Ammonia tail gas multi-stage absorption device

Abstract

The utility model relates to a multistage absorption device for ammonia tail gas. The multistage absorption device comprises a front-end treatment group, a primary absorption tower, an additional absorption tower group, a refrigeration group, a pure water tank and an ammonia water tank, the front-end treatment group is used for carrying out front-end treatment on ammonia gas, transferring the treated ammonia gas into the first-stage absorption tower and then sequentially transferring the treated ammonia gas into the second-stage absorption tower group, so that the first-stage absorption tower and the second-stage absorption tower are filled with the ammonia gas, the pure water tank provides pure water to the second-stage absorption tower at the tail end, and ammonia water is transferred into the cooler for cooling after the ammonia gas in the second-stage absorption tower is absorbed; the cooled ammonia water is conveyed into the previous-stage secondary absorption tower to absorb ammonia gas until the ammonia water is conveyed into the primary absorption tower, then the ammonia water is conveyed into the ammonia water tank to be stored, the number of the additional absorption tower groups can be flexibly set according to the concentration of the ammonia gas and the concentration of the required ammonia water, and in addition, circulation is formed between the refrigeration group and the cooler to cool the ammonia water; according to the device, the recovery rate of ammonia gas can be improved, and the structure of the device can be flexibly set according to the concentration needing to be absorbed so as to adjust the absorption effect of the ammonia gas.

Description

Technical Field

[0001] The present application relates to the field of ammonia absorption, and in particular to a multi-stage absorption device for ammonia tail gas. Background Art

[0002] There are three commonly used methods for treating ammonia-containing waste gas: chemical method, physical method and biological method. Among them, the chemical method often uses chemical reagents such as dilute sulfuric acid, dilute hydrochloric acid, bleach, magnesium ammonium phosphate, etc. to react with ammonia in the waste gas to generate relatively stable chemical substances or precipitate and separate, so that ammonia no longer enters the air to pollute the atmospheric environment, thereby achieving the purpose of pollution control; the physical method often uses water absorption and temperature difference distillation. To achieve the purpose of pollution control; the biological method uses the aerobic and anaerobic process of microorganisms to convert ammonia in the waste gas into a nutrient source for microorganisms to achieve the purpose of pollution control.

[0003] At present, there is a large amount of ammonia in the tail gas of MOCVD production. After being treated by the existing water absorption technology, the residual ammonia content is between 5% and 10%. As the country's requirements for ammonia nitrogen emissions are getting higher and higher, the existing water absorption treatment technology cannot meet the higher environmental protection requirements. Utility Model Content

[0004] In view of this, the present application proposes a multi-stage absorption device for ammonia tail gas, which can improve the recovery rate of ammonia and can flexibly set the structure of the device according to the required absorption concentration to adjust the absorption effect of ammonia.

[0005] According to one aspect of the present application, there is provided an ammonia tail gas multi-stage absorption device, comprising: a front-end treatment group, a primary absorption tower, an additional absorption tower group, a refrigeration group, a pure water tank and an ammonia water tank.

[0006] The outlet end of the front-end treatment group is connected to the gas phase inlet of the primary absorption tower by a pipeline, the gas phase outlet of the primary absorption tower is connected to the gas phase inlet of the additional absorption tower group by a pipeline, and the liquid phase outlet of the primary absorption tower is connected to the ammonia water tank by a pipeline; the additional absorption tower group includes: a secondary absorption tower and a cooler, the liquid phase pipeline between the secondary absorption tower and the cooler is connected, and the number of the additional absorption tower groups is one or more; when the number of the additional absorption tower groups is one, the number of the secondary absorption tower and the cooler is one, the gas phase outlet of the primary absorption tower is connected to the gas phase inlet of the secondary absorption tower by a pipeline, the outlet end of the pure water tank is connected to the liquid phase inlet of the secondary absorption tower The gas phase pipeline is connected, and the liquid phase pipeline between the cooler and the first-level absorption tower is connected; when the number of the additional absorption tower groups is multiple, the number of the secondary absorption tower and the cooler is equal and is set to multiple, and the multiple additional absorption tower groups are arranged in multiple stages in sequence, the gas phase pipelines between the first-level absorption tower and the multiple-stage secondary absorption towers are connected in sequence, the outlet end of the pure water tank is connected to the liquid phase pipeline between the second-level absorption tower at the end, the front-end cooler is connected to the first-level absorption tower by a liquid phase pipeline, and the non-front-end cooler is connected to the second-level absorption tower of the previous stage by a liquid phase pipeline; the refrigeration group is loop-connected with the multiple coolers, and the multiple coolers are arranged in parallel.

[0007] In one possible implementation, the cooler and the secondary absorption tower of the current stage are loop-connected, the liquid phase outlet of the secondary absorption tower is connected to the hot inlet of the cooler by a pipeline, the cold outlet of the frontmost cooler is respectively connected to the liquid phase inlet of the secondary absorption tower of the current stage and the liquid phase inlet of the primary absorption tower by a pipeline, and the cold outlet of the non-frontmost cooler is respectively connected to the liquid phase inlet of the secondary absorption tower of the current stage and the liquid phase inlet of the secondary absorption tower of the previous stage by a pipeline.

[0008] In one possible implementation, the refrigeration group includes: a chilled water tank, a chilled water pump and an ice machine, the outlet end of the chilled water tank is connected to the inlet end of the ice machine by a pipeline, and the chilled water pump is arranged between the chilled water tank and the ice machine.

[0009] In one possible implementation, the hot outlet of the cooler is connected by a pipeline to the inlet end of the chilled water tank, the outlet end of the chilled water tank is connected by a pipeline to the inlet end of the chilled water pump, the outlet end of the chilled water pump is connected by a pipeline to the inlet end of the ice machine, and the outlet end of the ice machine is connected by a pipeline to the cold inlet of the cooler.

[0010] In a possible implementation, the additional absorption tower further includes: a circulation pump, each of the additional absorption towers is provided with a circulation pump, and the circulation pump is provided between the liquid phase outlet of the secondary absorption tower and the heat inlet of the cooler.

[0011] In one possible implementation, it also includes a pure water heat exchanger, wherein the outlet end of the pure water tank is connected to the hot inlet of the pure water heat exchanger by a pipeline, and the cold outlet of the pure water heat exchanger is connected to the second liquid phase inlet of the second-level absorption tower at the end by a pipeline; the pure water heat exchanger is loop-connected to the refrigeration group, the cold outlet of the refrigeration group is connected to the cold inlet of the pure water heat exchanger by a pipeline, and the hot outlet of the pure water heat exchanger is connected to the hot inlet of the refrigeration group by a pipeline.

[0012] In one possible implementation, a pure water pump is also included, which is arranged between the pure water tank and the pure water heat exchanger, the outlet end of the pure water tank is connected to the inlet end of the pure water pump by a pipeline, and the outlet end of the pure water pump is connected to the hot inlet of the pure water heat exchanger by a pipeline.

[0013] In one possible implementation, it also includes an ammonia water pump, which is arranged between the primary absorption tower and the ammonia water tank, the liquid phase outlet of the primary absorption tower is connected to the inlet end of the ammonia water pump by a pipeline, and the outlet end of the ammonia water pump is connected to the inlet end of the ammonia water tank by a pipeline.

[0014] In one possible implementation, the front-end processing group includes: a dust collector, a negative pressure buffer tank, a filter, a fan and a positive pressure buffer tank. The dust collector, the negative pressure buffer tank, the filter, the fan and the positive pressure buffer tank are connected in sequence by pipelines. The inlet end of the dust collector is suitable for connecting to a chlorine gas generating device, and the outlet end of the positive pressure buffer tank is connected to the gas phase inlet of the primary absorption tower by pipeline.

[0015] In one possible implementation, the gas phase inlet of the first-level absorption tower is set at a height lower than the liquid phase inlet of the first-level absorption tower, the gas phase outlet of the first-level absorption tower is set at the top of the first-level absorption tower, and the liquid phase outlet of the first-level absorption tower is set at the bottom of the first-level absorption tower; the gas phase inlet of the second-level absorption tower is set at a height lower than the liquid phase inlet of the second-level absorption tower, the gas phase outlet of the second-level absorption tower is set at the top of the second-level absorption tower, and the liquid phase outlet of the second-level absorption tower is set at the bottom of the second-level absorption tower.

[0016] The beneficial effects of the present application are as follows: the front-end treatment group is used to pass the ammonia gas into the primary absorption tower after front-end treatment, and then pass it into the secondary absorption tower group in sequence, so that the primary absorption tower and the secondary absorption tower are filled with ammonia gas, the pure water tank provides pure water to the second-level absorption tower at the end, and after absorbing the ammonia gas inside it, the ammonia water is passed into the cooler at the same level for cooling, and the cooled ammonia water is passed into the secondary absorption tower of the previous level to absorb ammonia gas, until the ammonia water transmitted to the first-level absorption tower to absorb the ammonia gas is passed into the ammonia water tank for storage, the secondary absorption tower and the cooler at the same level form an additional absorption tower group, and the number of additional absorption tower groups can be flexibly set according to the concentration of ammonia gas and the required concentration of ammonia water, in addition, a circulation is formed between the refrigeration group and the cooler to cool the ammonia water, and the ammonia gas is absorbed by utilizing the temperature gradient of the ammonia water, according to an ammonia tail gas multi-stage absorption device of the present application, the recovery rate of ammonia gas can be improved, and the structure of the device can be flexibly set according to the required absorption concentration to adjust the ammonia absorption effect.

[0017] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0019] Figure 1 A schematic diagram showing the main connection of the ammonia tail gas multi-stage absorption device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0020] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0021] Among them, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0024] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0025] like Figure 1 As shown, the ammonia tail gas multi-stage absorption device includes: a front-end treatment group 100, a primary absorption tower 200, an additional absorption tower group 300, a refrigeration group 400, a pure water tank 500 and an ammonia water tank 600.

[0026] The outlet end of the front-end treatment group 100 is connected to the gas phase inlet of the primary absorption tower 200 by a pipeline, the gas phase outlet of the primary absorption tower 200 is connected to the gas phase inlet of the additional absorption tower group 300 by a pipeline, and the liquid phase outlet of the primary absorption tower 200 is connected to the ammonia water tank 600 by a pipeline; the additional absorption tower group 300 includes: a secondary absorption tower 310 and a cooler 320, the liquid phase pipeline between the secondary absorption tower 310 and the cooler 320 is connected, and the number of the additional absorption tower groups 300 is one or more; when the number of the additional absorption tower groups 300 is one, the number of the secondary absorption tower 310 and the cooler 320 are both one, the gas phase outlet of the primary absorption tower 200 is connected to the gas phase inlet of the secondary absorption tower 310 by a pipeline, and the outlet end of the pure water tank 500 is connected to the secondary absorption tower 310 The liquid-phase pipelines are connected between them, and the liquid-phase pipelines between the cooler 320 and the primary absorption tower 200 are connected; when the number of the additional absorption tower groups 300 is multiple, the number of the secondary absorption towers 310 and the cooler 320 are equal and are set to multiple, and the multiple additional absorption tower groups 300 are arranged in multiple stages in sequence, the gas-phase pipelines between the primary absorption tower 200 and the multiple stages of the secondary absorption towers 310 are connected in sequence, the outlet end of the pure water tank 500 is connected to the liquid-phase pipeline between the second-stage absorption tower 310 at the end, the front-end cooler 320 is connected to the primary absorption tower 200 by a liquid-phase pipeline, and the non-front-end cooler 320 is connected to the liquid-phase pipeline of the secondary absorption tower 310 of the previous stage; the refrigeration group 400 is loop-connected to the multiple coolers 320, and the multiple coolers 320 are arranged in parallel.

[0027] The front end and back end of this application are the front end and back end of gas transmission, such as Figure 1 The left side is the front end, and the right side is the rear end. Also, a secondary absorption tower 310 and a cooler 320 form an additional absorption tower group 300, the secondary absorption tower 310 and the cooler 320 of the same level are two devices in the same additional absorption tower group 300, the previous level is two devices in the front additional absorption tower group 300, and the terminal additional absorption tower group 300 is the rearmost additional absorption tower group 300.

[0028] When the number of additional absorption tower groups 300 is one: ammonia is first processed by the dust collector 110, negative pressure buffer tank 120, filter 130, fan 140 and negative pressure buffer tank 150 of the front-end processing group 100 to ensure the continuity and purity of ammonia entering the absorption tower and enhance the absorption effect of the device. Ammonia enters from the gas phase inlet position near the bottom of the primary absorption tower 200, is discharged from the gas phase outlet at the top of the primary absorption tower 200 and enters the secondary absorption tower 310, and ammonia enters from the gas phase inlet position near the bottom of the secondary absorption tower 310. The pure water in the pure water tank 500 is sent to the pure water heat exchanger 700 through the pure water pump 510, and enters through the hot inlet of the pure water heat exchanger 700. After the pure water is cooled by heat exchange in the pure water heat exchanger 700, it is transmitted out of the pure water heat exchanger 700 through the cold outlet, and enters the secondary absorption tower 310 through the first liquid phase inlet near the top of the secondary absorption tower 310. Pure water and ammonia react in the secondary absorption tower 310. The pure water can absorb the ammonia in the secondary absorption tower 310 and generate ammonia water. The ammonia water is discharged through the liquid phase outlet at the bottom of the secondary absorption tower 310 and pumped into the cooler 320 through the circulation pump 330. The ammonia water enters through the hot inlet of the cooler 320. After the ammonia water is cooled by heat exchange in the cooler 320, it is discharged through the cold outlet of the cooler 320. If the concentration of ammonia water discharged from the cooler 320 does not meet the standard, it returns to the secondary absorption tower 310 through the second liquid phase inlet near the top of the secondary absorption tower 310, absorbs ammonia gas again, until the concentration of ammonia water discharged from the cooler 320 meets the standard, and achieves the effect of cyclic treatment; if the concentration of ammonia water discharged from the cooler 320 meets the standard, it enters the primary absorption tower 200 through the liquid phase inlet near the top of the primary absorption tower 200, absorbs the ammonia gas in the primary absorption tower 200 and then discharges it, and the ammonia water is discharged through the liquid phase outlet at the bottom of the primary absorption tower 200 and stored in the ammonia water tank 600 for standby use. The tail gas after absorption is discharged to the outside through the gas phase outlet at the top of the secondary absorption tower 310.

[0029] When there are multiple additional absorption tower groups 300: ammonia is first processed by the dust collector 110, negative pressure buffer tank 120, filter 130, fan 140 and negative pressure buffer tank 150 of the front-end processing group 100 to ensure the continuity and purity of ammonia entering the absorption tower and enhance the absorption effect of the device. Ammonia enters from the gas phase inlet position near the bottom of the primary absorption tower 200, is discharged from the gas phase outlet at the top of the primary absorption tower 200 and enters the secondary absorption tower 310. There are multiple secondary absorption towers 310, and multiple secondary absorption towers 310 are arranged in sequence, and the gas phase pipelines of multiple secondary absorption towers 310 are connected in sequence, so that ammonia can be distributed in each absorption tower. The gas phase inlet of the secondary absorption tower 310 is arranged near the bottom of the secondary absorption tower 310, and the gas phase outlet of the secondary absorption tower 310 is arranged at the top of the secondary absorption tower 310. The gas phase outlet of the secondary absorption tower 310 at the front end is connected with the gas phase inlet of the secondary absorption tower 310 at the rear end by a pipeline, wherein the gas phase outlet of the secondary absorption tower 310 at the rear end is used to discharge the tail gas after absorption. The pure water in the pure water tank 500 is sent to the pure water heat exchanger 700 through the pure water pump 510, and enters through the hot inlet of the pure water heat exchanger 700. After the pure water is cooled by heat exchange in the pure water heat exchanger 700, it is transmitted out of the pure water heat exchanger 700 through the cold outlet, and enters the second-level absorption tower 310 at the rear end through the first liquid phase inlet near the top of the secondary absorption tower 310 at the rear end. Pure water and ammonia react in the secondary absorption tower 310. Pure water can form ammonia water by absorbing ammonia gas in the secondary absorption tower 310. The ammonia water is discharged through the liquid phase outlet at the bottom of the secondary absorption tower 310 at the rear end, and is pumped into the cooler 320 at the rear end through the circulation pump 330 at the rear end. The ammonia water enters through the hot inlet of the cooler 320. After the ammonia water is cooled by heat exchange in the cooler 320, it is discharged through the cold outlet of the cooler 320. If the concentration of the ammonia water discharged from the cooler 320 does not reach the absorption effect of this stage, it returns to the secondary circulation tower of this stage through the second inlet near the top of the secondary absorption tower 310, and absorbs the ammonia gas in the tower again until the concentration of the ammonia water discharged from the cooler 320 reaches the standard, achieving the effect of circulation treatment; if the concentration of the ammonia water discharged from the cooler 320 reaches the standard of this stage, it enters the secondary absorption tower 310 through the liquid phase inlet of the previous secondary absorption tower 310 for reaction, and the discharged ammonia water is cooled by the cooler 320 of this stage and circulated again until the ammonia water is transmitted to the front-end additional absorption tower group 300, and the front-end cooler 320 outlet is respectively connected to the pipelines of the primary absorption tower 200 and the front-end secondary absorption tower 310. When the ammonia water is transmitted to the primary absorption tower 200, the ammonia gas in the primary absorption tower 200 is absorbed and discharged, and the ammonia water is discharged through the liquid phase outlet at the bottom of the primary absorption tower 200 and stored in the ammonia water tank 600 for standby use.

[0030] In one possible implementation, a loop is connected between the cooler 320 and the secondary absorption tower 310 of the same stage, a pipeline is connected between the liquid phase outlet of the secondary absorption tower 310 and the hot inlet of the cooler 320, a cold outlet of the front-end cooler 320 is respectively connected by pipeline to the liquid phase inlet of the secondary absorption tower 310 of the same stage and the liquid phase inlet of the primary absorption tower 200, and a cold outlet of the non-front-end cooler 320 is respectively connected by pipeline to the liquid phase inlet of the secondary absorption tower 310 of the same stage and the liquid phase inlet of the secondary absorption tower 310 of the previous stage.

[0031] In one possible implementation, the refrigeration group 400 includes: a chilled water tank 410, a chilled water pump 420 and an ice machine 430, the outlet end of the chilled water tank 410 is connected to the inlet end of the ice machine 430 by a pipeline, and the chilled water pump 420 is arranged between the chilled water tank 410 and the ice machine 430.

[0032] In one possible implementation, a pipeline is connected between the hot outlet of the cooler 320 and the inlet end of the chilled water tank 410, a pipeline is connected between the outlet end of the chilled water tank 410 and the inlet end of the chilled water pump 420, a pipeline is connected between the outlet end of the chilled water pump 420 and the inlet end of the ice machine 430, and a pipeline is connected between the outlet end of the ice machine 430 and the cold inlet of the cooler 320.

[0033] In a possible implementation, the additional absorption tower further includes: a circulation pump 330 . Each additional absorption tower is provided with a circulation pump 330 . The circulation pump 330 is provided between the liquid phase outlet of the secondary absorption tower 310 and the heat inlet of the cooler 320 .

[0034] In one possible implementation, it also includes a pure water heat exchanger 700, a pipeline connection between the outlet end of the pure water tank 500 and the hot inlet of the pure water heat exchanger 700, and a pipeline connection between the cold outlet of the pure water heat exchanger 700 and the second liquid phase inlet of the last secondary absorption tower 310; a loop connection between the pure water heat exchanger 700 and the refrigeration group 400, a pipeline connection between the cold outlet of the refrigeration group 400 and the cold inlet of the pure water heat exchanger 700, and a pipeline connection between the hot outlet of the pure water heat exchanger 700 and the hot inlet of the refrigeration group 400.

[0035] In one possible implementation, a pure water pump 510 is also included, which is arranged between the pure water tank 500 and the pure water heat exchanger 700. The outlet end of the pure water tank 500 is connected to the inlet end of the pure water pump 510 by a pipeline, and the outlet end of the pure water pump 510 is connected to the hot inlet of the pure water heat exchanger 700 by a pipeline.

[0036] In one possible implementation, it also includes an ammonia water pump 610, which is arranged between the primary absorption tower 200 and the ammonia water tank 600, and the liquid phase outlet of the primary absorption tower 200 is connected to the inlet end of the ammonia water pump 610 by a pipeline, and the outlet end of the ammonia water pump 610 is connected to the inlet end of the ammonia water tank 600 by a pipeline.

[0037] In a possible implementation, the front-end processing group 100 includes: a dust collector 110, a negative pressure buffer tank 120, a filter 130, a fan 140 and a negative pressure buffer tank 150, the dust collector 110, the negative pressure buffer tank 120, the filter 130, the fan 140 and the negative pressure buffer tank 150 are connected in sequence by pipelines, the inlet end of the dust collector 110 is suitable for connecting to a chlorine gas generating device, and the outlet end of the negative pressure buffer tank 150 is connected by pipeline to the gas phase inlet of the primary absorption tower 200. Among them, multiple fans 140 are single-pole pressurized and have one-to-one frequency converters and DCS control to ensure the continuous operation of the fans 140 for a long time, ensure the stability of the tail gas pipeline pressure, and set upper and lower pressure alarms at the same time, which will not cause the unit to shut down.

[0038] In one possible implementation, the gas phase inlet of the first absorption tower 200 is set at a height lower than the liquid phase inlet of the first absorption tower 200, the gas phase outlet of the first absorption tower 200 is set at the top of the first absorption tower 200, and the liquid phase outlet of the first absorption tower 200 is set at the bottom of the first absorption tower 200; the gas phase inlet of the secondary absorption tower 310 is set at a height lower than the liquid phase inlet of the secondary absorption tower 310, the gas phase outlet of the secondary absorption tower 310 is set at the top of the secondary absorption tower 310, and the liquid phase outlet of the secondary absorption tower 310 is set at the bottom of the secondary absorption tower 310.

[0039] The present application can absorb and treat the tail gas, and the heat exchange convection high-efficiency absorption tower can recover the ammonia in the tail gas, and produce ammonia water with a concentration of less than 6% through the heat exchange convection high-efficiency absorption process, while the waste gas meets the emission standards.

[0040] It should be noted that although the present application introduces an ammonia tail gas multi-stage absorption device as an example, those skilled in the art will understand that the present application should not be limited thereto. In fact, the user can flexibly set various parameters according to personal preferences and / or actual application scenarios, as long as the design is reasonable.

[0041] In this way, the front-end treatment group is used to pass the ammonia gas into the primary absorption tower after front-end treatment, and then pass it into the secondary absorption tower group in sequence, so that the primary absorption tower and the secondary absorption tower are filled with ammonia gas. The pure water tank provides pure water to the second-level absorption tower at the end. After absorbing the ammonia gas inside, the ammonia water is passed into the cooler at the same level for cooling. The cooled ammonia water is passed into the secondary absorption tower of the previous level to absorb ammonia gas, until the ammonia water that has been transmitted to the first-level absorption tower and absorbed ammonia gas is passed into the ammonia water tank for storage. The secondary absorption tower and the cooler at the same level form an additional absorption tower group, and the number of additional absorption tower groups can be flexibly set according to the concentration of ammonia gas and the required concentration of ammonia water. In addition, a circulation is formed between the refrigeration group and the cooler to cool the ammonia water, and the temperature gradient of the ammonia water is used to absorb the ammonia gas. According to an ammonia tail gas multi-stage absorption device of the present application, the recovery rate of ammonia gas can be improved, and the structure of the device can be flexibly set according to the required absorption concentration to adjust the absorption effect of ammonia gas.

[0042] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An ammonia tail gas multi-stage absorption device, characterized in that: include: Front-end treatment group, primary absorption tower, additional absorption tower group, refrigeration group, pure water tank and ammonia tank; The outlet end of the front-end treatment group is connected to the gas phase inlet of the primary absorption tower by a pipeline, the gas phase outlet of the primary absorption tower is connected to the gas phase inlet of the additional absorption tower group by a pipeline, and the liquid phase outlet of the primary absorption tower is connected to the ammonia water tank by a pipeline; The additional absorption tower group includes: a secondary absorption tower and a cooler, the secondary absorption tower and the cooler are connected by a liquid phase pipeline, and the number of the additional absorption tower group is one or more; When the number of the additional absorption tower group is one, the number of the secondary absorption tower and the cooler are both one, the gas phase outlet of the primary absorption tower is connected to the gas phase inlet of the secondary absorption tower by a pipeline, the outlet end of the pure water tank is connected to the liquid phase pipeline between the secondary absorption tower, and the liquid phase pipeline between the cooler and the primary absorption tower is connected; When the number of the additional absorption tower groups is multiple, the number of the secondary absorption towers and the coolers is equal and set to multiple, the multiple additional absorption tower groups are arranged in sequence in multiple stages, the gas phase pipelines between the primary absorption tower and the multiple stages of the secondary absorption towers are connected in sequence, the outlet end of the pure water tank is connected to the liquid phase pipeline between the second-stage absorption tower at the end, the front-end cooler is connected to the liquid phase pipeline between the primary absorption tower, and the non-front-end cooler is connected to the liquid phase pipeline between the second-stage absorption tower of the previous stage; The refrigeration group is connected to the plurality of coolers in a loop, and the plurality of coolers are arranged in parallel.

2. The ammonia tail gas multi-stage absorption device according to claim 1, characterized in that: The cooler is loop-connected to the secondary absorption tower of the current stage, the liquid phase outlet of the secondary absorption tower is connected to the hot inlet of the cooler by pipeline, the cold outlet of the frontmost cooler is respectively connected to the liquid phase inlet of the secondary absorption tower of the current stage and the liquid phase inlet of the primary absorption tower by pipeline, and the cold outlet of the non-frontmost cooler is respectively connected to the liquid phase inlet of the secondary absorption tower of the current stage and the liquid phase inlet of the secondary absorption tower of the previous stage by pipeline.

3. The ammonia tail gas multi-stage absorption device according to claim 2, characterized in that: The refrigeration group includes: a freezing water tank, a freezing water pump and an ice machine. The outlet end of the freezing water tank is connected to the inlet end of the ice machine by a pipeline, and the freezing water pump is arranged between the freezing water tank and the ice machine.

4. The ammonia tail gas multi-stage absorption device according to claim 3, characterized in that: The hot outlet of the cooler is connected to the inlet end of the chilled water tank by a pipeline, the outlet end of the chilled water tank is connected to the inlet end of the chilled water pump by a pipeline, the outlet end of the chilled water pump is connected to the inlet end of the ice machine by a pipeline, and the outlet end of the ice machine is connected to the cold inlet of the cooler by a pipeline.

5. The ammonia tail gas multi-stage absorption device according to any one of claims 1 to 4, characterized in that: The additional absorption tower further comprises: a circulation pump. Each of the additional absorption towers is provided with a circulation pump, and the circulation pump is arranged between the liquid phase outlet of the secondary absorption tower and the heat inlet of the cooler.

6. The ammonia tail gas multi-stage absorption device according to any one of claims 1 to 3, characterized in that: It also includes a pure water heat exchanger, wherein the outlet end of the pure water tank is connected to the hot inlet of the pure water heat exchanger by a pipeline, and the cold outlet of the pure water heat exchanger is connected to the second liquid phase inlet of the second-stage absorption tower at the end by a pipeline; The pure water heat exchanger is loop-connected to the refrigeration group, the cold outlet of the refrigeration group is connected to the cold inlet of the pure water heat exchanger by a pipeline, and the hot outlet of the pure water heat exchanger is connected to the hot inlet of the refrigeration group by a pipeline.

7. The ammonia tail gas multi-stage absorption device according to claim 6, characterized in that: It also includes a pure water pump, which is arranged between the pure water tank and the pure water heat exchanger. The outlet end of the pure water tank is connected to the inlet end of the pure water pump by a pipeline, and the outlet end of the pure water pump is connected to the hot inlet of the pure water heat exchanger by a pipeline.

8. The ammonia tail gas multi-stage absorption device according to any one of claims 1 to 2, characterized in that: It also includes an ammonia water pump, which is arranged between the primary absorption tower and the ammonia water tank. The liquid phase outlet of the primary absorption tower is connected to the inlet end of the ammonia water pump by a pipeline, and the outlet end of the ammonia water pump is connected to the inlet end of the ammonia water tank by a pipeline.

9. The ammonia tail gas multi-stage absorption device according to any one of claims 1 to 3, characterized in that: The front-end processing group includes: a dust collector, a negative pressure buffer tank, a filter, a fan and a positive pressure buffer tank. The dust collector, the negative pressure buffer tank, the filter, the fan and the positive pressure buffer tank are connected by pipelines in sequence. The inlet end of the dust collector is suitable for connecting to a chlorine gas generating device, and the outlet end of the positive pressure buffer tank is connected to the gas phase inlet of the primary absorption tower by pipeline.

10. The ammonia tail gas multi-stage absorption device according to any one of claims 1 to 3, characterized in that: The gas phase inlet of the primary absorption tower is arranged at a height lower than the liquid phase inlet of the primary absorption tower, the gas phase outlet of the primary absorption tower is arranged at the top of the primary absorption tower, and the liquid phase outlet of the primary absorption tower is arranged at the bottom of the primary absorption tower; The gas phase inlet of the secondary absorption tower is arranged at a height lower than the liquid phase inlet of the secondary absorption tower, the gas phase outlet of the secondary absorption tower is arranged at the top of the secondary absorption tower, and the liquid phase outlet of the secondary absorption tower is arranged at the bottom of the secondary absorption tower.

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