate. Common coagulants are two categories of inorganic metal salts and organic high molecular polymers. Inorganic metal salts are mainly high-valent metal salts such as iron and aluminum, and common ones are PAC (polyaluminum chloride), PAS (polyaluminum sulfate), PAFS (polyaluminum ferric sulfate), etc.; organic high molecular polymers are mainly polyacrylamide (PAM), methylene polyacrylamide (MPAM), and polyethylene oxide (PEO), etc., among which PAM is the most commonly used. The combination of inorganic metal salts and organic high molecular polymer coagulants can effectively realize the settlement of suspended solids and the precipitation of hydroxides, such as the combination of PAFS and PAM, PAFS is added in the flocculation tank to make the fine particles in the waste liquid coagulate into large particles; and then anionic PAM (polyacrylamide) is added to further reduce the surface tension of the particles, so that the fine flocculation grows into solid and easy-to-precipitate alum flowers (flocculation).

[0101] As shown in Figure 7As shown, the mixed flocculation zone 81 is provided with a dosing port 811 for gradually adding lye-organic sulfur-flocculants; the mixed flocculation zone is provided with a stirrer 812, which aims to fully mix the waste liquid and the added reagents to form alum flowers; the mixed flocculation zone is provided with a baffle 813, which aims to: (a) prevent the short-circuiting of waste liquid that has not been fully mixed into the inclined plate settling zone; (b) provide an obstacle to the free movement of particles in water, which is conducive to the adhesion of particulate matters to the baffle and the formation of mud cakes for sedimentation and discharge. After the waste liquid passes through the mixed flocculation zone 81, a large number of alum flowers are generated, which then enter the water distribution tank 814. The water distribution tank 814 functions to buffer the waste liquid before it enters the inclined plate settling zone 82, so as to achieve uniform water distribution. Meanwhile, the water distribution tank 814 is provided with an overflow baffle 815, which aims to ensure that the suspended matters on the overflow baffle 815 can all flow out of the system when the suspended matter discharge port 816 is opened.

[0102] The inclined plate settling zone 82 is provided with a plurality of inclined plates 823, which form an angle of 60° with the horizontal plane. The waste liquid is uniformly distributed to the water distribution area 822 through the water distribution port 821, and then flows upward in a countercurrent manner. A large number of alum flowers are blocked by the wall surface of the inclined plates 823 and deposited in the bottom sludge hopper 827, and then discharged through the sludge pipe 828. After the waste liquid is filtered and settled through the inclined plates 823, it enters the clear water area 824. The clear water area is provided with a triangular weir 825 at the upper portion, and the clear water overflows through the triangular weir 825 to the water outlet tank 826, so as to complete the solid-liquid primary separation of the inclined plate settling zone 82.

[0103] The multi-inclined plate design of the inclined plate settling zone 82 greatly reduces the sedimentation hydraulic radius, lowers the Reynolds number R, and increases the Froude number Fr, so as to meet the requirements of water flow stability and laminar flow, which is conducive to the clarification and sedimentation of the waste liquid. The main advantages are: (a) the multi-inclined plate design increases the wetted perimeter and reduces the hydraulic radius, which significantly reduces the alum flower sedimentation distance, so that more small particles can be precipitated, and the treatment capacity is 3-5 times that of an ordinary horizontal flow sedimentation tank; (b) the multi-inclined plate design increases the water flow resistance in the sedimentation tank, so that the flow field distribution in the sedimentation tank is uniform, the laminar flow state is good, and it is conducive to particle sedimentation; (c) it can meet the pretreatment of waste liquid with high turbidity and high mud sand, and is not prone to equipment blockage, stable operation, and simple equipment; (d) the water flow in the sedimentation tank is arranged in a countercurrent manner from bottom to top, so that the mud and water separation effect is good; (e) the structure is compact and occupies a small area, so that the on-site waste liquid can be treated in a timely manner.

[0104] In theory, the water flow in the inclined plate sedimentation zone 82 is in a laminar flow state. However, in reality, there are slight pulsations in the water flow. When the large flocs in the inclined plate move relative to the water during sedimentation, small eddies are generated behind the floc particles. The movement generated by these small eddies causes water flow pulsations. These pulsations have no effect on the large floc particles, but they play a supporting role for the small particles, thus having an adverse effect on sedimentation. Therefore, in order to improve the solid-liquid separation efficiency, the waste liquid enters the multi-tube cyclone separation zone 83 for further separation after initial sedimentation in the inclined plate sedimentation zone 82.

[0105] The multi-tube cyclone separation zone 83 consists of multiple cyclones arranged in parallel, employing a compact skid-mounted design, such as... Figure 8 As shown, conventional hydrocyclones have low separation efficiency when treating waste liquids with small particle sizes and low concentrations. This invention employs a multi-tube hydrocyclone separation skid design to achieve efficient separation of fine particles, even micron-sized particles. The hydrocyclone uses a multi-tube design because the formula for calculating centrifugal force shows that the magnitude of the centrifugal force on a droplet of a certain mass is inversely proportional to its radius of rotation; the smaller the radius, the greater the centrifugal force, and the higher the separation efficiency. The multi-tube design significantly improves the solid-liquid separation efficiency of the equipment. The multi-tube hydrocyclone separator has advantages such as high separation efficiency, simple structure, low manufacturing cost, small equipment size, easy operation and maintenance, and resistance to clogging.

[0106] The multi-tube hydrocyclone separator operates as follows: Waste liquid first enters the main distribution pipe 831 under pressure, then is evenly distributed to each hydrocyclone inlet 833 via the distribution branch pipe 832, injected tangentially into the hydrocyclones, generating high-speed rotation within the cyclone chamber. The light phase, clear water, experiences less inertial force under the centrifugal cyclone field, moving towards the central axis region and overflowing from the central overflow port 834, then flowing through the confluence branch pipe 835 to the main confluence pipe 836. The heavy phase, fine particles, move axially downwards under the centrifugal cyclone field, experiencing greater inertial force and generating radial acceleration, moving towards the conical section wall and flowing out from the bottom outlet 837. They then converge into the main drain pipe 838 for discharge, thus achieving liquid-solid separation of the waste liquid. After clarification by the clarifier 8, the clear water is returned to the distribution tank 2 via the return pump 9, thus achieving waste liquid reuse.

[0107] In order to improve the separation efficiency, the tangential water flow velocity of the cyclone is large, and the equipment is prone to vibration, so the support and limiting design of the skid is also important. The back plate 839, the bottom plate 8310 are provided as the main steel structure and support of the skid; the vertical support plate one 8311 is connected with the back plate 839 and the bottom plate 8310, and two pieces are symmetrically arranged to realize the limiting and supporting of the blowdown main pipe 838 and the liquid distribution main pipe 831; the collecting main pipe 836 is an L-shaped elbow pipe, which is divided into a vertical section and a horizontal section; the inlet end of the vertical section of the collecting main pipe 836 is connected with the outlet of the collecting branch pipe 835, and the other end of the vertical section pipe is connected with the horizontal section pipe of the collecting main pipe 836; the vertical support plate two 8312 is connected with the back plate 839 and the bottom plate 8310, and is used for limiting and supporting the horizontal section pipe of the collecting main pipe 836; the horizontal support plate three 8313 is connected with the back plate 839, and supports and limits each cyclone through the support lug 8315 arranged on each cyclone; the horizontal support plate four 8314 is connected with the back plate 839, and limits the collecting main pipe 836.

[0108] (Four) cleaning and regeneration method of catalytic filter bag

[0109] The catalytic filter bag device currently used in industry is designed in a separate bin, and the on-site regeneration design of the catalytic filter bag in the application is to make full use of the existing bin structure, that is, when one bin is cleaned and regenerated, the other bins are in working state. The specific steps are as follows: ①Before cleaning and regeneration of one catalytic filter bag 6 bin, compressed air is used to blow dust off the surface of the catalytic filter bag 6; ②The inlet and outlet flue gas damper doors of the bin are closed, the air inlet and outlet damper doors are opened, and ambient air is introduced to completely replace the flue gas in the bin with air; ③The air inlet and outlet damper doors are closed, the top cover of the bin is opened, and the catalytic filter bag 6 in the bin is taken out; ④According to the reasons and degree of deactivation of the catalytic filter bag 6, the cleaning liquid is prepared in the liquid preparation tank 2 in advance, and the cleaning and regeneration process combination scheme and cleaning steps are formulated; ⑤According to the prepared cleaning liquid and formulated cleaning process and steps, step-by-step cleaning is carried out in the ultrasonic cleaner 5, and the cleaning steps include soaking, rough cleaning, fine cleaning and rinsing; ⑥When the cleaning and regeneration is completed, the catalytic filter bag 6 is installed back into the catalytic filter bag device, and the top cover of the bin is closed; the air inlet and outlet damper doors are opened, and the catalytic filter bag is dried; the air is heated by an electric heater, and the power of the electric heater is adjusted to ensure that the outlet air temperature of the bin is not lower than 120℃, and the drying time is not less than 2-3h; ⑦If the active component supplement process (d) is used for cleaning and regeneration, the catalytic filter bag 6 after drying needs to be calcined to improve the catalytic activity; the air temperature is increased to 300℃-550℃ by increasing the power of the electric heater or circulating the heated air, so as to meet the temperature requirement of the catalyst calcination; ⑧When the catalytic filter bag 6 drying and calcination are completed, the air inlet and outlet damper doors are closed, the flue gas inlet and outlet damper doors are opened, and the working state of the catalytic filter bag in the bin is restored.

[0110] The cleaning and regeneration process of the catalytic filter bag 6 includes water washing (a), acid washing (b), alkali washing (c), and active component supplementing (d). The cleaning and regeneration process combination is designed according to the reasons for deactivation and the degree of poisoning of the catalytic filter bag 6. The preferred cleaning and regeneration process is the most effective and economical ultrasonic water washing method (a), which can dissolve and remove most of the dirt on the catalytic filter bag 6. For example, if the common causes of catalytic filter bag deactivation are ammonium salt and fly ash blockage, then ultrasonic water washing (a) can effectively regenerate and restore the catalytic filter bag. If the main cause of catalytic filter bag deactivation is dust physical blockage and alkali poisoning, then the cleaning and regeneration process combination can be (a) + (b) or (a) + (b) + (d). If the deactivation of the catalytic filter bag is caused by heavy metal arsenic poisoning, then the cleaning and regeneration process combination can be (a) + (c) + (b) + (d).

[0111] The ultrasonic water washing (a) is completed in the ultrasonic cleaner 5, and the cleaning liquid used is pure water or pure water + surfactant. The cleaning steps are: soaking → rough washing → fine washing → rinsing: ① Soaking stage: turn off the ultrasonic + pre-soak; after the cleaning liquid is input into the cleaning tank 53 to the designed liquid level, start soaking; through the soaking action of the cleaning liquid, the structure of the dirt becomes loose, the adhesion of the dirt surface is reduced, and the subsequent use of smaller intensity ultrasonic can meet the requirements of dirt peeling and removal, avoiding the damage risk of high-intensity ultrasonic impact on the catalytic filter bag. ② Rough washing stage: turn on low-frequency ultrasonic + low-speed rotation, use low-frequency ultrasonic to generate strong impact force to peel off large pollutants; use low-speed rotation to help remove large particles from the catalytic filter bag 6. ③ Fine washing stage: turn on high-frequency ultrasonic + high-speed rotation, use high-frequency ultrasonic to better remove small particles in the micropores of the catalytic filter bag 6; use high-speed rotation to make the cleaning liquid produce uniform flow to ensure that each micropore is fully soaked and flushed by the cleaning liquid. ④ Rinsing stage: turn off the ultrasonic + high-speed rotation, and replace the cleaning liquid with pure water; use high-speed rotation to enhance the rinsing effect of pure water on the catalytic filter bag.

[0112] Most of the dirt on the catalytic filter bag 6 can be removed by ultrasonic water washing (a), so if further acid washing (b) or alkali washing (c) process combination is needed, the steps of soaking → fine washing → rinsing can be used to save the rough washing stage; the active component supplementing (d) uses ultrasonic immersion method to regenerate and supplement the active components of the catalytic filter bag, so the steps of soaking → fine washing are used. In summary, according to the pollution degree and poisoning situation of the catalytic filter bag, the corresponding cleaning liquid is prepared in the liquid preparation tank 2, the cleaning and regeneration process combination (water washing, acid washing, alkali washing, and active component supplementing) is designed, and the cleaning steps (soaking → rough washing → fine washing → rinsing) are designed to maximize the efficient cleaning and regeneration of the catalytic filter bag.

[0113] In the catalytic filter bag cleaning process of soaking, rough cleaning, fine cleaning and rinsing, with the continuous accumulation of dirt dissolution, the density and viscosity of the cleaning liquid continuously rise, the cavitation effect and acoustic streaming effect weaken, and the cleaning effect becomes poor. Therefore, the cleaning liquid needs to be supplemented and the aged cleaning liquid needs to be discharged in time. The aged cleaning liquid forms waste liquid and is discharged from the bottom discharge valve 565 of the cleaning tank 53, pumped by the waste liquid pump 7 to the clarifier 8. The waste liquid is coagulated, precipitated and solid-liquid cyclone separated in the clarifier 8, and the solid particles are discharged in the form of sludge from the sludge discharge pipe 828 and the blowdown main pipe 839; and the separated clear liquid is returned to the liquid preparation tank 2 for continuous use.

[0114] The above-described embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A cleaning and regenerating device for a denitration catalytic filter bag, characterized by: The system comprises a water tank (1), a liquid preparation tank (2), a filter (3), a delivery pump (4), an ultrasonic cleaner (5), a waste liquid pump (7), a clarifier (8) and a liquid return pump (9) connected in sequence through pipelines, the outlet of the liquid return pump (9) is connected with the liquid recovery inlet of the liquid preparation tank (2), the liquid discharge outlet of the liquid preparation tank (2) is connected with the liquid discharge inlet of the clarifier (8), the pipeline between the delivery pump (4) and the bottom inlet of the ultrasonic cleaner (5) is sequentially provided with a liquid preparation tank outlet valve (561) and a liquid supplement valve (562), the top outlet of the ultrasonic cleaner (5) is connected with the inlet of an external electric heater (56) and the pipeline between the liquid preparation tank outlet valve (561) and the liquid supplement valve (562), the outlet of the external electric heater (56) is connected with a circulating pump (57), the outlet of the circulating pump (57) is connected with an output valve (564), and the outlet of the output valve (564) is connected with the bottom inlet of the ultrasonic cleaner (5); The ultrasonic cleaner (5) comprises a cleaning tank (53), the upper part of the cleaning tank (53) is provided with a support frame (54), and a plurality of transducers (52) are arranged on the cleaning tank (53) and connected with an ultrasonic generator (51); The cleaning tank (53) is a rectangular deep tank and can accommodate a plurality of catalytic filter bags (6), the catalytic filter bags (6) are vertically placed in the cleaning tank (53) with the bag mouths upward and the bag bottoms downward, the transducers (52) are arranged on the four sides of the cleaning tank (53) and are uniformly arranged along the length direction of the catalytic filter bags (6), and the distance between the transducers (52) and the catalytic filter bags (6) is 10-30 cm; The support frame (54) comprises a ring (541), a support lath (542) and a support angle steel (543), the support angle steel (543) is located on the upper part of the inner wall of the tank body of the cleaning tank (53), the support lath (542) is installed on the support angle steel (543) through bolts, a plurality of support lath holes (5421) are arranged on the support lath (542), a V-shaped groove, i.e., a support lath rotating slide rail (5422), is arranged around the support lath hole (5421), a V-shaped protrusion is arranged on the bottom surface of the ring (541), the V-shaped protrusion is connected with the support lath rotating slide rail (5422) in a buckling mode, and the inner hole diameter of the ring (541) matches the ring (63) of the catalytic filter bag (6); The clarifier (8) comprises a mixed flocculation zone (81), an inclined plate sedimentation zone (82) and a multi-pipe cyclone separation zone (83), and the bottom of the mixed flocculation zone (81) and the inclined plate sedimentation zone (82) is provided with a sludge hopper (827) and a sludge discharge pipe (828); The mixed flocculation zone (81) is provided with a dosing port (811) and a stirrer (812), the outlet of the mixed flocculation zone (81) is provided with a baffle (813), the rear of the baffle (813) is a water distribution tank (814), and the upper part of the water distribution tank (814) is provided with an overflow baffle (815) and a suspended solid discharge port (816).

2. The cleaning and regenerating device of the denitration catalytic filter bag according to claim 1, characterized in that: The transducers (52) are arranged in a layered staggered manner, the staggered angle between the transducers (52) of different layers is 45°-60°, the distance between the transducers (52) of different layers is not completely equal, and the transducers (52) of different layers adopt different ultrasonic frequencies.

3. The device for cleaning and regenerating the denitration catalytic filter bag according to claim 1, characterized in that: The catalytic filter bag (6) is provided with a columnar transducer (55) therein, and the columnar transducer (55) is connected with the ultrasonic generator (51).

4. The device for cleaning and regenerating the denitration catalytic filter bag according to claim 1, characterized in that: The inclined plate sedimentation zone (82) is provided with a water distribution port (821) below the front part, a water distribution area (822) behind the water distribution port (821), a plurality of inclined plates (823) above the water distribution area (822), a clear water area (824) above the inclined plates (823), a triangular weir (825) above the clear water area (824), and a water outlet groove (826) above the rear part of the inclined plate sedimentation zone (82), wherein the water outlet groove (826) is connected with a liquid distribution main pipe (831).

5. The device for cleaning and regenerating the denitration catalytic filter bag according to claim 4, characterized in that: The liquid distribution main pipe (831) is connected with a plurality of liquid distribution branch pipes (832), each of the liquid distribution branch pipes (832) is connected with a cyclone inlet (833) of a multi-pipe cyclone separation zone (83), the upper part of the multi-pipe cyclone separation zone (83) is provided with a central overflow port (834), the central overflow port (834) is connected with a flow collection branch pipe (835), the flow collection branch pipe (835) is connected with a flow collection main pipe (836), the bottom part of the multi-pipe cyclone separation zone (83) is provided with a underflow port (837), and the underflow port (837) is connected with a blowdown main pipe (838).

6. The working method of the cleaning and regenerating device of the denitration catalytic filter bag according to any one of claims 1-5, characterized in that: The softened water enters a water tank (1) for standby, the softened water in the water tank (1) enters a liquid preparation tank (2), chemical washing agents are poured into the liquid preparation tank (2) through a chemical washing agent pouring port on the top of the liquid preparation tank (2), and cleaning liquid is prepared; The liquid preparation tank (2) is provided with a liquid level meter (22), when the liquid level is too high, the liquid preparation tank (2) discharges liquid to a clarifier (8) through a liquid discharge pipe, and when the liquid level is too low, the liquid preparation tank (2) can be supplemented with water through recovered liquid or the water tank (1); The cleaning liquid in the liquid preparation tank (2) is sent to an ultrasonic cleaner (5) through a delivery pump (4) to perform ultrasonic cleaning, the ultrasonic cleaner (5) circulates and heats the cleaning liquid through an external electric heater (56) and a circulating pump (57), and a temperature controller and a liquid level meter are arranged to realize automatic control of the temperature and the liquid level of the cleaning liquid; the waste liquid after ultrasonic cleaning is discharged from the bottom of the ultrasonic cleaner (5), pumped into the clarifier (8) through a waste liquid pump (7), and separated into clean liquid and sludge through the clarification and decontamination of the clarifier (8); the clean liquid is sent back to the liquid preparation tank (2) through a liquid return pump (9) for reuse; and the sludge is discharged from the bottom of the system through a sludge discharge pipe of the clarifier (8).

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