Vapor compression ammonia distilling and absorbing device

Abstract

The utility model provides a vapor compression ammonia distilling and absorbing device, and relates to the technical field of ammonia-containing wastewater treatment. Comprising an ammonia still, a steam compressor and an absorption tower, the steam compressor is connected between the ammonia still and the absorption tower, and the steam compressor is used for compressing low-temperature and low-pressure steam generated in the ammonia absorption process of the absorption tower. Through the arrangement of the ammonia distillation tower, the steam compressor and the absorption tower, low-temperature and low-pressure steam generated in the ammonia absorption process of the absorption tower is converted into high-temperature steam and conveyed to the ammonia distillation tower to drive the ammonia distillation tower to distill ammonia, so that the steam in the ammonia distillation and absorption process can be recycled, external steam is not consumed, the ammonia distillation cost is reduced, and secondary pollution is reduced.

Description

Technical Field

[0001] This utility model relates to the field of ammonia-containing wastewater treatment technology, and more specifically, to a steam compression ammonia stripping and absorption device. Background Technology

[0002] Ammonia-containing wastewater is a common pollutant generated during industrial production. In existing technologies, the ammonia removal process is often used to remove ammonia from ammonia-containing wastewater. The traditional ammonia removal technology involves passing high-temperature steam into an ammonia stripping tower. Ammonia-containing wastewater is sprayed downwards from the top of the tower, while high-temperature steam enters upwards from the bottom, causing the ammonia-containing wastewater and high-temperature steam to form a countercurrent flow and heat transfer. This causes the ammonia-containing wastewater to reach its boiling point, and the ammonia evaporates and escapes. The ammonia is then drawn into an absorption tower by an induced draft fan for absorption, resulting in a high concentration of ammonia water. This process requires external steam and also consumes a large amount of circulating cooling water to cool the acidic ammonia absorption liquid, thus making the ammonia stripping cost high.

[0003] Traditional stripping methods use air to strip ammonia-containing wastewater. A blower sends air into a stripping tower, where it is stripped counter-currently with the ammonia wastewater. The ammonia-containing air exiting the tower enters an absorption tower, where the ammonia is absorbed by an acidic liquid before being released. This process often results in ammonia contamination in the released air and has been largely phased out. Reports indicate that closed-loop stripping methods, where air is not released but recycled for ammonia stripping, can reduce pollution. However, because this air stripping method lacks heat support, its stripping capacity is weak, requiring a large air volume, typically an air-to-water ratio of around 3500:1, leading to high costs. Therefore, we have proposed an improvement: a steam compression ammonia stripping and absorption device. Utility Model Content

[0004] The purpose of this invention is to address the problems of high cost and secondary pollution associated with current ammonia-containing wastewater treatment processes.

[0005] In order to achieve the above-mentioned objectives, this utility model provides a steam compression ammonia stripping and absorption device to improve the above-mentioned problems.

[0006] The application is as follows:

[0007] A steam compression ammonia stripping and absorption device includes an ammonia stripping tower, a steam compressor, and an absorption tower. The steam compressor is connected between the ammonia stripping tower and the absorption tower and is used to compress the low-temperature, low-pressure steam generated during the ammonia absorption process in the absorption tower.

[0008] As a preferred technical solution of this application, the ammonia stripping tower is connected to an ammonia water conveying structure, which is used to convey ammonia water to the ammonia stripping tower.

[0009] As a preferred technical solution of this application, the ammonia water conveying structure includes a material tank connected to the ammonia stripping tower, the material tank being connected to a material circulation pump, and the material circulation pump being connected to the ammonia stripping tower.

[0010] As a preferred technical solution of this application, the absorption tower is connected to an acidic ammonia absorption liquid circulation structure.

[0011] As a preferred technical solution of this application, the acidic ammonia absorption liquid circulation structure includes a storage tank connected to the absorption tower, the storage tank being connected to an acidic ammonia absorption liquid circulation pump, and the acidic ammonia absorption liquid circulation pump being connected to the absorption tower.

[0012] As a preferred technical solution of this application, a vacuum generating device is connected between the absorption tower and the storage tank.

[0013] As a preferred technical solution of this application, the vacuum generating device includes an ejector circulation pump connected to a liquid storage tank, the ejector circulation pump is connected to a hydraulic ejector, and the hydraulic ejector is connected to an absorption tower.

[0014] As a preferred technical solution of this application, an induced draft fan is connected between the ammonia stripping tower and the absorption tower.

[0015] As a preferred technical solution of this application, a steam-water separator is provided at the air inlet of the steam compressor. When steam mixed with liquid droplets enters the air inlet of the steam compressor, the steam-water separator can effectively separate the liquid droplets carried in the steam by means of its special separation mechanism. This reduces the amount of liquid droplets entering the steam compressor with the steam from the source, successfully avoids the occurrence of liquid slugging, effectively protects the compressor from damage, significantly extends the service life of the compressor, and ensures the stable and orderly operation of the entire steam compression process.

[0016] As a preferred technical solution of this application, the storage tank is equipped with a stirrer, which includes a stirring shaft located at the center of the storage tank and double-layer blades installed on the stirring shaft. The upper blade is a slanted turbine type, and the lower blade is an anchor type. Stirring makes the composition of the acidic ammonia absorption liquid uniform, avoids precipitation and accumulation, and ensures stable ammonia absorption effect.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] In the scheme of this application:

[0019] Compared with the traditional stripping method, the advantages of this technology are as follows:

[0020] To address the issues of high cost and secondary pollution in existing ammonia wastewater treatment processes, this application proposes an ammonia stripping tower, a steam compressor, and an absorption tower. The low-temperature, low-pressure steam generated during ammonia absorption in the absorption tower is converted into high-temperature steam and transported to the ammonia stripping tower to drive ammonia stripping. This allows the steam to be recycled during the ammonia stripping and absorption process, without consuming external steam, thus reducing ammonia stripping costs and secondary pollution. Attached Figure Description

[0021] Figure 1 A schematic diagram of the vapor compression ammonia stripping and absorption device provided in this application;

[0022] Figure 2 A schematic diagram of another embodiment of the vapor compression ammonia stripping and absorption apparatus provided in this application;

[0023] Figure 3 A partial schematic diagram of the vapor compression ammonia stripping and absorption device provided in this application;

[0024] The image shows:

[0025] 1. Ammonia stripping tower; 2. Steam compressor; 3. Absorption tower; 4. Storage tank; 5. Acidic ammonia absorption liquid circulation pump; 6. Ejector circulation pump; 7. Hydraulic ejector; 8. Material tank; 9. Material circulation pump; 10. Exhaust fan. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] Example 1, please refer to Figure 1 and Figure 3A steam compression ammonia stripping and absorption device includes an ammonia stripping tower 1, a steam compressor 2, and an absorption tower 3. The steam compressor 2 is connected between the ammonia stripping tower 1 and the absorption tower 3. The steam compressor 2 is used to compress the low-temperature, low-pressure steam generated during the ammonia absorption process in the absorption tower 3. After being compressed by the steam compressor 2, the low-temperature, low-pressure steam generated during the ammonia absorption process in the absorption tower 3 is converted into high-temperature steam and transported to the ammonia stripping tower 1 to drive the ammonia stripping in the ammonia stripping tower 1. This achieves efficient energy recycling, significantly reduces energy consumption and production costs, and improves the operational stability and sustainability of the entire device. By converting the low-temperature, low-pressure steam generated in the absorption tower 3 into high-temperature steam for reuse in the ammonia stripping tower 1, steam waste is reduced, allowing energy to be reused multiple times within the system. This not only reduces the input of external energy and lowers the energy procurement costs for enterprises, but also reduces the environmental burden such as carbon emissions generated by energy production. Moreover, the stable steam circulation supply ensures the continuity and stability of the ammonia stripping process, reduces the risk of production interruption due to unstable steam supply, improves production efficiency and product quality stability, and lays a solid foundation for the long-term stable production of enterprises.

[0030] Furthermore, such as Figure 1 As shown, the ammonia stripping tower 1 is connected to an ammonia water conveying structure, which is used to convey ammonia water to the ammonia stripping tower 1. The ammonia water conveying structure includes a material tank 8 connected to the ammonia stripping tower 1, and a material circulation pump 9 connected to the material tank 8. The material circulation pump 9 is connected to the ammonia stripping tower 1. This effectively ensures the stable delivery and efficient recycling of ammonia water, greatly improves the ammonia stripping efficiency and raw material utilization rate, and at the same time reduces the waste and treatment cost of ammonia water. The material circulation pump 9 can continuously and stably deliver the ammonia water in the material tank 8 to the top of the ammonia stripping tower 1 for spraying, so that the ammonia water and steam can fully contact and exchange heat, promoting the evaporation of ammonia. This uniform and stable spraying method ensures the high efficiency of the ammonia stripping process, reduces the residue of ammonia in the ammonia stripping tower 1, and improves the ammonia recovery rate. At the same time, the qualified water after ammonia removal flows back to the material tank 8 and mixes with the original ammonia water to participate in ammonia stripping again, reducing the waste of qualified water and maximizing the utilization of resources. The material tank 8 has two chambers, which are used to inject the original ammonia water and collect the qualified water after ammonia removal in the ammonia stripping tower 1, respectively.

[0031] Furthermore, such as Figure 1As shown, the absorption tower 3 is connected to an acidic ammonia absorption liquid circulation structure. This structure includes a storage tank 4 connected to the absorption tower 3, and an acidic ammonia absorption liquid circulation pump 5 connected to the storage tank 4. This connection ensures efficient recycling of the acidic ammonia absorption liquid, significantly enhancing the ammonia absorption effect and effectively reducing the consumption and procurement costs of the acidic ammonia absorption liquid. Simultaneously, it improves the ammonia absorption efficiency and the overall environmental performance of the device. The acidic ammonia absorption liquid circulation pump 5 continuously delivers the acidic ammonia absorption liquid from the storage tank 4 to the absorption tower 3, ensuring that the absorption tower 3 always has sufficient acidic ammonia absorption liquid to absorb ammonia. This guarantees the continuity and efficiency of the ammonia absorption process. The ample supply of acidic ammonia absorption liquid allows for more complete absorption of ammonia, reducing ammonia emissions, lowering the risk of environmental pollution, and improving both economic and environmental benefits for the enterprise, achieving a win-win situation for both the economy and the environment.

[0032] Example 2 further optimizes the vapor compression ammonia stripping and absorption device provided in Example 1. Specifically, the vacuum generating device includes an ejector circulation pump 6 connected to the storage tank 4. The ejector circulation pump 6 is connected to a hydraulic ejector 7, which is connected to the absorption tower 3. The ejector circulation pump 6 and the hydraulic ejector 7 work together to extract non-condensable gases such as air from the device, thereby creating a vacuum environment inside the device. The ejector circulation pump 6 first pressurizes the liquid in the storage tank 4, giving the liquid sufficient kinetic energy to form a high-speed liquid flow. The high-speed liquid flow is transported to the hydraulic ejector 7. The internal structural design of the hydraulic ejector 7 ensures that the liquid flow velocity is high when passing through the nozzle. As the flow rate increases further and rapidly, according to Bernoulli's principle, the surrounding pressure decreases as the flow rate increases, thus creating a negative pressure zone inside the hydraulic ejector 7. This negative pressure zone is connected to the interior of the device, and non-condensable gases such as air inside the device are drawn into the hydraulic ejector 7 under the action of the pressure difference. Subsequently, the drawn-in gas is fully mixed with the high-speed liquid flow, and the liquid flow carrying the gas is discharged together. This cycle repeats continuously, thereby continuously extracting non-condensable gases such as air from the device, maintaining the vacuum environment inside the device, ensuring that the ammonia stripping and absorption process proceeds efficiently and stably, and avoiding adverse effects of non-condensable gases on the reaction process and equipment performance.

[0033] Example 3 further optimizes the steam compression ammonia stripping and absorption device provided in Example 1 or 2, specifically, as follows: Figure 2 As shown, an induced draft fan 10 is connected between the ammonia stripping tower 1 and the absorption tower 3. The induced draft fan 10 facilitates the transport of ammonia gas generated in the ammonia stripping tower 1 to the absorption tower 3. In other words, the suction force generated by the induced draft fan 10 enables the ammonia gas stripped from the ammonia stripping tower 1 to be transported to the absorption tower 3 more quickly, shortening the ammonia transport time and making the entire ammonia stripping and absorption process more stable and efficient.

[0034] A steam-water separator is installed at the air inlet of the steam compressor 2. When steam mixed with liquid droplets enters the air inlet of the steam compressor 2, the steam-water separator can effectively separate the liquid droplets carried in the steam by means of its special separation mechanism. This reduces the amount of liquid droplets entering the steam compressor 2 with the steam from the source, successfully avoids the occurrence of liquid slugging, effectively protects the compressor from damage, significantly extends the service life of the compressor, and ensures the stable and orderly operation of the entire steam compression process.

[0035] The storage tank 4 is equipped with a stirrer, which includes a stirring shaft located in the center of the storage tank 4 and double-layer blades mounted on the stirring shaft. The upper blade is a slanted turbine type, and the lower blade is an anchor type. Stirring makes the acidic ammonia absorption liquid uniform in composition, avoids precipitation and accumulation, and ensures stable ammonia absorption effect.

[0036] In operation, initial steam is supplied to the steam compressor 2, which delivers high-temperature steam to the bottom of the ammonia stripping tower 1. The raw ammonia water in the tank 8 is pumped to the top of the ammonia stripping tower 1 by the material circulation pump 9 for spraying. The qualified water after ammonia removal flows back into the tank 8. Part of the qualified water in the tank 8 is discharged after meeting standards, while the other part is mixed with the raw ammonia water and then pumped back into the ammonia stripping tower 1 by the material circulation pump 9 for ammonia stripping. The raw ammonia water undergoes countercurrent heat exchange with the high-temperature steam entering from the bottom of the ammonia stripping tower 1, resulting in continuous ammonia stripping from the raw ammonia water, which then flows towards the top of the ammonia stripping tower 1. The ammonia gas and some water vapor produced during ammonia stripping are drawn into the absorption tower 3 from the top of the ammonia stripping tower 1, where the ammonia gas is absorbed. The acidic ammonia-absorbing liquid in tower 3 absorbs ammonia and generates ammonium salt solution. The heat generated by ammonia absorption and the water vapor carried by ammonia stripping produce low-temperature water vapor at the top of absorption tower 3. The low-temperature water vapor is sent to steam compressor 2, where it is pressurized and converted into high-temperature water vapor, which is then sent back to the bottom of ammonia stripping tower 1 for ammonia stripping. The temperature of the low-temperature acidic ammonia-absorbing liquid increases after ammonia absorption in absorption tower 3 and flows back to the storage tank 4. Acidic ammonia-absorbing water is used for ammonia absorption, which enables the generation of non-volatile ammonium salts, such as ammonium sulfate, during the ammonia absorption process. Only in this way will ammonia gas not be evaporated from the top of absorption tower 3. Otherwise, the ammonia gas will be evaporated and returned to ammonia stripping tower 1 via steam compressor 2. Therefore, this application is suitable for ammonia removal from wastewater.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0038] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A steam compression ammonia stripping and absorption device, characterized in that, It includes an ammonia stripping tower (1), a steam compressor (2), and an absorption tower (3). The steam compressor (2) is connected between the ammonia stripping tower (1) and the absorption tower (3). The steam compressor (2) is used to compress the low-temperature and low-pressure steam generated during the ammonia absorption process in the absorption tower (3). A steam-water separator is provided at the air inlet of the steam compressor (2). The absorption tower (3) is connected to an acidic ammonia absorption liquid circulation structure, which includes a storage tank (4) connected to the absorption tower (3), and an acidic ammonia absorption liquid circulation pump (5) connected to the absorption tower (3). The storage tank (4) is equipped with a stirrer, which includes a stirring shaft located at the center of the storage tank (4) and double-layer blades mounted on the stirring shaft. The upper blade is a slanted turbine type, and the lower blade is an anchor type.

2. The steam compression ammonia stripping and absorption device according to claim 1, characterized in that, The ammonia stripping tower (1) is connected to an ammonia water conveying structure, which is used to convey ammonia water to the ammonia stripping tower (1).

3. The steam compression ammonia stripping and absorption device according to claim 2, characterized in that, The ammonia water conveying structure includes a material tank (8) connected to the ammonia stripping tower (1), the material tank (8) being connected to a material circulation pump (9), and the material circulation pump (9) being connected to the ammonia stripping tower (1).

4. The steam compression ammonia stripping and absorption device according to claim 1, characterized in that, A vacuum generator is connected between the absorption tower (3) and the storage tank (4).

5. The steam compression ammonia stripping and absorption device according to claim 4, characterized in that, The vacuum generating device includes an ejector circulation pump (6) connected to a liquid storage tank (4), an ejector circulation pump (6) connected to a hydraulic ejector (7), and the hydraulic ejector (7) connected to an absorption tower (3).

6. The steam compression ammonia stripping and absorption device according to claim 1, characterized in that, An induced draft fan (10) is connected between the ammonia stripping tower (1) and the absorption tower (3).

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