Bubble-cap tower for wet-process phosphoric acid defluorination

Abstract

The utility model relates to the technical field of wet-process phosphoric acid defluorination equipment, in particular to a bubble cap tower for wet-process phosphoric acid defluorination, which comprises a tower body, a plurality of layers of tower plates arranged in the tower body from top to bottom, a plurality of bubble caps mounted on the tower plates, a steam outlet arranged at the top of the tower body, and an acid inlet arranged above the topmost tower plate. An acid outlet is formed in one side of the lower part of the tower body, a downcomer is arranged on each layer of tower plate in a penetrating manner, the upper downcomer and the lower downcomer are respectively arranged on two sides of the upper layer of tower plate and the lower layer of tower plate, a partition plate is arranged above the acid outlet, a liquid seal pipe is arranged on the partition plate, and a steam ring pipe and a steam inlet pipe are arranged above the partition plate. By arranging the downcomer, the arrangement of a tower plate overflow weir is canceled, so that the deposition and scaling of sediments are reduced, and the tower plate is convenient to clean; by arranging the liquid seal pipe, the upper air pressure of the tower body is stabilized, and fluctuation is avoided; phosphoric acid is indirectly heated through the steam ring pipe and directly heated through the steam inlet pipe, vibration of steam entering the pipeline is reduced, and the heat exchange efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to wet process phosphoric acid defluorination equipment technical field, specifically, relate to a wet process phosphoric acid defluorination is with bubble cap tower. BACKGROUND

[0002] At present, wet process phosphoric acid mainly adopts dihydrate method production process, specifically, phosphorite and sulfuric acid carry out the reaction in extraction tank, after extraction, the concentration of phosphoric acid is generally between 22%-25% in P2O5, then after concentration and impurity removal, get finished product phosphoric acid. The fluorine content in wet process phosphoric acid is relatively high, generally removes fluorine in phosphoric acid through defluorination process, and the existing defluorination technology mainly adopts defluorination tower stripping defluorination, and the defluorination tower has various forms, wherein the bubble cap tower is applied more. The phosphoric acid of the traditional bubble cap tower enters the next tray through the overflow weir on the tray, but also causes the sediment to deposit on the tray, which is not convenient to clean, and increases the operation and maintenance cost of the bubble cap tower. SUMMARY

[0003] The utility model discloses a wet process phosphoric acid defluorination bubble cap tower to solve the problem of inconvenient cleaning and high operation and maintenance cost of the defluorination bubble cap tower in the traditional wet process phosphoric acid process.

[0004] To achieve the above object, the utility model provides a wet process phosphoric acid defluorination bubble cap tower, including the tower body, its characterized in that: the inside of the tower body is provided with a plurality of layers of tower plates from top to bottom, a plurality of bubble caps are installed on the tower plate, the top of the tower body is provided with a steam outlet, the top of the topmost tower plate is provided with an acid inlet, the lower part of the tower body is provided with an acid outlet on one side, a downcomer is provided on each tower plate, and the upper and lower downcomers are provided on the two sides of the upper and lower tower plates respectively. The side wall of the tower body close to each tower plate is provided with a liquid outlet, a baffle is provided above the acid outlet, a liquid seal pipe is arranged on the baffle, a steam ring pipe and a steam inlet pipe are arranged above the baffle, a steam inlet is arranged on the tower body, the steam inlet is connected with the steam ring pipe and the steam inlet pipe through a pipeline, and the steam ring pipe is connected with a steam recovery device.

[0005] Preferably, the liquid seal pipe comprises an inner pipe, the inner pipe penetrates the baffle, a sleeve pipe is arranged on the outer side of the lower end of the inner pipe, the sleeve pipe is open at the top, the bottom of the inner pipe is provided with an inclined opening, and the outer side wall of the sleeve pipe is fixed on the inner wall of the tower body.

[0006] Preferably, the distance between the downcomer and the tower plate is 120-180mm, and the distance between the lower end of the downcomer and the next layer of tower plate is 50-80mm.

[0007] As preferred, the middle part of the downcomer is provided with a first external thread, two first threaded rings are mounted on the first external thread, the two first threaded rings are arranged on the upper and lower sides of the tray respectively, and first sealing washers are arranged between the two first threaded rings and the tray.

[0008] As preferred, the middle part of the downcomer is provided with a first external thread, two first threaded rings are mounted on the first external thread, the two first threaded rings are arranged on the upper and lower sides of the tray respectively, and first sealing washers are arranged between the two first threaded rings and the tray.

[0009] Compared with the prior art, the present application has the following beneficial effects:

[0010] In the wet-process phosphoric acid defluorination bubble column, the downcomer is arranged to cancel the arrangement of the overflow weir of the tray, reduce the deposition and scaling of the sediment, and facilitate the cleaning of the tray; the liquid seal pipe is arranged to stabilize the gas pressure of the upper part of the tower body and avoid fluctuations; the steam ring pipe indirectly heats the phosphoric acid, and the steam inlet pipe directly heats the phosphoric acid, which can reduce the vibration of the steam entering the pipeline, improve the heat exchange efficiency, and improve the defluorination efficiency.

[0011] The position of the downcomer is limited, and it is fixed by passing through two threaded rings, which facilitates disassembly during cleaning and improves the cleaning efficiency; and the liquid seal pipe is arranged in the inner pipe and the sleeve pipe, so that the phosphoric acid flows out from the sleeve pipe after entering the inner pipe, realizes liquid sealing, and stabilizes the gas pressure of the upper part of the tower body in the stripping defluorination area, avoiding the influence of gas pressure fluctuations on the defluorination effect. BRIEF DESCRIPTION OF DRAWINGS

[0012] Fig. 1 It is a schematic diagram of the overall structure of the present application;

[0013] Fig. 2 It is a schematic diagram of the structure of the downcomer in the present application;

[0014] Fig. 3 It is a schematic diagram of the structure of the liquid seal pipe in the present application;

[0015] The meanings of the various reference numbers in the drawings are as follows:

[0016] 1, tower body; 11, steam inlet; 12, steam outlet; 13, acid inlet; 14, acid outlet; 2, tray; 3, bubble; 4, downcomer; 41, first external thread; 42, first threaded ring; 43, first sealing washer; 5, liquid seal pipe; 51, inner pipe; 511, second external thread; 512, second threaded ring; 513, second sealing washer; 514, bevel; 52, sleeve pipe; 6, liquid outlet; 7, partition; 8, steam inlet pipe. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] The utility model provides a bubble tower for wet-process phosphoric acid defluorination, such as Figs. 1-3 As shown, it includes a tower body 1, wherein a plurality of tower plates 2 are horizontally installed from top to bottom inside the tower body 1, and a plurality of bubble caps 3 are densely distributed on the tower plates 2. A steam outlet 12 is provided on the top of the tower body 1, and the steam outlet 12 is connected to an exhaust gas treatment device to absorb the fluorine in the exhaust gas and then recycle or empty it. An acid inlet 13 is provided above the topmost tower plate 1, and a downcomer 4 is provided on each tower plate 2. The upper and lower downcomers 4 are staggered on the left and right sides of the upper and lower tower plates 2. A liquid outlet 6 is provided on the side wall of the tower body 1 near each tower plate 2, and an acid outlet 14 is provided on one side of the lower part of the tower body 1. A liquid seal pipe 5 is provided on the partition 7, and a steam ring pipe and a steam inlet pipe are provided above the partition 7. A steam inlet 11 is provided on the tower body 1, and the steam inlet 11 is connected to the steam ring pipe and the steam inlet pipe 8 respectively through pipes. The steam ring pipe is serpentine or spirally arranged below the phosphoric acid liquid level in the partition 7, and its outlet is connected to the steam recovery device.

[0019] During defluorination, fluorinated phosphoric acid enters the tower body 1 through the acid inlet 13, overflows from the topmost tray 2 through the downcomer 4 into the lower tray 2, and is temporarily stored on the partition 7. High-temperature steam indirectly heats the phosphoric acid through the steam loop. The steam inlet directly heats the phosphoric acid and then flows upward through the bubble cap 3 into the phosphoric acid on the tray 2, heating it there. This causes the fluorine to escape as a gas, achieving the defluorination goal. The purified phosphoric acid is temporarily stored on the partition 7, where steam heating further releases fluorinated gases. When the liquid level reaches a certain height, it overflows through the liquid seal tube 5 into the acid storage space below the partition 7, and is finally withdrawn from the acid outlet 14 to enter the next process step.

[0020] In order to prevent the gas in the stripping defluorination space above the partition 7 from entering the acid storage space below, and also to maintain the air pressure in the stripping defluorination space above the partition 7 stable, the liquid seal tube 5 includes an inner tube 51, which passes through the partition 7. The lower end of the inner tube 51 is sheathed with a sleeve 52 on the outside. The top of the sleeve 52 is open, and the bottom of the inner tube 51 is provided with an oblique opening 514. The outer wall of the sleeve 52 is fixed to the inner wall of the tower body 1. The inner tube 51 is higher than the partition 7, and the top of the sleeve 52 is below the partition 7. After defluorination, phosphoric acid enters the sleeve 52 from the inner tube 51 and overflows into the acid storage space below the partition 7. During this process, the gas above the partition 7 is difficult to enter, which effectively achieves the effect of maintaining the defluorination pressure stable and preventing the air pressure fluctuation from affecting the defluorination effect.

[0021] In order to control the liquid level on the tray, the distance between the downcomer 4 and the tray 2 is 120-180mm, and the distance between the lower end of the downcomer 4 and the next tray 2 is 50-80mm.

[0022] In order to facilitate the installation and cleaning of the downcomer, the middle part of the downcomer 4 is provided with a first external thread 41, and two first threaded rings 42 are installed on the first external thread 41, and the two first threaded rings 42 are respectively arranged on the upper and lower sides of the tray 2, and a first sealing gasket 43 is arranged between the two first threaded rings 42 and the tray 2, and the downcomer 4 is sealed and installed on the tray 2 through the two first threaded rings 42 and the first sealing gasket 43, and when cleaning is needed or when maintenance and replacement are needed, the downcomer 4 can also be quickly disassembled and assembled, which greatly improves the cleaning efficiency.

[0023] Similarly, in order to facilitate the installation of the inner tube of the liquid seal pipe, the middle part of the inner tube 51 is provided with a second external thread 511, and two second threaded rings 512 are installed on the second external thread 511, and the two second threaded rings 512 are respectively arranged on the upper and lower sides of the tray 2, and a second sealing gasket 513 is arranged between the two second threaded rings 512 and the tray 2.

[0024] The basic principle, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present application and do not limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A wet-process phosphoric acid defluorination bubble column comprising a column body (1), characterized in that: The inside of the tower body (1) is provided with a plurality of layers of tower plates (2) from top to bottom, a plurality of bubble caps (3) are installed on the tower plates (2), the tower body (1) is provided with a steam outlet (12) at the top, an acid inlet (13) is arranged above the top layer of tower plates (2), an acid outlet (14) is arranged at one side of the lower part of the tower body (1), a downcomer (4) is arranged through each layer of tower plates (2), two downcomers (4) are arranged on the two sides of the upper and lower layers of tower plates (2) respectively, a liquid outlet (6) is arranged on the side wall of the tower body (1) close to each layer of tower plates (2), a partition plate (7) is arranged above the acid outlet (14), a liquid seal pipe (5) is arranged on the partition plate (7), a steam ring pipe and a steam inlet pipe are arranged above the partition plate (7), a steam inlet (11) is arranged on the tower body (1), the steam inlet (11) is connected with the steam ring pipe and the steam inlet pipe (8) through pipelines, and the steam ring pipe is connected with a steam recovery device.

2. The wet process phosphoric acid defluorination bubble column according to claim 1, characterized in that: The liquid seal pipe (5) comprises an inner pipe (51), the inner pipe (51) penetrates the partition plate (7), a sleeve pipe (52) is arranged on the outer side of the lower end of the inner pipe (51), the sleeve pipe (52) is open at the top, and the bottom of the inner pipe (51) is provided with an inclined opening (514), and the outer side wall of the sleeve pipe (52) is fixed on the inner wall of the tower body (1).

3. The wet process phosphoric acid defluorination bubble column according to claim 1, characterized in that: The distance between the downcomer (4) and the layer of tower plates (2) is 120-180mm, and the distance between the lower end of the downcomer (4) and the next layer of tower plates (2) is 50-80mm.

4. The wet process phosphoric acid defluorination bubble column according to claim 1, characterized in that: The middle part of the downcomer (4) is provided with a first external thread (41), two first threaded rings (42) are installed on the first external thread (41), the two first threaded rings (42) are arranged on the upper and lower sides of the tower plate (2) respectively, and a first sealing gasket (43) is arranged between the two first threaded rings (42) and the tower plate (2).

5. The wet process phosphoric acid defluorination bubble column according to claim 2, characterized in that: The middle part of the inner pipe (51) is provided with a second external thread (511), two second threaded rings (512) are installed on the second external thread (511), the two second threaded rings (512) are arranged on the upper and lower sides of the tower plate (2) respectively, and a second sealing gasket (513) is arranged between the two second threaded rings (512) and the tower plate (2).

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