Cooling structure of phosphoric acid combustion tower

Abstract

The invention discloses a cooling structure of a phosphoric acid combustion tower, which belongs to the field of chemical energy equipment engineering, and is characterized in that an upper ring pipe is arranged on an upper seal head of the combustion tower, a lower ring pipe is arranged on a lower seal head of the combustion tower, a double-layer cooling channel is arranged outside a barrel, and a second cooling channel is used for filling a cooling gap of a first cooling channel at a connecting sheet; the cooling water inlet is formed in the lower portion, the cooling water outlet is formed in the upper portion, cooling water rapidly enters and fills the round pipes and the semi-circle pipes under high pressure, the purposes of rapid cooling and heat absorption are achieved, heat recovery is greatly improved, and economical and practical effects are achieved. The two layers of cooling channels are located on the outer side of the barrel, cooling water pollution caused by breakage of the cooling channels is avoided, and maintenance is more convenient. And the two layers of cooling pipes can enhance the strength of the cylinder, so that the cylinder is not easy to deform, and the service life of equipment is prolonged.

Description

Technical Field

[0001] The invention relates to the field of chemical energy equipment engineering, in particular to a cooling structure of a phosphoric acid combustion tower. Background Art

[0002] In the phosphoric acid production process, the role of the combustion tower is to spray liquid yellow phosphorus into the tower through a special spray gun at high temperature, use compressed air for pressurization, and inhale natural air to burn in the combustion tower. The high temperature generated by the reaction must be fully cooled. The existing method is to set the tower body of the combustion tower into a tube-in-tube structure, that is, a layer of cooling pipes is vertically arranged along the inner wall of the tower body. This type of cooling structure has a certain distance of space between each adjacent cooling pipe, that is, the cooling surface does not completely cover the circumference of the cylinder body, resulting in the inability to cool the filter connecting plate between the tubes and the tubes, which is in a high temperature state for a long time. In addition, the cooling pipes are easy to rupture, and the cooling water will enter the tower and mix with the phosphoric acid, polluting the phosphoric acid. It is also very difficult to repair, which seriously affects the continuity of production. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a cooling structure for a phosphoric acid combustion tower. By arranging two layers of cooling pipes outside the cylinder, the cooling area of ​​the cylinder reaches 100%, which not only increases the cooling area, greatly improves heat recovery, and is economical and practical. The cooling pipes are arranged outside the combustion tower, which also solves the problems of cooling water pollution and maintenance difficulties. The double-layer cooling pipes also increase the strength of the cylinder and extend the service life of the combustion tower.

[0004] In order to solve the above technical problems, the present invention provides a cooling structure of a phosphoric acid combustion tower, comprising a combustion tower, wherein the combustion tower comprises an upper end cap, a cylinder and a lower end cap, wherein a circle of upper annular tubes is fixed at the connection between the upper end cap and the cylinder, and a plurality of steam riser pipe openings are arranged on the upper annular tube; a circle of lower annular tubes is fixed at the connection between the lower end cap and the cylinder, and a plurality of cooling water inlets are arranged on the lower annular tube; a circle of circular tubes is arranged vertically at intervals on the outer side of the cylinder, and adjacent circular tubes are connected and fixed by connecting plates, and the upper and lower ends of the circular tubes are respectively connected with the upper annular tube and the lower annular tube to form a first layer of cooling channels; a semicircular tube is fixed between every two adjacent circular tubes, and the upper and lower ends of the semicircular tubes are also respectively connected with the upper annular tube and the lower annular tube to form a second layer of cooling channels.

[0005] When the combustion tower needs to be cooled, the cooling water enters the lower ring tube from the cooling water inlet. After exchanging heat with the combustion tower through the first and second cooling channels, part of the cooling water is heated to become water vapor. The water vapor and the hot cooling water that absorbs a certain amount of heat are discharged from the steam riser on the upper ring tube to the steam drum, realizing heat recovery and reuse. The second cooling channel fills the cooling gap of the first cooling channel, so that the cooling surface of the cylinder reaches 100%. In addition, the cooling water inlet is set at the bottom and the steam riser is set at the top. The cooling water enters quickly under high pressure and fills the round tube and half-circle tube, achieving the purpose of rapid cooling and heat absorption. The steam rises and can be discharged smoothly from the steam riser. The two layers of cooling channels are located outside the cylinder to avoid cooling water pollution caused by the rupture of the cooling pipe, and it is more convenient to maintain. The two layers of cooling pipes can also increase the strength of the cylinder, making it less likely to deform and extending the service life of the equipment.

[0006] As a further description of the above technical solution, the upper head is a conical head, the inner cavity of the upper head is connected to the inner cavity of the phosphoric acid combustion tower, and the outer wall of the upper head is fixed with a water inlet semicircular pipe and a water outlet semicircular pipe that are close to the outer wall of the upper head and run up and down. The water inlet semicircular pipe and the water outlet semicircular pipe are arranged closely, and a water inlet A is provided on the water inlet semicircular pipe, and a steam outlet is provided on the water outlet semicircular pipe. Several circles of semicircular annular pipes A surrounding the outer wall of the upper head are laid between the water inlet semicircular pipe and the water outlet semicircular pipe, and the two ends of the semicircular annular pipe A are respectively connected to the water inlet semicircular pipe and the water outlet semicircular pipe, and the semicircular annular pipe A is close to the outer wall of the upper head, and a first cooling channel of the upper head is formed between the semicircular annular pipe A and the outer wall of the upper head. When the combustion tower is working, due to the rise of hot air, the temperature at the upper head is even higher than the temperature in the middle of the cylinder. Therefore, it is particularly necessary to cool the upper head. A water inlet semicircular pipe and a water outlet semicircular pipe are arranged on the outer wall of the upper head, and a semicircular ring pipe A is laid to form a first cooling channel of the upper head on the outer wall of the upper head, which effectively reduces the temperature at the upper head, improves the safety of the combustion tower, and extends the service life of the combustion tower; the steam outlet on the water outlet semicircular pipe is connected to the steam drum, and the cooling water after heat exchange is at a high temperature or is partially vaporized into water vapor. The hot cooling water and steam are sent to the steam drum and can be collected and reused.

[0007] As a further description of the above technical solution, a semicircular annular tube B is stacked between every two adjacent semicircular annular tubes A, and the two ends of the semicircular annular tube B are also respectively connected to the water inlet semicircular tube and the water outlet semicircular tube. A second cooling channel of the upper head is formed between the semicircular annular tube B and the semicircular annular tube A. The second cooling channel of the upper head can fill the cooling gap of the first cooling channel of the upper head, thereby improving the cooling effect of the upper head.

[0008] As a further description of the above technical solution, a water inlet B is also provided on the water inlet semicircular pipe. Because under normal circumstances, the upper head of the combustion tower is large in volume and the water inlet speed of one water inlet is limited, it may be difficult to achieve the purpose of rapid cooling. Two water inlets are set to allow water to enter at the same time, thereby increasing the cooling water flow rate and achieving the purpose of rapid cooling.

[0009] As a further description of the above technical solution, a process exhaust port is provided on the top of the upper head, an exhaust pipe is connected to the process exhaust port, an exhaust pipe is provided outside the exhaust pipe, a circulating water inlet and a circulating water outlet are provided on the exhaust pipe jacket, and the process exhaust port is used to discharge the high-temperature gas generated during combustion in the combustion tower to prevent accidents such as tower explosion due to excessive pressure in the combustion tower. When the high-temperature gas is discharged through the exhaust pipe, in order to avoid damage to the exhaust pipe caused by high temperature, an exhaust pipe jacket is installed outside the exhaust pipe, and the exhaust pipe wall is cooled by circulating water.

[0010] As a further description of the above technical solution, the lower head is a butterfly head, the inner cavity of the lower head is isolated from the inner cavity of the phosphoric acid combustion tower, and the lower head is provided with a lower head water inlet and a lower head water outlet. When the combustion tower is burning, the heat generated may damage the lower head. The lower head is provided with circulating cooling, which can effectively reduce the problem of the lower head, prevent the lower head from being damaged, and extend the service life of the combustion tower.

[0011] As a further description of the above technical solution, the diameter of the upper annular tube is greater than the diameter of the circular tube, the diameters of the circular tube, the semicircular tube and the annular semicircular tube are all the same, and the diameter of the upper annular tube is the same as that of the lower annular tube. Since the circular tube and the semicircular tube are both connected to the upper annular tube and the lower annular tube, the cooling water in the lower annular tube fills the circular tube and the semicircular tube under high pressure, and the cooling water in the circular tube and the semicircular tube enters and fills the upper annular tube under high pressure and is discharged from the cooling water outlet of the upper annular tube, which requires the upper annular tube and the lower annular tube to have an inner diameter larger than that of the circular tube and the semicircular tube to ensure the cooling water flow in the circular tube and the semicircular tube and to meet the needs.

[0012] As a further description of the above technical solution, the circular tube, semicircular tube, semicircular ring tube A and semicircular ring tube B are all seamless steel tubes. The use of seamless steel tubes can avoid cracking at the joints, avoid cooling water leakage from the joints, and extend the service life of the entire combustion tower.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0014] By setting an upper ring tube on the upper end of the combustion tower, setting a lower ring tube on the lower end, and setting a double-layer cooling channel outside the cylinder, the second cooling channel fills the cooling gap left by the first cooling channel at the connecting piece, so that the cooling area of ​​the cylinder reaches 100%, and the cooling water inlet is set at the bottom and the cooling water outlet is set at the top. The cooling water enters quickly through high pressure and fills the round tube and half-circle tube, achieving the purpose of rapid cooling and heat absorption, and greatly improving heat recovery, which is economical and practical. Both layers of cooling channels are located outside the cylinder to avoid cooling water pollution caused by rupture of the cooling pipe, and maintenance is also more convenient. The two layers of cooling pipes can also increase the strength of the cylinder, making the cylinder less likely to deform and extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the cooling structure of the phosphoric acid combustion tower of the present invention.

[0016] Figure 2 yes Figure 1 AA section view.

[0017] Figure 3 yes Figure 2 Enlarged view of part B in the middle.

[0018] Figure 4 yes Figure 1 Enlarged view of part C in the middle.

[0019] Figure 5 It is a top view of the upper head.

[0020] Figure 6 yes Figure 5 DD cross-sectional view.

[0021] Figure 7 It is a schematic diagram of the positional relationship between the water inlet semicircular pipe and the semicircular ring pipe A and the semicircular ring pipe B.

[0022] Figure 8 It is a top view of the phosphoric acid combustion tower of the present invention.

[0023] Legend:

[0024] 10. Upper head; 11. Water inlet semicircular pipe; 12. Water outlet semicircular pipe; 13. Water inlet A; 14. Water inlet B; 15. Steam outlet; 16. Semicircular ring pipe A; 17. Semicircular ring pipe B; 20. Cylinder; 21. Round pipe; 22. Connecting piece; 23. Semicircular pipe; 30. Lower head; 31. Lower head water inlet; 32. Lower head water outlet; 40. Upper ring pipe; 41. Steam riser pipe; 50. Lower ring pipe; 51. Cooling water inlet; 61 Exhaust pipe; 62. Exhaust pipe jacket; 63. Circulating water inlet. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] A cooling structure for a phosphoric acid combustion tower, such as Figure 1 — Figure 8 As shown, the combustion tower includes an upper end cap 10, a cylinder 20 and a lower end cap 30. The cylinder 20 is a cylindrical body of Φ3600*12000*10. A circle of upper annular tubes 40 are fixed at the connection between the upper end cap 10 and the cylinder 20. The upper annular tube 40 is a Φ219 circular tube. A plurality of steam riser ports 41 are provided on the upper annular tube 40. The steam riser ports 41 are connected to the steam drum and are used to collect the discharged hot steam and the hot cooling water for heat exchange into the steam drum for reuse; a circle of lower annular tubes 50 are fixed at the connection between the lower end cap 30 and the cylinder 20. The lower annular tube 50 is also a Φ219 circular tube. A plurality of cooling water inlets 51 are provided on the lower annular tube 50; a circle of circular tubes 41 are arranged vertically at intervals on the outer side of the cylinder 20. Tube 21, the round tube 21 is a Φ76 seamless steel tube, there are 106 round tubes 21 in total, which are wound around the cylinder 12 for one week, and the adjacent round tubes 21 are welded and fixed by connecting pieces 22. The upper and lower ends of the round tube 21 are respectively connected with the upper ring tube 40 and the lower ring tube 50 to form a first layer of cooling channel; a semicircular tube 23 is fixed between every two adjacent round tubes 21, and the semicircular tube 23 is also a Φ76 seamless steel tube. There are 106 semicircular tubes 23 in total, and the upper and lower ends of the semicircular tube 23 are also respectively connected with the upper ring tube 40 and the lower ring tube 50 to form a second layer of cooling channel. The second cooling channel can fill the area not covered by cooling water at the connecting piece 22, so that the cooling area of ​​the cylinder reaches 100%. When the combustion tower is burning, cooling water first enters the lower ring tube 50 from the multiple cooling water inlets 51 of the lower ring tube 50, and quickly fills the first layer cooling channel and the second layer cooling channel under pressure to exchange heat with the combustion tower. Part of the cooling water is heated to become hot water vapor, and the hot water vapor and the hot cooling water that absorbs a certain amount of heat are discharged from the steam riser port 41 on the upper ring tube 40 to the steam drum, realizing heat recovery and reuse. The second layer cooling channel fills the cooling gap of the first layer cooling channel, so that the cooling surface of the cylinder reaches 100%, and the cooling water inlet 51 is arranged at the bottom and the steam riser port 41 is arranged at the top. The cooling water quickly enters and fills the round tube 21 and the half-circle tube 23 through high pressure, achieving the purpose of rapid cooling and heat absorption, and the steam rises and can be smoothly discharged from the steam riser port 41. Both layers of cooling channels are located outside the cylinder 20, avoiding cooling water pollution caused by the rupture of the cooling pipe, and it is more convenient to repair. The two layers of cooling pipes can also increase the strength of the cylinder, making the cylinder not easy to deform, and extending the service life of the equipment.

[0027] As a preferred embodiment of the present invention, the upper head 10 is a conical upper head, the inner cavity of the upper head 10 is communicated with the inner cavity of the phosphoric acid combustion tower, and the outer wall of the upper head 10 is fixed with a water inlet semicircular pipe 11 and a water outlet semicircular pipe 12 which are close to the outer wall of the upper head 10 and run up and down. The water inlet semicircular pipe 11 and the water outlet semicircular pipe 12 are arranged closely, and the water inlet semicircular pipe 11 and the water outlet semicircular pipe 12 are both Φ219 semicircular pipes; the water inlet semicircular pipe 11 is provided with a DN50 water inlet A13 and a DN50 water inlet B 14, a DN100 steam outlet 15 is provided on the water outlet semicircular pipe 12, and a plurality of circles of semicircular annular pipes A16 surrounding the outer wall of the upper head are laid between the water inlet semicircular pipe 11 and the water outlet semicircular pipe 12. The semicircular annular pipe A16 is a Φ76 seamless annular pipe, and the two ends of the semicircular annular pipe A16 are respectively connected with the water inlet semicircular pipe 11 and the water outlet semicircular pipe 12. The semicircular annular pipe A16 is tightly attached to the outer wall of the upper head 10, and forms a first cooling channel of the upper head with the outer wall of the upper head 10. A semicircular annular tube B17 is stacked between every two adjacent semicircular annular tubes A16. The semicircular annular tube B17 is also a Φ76 seamless annular tube. The two ends of the semicircular annular tube B17 are also connected to the water inlet semicircular tube 11 and the water outlet semicircular tube 12 respectively. A second cooling channel of the upper head is formed between the semicircular annular tube B17 and the semicircular annular tube A16. The second cooling channel of the upper head can fill the cooling gap of the first cooling channel of the upper head, thereby improving the cooling effect of the upper head. When the combustion tower is working, due to the rise of hot air, the temperature at the upper head 10 is even higher than the temperature in the middle of the cylinder 20. Therefore, it is particularly necessary to cool the upper head 10. A water inlet semicircular pipe 11 and a water outlet semicircular pipe 12 are arranged on the outer wall of the upper head 10, and a semicircular annular pipe A16 and a semicircular annular pipe B17 are laid. The first cooling channel of the upper head and the second cooling channel of the upper head are formed on the outer wall of the upper head 10, which effectively reduces the temperature of the upper head, improves the safety of the combustion tower, and extends the service life of the combustion tower; the steam outlet 15 is connected to the steam drum, and the cooling water after heat exchange has a high temperature or is partially vaporized into water vapor. The hot cooling water and steam are sent to the steam drum and can be collected and reused.

[0028] As another preferred embodiment of the present invention, a process exhaust port is provided on the top of the upper head 10, and an exhaust pipe 61 is connected to the process exhaust port. An exhaust pipe jacket 62 is provided outside the exhaust pipe 61, and a DN100 circulating water inlet 63 and a DN100 circulating water outlet are provided on the exhaust pipe jacket 62. The process exhaust port is used to discharge the high-temperature gas generated during combustion in the combustion tower to prevent safety accidents such as tower explosion due to excessive pressure in the combustion tower. When the high-temperature gas is discharged through the exhaust pipe, in order to avoid damage to the exhaust pipe due to high temperature, an exhaust pipe jacket 62 is installed outside the exhaust pipe 61, and the exhaust pipe 61 is cooled by circulating water.

[0029] As another preferred embodiment of the present invention, the lower end cap 30 is a butterfly end cap, the inner cavity of the lower end cap 30 is isolated from the inner cavity of the phosphoric acid combustion tower, and the lower end cap 30 is provided with a DN100 lower end cap water inlet 31 and a DN100 lower end cap water outlet 32. When the combustion tower is burning, the high temperature generated may damage the lower end cap 30. The lower end cap 30 is provided with a circulating cooling system, which can effectively prevent the lower end cap 30 from being damaged and extend the service life of the combustion tower.

[0030] The cooling structure of the phosphoric acid combustion tower of the present invention is provided with a near-sighted semicircular tube 11, a water outlet semicircular tube 12, a semicircular annular tube A16 and a semicircular annular tube B16 on the upper end cap 10 of the combustion tower, so that the cooling area of ​​the upper end cap 10 reaches 100%; the double-layer cooling channel is provided on the cylinder 20, so that the cylinder cooling area also reaches 100%, and the cooling water inlet 51 is provided at the bottom, and the steam riser pipe 41 is provided at the top, and the cooling water enters and fills the circular tube 21 and the semicircular tube 23 quickly through high pressure, so as to achieve the purpose of rapid temperature reduction and heat absorption. The two layers of cooling channels are both located outside the cylinder 20, so as to avoid the cooling water pollution caused by the rupture of the cooling pipeline, and it is also more convenient to maintain. The two layers of cooling pipes can also increase the strength of the cylinder 20, so that the cylinder 20 is not easily deformed, and the service life of the equipment is extended.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. A person skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the present invention.

Claims

1. A cooling structure for a phosphoric acid combustion tower, comprising a combustion tower, wherein the combustion tower comprises an upper end cap (10), a cylinder (20) and a lower end cap (30), characterized in that: A circle of upper annular tubes (40) is fixed at the connection between the upper end cover (10) and the cylinder (20), and a plurality of steam riser ports (41) are arranged on the upper annular tube (40); a circle of lower annular tubes (50) is fixed at the connection between the lower end cover (30) and the cylinder (20), and a plurality of cooling water inlets (51) are arranged on the lower annular tube (50); a circle of circular tubes (21) are arranged vertically at intervals on the outside of the cylinder (20), and adjacent circular tubes (21) are connected and fixed by connecting plates (22), and the upper and lower ends of the circular tubes (21) are respectively connected to the upper annular tube (40) and the lower annular tube (50), forming a first layer of cooling channels; a semicircular tube (23) is fixed between every two adjacent circular tubes (21), and the upper and lower ends of the semicircular tube (23) are also respectively connected to the upper annular tube (40) and the lower annular tube (50), forming a second layer of cooling channels.

2. The cooling structure of the phosphoric acid combustion tower according to claim 1, characterized in that: The upper end cap (10) is a conical end cap, the inner cavity of the upper end cap (10) is communicated with the inner cavity of the phosphoric acid combustion tower, the outer wall of the upper end cap (10) is fixed with a water inlet semicircular pipe (11) and a water outlet semicircular pipe (12) which are closely attached to the outer wall of the upper end cap and run in an up-and-down direction, the water inlet semicircular pipe (11) and the water outlet semicircular pipe (12) are arranged closely, the water inlet semicircular pipe (11) is provided with a water inlet A (13), and the water outlet semicircular pipe (12) is provided with a steam outlet (15), a plurality of semicircular annular tubes A (16) surrounding the outer wall of the upper head (10) are laid between the water inlet semicircular tube (11) and the water outlet semicircular tube (11), the two ends of the semicircular annular tube A (16) are respectively connected to the water inlet semicircular tube (11) and the water outlet semicircular tube (12), the semicircular annular tube A (16) is tightly attached to the outer wall of the upper head (10), and a first cooling channel of the upper head is formed between the semicircular annular tube A (16) and the outer wall of the upper head (10).

3. The cooling structure of the phosphoric acid combustion tower as claimed in claim 2, characterized in that: A semicircular annular tube B (17) is stacked between every two adjacent semicircular annular tubes A (16), and both ends of the semicircular annular tube B (17) are also respectively connected to the water inlet semicircular tube (11) and the water outlet semicircular tube (12), and a second cooling channel of the upper head is formed between the semicircular annular tube B (17) and the semicircular annular tube A (16).

4. The cooling structure of the phosphoric acid combustion tower according to claim 2 or 3, characterized in that: The water inlet semicircular pipe (11) is also provided with a water inlet B (14).

5. The cooling structure of the phosphoric acid combustion tower according to claim 2 or 3, characterized in that: The top of the upper head (10) is provided with a process exhaust port, which is connected to an exhaust pipe (61). An exhaust pipe jacket (62) is provided outside the exhaust pipe (61), and a circulating water inlet (63) and a circulating water outlet are provided on the exhaust pipe jacket (62).

6. The cooling structure of the phosphoric acid combustion tower according to claim 1, characterized in that: The lower end cap (30) is a butterfly-shaped end cap, the inner cavity of the lower end cap (30) is isolated from the inner cavity of the phosphoric acid combustion tower, and the lower end cap (30) is provided with a lower end cap water inlet (31) and a lower end cap water outlet (32).

7. The cooling structure of the phosphoric acid combustion tower according to claim 3, characterized in that: The circular tube (21), the semicircular tube (23), the semicircular ring tube A (16) and the semicircular ring tube B (17) are all seamless steel tubes.

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