Dust remover, construction method thereof and flue gas purification treatment system

Abstract

The invention discloses a dust remover, a construction method thereof and a flue gas purification treatment system. An inner partition plate system of the dust remover is divided into a first dust removal compartment, a first reaction compartment and a second dust removal compartment in a dust remover box body; a first filtering structure is arranged in the first dust removal compartment to form a first filtering unit; a reactant adding structure is arranged in the first reaction compartment to form a first reaction unit, the reactant adding structure is used for adding a reactant into the first reaction unit, and the reactant is used for being in contact reaction with a first gas-phase impurity, so that the first gas-phase impurity is separated out in the form of a second solid-phase impurity; and a second filtering structure is arranged in the second dust removal compartment to form a second filtering unit. The step-by-step treatment process of firstly removing the first solid-phase impurities (such as silica fume), then reacting the reactant with the first gas-phase impurities (such as sulfur dioxide) to generate the second solid-phase impurities, and finally removing the second solid-phase impurities is realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of flue gas purification. Specifically, embodiments of the present disclosure relate to a dust collector, a construction method of a dust collector, a flue gas purification treatment system, and an industrial silicon smelting flue gas purification treatment device. Background Art

[0002] The traditional industrial silicon smelting flue gas purification process often adopts the solution of waste heat boiler plus bag dust collector, that is, the heat of industrial silicon smelting flue gas is first recovered through the waste heat boiler to reduce the temperature of industrial silicon smelting flue gas to the designed operating temperature range of the bag dust collector, and then the cooled industrial silicon smelting flue gas is passed into the bag dust collector for dust removal and purification. Since industrial silicon smelting flue gas contains sulfur dioxide and nitrogen oxides, it is also necessary to desulfurize and / or denitrify the industrial silicon smelting flue gas. The currently more commonly used process route is: waste heat boiler → (dry) desulfurization device → bag dust collector → (low temperature) SCR denitrification reactor.

[0003] With the development of industrial silicon smelting flue gas purification technology, the applicant has proposed a series of improvement schemes. First, in the patent document with publication number CN218034491U (reference 1), an industrial silicon smelting flue gas treatment system is provided. Reference 1 (see the attached specification) Figure 5 The industrial silicon smelting flue gas treatment system (and related instructions) comprises a first waste heat boiler unit, a flue gas filtration and dust collector unit, an SCR denitrification reactor unit, a second waste heat boiler unit and a desulfurization device which are arranged in sequence, wherein the first waste heat boiler unit and the second waste heat boiler unit form an integrated heat exchange equipment, and the SCR denitrification reactor unit and the flue gas filtration and dust collector unit form a dust removal and denitrification integrated equipment.

[0004] For the industrial silicon smelting flue gas treatment system in Reference Document 1, since the desulfurization device is located at the end of the system, it is not only prone to the problem of acid condensation and equipment corrosion due to the low flue gas temperature, but the desulfurization device usually adopts wet desulfurization technology (mainly because dry desulfurization has certain requirements for flue gas temperature and setting dry desulfurization at the end of the system will cause dust emissions to exceed the standard), which increases the difficulty of handling the desulfurization products.

[0005] To solve the above problems, the applicant provided an improved industrial silicon smelting flue gas treatment system in the patent document with publication number CN218011732U (reference 2). Fig.12 The industrial silicon smelting flue gas treatment system (and related instructions) adjusts the position of the desulfurization device, arranges the desulfurization device between the first waste heat boiler unit and the flue gas filtration and dust collector unit, and requires that the sulfur in the gas phase be removed in the form of a solid phase or a carrier during desulfurization.

[0006] For the industrial silicon smelting flue gas treatment system in Reference Document 2, although the problems of acid condensation and wet desulfurization have been overcome, there is a problem that the dust intercepted by the flue gas filtration and dust collector unit contains both microsilica powder and desulfurizer and sulfur (such as sulfate) recovered by the desulfurizer, which makes it difficult to recycle the dust.

[0007] In order to further optimize the performance of the industrial silicon smelting flue gas treatment system, the applicant provided a new improvement scheme in the patent document with publication number CN221815756U (reference 3). Figure 1 The industrial silicon smelting flue gas treatment system (and related instructions) arranges the desulfurization device between the SCR denitrification reactor unit and the second waste heat boiler unit, and adds a second flue gas filter dust collector unit between the desulfurization device and the second waste heat boiler unit.

[0008] For the industrial silicon smelting flue gas treatment system in reference document three, it can not only prevent the desulfurizer and the sulfur (such as sulfate) recovered by the desulfurizer from mixing into the microsilica powder, but also recover the desulfurizer before the second waste heat boiler unit. The industrial silicon smelting flue gas treatment system in reference document three needs to add a second flue gas filter dust collector unit, resulting in an increase in the construction and use costs of the system. In addition, the process of reference document three is: first flue gas filter dust collector unit → SCR denitrification unit → desulfurization device → first flue gas filter dust collector unit. Due to the high sulfur content in the industrial silicon smelting flue gas during SCR denitrification, sulfur dioxide easily reacts with the denitrification reducing agent (usually ammonia) to form ammonium sulfate, thereby causing poisoning of the denitrification catalyst.

[0009] In summary, although the applicant has continued to improve the setting of the desulfurization device in the industrial silicon smelting flue gas treatment system, there is still room for further optimization and improvement.

[0010] It is worth noting that the currently operating industrial silicon projects still largely adopt the aforementioned traditional industrial silicon smelting flue gas purification process route. These industrial silicon projects have already made a lot of investments in bag filters. Summary of the invention

[0011] In the above context, the inventor proposes a technical idea to develop an industrial silicon smelting flue gas treatment system that can fully utilize the existing bag filter (which can be modified on the basis of the existing bag filter) and further optimize the desulfurization device setting. Based on this technical idea, the present disclosure proposes the following technical solutions. Although these technical solutions are generated based on the above technical ideas, they each focus on the specific technical problems they target and the technical effects they produce.

[0012] In the first aspect, a dust collector is provided for removing first solid-phase impurities and first gas-phase impurities in the flue gas to be treated in steps, and then outputting the treated flue gas; it comprises: a dust collector housing; an air intake structure, which is arranged in the dust collector housing and is used to input the flue gas to be treated; an exhaust structure, which is arranged in the dust collector housing and is used to output the treated flue gas; an internal partition system, which is arranged in the dust collector housing and is used to separate the required compartments in the dust collector housing; the internal partition system is used to separate the first dust removal compartment, the first reaction compartment and the second dust removal compartment in the dust collector housing; the first dust removal compartment is provided with a first filtering structure to form a first filtering unit, and the first filtering unit is used to realize a first gas-solid filtering separation and recover the first solid-phase impurities; the first A reactant adding structure is provided in the reaction compartment to form a first reaction unit, the reactant adding structure is used to add reactants to the first reaction unit, the reactants are used to contact and react with the first gas phase impurities so that the first gas phase impurities are precipitated in the form of second solid phase impurities; a second filter structure is provided in the second dust removal compartment to form a second filter unit, the second filter unit is used to achieve second gas-solid filtration separation and recover the second solid phase impurities; wherein the smoke inlet of the first filter unit is connected to the air intake structure, the smoke inlet of the first reaction unit is connected to the smoke outlet of the first filter unit, the smoke outlet of the first reaction unit is connected to the smoke inlet of the second filter unit, and the smoke outlet of the second filter unit is connected to the exhaust structure. wherein the flue gas to be treated can be industrial silicon smelting flue gas, then the first solid phase impurities can include microsilicon powder, the first gas phase impurities can include sulfur dioxide, and the reactants include desulfurizers.

[0013] In a second aspect, a flue gas purification system is provided, including a dust collector, wherein the dust collector adopts the dust collector of the first aspect mentioned above.

[0014] According to a third aspect, a method for constructing a dust collector is provided, in which a dust collector box of an existing dust collector is modified and constructed to obtain the dust collector of the first aspect.

[0015] The dust collector of the first aspect realizes a step-by-step treatment process of first removing the first solid phase impurities (such as microsilica powder), then generating the second solid phase impurities by reacting the reactant with the first gas phase impurities (such as sulfur dioxide), and finally removing the second solid phase impurities by constructing the first dust removal compartment, the first reaction compartment and the second dust removal compartment inside the dust collector housing. Moreover, this step-by-step treatment is completed in a dust collector housing, which can significantly save the construction and use costs and land occupation of the flue gas purification treatment system of the second aspect. The construction method of the dust collector of the third aspect can significantly reduce the cost of transformation.

[0016] In a fourth aspect, an industrial silicon smelting flue gas purification treatment device is provided, comprising: a first filtering unit, for receiving the flue gas to be treated output by a waste heat recovery device, performing a first gas-solid filtration separation on the flue gas to be treated and recovering a first solid-phase impurity, the waste heat recovery device being used to receive the industrial silicon furnace smelting flue gas discharged from the industrial silicon smelting furnace and performing a first waste heat recovery to output a cooled flue gas whose temperature drops to 180°C-450°C, the first cooled flue gas being used as the flue gas to be treated and containing a first solid-phase impurity and a first gas-phase impurity, the first solid-phase impurity mainly comprising microsilicon powder, and the first gas-phase impurity mainly comprising sulfur dioxide; a first reaction unit, for receiving the flue gas output by the first filtering unit after the first gas-solid filtration separation and recovering the first solid-phase impurity through the first gas-solid A reactant is added to the flue gas after filtration and separation so that the reactant contacts and reacts with the first gas phase impurities, thereby causing the first gas phase impurities to precipitate in the form of second solid phase impurities, and the reactant includes a desulfurizer; a second filtration unit is used to receive the flue gas containing the second solid phase impurities output by the first reaction unit and perform a second gas-solid filtration separation on the flue gas containing the second solid phase impurities, and an SCR denitration reaction unit is also provided after the second filtration unit. The temperature of the flue gas output by the second filtration unit after the second gas-solid filtration separation can meet the needs of the SCR denitration reaction unit, and the SCR denitration reaction unit is used to receive the flue gas output by the second filtration unit and added with the SCR denitration reducing agent, and output the denitrated flue gas after passing through the SCR denitration catalyst.

[0017] The industrial silicon smelting flue gas purification treatment device of the fourth aspect can adopt the dust collector of the first aspect. In this case, the dust collector includes a dust collector housing and an air intake structure and an exhaust structure arranged in the dust collector housing; the dust collector housing is provided with an internal partition system, and the internal partition system is separated in the dust collector housing to form a first dust removal compartment, a first reaction compartment, and a second dust removal compartment; the first dust removal compartment is provided with a first filter structure to form the first filter unit, and the first filter unit is used to achieve the first gas-solid filtration separation and recover the first solid phase impurities; the first reaction compartment is provided with a reactant addition structure to form the first reaction unit, and the reactant addition structure is used to add reactants to the first reaction unit. The reactant is used to contact and react with the first gas phase impurities so that the first gas phase impurities are precipitated in the form of second solid phase impurities; a second filter structure is provided in the second dust removal compartment to form the second filter unit, and the second filter unit is used to realize the second gas-solid filtration separation and recover the second solid phase impurities; the smoke inlet of the first filter unit is connected to the air intake structure, the smoke inlet of the first reaction unit is connected to the smoke outlet of the first filter unit, the smoke outlet of the first reaction unit is connected to the smoke inlet of the second filter unit, and the smoke outlet of the second filter unit is connected to the exhaust structure.

[0018] The industrial silicon smelting flue gas purification treatment device of the fourth aspect can realize the industrial silicon smelting flue gas purification process of waste heat recovery device → first filter unit → first reaction unit (desulfurization) → second filter unit → SCR denitrification reaction unit. In the industrial silicon smelting flue gas purification process, desulfurization is located before SCR denitrification, which significantly reduces the risk of denitrification catalyst poisoning caused by the reaction of sulfur dioxide in the industrial silicon smelting flue gas with the denitrification reductant to form ammonium sulfate.

[0019] In a fifth aspect, a dust collector is provided, comprising: a dust collector housing; an air intake structure, which is arranged in the dust collector housing and used to input the flue gas to be treated; an exhaust structure, which is arranged in the dust collector housing and used to output the treated flue gas; an internal partition system, which is arranged in the dust collector housing and used to separate the required compartments in the dust collector housing; wherein the internal partition system separates the vertical compartments arranged in a grid shape on a horizontal plane in the dust collector housing; a filtering structure is provided in the vertical compartment located in a part of the dust collector housing to form a filtering unit, and the filtering unit is used to realize gas-solid filtration separation of the flue gas to be treated, and the gas-solid filtration separation is a first treatment; a filtering function extension structure is provided in the vertical compartment located in another part of the dust collector housing to form a filtering function extension unit, and the filtering function extension unit is used to realize a second treatment of the flue gas to be treated; the flue gas to be treated becomes the treated flue gas after passing through the first treatment and the second treatment and is discharged from the dust collector housing through the exhaust structure, and the second treatment is located before or after the first treatment.

[0020] Among them, the filtering function extension structure can be a reactant adding structure, a temperature regulating structure or a gravity sedimentation structure; the reactant adding structure is used to add a reactant to the flue gas to be treated, and the reactant is used to contact and react with the target substance in the flue gas to be treated so as to remove the target substance from the flue gas to be treated.

[0021] In a sixth aspect, a flue gas purification system is provided, including a dust collector, wherein the dust collector adopts the dust collector of the fifth aspect mentioned above.

[0022] The dust collector of the fifth aspect adopts a grid-shaped vertical cabin layout scheme, and flexibly realizes multiple processing functions for the flue gas to be treated by arranging filter units and filter function extension units in different areas.

[0023] The present disclosure is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present disclosure will be partially given in the following description, partially become apparent from the following description, or be understood through practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this specification are used to assist in understanding the present disclosure. The contents provided in the drawings and their related descriptions in this specification may be used to explain the present disclosure, but shall not constitute an improper limitation on the present disclosure.

[0025] Figure 1 This is a schematic diagram of the appearance of the bag filter used in the traditional industrial silicon smelting flue gas purification process.

[0026] Figure 2 for Figure 1 A cross-sectional view of one row of vertical compartments of a bag filter is shown.

[0027] Figure 3 for Figure 1 A cross-sectional view of the transverse flue of a bag filter is shown.

[0028] Figure 4 for Figure 1 A transparent view of the transverse flue of a bag filter is shown.

[0029] Figure 5 This is a transparent view of a side surface of the transverse flue of the dust collector of the first embodiment of the present disclosure.

[0030] Figure 6 This is a transparent view of the other side of the transverse flue of the dust collector of the first embodiment of the present disclosure.

[0031] Figure 7 This is a transparent view of the entire dust collector of the first embodiment of the present disclosure.

[0032] Figure 8 This is a transparent view of the dust collector of the first embodiment of the present disclosure from another angle.

[0033] Fig. 9 for Figure 8 AA section view.

[0034] Fig.10 for Figure 8 Middle BB section view.

[0035] Fig.11 This is a schematic diagram of the principle of the dust collector of the second embodiment of the present disclosure.

[0036] Fig.12 It is a schematic diagram of the horizontal plane layout of the internal structure of the dust collector of the second embodiment of the present disclosure.

[0037] Fig.13 This is a schematic diagram of the principle of the dust collector of the third embodiment of the present disclosure.

[0038] Fig.14 This is a schematic diagram of the principle of the dust collector of the fourth embodiment of the present disclosure.

[0039] Fig.15 It is a schematic diagram of the horizontal plane layout of the internal structure of the dust collector of the fourth embodiment of the present disclosure.

[0040] Fig.16 for Fig.15 AA section view. DETAILED DESCRIPTION

[0041] The present disclosure is described clearly and completely below in conjunction with the accompanying drawings. A person of ordinary skill in the art will be able to implement the present disclosure based on these descriptions. Before describing the present disclosure in conjunction with the accompanying drawings, it should be particularly noted that:

[0042] The technical solutions and technical features provided in each section, including the following description, can be combined with each other without conflict. In addition, where possible, these technical solutions, technical features and related combinations can be assigned specific technical themes and protected by relevant patents.

[0043] The embodiments of the present disclosure involved in the following description are generally only a part of the embodiments rather than all the embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of patent protection.

[0044] Regarding the terms and units in this specification: The terms "include", "comprises", "have" and any variations thereof in this specification and the corresponding claims and related parts are intended to cover non-exclusive inclusions. In addition, other relevant terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0045] Figure 1 This is a schematic diagram of the appearance of the bag filter used in the traditional industrial silicon smelting flue gas purification process. Figure 2 for Figure 1 A cross-sectional view of one row of vertical compartments of a bag filter is shown. Figure 3 for Figure 1 A cross-sectional view of the transverse flue of a bag filter is shown. Figure 4 for Figure 1 The transparent view of the transverse flue of the bag filter is shown. Figure 1-Figure 4 As shown, the bag filter includes: a filter housing 1; an air intake structure 2, which is arranged in the filter housing 1 and used to input the flue gas to be treated; an exhaust structure 3, which is arranged in the filter housing 1 and used to output the treated flue gas; and an internal partition system 4, which is arranged in the filter housing 1 and used to separate the required compartments in the filter housing 1.

[0046] Specifically, the inner partition system 4 is divided in the dust collector box 1 to form vertical compartments 11 arranged in a grid shape on a horizontal plane (the understanding of "vertical compartments arranged in a grid shape on a horizontal plane" can be referred to the specification appendix in the patent document with publication number CN214182230U). Figure 1-3 ), each vertical cabin 11 is provided with a lower cabin (original air cabin) and an upper cabin (clean air cabin), a bag installation structure (usually a perforated plate) is provided between the lower cabin and the upper cabin, and bags 5 extending into the lower cabin are arranged and installed on the bag installation structure, and an ash hopper 13 is provided at the bottom of each vertical cabin 11, and an ash unloading device is provided at the bottom of each ash hopper 13. In addition, the dust collector housing 1 is also provided with a transverse flue 12 extending across the vertical cabins, which is used to connect the air intake structure 2 with the lower cabin of each vertical cabin 11, and to connect the exhaust structure 3 with the upper cabin of each vertical cabin 11.

[0047] Generally speaking, the dust collector housing 1 is a rectangular housing on the horizontal plane, and the inner partition system is divided in the rectangular housing to form rectangular vertical compartments 11 arranged in a grid shape on the horizontal plane. The arrangement of these vertical compartments on the horizontal plane is as follows: in the horizontal Y-axis direction (see Figure 2 ) is formed with two rows of vertical cabins, each row of vertical cabins having a horizontal X-axis direction (see Figure 2 ) are arranged on the upper side of the plurality of (here specifically 10) vertical cabins. The transverse flue 12 is arranged between the two rows of vertical cabins.

[0048] Generally speaking, the transverse flue 12 is provided with an inclined partition 14, which divides the main flue of the transverse flue 12 into an upper transverse flue and a lower transverse flue. The lower transverse flue is connected to the air inlet of the air intake structure 2, and the upper transverse flue is connected to the exhaust port of the exhaust structure 3. Figure 3 It can be seen that the inclined partition 14 makes the channel cross-sectional area of ​​the lower transverse flue gradually decrease from the air inlet of the air intake structure 2 to the exhaust port of the exhaust structure 3, and makes the channel cross-sectional area of ​​the upper transverse flue gradually increase from the air inlet of the air intake structure 2 to the exhaust port of the exhaust structure 3.

[0049] In addition, a special air guide structure is provided at the top of the upper transverse flue so that the upper cabin of each vertical cabin 11 is connected to the upper transverse flue through an independent clean air channel, and each clean air channel is controlled by a corresponding lift valve 6. In addition, a special air guide structure 21 is provided at the bottom of the lower transverse flue so that the lower cabin of each vertical cabin 11 is connected to the lower transverse flue through an independent raw air channel (the air guide structure 21 here is generally connected between the lower transverse flue and each ash hopper 13), and each raw air channel can also be controlled by a corresponding valve (not shown in the figure) to be on and off.

[0050] Patent document with publication number CN214182230U records a bag filter similar to the above-mentioned bag filter. This patent document can be used to assist in understanding the working principle of the bag filter structure. Figure 1-Figure 4 The working principle of this type of bag dust collector is: the flue gas to be treated enters the lower transverse flue from the air inlet of the air intake structure 2, and enters the lower cabin body of each vertical cabin 11 through the original air channel between the lower transverse flue and the lower cabin body of each vertical cabin 11, and is dust-removed and purified by the bag 5. The purified flue gas enters the upper cabin body of each vertical cabin 11, and then enters the upper transverse flue through the corresponding clean air channel, and finally flows out from the exhaust port of the exhaust structure 3.

[0051] There is an industrial silicon smelting flue gas purification process that uses the above-mentioned bag filter. The industrial silicon smelting flue gas purification process adopts a waste heat boiler plus a bag filter, and the specific process route is: waste heat boiler → (dry) desulfurization device → bag filter → (low temperature) SCR denitrification reactor → fan → chimney. The main problems with the industrial silicon smelting flue gas purification process are: First, the denitrification efficiency of low-temperature SCR denitrification is not high, and due to the lower limit temperature of the bag filter, medium and high temperature SCR denitrification cannot be used. Second, the dust intercepted by the bag filter contains both microsilicon powder and desulfurizer and sulfur (such as sulfate) recovered by the desulfurizer, which makes it difficult to recycle the dust.

[0052] The first embodiment of the present disclosure transforms the above-mentioned industrial silicon smelting flue gas purification process, and the transformation plan is as follows: the above-mentioned bag dust collector is transformed into a dust collector for high-temperature flue gas filtration (modified on the dust collector box of the bag dust collector), and then the industrial silicon smelting flue gas purification process is adjusted accordingly.

[0053] Figure 5 This is a transparent view of a side surface of the transverse flue of the dust collector of the first embodiment of the present disclosure. Figure 6 This is a transparent view of the other side of the transverse flue of the dust collector of the first embodiment of the present disclosure. Figure 7 This is a transparent view of the entire dust collector of the first embodiment of the present disclosure. Figure 8 This is a transparent view of the dust collector of the first embodiment of the present disclosure from another angle. Fig. 9 for Figure 8 AA section view. Fig.10 for Figure 8 The BB section view. Figure 5-Figure 10 The specific transformation plan is introduced as follows.

[0054] First, the transverse flue 12 is modified. Figure 5-Figure 6As shown, on the basis of the existing transverse flue 12 structure, firstly, a longitudinal partition 15 is added to the transverse flue 12, and the longitudinal partition 15 and the oblique partition 14 are cross-arranged, and together divide the main flue of the transverse flue 12 into four flues, namely, the first air intake flue 121, the first exhaust flue 122, the second air intake flue 123 and the second exhaust flue 124; then, a first baffle 16 is arranged in the air intake port of the air intake structure 2 to separate the second air intake flue 123 from the air intake port of the air intake structure 2; in addition, a second baffle 17 is arranged in the exhaust port of the exhaust structure 3 to separate the first exhaust flue 122 from the exhaust port of the exhaust structure 3; finally, a third baffle 18 is inserted into the first air intake flue 121 near the exhaust port of the exhaust structure 3 to close the end of the first exhaust flue 122, and an opening 19 is reserved in the area on the longitudinal partition 15 below the oblique partition 14 and between the third baffle 18 and the exhaust port of the exhaust structure 3. Note that the position of the third baffle 18 should ensure that the untreated flue gas entering the first air inlet duct 121 from the air inlet port of the air inlet structure 2 cannot directly enter the last two vertical chambers 11 (serving as the first reaction compartment 11a) in the column of vertical chambers 11 on the left side of the first air inlet duct 121.

[0055] Secondly, the last two vertical chambers 11 (as the first reaction compartments 11a) of a row of vertical chambers 11 on the left side of the first air inlet duct 121 / first exhaust duct 122 are modified. Figure 7-Figure 8 As shown, all the bags in the last two vertical compartments 11 (serving as the first reaction compartment 11a) of a row of vertical compartments 11 on the left side of the first air inlet flue 121 / first exhaust flue 122 are taken out, and the bag mounting structure (orifice plate) is also disassembled, so that the two vertical compartments 11 form a cavity. In addition, a reactant adding structure is installed in the cavity, and the reactant adding structure is used to add reactants to the cavity, and the reactants are used to contact and react with the first gas phase impurities so that the first gas phase impurities are precipitated in the form of second solid phase impurities. When the flue gas to be treated is industrial silicon smelting flue gas, the first gas phase impurities mainly include sulfur dioxide, and the reactants include desulfurizers. The reactant adding structure may include a reactant adding tube ( Figure 5-Figure 10 Finally, ventilation holes 20 (“louver” type ventilation holes are used here to improve the uniformity of airflow) are provided on the side walls of the last two vertical chambers 11 (as the first reaction compartments 11a) of a row of vertical chambers 11 on the left side of the first air inlet duct 121 / first exhaust duct 122, which are separated from the first exhaust duct 122.

[0056] Finally, all the cloth bags in the remaining vertical compartments 11 are replaced with metal filter elements or ceramic filter elements. In the first embodiment of the present disclosure, a metal membrane filter element developed and manufactured by the applicant is specifically used. Since the length of the metal membrane filter element is currently shorter than that of the cloth bag, the height of the cloth bag mounting structure (orifice plate) can be moved down a certain distance based on the current basis, depending on the length specification of the selected metal membrane filter element.

[0057] Through the above transformation, the dust collector of the first embodiment of the present disclosure is obtained. It includes: a dust collector housing 1; an air intake structure 2, which is arranged in the dust collector housing 1 and is used to input the flue gas to be treated; an exhaust structure 3, which is arranged in the dust collector housing 1 and is used to output the treated flue gas; an internal partition system 4, which is arranged in the dust collector housing 1 and is used to separate the required compartments in the dust collector housing 1; wherein, the internal partition system 4 separates and forms a first dust removal compartment, a first reaction compartment 11a and a second dust removal compartment in the dust collector housing 1; a first filter structure is provided in the first dust removal compartment to form a first filter unit, and the first filter unit is used to realize a first gas-solid filtration separation and recover the first solid phase impurities; a reactant addition structure is provided in the first reaction compartment to form a first reaction unit element, the reactant adding structure is used to add reactants to the first reaction unit, the reactants are used to contact and react with the first gas phase impurities so that the first gas phase impurities are precipitated in the form of second solid phase impurities; the second dust removal compartment is provided with a second filter structure to form a second filter unit, the second filter unit is used to achieve a second gas-solid filtration separation and recover the second solid phase impurities; wherein, the smoke inlet of the first filter unit is connected to the air intake structure 2, the smoke inlet of the first reaction unit is connected to the smoke outlet of the first filter unit, the smoke outlet of the first reaction unit is connected to the smoke inlet of the second filter unit, and the smoke outlet of the second filter unit is connected to the exhaust structure 3.

[0058] Specifically, the flue gas to be treated is industrial silicon smelting flue gas, the first solid phase impurities mainly include microsilicon powder, the first gas phase impurities mainly include sulfur dioxide, and the reactant includes a desulfurizer.

[0059] More specifically, the inner partition system 4 is divided in the dust collector housing 1 to form vertical cabins 11 arranged in a grid shape on a horizontal plane, and the dust collector housing 1 is provided with a transverse flue 12 extending across the vertical cabins 11, and the transverse flue includes a first air intake flue 121, a first exhaust flue 122, a second air intake flue 123 and a second exhaust flue 124; the multiple vertical cabins located in the first area of ​​the dust collector housing 1 (i.e., the other vertical cabins 11 in a row of vertical cabins 11 on the left side of the first air intake flue 121 / the first exhaust flue 122 except the last two vertical cabins 11) respectively constitute independent first dust collectors. The plurality of vertical compartments located in the second area of ​​the dust collector housing 1 (i.e., a row of vertical compartments 11 on the right side of the second air inlet flue 123 / the second exhaust flue 124) respectively constitute independent second dust removal compartments, and the first reaction compartment 11a (i.e., the last two vertical compartments 11 in a row of vertical compartments 11 on the left side of the first air inlet flue 121 / the first exhaust flue 122) are located in the third area of ​​the dust collector housing 1; each first dust removal compartment is provided with a first lower compartment and a first upper compartment, and a first filter element mounting structure is provided between the first lower compartment and the first upper compartment, and the first filter element mounting structure is used to install a filter element extending into the first A first filter element in the lower cabin (specifically a metal membrane filter element) is used to retain the first solid-phase impurities in the first lower cabin; each second dust removal compartment is provided with a second lower cabin and a second upper cabin, a second filter element mounting structure is provided between the second lower cabin and the second upper cabin, the second filter element mounting structure is used to install a second filter element (specifically a metal membrane filter element) extending into the second lower cabin, the second filter element is used to retain the second solid-phase impurities in the second lower cabin; the first air inlet flue 121 is simultaneously connected to the smoke inlet of each first lower cabin, the first The air inlet end of an air inlet duct 121 constitutes the air inlet port of the air inlet structure 2, the first exhaust duct 122 is simultaneously connected to the smoke outlet of each first upper cabin body, and the exhaust end of the first exhaust duct 122 is connected to the smoke inlet of the first reaction unit (connected through the vent 20); the second air inlet duct 123 is simultaneously connected to the smoke inlet of each second lower cabin body, the air inlet end of the second air inlet duct 123 is connected to the smoke outlet of the first reaction unit, the second exhaust duct 124 is simultaneously connected to the smoke outlet of each second upper cabin body, and the exhaust end of the second exhaust duct 124 constitutes the exhaust port of the exhaust structure 3.

[0060] More specifically, the dust collector box 1 is a rectangular box on the horizontal plane, and the internal partition system 4 divides the rectangular box into rectangular vertical compartments arranged in a grid shape on the horizontal plane; the first area constitutes the first side of the rectangular box, the second area constitutes the second side of the rectangular box, and the first side and the second side are opposite sides; the third area constitutes the third side of the rectangular box, and the third side is an adjacent side to the first side.

[0061] More specifically, the vertical cabins located in the first area and the vertical cabins located in the second area are arranged in the horizontal plane as follows: two rows of vertical cabins are formed in the horizontal Y-axis direction, and each row of vertical cabins has a plurality of vertical cabins arranged in the horizontal X-axis direction; the main flue of the transverse flue 12 formed by the first air intake flue, the first exhaust flue, the second air intake flue and the second exhaust flue is arranged between the two rows of vertical cabins; the first area and the second area are distributed on the left and right sides of the main flue.

[0062] like Figure 9-10 As shown (the arrows in the figure indicate the direction of flue gas flow), the working principle of the dust collector of the first embodiment of the present invention is as follows: the flue gas to be treated (industrial silicon smelting flue gas) first enters the first air inlet duct 121, and then enters each first dust removal compartment (first filter unit) through the corresponding air guide structure 21, and then passes through the first filter element to perform the first gas-solid filtration separation and recover the first solid phase impurities (microsilicon powder), and the third baffle 18 prevents the flue gas to be treated in the first air inlet duct 121 of the air inlet structure from directly entering the last two vertical compartments 11 (serving as the first reaction compartment 11a) in the column of vertical compartments 11 on the left side of the first air inlet duct 121. The flue gas after the first gas-solid filtration and separation enters the first exhaust flue 122. Since a second baffle 17 is provided in the exhaust port of the exhaust structure 3, the first exhaust flue 122 is separated from the exhaust port of the exhaust structure 3. At the same time, the lifting valve corresponding to the first reaction compartment 11a is also closed. At this time, the flue gas in the first exhaust flue 122 can only enter the first reaction compartment 11a (first reaction unit) from the air vent 20 opened on the side wall separating the first reaction compartment 11a from the first exhaust flue 122. The first reaction unit receives the flue gas after the first gas-solid filtration and separation output by the first filtering unit, and adds a reactant (including a desulfurizer) to the flue gas after the first gas-solid filtration and separation, so that the reactant contacts and reacts with sulfur dioxide, thereby causing the sulfur dioxide to precipitate in the form of a second solid phase impurity (if the desulfurizer is a calcium-based desulfurizer, the second solid phase impurity is calcium sulfate). The flue gas containing the second solid impurities then enters the second air inlet duct 123 from the air guide structure 21 of the first reaction compartment 11a, and then undergoes second gas-solid filtration and separation in each second dust removal compartment (second filter unit). Finally, the treated flue gas is discharged from the exhaust port of the exhaust structure 3.

[0063] An industrial silicon smelting flue gas purification process uses the dust collector of Example 1. The industrial silicon smelting flue gas purification process specifically adopts the process route: first waste heat boiler unit (the temperature of the flue gas to be treated is 300°C-450°C) → dust collector → SCR denitration reactor unit → second waste heat boiler unit → fan → chimney.

[0064] The dust collector of the first embodiment of the present disclosure can not only recycle microsilica powder separately, but also, since all the bags are replaced with metal membrane filter elements, the temperature of the treated flue gas can be significantly increased. In this way, the subsequent SCR denitrification reactor unit can achieve medium and high temperature SCR denitrification, thereby improving the denitrification efficiency.

[0065] It should be pointed out that the dust collector of the first embodiment of the present disclosure is a two-stage dust collector connected in series based on the previous bag dust collector, which will inevitably lead to an increase in the filtration wind speed of each stage of the dust collector (the two-stage dust collector connected in series leads to an increase in the air flow rate passing through the unit area). The metal filter element or the ceramic filter element is just suitable for higher filtration wind speeds (the high structural strength can withstand a larger filtration wind speed, and can still maintain a stable filtration efficiency at high wind speeds), which just allows the advantages of the metal filter element or the ceramic filter element to be brought into play. When the dust collector of the first embodiment of the present disclosure is in operation, the filtration wind speeds of the first filter unit and the second filter unit can usually be set to 0.8m / min-1.5m / min.

[0066] Fig.11 This is a schematic diagram of the principle of the dust collector of the second embodiment of the present disclosure. Fig.12 FIG. 2 is a schematic diagram of the horizontal layout of the internal structure of the dust collector of the second embodiment of the present disclosure. Figure 11-Figure 12 As shown, the dust collector of the second embodiment of the present disclosure can still be modified based on the existing bag dust collector, but the internal structure of the dust collector is different from the internal structure of the dust collector of the first embodiment.

[0067] The specific modification scheme for modifying the above-mentioned bag filter into the dust collector of the second embodiment of the present disclosure is introduced as follows. First, the transverse flue 12 is modified. The original inclined partition 14 is removed, and two shorter inclined partitions are installed in the front section and the rear section of the transverse flue 12, respectively, and the two ends of the middle section of the transverse flue 12 between the front section and the rear section are blocked with corresponding baffles, respectively, so that the main flue of the transverse flue 12 is divided into four flues, namely the first air intake flue 121, the first exhaust flue 122, the second air intake flue 123 and the second exhaust flue 124, the first exhaust flue 122 is located above the first air intake flue 121 (with an independent inclined partition between them), and the second exhaust flue 124 is located above the second air intake flue 123 (with an independent inclined partition between them as well). Secondly, all the bags in the vertical compartments 11 on both sides of the middle section are taken out, and the bag installation structure (orifice plate) is also disassembled, so that these vertical compartments 11 form cavities. In addition, these cavities are connected to form a first reaction compartment, and then a reactant addition structure is installed in the first reaction compartment, and an internal guide structure is set in the first reaction compartment to form a tortuous flow channel. Finally, all the bags in the remaining vertical compartments 11 are replaced with metal membrane filter elements.

[0068] The dust collector of the second embodiment of the present disclosure thus formed includes: a dust collector housing 1; an air intake structure 2, which is arranged in the dust collector housing 1 and is used to input the flue gas to be treated; an exhaust structure 3, which is arranged in the dust collector housing 1 and is used to output the treated flue gas; an internal partition system 4, which is arranged in the dust collector housing 1 and is used to separate the required compartments in the dust collector housing 1; wherein the internal partition system 4 separates and forms a first dust removal compartment, a first reaction compartment 11a and a second dust removal compartment in the dust collector housing 1; a first filtering structure is provided in the first dust removal compartment to form a first filtering unit, and the first filtering unit is used to realize a first gas-solid filtering separation and recover the first solid phase impurities; a reactant addition structure is provided in the first reaction compartment. The first reaction unit is formed by a structure, and the reactant adding structure is used to add a reactant to the first reaction unit, and the reactant is used to contact and react with the first gas phase impurities so that the first gas phase impurities are precipitated in the form of second solid phase impurities; the second dust removal compartment is provided with a second filtering structure to form a second filtering unit, and the second filtering unit is used to realize a second gas-solid filtering separation and recover the second solid phase impurities; wherein, the smoke inlet of the first filtering unit is connected to the air intake structure 2, the smoke inlet of the first reaction unit is connected to the smoke outlet of the first filtering unit, the smoke outlet of the first reaction unit is connected to the smoke inlet of the second filtering unit, and the smoke outlet of the second filtering unit is connected to the exhaust structure 3.

[0069] Specifically, the flue gas to be treated is industrial silicon smelting flue gas, the first solid phase impurities mainly include microsilicon powder, the first gas phase impurities mainly include sulfur dioxide, and the reactant includes a desulfurizer.

[0070] More specifically, the inner partition system 4 is divided in the dust collector housing 1 to form vertical compartments 11 arranged in a grid shape on a horizontal plane, and the dust collector housing 1 is provided with a transverse flue 12 extending across the vertical compartments 11, and the transverse flue 12 comprises a first air intake flue 121, a first exhaust flue 122, a second air intake flue 123 and a second exhaust flue 124, the first exhaust flue 122 is located above the first air intake flue 121 (an independent oblique partition is provided between them), and the second exhaust flue 124 is located above the second air intake flue 123 (an independent oblique partition is also provided between them); the first exhaust flue 122 located in the dust collector housing 1 The plurality of vertical chambers in the first area (i.e., the vertical chambers 11 on both sides of the first air inlet duct 121 and the first exhaust duct 122) respectively constitute independent first dust removal compartments, and the plurality of vertical chambers in the second area of ​​the dust collector housing 1 (i.e., the vertical chambers 11 on both sides of the second air inlet duct 123 and the second exhaust duct 124) respectively constitute independent second dust removal compartments, and the first reaction compartment 11a is located in the third area of ​​the dust collector housing 1; each first dust removal compartment is provided with a first lower compartment and a first upper compartment, and a first filter element mounting structure is provided between the first lower compartment and the first upper compartment, and the first filter element mounting structure is used to install a filter element extending into the first filter element. The first filter element (specifically a metal membrane filter element) in the first lower cabin is used to retain the first solid-phase impurities in the first lower cabin; each second dust removal compartment is provided with a second lower cabin and a second upper cabin, a second filter element mounting structure is provided between the second lower cabin and the second upper cabin, the second filter element mounting structure is used to install a second filter element (specifically a metal membrane filter element) extending into the second lower cabin, the second filter element is used to retain the second solid-phase impurities in the second lower cabin; the first air inlet flue 121 is simultaneously connected to the smoke inlet of each first lower cabin, The air inlet end of the first air inlet duct 121 constitutes the air inlet port of the air inlet structure 2, the first exhaust duct 122 is simultaneously connected to the smoke outlet of each first upper cabin body, and the exhaust end of the first exhaust duct 122 is connected to the smoke inlet of the first reaction unit (connected through the vent 20); the second air inlet duct 123 is simultaneously connected to the smoke inlet of each second lower cabin body, the air inlet end of the second air inlet duct 123 is connected to the smoke outlet of the first reaction unit, the second exhaust duct 124 is simultaneously connected to the smoke outlet of each second upper cabin body, and the exhaust end of the second exhaust duct 124 constitutes the exhaust port of the exhaust structure 3.

[0071] More specifically, the dust collector box 1 is a rectangular box on the horizontal plane, and the internal partition system 4 divides the rectangular box into rectangular vertical compartments arranged in a grid shape on the horizontal plane; the first area constitutes the first side of the rectangular box, and the second area constitutes the second side of the rectangular box, and the first side and the second side are opposite sides; the third area is located between the first area and the second area.

[0072] More specifically, the vertical cabins located in the first area and the vertical cabins located in the second area are arranged in the horizontal plane as follows: two rows of vertical cabins are formed in the horizontal Y-axis direction, and each row of vertical cabins has a plurality of vertical cabins arranged in the horizontal X-axis direction; the main duct of the transverse flue 12 formed by the first air intake duct, the first exhaust smoke duct, the second air intake duct and the second exhaust smoke duct is arranged between the two rows of vertical cabins; the first area and the second area are distributed along the front-to-back direction of the entire transverse flue 12.

[0073] The dust collector of the second embodiment maintains the basic advantages of the first embodiment, and at the same time improves the rationality of the flue gas flow through the improvement of the structural layout.

[0074] Fig.13 Schematic diagram of the dust collector of the third embodiment of the present disclosure. Fig.13 As shown, the dust collector of the third embodiment of the present disclosure is based on the dust collector of the second embodiment, and an SCR denitration reaction unit is also assembled on the dust collector, and the SCR denitration reaction unit is arranged between the flue gas outlet of the second filter unit and the exhaust structure. Specifically, the SCR denitration reaction unit is arranged in the second exhaust flue 124. The SCR denitration reaction unit is used to receive the flue gas output by the second filter unit and added with the SCR denitration reducing agent and output the treated flue gas after denitration after passing through the SCR denitration catalyst.

[0075] The dust collector of the third embodiment is based on the second embodiment, and the SCR denitration reaction unit is directly integrated into the dust collector (arranged in the second exhaust flue), thereby improving the system integration.

[0076] Fig.14 This is a schematic diagram of the principle of the dust collector of the fourth embodiment of the present disclosure. Fig.15 It is a schematic diagram of the horizontal plane layout of the internal structure of the dust collector of the fourth embodiment of the present disclosure. Fig.16 for Fig.15 AA section view. Figure 14-16 As shown, the dust collector of the fourth embodiment of the present disclosure is based on the dust collector of the second embodiment, and reduces the occupation of the first reaction compartment 11a to the overall length of the dust collector, and through the design of the relevant partition, the first reaction compartment 11a has an annular flow channel ( Figure 14-15The reactant addition pipe is inserted into the inlet of the annular flow channel from top to bottom), the flue gas inlet of the annular flow channel is connected to the exhaust end of the first exhaust flue, and the flue gas outlet of the annular flow channel is connected to the intake end of the second intake flue ( Fig.16 The wavy line in the middle indicates the flow direction of the flue gas in the annular flow channel). In addition, in order to reduce costs, the second dust removal compartment continues to use cloth bags.

[0077] By reducing the occupation of the first reaction compartment 11a to the overall length of the dust collector, the space utilization of the first reaction compartment is optimized, thereby providing conditions for continuing to use the bags.

[0078] An industrial silicon smelting flue gas purification process uses the dust collector of Example 4. The industrial silicon smelting flue gas purification process specifically adopts the process route: first waste heat boiler unit (the temperature of the flue gas to be treated is 180°C) → dust collector → (low temperature) SCR denitration reactor unit → fan → chimney.

[0079] The above is a description of the relevant contents of the present disclosure. A person skilled in the art will be able to implement the present disclosure based on these descriptions. Based on the above contents of this specification, all other embodiments obtained by a person skilled in the art without making any creative work shall fall within the scope of patent protection.

Claims

1. A dust collector, which is used to remove first solid phase impurities and first gas phase impurities in the flue gas to be treated in steps, and then output the treated flue gas; It includes: Dust collector box; An air intake structure, arranged in the dust collector housing and used for inputting the flue gas to be processed; An exhaust structure, disposed in the dust collector housing and used to output the processed flue gas; An internal partition system, arranged in the dust collector box and used to separate the dust collector box into required compartments; Features: The inner partition system is separated in the dust collector housing to form a first dust removal compartment, a first reaction compartment and a second dust removal compartment; A first filter structure is provided in the first dust removal compartment to form a first filter unit, and the first filter unit is used to achieve first gas-solid filtration separation and recover the first solid impurities; The first reaction compartment is provided with a reactant adding structure to form a first reaction unit, the reactant adding structure is used to add a reactant to the first reaction unit, the reactant is used to contact and react with the first gas phase impurity so that the first gas phase impurity is precipitated in the form of a second solid phase impurity; The second dust removal compartment is provided with a second filter structure to form a second filter unit, and the second filter unit is used to achieve second gas-solid filtration separation and recover the second solid impurities; Among them, the smoke inlet of the first filter unit is connected to the air intake structure, the smoke inlet of the first reaction unit is connected to the smoke outlet of the first filter unit, the smoke outlet of the first reaction unit is connected to the smoke inlet of the second filter unit, and the smoke outlet of the second filter unit is connected to the exhaust structure.

2. The dust collector according to claim 1, characterized in that: The inner partition system is used to separate the vertical compartments arranged in a grid shape on the horizontal plane in the dust collector box. The dust collector box is provided with a transverse flue that extends across and connects the vertical compartments. The transverse flue includes a first air intake flue, a first exhaust flue, a second air intake flue and a second exhaust flue. The plurality of vertical chambers located in the first area of ​​the dust collector housing respectively constitute independent first dust removal compartments, the plurality of vertical chambers located in the second area of ​​the dust collector housing respectively constitute independent second dust removal compartments, and the first reaction compartment is located in the third area of ​​the dust collector housing; Each first dust removal compartment is provided with a first lower compartment and a first upper compartment, a first filter element mounting structure is provided between the first lower compartment and the first upper compartment, the first filter element mounting structure is used to mount a first filter element extending into the first lower compartment, the first filter element is used to retain the first solid phase impurities in the first lower compartment; Each second dust removal compartment is provided with a second lower compartment and a second upper compartment, a second filter element mounting structure is provided between the second lower compartment and the second upper compartment, the second filter element mounting structure is used to mount a second filter element extending into the second lower compartment, and the second filter element is used to retain the second solid phase impurities in the second lower compartment; The first air intake duct is connected to the smoke inlet of each first lower cabin body at the same time, the air intake end of the first air intake duct constitutes the air intake port of the air intake structure, the first exhaust duct is connected to the smoke outlet of each first upper cabin body at the same time, and the exhaust end of the first exhaust duct is connected to the smoke inlet of the first reaction unit; The second air inlet duct is simultaneously connected to the smoke inlet of each second lower compartment, the air inlet end of the second air inlet duct is connected to the smoke outlet of the first reaction unit, the second exhaust duct is simultaneously connected to the smoke outlet of each second upper compartment, and the exhaust end of the second exhaust duct constitutes the exhaust port of the exhaust structure.

3. The dust collector according to claim 2, characterized in that: The dust collector box is a rectangular box on the horizontal plane, and the inner partition system is divided in the rectangular box to form rectangular vertical cabins arranged in a grid shape on the horizontal plane; The first area constitutes a first side of the rectangular box, the second area constitutes a second side of the rectangular box, and the first side and the second side are opposite sides; The third area is located between the first area and the second area or constitutes a third side of the rectangular box, and the third side is an adjacent side of the first side and / or the second side.

4. The dust collector according to claim 3, characterized in that: The vertical cabins located in the first area and the vertical cabins located in the second area are arranged in the horizontal plane in the following manner: two rows of vertical cabins are formed in the horizontal Y-axis direction, and each row of vertical cabins has a plurality of vertical cabins arranged in the horizontal X-axis direction; The main flue of the transverse flue formed by the first air intake flue, the first exhaust flue, the second air intake flue and the second exhaust flue is arranged between the two rows of vertical cabins; When the third area is located between the first area and the second area, the first area and the second area are distributed along the front-to-back direction of the main flue; When the third area constitutes the third side of the rectangular box, the first area and the second area are distributed on the left and right sides of the main flue.

5. The dust collector according to claim 4, characterized in that: The first reaction compartment has an annular flow channel surrounding the main flue, a flue gas inlet of the annular flow channel is communicated with the exhaust end of the first exhaust flue, and a flue gas outlet of the annular flow channel is communicated with the intake end of the second intake flue.

6. The dust collector according to any one of claims 2 to 5, characterized in that: An ash hopper is provided at the bottom of each vertical cabin, and an ash unloading device is provided at the bottom of each ash hopper.

7. The dust collector according to any one of claims 2 to 5, characterized in that: At least one vertical chamber located in the third area of ​​the dust collector housing constitutes the first reaction compartment, and a tortuous flow channel is formed in the first reaction compartment through an internal flow guide structure.

8. The dust collector according to any one of claims 1 to 5, characterized in that: At least the first filter structure of the first filter structure and the second filter structure adopts a metal filter element or a ceramic filter element.

9. The dust collector according to any one of claims 1 to 5, characterized in that: The first gas-phase impurities mainly include sulfur dioxide, and the reactant includes a desulfurizing agent.

10. The dust collector according to any one of claims 1 to 5, characterized in that: It is also assembled with a second reaction unit, which adopts an SCR denitration reaction unit and is arranged between the flue gas outlet of the second filter unit and the exhaust structure. The SCR denitration reaction unit is used to receive the flue gas output by the second filter unit and added with the SCR denitration reducing agent and output the denitrated treated flue gas after passing through the SCR denitration catalyst.

11. The dust collector according to any one of claims 1 to 5, characterized in that: The flue gas to be treated is industrial silicon smelting flue gas, then the first solid phase impurities mainly include microsilicon powder, the first gas phase impurities mainly include sulfur dioxide, and the reactant includes a desulfurizer.

12. The dust collector according to any one of claims 1 to 5, characterized in that: It is rebuilt in the dust collector box of an already used dust collector.

13. The dust collector according to any one of claims 1 to 5, characterized in that: During operation, the filtering wind speed of at least one of the first filter unit and the second filter unit is 0.8 m / min-1.5 m / min.

14. A flue gas purification system, including a dust collector, characterized in that: The dust collector adopts the dust collector according to any one of claims 1 to 13.

15. The flue gas purification system according to claim 14, characterized in that: A waste heat recovery device is provided before the dust collector, and the flue gas to be treated is output by the waste heat recovery device.

16. The flue gas purification system according to claim 15, characterized in that: The temperature of the flue gas to be treated output by the waste heat recovery device is 180℃-450℃; an SCR denitrification reaction unit is also provided after the second filter unit, and the SCR denitrification reaction unit is independent of the dust collector or assembled on the dust collector. The SCR denitrification reaction unit is used to receive the flue gas output by the second filter unit and added with the SCR denitrification reductant and output the denitrified flue gas after passing through the SCR denitrification catalyst.

17. The flue gas purification system according to claim 16, characterized in that: The flue gas to be treated is industrial silicon smelting flue gas, then the first solid phase impurities mainly include microsilicon powder, the first gas phase impurities mainly include sulfur dioxide, and the reactant includes a desulfurizer.

18. A method for constructing a dust collector, characterized in that: A dust collector box of an existing dust collector is modified and constructed to obtain a dust collector as claimed in any one of claims 1 to 13.

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