Complex flue gas treatment system

Abstract

The present invention discloses a complex flue gas treatment system, which includes: a primary scrubber, which is connected to a first flue gas source; a secondary scrubber, which is connected to the primary scrubber and a second flue gas source; a cooling tower, which is connected to the secondary scrubber; an electric demister, which is connected to the cooling tower, and an outlet of the electric demister is connected to a desulfurization tower. The complex flue gas treatment system according to the embodiment of the present invention has the advantages of good treatment effect, high efficiency, low cost, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and in particular to a complex flue gas treatment system. Background Art

[0002] The smelting and chemical production processes generate multiple high-temperature flue gases with widely varying dust concentrations, sulfur dioxide, and water-containing flue gases, which need to be treated before being discharged.

[0003] The methods for treating complex flue gases in related technologies include a cyclone tower combined with a high-efficiency scrubber, or treating two flue gases separately. The method of using a cyclone tower combined with a high-efficiency scrubber has a low dust removal efficiency because the dust content in the flue gas is relatively high. After a period of production, there is a possibility of baffle collapse, affecting subsequent production. Treating two flue gases separately results in an increase in the number of equipment, a longer process, a large footprint, high investment, and high operating costs. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a complex flue gas treatment system, which has the advantages of good treatment effect, high efficiency and low cost.

[0005] To achieve the above-mentioned purpose, a complex flue gas treatment system is proposed according to an embodiment of the present invention, and the complex flue gas treatment system includes: a first-level scrubber, which is connected to a first flue gas source; a second-level scrubber, which is connected to the first-level scrubber and a second flue gas source; a cooling tower, which is connected to the second-level scrubber; an electrostatic demister, which is connected to the cooling tower, and the outlet of the electrostatic demister is connected to a desulfurization tower.

[0006] The complex flue gas treatment system according to the embodiment of the present invention has the advantages of good treatment effect, high efficiency and low cost.

[0007] In addition, the complex flue gas treatment system according to the above embodiment of the present invention may also have the following additional technical features:

[0008] According to one embodiment of the present invention, the first-stage scrubber is provided with a first reverse spray pipe, and the first-stage scrubber is connected to the first flue gas source through the first reverse spray pipe, and the second-stage scrubber is provided with a second reverse spray pipe and a third reverse spray pipe, and the second-stage scrubber is connected to the first-stage scrubber through the second reverse spray pipe and connected to the second flue gas source through the third reverse spray pipe.

[0009] According to one embodiment of the present invention, the complex flue gas treatment system also includes a first circulation pipe and a second circulation pipe, the first circulation pipe is respectively connected to the lower part of the first-stage scrubber and the first reverse spray pipe, and the second circulation pipe is respectively connected to the lower part of the second-stage scrubber, the second reverse spray pipe, the first-stage scrubber and the third reverse spray pipe.

[0010] According to one embodiment of the present invention, the complex flue gas treatment system further includes a sedimentation tank, the sedimentation tank is connected to the first circulation pipe, and the lower end of the sedimentation tank is connected to the filter press.

[0011] According to one embodiment of the present invention, the complex flue gas treatment system further includes a first clear liquid tank, the sedimentation tank has a supernatant liquid outlet, and the supernatant liquid outlet is connected to the first clear liquid tank.

[0012] According to one embodiment of the present invention, the complex flue gas treatment system further includes a second clear liquid tank, and the second clear liquid tank is connected to the cooling tower.

[0013] According to one embodiment of the present invention, the complex flue gas treatment system also includes an emergency high-level tank, which is connected to the second clear liquid tank, and the second clear liquid tank is connected to the bottom of the first clear liquid tank. A clear liquid pump is connected between the second clear liquid tank and the emergency high-level tank for pumping the liquid in the second clear liquid tank to the emergency high-level tank. The emergency high-level tank is connected to at least one of the first reverse spray pipe, the second reverse spray pipe and the third reverse spray pipe.

[0014] According to one embodiment of the present invention, the bottom wall of the emergency high-level tank is in the shape of a cone with the middle portion protruding downwards compared to the outer periphery.

[0015] According to one embodiment of the present invention, the first reverse spray pipe is tangentially connected to the primary scrubber, the second reverse spray pipe is tangentially connected to the secondary scrubber, and the third reverse spray pipe is tangentially connected to the secondary scrubber.

[0016] According to an embodiment of the present invention, the cooling tower cools the gas by circulating water, the cooling tower is connected to a circulating water pipe, and the circulating water pipe is connected to a dilute acid cooler.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1Schematic diagram of the structure of a complex flue gas treatment system according to an embodiment of the present invention.

[0020] Figure numerals: complex flue gas treatment system 1, primary scrubber 10, first reverse spray pipe 11, secondary scrubber 20, second reverse spray pipe 21, third reverse spray pipe 22, cooling tower 30, circulating water pipe 31, dilute acid cooler 32, electrostatic demister 40, fan 41, first circulation pipe 51, second circulation pipe 52, sedimentation tank 60, first clear liquid tank 71, second clear liquid tank 72, accident high-level tank 80, first flue gas source 2, second flue gas source 3, desulfurization tower 4, filter press 5, air quenching device 6, cooling water supply 7, cooling water return 8, process new water 9. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The complex flue gas treatment system 1 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0025] like Figure 1As shown, the complex flue gas treatment system 1 according to an embodiment of the present invention includes a primary scrubber 10 , a secondary scrubber 20 , a cooling tower 30 and an electric demisting device 40 .

[0026] The primary scrubber 10 is connected to the first flue gas source 2. The secondary scrubber 20 is connected to the primary scrubber 10 and the second flue gas source 3. The cooling tower 30 is connected to the secondary scrubber 20. The electric mist eliminator 40 is connected to the cooling tower 30, and the outlet of the electric mist eliminator 40 is connected to the desulfurization tower 4.

[0027] It can be understood by those skilled in the art that the complex flue gas treatment system 1 is used to treat complex flue gas, and the first flue gas source 2 and the second flue gas source 3 come from different flue gas sources, and the dust content, water content, operation time, etc. of the flue gas at the two places can be different. For example, the first flue gas source 2 can be flue gas generated by air quenching or water quenching of matte, and the second flue gas source 3 can be flue gas generated by air quenching or water quenching of blowing slag.

[0028] Specifically, the flue gas from the first flue gas source 2 enters the primary scrubber 10, the secondary scrubber 20, the cooling tower 30 and the electric demister 40 in sequence, undergoes two-stage washing, cooling and demisting in sequence, and then passes through the desulfurization tower 4 for desulfurization before being discharged. The flue gas from the second flue gas source 3 enters the secondary scrubber 20, the cooling tower 30 and the electric demister 40 in sequence, undergoes washing in the secondary scrubber 20, cooling and demisting, and then passes through the desulfurization tower 4 for desulfurization before being discharged.

[0029] According to the complex flue gas treatment system 1 of the embodiment of the present invention, by passing the high-concentration and difficult-to-treat flue gas through the first-level scrubber 10 and the second-level scrubber 20 for washing twice in succession, the treatment effect of the flue gas can be guaranteed. Compared with the technical solution of the combination of a cyclone tower and a scrubber in the related art, the flue gas treatment effect can be effectively improved. The low-concentration and easier-to-treat flue gas is passed through the second-level scrubber 20 for a single washing. Different flue gases can be selected using different washing processes, and different flue gases can be treated in a targeted manner, so that the complex flue gas treatment system 1 can treat complex flue gases. Compared with the technical solution of using a cyclone tower in combination with a scrubber in the related art, the flue gas treatment efficiency can be effectively improved, and the problem of baffle collapse due to high dust content can be avoided.

[0030] Furthermore, since the two flue gases of the complex flue gas treatment system 1 use the same equipment in the secondary scrubber 20 and subsequent processes, compared with the method of separately treating the two flue gases in the related art, the number of equipment can be greatly reduced, the total process flow can be reduced, the equipment footprint can be reduced, and the equipment cost and operating cost can be reduced.

[0031] Therefore, the complex flue gas treatment system 1 according to the embodiment of the present invention has the advantages of good treatment effect, high efficiency, low cost, etc.

[0032] The complex flue gas treatment system 1 according to a specific embodiment of the present invention is described below with reference to the accompanying drawings.

[0033] In some specific embodiments of the present invention, Figure 1 As shown, the complex flue gas treatment system 1 according to an embodiment of the present invention includes a primary scrubber 10 , a secondary scrubber 20 , a cooling tower 30 and an electric demisting device 40 .

[0034] Advantageously, if Figure 1 As shown, the first scrubber 10 is provided with a first reverse spray pipe 11, and the first scrubber 10 is connected to the first flue gas source 2 through the first reverse spray pipe 11, and the second scrubber 20 is provided with a second reverse spray pipe 21 and a third reverse spray pipe 22, and the second scrubber 20 is connected to the first scrubber 10 through the second reverse spray pipe 21 and is connected to the second flue gas source 3 through the third reverse spray pipe 22. Specifically, the reverse spray pipe can form a foam zone in the reverse spray pipe through the collision of fluids in opposite directions. Since the flue gas contacts a large area and constantly renewed liquid surface, particle capture and gas absorption occur in the foam zone, and heat transfer is performed accordingly, thereby achieving flue gas purification and flue gas temperature reduction.

[0035] Furthermore, there may be a plurality of first reverse spray pipes 11, a plurality of second reverse spray pipes 21, and a plurality of third reverse spray pipes 22. This can further improve the flexibility of the arrangement of the scrubber and the reverse spray pipes.

[0036] Specifically, Figure 1 As shown, the complex flue gas treatment system 1 further includes a first circulation pipe 51 and a second circulation pipe 52. The first circulation pipe 51 is respectively connected to the lower part of the primary scrubber 10 and the first reverse spray pipe 11, and the second circulation pipe 52 is respectively connected to the lower part of the secondary scrubber 20, the second reverse spray pipe 21, the primary scrubber 10 and the third reverse spray pipe 22. Specifically, the washing liquid in the primary scrubber 10 is circulated through the first circulation pipe 51, and the washing liquid in the secondary scrubber 20 is circulated through the second circulation pipe 52. In this way, the washing liquid in the primary scrubber 10 and the secondary scrubber 20 can be circulated, thereby improving the washing effect and saving resources.

[0037] More advantageously, if Figure 1 As shown, the complex flue gas treatment system 1 further includes a sedimentation tank 60, which is connected to the first circulation pipe 51, and the lower end of the sedimentation tank 60 is connected to the filter press 5. In this way, a part of the washing water circulated in the first circulation pipe 51 can flow into the sedimentation tank 60 for sedimentation to achieve solid-liquid separation, and the separated solids are processed by the filter press 5 and then sent to other processes.

[0038] More specifically, Figure 1As shown, the complex flue gas treatment system 1 further includes a first clear liquid tank 71, and the sedimentation tank 60 has a supernatant outlet, which is connected to the first clear liquid tank 71. In this way, the upper clear liquid after sedimentation in the sedimentation tank 60 can be stored in the first clear liquid tank 71 for use in other processes.

[0039] Furthermore, if Figure 1 As shown, the complex flue gas treatment system 1 further includes a second clear liquid tank 72, which is connected to the cooling tower 30. In this way, the second clear liquid tank 72 can be used to store the clear liquid at the cooling tower 30 for use in other processes.

[0040] Figure 1 A complex flue gas treatment system 1 according to a specific example of the present invention is shown. Figure 1 As shown, the complex flue gas treatment system 1 also includes an accident high-level tank 80, which is connected to the second clear liquid tank 72, and the second clear liquid tank 72 is connected to the bottom of the first clear liquid tank 71. A clear liquid pump for pumping the liquid in the second clear liquid tank 72 to the accident high-level tank 80 is connected between the second clear liquid tank 72 and the accident high-level tank 80, and the accident high-level tank 80 is connected to at least one of the first reverse spray pipe 11, the second reverse spray pipe 21 and the third reverse spray pipe 22. In this way, the accident high-level tank 80 can be used to store liquid to be used as the accident nozzle and top overflow weir of the first scrubber 10 and the second scrubber 20.

[0041] Advantageously, if Figure 1 As shown, the bottom wall of the accident high-level tank 80 is a cone with the middle part protruding downwards compared with the outer periphery. This can facilitate the discharge of the liquid in the accident high-level tank 80.

[0042] Specifically, Figure 1 As shown, the first reverse jet pipe 11 is tangentially connected to the primary scrubber 10, the second reverse jet pipe 21 is tangentially connected to the secondary scrubber 20, and the third reverse jet pipe 22 is tangentially connected to the secondary scrubber 20. Specifically, anti-swirl plates may be provided on the tops of the primary scrubber 10 and the secondary scrubber 20. In this way, dust particles of smoke washed down by the reverse jet pipe can be separated by swirl flow to reduce the dust particles brought into subsequent equipment.

[0043] Of course, the first reverse spray pipe 11, the second reverse spray pipe 21 and the third reverse spray pipe 22 may be partially tangentially connected or may not be tangentially connected.

[0044] Alternatively, if Figure 1 As shown, the cooling tower 30 cools the gas by circulating water, and the cooling tower 30 is connected to a circulating water pipe 31, and the circulating water pipe 31 is connected to a dilute acid cooler 32. Specifically, the circulating water pipe 31 is respectively connected to the cooling water supply 7 and the cooling water return 8. In this way, the cooling effect can be ensured, and the equipment and resource costs can be reduced.

[0045] Specifically, the electric mist removal device 40 can be connected to the desulfurization tower 4 through the fan 41. The first clear liquid tank 71 can be connected to the wind quenching device 6 to use the stored water for the wind quenching device 6. The cooling tower 30 can be connected to the process fresh water 9 to replenish the process fresh water. In addition, in order to prevent sudden power outages and pump stop accidents during the production process and to avoid excessively high flue gas temperatures and burnout of equipment, an overflow weir is set at the top of the reverse spray pipe, an emergency nozzle is set in the reverse spray pipe, and an emergency water valve is set outside as supporting protection measures.

[0046] Reference below Figure 1 The working process of the complex flue gas treatment system 1 according to an embodiment of the present invention is described.

[0047] For example, the first flue gas source 2 is matte air-quenched or water-quenched flue gas, and the second flue gas source 3 is blowing slag air-quenched or water-quenched flue gas.

[0048] The matte air-quenched or water-quenched flue gas first enters the first reverse spray pipe 11 of the primary scrubber 10, collides with the liquid sprayed in reverse from the large-diameter nozzle, and forces the liquid to radially shoot toward the cylinder wall from the inside to the outside, thus establishing a foam zone with a certain height at the gas-liquid interface.

[0049] According to the relative momentum of gas and liquid, the foam column moves up and down along the cylinder. As the flue gas contacts the large and constantly renewed liquid surface, particles are captured and gas is absorbed in the foam area, and heat is transferred accordingly, thereby achieving flue gas purification and flue gas temperature reduction.

[0050] Then the flue gas and circulating liquid enter the primary scrubber 10 for gas-liquid separation, and the separated gas enters the second reverse spray pipe 21 of the secondary scrubber 20. Most of the washing liquid directly enters the primary scrubber 10 for recycling, and a small part of the washing liquid is introduced into the sedimentation tank 60 for liquid-solid separation, thereby reducing the wear and tear of equipment and pipelines and the blockage of pipelines caused by the increase of solid content in the circulating liquid. The upper clear liquid of the sedimentation tank 60 enters the first clear liquid tank 71, and the bottom flow is sent to the filter press 5 for filtration.

[0051] The flue gas scrubbed in the primary scrubber 10 enters the second reverse spray pipe 21 of the secondary scrubber 20 for further dust removal.

[0052] The flue gas quenched by air or water from the blowing slag enters the third reverse nozzle 22 of the secondary scrubber 20 for scrubbing and dust removal.

[0053] Similar to the primary scrubber 10, most of the scrubbing liquid is directly recycled, and a small portion of the scrubbing liquid is led to the primary scrubber 10 or the settling tank 60 for liquid-solid separation.

[0054] The flue gas discharged from the secondary scrubber 20 enters the cooling tower 30, where the heat is removed by cooling water, so that the flue gas is further cooled and the water content in the flue gas is reduced. The cooled water is sent to the second clear liquid tank 72, and the clear liquid is pumped from the second clear liquid tank 72 into the top emergency high-level tank 80 by the clear liquid pump, which is used as the emergency nozzle and top overflow weir of the primary scrubber 10 and the secondary scrubber 20.

[0055] The flue gas coming out of the cooling tower 30 enters the electric mist eliminator 40 to remove the acid mist and further remove dust.

[0056] The flue gas from the electric mist eliminator 40 is sent to the desulfurization tower 4 through the fan 41 for desulfurization before being discharged in compliance with the emission standards.

[0057] According to the complex flue gas treatment system 1 of the embodiment of the present invention, multiple reverse spray pipes are provided. Flue gas with high dust content is subjected to multi-stage high-efficiency washing, and flue gas with low dust content is subjected to primary high-efficiency washing. It is suitable for washing two or more flue gases with large differences in dust content and inconsistent running time, which not only ensures washing efficiency but also reduces equipment investment.

[0058] In addition, the water from the cooling tower 30 is sent to the second clean liquid tank 72, and the clean liquid is pumped into the emergency high-level tank 80 by the second clean liquid tank 72, thereby avoiding the mixing of cleaner liquid and dirtier liquid, and allowing the clean liquid to be used as water for the emergency nozzles and top overflow weirs of the first-stage scrubber 10 and the second-stage scrubber 20, so that multiple scrubbers share one emergency high-level tank 80, which greatly saves investment.

[0059] In addition, by optimizing the equipment structures such as the reverse spray pipes of the first-stage scrubber 10 and the second-stage scrubber 20, the first clean liquid tank 71 and the second clean liquid tank 72, and the emergency high-level tank 80, the blockage of the equipment pipelines is effectively avoided and the scrubbing effect of the flue gas is improved.

[0060] Other structures and operations of the complex flue gas treatment system 1 according to the embodiment of the present invention are known to ordinary technicians in the field and will not be described in detail here.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A complex flue gas treatment system, characterized in that: include: a primary scrubber, the primary scrubber being in communication with a first flue gas source; a secondary scrubber, the secondary scrubber being in communication with the primary scrubber and a second flue gas source; a cooling tower, the cooling tower being in communication with the secondary scrubber; An electric demisting device, wherein the electric demisting device is connected to the cooling tower, and an outlet of the electric demisting device is connected to a desulfurization tower; The first-stage scrubber is provided with a first reverse spray pipe, and the first-stage scrubber is connected to the first flue gas source through the first reverse spray pipe. The second-stage scrubber is provided with a second reverse spray pipe and a third reverse spray pipe, and the second-stage scrubber is connected to the first-stage scrubber through the second reverse spray pipe and connected to the second flue gas source through the third reverse spray pipe.

2. The complex flue gas treatment system according to claim 1, characterized in that: It also includes a first circulation pipe and a second circulation pipe, wherein the first circulation pipe is respectively connected to the lower part of the first-stage scrubber and the first reverse spray pipe, and the second circulation pipe is respectively connected to the lower part of the second-stage scrubber, the second reverse spray pipe, the first-stage scrubber and the third reverse spray pipe.

3. The complex flue gas treatment system according to claim 2, characterized in that: It also includes a sedimentation tank, which is connected to the first circulation pipe, and the lower end of the sedimentation tank is connected to the filter press.

4. The complex flue gas treatment system according to claim 3, characterized in that: It also includes a first clear liquid tank, the sedimentation tank has a supernatant outlet, and the supernatant outlet is connected to the first clear liquid tank.

5. The complex flue gas treatment system according to claim 4, characterized in that: It also includes a second clear liquid tank, which is connected to the cooling tower.

6. The complex flue gas treatment system according to claim 5, characterized in that: It also includes an emergency high-level tank, which is connected to the second clear liquid tank, and the second clear liquid tank is connected to the bottom of the first clear liquid tank. A clear liquid pump is connected between the second clear liquid tank and the emergency high-level tank for pumping liquid in the second clear liquid tank to the emergency high-level tank. The emergency high-level tank is connected to at least one of the first reverse spray pipe, the second reverse spray pipe and the third reverse spray pipe.

7. The complex flue gas treatment system according to claim 6, characterized in that: The bottom wall of the emergency high-level tank is in a cone shape with the middle portion protruding downwards compared to the outer circumference.

8. The complex flue gas treatment system according to claim 1, characterized in that: The first reverse spray pipe is tangentially connected to the first-stage scrubber, the second reverse spray pipe is tangentially connected to the second-stage scrubber, and the third reverse spray pipe is tangentially connected to the second-stage scrubber.

9. The complex flue gas treatment system according to claim 1, characterized in that: The cooling tower cools the gas by circulating water. The cooling tower is connected to a circulating water pipe, and the circulating water pipe is connected to a dilute acid cooler.

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