Ammonia desulfurization system

Abstract

The utility model provides an ammonia desulfurization system which comprises an absorption tower, a drying machine, a cyclone group connected between the absorption tower and the drying machine in series, and a return tank connected with the absorption tower through a return pipeline, at least one swirler in the swirler group is connected with the return tank, and the dryer is connected with the return tank through a bypass pipeline. According to the ammonia desulfurization system provided by the utility model, on one hand, the ammonia recovery rate can be improved, the chlorine ion content in the ammonia desulfurization system is reduced, and the corrosion to equipment and an anti-corrosion coating in an absorption tower is reduced, and on the other hand, the equipment use and floor area can be reduced, so that the equipment operation and maintenance cost is reduced; therefore, the technical problems of high equipment operation and maintenance cost, low ammonia recovery rate and unfavorable production benefit improvement caused by more equipment use and larger occupied area in the prior art are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection, in particular to an ammonia desulfurization system. Background Art

[0002] Wet flue gas desulfurization has been widely used in the power, metallurgical and chemical industries due to its advantages such as high desulfurization efficiency and wide adjustment range. In particular, ammonia flue gas desulfurization has been widely used in the power, metallurgical and chemical industries due to its high desulfurization efficiency and wide adjustment range. Ammonia flue gas desulfurization has been widely used in the dual carbon background due to its good absorbent activity, high added value of desulfurization products and no additional carbon emissions. However, due to its own process characteristics, ammonia flue gas desulfurization does not discharge wastewater during actual operation. Therefore, the entire desulfurization system will lead to chloride ion enrichment in long-term operation. However, once the detection data of chloride ions in actual operation exceeds 10,000 ppm, it will cause serious corrosion to the equipment anti-corrosion materials in the absorption tower, thereby affecting the normal operation of the desulfurization system.

[0003] There are currently two main methods for removing wastewater from ammonia desulfurization (which also removes chloride ion content by removing wastewater): 1. Discharge a portion of the slurry to the front of the dust collector, use the heat of the flue gas to evaporate the water in the slurry, and the salts and other solid substances in the slurry enter the dust collector, and fall into the ash hopper after being captured by the dust collector and discharged. 2. Build a separate concentration and drying tower, introduce flue gas from the outlet of the air preheater as a heat source, concentrate and dry the slurry and flue gas in the concentration and drying tower, and transport the dried salts and other solid substances to the dust collector ash conveying system through pneumatic ash conveying.

[0004] However, the above-mentioned ammonia desulfurization system has the following main problems in removing chloride ions: 1. It occupies a large area and uses more equipment (long-distance pipelines, flues, etc. need to be added), which increases investment and operating costs. 2. The ammonia utilization efficiency is low, and part of the ammonia is lost with the discharge, which increases additional costs, or too many ammonium salt impurities are collected and cannot be sold together with the desulfurization by-products. 3. The hot flue gas is drawn from the front section of the dust collector, and the flue gas contains a large amount of ash, which is easy to cause compaction in the drying tower and ash accumulation in the flue.

[0005] Therefore, the above-mentioned prior art has at least the following technical problems: the method used in the prior art to remove chloride ions requires more equipment and occupies a larger area, resulting in high equipment operation and maintenance costs. At the same time, the ammonia recovery rate is low, which is not conducive to improving production efficiency. Utility Model Content

[0006] The embodiment of the present application solves the technical problems of high equipment operation and maintenance costs and low ammonia recovery rate in the prior art by providing an ammonia desulfurization system.

[0007] In order to solve the above technical problems, the present application embodiment provides an ammonia desulfurization system:

[0008] It includes an absorption tower and a dryer, a cyclone group connected in series between the absorption tower and the dryer, and a reflux tank connected to the absorption tower through a reflux pipeline;

[0009] At least one cyclone in the cyclone group is connected to the reflux drum, and the dryer is connected to the reflux drum through a bypass pipeline.

[0010] Furthermore, one end of the bypass pipe communicating with the reflux tank is connected to the reflux pipe.

[0011] Furthermore, a valve body for controlling on-off is provided on the bypass pipe and / or the return pipe.

[0012] Furthermore, a reflux pump set is connected between the reflux pipe and the reflux tank, and the reflux pump set is located upstream of the connection between the bypass pipe and the reflux pipe.

[0013] Furthermore, the reflux pump group includes a first reflux pump and a second reflux pump connected in parallel, and a connecting port between the first reflux pump and the reflux tank is located above a connecting port between the second reflux pump and the reflux tank.

[0014] Furthermore, a reflux branch pipe is connected between the reflux tank and the reflux pipe, and the connection between the reflux branch pipe and the reflux pipe is located midstream of the connection between the reflux pump group and the bypass pipe and the reflux pipe.

[0015] Furthermore, the absorption tower is connected to the cyclone group through a discharge pipe, and a slurry discharge pump is provided on the discharge pipe.

[0016] Furthermore, at least one of the cyclones is connected to the reflux tank via an overflow pipe, and the overflow pipe is used to transport the high-concentration chloride ion slurry overflowing from the cyclone to the reflux tank; and / or, the cyclone group is connected to the dryer via an underflow pipe.

[0017] Furthermore, an atomizing nozzle is provided at one end of the bypass pipe connected to the dryer; and / or an ammonium sulfate packaging system is connected downstream of the dryer.

[0018] Furthermore, the dryer is a vibrating fluidized bed dryer.

[0019] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0020] (1) By connecting the reflux tank to the absorption tower and at least one cyclone to the reflux tank, high-concentration chloride ions can be recycled after entering the slurry reflux tank, avoiding chloride ion loss and improving ammonia recovery and utilization rate. At the same time, a portion of the high-concentration chloride ion slurry can be introduced into the dryer through the bypass pipeline, and the slurry is dried using the waste heat of the dryer to achieve the purpose of reducing the chloride ion content in the ammonia desulfurization system. Therefore, on the one hand, the ammonia recovery rate can be improved while reducing the chloride ion content in the ammonia desulfurization system, reducing corrosion to the equipment and anti-corrosion coating in the absorption tower. On the other hand, the equipment usage and floor space can be reduced, thereby reducing the equipment operation and maintenance costs, thereby solving the technical problem in the prior art that "the method for removing chloride ions uses more equipment and occupies a larger floor space, resulting in high equipment operation and maintenance costs, and at the same time, the ammonia recovery rate is low, which is not conducive to improving production efficiency."

[0021] (2) The bypass pipe is connected to the return pipe, which can make the overall system simpler and help reduce equipment costs.

[0022] (3) The setting of the valve body can control the timing and duration of the slurry in the reflux tank flowing into the bypass pipe or the reflux pipe, which is conducive to adjusting the flow direction and flow rate of the slurry according to the actual chloride ion removal demand.

[0023] (4) By setting up a reflux pump group, slurry transportation power can be provided, which is conducive to transporting the slurry in the reflux tank to the absorption tower or dryer.

[0024] (5) The first reflux pump and the second reflux pump are provided to deliver the corresponding amount of slurry according to the actual reflux demand, thereby meeting the different usage requirements of the system.

[0025] (6) The setting of the reflux branch pipe is conducive to cooperating with the reflux pump group to control the flow of slurry to the absorption tower or dryer.

[0026] (7) A discharge pipe with a slurry discharge pump is provided to facilitate the transportation of the slurry in the absorption tower to the cyclone group.

[0027] (8) The setting of the overflow pipe can transport the high-concentration chloride ion slurry overflowing from the cyclone to the reflux tank, which is conducive to the recycling of the high-concentration chloride ion slurry and improve the ammonia recovery rate and utilization rate.

[0028] (9) The use of atomizing nozzles is helpful in improving the drying efficiency of the slurry.

[0029] (10) The use of vibrating fluidized bed dryer can achieve better drying effect, and the equipment has a wide range of applications and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the structure of the ammonia desulfurization system in the embodiment of the utility model.

[0032] Description of reference numerals:

[0033] 1. Absorption tower; 2. Slurry discharge pump; 3. Discharge pipe; 4. Cyclone group; 5. Overflow pipe; 6. Underflow pipe; 7. Reflux tank; 8. Reflux pump group; 9. Reflux pipe; 10. Valve body; 11. Bypass pipe; 12. Atomizing nozzle; 13. Dryer; 14. Ammonium sulfate packaging system. DETAILED DESCRIPTION

[0034] The embodiment of the present application provides an ammonia-based desulfurization system to solve the technical problems of the prior art method for removing chloride ions, which has the disadvantages of requiring more equipment and occupying a large area, resulting in high equipment operation and maintenance costs, as well as low ammonia recovery rate, which is not conducive to improving production efficiency.

[0035] The technical solution in the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0036] By connecting the reflux tank to the absorption tower, and at least one cyclone to the reflux tank, high-concentration chloride ions can be recycled after entering the slurry reflux tank, avoiding chloride ion loss, so as to improve ammonia recovery and utilization rate. At the same time, a part of the high-concentration chloride ion slurry can be introduced into the dryer through the bypass pipeline, and the slurry is dried by the waste heat of the dryer to achieve the purpose of reducing the chloride ion content in the ammonia desulfurization system. Therefore, on the one hand, the ammonia recovery rate can be improved while reducing the chloride ion content in the ammonia desulfurization system, reducing the corrosion of the equipment and anti-corrosion coating in the absorption tower. On the other hand, the use of equipment and the floor area can be reduced, thereby reducing the equipment operation and maintenance costs, thereby solving the technical problem in the prior art that "the method for removing chloride ions uses more equipment and occupies a larger area, resulting in high equipment operation and maintenance costs, and at the same time, the ammonia recovery rate is low, which is not conducive to the improvement of production efficiency".

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] One or more embodiments of the present application provide an ammonia desulfurization system for reducing the chloride ion content in the system.

[0039] like Figure 1 As shown, an ammonia desulfurization system according to an embodiment of the present application includes an absorption tower 1 and a dryer 13, a cyclone group 4 connected in series between the absorption tower 1 and the dryer 13, and a reflux tank 7 connected to the absorption tower 1 through a reflux pipe 9. In addition, at least one cyclone in the cyclone group 4 is connected to the reflux tank 7, and the dryer 13 is connected to the reflux tank 7 through a bypass pipe 11.

[0040] Among them, the cyclone group 4 of the embodiment of the present application includes multiple cyclones, and the number of cyclones in the cyclone group 4 connected to the reflux tank 7 can be set and adjusted according to the actual demand for transporting high-concentration chloride ions to the reflux tank 7. For example, the number of cyclones connected to the reflux tank 7 is one or two.

[0041] It can be seen from the above description that the ammonia desulfurization system provided in the embodiment of the present application is connected to the absorption tower 1 through the reflux tank 7, and at least one cyclone is connected to the reflux tank 7, so that high-concentration chloride ions can be recycled after entering the slurry reflux tank 7, avoiding chloride ion loss, so as to improve ammonia recovery and utilization rate. At the same time, a portion of the high-concentration chloride ion slurry can be introduced into the dryer 13 through the bypass pipe 11, and the slurry is dried using the waste heat of the dryer 13 to achieve the purpose of reducing the chloride ion content in the ammonia desulfurization system. Therefore, on the one hand, the ammonia recovery rate can be improved while reducing the chloride ion content in the ammonia desulfurization system, reducing the corrosion of the equipment and anti-corrosion coating in the absorption tower 1. On the other hand, the use of equipment and the floor area can be reduced, thereby reducing the equipment operation and maintenance costs, thereby solving the technical problems of the prior art for removing chloride ions, the use of more equipment and the large floor area, resulting in high equipment operation and maintenance costs, and low ammonia recovery rate, which is not conducive to improving production efficiency.

[0042] Still Figure 1 As shown, in some embodiments, one end of the bypass pipe 11 connected to the reflux tank 7 is connected to the reflux pipe 9. The advantage of such a setting is that the system as a whole can be simpler, which helps to reduce equipment costs.

[0043] As a preferred embodiment, a valve body 10 for controlling on-off is provided on both the bypass pipe 11 and the return pipe 9. The setting of the valve body 10 here can control the timing and duration of the slurry in the reflux tank 7 flowing into the bypass pipe 11 or the return pipe 9, which is conducive to adjusting the flow direction and flow rate of the slurry according to the actual chloride ion removal demand.

[0044] Of course, in this embodiment, in addition to providing the valve body 10 on both the bypass pipe 11 and the return pipe 9, the valve body 10 can also be provided only on the bypass pipe 11 or the return pipe 9 according to needs, and the valve body 10 can adopt a switching valve well known to those skilled in the art. Alternatively, if necessary, a three-way valve can be used to replace the valve body 10 on the bypass pipe 11 and the return pipe 9 to reduce the number of parts used and improve system stability.

[0045] In some embodiments, a reflux pump set 8 is connected between the reflux pipe 9 and the reflux tank 7, and the reflux pump set 8 is located upstream of the connection between the bypass pipe 11 and the reflux pipe 9. Thus, the reflux pump set 8 can be used to provide power for slurry transportation, which is conducive to transporting the slurry in the reflux tank 7 to the absorption tower 1 or the dryer 13.

[0046] As a preferred embodiment, the reflux pump group 8 includes a first reflux pump and a second reflux pump in parallel, and the connecting port between the first reflux pump and the reflux tank 7 is located above the connecting port between the second reflux pump and the reflux tank 7. In the specific structure, the connecting port between the first reflux pump and the reflux tank 7 can be preferably arranged on the side wall of the reflux tank 7 near the middle of the height direction of the reflux tank 7, and the connecting port between the second reflux pump and the reflux tank 7 is preferably arranged on the side wall of the reflux tank 7 near the bottom of the reflux tank 7.

[0047] By setting the first reflux pump and the second reflux pump, the corresponding amount of slurry can be delivered according to the actual reflux demand. For example, when delivering a small amount of slurry, only the first reflux pump is turned on, which helps to meet the different usage requirements of the system.

[0048] As a preferred implementation form, a reflux branch pipe is connected between the reflux tank 7 and the reflux pipe 9, and the connection between the reflux branch pipe and the reflux pipe 9 is located midstream of the connection between the reflux pump group 8 and the bypass pipe 11 and the reflux pipe 9.

[0049] It can be understood that the setting of the reflux branch pipe is conducive to cooperating with the reflux pump group 8 to control the flow rate of the slurry flowing to the absorption tower 1 or the dryer 13. In specific implementation, the relevant structural parts not mentioned in the reflux tank 7 of this embodiment can refer to the circulation tank or precipitation circulation tank (including a stirring paddle driven by a driving motor, etc.) known to those skilled in the art. At the same time, one end of the reflux branch pipe connected to the reflux tank 7 can be preferably set at the top of the reflux tank 7 to facilitate the dispersion of the refluxed slurry in the reflux tank 7.

[0050] In some embodiments, the absorption tower 1 is connected to the cyclone group 4 through a discharge pipe 3, a slurry discharge pump 2 is provided on the discharge pipe 3, and one end of the discharge pipe 3 connected to the absorption tower 1 can be preferably arranged at a position near the bottom of the side wall of the absorption tower 1. In this way, the slurry in the absorption tower 1 can be easily transported to the cyclone group 4.

[0051] In some embodiments, at least one cyclone is connected to the reflux tank 7 via an overflow pipe 5 , and the overflow pipe 5 is used to transport the high-concentration chloride ion slurry overflowing from the cyclone to the reflux tank 7 .

[0052] The arrangement of the overflow pipe 5 here can transport the high-concentration chloride ion slurry overflowing from the cyclone to the reflux tank 7, which is conducive to the recovery and utilization of the high-concentration chloride ion slurry to improve the ammonia recovery rate and utilization rate.

[0053] In specific implementation, the number of cyclones connected to the reflux tank 7 in this embodiment can be set and adjusted according to the actual demand for conveying high-concentration chloride ions to the reflux tank 7 as mentioned above. For example, the number of cyclones connected to the reflux tank 7 is one or two.

[0054] Also as a preferred implementation form, the cyclone group 4 is connected to the dryer 13 through an underflow pipe 6, so as to facilitate the slurry treated by the cyclone group 4 to be transported to the dryer 13 for drying treatment.

[0055] In some embodiments, an atomizing nozzle 12 is provided at one end of the bypass pipe 11 connected to the dryer 13, which is conducive to improving the drying efficiency of the slurry. In addition, as a preferred embodiment, an ammonium sulfate packaging system 14 is connected downstream of the dryer 13.

[0056] During specific implementation, the slurry is dried inside the dryer 13 and then enters the ammonium sulfate packaging system 14. The dried salt substances enter the packaging system along with the finished ammonium sulfate, which not only achieves the purpose of reducing the chloride ion content in the system, but also eliminates the need to use additional ash conveying and cleaning equipment, thus saving equipment costs. At the same time, the entire system can operate continuously, thereby improving the degree of automation.

[0057] As a preferred implementation form, the dryer 13 adopts a vibrating fluidized bed dryer, which can achieve better drying effect, and the equipment has a wide range of applications and high stability.

[0058] For example, the specific implementation of the ammonia desulfurization system of the embodiment of the present application is as follows:

[0059] First, the slurry is transported from the absorption tower 1 to the cyclone group 4 through the discharge pipe 3. The slurry treated by the cyclone group 4 enters the dryer 13 through the pipe, and then enters the ammonium sulfate packaging system 14 for packaging treatment, while the slurry in the cyclone with high chloride ion concentration overflows into the reflux tank 7. Among them, the slurry in the reflux tank 7 returns to the absorption tower 1 through the reflux pump group 8, which is easy to cause chloride ion enrichment.

[0060] When the chloride ions in the system are normal, the valve body 10 on the bypass pipe 11 is in a closed state, and the chlorine-containing slurry circulates between the absorption tower 1, the cyclone group 4 and the reflux tank 7, wherein the high-concentration chloride ion slurry is transported from the cyclone group 4 to the reflux tank 7, and the reflux pump group 8 pressurizes the slurry in the reflux tank 7 and returns it to the absorption tower 1 through the reflux pipe 9. When the chloride ions in the system exceed the standard, the valve body 10 on the bypass pipe 11 is opened, and a part of the slurry is sent to the atomizing nozzle 12 through the bypass pipe 11. The chlorine-containing slurry is dried inside the vibrating fluidized bed dryer 13 and then enters the ammonium sulfate packaging system 14, so that the dried salt substances enter the packaging system with the finished ammonium sulfate, which not only achieves the purpose of reducing the chloride ion content of the system, but also eliminates the need to use additional ash conveying and cleaning equipment, saving equipment costs.

[0061] It can be understood that the embodiment of the present application can achieve efficient removal of chloride ions by adding pipelines and corresponding valve bodies 10 to the existing ammonia desulfurization system and making partial modifications. On the one hand, it can effectively reduce the chloride ion content in the desulfurization system and reduce the corrosion of the equipment and anti-corrosion coating in the absorption tower 1. On the other hand, compared with the existing chloride ion removal device, the system has the characteristics of less equipment and parts, small footprint, and higher ammonia recovery rate, which effectively reduces investment and operating costs. Thus, the existing chloride ion removal device is solved, which has many supporting equipment and a long slurry transportation distance, resulting in a large equipment footprint, high operation and maintenance costs, increased operation and maintenance costs, and the problem that the dried salt substances cannot be effectively recovered and ammonia loss is large.

[0062] It should be understood that although the terms "first", "second", etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are used only to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit without departing from the scope of the exemplary embodiments.

[0063] The directional terms such as outer, middle, inner, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0064] The above is only a preferred embodiment of the present application, and is not any formal or substantial limitation to the present application. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be regarded as the protection scope of the present utility model. Any technician familiar with this profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the spirit and scope of the present application, which are equivalent embodiments of the present application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the substantial technology of the present application are still within the scope of the technical solution of the present application.

Claims

1. An ammonia desulfurization system, characterized in that: It comprises an absorption tower (1) and a dryer (13), a cyclone group (4) connected in series between the absorption tower (1) and the dryer (13), and a reflux tank (7) connected to the absorption tower (1) via a reflux pipe (9); At least one cyclone in the cyclone group (4) is connected to the reflux drum (7), and the dryer (13) is connected to the reflux drum (7) via a bypass pipe (11).

2. The ammonia desulfurization system according to claim 1, characterized in that: One end of the bypass pipe (11) communicating with the reflux tank (7) is connected to the reflux pipe (9).

3. The ammonia desulfurization system according to claim 2, characterized in that: The bypass pipe (11) and / or the return pipe (9) is provided with a valve body (10) for controlling on and off.

4. The ammonia desulfurization system according to claim 2, characterized in that: A reflux pump group (8) is connected between the reflux pipe (9) and the reflux tank (7), and the reflux pump group (8) is located upstream of the connection between the bypass pipe (11) and the reflux pipe (9).

5. The ammonia desulfurization system according to claim 4, characterized in that: The reflux pump group (8) comprises a first reflux pump and a second reflux pump connected in parallel, and the connecting port between the first reflux pump and the reflux tank (7) is located above the connecting port between the second reflux pump and the reflux tank (7).

6. The ammonia desulfurization system according to claim 4, characterized in that: A reflux branch pipe is connected between the reflux tank (7) and the reflux pipe (9), and the connection between the reflux branch pipe and the reflux pipe (9) is located midstream of the connection between the reflux pump group (8) and the bypass pipe (11) and the reflux pipe (9).

7. The ammonia desulfurization system according to claim 1, characterized in that: The absorption tower (1) is connected to the cyclone group (4) via a discharge pipe (3), and a slurry discharge pump (2) is provided on the discharge pipe (3).

8. The ammonia desulfurization system according to claim 1, characterized in that: At least one of the cyclones is connected to the reflux tank (7) via an overflow pipe (5), and the overflow pipe (5) is used to transport the high-concentration chloride ion slurry overflowing from the cyclone to the reflux tank (7); and / or the cyclone group (4) is connected to the dryer (13) via an underflow pipe (6).

9. The ammonia desulfurization system according to any one of claims 1 to 8, characterized in that: An atomizing nozzle (12) is provided at one end of the bypass pipe (11) connected to the dryer (13); and / or an ammonium sulfate packaging system (14) is connected downstream of the dryer (13).

10. The ammonia desulfurization system according to claim 9, characterized in that: The dryer (13) is a vibrating fluidized bed dryer.

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