Gas chlorine dioxide generating system

Abstract

The utility model discloses a chlorine dioxide gas generating system which comprises a primary reaction device and a main reaction device, the primary reaction device comprises a primary reactor, and a reaction raw material inlet and a reaction mixed liquid outlet are formed in the primary reactor; the main reaction device comprises a main reactor, a packed bed is arranged in the main reactor, and the main reactor is provided with a hot diluent gas inlet, a residual liquid outlet and a reaction gas outlet; a reaction mixed liquid outlet of the primary reactor is positioned above the packed bed in the main reactor; the system disclosed by the utility model is sufficient in reaction, high in yield and not easy to block equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of industrial flue gas purification or space disinfection, and particularly relates to a gas chlorine dioxide generation system. Background Art

[0002] At present, the common preparation of chlorine dioxide on the market is mainly the hydrochloric acid method (R5 method), and the equipment is called a composite chlorine dioxide generator. Its main reaction formula is:

[0003] Using a composite chlorine dioxide gas generator (generating oxidation gases ClO2 and Cl2) can be used for low-temperature denitrification of industrial flue gas (about 30 - 80 °C). Compared with the traditional SCR, it has higher denitrification efficiency, lower working temperature, lower construction cost, smaller floor area, does not increase the system resistance, is flexible in layout, and is more suitable for the transformation of old plants.

[0004] In addition, ClO2 can also be widely used in the water treatment field for water disinfection, decolorization, deodorization and pre-oxidation treatment. Since chlorine dioxide gas is easily soluble in water, generally liquid chlorine dioxide is used for disinfection at present. This not only greatly reduces the application range of chlorine dioxide disinfection. For example, in some large places (such as garbage stations, airports, hospitals, stations, ports, food workshops, etc.), it is not suitable to use chlorine dioxide solution for disinfection; at the same time, the disinfection effect of liquid state is far less than that of gaseous state, and it is easy to cause waste of chlorine dioxide.

[0005] In practical applications, the relatively common hydrochloric acid method chlorine dioxide generator is made of heat-resistant and corrosion-resistant materials (such as titanium materials) as the main reactor. Under certain negative pressure and water bath constant temperature heating conditions, sodium chlorate and hydrochloric acid are added for reaction. Although this method has a simple structure, due to the design of the water bath flask type reactor, the heat transfer efficiency is low, the mass transfer of the generated chlorine dioxide is slow, and the newly added raw materials and the residual liquid after reaction cannot be separated. Therefore, the conventional hydrochloric acid method chlorine dioxide generator is limited by structure, process, cost, etc., and the output should not be too large.

[0006] Furthermore, in the reaction system of the reactor, the reaction product contains sodium chloride, and there is still unreacted dilute hydrochloric acid and water in the system. The solubility of sodium chloride in water is not large in itself, and with the presence of hydrochloric acid, it is even more difficult for sodium chloride to dissolve under such conditions. The faster the reaction, the more sodium chloride is generated. In such a specific environment, the precipitation of sodium chloride crystals becomes very easy. Therefore, the composite chlorine dioxide generator will have blockage problems irregularly, which not only has a certain impact on the performance of the generator, but even causes equipment explosion and damage, directly involving the safe operation of the equipment. Content of the Utility Model

[0007] The technical problem to be solved by the present utility model is to provide a gas chlorine dioxide generation system with sufficient reaction, high yield and not easily blocked equipment.

[0008] The technical solution adopted by the present utility model to solve its technical problem is to construct a gas chlorine dioxide generation system, including a primary reaction device and a main reaction device;

[0009] The primary reaction device includes a primary reactor. A reaction raw material inlet is provided at the upper part or top of the primary reactor, and a reaction mixture outlet is provided at the bottom or the side of the lower part.

[0010] The main reaction device includes a main reactor. A packing bed is provided in the main reactor. A hot dilution gas inlet is provided at the main reactor below the packing bed, and a residual liquid discharge outlet is provided at the bottom of the main reactor; A reaction gas outlet is provided at the main reactor above the packing bed.

[0011] The reaction mixture outlet of the primary reactor is located above the packing bed in the main reactor.

[0012] Further, in the gas chlorine dioxide generation system, preferably, a hydrochloric acid solution delivery mechanism and a sodium chlorate solution delivery mechanism are respectively connected to the top surface or upper part of the primary reactor to quantitatively inject the hydrochloric acid solution and the sodium chlorate solution into the primary reactor.

[0013] Further, in the gas chlorine dioxide generation system, preferably, the hydrochloric acid solution delivery mechanism includes a hydrochloric acid solution storage tank. The hydrochloric acid solution storage tank is connected to the primary reactor through a pipeline, and a meter is provided on the pipeline;

[0014] And / or the sodium chlorate solution delivery mechanism includes a sodium chlorate solution storage tank. The sodium chlorate solution storage tank is connected to the primary reactor through a pipeline, and a meter is provided on the pipeline.

[0015] Further, in the gas chlorine dioxide generation system, preferably, the primary reactor is of a vertical structure, and its vertical dimension is not less than twice the horizontal dimension;

[0016] The diameter of the lower reaction chamber of the primary reactor ≥ the diameter of the upper reaction chamber; or at least part of the horizontal width of the lower reaction chamber of the primary reactor ≥ the horizontal width of the upper reaction chamber.

[0017] Further, in the gas chlorine dioxide generation system, preferably, the lower part of the primary reactor is sleeved in the main reactor, and the reaction mixture outlet is located above the packing bed in the main reactor.

[0018] Further, in the gas chlorine dioxide generation system, preferably, the reaction mixture outlet of the primary reactor is a plurality of openings provided on the side wall at the bottom or middle of the primary reactor.

[0019] Further, in the gas chlorine dioxide generation system, it is preferred that the aspect ratio of the main reactor is M, where M ≥ 2.

[0020] Further, in the gas chlorine dioxide generation system, it is preferred that the aspect ratio of the main reactor is M, where 50 ≥ M ≥ 5.

[0021] Further, in the gas chlorine dioxide generation system, it is preferred that the packing in the packed bed is at least one of curved surface packing and polyhedron packing.

[0022] Further, in the gas chlorine dioxide generation system, it is preferably further provided with a thermal dilution gas generation device.

[0023] Implementing the present utility model has the following beneficial effects:

[0024] The present utility model adopts a two-stage reaction system. First, the reaction takes place in the primary reaction device, and then the unreacted reaction mixture enters the main reaction device to continue the reaction.

[0025] The primary reaction device is the primary reaction section with the highest concentration of reaction raw materials, where a relatively strong reaction will occur, generating a large amount of solids - solid NaCl crystals. At the same time, the product gas also forms a pneumatic stirring effect, which can effectively prevent the aggregation or even caking of the large amount of NaCl crystals generated in the primary reaction section, thereby effectively preventing the blockage of the packed bed in the main reaction device.

[0026] In the main reaction device, the solid-liquid mixed reaction mixture discharged from the primary reactor scatters at the top of the packed bed, and the scattered reaction mixture then flows downward through the packed bed, forming a micron-thick water film that slowly flows downward in each gap between the packings in the packed bed, greatly expanding the gas-liquid interface. At the same time, the main reactor is provided with a thermal dilution gas inlet, and the thermal dilution gas enters the main reactor from here and flows upward through the water film gaps, heating the reaction raw materials, i.e., the reaction mixture, while taking away the product gas, greatly shortening the travel distance of the product gas in the reaction mixture, significantly improving the mass transfer efficiency, accelerating the reaction speed, and thus increasing the conversion rate. And the reaction takes place in the packed bed at different heights, and the NaCl crystals are dispersed in the packed bed. As the reaction proceeds, they will completely dissolve in the residual liquid and disappear, thus ensuring the long-term safe and stable operation of the main reactor. In addition, the equipment has a simple structure, occupies a small area, and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the technical solution of the present utility model, the present utility model will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0028] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0029] Figure 2 is a schematic structural diagram of the primary reactor in an embodiment of the present utility model. Detailed implementation manners

[0030] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the detailed implementation manners of the present utility model will now be described in detail with reference to the drawings. In the following description, it should be understood that the orientation or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings and are constructed and operated in a specific orientation. This is only for the convenience of describing the technical solution and does not indicate that the indicated device or element must have a specific orientation. Therefore, it should not be construed as a limitation of the present utility model.

[0031] It should also be noted that unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", "setting", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two elements or the interaction relationship between two elements. When an element is said to be "on" or "under" another element, the element can be "directly" or "indirectly" located above the other element, or there may also be one or more intermediate elements. Terms such as "first", "second", "third", etc. are only for the convenience of describing the technical solution and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", "third", etc. can explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0032] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present utility model. However, those skilled in the art should clearly understand that the present utility model can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present utility model.

[0033] Referring to Figure 1-2 , the present utility model shows a gaseous chlorine dioxide generation system, which includes a primary reaction device 1 and a main reaction device 4.

[0034] The primary reaction device 1 includes a primary reactor 1-2. A reaction raw material inlet 1-1 is provided at the upper part or top of the primary reactor 1-2, and a reaction mixture outlet 1-3 is provided at the bottom or the side of the lower part. The main reaction device 4 includes a main reactor 4-1. A packing bed 4-5 is provided inside the main reactor 4-1. A hot dilution gas inlet 4-2 is provided on the main reactor 4-1 below the packing bed 4-5, and a residual liquid discharge port 4-4 is provided at the bottom of the main reactor 4-1. A reaction gas outlet 4-3 is provided on the main reactor 4-1 above the packing bed 4-5. The reaction mixture outlet 1-3 of the primary reactor 1-2 is located above the packing bed 4-5 inside the main reactor 4-1.

[0035] The specific sizes of the main reactor 4-1 and the primary reactor 1-2 are not limited in the present utility model and can be designed according to actual needs.

[0036] The present utility model adopts a two-stage reaction system, and a primary reactor 1-2 is provided above or at the upper part of the main reactor 4-1. The function of the primary reactor 1-2 of the present utility model is to be used for the preliminary reaction of hydrochloric acid solution and sodium chlorate solution. The primary reactor 1-2 actually conducts an incomplete reaction, that is, part of the hydrochloric acid solution and sodium chlorate solution react, and part does not react. To achieve this goal, compared with the main reactor 4-1, the size and volume of the primary reactor 1-2 are much smaller than those of the main reactor 4-1. The pressure of the product gas generated by the reaction and the addition of raw materials continuously increase the liquid pressure of the primary reactor 1-2, and discharge the reaction substances in the reaction system, so that the primary reactor 1-2 can only conduct a preliminary reaction and cannot conduct a complete reaction. The reactions occurring in the gaseous chlorine dioxide generation system include: (Main reaction), 2NaClO3 + 6HCl = 3Cl2 + 2NaCl + 3H2O (side reaction). The products of the reaction include chlorine dioxide gas, chlorine gas, solid NaCl crystals, and water. The substances discharged from the primary reactor 1-2 include the above reaction products and the unreacted hydrochloric acid solution and sodium chlorate solution, forming a reaction mixture, and the reaction mixture is discharged into the main reactor 4-1 to continue the reaction.

[0037] The main problem to be solved by the primary reactor 1-2 is to discharge a large amount of solid NaCl crystals generated by a relatively violent reaction due to the relatively high relative concentration of the reaction raw materials from the primary reactor 1-2. The principle is as follows: The raw material hydrochloric acid solution and sodium chlorate solution are directly injected into the primary reaction device 1. At this time, the concentration of the reaction raw materials is the highest, and a relatively violent reaction occurs, generating many solid NaCl crystals. These NaCl crystals will undergo gravitational sedimentation in the reaction raw materials and slowly enter the bottom of the primary reactor 1-2. As the reaction progresses, the concentration of the reaction raw materials will gradually decrease from top to bottom, and the reaction raw materials with a higher concentration in the upper part will diffuse to the bottom. The product gas floats up to form a pneumatic stirring effect, thereby greatly improving the mass transfer efficiency, accelerating the reaction rate, and increasing the conversion rate. As the reaction progresses and the liquid level of the reaction raw materials rises, the gas pressure in the reaction chamber of the primary reactor 1-2 increases, so as to press the reaction raw materials (including unreacted raw material liquids), product gas, and NaCl generated by the reaction together into the reaction mixture outlet 1-3 for discharge.

[0038] One implementation of the positional relationship between the primary reactor 1-2 and the main reactor 4-1 can be: The primary reactors 1-2 are all located above the main reactor 4-1. Only the reaction mixture outlet 1-3 of the primary reactor 1-2 is connected to the upper part or the top surface of the reaction chamber of the main reactor 4-1, and the reaction mixture outlet 1-3 is located above the packing bed 4-5 in the main reactor 4-1.

[0039] Another implementation is: The lower part of the primary reactor 1-2 is sleeved inside the main reactor 4-1, and the reaction mixture outlet 1-3 is located above the packing bed 4-5 in the main reactor 4-1. That is, there is a cavity between the packing bed 4-5 and the top surface of the main reactor 4-1, and the lower part of the primary reactor 1-2 is in this cavity.

[0040] The main structure of the primary reaction device 1 is the primary reactor 1-2. Its upper part or top is provided with a reaction raw material inlet 1-1, and the bottom side or lower side is provided with a reaction mixture outlet 1-3. The cavity of the primary reactor 1-2 where the reaction occurs is the reaction chamber. The primary reactor 1-2 is of a vertical structure, and its vertical dimension is not less than twice the horizontal dimension. "Not less than" in the present invention refers to the dimension suitable for the reaction and meeting the requirements of normal equipment, and does not mean that the vertical dimension is infinitely large. Preferably, the vertical dimension is 2-10 times the horizontal dimension. This vertically long structure enables the incoming reaction raw material hydrochloric acid solution and sodium chlorate solution to quickly mix and react in a limited horizontal space, and form a reaction gradient, that is, the concentration of the reactants gradually decreases from top to bottom. The generated solid NaCl crystals fall to the bottom of the reaction chamber of the primary reactor 1-2 and do not agglomerate under the agitation of the continuously generated gas.

[0041] In addition, further preferably, the diameter of the lower reaction chamber of the primary reactor 1-2 is ≥ the diameter of the upper reaction chamber. Specifically, the shape of the primary reactor 1-2 can be a cylindrical structure with the same diameter at the upper and lower parts, or it can be a cylindrical structure at the upper part and other shapes at the lower part, such as a hemispherical shape, a frustum of a sphere shape, or a frustum of a cone shape with a gradually increasing diameter. Or the lower part of the primary reactor 1-2 is still a cylindrical structure with a diameter larger than that of the upper part, and there is a smooth transition between the upper cylindrical structure and the lower cylindrical structure.

[0042] Another embodiment is that at least part of the lateral width of the lower reaction chamber of the primary reactor 1-2 is ≥ the lateral width of the upper reaction chamber. At least part of the lateral width means that at least part of the structure has a width in the lateral direction. For example: as Figure 2 shown, the primary reactor 1-2 is an inverted T-shaped structure, and in the left-right direction, the width of the lower reaction chamber is greater than the width of the upper reaction chamber. In addition to the above structure, it can also be a flat frustum of a cone structure with a front-back width smaller than the left-right width. Other structures that meet the requirements of the present invention are also applicable and will not be elaborated here. The present invention does not make any limitations either.

[0043] When the space of the lower reaction chamber becomes larger, the retention time of the reaction liquid increases. At the same time, under the gas and liquid pressures, the reaction mixture is more likely to be discharged. The primary reactor 1-2 can effectively prevent the agglomeration or even caking of a large amount of NaCl crystals generated in the upper part of the primary reactor 1-2, so that a large amount of NaCl crystals can be quickly discharged from the reaction mixture outlet 1-3.

[0044] The reaction mixture outlet 1-3 is provided at the bottom or the side of the lower part of the primary reactor 1-2. In the present invention, the lower side refers to the side wall at a certain distance from the bottom surface. The position not close to the bottom surface can ensure that the reaction liquid has a retention time in the reaction chamber of the primary reactor 1-2 instead of being quickly discharged. The present invention preferably sets the reaction mixture outlet 1-3 of the primary reactor 1-2 as a plurality of openings provided on the bottom or the side wall of the middle part of the primary reactor 1-2, that is, the outlet can have a smaller diameter. In this way, the primary reactor 1-2 can uniformly transport the reaction mixture to the main reactor 4-1, and the solid crystals therein are dispersed on the surface of the packing bed 4-5 to avoid blockage. In addition, the reaction liquid can be retained at the bottom of the primary reactor 1-2 to avoid too short reaction time. The number and diameter of the reaction mixture outlet 1-3 are not limited in the present invention and can be adjusted according to actual needs, on the one hand, to meet the preliminary reaction time, and on the other hand, to effectively prevent the blockage phenomenon of the primary reactor 1-2. Generally, the diameter of the reaction mixture outlet 1-3 is 2 mm - 16 mm, and the number of settings is 4 - 8. In addition to setting a plurality of reaction mixture outlets 1-3, one or two reaction mixture outlets 1-3 with a larger diameter can also be set.

[0045] Raw material injection of the primary reactor 1-2. In the present utility model, it is preferred that a hydrochloric acid solution delivery mechanism 2 and a sodium chlorate solution delivery mechanism 3 are respectively connected to the top surface or upper part of the primary reactor 1-2 to quantitatively inject the hydrochloric acid solution and the sodium chlorate solution into the primary reactor 1-2. It is preferred that the hydrochloric acid solution delivery mechanism 2 includes a hydrochloric acid solution storage tank 2-1, and the hydrochloric acid solution storage tank 2-1 is connected to the primary reactor 1-2 through a pipeline 2-3, and a meter 2-2 is provided on the pipeline 2-3; the sodium chlorate solution delivery mechanism 3 includes a sodium chlorate solution storage tank 3-1, and the sodium chlorate solution storage tank 3-1 is connected to the primary reactor 1-2 through a pipeline 3-3, and a meter 3-2 is provided on the pipeline 3-3. The power of the hydrochloric acid solution delivery mechanism 2 and the sodium chlorate solution delivery mechanism 3 is a pump, which can be various pumps suitable for the present utility model. In addition to using a pump as the power, the hydrochloric acid solution delivery mechanism 2 and the sodium chlorate solution delivery mechanism 3 can also be arranged at a position higher than the primary reactor 1-2, and the raw materials flow to the primary reactor 1-2 by their own gravity. The meter 2-2 and the meter 3-2 can use a flowmeter, or the pump can be combined with metering, and a metering pump can be used.

[0046] In addition to adopting the above structure for the raw material injection of the present utility model, other common devices capable of quantitatively delivering liquids in the prior art can also be used.

[0047] Since the hydrochloric acid solution delivery mechanism 2 and the sodium chlorate solution delivery mechanism 3 can use existing common devices, they may not be included in the scope of the structure of the present utility model and only serve as accessories to match the structure of the present utility model.

[0048] The main reactor 4-1 is the main structure of the present utility model, and the reaction mixture after the preliminary reaction needs to continue to react in its reaction chamber. The main reactor 4-1 also adopts a vertical structure. In order to react as fully as possible and improve the reaction yield, it is preferred that the aspect ratio of the main reactor 4-1 is M, M≥2, or the aspect ratio M satisfies: so that a large amount of NaCl crystal substances dissolve during the reaction and do not block the equipment. Similarly, in the present utility model, the aspect ratio refers to the size applicable to the reaction and meeting the requirements of normal equipment, and does not mean that the vertical dimension is infinitely large. It is preferred that the aspect ratio of the main reactor 4-1 is M, 50≥M≥5. That is, the vertical length of the main reactor 4-1 is much larger than the horizontal diameter. The specific aspect ratio and size design of the main reactor are determined according to actual needs, and the present utility model does not make a limitation.

[0049] After a large amount of NaCl crystals are dispersedly discharged into the main reactor 4-1, they flow downward through the packing bed 4-5 and continue to react. As the reaction proceeds, the concentration of hydrochloric acid in the reactants gradually decreases from top to bottom, and the solubility of NaCl in the reaction raw materials gradually increases, so that the final crystals will completely dissolve in the residual liquid and disappear, thus effectively avoiding the phenomenon of crystal blockage in the prior art and ensuring the long-term safe and stable operation of the main reactor.

[0050] In the main reactor 4-1, a hot dilution gas inlet 4-2 is provided below the packing bed 4-5 for inputting hot dilution gas. Preferably, the hot dilution gas is at least one of hot air and industrial hot flue gas. The industrial hot flue gas can be industrial waste gas, incineration flue gas, etc. Due to the requirements of the chlorine dioxide reaction, the temperature of the hot dilution gas is 60-80 °C.

[0051] The hot dilution gas can be generated by a hot dilution gas generating device, or the existing hot dilution gas can be transported here through a pipeline 6. The hot dilution gas generating device can be a heating device that heats air and then inputs it.

[0052] The reaction mixture forms a downwardly flowing water film slowly on the surface of the packing in the packing bed 4-5. After the hot dilution gas enters, it flows upward from the gaps in the water film on the surface of the packing. While heating the reaction mixture, it continuously takes away the product gases - chlorine dioxide and chlorine, and reduces the flow rate of the water film, promoting the reaction.

[0053] The packing bed 4-5 in the main reactor 4-1 is filled with solid packing. The packing of the present invention is required to have a relatively large specific surface area. It can be a structure composed of many sheets and has a relatively large specific surface area. Preferably, the packing in the packing bed 4-5 is at least one of curved surface packing and polyhedron packing. The curved surface packing can adopt a spherical shape with a round, elliptical or other regular or irregular shape. Preferably, it is round or elliptical, so that the gaps generated by the packing accumulation are uniform and the reaction can be better realized evenly. The polyhedron packing has a polyhedron structure in appearance, including triangular pyramids, cubes, pentahedrons, hexahedrons, or other polyhedrons.

[0054] The present invention requires that the specific surface area of the packing reaches 400 ㎡ / m 3 or more. In order to achieve a larger specific surface area, the above-mentioned curved surface packing and polyhedron packing are composed of multiple spaced flat or curved sheets and have a spherical or polyhedron shape.

[0055] Preferably, an air extraction mechanism 8 is connected to the reaction gas outlet 4-3 of the present utility model. The air extraction mechanism 8 can adopt an induced draft fan. Under the action of the induced draft fan, the product gas is continuously taken away and the water film flow rate is reduced, thereby significantly improving the mass transfer efficiency, accelerating the reaction speed, and increasing the conversion rate. The air extraction mechanism 8 can also be changed to a blast mechanism connected before the hot dilution gas inlet 4-2, or the air extraction mechanism 8 and the blast mechanism are set at the same time. The blast mechanism can adopt a blower. Under the action of the blower, hot dilution gas is blown in, so that the product gas is continuously taken away by the hot dilution gas and the water film flow rate is reduced.

[0056] In the present utility model, the gas finally discharged from the reaction gas outlet 4-3 includes: chlorine dioxide, chlorine gas, and hot dilution gas. This mixed gas can be directly used. For example, it can be sucked and transported from the pipeline 7 to the industrial waste gas treatment equipment 9 through the air extraction mechanism 8 for use.

[0057] A residual liquid discharge port 4-4 is provided at the bottom of the main reactor 4-1, and the residual liquid after the reaction is discharged therefrom. The residual liquid is discharged through the pipeline 5 and enters the residual liquid collection tank 10.

[0058] The implementation process of the present utility model:

[0059] In the primary reactor, the raw material solutions are mixed. The solid substances and the remaining raw material solutions generated by the reaction are stirred by the generated product gas to form a reaction mixture, and are driven by the generated product gas to be discharged into the main reactor; wherein, the raw material solutions include hydrochloric acid solution and sodium chlorate solution. The amounts of the hydrochloric acid solution and the sodium chlorate solution entering the primary reactor satisfy: the molar ratio of HCl to NaClO3 is (2-2.6):1. Due to the influence of side reactions, the input amount of the hydrochloric acid solution is increased. This ratio, combined with the reaction device, can significantly improve the reaction yield, and the reactant conversion rate > 90%. In the optimal case, the reactant conversion rate reaches more than 97%.

[0060] The reaction mixture scatters on the top of the packing bed 4-5 of the main reactor 4-1, and then flows downward along the packing bed 4-5 for reaction. At the same time, the packing bed 4-5 passes through the hot dilution gas from bottom to top to heat the reaction mixture, take away the product gas generated by the reaction, and slow down the downward flow rate of the reaction mixture; the reaction gas after the reaction is discharged from the reaction gas outlet above the packing bed 4-5; wherein, the reaction gas includes the product gas generated by the reaction and the hot dilution gas, the flow rate ratio of the product gas to the hot dilution gas ≤ 1:9, the temperature of the hot dilution gas is 60-80 °C, and the reaction time is 10 minutes - 30 minutes.

[0061] After the primary reaction, the reaction mixture is sprayed onto the packing bed 4-5; the reaction liquid adheres to the structural surface of the packing on the packing bed 4-5 and slowly flows downward to form a water film. At the same time, hot dilution gas is introduced at the bottom of the packing bed 4-5 and flows upward along the voids of the packing. The hot dilution gas is used to heat the water film and maintain the shape of the water film on the surface of the packing, slowing down the downward flow rate of the water film; the chlorine dioxide gas and chlorine gas generated in the water film escape from the water film into the hot dilution gas and are diluted and carried out of the packing bed 4-5 by the hot dilution gas.

[0062] When used in the field of flue gas treatment, the hot dilution gas is selected from industrial hot flue gas. While heating the water film on the surface of the packing by the industrial hot flue gas, the chlorine dioxide gas generated in the water film escapes into the industrial hot flue gas.

[0063] The ratio of the flow rate of the chlorine dioxide gas to the flow rate of the hot dilution gas is less than or equal to 1:9. Since gas ClO2 is a typical unstable substance, its volume fraction must be controlled within 10% during use, otherwise it is easy to cause an explosion in the system. Therefore, another important role of the hot dilution gas is to control the content of chlorine dioxide gas so that its ratio to the flow rate of the hot dilution gas is less than or equal to 1:9, avoiding danger in the whole system.

[0064] Example verification:

[0065] Using the gas chlorine dioxide generation device of the embodiment of the present utility model in a production line of a 300t / d waste incineration power plant in Dazhou, Sichuan, NO x content was successfully reduced to 10mg / Nm 3 The main technical performance of the gas chlorine dioxide generation device is shown in Table 1 below. Through the performance shown in this table, the reactant conversion rate of the present utility model is high, the gas chlorine dioxide yield is high, and NO can be effectively treated in the flue gas purification system. x .

[0066] Table 1 Main technical performance of a gas chlorine dioxide generation device of the present utility model

[0067] Technical indicators Performance parameters Flue gas volume <![CDATA[60000 Nm 3 / h]]> <![CDATA[NO content at the inlet of the flue gas purification system x > <![CDATA[180mg / Nm 3 > <![CDATA[NO content at the outlet of the flue gas purification system x > <![CDATA[≤10mg / Nm 3 > Chlorine dioxide gas production (kg / h) 12 Reaction time (min) 20 Reactant conversion rate 95％ Heat-carrying working medium (thermal dilution gas) Hot flue gas

[0068] It can be understood that the above embodiments only represent the preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present utility model; it should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present utility model; therefore, all equivalent transformations and modifications made to the scope of the claims of the present utility model should fall within the scope covered by the claims of the present utility model.

Claims

1. A gas chlorine dioxide generation system, characterized in that, It includes a primary reaction device and a main reaction device; The primary reaction device includes a primary reactor. A reaction raw material inlet is provided at the upper part or top of the primary reactor, and a reaction mixture outlet is provided at the bottom or the side of the lower part. The main reaction device includes a main reactor. A packing bed is provided in the main reactor. A hot dilution gas inlet is provided in the main reactor below the packing bed, and a residual liquid discharge outlet is provided at the bottom of the main reactor. A reaction gas outlet is provided in the main reactor above the packing bed. The reaction mixture outlet of the primary reactor is located above the packing bed in the main reactor.

2. The gas chlorine dioxide generation system according to claim 1, wherein The top surface or upper part of the primary reactor is respectively connected to a hydrochloric acid solution conveying mechanism and a sodium chlorate solution conveying mechanism to quantitatively inject the hydrochloric acid solution and the sodium chlorate solution into the primary reactor.

3. The gas chlorine dioxide generation system according to claim 2, characterized in that, The hydrochloric acid solution conveying mechanism includes a hydrochloric acid solution storage tank. The hydrochloric acid solution storage tank is connected to the primary reactor through a pipeline, and a meter is provided on the pipeline. And / or the sodium chlorate solution conveying mechanism includes a sodium chlorate solution storage tank. The sodium chlorate solution storage tank is connected to the primary reactor through a pipeline, and a meter is provided on the pipeline.

4. The gas chlorine dioxide generation system according to claim 1, wherein The primary reactor is of a vertical structure, and its vertical dimension is not less than twice the horizontal dimension. The diameter of the lower reaction chamber of the primary reactor ≥ the diameter of the upper reaction chamber; or at least part of the horizontal width of the lower reaction chamber of the primary reactor ≥ the horizontal width of the upper reaction chamber.

5. The gas chlorine dioxide generation system according to claim 1, characterized in that, The lower part of the primary reactor is sleeved in the main reactor, and the reaction mixture outlet is located above the packing bed in the main reactor.

6. The gas chlorine dioxide generation system according to claim 1, wherein The reaction mixture outlet of the primary reactor is a plurality of openings provided on the side wall at the bottom or middle of the primary reactor.

7. The gas chlorine dioxide generation system according to claim 1, characterized in that, The aspect ratio of the main reactor is M, and M≥2.

8. The gas chlorine dioxide generation system according to claim 7, wherein The aspect ratio of the main reactor is M, and 50≥M≥5.

9. The gas chlorine dioxide generation system according to claim 1, characterized in that, The packing in the packing bed is at least one of curved surface packing and polyhedron packing.

10. The gas chlorine dioxide generation system according to claim 1, wherein It also includes a hot dilution gas generating device.

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