Catalyst deashing device and deashing method, SCR denitration deashing system and deashing method, desulfurization and denitration system and operation method

Abstract

The invention belongs to the technical field of flue gas treatment, and particularly relates to a catalyst ash removal device and method, an SCR denitration and ash removal system and method, a desulfurization and denitration system and an operation method. The catalyst ash removal device comprises an ash removal gas source and at least one ash removal unit. The SCR denitration ash removal system comprises the catalyst ash removal device. The desulfurization and denitrification system comprises the SCR denitrification and ash removal system. The catalyst ash removal device provided by the invention is used for removing ash of the catalyst in the SCR reactor in real time, and the catalytic efficiency of the catalyst is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flue gas treatment, and particularly relates to a catalyst ash cleaning device and an ash cleaning method, an SCR denitration ash cleaning system and an ash cleaning method, a desulfurization and denitration system and an operation method. Background Art

[0002] SDS (spray dry de-sulfurization technology, flue gas dry desulfurization process by duct injection) desulfurization + bag filter + SCR (selective catalytic reduction) denitration is a commonly used flue gas desulfurization and denitration process at present. In this process, sulfur dioxide in the flue gas is first removed by SDS, then filtered and purified by a bag filter, and the purified flue gas is then subjected to SCR denitration to remove nitrogen oxides in the flue gas, further purifying the flue gas. The SCR reactor in this process mostly adopts a multi-unit independent parallel operation mode, each unit has an independent inlet valve and outlet valve, and each unit generally has 2 to 4 layers of honeycomb catalysts. The flue gas to be denitrified enters from the upper part of the SCR denitration reactor after being mixed with externally injected ammonia. After passing through the denitration catalyst, nitrogen oxides in the flue gas react with ammonia under the action of the catalyst to generate nitrogen. The main chemical reaction equation in the reaction process is as follows: 4NO x + 4NH3 + O2 → 4N2 + 6H2O. The SCR reactor generally uses an acoustic soot blower to clean the dust on the surface of the catalyst, avoiding the situation of increasing the resistance of the SCR reactor due to catalyst blockage, thereby affecting the denitration effect.

[0003] However, in the above-mentioned flue gas desulfurization and denitration process of SDS + bag filter + SCR, it is inevitable that the ash cleaning bag of the ash cleaner is damaged or for other reasons, a large amount of desulfurized ash after SDS desulfurization enters the SCR reactor along with the flue gas. In the case of a large amount of desulfurized ash, the acoustic soot blower cannot clean the desulfurized ash on the surface of the SCR catalyst in time and quickly, resulting in the continuous accumulation of desulfurized ash on and inside the catalyst surface, and mainly on the surface (most of the ash is on the surface of the honeycomb denitration catalyst and at 1 cm to 5 cm from the surface to the pore). This seriously affects the contact between the flue gas and the catalyst, greatly increases the flow rate of the flue gas in the SCR reactor, and causes a large increase in the resistance of the SCR reactor, ultimately affecting the denitration effect and bringing problems such as ammonia slip, resulting in the exceeding of nitrogen oxides and ammonia at the outlet of the system. Summary of the Invention

[0004] To solve the above problems, the present invention provides a catalyst ash cleaning device and an ash cleaning method, an SCR denitration catalyst ash cleaning system and an ash cleaning method, a desulfurization and denitration system and an operation method. The SCR denitration catalyst ash cleaning system can effectively and timely remove the ash (mainly desulfurization ash) in the catalyst, ensuring good contact between the catalyst and the flue gas, and thus enabling the SCR reactor to operate normally and efficiently.

[0005] The present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a catalyst ash cleaning device, including an ash cleaning gas source and at least one ash cleaning unit;

[0007] The ash cleaning unit includes an ash cleaning gas spray pipe and a collection pipe;

[0008] The ash cleaning gas source is communicated with the ash cleaning gas spray pipe;

[0009] The ash cleaning gas spray pipe and the collection pipe are respectively arranged opposite to each other above the two surfaces of the catalyst.

[0010] In a second aspect, the present invention provides an ash cleaning method for the catalyst ash cleaning device, including the following steps:

[0011] The ash cleaning gas is sprayed on the catalyst through the ash cleaning gas spray pipe to obtain waste gas;

[0012] The collection pipe collects the waste gas and discharges it.

[0013] In a third aspect, the present invention provides an SCR denitration ash cleaning system, including the above-mentioned catalyst ash cleaning device.

[0014] In a fourth aspect, the present invention provides an ash cleaning method for the above-mentioned SCR denitration ash cleaning system, including the following steps:

[0015] The catalyst in the SCR reactor is cleaned by using the catalyst ash cleaning device.

[0016] In a fifth aspect, the present invention provides a desulfurization and denitration system, including the above-mentioned SCR denitration ash cleaning system.

[0017] In a sixth aspect, the present invention provides an operation method for the desulfurization and denitration system, including the following steps:

[0018] The catalyst in the SCR denitration ash cleaning system is cleaned by using the purified gas after denitration purification;

[0019] The temperature of the purified gas is 150°C to 400°C.

[0020] The SCR denitration ash cleaning system and ash cleaning method, desulfurization and denitration system and operation method provided by the present invention, compared with the prior art, have at least the following beneficial technical effects:

[0021] (1) The catalyst ash cleaning device provided by the present invention uses the pressure of the ash cleaning gas to clean the catalyst, and at the same time, the collection pipe sends the exhausted gas after ash cleaning out of the catalyst reaction system, thereby improving the catalytic effect of the catalyst.

[0022] (2) The ash cleaning method of the catalyst ash cleaning device provided by the present invention sprays the ash cleaning gas through the spray pipe to make the ash cleaning gas flow into the internal channel of the catalyst, takes out the dust particles staying in the internal channel, forms the exhausted gas containing dust particles, and the exhausted gas enters the collection pipe and is discharged from the catalytic system. This ash cleaning method improves the catalytic efficiency and service life of the catalyst.

[0023] (3) The SCR denitration ash cleaning system provided by the present invention includes the catalyst ash cleaning device of the present invention, which can clean the catalyst in real time and improve the catalytic efficiency of the catalyst.

[0024] (4) The ash cleaning method of the SCR denitration ash cleaning system provided by the present invention can effectively prevent the flue gas containing high-concentration particulate matter from entering the SCR reactor, and effectively clean the contaminated catalyst. It not only improves the catalytic effect and service life of the catalyst, but also prevents the unqualified flue gas from entering the atmosphere and causing air pollution.

[0025] (5) The desulfurization and denitration system provided by the present invention adopts the SCR denitration ash cleaning system provided by the present invention, which can clean the catalyst in time, improve the catalytic efficiency and service life of the catalyst, and further improve the operation stability of the desulfurization and denitration system.

[0026] (6) The operation method of the desulfurization and denitration system provided by the present invention makes full use of the purified high-temperature flue gas (150°C - 400°C) as the ash cleaning gas, reduces the operation cost of the desulfurization and denitration system (no need to externally introduce and heat the ash cleaning gas), and maintains the operation stability of the desulfurization and denitration system. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present drawings or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present drawings. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0028] Figure 1a It is a schematic structural diagram of a catalyst ash cleaning device provided in an embodiment of the invention;

[0029] Figure 1b It is a schematic structural diagram of the ash cleaning gas spray pipe provided in an embodiment of the invention;

[0030] Figure 1c Schematic diagram of the structure of the nozzle outlet provided in the invention embodiment;

[0031] Figure 1d Schematic diagram of the structure of the collection pipe provided in the invention embodiment;

[0032] Figure 1e Schematic diagram of the structure of the dust cleaning unit provided in the invention embodiment;

[0033] Figure 1f Schematic diagram of the structure of the catalyst dust cleaning device including the first on-line particulate matter detector provided in the invention embodiment;

[0034] Figure 2a Schematic diagram of the structure of the SCR reactor provided in the invention embodiment;

[0035] Figure 2b Schematic diagram of the structure of the perforated gas distribution pipe provided in the invention embodiment;

[0036] Figure 2c Schematic diagram of the structure of the catalytic unit provided in the invention embodiment;

[0037] Figure 2d Schematic diagram of the structure of the SCR denitration unit provided in the invention embodiment;

[0038] Figure 2e Schematic diagram of the structure of the SCR denitration dust cleaning system provided in the invention embodiment;

[0039] Figure 3a Schematic diagram of the structure of the desulfurization and denitration system provided in the invention embodiment;

[0040] Figure 3b Schematic diagram of the structure of the desulfurization and denitration system including a suction fan provided in the invention embodiment;

[0041] Figure 3c Schematic diagram of the structure of another desulfurization and denitration system provided in the invention embodiment;

[0042] Figure 4 Schematic diagram of the structure of the catalyst dust cleaning device provided in the invention embodiment 2.

[0043] Explanation of reference numerals:

[0044] 10 - Dust cleaning gas source;

[0045] 11 - Dust cleaning gas nozzle, 111 - Main pipeline, 112 - Branch pipe, 1121 - Nozzle outlet;

[0046] 12 - Pneumatic valve of the dust cleaning gas nozzle;

[0047] 20 - Collection pipe;

[0048] 21 - First collection port, 22 - Second collection port, 23 - Pneumatic valve of collection pipe, 24 - First on - line particulate matter detector;

[0049] 30 - Catalyst;

[0050] 40 - Booster fan;

[0051] 50 - SCR denitration unit;

[0052] 51 - SCR reactor, 511 - Electric valve of intake pipe, 512 - Intake pipe, 513 - Outer shell, 514 - Perforated air - distribution pipe, 5141 - Air holes, 515 - Uniform - distribution guide pipe, 516 - Catalytic unit, 5161 - Grid support plate, 517 - Electric valve of outlet pipe, 518 - Outlet pipe;

[0053] 52 - Second on - line particulate matter detector;

[0054] 60 - Chimney;

[0055] 70 - Pressure - stabilizing gas storage tank;

[0056] 80 - SDS desulfurization device;

[0057] 90 - Bag filter;

[0058] 100 - SCR denitration ash - cleaning system;

[0059] 201 - First ash - cleaning unit;

[0060] 202 - Second ash - cleaning unit;

[0061] 110 - Exhaust fan.

[0062] The realization, functional features and advantages of the present attached - drawing purpose will be further described with reference to the embodiments and the attached drawings. Detailed implementation manners

[0063] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be described and explained below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0064] Obviously, the following descriptions are only some examples or embodiments of the present invention, and for those of ordinary skill in the art, the present invention can also be applied to other similar scenarios without creative work. In addition, it can also be understood that although the efforts made in such a development process may be complex and lengthy, for those of ordinary skill in the art related to the contents disclosed in the present invention, some changes in design, manufacturing or production based on the technical contents disclosed in the present invention are just conventional technical means, and should not be understood as the contents disclosed in the present invention being insufficient.

[0065] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present invention and is not intended to limit the subject matter described in the claims.

[0066] If not otherwise specified, all embodiments and optional embodiments of the present invention may be combined with each other to form a new technical solution, and all technical features and optional technical features of the present invention may be combined with each other to form a new technical solution.

[0067] The term "unit catalyst" refers to a piece of catalyst such as a honeycomb (or other shapes), and multiple unit catalysts can be arranged side by side to form a layer of catalyst.

[0068] In the SDS desulfurization + bag filter + SCR denitrification process, after SDS desulfurization, it is filtered by the bag filter, and then the flue gas enters the SCR denitrification. Once the bag is damaged, more desulfurization ash will enter the SCR reactor, which is easy to block the catalyst of the SCR reactor. For example, the honeycomb denitrification catalyst generally has a large amount of desulfurization ash at 1cm to 5cm on the surface. The accumulation of desulfurization ash seriously affects the contact between the flue gas and the catalyst, and greatly increases the flow rate of the flue gas in the SCR reactor (in the SCR reactor, the flow rate of the flue gas through the catalyst is the ratio of the flue gas flow rate to the sum of the cross-sectional areas of the effective gaps of the catalyst in the SCR reactor. When part of the catalyst is blocked, the effective gap will obviously decrease, and the sum of the cross-sectional areas of the effective gaps of the catalyst in the SCR reactor will also decrease, so the flow rate of the flue gas through the catalyst will increase. The increase in flow rate will lead to an increase in resistance and ammonia escape), and cause a substantial increase in the resistance of the SCR reactor, affecting the denitrification effect and bringing about problems such as ammonia escape, and ultimately leading to excessive nitrogen oxides and ammonia at the system outlet. To address this problem, the following measures are generally taken: First, the SDS is filtered through a bag filter after desulfurization, and online real-time monitoring and alarming of particulate matter are added. Second, the SCR denitrification reactor often adopts sonic soot blowing, but from the actual operation situation, this soot blowing cleaning method is not effective for the problem of bag filter leakage after SDS.

[0069] In order to improve the catalytic denitration effect of the catalyst, an embodiment of the present invention provides a catalyst ash cleaning device and its ash cleaning method, an SCR denitration ash cleaning system and its denitration method. The catalyst ash cleaning device uses the pressure of the ash cleaning gas to clean the catalyst, and at the same time treats the exhausted gas from the ash cleaning, so as to improve the catalytic effect of the catalyst. The SCR denitration ash cleaning system is additionally provided with the ash cleaning device provided by the embodiment of the present invention, which can effectively remove the impurity particles (mainly desulfurization ash) attached to the surface of the catalyst, keep a good contact area between the flue gas and the catalyst, and thus improve the denitration efficiency of the catalyst.

[0070] The following is a detailed description of a catalyst ash cleaning device and its ash cleaning method, an SCR denitration ash cleaning system and its denitration method according to an embodiment of the present application.

[0071]

Catalyst Ash Cleaning Device

[0072] The first aspect of the embodiment of the present invention provides a catalyst ash cleaning device; as Figure 1a shown, it includes an ash cleaning gas source 10 and at least one ash cleaning unit;

[0073] The ash cleaning unit includes an ash cleaning gas spray pipe 11 and a collection pipe 20;

[0074] The ash cleaning gas source 10 is communicated with the ash cleaning gas spray pipe 11;

[0075] The ash cleaning gas spray pipe 11 and the collection pipe 20 are respectively arranged opposite to each other above the two surfaces of the catalyst 30.

[0076] The catalyst ash cleaning device provided by the embodiment of the present invention uses the pressure of the ash cleaning gas to clean the catalyst 30, and at the same time the collection pipe 20 sends out the exhausted gas from the ash cleaning from the catalyst reaction system, thereby avoiding the catalyst from being blocked by dust and improving the catalytic effect of the catalyst.

[0077] In some embodiments, the ash cleaning gas source 10 includes the purified gas with high temperature and high pressure after denitration. In this case, the high-temperature purified gas can be fully utilized as one of the ash cleaning gas sources.

[0078] Please refer to Figure 1b , in some embodiments, the ash cleaning gas spray pipe 11 includes a main pipe 111 and a plurality of parallel branch pipes 112 communicated with the main pipe 111;

[0079] The branch pipe 112 includes a plurality of parallel spray pipe outlets 1121.

[0080] Please refer to Figure 1b, in some embodiments, on the same branch pipe 112, the spacing distance m between two adjacent spray outlets is the lateral spacing between the centers of two adjacent unit catalysts. In this case, the spacing distance m is equal to the lateral spacing, such that one spray outlet faces one unit catalyst (honeycomb-shaped), facilitating ash cleaning by the ash cleaning device.

[0081] Please refer to Figure 1b , in some embodiments, the spacing distance n between adjacent branch pipes 112 is the longitudinal spacing between the centers of two adjacent unit catalysts. In this case, the spacing distance n is equal to the longitudinal spacing, such that one spray outlet faces one catalyst (honeycomb-shaped), facilitating ash cleaning by the ash cleaning device.

[0082] Please refer to Figure 1c , in some embodiments, the shape of the nozzle outlet 1121 is flared.

[0083] Please refer to Figure 1c , in some embodiments, the divergence angle α of the flared outlet is 45° to 120°. In some embodiments, the bottom area of the flared outlet is more than 1 / 2 of the cross-sectional area of the unit catalyst. In some embodiments, the distance h between the bottom surface of the flared outlet and the catalyst is 0.3 m to 0.5 m. In this case, it can be ensured that the extended surface area of the bottom surface of the flared outlet extending to the catalyst surface is not less than the cross-sectional area of the unit catalyst.

[0084] In some embodiments, the cross-sectional shape of the unit catalyst is square or circular.

[0085] In some specific embodiments, as Figure 1c shown, the cross-sectional shape of the unit catalyst is square, and the side length of the square is 0.2 m to 0.5 m.

[0086] In some specific embodiments, the cross-sectional shape of the unit catalyst is circular, and the diameter of the circle is 0.2 m to 0.5 m.

[0087] Please refer to Figure 1d , in some embodiments, the wall of the collection pipe 20 includes a number of juxtaposed first collection ports 21 and a number of juxtaposed second collection ports 22;

[0088] The plane formed by the number of juxtaposed first collection ports 21 and the number of juxtaposed second collection ports 22 is parallel to the cross-section of the catalyst 30.

[0089] In the above case, the plane formed by the number of juxtaposed first collection ports 21 and the number of juxtaposed second collection ports 22 being parallel to the cross-section of the catalyst 30 can prevent large particulate matters other than waste gas from entering the collection pipe 20 and causing accumulation blockage.

[0090] Please refer to Figure 1d, in some embodiments, the opening intervals of a plurality of juxtaposed first collection ports 21 gradually increase along the waste gas flow direction, and the magnification of the increase between two adjacent intervals is 1.2 to 1.5 times. In this case, since there is a frictional resistance loss when the waste gas flows along the pipeline of the collection pipe 20, in order to ensure that the waste gas enters the collection pipe 20 nearby, the number of openings of the first collection ports 21 is increased in the direction away from the waste gas flow direction.

[0091] Please refer to Figure 1d , in some embodiments, the opening intervals of a plurality of juxtaposed second collection ports 22 gradually increase along the waste gas flow direction, and the magnification of the increase between two adjacent intervals is 1.2 to 1.5 times. In this case, since there is a frictional resistance loss when the waste gas flows along the pipeline of the collection pipe 20, in order to ensure that the waste gas enters the collection pipe 20 nearby, the number of openings of the second collection ports 22 is increased in the direction away from the waste gas flow direction.

[0092] Please refer to Figure 1d , in some embodiments, one end of the collection pipe 20 away from the waste gas flow direction is closed. In this case, it is possible to further prevent large particles from entering the collection pipe 20 and causing accumulation blockage.

[0093] Please refer to Figure 1e , in some embodiments, the soot cleaning unit further includes a soot cleaning gas spray pipe pneumatic valve 12 and a collection pipe pneumatic valve 23;

[0094] The soot cleaning gas spray pipe pneumatic valve 12 is arranged at the front end of the soot cleaning gas spray pipe 11;

[0095] The collection pipe pneumatic valve 23 is arranged at the rear end of the collection pipe 20.

[0096] Please refer to Figure 1f , in some embodiments, the catalyst soot cleaning device further includes a first on-line particulate matter detector 24;

[0097] The first on-line particulate matter detector 24 is connected to the collection pipe 20.

[0098] In this case, the first on-line particulate matter detector 24 detects the particulate matter concentration in the waste gas in the collection pipe 20.

[0099] In some embodiments, the first on-line particulate matter detector 24 is a detector of model TL-PMM180 produced by Shenzhen Cuiyungu Technology Co., Ltd.

[0100]

Soot Cleaning Method of Catalyst Soot Cleaning Device

[0101] The second aspect of the embodiments of the present invention provides a soot cleaning method of a catalyst soot cleaning device, including the following steps:

[0102] S10. The soot cleaning gas is sprayed onto the catalyst 30 through the soot cleaning gas spray pipe 11 to obtain waste gas.

[0103] The collection pipe 20 collects the waste gas and discharges it.

[0104] For the ash cleaning method of the catalyst ash cleaning device provided by the embodiment of the present invention, the ash cleaning gas is sprayed through the spray pipe so that the ash cleaning gas flows into the internal channel of the catalyst 30, and the dust particles retained in the internal channel are carried out, forming waste gas containing dust particles, and the waste gas enters the collection pipe 20 and is discharged from the catalytic system. This ash cleaning method improves the catalytic efficiency and service life of the catalyst.

[0105] In some embodiments, in the above step S10, the ash cleaning gas includes the purified gas with high temperature and high pressure after denitrification.

[0106] In some embodiments, in the above step S10, the air pressure of the ash cleaning gas spraying is 0.4 MPa to 0.7 MPa. In this case, the impurity particles (mainly desulfurization ash) on the surface of the catalyst 30 are removed as much as possible without damaging the structure of the catalyst 30.

[0107] In some embodiments, in the above step S10, the flow rate of the ash cleaning gas entering the pores of the catalyst 30 is 8 m / s to 12 m / s.

[0108] In some embodiments, in the above step S10, the temperature of the ash cleaning gas is 150 °C to 400 °C.

[0109] In some embodiments, an ash cleaning method for a catalyst ash cleaning device is provided, and the steps are as follows:

[0110] S11. The ash cleaning gas is sprayed on the catalyst 30 through the ash cleaning gas spray pipe 11 to obtain waste gas.

[0111] S21. The collection pipe 20 collects the waste gas and discharges it.

[0112] S31. When the concentration of particulate matter in the waste gas is 10 mg / m 3 or less and lasts for more than 10 minutes, the ash cleaning is completed.

[0113] In some embodiments, in the above step S31, the first on-line particulate matter detector 24 is used to detect the concentration of particulate matter in the waste gas in real time.

[0114] In other embodiments, an ash cleaning method for a catalyst ash cleaning device is provided, and the steps are as follows:

[0115] S12. After opening the pneumatic valve 23 of the collection pipe, open the pneumatic valve 12 of the ash cleaning gas spray pipe, and the ash cleaning gas is sprayed on the catalyst 30 through the ash cleaning gas spray pipe 11 to obtain waste gas.

[0116] S22. The collection pipe 20 collects the waste gas and discharges it.

[0117] In some embodiments, in the above step S12, after the collection pipe pneumatic valve is opened for 10 s to 30 s, the dust cleaning air jet pipe pneumatic valve 12 is opened.

[0118] In some embodiments, in the above step S12, the time for the dust cleaning air to blow the catalyst 30 through the dust cleaning air jet pipe 11 (i.e., the dust cleaning time) is 30 s to 60 s.

[0119] In some other embodiments, a dust cleaning method for a catalyst dust cleaning device is provided, and the steps are as follows:

[0120] S13. After the collection pipe pneumatic valve 23 is opened, the dust cleaning air jet pipe pneumatic valve 12 is opened, and the dust cleaning air blows the catalyst 30 through the dust cleaning air jet pipe 11 to obtain waste gas.

[0121] S23. The collection pipe 20 collects the waste gas and discharges it.

[0122] S33. When the concentration of particulate matter in the waste gas is 10 mg / m 3 or less and lasts for more than 10 min, the dust cleaning is completed.

[0123]

SCR Denitration Dust Cleaning System

[0124] In a third aspect of the embodiments of the present invention, an SCR denitration dust cleaning system is provided, including the catalyst dust cleaning device provided by the embodiments of the present invention.

[0125] The SCR denitration dust cleaning system provided by the embodiments of the present invention uses the catalyst dust cleaning device provided by the embodiments of the present invention to remove the desulfurization ash retained in the catalyst 30, ensuring the catalytic efficiency of the catalyst 30.

[0126] In some embodiments, the SCR denitration dust cleaning system further includes an SCR reactor 51;

[0127] The catalyst dust cleaning device is connected to the SCR reactor 51.

[0128] In this case, the catalyst dust cleaning device is used to remove the ash (mainly desulfurization ash) retained in the catalyst 30 in the SCR reactor 51, ensuring the catalytic effect of the catalyst 30 and thus ensuring the normal operation of the SCR reactor 51.

[0129] Please refer to Figure 2a , in some embodiments, the SCR reactor 51 includes an intake pipe pneumatic valve 511, an intake pipe 512, a housing 513, a perforated air distribution pipe 514, a uniformly distributed flow guiding pipe 515, a plurality of catalytic units 516, an outlet pipe 518, and an outlet pipe electric valve 517;

[0130] The intake pipe pneumatic valve 511 is arranged on the intake pipe 512;

[0131] The air inlet pipe 512 is connected to the air inlet of the housing 513, and the air outlet pipe 518 is connected to the air outlet of the housing 513;

[0132] The air inlet, the perforated air distribution pipe 514, the uniformly distributed flow guide pipe 515, the plurality of catalytic units 516 and the air outlet are arranged in sequence;

[0133] A perforated air pipe 514, a uniformly distributed flow guide pipe 515 and a plurality of catalytic units 516 are arranged in the housing 513;

[0134] The outlet pipe electric valve 517 is arranged on the outlet pipe 518;

[0135] The cleaning units in the catalyst cleaning device correspond one to one with the catalytic units 516 .

[0136] In the above-mentioned SCR reactor 51, the flue gas is passed into the SCR reactor 51 for purification, and the cleaning gas ejected from the cleaning gas nozzle 11 of the catalyst cleaning device is ejected in a direction opposite to the flow direction of the flue gas, thereby realizing the backblowing of the catalyst 30 by the cleaning gas, i.e., backblowing cleaning; the air inlet pipe pneumatic valve 511 controls the flue gas flow in the air inlet pipe 512 into the outer casing 513, and the air outlet pipe electric valve 517 controls the discharge of the purified flue gas.

[0137] Back-blowing cleaning is a technology that uses an airflow in the opposite direction of the airflow in the device to remove accumulated dust. The air source for back-blowing cleaning is mainly nitrogen, air or other pressurized gas that meets certain pressure requirements. In the SCR reactor 51, back-blowing cleaning can reduce the operating resistance of the reactor and avoid problems such as reduced effective contact between the catalyst and the flue gas, increased flue gas flow rate in the catalyst, reduced facility denitrification efficiency, and increased ammonia escape caused by catalyst blockage.

[0138] Please refer to Figure 2b In some embodiments, a plurality of air holes 5141 are arranged on the perforated cloth air tube 514 with the air inlet as the center and extending outward;

[0139] On the same radius line, the farther away from the center direction, the smaller the distance between two adjacent air holes 5141.

[0140] In some embodiments, on the same radius line, between two adjacent spacings from the center outward, the latter spacing is 0.5 to 0.7 times the former spacing (ie, about 2 / 3 times in the disclosure).

[0141] In some embodiments, the air hole 5141 is a square hole with a side length of 6 mm to 9 mm.

[0142] In some embodiments, the total area of the plurality of air holes 5141 is more than 6 times the cross-sectional area of the air inlet pipe 512 .

[0143] In some embodiments, the uniformly distributed flow guide tube 515 is a radial flow guide tube or a porous plate flow guide tube.

[0144] In some embodiments, a plurality of catalytic units 516 are distributed layer by layer to form a multi-layer catalyst 30.

[0145] Please refer to Figure 2a , in some embodiments, the catalytic unit 516 includes a number of unit catalysts and a grid support plate 5161;

[0146] The grid support plate 5161 is disposed on the lower surface of the catalyst 30.

[0147] In this case, the grid support plate 5161 supports a number of unit catalysts to form a catalytic unit 516, so that the catalyst will not fall due to gravity or air flow.

[0148] Please refer to Figure 2c , in some embodiments, the SCR denitration soot cleaning system includes a booster fan 40 and a number of parallel SCR denitration units 50;

[0149] The SCR denitration unit 50 includes an SCR reactor 51 and a catalyst soot cleaning device;

[0150] The outlet of the SCR reactor 51 is connected to the inlet of the booster fan 40;

[0151] The outlet of the booster fan 40 is connected to the soot cleaning gas spray pipe 11 of the catalyst soot cleaning device.

[0152] In this case, the outlet of the SCR reactor 51 is connected to the inlet of the booster fan 40, and the outlet of the booster fan 40 is connected to the soot cleaning gas spray pipe 11 of the catalyst soot cleaning device, which can enable the booster fan 40 to pressurize the purified gas in the SCR reactor 51 and then send it into the catalyst soot cleaning device (as soot cleaning gas) to clean the catalyst 30 in the SCR reactor 51; the connection between the outlet of the SCR reactor 51 and the inlet of the booster fan 40 can create a negative pressure in the SCR reactor 51, so that the waste gas is discharged from the SCR reactor 51. The temperature of the purified gas is relatively high, and there is no need to heat it additionally before soot cleaning, which can save energy and improve the operation stability of the SCR denitration soot cleaning system.

[0153] In some embodiments, the outlet of the booster fan 40 is also connected to the chimney. In this case, when the SCR denitration unit does not need soot cleaning, the purified flue gas is discharged through the chimney 60.

[0154] Please refer to Figure 2d , in some embodiments, the SCR denitration unit 50 further includes a second on-line particulate matter detector 52;

[0155] The second on-line particulate matter detector 52 is located at the inlet of the SCR reactor 51.

[0156] In this case, the second on-line particulate matter detector 52 detects the concentration of particulate matter in the flue gas entering the SCR reactor 51 in real time to determine whether the catalyst needs to be cleaned, so as to clean the catalyst 30 in the SCR reactor 51 in real time and improve the catalytic efficiency of the catalyst 30.

[0157] The reason for using the second on-line particulate matter detector 52 to detect the concentration of particulate matter in the inlet flue gas of the SCR reactor 51 is that the detection of particulate matter by the total discharge port CEMS often has a lag. The reason is that the denitration reactor has an interception effect on dust. When the particulate matter index detected by the total discharge port CEMS rises significantly, a large amount of dust has been intercepted in the SCR denitration reactor, and the catalytic efficiency of the catalyst 30 will also be significantly reduced.

[0158] In some embodiments, the second on-line particulate matter detector 52 is a particulate matter detector of model TL-PMM180 produced by Shenzhen Cuiyun Valley Technology Co., Ltd.

[0159] In some embodiments, the number of SCR denitration units 50 is two or more.

[0160] Please refer to Figure 2e , in some embodiments, the SCR denitration ash cleaning system further includes a pressure stabilizing air storage tank 70;

[0161] The inlet of the pressure stabilizing air storage tank 70 is connected to the outlet of the booster fan 40;

[0162] The outlet of the pressure stabilizing air storage tank 70 is connected to the ash cleaning air spray pipe 11 of the catalyst ash cleaning device.

[0163]

Ash Cleaning Method of SCR Denitration Ash Cleaning System

[0164] The fourth aspect of the embodiments of the present invention provides an ash cleaning method for the above-mentioned SCR denitration ash cleaning system, including the following steps:

[0165] X10. Use the catalyst ash cleaning device provided by the embodiments of the present invention to clean the catalyst 30.

[0166] The ash cleaning method of the SCR denitration ash cleaning system provided by the embodiments of the present invention can effectively remove the ash (mainly desulfurization ash) retained in the catalyst 30 by using the catalyst ash cleaning device. It not only improves the catalytic effect and service life of the catalyst 30, but also prevents unqualified flue gas from entering the atmosphere through the chimney 60 and causing air pollution.

[0167] In some embodiments, an ash cleaning method for the above-mentioned SCR denitration ash cleaning system is provided, including the following steps:

[0168] X11. Use the catalyst ash cleaning device provided by the embodiments of the present invention to clean the catalyst 30 in the SCR reactor 51.

[0169] In some embodiments, in the above step X11, the catalyst soot cleaning device cleaning the catalyst 30 in the SCR reactor 51 includes the following steps:

[0170] X111. Starting from the soot cleaning unit at the outlet of the SCR reactor 51 to the soot cleaning unit at the inlet of the SCR reactor 51, sequentially clean the corresponding catalytic units 516, and the flow direction of the soot cleaning gas is opposite to the flue gas flow direction.

[0171] In the above soot cleaning step, cleaning the catalytic units 516 one by one in the order opposite to the flue gas flow direction can effectively clean the catalyst in the SCR reactor 51 in a short time, thereby improving the flue gas denitration rate.

[0172] In some embodiments, in the above step X111, the cleaning time for each catalytic unit 516 is 30 s to 60 s.

[0173] In some embodiments, in the above step X111, the air pressure of the soot cleaning gas is 0.4 MPa to 0.7 MPa.

[0174] In some embodiments, in the above step X111, the temperature of the soot cleaning gas is 150 °C to 400 °C. In this case, when the soot cleaning gas enters the SCR reactor 51, the temperature fluctuation of the catalyst in the SCR reactor 51 is low, thereby maintaining the denitration effect of the catalyst, and further enabling the normal operation of the SCR denitration soot cleaning system.

[0175] In some other embodiments, a soot cleaning method for the above SCR denitration soot cleaning system is provided, including the following steps:

[0176] X12. When the particulate matter concentration in the flue gas at the inlet of the SCR reactor 51 is greater than 10 mg / m 3 and lasts for more than 2 min, stop the flue gas from entering the bag filter, and use the catalyst soot cleaning device provided in the embodiments of the present invention to clean several catalytic units 516 in the SCR reactor 51.

[0177] In some embodiments, the second on-line particulate matter detector 52 is used to monitor the particulate matter concentration in the flue gas at the inlet of the SCR reactor 51 in real time.

[0178] In some embodiments, the second on-line particulate matter detector 52 and the catalyst soot cleaning device are PLC interlocked and controlled. When the particulate matter concentration detected by the second on-line particulate matter detector 52 in the inlet flue gas is greater than 10 mg / m 3 and lasts for more than 2 min, through interlock alarm, automatically start the catalyst soot cleaning device to clean the catalyst 30 in the SCR reactor 51.

[0179]

Desulfurization and Denitrification System

[0180] The fifth aspect of the embodiment of the present invention provides a desulfurization and denitrification system, which includes the SCR denitrification ash cleaning system 100 provided by the embodiment of the present invention.

[0181] The desulfurization and denitrification system provided by the embodiment of the present invention adopts the SCR denitrification ash cleaning system 100 provided by the embodiment of the present invention, which can timely clean the ash of the catalyst 30, improve the catalytic efficiency and service life of the catalyst 30, and further improve the operation stability of the desulfurization and denitrification system.

[0182] Please refer to Figure 3a , in some embodiments, the desulfurization and denitrification system further includes an SDS desulfurization device 80 and a bag filter 90;

[0183] The SDS desulfurization device 80, the bag filter 90 and the SCR denitrification ash cleaning system 100 are connected in sequence.

[0184] In this case, after the flue gas is desulfurized by the SDS desulfurization device 80, it enters the bag filter 90 to remove solid particles such as desulfurization ash in the flue gas, and then enters the SCR denitrification ash cleaning system 100. In the SCR denitrification ash cleaning system 100, the flue gas is purified by the SCR reactor 51 and then discharged; when too much ash accumulates in the catalyst 30 of the SCR reactor 51, it is removed by the catalyst ash cleaning device provided by the embodiment of the present invention.

[0185] In some specific embodiments, the desulfurization and denitrification system includes an SDS desulfurization device 80, a bag filter 90 and the SCR denitrification ash cleaning system 100 provided by the embodiment of the present invention. The SDS desulfurization device 80, the bag filter 90 and the SCR denitrification ash cleaning system 100 are connected in sequence;

[0186] The outlet of the collection pipe 20 in the catalyst ash cleaning device is connected to the inlet of the bag filter 90.

[0187] In this case, the connection between the outlet of the collection pipe 20 and the inlet of the bag filter 90 can enable the waste gas collected by the collection pipe 20 to enter the SCR denitrification ash cleaning system 100 again for secondary denitrification purification of the flue gas after being filtered by the bag filter 90, so that the flue gas meets the emission standards. It should be noted that both the SDS desulfurization device 80 and the bag filter 90 are commonly used devices in the art and are not modified in the embodiment of the present invention, so no special limitation is made.

[0188] Please refer to Figure 3b , in some embodiments, the desulfurization and denitrification system further includes a suction fan 110;

[0189] The suction fan 110 is arranged between the collection pipe 20 and the bag filter 90.

[0190] In this case, the exhaust fan 110 extracts the gas in the SCR reactor 51 and sends it into the bag filter 90 for further filtration of the waste gas, improving the dust cleaning rate of the catalyst dust cleaning device.

[0191] In some other embodiments, a desulfurization and denitration system is provided, as Figure 3c shown, including an SDS desulfurization device 80 and a plurality of dust cleaning and denitration units;

[0192] The dust cleaning and denitration unit includes a bag filter 90 and the SCR denitration dust cleaning system 100 provided by the embodiments of the present invention.

[0193]

Operation method of desulfurization and denitration system

[0194] The sixth aspect of the embodiments of the present invention provides an operation method of a desulfurization and denitration system, including the following steps:

[0195] Y10. Using the purified gas after denitration purification to clean the catalyst 30 in the SCR denitration dust cleaning system 100;

[0196] The temperature of the purified gas is 150°C to 400°C.

[0197] The operation method of the desulfurization and denitration system provided by the embodiments of the present invention makes full use of the purified high-temperature purified gas (150°C to 400°C) as the dust cleaning gas, reducing the operation cost of the desulfurization and denitration system (without externally introducing and heating the dust cleaning gas) and maintaining the stability of the operation of the desulfurization and denitration system.

[0198] In some embodiments, an operation method of a desulfurization and denitration system is provided, including the following steps:

[0199] Y11. After the flue gas is purified by the SDS desulfurization device 80, the bag filter 90 and the SCR reactor 51, the purified gas after purification is discharged.

[0200] Y21. When the particulate matter concentration in the flue gas at the inlet of the SCR reactor 51 is greater than 10 mg / m 3 and lasts for more than 2 minutes, stop the flue gas from entering the bag filter 90, start the catalyst dust cleaning device to clean a plurality of catalytic units 516 in the SCR reactor 51 to obtain waste gas; wherein, the dust cleaning gas is the purified gas after purification.

[0201] Y31. The waste gas is filtered by the bag filter 90 and then enters the SCR reactor 51 again.

[0202] The following is further described with specific embodiments. In the following embodiments and / or comparative examples, unless otherwise specified, the following parameters are used:

[0203] (1) The first on-line particulate matter detector 24 and the second on-line particulate matter detector 52 are both detectors of model TL-PMM180 produced by Shenzhen Cuiyungu Technology Co., Ltd.

[0204] (2) The catalyst material used is a catalyst produced by Jiangsu Xinwo Catalyst Co., Ltd. The main components in the catalyst are: the substrate is TiO2, and the active chemical components are V2O5 / MoO3.

[0205] Example 1

[0206] Example 1 provides a catalyst soot cleaning device, as Figures 1a to 1e shown, which consists of a soot cleaning gas source 10 and a soot cleaning unit:

[0207] The soot cleaning unit consists of a soot cleaning gas spray pipe 11, a collection pipe 20, a pneumatic valve 12 of the soot cleaning gas spray pipe, and a pneumatic valve 23 of the collection pipe;

[0208] The soot cleaning gas spray pipe 11 is arranged above one side of the catalyst 30;

[0209] The collection pipe 20 is arranged above the other side of the catalyst 30 and facing away from the soot cleaning gas spray pipe 11;

[0210] The soot cleaning gas spray pipe 11 is arranged above the collection pipe 20;

[0211] The pneumatic valve 12 of the soot cleaning gas spray pipe is arranged at the front end of the soot cleaning gas spray pipe;

[0212] The pneumatic valve 23 of the collection pipe is arranged at the rear end of the collection pipe 20.

[0213] Among them, the soot cleaning gas spray pipe 11 includes a main pipe 111 and a number of parallel branch pipes 112;

[0214] The parallel branch pipes 112 are communicated with the main pipe 111;

[0215] The branch pipes 112 include a number of parallel nozzle outlets 1121;

[0216] On the same branch pipe 112, the interval distance m between two adjacent spray outlets is 0.1515 m (i.e., the lateral distance between the centers of two adjacent unit catalysts).

[0217] The interval distance n between two adjacent spray outlets of adjacent branch pipes 112 is 0.1515 m (i.e., the longitudinal distance between the centers of two adjacent unit catalysts).

[0218] The shape of the nozzle outlet 1121 is trumpet-shaped, and the diffusion angle α is 60°;

[0219] The bottom area of the trumpet-shaped outlet is 1 / 2 of the cross-sectional area of the unit catalyst;

[0220] The distance h between the bottom surface of the flared outlet and the catalyst 30 is 0.5 m.

[0221] This embodiment also provides a method for cleaning the catalyst, and the steps are as follows:

[0222] S1-1. After opening the pneumatic valve of the collection pipe for 30 s, open the pneumatic valve 12 of the cleaning gas spray pipe. The cleaning gas is sprayed onto the catalyst 30 through the cleaning gas spray pipe 11 to obtain waste gas; wherein, the flow rate of the cleaning gas entering the pores of the catalyst 30 is 8 m / s.

[0223] S1-2. The collection pipe 20 collects the waste gas and discharges it.

[0224] Embodiment 2

[0225] Embodiment 2 provides a catalyst cleaning device, as Figure 4 shown, which is composed of a cleaning gas source 10, a first cleaning unit 201 and a second cleaning unit 202. The first cleaning unit 201 and the second cleaning unit 202 are in parallel;

[0226] As Figure 1e shown, both the first cleaning unit 201 and the second cleaning unit 202 are composed of a cleaning gas spray pipe 11, a collection pipe 20, a pneumatic valve 12 of the cleaning gas spray pipe and a pneumatic valve 23 of the collection pipe;

[0227] The cleaning gas spray pipe 11 is arranged above one side of the catalyst 30;

[0228] The collection pipe 20 is arranged above the other side of the catalyst 30 facing away from the cleaning gas spray pipe 11;

[0229] The cleaning gas spray pipe 11 is arranged above the collection pipe 20;

[0230] The pneumatic valve 12 of the cleaning gas spray pipe is arranged at the front end of the cleaning gas spray pipe 11;

[0231] The pneumatic valve 23 of the collection pipe is arranged at the rear end of the collection pipe 20.

[0232] This embodiment also provides a method for cleaning the catalyst, and the steps are as follows:

[0233] S2-1. In the first cleaning unit 201, after opening the pneumatic valve of the collection pipe for 10 s, open the pneumatic valve 12 of the cleaning gas spray pipe. The cleaning gas is sprayed onto the catalyst 30 through the cleaning gas spray pipe 11 to obtain waste gas; wherein, the flow rate of the cleaning gas entering the pores of the unit catalyst is 8 m / s, the temperature is 215 °C, the air pressure is 0.4 MPa, and the gas flow direction of the cleaning gas is opposite to the gas flow direction of the smoke catalyzed by the catalyst 30; the collection pipe 20 collects the waste gas and discharges it.

[0234] After the first dust cleaning unit 201 operates for 10 s, close the pneumatic valve 12 of the dust cleaning air nozzle of the first dust cleaning unit 201, and then close the pneumatic valve 23 of the collection pipe. The dust cleaning of the first dust cleaning unit 201 is completed.

[0235] S2-3. In the second dust cleaning unit 202, after opening the pneumatic valve of the collection pipe for 10 s, open the pneumatic valve 12 of the dust cleaning air nozzle. The dust cleaning air is sprayed onto the catalyst 30 through the dust cleaning air nozzle 11 to obtain waste gas. Among them, the

[0236] flow rate of the dust cleaning air entering the catalyst pore channels is 8 m / s, the temperature is 215 °C, and the air pressure is 0.4 MPa; the collection pipe 20 collects the waste gas and discharges it.

[0237] S2-4. Recursively perform the dust cleaning of the first dust cleaning unit 201 and the second dust cleaning unit 202.

[0238] Example 3

[0239] Example 3 provides a catalyst dust cleaning device, whose structure is basically the same as that of Example 2, except that:

[0240] As Figure 1f shown, the catalyst dust cleaning device further includes a first on-line particulate matter detector 24;

[0241] The first on-line particulate matter detector 24 is connected to the collection pipe 20.

[0242] This example also provides a dust cleaning method for the catalyst dust cleaning device. The steps are basically the same as those in Example 1, except that:

[0243] In step S2-4, use the first on-line particulate matter detector 24 to continuously monitor the concentration of particulate matter in the waste gas. When the concentration of particulate matter in the waste gas is 10 mg / m 3 or less and lasts for more than 10 min, the dust cleaning is completed.

[0244] Example 4

[0245] Example 4 provides an SCR denitration dust cleaning system. As Figure 2d shown, it is composed of a booster fan 40 and an SCR denitration unit 50;

[0246] The SCR denitration unit 50 is composed of a second on-line particulate matter detector 52, an SCR reactor 51, and the catalyst dust cleaning device provided in Example 2;

[0247] The outlet of the SCR reactor 51 is communicated with the inlet of the booster fan 40;

[0248] The inlet of the dust cleaning air nozzle 11 in the dust cleaning unit is connected to the outlet of the booster fan 40;

[0249] The soot cleaning air injection pipe 11 and the collection pipe 20 are arranged inside the SCR reactor 51;

[0250] The second on-line particulate matter detector 52 is connected to the inlet of the SCR reactor 51.

[0251] Among them, as Figure 2a shown, the SCR reactor 51 is composed of an inlet pipe 512, a housing 513, a perforated air distribution pipe 514, a uniformly distributed flow guiding pipe 515, two layers of catalytic units 516 (the first catalytic unit, the second catalytic unit) and an outlet pipe 518;

[0252] The inlet pipe 512 is connected to the air inlet of the housing 513, and the outlet pipe 518 is connected to the air outlet of the housing 513;

[0253] The perforated air distribution pipe 514, the uniformly distributed flow guiding pipe 515 and the two layers of catalytic units 516 are arranged in the housing 513;

[0254] And they are arranged in the order of the air inlet, the perforated air distribution pipe 514, the uniformly distributed flow guiding pipe 515, the second catalytic unit, the first catalytic unit and the air outlet.

[0255] The first soot cleaning unit 201 in the catalyst soot cleaning device is used to clean the first catalytic unit located at the air outlet, and the second soot cleaning unit 202 is used to clean the second catalytic unit.

[0256] This embodiment also provides a soot cleaning method for the SCR denitration soot cleaning system, and the steps are as follows:

[0257] S4-1. The second on-line particulate matter detector 52 continuously detects the particulate matter concentration in the flue gas at the inlet of the SCR reactor 51.

[0258] S4-2. When the particulate matter concentration in the flue gas at the inlet is 20 mg / m 3 and lasts for 2 min, stop the flue gas from entering the SCR reactor 51, and use the catalyst soot cleaning device to clean the two layers of catalytic units 516 in the SCR reactor 51. The soot cleaning air is the purified gas catalyzed by the catalyst pressurized by the booster fan 40:

[0259] S4-2-1. When the first soot cleaning unit 201 is cleaning, after opening the pneumatic valve of the collection pipe for 10 s, open the pneumatic valve of the soot cleaning air injection pipe 12. The purified gas is sprayed on the catalyst of the first catalytic unit through the soot cleaning air injection pipe 11 to obtain waste gas; among them, the flow rate of the purified gas entering the catalyst pore channels is 8 m / s, the temperature is 215 °C, and the air pressure is 0.4 MPa. The flow direction of the purified gas in the SCR reactor 51 is opposite to the flue gas flow direction; the collection pipe 20 collects the waste gas and discharges it.

[0260] After the first ash cleaning unit 201 operates for 10 s, close the pneumatic valve 12 of the ash cleaning gas spray pipe of the first ash cleaning unit 201 and then close the pneumatic valve 23 of the collection pipe, and the ash cleaning of the first ash cleaning unit 201 ends.

[0261] S4-2-3. The second ash cleaning unit 202 starts to clean ash: After opening the pneumatic valve of the collection pipe for 10 s, open the pneumatic valve 12 of the ash cleaning gas spray pipe, and the purified gas is sprayed through the ash cleaning gas spray pipe 11 to the catalyst of the second catalytic unit to obtain waste gas; among them,

[0262] The flow rate of the purified gas entering the catalyst pore channels is 8 m / s, the temperature is 215 °C, the air pressure is 0.4 MPa, and the flow direction of the purified gas in the SCR reactor 51 is opposite to the flue gas flow direction; the collection pipe 20 collects the waste gas and discharges it.

[0263] S4-4. Cycle to clean the ash of the first ash cleaning unit 201 and the second ash cleaning unit 202.

[0264] Example 5

[0265] Example 5 provides a desulfurization and denitrification system, as Figure 3b shown, which is composed of an SDS desulfurization device 80, a bag filter 90, a suction fan 110, and an SCR denitrification ash cleaning system 100 provided by Example 4;

[0266] The SDS desulfurization device 80, the bag filter 90, and the SCR denitrification ash cleaning system 100 are connected in sequence;

[0267] The outlet of the collection pipe 20 in the catalyst ash cleaning device is connected to the inlet of the bag filter 90;

[0268] The suction fan 110 is arranged between the collection pipe 20 and the bag filter 90.

[0269] This example also provides an operation method for the desulfurization and denitrification system, and the steps are as follows:

[0270] S5-1. After the flue gas is purified by the SDS desulfurization device 80, the bag filter 90, and the SCR reactor 51, the purified gas is discharged.

[0271] S5-2. When the particulate matter concentration in the flue gas at the inlet of the SCR reactor 51 is 20 mg / m 3 and lasts for more than 2 min, the treatment steps are basically the same as those in Example 4, except that: in steps S4-2-1 and S4-2-3, first turn on the suction fan 110 and then open the pneumatic valve of the collection pipe for 10 s to make the inside of the collection pipe 20 in a negative pressure state.

[0272] S5-3. The waste gas is filtered by the bag filter 90 and then enters the SCR reactor 51 again.

[0273] Comparative Example 1

[0274] Comparative Example 1 provides an SCR denitration sootblowing system, including a sonic sootblower (model DFQ-100, manufacturer: Liaoyang Jiayu Instrumentation Co., Ltd.), an SCR reactor, and an on-line particulate matter detector;

[0275] The outlet of the SCR reactor is connected to the on-line particulate matter detector;

[0276] The sonic sootblower is located outside the SCR reactor.

[0277] This comparative example also provides a sootblowing method for the SCR denitration sootblowing system, and the steps are as follows:

[0278] D10. When the particulate matter concentration in the flue gas at the outlet of the SCR reactor detected by the on-line particulate matter detector is 11 mg / m 3 , start the sonic sootblower to clean the catalyst in the SCR reactor.

[0279] Comparative Example 2

[0280] Comparative Example 2 provides an SCR denitration sootblowing system, the structure of which is basically the same as that of Example 4, except that:

[0281] The SCR denitration sootblowing system further includes a low-pressure air storage tank;

[0282] The inlet of the sootblowing air nozzle 11 is connected to the low-pressure air storage tank.

[0283] This comparative example also provides a sootblowing method for the SCR denitration sootblowing system provided in this comparative example, the steps of which are basically the same as those of Example 4, except that:

[0284] The sootblowing air is the normal-temperature compressed air in the low-pressure air storage tank; the air pressure is 0.4 MPa and the temperature is 25°C.

[0285] Comparative Example 3

[0286] Comparative Example 3 provides a sootblowing method for the SCR denitration sootblowing system provided in Comparative Example 2, the steps of which are basically the same as those of Comparative Example 3, except that:

[0287] The sootblowing air is the high-temperature compressed air in the low-pressure air storage tank; the air pressure is 0.4 MPa and the temperature is 200°C.

[0288] To verify the progressiveness of the catalyst sootblowing device and sootblowing method, SCR denitration sootblowing system and sootblowing method, and desulfurization and denitration system and operation method provided in the embodiments of the present invention, the nitrogen oxide concentration and particulate matter concentration in the flue gas after denitration in Examples 3-4 and Comparative Example 1 are detected and the denitration efficiency of the catalyst is calculated. The results are shown in Table 1 below.

[0289] Table 1

[0290]

[0291] Note: In Table 1 above, the ammonia-nitrogen molar ratio refers to the ratio of the amount of substance of ammonia added to the original flue gas before entering the SCR reactor to the amount of substance of nitrogen oxides in the original flue gas.

[0292] At least the following conclusions can be drawn from Table 1 above:

[0293] (1) Under the condition that the particulate matter concentration at the inlet of the SCR reactor, the nitrogen oxide concentration at the inlet of the SCR reactor, and the ammonia-nitrogen molar ratio are the same, the denitrification efficiency of the flue gas by the SCR denitrification ash cleaning system, the ash cleaning method, the desulfurization and denitrification system, and the operation method provided by the embodiments of the present invention remains above 84%.

[0294] (2) By comparing Examples 4-5 with Comparative Example 2, it can be seen that under the condition that the particulate matter concentration at the inlet of the SCR reactor, the nitrogen oxide concentration at the inlet of the SCR reactor, and the ammonia-nitrogen molar ratio are the same, the embodiments of the present invention use the purified gas obtained by catalytically treating the original flue gas with a catalyst as the ash cleaning gas, effectively reducing the pressure difference between the inlet and outlet of the SCR reactor, thereby improving the denitrification efficiency of the SCR reactor.

[0295] (3) By comparing Examples 4-5 with Comparative Example 1, it can be seen that under the condition that the particulate matter concentration at the inlet of the SCR reactor, the nitrogen oxide concentration at the inlet of the SCR reactor, and the ammonia-nitrogen molar ratio are the same, using the catalyst ash cleaning device and the ash cleaning method provided by the embodiments of the present invention can effectively remove the ash (mainly desulfurization ash) retained in the catalyst, significantly reduce the ammonia slip concentration, and make the ammonia concentration in the flue gas catalyzed by the SCR reactor meet the emission standards.

[0296] (4) By comparing Examples 4-5 with Comparative Example 2, it can be seen that using normal temperature compressed air as the backwashing gas source will greatly reduce the temperature of the backwashed unit, thereby reducing the denitrification efficiency of the unit and increasing the ammonia slip rate. It can be determined from this that it is obviously inappropriate to use normal temperature compressed air. However, if the compressed air is heated and then used as the backwashing gas source, it will greatly increase the energy consumption, and heating facilities need to be added. The addition of facilities will also increase the instability of the system operation.

[0297] (5)In Comparative Example 2 and Comparative Example 3, normal-temperature compressed air was used for backwashing. After the backwashing was completed, the temperature in the SCR reactor was too low and did not reach the appropriate minimum temperature of the catalyst, resulting in almost no denitrification effect. When the flue gas temperature reached above the appropriate minimum temperature, the denitrification efficiency of the catalyst gradually increased to over 80%. At an ammonia-nitrogen molar ratio of 0.85, the highest denitrification efficiency could reach about 84%. This shows that the purified gas obtained by catalyzing the raw flue gas in the embodiment of the present invention is used as the dust-removing gas, which has the same effect as high-temperature air. Using the purified gas obtained by catalysis as the dust-removing gas makes full use of the purified high-temperature flue gas (usually above 150°C), reduces the operating cost of the desulfurization and denitrification system (no need to externally introduce and heat the dust-removing gas), and maintains the stability of the operation of the desulfurization and denitrification system.

[0298] It should be noted that the present invention is not limited to the above embodiments. The above embodiments are only examples, and embodiments with the same composition and the same effect as the technical idea within the technical solution scope of the present invention are included in the technical scope of the present invention. In addition, within the scope not departing from the gist of the present invention, various modifications that those skilled in the art can think of to the embodiments, and other ways constructed by combining some constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A catalyst ash cleaning device, characterized in that, It includes a dust cleaning gas source and at least one dust cleaning unit; The dust cleaning unit includes a dust cleaning gas nozzle and a collecting pipe; The dust cleaning gas source is communicated with the dust cleaning gas nozzle; The dust cleaning gas nozzle and the collecting pipe are respectively arranged oppositely above the two surfaces of the catalyst.

2. The catalyst soot cleaning device according to claim 1, wherein The dust cleaning gas nozzle includes a main pipe and a number of parallel branch pipes communicated with the main pipe; A number of parallel nozzle outlets are included on the branch pipes; And / or, the shape of the nozzle outlet is a flared shape; And / or, the pipe wall of the collecting pipe includes a number of juxtaposed first collecting ports and a number of juxtaposed second collecting ports; The plane formed by the number of juxtaposed first collecting ports and the number of juxtaposed second collecting ports is parallel to the cross section of the catalyst.

3. The catalyst ash cleaning device according to claim 2, characterized in that, The diffusion angle α of the flared nozzle outlet is 45° to 120°; And / or, the bottom area of the flared nozzle outlet is more than 1 / 2 of the cross-sectional area of the unit catalyst; And / or, the distance between the bottom surface of the flared nozzle outlet and the opposite catalyst surface is 0.3m to 0.5m; And / or, the opening spacing of the number of juxtaposed first collecting ports gradually increases along the waste gas flow direction, and the magnification of the increase between adjacent two spacings is 1.2 times to 1.5 times; And / or, the opening spacing of the number of juxtaposed second collecting ports gradually increases along the waste gas flow direction, and the magnification of the increase between adjacent two spacings is 1.2 times to 1.5 times.

4. A method for cleaning ash of a catalyst ash cleaning device according to any one of claims 1 to 3, characterized in that, It includes the following steps: The dust cleaning gas is blown onto the catalyst through the dust cleaning gas nozzle to obtain waste gas; The collecting pipe collects the waste gas and discharges it.

5. The ash cleaning method of the catalyst ash cleaning device according to claim 4, characterized in that The air pressure of the dust cleaning gas blowing is 0.4MPa to 0.7MPa; And / or, the flow rate of the dust cleaning gas entering the catalyst pores is 8m / s to 12m / s; And / or, the temperature of the dust cleaning gas is 150°C to 400°C.

6. A SCR denitration soot cleaning system, characterized in that, It includes the catalyst dust cleaning device according to any one of claims 1 to 3.

7. The SCR denitration ash cleaning system according to claim 6, wherein, The SCR denitration dust cleaning system further includes an SCR reactor; The catalyst dust cleaning device is connected to the SCR reactor.

8. A soot cleaning method for the SCR denitration soot cleaning system according to claim 6 or 7, characterized in that, It includes the following steps: The catalyst is dust cleaned by using the catalyst dust cleaning device.

9. A desulfurization and denitrification system, characterized in that, It includes the SCR denitration dust cleaning system according to claim 6 or 7.

10. A method for operating a desulfurization and denitrification system as described in claim 9, characterized in that, It includes the following steps: The catalyst in the SCR denitration dust cleaning system is dust cleaned by using the purified gas after denitration purification; The temperature of the purified gas is 150°C to 400°C.

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