Ammonia gas absorption circulating system and method

Abstract

The invention relates to an ammonia gas absorption and circulation system, which is used for carrying out ammonia gas absorption and circulation on waste gas generated by an industrial system, and comprises an ammonia water storage tank for storing ammonia water; the first ammonia gas recovery system is respectively connected with the ammonia water storage tank and the industrial system; the second ammonia gas recovery system is connected with the first ammonia gas recovery system; and the third ammonia gas recovery system is connected with the second ammonia gas recovery system. According to the ammonia absorption system and method, the ammonia can be efficiently absorbed, the concentration of the ammonia in waste gas is reduced to be 20 mg / m < 3 > or below, meanwhile, the recycled ammonia is reused in the project production process, and the production cost can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of ammonia treatment, and in particular to an ammonia absorption circulation system and method. Background Art

[0002] Ammonia is an important raw material in industry. It is a colorless, toxic, reactive, corrosive gas with a strong odor.

[0003] Ammonia can strongly irritate the mucous membranes of humans and animals, such as the eyes and respiratory tract, and can cause serious harm to people in a short period of time under high concentration conditions. Ammonia is used or produced in the chemical industry, such as pharmaceuticals, petrochemicals, food processing, wastewater treatment, sludge treatment, and fertilizer manufacturing.

[0004] In the process of processing and production in such industries, if the emission of ammonia tail gas is not strictly controlled, or the recovery and treatment is not timely and thorough, part of the ammonia tail gas will be released, which will have an adverse impact on the production area and the surrounding environment. This will not only cause physical harm to the operators, but also pose certain risks of fire and flash explosion. Moreover, the emission of ammonia tail gas into the environment will also cause a series of problems such as eutrophication of water bodies and air pollution.

[0005] Traditional ammonia stripping systems require large engineering investments, high energy consumption, high operating costs, and average treatment effects. Therefore, how to propose a strategy to timely and thoroughly recover ammonia tail gas and control the emission of ammonia tail gas in chemical production has become an urgent problem to be solved. Summary of the invention

[0006] The object of the present invention is to provide an ammonia absorption circulation system and method, which has the advantage of efficiently absorbing ammonia.

[0007] To achieve the above-mentioned purpose, the present invention provides an ammonia absorption circulation system, the circulation system absorbs and circulates the waste gas generated by the industrial system, and the circulation system comprises: an ammonia water storage tank, which is used to store ammonia water; a first ammonia recovery system, which is connected to the ammonia water storage tank and the industrial system respectively; the first ammonia recovery system receives the waste gas from the industrial system, condenses and falls a film on the waste gas, and passes the condensed and fallen film waste gas into water to generate ammonia water, extracts the ammonia water therein and transmits it to the ammonia water storage tank; the second ammonia recovery system is connected to the first ammonia recovery system, receives the waste gas from the first ammonia recovery system, and the waste gas is condensed and falls a film on the waste gas, and the waste gas is passed into water to generate ammonia water, and the ammonia water therein is extracted and transmitted to the ammonia water storage tank; the second ammonia recovery system is connected to the first ammonia recovery system, receives the waste gas from the first ammonia recovery system, and the waste gas is condensed and falls a film on the waste gas ... The ammonia recovery system receives the treated waste gas from the second ammonia recovery system, enriches the ammonia in the waste gas to generate ammonia water, extracts the ammonia water and transmits it to the first ammonia recovery system, and then the first ammonia recovery system transmits the ammonia water to the ammonia water storage tank; the third ammonia recovery system is connected to the second ammonia recovery system, receives the treated waste gas from the second ammonia recovery system, enriches the ammonia in the waste gas to generate ammonia water, extracts the ammonia water and transmits it to the second ammonia recovery system, and then the second ammonia recovery system transmits it to the first ammonia recovery system, and then the first ammonia recovery system transmits the ammonia water to the ammonia water storage tank.

[0008] Preferably, the circulation system includes: an exhaust gas post-processor connected to the third ammonia recovery system, receiving the treated exhaust gas from the third ammonia recovery system, and neutralizing the treated exhaust gas.

[0009] Preferably, the first ammonia recovery system includes: a condenser and film falling device, which is connected to the industrial system, receives the waste gas from the industrial system, and condenses it to generate condensed gaseous ammonia; a dilute ammonia water tank, which is respectively connected to the condenser and film falling device and the second ammonia recovery system; water is stored in the dilute ammonia water tank, which receives the gaseous ammonia from the condenser and film falling device and generates ammonia water; the dilute ammonia water tank transmits the treated waste gas to the second ammonia recovery system; a first transfer tank, which is respectively connected to the dilute ammonia water tank and the ammonia water storage tank, receives the ammonia water from the dilute ammonia water tank, and transmits it to the ammonia water storage tank.

[0010] Preferably, the second ammonia recovery system includes: an ammonia absorption tower, which is connected to the condensation and falling film device, receives the treated waste gas from the condensation and falling film device, extracts ammonia from it, generates ammonia water, and transmits the treated waste gas to the third ammonia recovery system; a second transfer tank, which is respectively connected to the ammonia absorption tower and the first transfer tank, receives the ammonia water from the ammonia absorption tower, transmits it to the first transfer tank, and then transmits it to the ammonia water storage tank from the first transfer tank.

[0011] Preferably, the third ammonia recovery system includes: a multi-stage absorption tower, which is respectively connected to the ammonia absorption tower and the exhaust gas post-processor, receives the treated exhaust gas from the ammonia absorption tower, extracts ammonia from it, generates ammonia water, and transmits the treated exhaust gas to the exhaust gas post-processor; a third transfer tank, which is respectively connected to the multi-stage absorption tower and the second transfer tank, receives the ammonia water from the multi-stage absorption tower, transmits it to the second transfer tank, transmits it from the second transfer tank to the first transfer tank, and then transmits it from the first transfer tank to the ammonia water storage tank.

[0012] Preferably, the dilute ammonia water tank is connected to the first transfer tank by a cooling pipeline; the ammonia absorption tower is connected to the second transfer tank by a cooling pipeline; and the multi-stage absorption tower is connected to the third transfer tank by a cooling pipeline.

[0013] Preferably, the multi-stage absorption tower includes: a primary absorption tower, which is respectively connected to the ammonia absorption tower and the third transfer tank, is provided with a condenser, receives the treated waste gas from the ammonia absorption tower, extracts ammonia from it, and generates ammonia water; a secondary absorption tower, which is connected to the primary absorption tower, is provided with a condenser, receives the treated waste gas from the primary absorption tower, extracts ammonia from it, and generates ammonia water; a tertiary absorption tower, which is connected to the secondary absorption tower, receives the treated waste gas from the secondary absorption tower, and is provided with corresponding fillers for absorbing ammonia; a quaternary absorption tower, which is respectively connected to the tertiary absorption tower and the waste gas post-processor, and is provided with corresponding fillers for absorbing ammonia.

[0014] An ammonia absorption circulation method is implemented by the aforementioned ammonia absorption circulation system, and the method comprises: step S1, condensing and falling film treating the waste gas and passing it into water for ammonia extraction treatment to generate ammonia water and waste gas after primary treatment; the condensation temperature is 30°C~38°C, and the pressure is 0.16MPa~0.18MPa; step S2, using fillers to enrich ammonia in the waste gas after primary treatment, and adding absorption liquid above the fillers to wash the fillers to generate ammonia water and waste gas after secondary treatment, and the fillers are metal ring saddles; step S3, multi-stage treating the waste gas after secondary treatment to generate ammonia water and waste gas after tertiary treatment; step S4, performing waste gas post-treatment on the waste gas after tertiary treatment; step S5, ending the process.

[0015] Preferably, the step S3 includes: step S31, condensing the waste gas after secondary treatment, the condensation temperature is 30C°~50C°, the pressure is 0.16MPa~0.18MPa, to generate ammonia water; step S32, condensing the gas, the condensation temperature is 30C°~40C°, the pressure is 0.17MPa, to generate ammonia water; step S33, enriching the ammonia gas through a metal ring matrix saddle filler; step S34, adding absorption liquid above the metal ring matrix saddle filler, enriching the gas through a Venturi jet system, to generate ammonia water and the waste gas after tertiary treatment.

[0016] Preferably, the step S4 comprises: introducing 5% to 10% dilute sulfuric acid, dilute hydrochloric acid or dilute phosphoric acid into the waste gas after the tertiary treatment.

[0017] In summary, compared with the prior art, the ammonia absorption circulation system and method provided by the present invention have the following advantages:

[0018] First, the ammonia absorption system and method used in the present invention can efficiently absorb ammonia and reduce the ammonia concentration in the exhaust gas to 20 mg / m 3 Next, the recovered ammonia is reused in the project production process, which can effectively reduce production costs.

[0019] Second, the present invention is easy to operate, can be circulated multiple times, and has excellent effects of treating waste gas and protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of an ammonia absorption circulation system proposed by the present invention.

[0021] Figure 2 It is a schematic diagram of the structure of the multi-stage absorption tower in the present invention.

[0022] Figure 3 The present invention provides an ammonia absorption circulation system, which adopts a plurality of second ammonia recovery systems.

[0023] Figure 4 The present invention is a flow chart of an ammonia absorption circulation method.

[0024] Reference numerals:

[0025] 1-ammonia storage tank, 2-waste gas post-processor, 3-industrial system, 4-first ammonia recovery system, 5-second ammonia recovery system, 6-third ammonia recovery system, 7-condensation film falling device, 8-first transfer tank, 9-cooling pipeline, 10-ammonia absorption tower, 11-second transfer tank, 12-multi-stage absorption tower, 13-third transfer tank, 121-first absorption tower, 122-secondary absorption tower, 123-third absorption tower, 124-fourth-stage absorption tower. DETAILED DESCRIPTION

[0026] The following will be combined with the attached embodiment of the present invention Figures 1 to 4 , the technical solutions, structural features, objectives achieved and effects in the embodiments of the present invention are described in detail.

[0027] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0028] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only the elements explicitly listed, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0029] The present invention proposes an ammonia absorption circulation system. A large amount of waste gas is generated during the production process in the industrial system. The absorption circulation system receives the waste gas from the industrial system and processes and recovers the ammonia in the waste gas generated during industrial operation. The present invention can efficiently absorb the ammonia generated by the industrial system and reduce the concentration of ammonia to 20mg / m 3 Next, the recovered ammonia gas is converted into ammonia water, which is recycled in the project production process, effectively reducing production costs.

[0030] like Figure 1 As shown, the circulatory system includes:

[0031] The ammonia water storage tank 1 is used to store ammonia water. Since ammonia water is volatile, the sealing performance of the ammonia water storage tank 1 should be paid attention to in specific applications.

[0032] The first ammonia recovery system 4 is connected to the ammonia water storage tank 1 and the industrial system 3 respectively; the first ammonia recovery system 4 receives the waste gas from the industrial system 3, condenses and forms a film on the waste gas, and passes the condensed and formed waste gas into water to generate ammonia water, extracts the ammonia water therein and transmits it to the ammonia water storage tank 1;

[0033] The second ammonia recovery system 5 is connected to the first ammonia recovery system 4, receives the treated waste gas from the first ammonia recovery system 4, enriches the ammonia in the waste gas to generate ammonia water, extracts the ammonia water therein and transmits it to the first ammonia recovery system 4, and then the first ammonia recovery system 4 transmits the ammonia water to the ammonia water storage tank 1;

[0034] The third ammonia recovery system 6 is connected to the second ammonia recovery system 5, receives the treated exhaust gas from the second ammonia recovery system 5, enriches the ammonia in the exhaust gas to generate ammonia water, extracts the ammonia water and transmits it to the second ammonia recovery system 5, which is then transmitted to the first ammonia recovery system 4 by the second ammonia recovery system 5, and then the ammonia water is transmitted to the ammonia water storage tank 1 by the first ammonia recovery system 4.

[0035] The above-mentioned three-level ammonia recovery system is used to treat the waste gas generated by the industrial system 3 step by step, achieving a high recovery rate of ammonia and ensuring that under normal circumstances, ammonia water with a concentration of 15-25% is produced.

[0036] In addition, in a preferred embodiment, in order to ensure that the treated waste gas output by the third ammonia recovery system 6 meets the standards after harmlessness, the circulation system also includes: a waste gas post-processor 2, which is connected to the third ammonia recovery system 6, receives the treated waste gas from the third ammonia recovery system 6, and neutralizes it as needed; for example, when the treated waste gas is too acidic, an alkaline substance is placed in the waste gas post-processor 2 for treatment; or if the treated waste gas also contains toxic substances, further harmless treatment is performed as needed; or an acidification tank is set in the waste gas post-processor 2 to further intercept ammonia in the waste gas, and so on, which will not be elaborated here.

[0037] The first ammonia recovery system 4 , the second ammonia recovery system 5 and the third ammonia recovery system 6 will be described in detail below.

[0038] (I) The first ammonia recovery system 4

[0039] like Figure 1 As shown, the first ammonia recovery system 4 is directly connected to the industrial system 3. Therefore, in some cases, since the first ammonia recovery system 4 directly receives the waste gas generated by the industrial system 3, the waste gas often has a high temperature characteristic.

[0040] In order to ensure smoother treatment of the waste gas, the first ammonia recovery system 4 includes:

[0041] The condenser and film-falling device 7 is connected to the industrial system 3, receives the exhaust gas from the industrial system 3, and condenses it. The condenser and film-falling device 7 is a heat exchange device, which is mainly used to transfer the heat in the high-temperature gas to the cooling medium. When the high-temperature gas enters the condenser and film-falling device 7, the water vapor in the gas begins to cool down through the heat transfer effect of the cooling medium; subsequently, the condensed gaseous ammonia (still maintaining the properties of the gaseous state) will be introduced into the water;

[0042] The dilute ammonia water tank is connected to the condensation and film falling device 7 and the second ammonia recovery system 5 (the ammonia absorption tower 10 described later) respectively. Water is stored in the dilute ammonia water tank. After the condensation and film falling device 7 condenses and falls the ammonia gas, the gaseous ammonia gas is received and the dilute ammonia water tank generates ammonia water. At the same time, the dilute ammonia water tank transmits the treated waste gas to the second ammonia recovery system 5 (the ammonia absorption tower 10 described later); this is equivalent to the dilute ammonia water tank transmitting the treated waste gas to the second ammonia recovery system 5 after gas-liquid separation.

[0043] The first transfer tank 8 is connected to the dilute ammonia water tank and the ammonia water storage tank 1 respectively, receives the ammonia water from the dilute ammonia water tank, and transmits it to the ammonia water storage tank 1 .

[0044] In a preferred embodiment, in order to further ensure the stability of ammonia water from the dilute ammonia water tank to the first transfer tank 8, the dilute ammonia water tank and the first transfer tank 8 are connected by a cooling pipeline 9, and the ammonia water generated by the dilute ammonia water tank enters the first transfer tank 8 through the cooling pipeline 9, further ensuring that the ammonia water does not volatilize during the transmission process.

[0045] (II) Second ammonia recovery system 5

[0046] like Figure 1 As shown, the second ammonia recovery system 5 is connected to the dilute ammonia water tank, the first transfer tank 8 and the third ammonia recovery system 6 respectively, and the waste gas is treated and the ammonia water is transferred according to the mode as described above.

[0047] Specifically, the second ammonia recovery system 5 comprises:

[0048] The ammonia absorption tower 10 is connected to the dilute ammonia water tank, receives the treated waste gas from the dilute ammonia water tank, extracts ammonia from the waste gas, generates ammonia water, and transmits the treated waste gas to the third ammonia recovery system 6. Specifically, the ammonia absorption tower 10 is provided with corresponding fillers for absorbing ammonia, and the fillers are flushed by regularly pouring absorption liquid from above the fillers to achieve ammonia enrichment.

[0049] The second transfer tank 11 is connected to the ammonia absorption tower 10 and the first transfer tank 8 respectively, receives the ammonia water from the ammonia absorption tower 10, transfers it to the first transfer tank 8, and then transfers it to the ammonia water storage tank 1 from the first transfer tank 8.

[0050] In a preferred embodiment, in order to further ensure the stability of ammonia water from the ammonia absorption tower 10 to the second transfer tank 11, the ammonia absorption tower 10 and the second transfer tank 11 are connected by a cooling pipeline 9, and the ammonia water generated by the ammonia absorption tower 10 enters the second transfer tank 11 through the cooling pipeline 9, further ensuring that the ammonia water does not volatilize during the transmission process.

[0051] (III) The third ammonia recovery system 6

[0052] like Figure 1 and Figure 2 As shown, the third ammonia recovery system 6 is connected to the ammonia absorption tower 10 and the second transfer tank 11 respectively, and the waste gas is treated and the ammonia water is transferred according to the mode as described above.

[0053] Specifically, the third ammonia recovery system 6 comprises:

[0054] The multi-stage absorption tower 12 is connected to the ammonia absorption tower 10 and the exhaust gas post-processor 2 respectively, receives the treated exhaust gas from the ammonia absorption tower 10, produces ammonia water, extracts ammonia, and transmits the treated exhaust gas to the exhaust gas post-processor 2.

[0055] The third transfer tank 13 is connected to the multi-stage absorption tower 12 and the second transfer tank 11 respectively, receives the ammonia water from the multi-stage absorption tower 12, transfers it to the second transfer tank 11, transfers it to the first transfer tank 8 from the second transfer tank 11, and then transfers it to the ammonia water storage tank 1 from the first transfer tank 8.

[0056] In a preferred embodiment, in order to further ensure the stability of ammonia water from the multi-stage absorption tower 12 to the third transfer tank 13, the multi-stage absorption tower 12 and the third transfer tank 13 are connected by a cooling pipeline 9, and the ammonia water generated by the multi-stage absorption tower 12 enters the third transfer tank 13 through the cooling pipeline 9, further ensuring that the ammonia water does not volatilize during the transmission process.

[0057] Furthermore, if Figure 2 As shown, a specific embodiment of a multi-stage absorption tower 12 is introduced below. In a specific embodiment, the multi-stage absorption tower 12 includes:

[0058] The primary absorption tower 121 is connected to the ammonia absorption tower 10 and the third transfer tank 13 respectively, and is provided with a condenser to receive the treated waste gas from the ammonia absorption tower 10 and extract ammonia from it. The principle is as described above and will not be elaborated here;

[0059] The secondary absorption tower 122 is connected to the primary absorption tower 121 and is provided with a condenser. Since the gas moves upward, the secondary absorption tower 122 receives the treated waste gas from the primary absorption tower 121 and extracts ammonia from the waste gas. The principle is as described above and will not be elaborated here.

[0060] A tertiary absorption tower 123, which is connected to the secondary absorption tower 122, receives the treated exhaust gas from the secondary absorption tower 122; a corresponding filler for absorbing ammonia is arranged inside the tertiary absorption tower 123, and the filler is flushed by regularly showering the absorption liquid from above the filler (for example, from above the quaternary absorption tower 124), thereby achieving the enrichment of ammonia;

[0061] The fourth-stage absorption tower 124 is connected to the third-stage absorption tower 123 and the exhaust gas post-processor 2 respectively, and is provided with corresponding fillers for absorbing ammonia. By regularly pouring absorption liquid from above the fillers, the fillers are flushed to achieve ammonia enrichment;

[0062] The generated ammonia water will move downward due to gravity and then reach the third transfer tank 13 to achieve the collection of the ammonia water.

[0063] The above is a detailed introduction of the three ammonia recovery systems, in order to further optimize the technical effect of the entire circulation system;

[0064] In a preferred embodiment, the connection of the various components adopts a Venturi jet system. The jet principle is the phenomenon that when a fluid passes through a narrowing channel or nozzle, the velocity increases and the pressure decreases. Specifically, when a high-speed fluid enters the ejector through a nozzle, the fluid velocity increases rapidly due to the small channel of the nozzle, forming a high-speed jet. At the same time, the high-speed jet mixes with the ambient gas, and the gas velocity also increases. The absorption of ammonia is enhanced, while avoiding environmental pollution caused by the escape of ammonia from the system. For example, the four-stage absorption tower 124 receives the treated exhaust gas from the three-stage absorption tower 123, enriches the ammonia based on the jet principle, and transmits the treated exhaust gas to the exhaust gas after-processor 2.

[0065] In a preferred embodiment, the entire system is in a slightly negative pressure environment; because in a slightly negative pressure environment, the boiling point of the ammonia solution is reduced, making it easier to extract. By adjusting the negative pressure, the evaporation rate and temperature of the ammonia can be controlled to achieve efficient extraction.

[0066] At the same time, a multi-stage countercurrent microbubble absorption process is adopted in the ammonia absorption tower 10 and the multi-stage absorption tower 12, and the ammonia in the exhaust gas contacts with the absorption liquid in the ammonia absorption tower 10 and the multi-stage absorption tower 12; the ammonia is dispersed in the absorption liquid in the form of microbubbles, which increases the gas-liquid contact area and improves the absorption efficiency; in particular, the multi-stage design of the multi-stage absorption tower 12 can further ensure the full absorption of ammonia.

[0067] Through the above-mentioned design, the recovery rate of the output gas ammonia of the present invention is above 99.5%, and at the same time, ammonia water with a concentration of 15-25% can be produced under normal temperature conditions; the entire system has high absorption efficiency, stable absorption, and small footprint. At the same time, the system is equipped with an automated control equipment system, which is visualized, intelligent, and has high work efficiency. During the operation of the system, key nodes such as the temperature, vacuum pressure, flow, pH value, liquid level, tail gas concentration, and ammonia water concentration of the dehydration and absorption tank are intelligently controlled.

[0068] In order to achieve a better ammonia enrichment effect, in a specific embodiment, as Figure 3 As shown, in the circulation system, more than two second ammonia recovery systems 5 can be set between the first ammonia recovery system 4 and the third ammonia recovery system 6, and the multiple second ammonia recovery systems 5 are connected in sequence; in this way, the treated waste gas of the first ammonia recovery system 4 can be processed in sequence through the multiple second ammonia recovery systems 5, and then transmitted to the third ammonia recovery system 6, so as to achieve better ammonia enrichment effect.

[0069] Based on the aforementioned ammonia absorption circulation system, the present invention also proposes an ammonia absorption circulation method, which is used to absorb and circulate ammonia in the exhaust gas of the industrial system 3, such as Figure 4 As shown, the method includes:

[0070] Step S1, condensing and falling film treating the waste gas and passing it into water for ammonia extraction treating to generate ammonia water and the waste gas after primary treatment;

[0071] The step S1 is that the waste gas enters the first ammonia recovery system 4 and is condensed and film-fallen by the condensation film falling device 7; the condensation temperature is 30°C~38°C, the pressure is 0.16MPa~0.18MPa, and condensed gaseous ammonia is generated; and the gaseous ammonia is passed into the dilute ammonia water tank to generate ammonia water.

[0072] Step S2, using fillers to enrich ammonia in the waste gas after primary treatment, and adding an absorption liquid above the fillers to wash the fillers, thereby generating ammonia water and waste gas after secondary treatment;

[0073] The step S2 is that the waste gas after the primary treatment enters the second ammonia recovery system 5, and the ammonia is enriched by the ammonia absorption tower 10; in a preferred embodiment, the filler can be a metal ring saddle, which has high wear resistance and can withstand large pressure and friction without being easily damaged. At the same time, its extremely high hardness and strength also ensure the reliability of long-term use. At the same time, the metal ring saddle has good corrosion resistance, can remain stable in harsh environments such as acid and alkali, and is not easily corroded.

[0074] Step S3, performing multi-stage treatment on the secondary treated waste gas to generate ammonia water and tertiary treated waste gas;

[0075] The step S3 is that the waste gas after secondary treatment enters the multi-stage absorption tower 12, and is started in the order of the primary absorption tower 121, the secondary absorption tower 122, the tertiary absorption tower 123, and the quaternary absorption tower 124 to achieve the enrichment of ammonia.

[0076] Step S4, performing waste gas post-treatment on the waste gas after the three treatments;

[0077] Step S5, end the process.

[0078] In a specific embodiment, step S3 includes:

[0079] Step S31, the primary absorption tower 121 condenses the secondary treated exhaust gas at a temperature of 30°C to 50°C and a pressure of 0.16MPa to 0.18MPa to generate ammonia water;

[0080] Step S32, the secondary absorption tower 122 condenses the gas from the primary absorption tower 121, the condensation temperature is 30°C to 40°C, the pressure is 0.17 MPa, and ammonia water is generated;

[0081] Step S33, the third-stage absorption tower 123 enriches the ammonia gas from the gas from the second-stage absorption tower 122 through a metal ring saddle packing;

[0082] Step S34, adding absorption liquid to the fourth-stage absorption tower 124, the fourth-stage absorption tower 124 enriches the gas from the third-stage absorption tower 123 through the venturi jet system; and the absorption liquid flows through the third-stage absorption tower 123 to generate ammonia water and tertiary treated waste gas.

[0083] In addition, in a preferred embodiment, after step S34, the waste gas after the tertiary treatment may be sprayed with an absorption liquid again, and the absorption liquid may be water, etc. Moreover, the higher the absorption tower, the greater the negative pressure, so as to achieve an excellent enrichment effect.

[0084] Specifically, when the concentration of the absorption liquid reaches 15% to 20% in the process of enriching ammonia, it is mature ammonia water, and the ammonia water can be loaded into the first transfer tank 8, the second transfer tank 11 and the third transfer tank 13; and then transferred to the ammonia water storage tank 1 to complete the whole process. As for how to confirm the concentration, as mentioned above, the present invention adopts an automatic control equipment system, which is a prior art and will not be described in detail here.

[0085] In a specific embodiment, step S4 includes: passing 5% to 10% dilute sulfuric acid, dilute hydrochloric acid or dilute phosphoric acid into the waste gas after the three treatments, so that a trace amount of ammonia reacts with the dilute acid to become usable ammonium sulfate (or ammonium chloride or ammonium phosphate). In this way, the ammonia tail gas is treated by the device of this design, and the ammonia content is ≤0.5mg / m3, which meets the environmental protection standards, and the purity of the recovered ammonium sulfate is ≥97%, and the harmless residual gas can be discharged from the system normally.

[0086] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. An ammonia absorption circulation system, characterized in that: The circulation system absorbs and circulates ammonia gas in the waste gas generated by the industrial system (3), and the circulation system comprises: An ammonia water storage tank (1), used for storing ammonia water; A first ammonia recovery system (4) is connected to the ammonia water storage tank (1) and the industrial system (3), respectively; the first ammonia recovery system (4) receives waste gas from the industrial system (3), condenses and forms a film on the waste gas, and passes the condensed and formed waste gas into water to generate ammonia water, and extracts the ammonia water therein and transmits it to the ammonia water storage tank (1); The second ammonia recovery system (5) is connected to the first ammonia recovery system (4), receives the treated waste gas from the first ammonia recovery system (4), enriches the ammonia in the waste gas to generate ammonia water, extracts the ammonia water therein and transmits it to the first ammonia recovery system (4), and then the first ammonia recovery system (4) transmits the ammonia water to the ammonia water storage tank (1); The third ammonia recovery system (6) is connected to the second ammonia recovery system (5), receives the treated waste gas from the second ammonia recovery system (5), enriches the ammonia in the waste gas to generate ammonia water, extracts the ammonia water therein and transmits it to the second ammonia recovery system (5), transmits it from the second ammonia recovery system (5) to the first ammonia recovery system (4), and then transmits the ammonia water from the first ammonia recovery system (4) to the ammonia water storage tank (1).

2. The ammonia absorption circulation system according to claim 1, characterized in that: The circulation system comprises: an exhaust gas post-processor (2), which is connected to the third ammonia recovery system (6), receives the treated exhaust gas from the third ammonia recovery system (6), and neutralizes the treated exhaust gas.

3. The ammonia absorption circulation system according to claim 2, characterized in that: The first ammonia recovery system (4) comprises: The condensing film falling device (7) is connected to the industrial system, receives the waste gas from the industrial system (3), and condenses the waste gas to generate condensed gaseous ammonia; a dilute ammonia water tank, the dilute ammonia water tank being connected to the condensing film falling device (7) and the second ammonia recovery system (5) respectively; the dilute ammonia water tank stores water, receives gaseous ammonia from the condensing film falling device (7), and generates ammonia water; the dilute ammonia water tank transmits the treated waste gas to the second ammonia recovery system (5); The first transfer tank (8) is connected to the dilute ammonia water tank and the ammonia water storage tank (1) respectively, receives ammonia water from the dilute ammonia water tank, and transmits it to the ammonia water storage tank (1).

4. The ammonia absorption circulation system according to claim 3, characterized in that: The second ammonia recovery system (5) comprises: an ammonia absorption tower (10), the ammonia absorption tower (10) being connected to the dilute ammonia water tank, receiving the treated waste gas from the dilute ammonia water tank, extracting ammonia from the waste gas to generate ammonia water, and transmitting the treated waste gas to a third ammonia recovery system (6); The second transfer tank (11) is connected to the ammonia absorption tower (10) and the first transfer tank (8) respectively, receives ammonia water from the ammonia absorption tower (10), transmits it to the first transfer tank (8), and then transmits it to the ammonia water storage tank (1) from the first transfer tank (8).

5. The ammonia absorption circulation system according to claim 4, characterized in that: The third ammonia recovery system (6) comprises: a multi-stage absorption tower (12), the multi-stage absorption tower (12) being connected to the ammonia absorption tower (10) and the waste gas post-processor (2) respectively, receiving the treated waste gas from the ammonia absorption tower (10), extracting ammonia from the waste gas, generating ammonia water, and transmitting the treated waste gas to the waste gas post-processor (2); The third transfer tank (13) is connected to the multi-stage absorption tower (12) and the second transfer tank (11) respectively, receives the ammonia water from the multi-stage absorption tower (12), transfers it to the second transfer tank (11), transfers it from the second transfer tank (11) to the first transfer tank (8), and then transfers it from the first transfer tank (8) to the ammonia water storage tank (1).

6. The ammonia absorption circulation system according to claim 5, characterized in that: The dilute ammonia water tank is connected to the first transfer tank (8) by a cooling pipeline (9); the ammonia absorption tower (10) is connected to the second transfer tank (11) by a cooling pipeline (9); and the multi-stage absorption tower (12) is connected to the third transfer tank (13) by a cooling pipeline (9).

7. The ammonia absorption circulation system according to claim 6, characterized in that: The multi-stage absorption tower (12) comprises: a primary absorption tower (121), the primary absorption tower (121) being connected to the ammonia absorption tower (10) and the third transfer tank (13) respectively, and being provided with a condenser, receiving the treated waste gas from the ammonia absorption tower (10), extracting ammonia from the waste gas, and generating ammonia water; A secondary absorption tower (122), the secondary absorption tower (122) is connected to the primary absorption tower (121), and is provided with a condenser. The secondary absorption tower (122) receives the treated waste gas from the primary absorption tower (121), extracts ammonia from the waste gas, and generates ammonia water; A tertiary absorption tower (123), wherein the tertiary absorption tower (123) is connected to the secondary absorption tower (122), the tertiary absorption tower (123) receives the treated exhaust gas from the secondary absorption tower (122), and a corresponding filler for absorbing ammonia is arranged inside the tertiary absorption tower (123); A fourth-stage absorption tower (124) is connected to the third-stage absorption tower (123) and the exhaust gas post-processor (2) respectively, and is provided with corresponding fillers for absorbing ammonia.

8. An ammonia absorption circulation method, characterized in that: The method is implemented by an ammonia absorption circulation system as claimed in claims 1 to 7, and the method comprises: Step S1, condensing the waste gas and passing it into water for ammonia extraction to generate ammonia water and the waste gas after primary treatment; the condensation temperature is 30°C to 38°C, and the pressure is 0.16MPa to 0.18MPa; Step S2, using fillers to enrich ammonia gas in the waste gas after primary treatment, and adding an absorption liquid above the fillers to wash the fillers to generate ammonia water and waste gas after secondary treatment, wherein the fillers are metal ring saddles; Step S3, performing multi-stage treatment on the secondary treated waste gas to generate ammonia water and tertiary treated waste gas; Step S4, performing waste gas post-treatment on the waste gas after the three treatments; Step S5, end the process.

9. The ammonia absorption circulation method according to claim 8, characterized in that: The step S3 comprises: Step S31, condensing the waste gas after secondary treatment, wherein the condensation temperature is 30°C to 50°C and the pressure is 0.16MPa to 0.18MPa to generate ammonia water; Step S32, condensing the gas at a temperature of 30°C to 40°C and a pressure of 0.17 MPa to generate ammonia water; Step S33, enriching the gas with ammonia through a metal ring saddle packing; Step S34, adding absorption liquid above the metal ring saddle filler, enriching the gas through the Venturi jet system to generate ammonia water and tertiary treated waste gas.

10. The ammonia absorption circulation method according to claim 8, characterized in that: The step S4 comprises: introducing 5% to 10% dilute sulfuric acid, dilute hydrochloric acid or dilute phosphoric acid into the waste gas after the three treatments.

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