A low-temperature cooling and purification device for synthesis gas in synthetic ammonia

Abstract

The present invention discloses a low-temperature cooling and purification device for synthesis gas used in ammonia synthesis, and relates to the technical field of ammonia synthesis. The present invention comprises a cooling cylinder, a dryer, and a purification cylinder. The outlet of the cooling cylinder is connected to the inlet of the dryer through a pipe, and the outlet of the dryer is connected to the inlet of the purification cylinder through a pipe. A main fan is provided on the pipe between the dryer and the purification cylinder. Three cooling assemblies are provided vertically and evenly spaced inside the cooling cylinder. The cooling assemblies include a bottom baffle, an intermediate air inlet pipe, a cylinder, a cross-shaped support frame, and a nozzle. The intermediate air inlet pipe is fixed to the center of the bottom baffle. By providing a cooling cylinder, a dryer, and a purification cylinder, the present invention can spray-cool and purify the synthesis gas, absorb saturated water in the synthesis gas, and remove catalyst dust in the synthesis gas to obtain gas that meets the requirements of the ammonia synthesis system. This solves the problem of low cooling and purification efficiency and unsatisfactory effects of existing synthesis gas cooling and purification devices.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic ammonia, and in particular relates to a low-temperature cooling and purification device for synthetic gas used in synthetic ammonia. Background Art

[0002] Synthesis gas can only be converted into ammonia under high pressure and high temperature with the help of a catalyst. The gas entering the ammonia synthesis system needs to be pressurized by a compressor before entering the ammonia synthesis tower. However, the existing synthesis gas has the following problems:

[0003] 1. The outlet gas temperature of the syngas water cooler is 40°C, which results in a high inlet temperature of the syngas entering the compressor. This reduces the actual intake volume of the compressor and reduces the efficiency of the compressor. The high temperature also causes the compressor lubrication to fail, affecting moving parts such as the compressor piston rings.

[0004] 2. Before the synthesis gas enters the compressor, the trace carbon monoxide and carbon dioxide in the synthesis gas must be removed by methanation catalysis. The synthesis gas leaving the methanation furnace inevitably carries catalyst dust. The dust is brought into the compressor system along with the synthesis gas, and the dust will be attached to the compressor impeller and rotor, causing the compressor power consumption and consumption to increase, and prone to failure.

[0005] A search revealed publication number CN107586569A, dated January 16, 2018, which discloses a high-temperature crude syngas cooling and purification device. The device comprises an inlet spray cooling device, the inlet of which is connected to the outlet of the gasification chamber. Multiple nozzles are positioned on the sidewalls of the device, spraying water mist into the high-temperature crude syngas to rapidly cool it. A gas-carrying water-cooled wall conveys syngas and fly ash downward along the inner side of the water-cooled wall for a distance, providing space for the water mist and crude syngas to mix and cool. A descending gas multi-layer atomization cooling and wetting device, located on the gas-carrying water-cooled wall, sprays water mist into the inner space of the water-cooled wall through multiple nozzles. An ascending gas multi-layer atomization cooling and wetting device, using multiple nozzles to spray water mist into the middle and lower portion of the space formed by the descending water-cooled wall and the shell, is also included. The device utilizes water mist cooling, which improves cooling efficiency, reduces cooling water usage, reduces system circulating water volume, and facilitates ashwater treatment.

[0006] This patent has the following deficiencies:

[0007] 1. The syngas flow rate of the cooling and purification unit was too high, resulting in insufficient contact between the syngas and the water mist;

[0008] 2. The cooling and purification device has difficulty removing catalyst dust entrained in the synthesis gas. When the dust is brought into the compressor system along with the synthesis gas, it is easy to cause compressor failure.

[0009] Therefore, the existing synthesis gas cooling and purification device cannot meet the needs of actual use, so there is an urgent need for improved technology in the market to solve the above problems. Summary of the Invention

[0010] The object of the present invention is to provide a low-temperature cooling and purification device for synthesis gas used in ammonia synthesis. By arranging a cooling cylinder, a dryer and a purification cylinder, the synthesis gas can be spray-cooled and purified, saturated water in the synthesis gas can be absorbed, and catalyst dust in the synthesis gas can be removed to obtain gas that meets the requirements of the ammonia synthesis system. This solves the problem of low cooling and purification efficiency and unsatisfactory effect of existing synthesis gas cooling and purification devices.

[0011] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0012] The present invention is a low-temperature cooling and purification device for synthesis gas in synthetic ammonia, comprising a cooling cylinder, a dryer and a purification cylinder. The outlet of the cooling cylinder is connected to the inlet of the dryer through a pipeline, and the outlet of the dryer is connected to the inlet of the purification cylinder through a pipeline. A main fan is provided on the pipeline between the dryer and the purification cylinder.

[0013] Three cooling components are arranged vertically and evenly spaced inside the cooling cylinder. The cooling components include a bottom baffle, an intermediate air inlet pipe, a cylinder, a cross-shaped support frame and a nozzle. The intermediate air inlet pipe is fixed at the center of the bottom baffle, and the top end of the intermediate air inlet pipe is inserted into the cylinder. The cylinder is fixed to the inner wall of the cooling cylinder through a cross-shaped support frame. A plurality of nozzles evenly distributed along the circumference are arranged on the inner wall of the cylinder.

[0014] Three molecular sieve layers with equal vertical spacing are arranged inside the purification cylinder, and an activated carbon layer is arranged above the molecular sieve layers; a regeneration component and a driving mechanism are also arranged inside the purification cylinder. The regeneration component is used to heat and regenerate the three molecular sieve layers, and the driving mechanism drives the regeneration component to rotate locally through mechanical transmission to stir the molecular sieve layers.

[0015] Furthermore, the nozzle is tilted downward, and its height is lower than the top height of the middle air inlet pipe.

[0016] Furthermore, a cooling cylinder air inlet pipe is provided at the bottom center of the cooling cylinder, and a cooling cylinder air outlet pipe is provided at the top center of the cooling cylinder; three drainage pipes are provided on the cylindrical surface of the cooling cylinder at equal vertical intervals, and the three drainage pipes correspond one to one to the three cooling components.

[0017] Furthermore, a conical cylinder is fixed at the bottom of the purification cylinder, and three layers of air distribution plates are arranged inside the conical cylinder; a purification cylinder air inlet pipe is arranged at the bottom center of the conical cylinder, and a purification cylinder air outlet pipe is arranged at the top center of the purification cylinder.

[0018] Furthermore, the molecular sieve layer includes a porous plate, a central tube and a molecular sieve body; the central tube is fixed at the center of the porous plate, and the molecular sieve body is placed on the top of the porous plate.

[0019] Furthermore, the regeneration component includes a vertical pipe, a stirring frame, a rotary joint and a T-shaped pipe; the vertical pipe passes through the central tube and extends to the inner lower end of the purification tube, and three stirring frames distributed vertically and evenly spaced are provided on the vertical pipe. The stirring frame is made of a hollow pipe, which is connected to the vertical pipe, and air outlet holes are provided on the support legs of the stirring frame; the top of the vertical pipe is connected to the T-shaped pipe through a rotary joint.

[0020] Furthermore, the regeneration component also includes a hot air blower, a first purification box, a cold air blower, a second purification box and a solenoid valve; one end of the T-tube is fixedly connected to the outlet of the hot air blower, and the inlet of the hot air blower is fixedly connected to the outlet of the first purification box through a pipe; the other end of the T-tube is fixedly connected to the outlet of the cold air blower, and the inlet of the cold air blower is fixedly connected to the outlet of the second purification box through a pipe; solenoid valves are provided at both ends of the T-tube; the hot air blower and the first purification box are fixed on one side of the outside of the purification cylinder, and the cold air blower and the second purification box are fixed on the other side of the outside of the purification cylinder.

[0021] Furthermore, the driving mechanism includes a support plate, a gear ring, a gear and a motor; the upper end of the vertical pipe is fixed on the support plate, the support plate is fixed across the top of the gear ring, the gear ring is supported by a support frame, the gear ring is meshed with the gear, the gear is fixed on the output shaft of the motor, and the motor is fixed on the outer surface of the purification cylinder.

[0022] The present invention has the following beneficial effects:

[0023] The present invention can spray-cool and purify the synthesis gas by arranging a cooling cylinder, a dryer and a purification cylinder, absorb saturated water in the synthesis gas, and remove catalyst dust in the synthesis gas to obtain gas that meets the requirements of the ammonia synthesis system.

[0024] The present invention provides a better cooling effect of the cooling assembly by arranging a bottom baffle, an intermediate air inlet pipe, a cylinder and a nozzle, can buffer and reduce the speed of the synthesis gas entering the cooling cylinder, and allows the water mist to fully contact the synthesis gas, thereby achieving the purpose of rapid cooling.

[0025] The present invention provides a regeneration component so that the molecular sieve layer has a regeneration function. The molecular sieve layer can be heated, regenerated and cooled by the regeneration component, thereby improving the service life of the molecular sieve layer. In addition, by providing a driving mechanism, a stirring frame and an air outlet, the stirring frame can stir the molecular sieve body, so that the hot air can fully contact all parts of the molecular sieve body, resulting in higher regeneration efficiency and better effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 Schematic diagram of the overall structure appearance;

[0028] Figure 2 Schematic diagram of the internal structure of the cooling cylinder;

[0029] Figure 3 Schematic diagram of the cooling component structure;

[0030] Figure 4 Schematic diagram of the internal structure of the purification cylinder;

[0031] Figure 5 Schematic diagram of the molecular sieve layer structure;

[0032] Figure 6 Schematic diagram of the regeneration component structure;

[0033] Figure 7 Schematic diagram of the driving mechanism structure.

[0034] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0035] 1. Cooling cylinder; 2. Dryer; 3. Purification cylinder; 4. Main fan; 5. Cooling assembly; 6. Molecular sieve layer; 7. Activated carbon layer; 8. Regeneration assembly; 9. Driving mechanism; 11. Cooling cylinder air inlet pipe; 12. Cooling cylinder air outlet pipe; 13. Drain pipe; 31. Conical cylinder; 32. Purification cylinder air inlet pipe; 33. Air distribution plate; 34. Purification cylinder air outlet pipe; 51. Bottom baffle; 52. Middle air inlet pipe; 53. Cylinder body; 54, cross-shaped support frame; 55, nozzle; 61, porous plate; 62, central tube; 63, molecular sieve body; 81, vertical pipe; 82, stirring frame; 83, air outlet; 84, rotary joint; 85, T-shaped pipe; 86, hot air blower; 87, first purification box; 88, cold air blower; 89, second purification box; 810, solenoid valve; 91, support plate; 92, gear ring; 93, gear; 94, motor. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0037] See also Figure 1As shown, the present invention is a low-temperature cooling and purification device for synthesis gas in synthetic ammonia, comprising a cooling cylinder 1, a dryer 2 and a purification cylinder 3. The outlet of the cooling cylinder 1 is connected to the inlet of the dryer 2 through a pipeline, and the outlet of the dryer 2 is connected to the inlet of the purification cylinder 3 through a pipeline. A main fan 4 is provided on the pipeline between the dryer 2 and the purification cylinder 3.

[0038] Among them Figures 2-3 As shown, three cooling components 5 are provided inside the cooling cylinder 1 at equal vertical intervals, a cooling cylinder air inlet pipe 11 is provided at the bottom center of the cooling cylinder 1, and a cooling cylinder air outlet pipe 12 is provided at the top center of the cooling cylinder 1; three drainage pipes 13 are provided on the cylindrical surface of the cooling cylinder 1 at equal vertical intervals, and the three drainage pipes 13 correspond one to one to the three cooling components 5; the cooling component 5 includes a bottom baffle 51, an intermediate air inlet pipe 52, a cylinder body 53, a cross-shaped support frame 54 and a nozzle 55; the intermediate air inlet pipe 52 is fixed at the center of the bottom baffle 51, the top end of the intermediate air inlet pipe 52 is inserted into the cylinder body 53, and the cylinder body 53 is fixed to the inner wall of the cooling cylinder 1 through the cross-shaped support frame 54, and a plurality of nozzles 55 evenly distributed along the circumference are provided on the inner wall of the cylinder body 53, and the nozzles 55 are tilted downward, and their height is lower than the height of the top end of the intermediate air inlet pipe 52.

[0039] Among them Figure 4 As shown, a conical cylinder 31 is fixed at the bottom of the purification cylinder 3, and three layers of air equalizing plates 33 are arranged inside the conical cylinder 31; a purification cylinder air inlet pipe 32 is arranged at the bottom center of the conical cylinder 31, and a purification cylinder air outlet pipe 34 is arranged at the top center of the purification cylinder 3; three vertically equidistantly distributed molecular sieve layers 6 are arranged inside the purification cylinder 3, and an activated carbon layer 7 is arranged above the molecular sieve layer 6; a regeneration component 8 and a driving mechanism 9 are also provided inside the purification cylinder 3, and the regeneration component 8 is used to heat and regenerate the three molecular sieve layers 6, and the driving mechanism 9 drives the regeneration component 8 to rotate locally through mechanical transmission to stir the molecular sieve layer 6.

[0040] Among them Figure 5 As shown, the molecular sieve layer 6 includes a porous plate 61 , a central tube 62 and a molecular sieve body 63 ; the central tube 62 is fixed at the center of the porous plate 61 , and the molecular sieve body 63 is placed on the top of the porous plate 61 .

[0041] Among them Figure 6As shown, the regeneration assembly 8 includes a vertical pipe 81, a stirring frame 82, a rotary joint 84 and a T-shaped pipe 85; the vertical pipe 81 passes through the central tube 62 and extends to the lower end of the inner part of the purification tube 3. Three stirring frames 82 are vertically and evenly spaced on the vertical pipe 81. The stirring frames 82 are made of hollow pipes and are connected to the vertical pipe 81. The legs of the stirring frames 82 are provided with air outlets 83; the top of the vertical pipe 81 is connected to the T-shaped pipe 85 through a rotary joint 84; the regeneration assembly 8 also includes a hot air blower 86, a first purification box 87, a cold air blower 88, and a second purification box 89. and solenoid valve 810; one end of the T-tube 85 is fixedly connected to the outlet of the hot air blower 86, and the inlet of the hot air blower 86 is fixedly connected to the outlet of the first purification box 87 through a pipe; the other end of the T-tube 85 is fixedly connected to the outlet of the cold air blower 88, and the inlet of the cold air blower 88 is fixedly connected to the outlet of the second purification box 89 through a pipe; solenoid valves 810 are provided at both ends of the T-tube 85; the hot air blower 86 and the first purification box 87 are fixed on one side of the outside of the purification cylinder 3, and the cold air blower 88 and the second purification box 89 are fixed on the other side of the outside of the purification cylinder 3.

[0042] When the regeneration component 8 is used, the hot air blower 86 is started, and the hot air blower 86 draws the external ambient air into the first purification box 87. After being purified by the first purification box 87 and heated by the hot air blower 86, the hot air enters the vertical pipe 81 through the T-tube 85 and the rotary joint 84, and finally is ejected from the air outlet 83 on the stirring frame 82 to heat and regenerate the molecular sieve body 63 and take away the desorbed adsorbent. During the regeneration process, the stirring frame 82 is driven by the driving mechanism 9 to rotate and stir the molecular sieve body 63 so that the hot air can fully contact all parts of the molecular sieve body 63; after the heating is completed, the cold air blower 88 is started, and the cold air blower 88 draws the external ambient air into the second purification box 89. After being purified by the second purification box 89, the cold air enters the vertical pipe 81 through the T-tube 85 and the rotary joint 84, and finally is ejected from the air outlet 83 on the stirring frame 82 to cool the molecular sieve body 63 so that the molecular sieve body 63 can be put into production as soon as possible.

[0043] Among them Figure 7 As shown, the driving mechanism 9 includes a support plate 91, a ring gear 92, a gear 93 and a motor 94; the upper end of the vertical pipe 81 is fixed on the support plate 91, the support plate 91 is fixed across the top of the ring gear 92, the ring gear 92 is supported by a support frame, the ring gear 92 is meshed with the gear 93, the gear 93 is fixedly mounted on the output shaft of the motor 94, and the motor 94 is fixed on the outer surface of the purification cylinder 3.

[0044] When the driving mechanism 9 is used, the motor 94 drives the gear 93 to rotate, the gear 93 drives the ring gear 92 to rotate, the ring gear 92 drives the support plate 91 to rotate, the support plate 91 drives the vertical pipe 81 to rotate, and the vertical pipe 81 drives the stirring frame 82 to rotate, so that the molecular sieve body 63 can be stirred by the stirring frame 82.

[0045] The operation of this embodiment is as follows:

[0046] The synthesis gas enters the cooling cylinder 1 through the cooling cylinder air inlet pipe 11, is spray-cooled by the three-layer cooling assembly 5, and is discharged from the cooling cylinder air outlet pipe 12 and enters the dryer 2 for drying;

[0047] After drying, the synthesis gas enters the purification cylinder 3 through the purification cylinder air inlet pipe 32, is evenly diffused to various positions of the purification cylinder 3 by the three-layer air distribution plate 33, and is then purified by the three-layer molecular sieve layer 6 and the activated carbon layer 7 in sequence before being discharged from the device through the purification cylinder air outlet pipe 34.

[0048] The above are only preferred embodiments of the present invention and do not limit the present invention. Any modification to the technical solutions described in the aforementioned embodiments, any equivalent replacement of some of the technical features therein, and any modification, equivalent replacement, and improvement made are within the scope of protection of the present invention.

Claims

1. A low-temperature cooling and purification device for synthesis gas in ammonia synthesis, comprising a cooling cylinder (1), a dryer (2) and a purification cylinder (3), characterized in that: The outlet of the cooling cylinder (1) is connected to the inlet of the dryer (2) through a pipeline, and the outlet of the dryer (2) is connected to the inlet of the purification cylinder (3) through a pipeline. A main fan (4) is provided on the pipeline between the dryer (2) and the purification cylinder (3); Three cooling assemblies (5) are arranged vertically and evenly spaced inside the cooling cylinder (1), and the cooling assembly (5) includes a bottom baffle (51), an intermediate air inlet pipe (52), a cylinder (53), a cross-shaped support frame (54), and a nozzle (55); The middle air inlet pipe (52) is fixed at the center of the bottom baffle (51), the top end of the middle air inlet pipe (52) is inserted into the cylinder (53), the cylinder (53) is fixed to the inner wall of the cooling cylinder (1) through the cross-shaped support frame (54), and a plurality of nozzles (55) uniformly distributed along the circumference are provided on the inner wall of the cylinder (53); Three molecular sieve layers (6) are vertically and evenly spaced apart, and an activated carbon layer (7) is disposed above the molecular sieve layer (6). A regeneration component (8) and a driving mechanism (9) are further provided inside the purification cylinder (3). The regeneration component (8) is used to perform a heating and regeneration process on the three molecular sieve layers (6). The driving mechanism (9) drives the regeneration component (8) to rotate partially through mechanical transmission to stir the molecular sieve layers (6).

2. The low-temperature cooling and purification device for synthesis gas in ammonia synthesis according to claim 1, characterized in that: The nozzle (55) is arranged to be tilted downward, and its height is lower than the top height of the middle air inlet pipe (52).

3. The low-temperature cooling and purification device for synthesis gas in ammonia synthesis according to claim 1, characterized in that: A cooling cylinder air inlet pipe (11) is provided at the bottom center of the cooling cylinder (1), and a cooling cylinder air outlet pipe (12) is provided at the top center of the cooling cylinder (1); Three drainage pipes (13) are arranged on the cylindrical surface of the cooling cylinder (1) at equal intervals in a vertical direction, and the three drainage pipes (13) correspond one to one with the three cooling components (5).

4. The low-temperature cooling and purification device for synthesis gas used in ammonia synthesis according to claim 1, characterized in that: A conical cylinder (31) is fixed to the bottom of the purification cylinder (3), and three layers of air distribution plates (33) are arranged inside the conical cylinder (31); A purification cylinder air inlet pipe (32) is provided at the bottom center of the conical cylinder (31), and a purification cylinder air outlet pipe (34) is provided at the top center of the purification cylinder (3).

5. The low-temperature cooling and purification device for synthesis gas used in ammonia synthesis according to claim 1, characterized in that: The molecular sieve layer (6) includes a porous plate (61), a central tube (62) and a molecular sieve body (63); The center tube (62) is fixed at the center of the porous plate (61), and the molecular sieve body (63) is placed on the top of the porous plate (61).

6. The low-temperature cooling and purification device for synthesis gas used in ammonia synthesis according to claim 5, characterized in that: The regeneration assembly (8) includes a vertical pipe (81), a stirring frame (82), a rotary joint (84) and a T-shaped pipe (85); The vertical pipe (81) passes through the central tube (62) and extends to the lower end of the purification tube (3). Three stirring racks (82) are provided on the vertical pipe (81) and are distributed vertically and evenly. The stirring racks (82) are made of hollow pipes and are connected to the vertical pipe (81). The legs of the stirring racks (82) are provided with air outlet holes (83). The top end of the vertical pipe (81) is connected to the T-shaped pipe (85) via the rotary joint (84).

7. The low-temperature cooling and purification device for synthesis gas used in ammonia synthesis according to claim 6, characterized in that: The regeneration assembly (8) further includes a hot air blower (86), a first purification box (87), a cold air blower (88), a second purification box (89) and a solenoid valve (810); One end of the T-shaped tube (85) is fixedly connected to the outlet of the hot air blower (86), and the inlet of the hot air blower (86) is fixedly connected to the outlet of the first purification box (87) through a pipeline; The other end of the T-shaped tube (85) is fixedly connected to the outlet of the air cooler (88), and the inlet of the air cooler (88) is fixedly connected to the outlet of the second purification box (89) through a pipeline; Both ends of the T-shaped tube (85) are provided with solenoid valves (810); The hot air blower (86) and the first purification box (87) are both fixed to one side of the outside of the purification cylinder (3), and the cold air blower (88) and the second purification box (89) are both fixed to the other side of the outside of the purification cylinder (3).

8. The low-temperature cooling and purification device for synthesis gas used in ammonia synthesis according to claim 6, characterized in that: The driving mechanism (9) comprises a support plate (91), a gear ring (92), a gear (93) and a motor (94); The upper end of the vertical pipe (81) is fixed on the support plate (91), and the support plate (91) is fixed across the top of the ring gear (92). The ring gear (92) is supported by a support frame. The ring gear (92) is meshed with the gear (93). The gear (93) is fixedly sleeved on the output shaft of the motor (94), and the motor (94) is fixed on the outer surface of the purification cylinder (3).

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