Efficient ammonia still

Abstract

The utility model discloses a high-efficiency ammonia still, which belongs to the technical field of ammonia separation and comprises an upper seal head, a barrel, a lower seal head and a skirt, the barrel is sequentially provided with a feed distributor a, a tube nest heater, an arc-shaped partition plate, a feed distributor b and filler from top to bottom, the feed distributor a is connected with a feed port, and the lower seal head is connected with the skirt. A top end fixing plate and a bottom end fixing plate are arranged on the upper portion and the lower portion of the tube nest heater, the arc-shaped partition plate is communicated with the vapor phase outlet, the feeding distributor a and the feeding distributor b are identical in structure, the feeding distributor a comprises the top end fixing plate, the bottom end fixing plate, blades and a connecting plate, and the technical problem that existing equipment is high in production cost is solved. The method is mainly applied to ethanolamine production.

Description

Technical Field

[0001] The utility model belongs to the technical field of ammonia separation, and in particular relates to a high-efficiency ammonia distillation tower. Background Art

[0002] Ethanolamine is one of the main derivatives of ethylene oxide. It is widely used because of its molecular structure containing two active functional groups, hydroxyl and amino. The raw materials for the production of ethanolamine are ethylene oxide and liquid ammonia. To ensure the intrinsic safety of the reaction process, the raw material ratio of the reaction process must be an excess of liquid ammonia. In order to separate the unreacted ammonia, a process for removing excess ammonia must be set up after the reaction process, that is, the ammonia distillation process.

[0003] The ammonia evaporation process often uses an ammonia evaporation tower as the main ammonia separation equipment.

[0004] Patent CN220317460U discloses an energy-saving device for removing ammonia and recovering ammonia water, which adopts heat pump distillation and optimizes the structure of ammonia evaporation tower to greatly reduce the energy consumption of the production process.

[0005] Patent CN220695879U discloses an improved high-efficiency large-scale sieve plate ammonia distillation tower, which reduces the equipment manufacturing and maintenance costs by lowering the feed position, increasing the reaction time and height, and improving the tower's ammonia distillation efficiency. At present, there are two structural drawbacks in the ammonia distillation tower that need to be solved: First, the floating valve plate separation efficiency of the traditional ammonia distillation tower is low, the number of theoretical plates is large, and the tower body is relatively high. In addition, due to the strong corrosiveness of the medium, the material used to make the tower body also needs to have strong corrosion resistance, which leads to high tower body manufacturing costs. Second, ammonia is easily soluble in water, which makes separation difficult and consumes a lot of steam. The energy consumption of the ammonia distillation tower accounts for a large proportion in the ethanolamine production process. In order to solve the above drawbacks, we propose an efficient ammonia distillation tower. Summary of the invention

[0006] The purpose of the utility model is to provide a high-efficiency ammonia distillation tower with optimized structure, so as to solve the current situation of low separation efficiency, high equipment manufacturing cost and large steam consumption in the traditional ammonia distillation tower. The technical scheme adopted is as follows:

[0007] A high-efficiency ammonia distillation tower comprises an upper head, a cylinder, a lower head and a skirt. The upper and lower parts of the cylinder are sealed by the upper head and the lower head respectively. The cylinder is installed on the skirt. The upper part of the upper head is provided with a tower top vapor phase outlet. The cylinder is provided with a feed distributor a, a tube heater, an arc partition, a feed distributor b and fillers from top to bottom. The feed distributor a is connected to the feed port. The upper and lower parts of the tube heater are provided with a top fixing plate and a bottom fixing plate. The tube heater is provided with a steam inlet and a condensate outlet. The arc partition is connected to the vapor phase outlet. The feed distributor b is connected to the dumpling section feed port. The lower part of the cylinder is provided with a reboiler return port. The lower part of the lower head is provided with a tower kettle circulation outlet and a tower kettle discharge port. The heater of the utility model is a built-in tube heater, which is welded to the cylinder through upper and lower fixing plates. Since the above structure belongs to the prior art, the applicant will not repeat it here.

[0008] The core improvements of this utility model are as follows:

[0009] The feed distributor a and the feed distributor b of the utility model have the same structure. The feed distributor a comprises a top fixing plate 2, a bottom fixing plate 2, blades and a connecting plate, wherein the lower part of the top fixing plate 2 is connected to the blades, the blades are connected to the connecting plate, the number of blades is 10-50, and the number of blades can be adjusted according to the size of the equipment. The connecting plate is connected to the bottom fixing plate. The channel of the feed distributor a narrows along the horizontal axis of the tower body, the filler is 2-5 layers, and the upper parts of the feed distributor a and the feed distributor b are provided with a demister a and a demister b, the demister a and the demister b are both wire mesh demisters, the wire mesh material of the wire mesh demister is molybdenum-containing stainless steel resistant to ammonia corrosion, the arc partition is welded on the tower body, and the tower is divided into upper and lower sections, the upper part of the arc partition is a flash section, and the lower part is a distillation section. The top of the arc-shaped partition is connected to the vapor phase outlet pipeline, and a discharge port is arranged at the lower point of the upper part of the arc-shaped partition, and materials are transported to the distillation section at the lower part of the arc-shaped partition through the pipeline.

[0010] The feed distributor is a blade-type distributor, which is connected to the feed pipeline through a flange, and the fixing plate at the bottom of the feed distributor is welded to the tower body.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] The utility model improves the separation efficiency of the distillation section of the ammonia tower by arranging wire mesh structured fillers resistant to ammonia corrosion, and the tower body is designed to be low, the equipment manufacturing cost is low, and the steam consumption is low. Double-layer blade distributors are used at the feed inlets of the flash section and the distillation section to disperse a single strand of material into multiple strands of material, greatly increasing the heating area, prompting ammonia to be quickly desorbed from the mixed material, and further reducing steam consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the internal structure of the utility model.

[0014] Figure 2 This is a three-dimensional diagram of the feed distributor of the utility model structure.

[0015] In the figure: 1. vapor phase outlet at the top of the tower; 2. upper head; 3. demister a; 4. feed inlet; 5. feed distributor; 501. top fixing plate 2; 502. connecting plate; 503. blades; 504. bottom fixing plate 2; 6. steam inlet; 7. condensate outlet; 8. tube heater; 801. top fixing plate; 802. tubes; 803. bottom fixing plate; 9. vapor phase outlet of distillation section; 10. arc partition; 11. bottom liquid outlet of flash section; 12. feed inlet of distillation section; 13. packing; 14. return port of reboiler; 15. cylinder; 16. lower head; 17. skirt; 18. discharge port of tower kettle; 19. circulation outlet of tower kettle; 20. demister b; 21. feed distributor b. DETAILED DESCRIPTION

[0016] like Figure 1 As shown:

[0017] A high-efficiency ammonia distillation tower, comprising an upper end cap 2, a cylinder 22, a lower end cap 16 and a skirt 17, wherein the upper and lower parts of the cylinder 22 are sealed by the upper end cap 2 and the lower end cap 16 respectively, the cylinder 22 is mounted on the skirt 17, the upper part of the upper end cap 2 is provided with a tower top vapor phase outlet 1, the cylinder 22 is provided with a feed distributor a5, a tube heater 8, an arc partition 10, a feed distributor b21 and a filler 13 from top to bottom, the filler 13 is 3 layers, and the feed The distributor a5 is connected to the feed port 4, the upper and lower parts of the tube-in-tube heater 8 are provided with a top fixing plate 801 and a bottom fixing plate 802, the tube-in-tube heater 8 is provided with a steam inlet 6 and a condensate outlet 7, the arc-shaped partition 10 is connected to the vapor phase outlet 9, the feed distributor b21 is connected to the dumpling section feed port 12, the lower part of the cylinder 22 is provided with a reboiler return port 14, and the lower part of the lower head 16 is provided with a tower kettle circulation outlet 19 and a tower kettle discharge port 18.

[0018] like Figure 2 As shown:

[0019] The feed distributor a5 has the same structure as the feed distributor b21. The feed distributor a5 includes a top fixing plate 501, a bottom fixing plate 504, blades 503 and a connecting plate 502. The lower part of the top fixing plate 501 is connected to the blades 503, the blades 503 are connected to the connecting plate 502, and the connecting plate 502 is connected to the bottom fixing plate 504. The channel of the feed distributor a5 is narrowed from wide to narrow along the horizontal axis of the tower body.

[0020] The upper parts of the feed distributor a5 and the feed distributor b21 are provided with demister a3 and demister b20, both of which are wire mesh demisters, and the wire mesh material of the wire mesh demisters is molybdenum-containing stainless steel resistant to ammonia corrosion.

[0021] Two layers of 90-degree arc blades 503 are arranged vertically between the top fixing plate 2 501 and the bottom fixing plate 2 504, with 26 blades. The connecting plate 502 of the two layers of blades is fixed by bolts, and the channel of the entire feed distributor is narrowed from wide along the horizontal axis of the tower body. After the material enters the feed distributor, it is sprayed uniformly from the gap between the blades 503 along the arc of the blades 503 to the surroundings, and the single strand of material is dispersed into multiple strands of material, which greatly increases the heating area, prompts ammonia to be quickly desorbed from the mixed material, and removes the entrained droplets through the demister above. The demister is a stainless steel wire mesh demister that is resistant to ammonia corrosion. The ammonia after defoaming is discharged from the vapor phase outlet 1 at the top of the tower, and the flash heat source required by the material is provided by the built-in tube heater 8 below the feed distributor a5. The material circulates in the tube 802, and the steam enters the tube gap from the steam inlet 6 to heat the material in the tube. The condensed water is discharged from the condensate outlet 7, and fixed plates are set at both ends of the tube. The material from which part of the ammonia has been desorbed is enriched above the arc-shaped partition plate 10 and is transported to the distillation section inlet 12 through the flash section bottom liquid outlet 11 pipeline to enter the distillation section for further separation of ammonia.

[0022] The distillation section is also provided with a feed distributor b21 and an upper demister b20 at the position of the distillation section feed port 12, and the distilled ammonia is discharged from the distillation section vapor phase outlet 9. The lower part of the distillation section feed distributor b21 is filled with three sections of stainless steel wire mesh structured packing 13 resistant to ammonia corrosion, and the gas-liquid two phases are transferred for mass and heat in the packing 13. Compared with the sieve plate used in the traditional ammonia distillation tower, the gas-liquid contact area is larger and the separation efficiency is higher. Therefore, the designed tower body is lower, the equipment manufacturing cost is low, and the steam consumption is low. The material from which most of the ammonia is separated is left in the tower kettle, part of which is returned to the tower from the reboiler return port 14 after being heated by the reboiler from the tower kettle circulation outlet 19, and the other part is discharged from the tower kettle discharge port 18 to the next section for further processing.

Claims

1. A high-efficiency ammonia distillation tower, comprising an upper end cap (2), a cylinder (22), a lower end cap (16) and a skirt (17), wherein the upper and lower parts of the cylinder (22) are sealed by the upper end cap (2) and the lower end cap (16) respectively, the cylinder (22) is mounted on the skirt (17), the upper part of the upper end cap (2) is provided with a tower top vapor phase outlet (1), the cylinder (22) is provided with a feed distributor a (5), a tube heater (8), an arc-shaped partition (10), a feed distributor b (21) and a filler (13) in sequence from top to bottom, the feed distributor a (5 ) is connected to the feed port (4), the upper and lower parts of the tube heater (8) are provided with a top fixing plate (801) and a bottom fixing plate (802), the tube heater (8) is provided with a steam inlet (6) and a condensate outlet (7), the arc-shaped partition (10) is connected to the vapor phase outlet (9), the feed distributor b (21) is connected to the dumpling section feed port (12), the lower part of the cylinder (22) is provided with a reboiler return port (14), the lower part of the lower head (16) is provided with a tower kettle circulation outlet (19) and a tower kettle discharge port (18), characterized in that, The feed distributor a (5) and the feed distributor b (21) have the same structure. The feed distributor a (5) includes a top fixing plate 2 (501), a bottom fixing plate 2 (504), blades (503) and a connecting plate (502), wherein the lower part of the top fixing plate 2 (501) is connected to the blades (503), the blades (503) are connected to the connecting plate (502), and the connecting plate (502) is connected to the bottom fixing plate 2 (504).

2. A high-efficiency ammonia distillation tower as claimed in claim 1, characterized in that: The channel of the feed distributor a (5) is narrowed along the horizontal axis of the tower body.

3. A high-efficiency ammonia distillation tower as claimed in claim 1, characterized in that: The filler (13) has 2 to 5 layers.

4. A high-efficiency ammonia distillation tower as claimed in claim 1, characterized in that: The upper parts of the feed distributor a (5) and the feed distributor b (21) are provided with a demister a (3) and a demister b (20), and the demister a (3) and the demister b (20) are both wire mesh demisters.

5. A high-efficiency ammonia distillation tower as claimed in claim 4, characterized in that: The wire mesh material of the wire mesh demister is molybdenum-containing stainless steel resistant to ammonia corrosion.

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