Ammonia synthesis purge gas recovery unit

Abstract

The utility model discloses an ammonia synthesis purge gas recovery unit which comprises a water scrubber and a mechanical ammonia water clarifying tank, the water scrubber is connected with a gas inlet pipe and a spray pipe, the bottom of the water scrubber is connected with a water outlet pipe, and the water outlet pipe is provided with a pumping device. The water outlet pipe is respectively connected with a mechanical ammonia water clarifying tank and a dilute ammonia water buffer tank through a tee joint and a pipeline; the bottom of the dilute ammonia water buffer tank is connected with an evaporation tank through a pipeline and a pumping device, the bottom of the evaporation tank is connected with a mechanical ammonia water clarifying tank through a pipeline and a pumping device, the top of the evaporation tank is provided with a breather pipe and an air outlet pipe, the air outlet pipe is provided with a fan, and the air outlet pipe is connected with a super ammonia absorber; the energy utilization rate can be improved, and the production cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of ammonia recovery, in particular to an ammonia synthesis purge gas recovery unit. Background Art

[0002] In the production of synthetic ammonia, to ensure the effective gas composition of the synthesis cycle gas, inert gases must be continuously discharged. A synthesis purge gas outlet is located at the outlet of the ammonia synthesis cycle. Synthesis purge gas contains approximately 55% hydrogen and 5% ammonia. Directly discharging this purge gas to a flare would be a significant waste for the ammonia synthesis plant and increase production costs.

[0003] To recover the active ingredients in synthesis purge gas, ammonia recovery and hydrogen recovery equipment are typically installed downstream of ammonia synthesis. During synthesis purge gas pretreatment, desalted water and purge gas come into countercurrent contact in a water scrubber, utilizing ammonia's high absorbability in water to scrub away ammonia from the purge gas. This dilute ammonia solution, with a concentration of 3% to 5%, is then sent to the mechanized ammonia clarifier in the chemical production plant. However, this ammonia solution is formed by dissolving clean desalted water and ammonia gas, making its effective utilization crucial. Utility Model Content

[0004] In view of the defects in the prior art, the utility model provides an ammonia synthesis purge gas recovery unit.

[0005] The utility model is realized through the following technical solutions:

[0006] An ammonia synthesis purge gas recovery unit comprises a water scrubber and a mechanized ammonia solution clarifier, wherein the bottom of the water scrubber is connected to an air inlet pipe, the top of the water scrubber is connected to a spray pipe, and the spray pipe is connected to a water storage tank through a pumping device; the bottom of the water scrubber is connected to a water outlet pipe, the water outlet pipe is provided with a pumping device, the water outlet pipe is respectively connected to a mechanized ammonia solution clarifier and a dilute ammonia solution buffer tank through a tee and a pipeline, and an electromagnetic valve is provided on the pipeline between the mechanized ammonia solution clarifier and the tee, and on the pipeline between the dilute ammonia solution buffer tank and the tee; the bottom of the dilute ammonia solution buffer tank is connected to an evaporation tank through a pipeline and a pumping device, and the bottom of the evaporation tank is connected to the mechanized ammonia solution clarifier through a pipeline and a pumping device; the top of the evaporation tank is provided with a vent pipe extending into the evaporation tank, and the top of the evaporation tank is also provided with an air outlet pipe, the air outlet pipe is provided with a fan, and the air outlet pipe is connected to a super ammonia absorber.

[0007] Preferably, liquid level sensors are provided on the side walls of the dilute ammonia solution buffer tank and the side walls of the evaporation tank.

[0008] Preferably, a heating base is provided at the bottom of the evaporation tank.

[0009] Preferably, an ammonia concentration sensor is provided at the bottom of the evaporation tank.

[0010] Preferably, an ammonia concentration sensor is provided on the air outlet pipe.

[0011] Preferably, the pumping device is a water pump.

[0012] The beneficial effects of the present invention are as follows: the present invention sends the low-concentration ammonia water washed by hydrogen recovery to the dilute ammonia water buffer tank through the ammonia water pipeline, and then recovers ammonia through the evaporation tank and the super ammonia absorber to form dilute ammonia water. The present invention can improve energy utilization and maximize benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0014] Figure 1 This is the overall structure diagram of the utility model.

[0015] Figure 2 This is a structural view of the dilute ammonia water buffer tank of the utility model.

[0016] Figure 3 This is a structural view of the evaporation tank of the present utility model.

[0017] Figure 4 for Figure 1 Enlarged view of point A.

[0018] In the attached figure, 1. air inlet pipe; 2. spray pipe; 3. water storage tank; 4. water washing tower; 5. water outlet pipe; 6. solenoid valve; 7. mechanized ammonia clarification tank; 8. dilute ammonia buffer tank; 9. liquid level sensor; 10. evaporation tank; 11. ammonia concentration sensor; 12. ventilation pipe; 13. heating base; 14. air outlet pipe; 15. fan; 16. ammonia concentration sensor; 17. super ammonia absorber; 18. water pump. DETAILED DESCRIPTION

[0019] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0020] It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0021] For ease of description, spatially relative terms such as "upper," "lower," "left," and "right" may be used herein to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that the spatial terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures is inverted, an element described as being "below" another element or feature would be positioned "above" the other element or feature. Thus, the exemplary term "below" can encompass both above and below orientations.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of this invention are intended only to describe specific embodiments and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] The following is a detailed description of the present invention in conjunction with the accompanying drawings: The present invention is an ammonia synthesis purge gas recovery unit, comprising a water scrubber 4 and a mechanized ammonia solution clarifier 7, wherein the bottom of the water scrubber 4 is connected to an air inlet pipe 1, the top of the water scrubber 4 is connected to a spray pipe 2, the spray pipe 2 is connected to a water storage tank 3 through a pumping device, and the water storage tank 3 contains desalted water; the bottom of the water scrubber 4 is connected to a water outlet pipe 5, the water outlet pipe 5 is provided with a pumping device, and the water outlet pipe 5 is connected to a mechanized ammonia solution clarifier 7 and a dilute ammonia solution buffer tank 8 through a tee and a pipeline, A solenoid valve 6 is provided on the pipeline between the mechanized ammonia solution clarification tank 7 and the tee, and on the pipeline between the dilute ammonia solution buffer tank 8 and the tee; the bottom of the dilute ammonia solution buffer tank 8 is connected to the evaporation tank 10 through a pipeline and a pumping device, and the bottom of the evaporation tank 10 is connected to the mechanized ammonia solution clarification tank 7 through a pipeline and a pumping device; the top of the evaporation tank 10 is provided with a ventilation pipe 12 extending into the evaporation tank 10, and the top of the evaporation tank 10 is also provided with an outlet pipe 14, on which a fan 15 is provided, and the outlet pipe 14 is connected to a super ammonia absorber 17.

[0024] Liquid level sensors 9 are provided on the side walls of the dilute ammonia solution buffer tank 8 and the side walls of the evaporation tank 10 .

[0025] A heating base 13 is provided at the bottom of the evaporation tank 10 .

[0026] An ammonia concentration sensor 11 is provided at the bottom of the evaporation tank 10 .

[0027] An ammonia concentration sensor is provided on the gas outlet pipe 14 .

[0028] The pumping device is a water pump 18 .

[0029] The working principle of the utility model is as follows: the purge gas enters the water washing tower 4 through the air inlet pipe 1, and the desalted water in the water washing tower 4 contacts the purge gas in reverse, and the high absorbency of ammonia in water is utilized to wash away the ammonia in the purge gas; the dilute ammonia water produced after washing needs to enter the dilute ammonia water buffer tank 8 first, and when the liquid level sensor 9 in the dilute ammonia water buffer tank 8 does not detect the liquid level information, the controller controls the solenoid valve 6 in the direction of the dilute ammonia water buffer tank 8 to open, and controls the solenoid valve 6 in the direction of the mechanized ammonia water clarification tank 7 to close, so that the washed dilute ammonia water enters the dilute ammonia water buffer tank 8, and when the liquid level sensor 9 in the dilute ammonia water buffer tank 8 detects the liquid level information, the controller controls the solenoid valve 6 in the direction of the dilute ammonia water buffer tank 8 to close, and controls the solenoid valve 6 in the direction of the mechanized ammonia water clarification tank 7 to open, so that the dilute ammonia water enters the mechanized ammonia water clarification tank 7.

[0030] The dilute ammonia solution in the dilute ammonia solution buffer tank 8 is pumped into the evaporation tank 10 by the water pump 18. When the liquid level sensor 9 in the evaporation tank 10 detects the liquid level information, the water pump 18 in the pipeline between the dilute ammonia solution buffer tank 8 and the evaporation tank 10 is controlled to stop working. The ammonia gas in the dilute ammonia solution is volatilized by heating the heating base, and then the ammonia gas is introduced into the super ammonia absorber 17 for ammonia recovery by the fan 15.

[0031] The ammonia concentration sensor 11 in the evaporation tank 10 can detect the concentration of the ammonia. When it is detected that the ammonia concentration in the evaporation tank 10 is lower than the set value, the water pump 18 between the evaporation tank 10 and the mechanized ammonia clarification tank can pump the liquid in the evaporation tank 10 into the mechanized ammonia clarification tank for recovery of other components.

[0032] The ammonia concentration sensor provided on the air outlet pipe can detect the concentration of ammonia, and the speed of the fan 15 can be adjusted according to the concentration of ammonia. For example, when the ammonia concentration is higher or lower than the preset value, the controller adjusts the fan 15 to a different speed. The speed of the fan 15 can also be dynamically adjusted according to the ammonia concentration through program setting.

[0033] The unit of the present invention is controlled by a PLC controller, which is respectively connected to each water pump 18, two solenoid valves 6, two liquid level sensors 9, a fan 15, an ammonia concentration sensor and an ammonia concentration sensor 11, and is programmed according to the PLC program to realize control of each component.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. An ammonia synthesis purge gas recovery unit, comprising a water scrubber (4) and a mechanized ammonia clarifier (7), characterized in that: The bottom of the water washing tower (4) is connected to an air inlet pipe (1), and the top of the water washing tower (4) is connected to a spray pipe (2), which is connected to a water storage tank (3) via a pumping device; the bottom of the water washing tower (4) is connected to a water outlet pipe (5), which is provided with a pumping device, and the water outlet pipe (5) is respectively connected to a mechanized ammonia water clarification tank (7) and a dilute ammonia water buffer tank (8) via a tee and a pipeline, and the pipeline between the mechanized ammonia water clarification tank (7) and the tee and between the dilute ammonia water buffer tank (8) and the tee. A solenoid valve (6) is provided on the pipeline between the dilute ammonia buffer tank (8); the bottom of the dilute ammonia buffer tank (8) is connected to the evaporation tank (10) through a pipeline and a pumping device, and the bottom of the evaporation tank (10) is connected to the mechanized ammonia clarification tank (7) through a pipeline and a pumping device; the top of the evaporation tank (10) is provided with a ventilation pipe (12) extending into the evaporation tank (10), and the top of the evaporation tank (10) is also provided with an outlet pipe (14), a fan (15) is provided on the outlet pipe (14), and the outlet pipe (14) is connected to the super ammonia absorber (17).

2. The ammonia synthesis purge gas recovery unit according to claim 1, characterized in that: Liquid level sensors (9) are provided on the side walls of the dilute ammonia buffer tank (8) and the side walls of the evaporation tank (10).

3. The ammonia synthesis purge gas recovery unit according to claim 1, characterized in that: A heating base (13) is provided at the bottom of the evaporation tank (10).

4. The ammonia synthesis purge gas recovery unit according to claim 1, characterized in that: An ammonia concentration sensor (11) is provided at the bottom of the evaporation tank (10).

5. The ammonia synthesis purge gas recovery unit according to claim 1, characterized in that: An ammonia concentration sensor is provided on the gas outlet pipe (14).

6. The ammonia synthesis purge gas recovery unit according to claim 1, characterized in that: The pumping device is a water pump (18).

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