Ammonia tail gas treatment device

Abstract

The utility model relates to an ammonia tail gas treatment device which comprises a front-end treatment group, an ammonia removal tower, a pure water tank, a pure water heat exchanger, a refrigeration group, a cooling heat exchanger and an ammonia water tank. To-be-treated tail gas enters the ammonia removal tower after impurities are filtered out and pressure is balanced through the front-end treatment group; water in the pure water tank enters the ammonia removal tower after being subjected to heat exchange and cooling through the pure water heat exchanger, ammonia gas in the ammonia removal tower is absorbed, and ammonia water liquid absorbing the ammonia gas is discharged through a liquid phase outlet in the bottom of the ammonia removal tower; after the ammonia water is cooled by the cooling heat exchanger, if the concentration of the ammonia water does not meet the recycling standard, the ammonia water returns to the ammonia removal tower to absorb ammonia gas, and if the concentration of the ammonia water can reach the recycling standard concentration, the ammonia water enters the ammonia water tank to be stored; and the pure water heat exchanger and the cooling heat exchanger are both circularly connected with the refrigeration group and are used for cooling the liquid to establish an absorption concentration gradient, so that the absorption rate of ammonia gas is improved, and higher environmental protection requirements are met.

Description

Technical Field

[0001] The present application relates to the field of tail gas treatment, and in particular to an ammonia tail gas treatment device. Background Art

[0002] There are three commonly used methods for treating ammonia-containing waste gas: chemical method, physical method and biological method. 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 an ammonia tail gas treatment device using a physical absorption method, establishing an absorption concentration ladder in the device, improving the absorption rate of ammonia, and meeting higher environmental protection requirements.

[0005] According to one aspect of the present application, an ammonia tail gas treatment device is provided, comprising: a front-end treatment group, an ammonia removal tower, a pure water tank, a pure water heat exchanger, a refrigeration group, a cooling heat exchanger and an ammonia water tank.

[0006] The outlet end of the front-end treatment group is connected to the first inlet pipeline of the ammonia removal tower; the water outlet of the pure water tank is connected to the first inlet pipeline of the pure water heat exchanger, and the first outlet of the pure water heat exchanger is connected to the second inlet pipeline of the ammonia removal tower; a liquid phase outlet is provided at the bottom of the ammonia removal tower, the liquid phase outlet of the ammonia removal tower is connected to the first inlet pipeline of the cooling heat exchanger, and the first outlet of the cooling heat exchanger is respectively connected to the third inlet of the ammonia removal tower and the ammonia water tank pipeline; the second outlet of the cooling heat exchanger is connected to the inlet end pipeline of the refrigeration group, and the outlet end of the refrigeration group is connected to the second inlet pipeline of the cooling heat exchanger; the second outlet of the pure water heat exchanger is connected to the inlet end pipeline of the refrigeration group, and the outlet end of the refrigeration group is connected to the second inlet pipeline of the pure water heat exchanger; a gas phase outlet is provided at the top of the ammonia removal tower, and the gas phase outlet of the ammonia removal tower is suitable for connecting to the outdoors.

[0007] In one possible implementation, the second inlet of the ammonia removal tower is set at an equal height to the third inlet of the ammonia removal tower, and the second inlet of the ammonia removal tower is set at a higher height than the first inlet of the ammonia removal tower.

[0008] In one possible implementation, the front-end processing group includes: a negative pressure buffer tank, a filter, a fan and a positive pressure buffer tank; the exhaust gas is suitable for entering through the inlet end of the negative pressure buffer tank, the outlet end of the negative pressure buffer tank is connected to the inlet end pipeline of the filter, the outlet end of the filter is connected to the inlet end pipeline of the fan, the outlet end of the fan is connected to the inlet end pipeline of the positive pressure buffer tank, and the outlet end of the positive pressure buffer tank is connected to the first inlet pipeline of the ammonia removal tower.

[0009] In one possible implementation, the refrigeration group includes: a chilled water tank and an ice machine, wherein the outlet end of the chilled water tank is connected to the inlet end pipeline of the ice machine; the second outlet of the cooling heat exchanger is connected to the inlet end pipeline of the chilled water tank, and the outlet end of the ice machine is connected to the second inlet pipeline of the cooling heat exchanger; the second outlet of the pure water heat exchanger is connected to the inlet end pipeline of the chilled water tank, and the outlet end of the ice machine is connected to the second inlet pipeline of the pure water heat exchanger.

[0010] In a possible implementation, a chilled water pump is provided between the chilled water tank and the ice machine.

[0011] In one possible implementation, a pure water pump is provided between the water outlet of the pure water tank and the pure water heat exchanger.

[0012] In one possible implementation, a first circulation pump is provided between the liquid phase outlet of the ammonia removal tower and the cooling heat exchanger.

[0013] In a possible implementation, a second circulation pump is provided between the first outlet of the cooling heat exchanger and the ammonia water tank.

[0014] In one possible implementation, a drainage pump is provided at the outlet end of the ammonia water tank.

[0015] The beneficial effects of the present application are as follows: the tail gas to be treated is processed by the front-end processing group, and the impurities in the tail gas are filtered out and the pressure is balanced before entering the ammonia removal tower; the water in the pure water tank enters the ammonia removal tower after heat exchange and cooling in the pure water heat exchanger, and absorbs the ammonia in the tail gas in the ammonia removal tower, and the ammonia liquid that has absorbed the ammonia is discharged through the liquid phase outlet at the bottom of the ammonia removal tower; after being cooled by the cooling heat exchanger, if the ammonia concentration does not meet the recycling and reuse standards, it returns to the ammonia removal tower to absorb ammonia again, and if the ammonia concentration can reach the recycling standard concentration, it enters the ammonia tank for storage and standby; wherein, the pure water heat exchanger and the cooling heat exchanger are both connected to the refrigeration group in a loop, which is used to cool the liquid to establish an absorption concentration gradient. According to an ammonia tail gas treatment device of the present application, a physical absorption method is used to establish an absorption concentration ladder in the device, improve the absorption rate of ammonia, and meet higher environmental protection requirements.

[0016] 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

[0017] 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.

[0018] Figure 1 A connection diagram of an ammonia tail gas treatment device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] As shown in the figure, the ammonia tail gas treatment device includes: a front-end treatment group 100, an ammonia removal tower 200, a pure water tank 300, a pure water heat exchanger 400, a refrigeration group 500, a cooling heat exchanger 600 and an ammonia water tank 700.

[0025] The outlet end of the front-end treatment group 100 is connected to the first inlet pipeline of the ammonia removal tower 200; the water outlet of the pure water tank 300 is connected to the first inlet pipeline of the pure water heat exchanger 400, and the first outlet of the pure water heat exchanger 400 is connected to the second inlet pipeline of the ammonia removal tower 200; the bottom of the ammonia removal tower 200 is provided with a liquid phase outlet, and the liquid phase outlet of the ammonia removal tower 200 is connected to the first inlet pipeline of the cooling heat exchanger 600, and the first outlet of the cooling heat exchanger 600 is respectively connected to the third inlet and The ammonia water tank 700 is connected by pipeline; the second outlet of the cooling heat exchanger 600 is connected by pipeline to the inlet end of the refrigeration group 500, and the outlet end of the refrigeration group 500 is connected by pipeline to the second inlet end of the cooling heat exchanger 600; the second outlet of the pure water heat exchanger 400 is connected by pipeline to the inlet end of the refrigeration group 500, and the outlet end of the refrigeration group 500 is connected by pipeline to the second inlet end of the pure water heat exchanger 400; a gas phase outlet is provided at the top of the ammonia removal tower 200, and the gas phase outlet of the ammonia removal tower 200 is suitable for connecting to the outdoors.

[0026] After the MOCVD tail gas absorbs most of the ammonia through the ammonia recovery system, the residual ammonia in the mixed gas is denitrified again through the ammonia tail gas treatment device of the present application.

[0027] The exhaust gas first reduces the gas pressure through the negative pressure buffer tank 110 to form a negative pressure environment to achieve further transportation of the exhaust gas. Secondly, the impurities in the gas are filtered out by the filter 120, and then the transportation is accelerated by the fan 130. Finally, the positive pressure buffer tank 140 is used to ensure continuous and stable supply of gas to the ammonia removal tower 200.

[0028] The exhaust gas after pre-treatment enters the ammonia removal tower 200 through the first inlet of the ammonia removal tower 200, the water in the pure water tank 300 is pressurized by the pure water pump 310 and enters the pure water heat exchanger 400 for cooling, the cooled pure water enters the ammonia removal tower 200 through the second inlet, and absorbs the ammonia in the ammonia removal tower 200, the exhaust gas after absorption is discharged through the gas phase outlet at the top of the ammonia removal tower 200, and the ammonia water is discharged through the liquid phase outlet at the bottom of the ammonia removal tower 200.

[0029] The ammonia water is pressurized by the first circulation pump 210 and enters the cooling heat exchanger 600 for cooling. If the ammonia water after cooling reaches the concentration of ammonia water that can be recycled and reused, it is pressurized by the second circulation pump 710 and enters the ammonia water tank 700 for storage and reuse. If the ammonia water after cooling does not reach the concentration of ammonia water that can be recycled and reused, it enters the ammonia removal tower 200 again through the third inlet of the ammonia removal tower 200 to absorb ammonia in the exhaust gas.

[0030] The pure water heat exchanger 400 and the cooling heat exchanger 600 both cool down by circulating with the refrigeration group 500. The second outlet of the pure water heat exchanger 400 is connected to the inlet pipeline of the frozen water tank 510, and the outlet of the frozen water tank 510 is provided with a frozen water pump 530 for pressurization, and the pressurized water enters the inlet of the ice machine 520, and the outlet of the ice machine 520 is connected to the second inlet pipeline of the pure water heat exchanger 400. The second outlet of the cooling heat exchanger 600 is connected to the inlet pipeline of the frozen water tank 510, and the outlet of the frozen water tank 510 is provided with a frozen water pump 530 for pressurization, and the pressurized water enters the inlet of the ice machine 520, and the outlet of the ice machine 520 is connected to the second inlet pipeline of the cooling heat exchanger 600.

[0031] In one possible implementation, the second inlet of the ammonia removal tower 200 is set at a height equal to the third inlet of the ammonia removal tower 200, and the second inlet of the ammonia removal tower 200 is set at a height higher than the first inlet of the ammonia removal tower 200.

[0032] The second and third inlets of the ammonia removal tower 200 are both liquid phase inlets, and the first inlet of the ammonia removal tower 200 is a gas phase inlet. Therefore, the second and third inlets of the ammonia removal tower 200 are set at higher heights than the first inlet, which can improve the absorption rate of ammonia.

[0033] In one possible implementation, the front-end treatment group 100 includes: a negative pressure buffer tank 110, a filter 120, a fan 130 and a positive pressure buffer tank 140; the exhaust gas is suitable for entering through the inlet end of the negative pressure buffer tank 110, the outlet end of the negative pressure buffer tank 110 is connected to the inlet end pipeline of the filter 120, the outlet end of the filter 120 is connected to the inlet end pipeline of the fan 130, the outlet end of the fan 130 is connected to the inlet end pipeline of the positive pressure buffer tank 140, and the outlet end of the positive pressure buffer tank 140 is connected to the first inlet pipeline of the ammonia removal tower 200.

[0034] In one possible implementation, the refrigeration group 500 includes: a chilled water tank 510 and an ice machine 520, wherein the outlet end of the chilled water tank 510 is connected to the inlet end of the ice machine 520 by a pipeline; the second outlet of the cooling heat exchanger 600 is connected to the inlet end of the chilled water tank 510 by a pipeline, and the outlet end of the ice machine 520 is connected to the second inlet end of the cooling heat exchanger 600 by a pipeline; the second outlet of the pure water heat exchanger 400 is connected to the inlet end of the chilled water tank 510 by a pipeline, and the outlet end of the ice machine 520 is connected to the second inlet end of the pure water heat exchanger 400 by a pipeline.

[0035] In a possible implementation, a chilled water pump 530 is disposed between the chilled water tank 510 and the ice machine 520 .

[0036] In a possible implementation, a pure water pump 310 is provided between the water outlet of the pure water tank 300 and the pure water heat exchanger 400 .

[0037] In a possible implementation, a first circulation pump 210 is provided between the liquid phase outlet of the ammonia removal tower 200 and the cooling heat exchanger 600 .

[0038] In a possible implementation, a second circulation pump 710 is provided between the first outlet of the cooling heat exchanger 600 and the ammonia water tank 700 .

[0039] In a possible implementation, a drainage pump 720 is provided at the outlet end of the ammonia water tank 700 .

[0040] The present application adopts a packed deammonification tower to reduce the ammonia content in the tail gas to below 300ppm, and at the same time produces 3% to 5% ammonia water, which is returned to the ammonia recovery system for water replenishment to produce high-concentration ammonia water for export, thereby recycling resources without producing by-products.

[0041] It should be noted that although an ammonia tail gas treatment device is introduced as an example in this application, those skilled in the art will understand that this application should not be limited thereto. In fact, users can flexibly set various parameters according to personal preferences and / or actual application scenarios, as long as the design is reasonable.

[0042] In this way, the tail gas to be treated is processed by the front-end processing group, and the impurities in the tail gas are filtered out and the pressure is balanced before entering the ammonia removal tower; the water in the pure water tank enters the ammonia removal tower after heat exchange and cooling in the pure water heat exchanger, and absorbs the ammonia in the tail gas in the ammonia removal tower. The ammonia liquid that has absorbed the ammonia is discharged through the liquid phase outlet at the bottom of the ammonia removal tower; after being cooled by the cooling heat exchanger, if the ammonia concentration does not meet the recycling and reuse standards, it returns to the ammonia removal tower to absorb ammonia again. If the ammonia concentration can reach the recycling standard concentration, it enters the ammonia tank for storage and standby; wherein the pure water heat exchanger and the cooling heat exchanger are both connected to the refrigeration group in a loop, which is used to cool the liquid to establish an absorption concentration gradient. According to an ammonia tail gas treatment device of the present application, a physical absorption method is used to establish an absorption concentration ladder in the device, improve the absorption rate of ammonia, and can recycle the absorbed ammonia to meet higher environmental protection requirements.

[0043] 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 treatment device, characterized in that: include: Front-end treatment group, ammonia removal tower, pure water tank, pure water heat exchanger, refrigeration group, cooling heat exchanger and ammonia water tank; The outlet end of the front-end processing group is connected to the first inlet pipeline of the ammonia removal tower; The water outlet of the pure water tank is connected to the first inlet pipeline of the pure water heat exchanger, and the first outlet of the pure water heat exchanger is connected to the second inlet pipeline of the ammonia removal tower; A liquid phase outlet is provided at the bottom of the ammonia removal tower, the liquid phase outlet of the ammonia removal tower is connected to the first inlet pipeline of the cooling heat exchanger, and the first outlet of the cooling heat exchanger is respectively connected to the third inlet of the ammonia removal tower and the ammonia water tank pipeline; The second outlet of the cooling heat exchanger is connected to the inlet pipeline of the refrigeration group, and the outlet of the refrigeration group is connected to the second inlet pipeline of the cooling heat exchanger; The second outlet of the pure water heat exchanger is connected to the inlet pipeline of the refrigeration group, and the outlet of the refrigeration group is connected to the second inlet pipeline of the pure water heat exchanger; A gas phase outlet is provided on the top of the ammonia removal tower, and the gas phase outlet of the ammonia removal tower is suitable for being connected to the outside.

2. The ammonia tail gas treatment device according to claim 1, characterized in that: The setting height of the second inlet of the ammonia removal tower is equal to the setting height of the third inlet of the ammonia removal tower, and the setting height of the second inlet of the ammonia removal tower is higher than the setting height of the first inlet of the ammonia removal tower.

3. The ammonia tail gas treatment device according to any one of claims 1 to 2, characterized in that: The front-end processing group includes: a negative pressure buffer tank, a filter, a fan and a positive pressure buffer tank; The exhaust gas is suitable for entering through the inlet end of the negative pressure buffer tank, the outlet end of the negative pressure buffer tank is connected to the inlet end pipeline of the filter, the outlet end of the filter is connected to the inlet end pipeline of the fan, the outlet end of the fan is connected to the inlet end pipeline of the positive pressure buffer tank, and the outlet end of the positive pressure buffer tank is connected to the first inlet pipeline of the ammonia removal tower.

4. The ammonia tail gas treatment device according to any one of claims 1 to 2, characterized in that: The refrigeration group includes: a freezing water tank and an ice machine, wherein the outlet end of the freezing water tank is connected to the inlet end of the ice machine through a pipeline; The second outlet of the cooling heat exchanger is connected to the inlet end pipeline of the freezing water tank, and the outlet end of the ice machine is connected to the second inlet pipeline of the cooling heat exchanger; The second outlet of the pure water heat exchanger is connected to the inlet pipeline of the freezing water tank, and the outlet of the ice machine is connected to the second inlet pipeline of the pure water heat exchanger.

5. The ammonia tail gas treatment device according to claim 4, characterized in that: A freezing water pump is arranged between the freezing water tank and the ice machine.

6. The ammonia tail gas treatment device according to any one of claims 1-2, characterized in that: A pure water pump is arranged between the water outlet of the pure water tank and the pure water heat exchanger.

7. The ammonia tail gas treatment device according to any one of claims 1-2, characterized in that: A first circulation pump is arranged between the liquid phase outlet of the ammonia removal tower and the cooling heat exchanger.

8. The ammonia tail gas treatment device according to any one of claims 1 to 2, characterized in that: A second circulation pump is provided between the first outlet of the cooling heat exchanger and the ammonia water tank.

9. The ammonia tail gas treatment device according to any one of claims 1-2, characterized in that: A drainage pump is provided at the outlet end of the ammonia water tank.

Images