Multistage rectifying tower for refining yellow phosphorus
By adopting a lower overhead distribution cap and angled guide plate design in the multi-stage distillation column for yellow phosphorus refining, the problems of insufficient gas-liquid contact interface and heat exchange are solved, achieving efficient yellow phosphorus separation and reduced energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YUNNAN XUDONG GRP CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-12
AI Technical Summary
In existing multi-stage distillation columns for yellow phosphorus refining, the gas-liquid contact interface and heat exchange area of the trays are insufficient, resulting in low separation efficiency, inability to effectively remove impurities, and high energy consumption. Furthermore, traditional tray designs suffer from localized uneven gas velocity and uneven liquid distribution.
The design employs a distribution cap with a lower part that is suspended and has dense openings on the surface, as well as a bendable guide plate, to form a double-layer contact structure for pre-dispersion and main mass transfer. This optimizes the vapor flow path and liquid flow field, and increases the gas-liquid contact area and exchange time.
It significantly improves the adequacy of gas-liquid mixing and heat exchange efficiency, enhances the separation performance of yellow phosphorus, increases purity, reduces energy consumption, and solves the problem of low efficiency in traditional trays.
Smart Images
Figure CN224220766U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of yellow phosphorus refining technology, and in particular to a multi-stage distillation column for yellow phosphorus refining. Background Technology
[0002] In existing technologies for multi-stage distillation columns used in the refining of yellow phosphorus, insufficient gas-liquid contact area and heat exchange area of the trays are the core issues restricting separation efficiency. Traditional trays, such as valve trays and sieve trays, generally have low opening ratios, resulting in limited contact area between vapor and liquid, which hinders the full realization of mass transfer. For example, the valve spacing and orifice design of valve trays are often not optimized for the high viscosity characteristics of yellow phosphorus, easily leading to uneven local gas velocity during vapor rise. This prevents impurities in the liquid phase, such as arsenides and sulfides, from effectively transferring to the gas phase, ultimately affecting the removal effect. In addition, unreasonable weir height and downcomer structure design result in insufficient or uneven liquid holdup on the trays, further reducing gas-liquid contact time. For example, one company increased the weir height of a valve tray from 25mm to 40mm, which increased the liquid holdup, but the tower pressure difference decreased from 10kPa. The sudden increase to 20 kPa doubled energy consumption without a significant improvement in separation efficiency, exposing the limitations of traditional trays in balancing mass transfer and pressure drop.
[0003] The problem of insufficient heat exchange area is also prominent. Yellow phosphorus refining requires high temperatures, typically 200-300°C, but the existing tray structure design fails to fully utilize the internal space of the column to enhance heat transfer. For example, the floating valves in the valve tray only provide a limited number of gas-liquid contact points, and the liquid flow path on the tray is short and singular, resulting in low heat exchange efficiency. This defect is particularly evident when processing yellow phosphorus containing high-boiling-point impurities such as metal salts: the counter-current contact between high-temperature steam and liquid is insufficient, light components cannot be fully vaporized, and heavy components are difficult to condense, ultimately resulting in insufficient purity of yellow phosphorus at the top of the column and high residual impurities at the bottom. In addition, traditional trays lack an efficient heat recovery mechanism, and more than 30% of the energy consumption during the distillation process is wasted, exacerbating production cost pressures.
[0004] To address the aforementioned issues, some attempts at improvement, such as replacing trays with structured packing, have been made to enhance mass transfer efficiency. However, due to the ease with which yellow phosphorus solidifies and its strong corrosiveness, the packing is prone to clogging and difficult to maintain, making it difficult to widely apply in industry. Therefore, the insufficient gas-liquid contact interface and heat exchange area of trays in existing technologies have become a key bottleneck restricting the development of yellow phosphorus refining towards high purity and low energy consumption. Utility Model Content
[0005] The purpose of this invention is to provide a multi-stage distillation column for the refining of yellow phosphorus, which can solve the problems mentioned in the background art.
[0006] To achieve the above objectives, this utility model provides the following technical solution: a multi-stage distillation column for yellow phosphorus refining, comprising a lower column body, a mounting skirt, a middle column body, an upper column body, an upper cover, and a lower cover. The mounting skirt is connected to the bottom end face of the lower column body, the middle column body is connected to the top end face of the lower column body, the lower cover is connected to the inner side of the connection between the lower column body and the mounting skirt and seals both, the upper column body is connected to the top end face of the middle column body and communicates with its interior, the upper cover is connected to the top end face of the upper column body and seals it, and an outlet pipe communicating with its interior is connected to the center of the top of the upper cover.
[0007] It also includes reboiler tubes, tray modules, and liquid outlet pipes. Multiple sets of relatively arranged and staggered liquid outlet pipes are integrally connected to the outer wall of the upper column. Multiple sets of tray modules corresponding to the number of liquid outlet pipes are installed inside the upper column. The bottom of the lower cover is detachably connected to a reboiler tube that communicates with its interior. The reboiler tube extends through the outer wall of the lower column to the outside of the lower column.
[0008] Preferably, the tray module includes a tray base, connecting holes, a distribution cap, and a flow guide plate. Multiple tray bases are embedded in the inner wall of the upper tower body. The tray base has a double-layer ladder structure. Multiple arrayed connecting holes are integrally formed on the surface of the tray base. A distribution cap is detachably installed on the surface of the tray base directly above the connecting holes. A flow guide plate is integrally connected to the side of the tray base. The bottom end face of the flow guide plate is provided with a bend. The angle between the tray base and the flow guide plate is a right angle. The axis of the liquid outlet pipe is perpendicular to the surface of the flow guide plate.
[0009] Preferably, the distributed cap includes a cap body, notches, and heat exchange holes. The cap body is a hollow structure with an open bottom. Multiple notches of varying thickness are arranged in a ring-shaped array on the outer wall of the cap body near its bottom opening. The outer wall of the cap body is provided with densely distributed heat exchange holes.
[0010] Preferably, the middle section of the outer wall of the middle tower is integrally connected to a feed pipe and a preheating pipe that communicate with its interior. A manhole A that communicates with its interior is connected to a position on the outer wall of the middle tower that is coaxial with and opposite to the preheating pipe. Multiple sets of manholes B that are distributed along the axial direction are connected to the outer wall of the upper tower.
[0011] Preferably, the surface of the upper cover is integrally formed with an inlet pipe and an outlet pipe, the upper cover is a double-layer hollow structure, the hollow structure inside the upper cover forms a heat exchange chamber, and the inlet pipe and the outlet pipe are both connected to the heat exchange chamber inside the upper cover.
[0012] Compared with the prior art, the beneficial effects of this utility model are:
[0013] In a multi-stage distillation column for yellow phosphorus refining, a distribution cap with a lower, suspended structure and densely perforated surface effectively addresses the problem of insufficient gas-liquid contact interface and heat exchange area in traditional trays through its unique structural design. The lower part of the distribution cap forms an independent steam channel, allowing rising steam to be pre-dispersed in the suspended space before uniformly entering the liquid layer of the tray through the densely perforated surface. This expands the single contact interface into a double-layer contact structure of "pre-dispersion + main mass transfer." This design increases the number of contact points between steam and liquid, resulting in more thorough gas-liquid mixing, a significantly larger contact area, and promotes the mass transfer process of impurities in the gas and liquid phases. At the same time, the suspended structure optimizes the steam flow path, avoiding mass transfer dead zones caused by uneven local gas velocity, allowing for more efficient heat exchange in the gas-liquid counter-current contact, and enhancing the separation effect of light and heavy components. Structurally, this provides a fundamental guarantee for the refining of high-purity yellow phosphorus.
[0014] The angled guide plate at the bottom addresses the problem of uneven liquid flow caused by the lack of flow guiding components in traditional trays, improving separation efficiency through flow field optimization. The angled design of the guide plate changes the flow direction of the liquid after it flows out of the downcomer, guiding it to spread evenly on the tray, effectively avoiding the flow deviation phenomenon of fast flow velocity at the edge and slow flow velocity in the center, and significantly increasing the liquid coverage area. The flow guiding effect of the angle extends the flow path of the liquid on the tray, increasing the gas-liquid cross-flow contact time, allowing for more complete mass and heat exchange between vapor and liquid. This structural design suppresses liquid short-circuiting and local stagnation, reduces mass transfer blind zones, and creates conditions for stable contact between the gas and liquid phases on the tray by rationally guiding fluid flow. Combined with the mass transfer enhancement effect of the distribution cap, it jointly improves the separation performance of the distillation column and solves the problem of low efficiency caused by the lack of flow guiding components in traditional trays. Attached Figure Description
[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0016] Figure 1 This is a perspective view of the present utility model;
[0017] Figure 2 This is a cross-sectional view of the present invention;
[0018] Figure 3 This is an enlarged view of part A of this utility model;
[0019] Figure 4 This is a structural diagram of the distributed cap component in this utility model.
[0020] Reference numerals: 1. Lower tower body; 2. Mounting skirt; 3. Middle tower body; 4. Upper tower body; 5. Upper cap; 6. Lower cap; 7. Reboiler tube; 8. Manhole A; 9. Tray module; 91. Tray base; 92. Connecting hole; 93. Distribution cap; 931. Cap body; 932. Notch; 933. Heat exchange hole; 94. Flow guide plate; 10. Liquid outlet pipe; 11. Feed pipe; 12. Preheating pipe; 13. Gas outlet pipe; 14. Water inlet pipe; 15. Water outlet pipe; 16. Manhole B. Detailed Implementation
[0021] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0022] Please see Figure 1-4 This utility model provides a technical solution: a multi-stage distillation column for yellow phosphorus refining, comprising a lower column body 1, a mounting skirt 2, a middle column body 3, an upper column body 4, an upper cover 5, and a lower cover 6. The mounting skirt 2 is connected to the bottom end face of the lower column body 1, the middle column body 3 is connected to the top end face of the lower column body 1, the lower cover 6 is connected to the inner side of the connection between the lower column body 1 and the mounting skirt 2 and seals them, the upper column body 4 is connected to the top end face of the middle column body 3 and communicates with its interior, and the upper cover 5 is connected to the top end face of the upper column body 4 and... The upper cover 5 is sealed, and the top center of the upper cover 5 is connected to the gas outlet pipe 13 that communicates with its interior. It also includes a reboiler tube 7, a tray module 9 and a liquid outlet pipe 10. Multiple sets of oppositely arranged and staggered liquid outlet pipes 10 are integrally connected to the outer wall of the upper tower body 4. Multiple sets of tray modules 9 corresponding to the number of liquid outlet pipes 10 are installed inside the upper tower body 4. The bottom of the lower cover 6 is detachably connected to the reboiler tube 7 that communicates with its interior. The reboiler tube 7 extends through the outer wall of the lower tower body 1 to the outside of the lower tower body 1.
[0023] The tray module 9 includes a tray base 91, connecting holes 92, distribution caps 93, and guide plates 94. Multiple tray bases 91 are embedded in the inner wall of the upper tower body 4. Each tray base 91 has a double-tiered structure. Multiple arrayed connecting holes 92 are integrally formed on the surface of the tray base 91. Distribution caps 93 are detachably installed on the surface of the tray base 91 directly above the connecting holes 92. The detachable distribution caps 93 facilitate cleaning, maintenance, and replacement. Guide plates 94 are integrally connected to the side of the tray base 91. The bottom end face of the guide plate 94 has a bend, which changes the flow direction of the liquid after it flows out of the downcomer, guiding it to spread evenly on the tray. This effectively avoids the flow deviation phenomenon where the flow velocity is fast at the edge and slow at the center, significantly increasing the liquid coverage area; the guiding effect formed by the bend extends the flow path of the liquid on the tray, increases the gas-liquid cross-flow contact time, and allows the steam and liquid to exchange mass and heat more fully; the angle between the tray base 91 and the guide plate 94 is a right angle, and the axis of the liquid outlet pipe 10 is perpendicular to the surface of the guide plate 94; the distribution cap 93 includes a cap body 931, a notch 932 and heat exchange holes 933. The cap body 931 is a hollow structure with an open bottom. The outer wall of the cap body 931 has multiple notches 932 arranged in a ring array near its bottom opening. The outer wall of the cap body 931 has densely distributed heat exchange holes 933.
[0024] The distribution cap, with its elevated lower section and densely perforated surface, effectively addresses the shortcomings of insufficient gas-liquid contact interface and heat exchange area in traditional trays through its unique structural design. The elevated lower section of the distribution cap creates an independent vapor channel, allowing rising vapor to be pre-dispersed in the elevated space before uniformly entering the liquid layer of the tray through the densely perforated surface. This expands the single contact interface into a "pre-dispersion + main mass transfer" model. The upper tower 3 has a double-layer contact structure; the middle section of the outer wall of the middle tower body 3 is integrally connected to the feed pipe 11 and the preheating pipe 12, which communicate with the interior. The outer wall of the middle tower body 3 is connected to the preheating pipe 12 at a position coaxial with it, and the upper tower body 4 is connected to multiple sets of manholes B16 distributed along its axial direction. The distribution cap 93 can be removed from the manhole B16. The surface of the upper cover 5 is integrally connected to the water inlet pipe 14 and the water outlet pipe 15. The upper cover 5 has a double-layer hollow structure. The hollow structure inside the upper cover 5 forms a heat exchange chamber. The water inlet pipe 14 and the water outlet pipe 15 are both connected to the heat exchange chamber inside the upper cover 5.
[0025] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.
Claims
1. A multi-stage distillation column for the refining of yellow phosphorus, characterized in that, include: The lower tower body (1), mounting skirt (2), middle tower body (3), upper tower body (4), upper cover (5) and lower cover (6) are connected to the bottom end face of the lower tower body (1), the middle tower body (3) is connected to the top end face of the lower tower body (1), the lower cover (6) is connected to the inside of the connection between the lower tower body (1) and the mounting skirt (2) and seals them together, the upper tower body (4) is connected to the top end face of the middle tower body (3) and communicates with its interior, the upper cover (5) is connected to the top end face of the upper tower body (4) and seals it, and the top center of the upper cover (5) is connected to an exhaust pipe (13) that communicates with its interior. The upper column body (4) has multiple sets of oppositely arranged and staggered outlet pipes (10) integrally formed on the outer wall of the upper column body (4). The upper column body (4) has multiple sets of tray modules (9) corresponding to the number of outlet pipes (10) installed inside. The bottom of the lower cover (6) is detachably connected to the reboiler tube (7) communicating with its interior. The reboiler tube (7) extends through the outer wall of the lower column body (1) to the outside of the lower column body (1).
2. The multi-stage distillation column for yellow phosphorus refining according to claim 1, characterized in that: The tray module (9) includes a tray base (91), a connecting hole (92), a distribution cap (93), and a flow guide plate (94). Multiple tray bases (91) are embedded in the inner wall of the upper tower body (4). The tray base (91) has a double-layer ladder structure. Multiple arrayed connecting holes (92) are integrally formed on the surface of the tray base (91). A distribution cap (93) is detachably installed on the surface of the tray base (91) at a position directly above the connecting hole (92). A flow guide plate (94) is integrally connected to the side of the tray base (91). A bend is provided on the bottom end face of the flow guide plate (94). The angle between the tray base (91) and the flow guide plate (94) is a right angle. The axis of the liquid outlet pipe (10) is perpendicular to the surface of the flow guide plate (94).
3. A multi-stage distillation column for refining yellow phosphorus according to claim 2, characterized in that: The distributed cap (93) includes a cap body (931), a notch (932) and heat exchange holes (933). The cap body (931) is a hollow structure with an opening at the bottom. The outer wall of the cap body (931) has a notch (932) with multiple coarse diameters arranged in a ring array near the opening at the bottom. The outer wall of the cap body (931) has densely distributed heat exchange holes (933).
4. A multi-stage distillation column for refining yellow phosphorus according to claim 3, characterized in that: The middle section of the outer wall of the middle tower body (3) is integrally formed with a feed pipe (11) and a preheating pipe (12) that communicate with its interior. The outer wall of the middle tower body (3) is connected to a manhole A (8) that communicates with its interior at a position coaxially opposite to the preheating pipe (12). The outer wall of the upper tower body (4) is connected to multiple sets of manholes B (16) distributed along its axial direction.
5. A multi-stage distillation column for refining yellow phosphorus according to claim 4, characterized in that: The surface of the upper cover (5) is integrally connected with an inlet pipe (14) and an outlet pipe (15). The upper cover (5) is a double-layer hollow structure. The hollow structure inside the upper cover (5) forms a heat exchange chamber. The inlet pipe (14) and the outlet pipe (15) are both connected to the heat exchange chamber inside the upper cover (5).