C4 extractive distillation tower
Through the design of the drop-down multi-liquid injection tower, the problems of the traditional tower tray in the carbon four-extraction distillation tower are solved, such as small processing volume, large pressure drop, and easy blockage, and the efficient gas-liquid mass transfer and separation effect are achieved.
Patent Information
- Application Number
- CN202422218402.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-11
AI Technical Summary
Among the existing carbon four-extraction distillation towers, traditional tower trays have problems such as small processing volume, severe pressure drop, easy blockage, and poor impact resistance, resulting in poor use effect.
The structure design of the drop-down multi-liquid jet tower tray is adopted, including the tower tray plate, the liquid drop-down tank, the liquid receiving tank, the cover body, the support plate, the top plate, the plate hole and the liquid conduction tank is optimized, combined with the upper and lower filler sections, the gas-liquid contact and mass transfer process are optimized.
It improves the gas-liquid contact efficiency, increases the processing capacity, reduces the pressure drop, extends the life of the tower, prevents blockage, and improves the mass transfer efficiency and separation effect.
Smart Images
Figure CN223042182U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an extractive distillation column in the chemical industry field, specifically a C4 extractive distillation column. Background Art
[0002] At present, the C4 extractive distillation column is mainly used for the separation and distillation process of mixed C4 generated in the petrochemical refining process. Due to different manufacturing methods, the raw material C4 can be divided into mixed C4 and refinery C4. Mixed C4 is an important petrochemical resource, and refinery C4 is mainly used to make fuel. In recent years, with the improvement of the crude oil processing depth in refineries and the substantial increase in ethylene production capacity, and the completion of million-ton steam pyrolysis ethylene plants, the by-product C4 volume has increased rapidly. Coupled with the rise of new coal-based chemical processes and new technologies for producing light olefins mainly composed of ethylene and propylene by catalytic reaction of methanol, the production of C4 is even more astonishing. Therefore, the utilization of C4 is very important.
[0003] As a separation and distillation device for C4 rectification, the C4 extractive distillation column mainly consists of a tower body and internal components. Currently, the widely used internal components in the C4 extractive distillation column include packing and its distributors, trays and their accessories. The traditional bubbling trays are mainly floating valve trays, and their disadvantages are small processing capacity, serious pressure drop, easy blockage, and easy damage of floating valves, resulting in poor use effects of the bubbling trays. The spraying trays take the vertical sieve tray as an example, and its disadvantages are serious gas-liquid entrainment, easy blockage structure in the cap, and poor impact resistance of the vertical sieve tray, and its effect is not good in actual production. Summary of the Utility Model
[0004] Aiming at the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a C4 extractive distillation column.
[0005] The technical solution for the utility model to solve the above technical problem is to provide a C4 extractive distillation column, which is characterized in that the distillation column includes a tower body, a tray section, an upper packing section, a lower packing section, a gas outlet, a solvent inlet, a C4 inlet, a gas inlet and a liquid outlet;
[0006] The upper packing section is fixed on the inner wall of the tower body and is located in the upper part of the tower body; the lower packing section is fixed on the inner wall of the tower body and is located in the lower part of the tower body; the tray section is fixed on the inner wall of the tower body and is located in the middle of the tower body and between the upper packing section and the lower packing section; the tower body is provided with a gas outlet, a solvent inlet, a C4 inlet, a gas inlet and a liquid outlet;
[0007] The tray section is composed of a number of trays in layers; each tray includes a tray plate, a downcomer, a receiving trough, a cover body, a support plate, a top plate, plate holes, a liquid guiding groove and a spraying hole;
[0008] The tray plates are fixed on the inner wall of the tower body; downcomer troughs and liquid receiving troughs are respectively formed at the central positions of the tray plates of two adjacent layers; on the tray plate with a downcomer trough formed at the central position, a plurality of downcomer troughs are symmetrically formed on both sides of the downcomer trough at the central position, and liquid receiving troughs are formed between two adjacent downcomer troughs; on the tray plate with a liquid receiving trough formed at the central position, a plurality of liquid receiving troughs are symmetrically formed on both sides of the liquid receiving trough at the central position, and downcomer troughs are formed between two adjacent liquid receiving troughs; each downcomer trough corresponds to its respective liquid receiving trough; a plurality of spray holes are formed at the bottom of the downcomer trough;
[0009] A plurality of plate holes are formed on the tray plate, and the plate holes are located between adjacent downcomer troughs and liquid receiving troughs; a cover body is arranged at each plate hole; a plurality of cover bodies are fixed on the tray plate through legs, and there is a gap between the bottom end of the cover body and the tray plate; a top plate is fixed on the top of each cover body through a support plate, and there is a gap between the top plate and the top end of the cover body; a liquid guiding trough is fixed on the middle part of the outer side walls of all the cover bodies located in the same column; one end of the liquid guiding trough is open, and the opening is communicated with the downcomer trough.
[0010] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0011] (1) The present utility model adopts a showering multi-downcomer jet tray. The cover body structure of the tray can make the gas-liquid contract and jet, and the gas-liquid contact is more sufficient, ensuring the uniformity and dispersion of the jet; the orifice ratio of the tray is larger, and the lifting amount of the liquid increases significantly, with strong processing capacity; the distance between the top plate and the cover body is larger. After the gas-liquid impacts the top plate, it will scatter outwards from the upper gap, and the force on the top plate and the cover body will be reduced, avoiding being lifted by the gas. This not only increases the gas-liquid mass transfer space, making the mass transfer more sufficient, but also extends the service life of the tray; the plate holes on the tray are larger and there are no moving parts, and the upper gap between the top plate and the cover body is larger, so it is generally not easily blocked by dirty or viscous materials; in the mass transfer area of the tray, the gas does not need to pass through the liquid layer on the tray plate, and only needs to overcome the gravity of the part of the liquid lifted by the gas, so the pressure drop caused is smaller.
[0012] (2) The present utility model adopts a showering multi-downcomer trough. A plurality of spray holes are formed at the bottom of the downcomer trough, which can not only play the role of holding liquid and reducing foam, but also increase the residence time of the liquid in the downcomer pipe, effectively eliminating the bubbles on the upper tray and preventing them from entering the lower tray to cause gas phase backmixing, increasing the operating flexibility of the downcomer trough, and thus ensuring the high mass transfer efficiency of each tray.
[0013] (3) The present utility model adopts a showering multi-downcomer trough, and the downcomer trough can be used as a support beam, and each component can be disassembled and assembled through a manhole. The tray plate adopts a bending structure and there is no main beam directly welded to the tower body. The structure is simple, scientific and reasonable, which not only reduces the material use but also facilitates installation and maintenance.
[0014] (4) The tray of the present utility model is provided with a liquid guiding groove structure. The setting of the liquid guiding groove isolates the liquid that has undergone mass transfer and the liquid that has not undergone mass transfer, enabling the liquid undergoing gas-liquid mass transfer to directly flow from the liquid guiding groove through the downcomer to the next tray, avoiding backmixing with the liquid on the tray that has not undergone gas-liquid contact, forming the largest difference between the liquid component concentration and the gas component concentration, thereby greatly improving the mass transfer driving force and tray efficiency.
[0015] (5) The present utility model is provided with a packing section of a certain height above the interior of the tower. The height of this packing section is generally about 3000 mm. It can capture the small solvent droplets entrained by the gas phase during the gas-liquid mass transfer process, eliminating liquid-phase backmixing, avoiding entrainment of mists and foams, and at the same time playing a role in recovering the solvent, increasing the gas-liquid contact area, and further improving the mass transfer and separation efficiency.
[0016] (6) The present utility model is provided with a packing section of a certain height below the interior of the tower. The height of this packing section is generally about 600 mm. The liquid-phase foam generated during the gas-liquid mass transfer process is broken when passing through this packing section, avoiding liquid-phase backmixing to a certain extent, and at the same time playing a role in maintaining the stability of the tower bottom liquid level. Brief Description of the Drawings
[0017] Figure 1 is a schematic diagram of the overall structure of the present utility model;
[0018] Figure 2 is a front view schematic diagram of the tray of the present utility model;
[0019] Figure 3 is a top view schematic diagram of the tray of the present utility model.
[0020] In the figure, the tower body 1, the tray section 2, the upper packing section 3, the lower packing section 4, the gas outlet 5, the solvent inlet 6, the C4 inlet 7, the gas inlet 8, the liquid outlet 9;
[0021] The tray plate 21, the downcomer 22, the liquid receiving tank 23, the cover body 24, the support plate 25, the top plate 26, the plate hole 27, the liquid guiding groove 28, the spray hole 29. Detailed Description of the Preferred Embodiments
[0022] The following are specific embodiments of the present utility model. The specific embodiments are only used to further illustrate the present utility model in detail and do not limit the protection scope of the present utility model.
[0023] The present utility model provides a C4 extractive distillation tower (referred to as a distillation tower), which is characterized in that the distillation tower includes a tower body 1, a tray section 2, an upper packing section 3, a lower packing section 4, a gas outlet 5, a solvent inlet 6, a C4 inlet 7, a gas inlet 8, and a liquid outlet 9;
[0024] The upper packing section 3 is fixed to the inner wall of the tower body 1 and is located in the upper part inside the tower body 1; the lower packing section 4 is fixed to the inner wall of the tower body 1 and is located in the lower part inside the tower body 1; the tray section 2 is fixed to the inner wall of the tower body 1 and is located in the middle part inside the tower body 1 and between the upper packing section 3 and the lower packing section 4; a gas outlet 5, a solvent inlet 6, a C4 inlet 7, a gas inlet 8 and a liquid outlet 9 are provided on the tower body 1;
[0025] The tray section 2 is composed of a number of trays in layers; each tray includes a tray plate 21, a downcomer 22, a liquid receiving trough 23, a hood 24, a support plate 25, a top plate 26, plate holes 27, a liquid guiding trough 28 and spray holes 29;
[0026] The tray plate 21 is fixed to the inner wall of the tower body 1; a downcomer 22 and a liquid receiving trough 23 are respectively opened at the central positions of the tray plates 21 of adjacent two layers of trays; on the tray plate 21 with a downcomer 22 opened at the central position, a number of downcomers 22 are symmetrically opened on both sides of the downcomer 22 at the central position, and a liquid receiving trough 23 is opened between adjacent two downcomers 22; on the tray plate 21 with a liquid receiving trough 23 opened at the central position, a number of liquid receiving troughs 23 are symmetrically opened on both sides of the liquid receiving trough 23 at the central position, and a downcomer 22 is opened between adjacent two liquid receiving troughs 23; each downcomer 22 corresponds to its respective liquid receiving trough 23; a number of spray holes 29 are opened at the bottom of the downcomer 22;
[0027] A number of plate holes 27 are opened on the tray plate 21, and the plate holes 27 are located between adjacent downcomers 22 and liquid receiving troughs 23; a hood 24 is provided at each plate hole 27, and the position of the hood 24 corresponds to its respective plate hole 27; a number of hoods 24 are fixed on the tray plate 21 through legs, and there is a gap (i.e., bottom gap) between the bottom end of the hood 24 and the tray plate 21; a top plate 26 is fixed to the top of each hood 24 through a support plate 25, and there is a gap (i.e., upper gap) between the top end of the top plate 26 and the hood 24; a liquid guiding trough 28 is fixed to the middle part of the outer side walls of all the hoods 24 in the same column; one end of the liquid guiding trough 28 is open, and the opening is communicated with the downcomer 22.
[0028] Preferably, the gas outlet 5 is provided at the top of the tower body 1; the solvent inlet 6 is provided at the upper part of the side wall of the tower body 1 and above the tray section 2; the C4 inlet 7 is provided at the middle part of the side wall of the tower body 1 and in the middle of the tray section 2; the gas inlet 8 is provided at the lower part of the side wall of the tower body 1 and below the tray section 2; the liquid outlet 9 is provided at the bottom of the tower body 1.
[0029] Preferably, the upper packing section 3 uses demisting packing, and the lower packing section 4 uses anti-foam packing.
[0030] Preferably, the cover body 24, the top plate 26 and the plate hole 27 are coaxial. The diameter of the bottom surface circle of the cover body 24 is greater than the diameter of the plate hole 27, and the diameter of the top plate 26 is greater than the diameter of the top surface circle of the cover body 24.
[0031] Preferably, the cover body 24, the top plate 26 and the plate hole 27 are the same in number.
[0032] Preferably, the cover body 24 is of a hollow cylindrical or hollow frustum-shaped (preferably hollow frustum-shaped) structure, the plate hole 27 is a circular hole, and the top plate 26 is a circular plate.
[0033] Preferably, at least two support plates 25 are evenly fixed on the circumference of each cover body 24.
[0034] Preferably, each top plate 26 is located directly above its respective cover body 24.
[0035] Preferably, the length of the downcomer 22 depends on the diameter or chord length of its location; the length of the downcomer 22 at the central position is the same as the diameter of the tray plate 21, and the length of the downcomer 22 at other positions depends on the chord length of the position where the downcomer 22 is located.
[0036] Preferably, the length of the liquid receiving trough 23 depends on the diameter or chord length of its location; the length of the liquid receiving trough 23 at the central position is the same as the diameter of the tray plate 21, and the length of the liquid receiving trough 23 at other positions depends on the chord length of the position where the liquid receiving trough 23 is located.
[0037] Preferably, the depth of the downcomer 22 is 200 - 500 mm (preferably 300 mm), and the width is 50 - 400 mm.
[0038] Preferably, the width occupied by the cover body 24 on the tray plate 21 is the same as the width of the liquid guiding trough 28.
[0039] Preferably, the shape of the spray hole 29 is circular, and the number of spray holes 29 is adjusted to ensure that the effective liquid level height of the downcomer 22 is maintained at 50 - 60 mm.
[0040] The working principle and working process of the present utility model are as follows:
[0041] C4 (carbon four) enters the tower body 1 from the C4 inlet 7, and the solvent enters the tower body 1 from the solvent inlet 6. The liquid entering the tower body 1 enters the hood 24 through the bottom gap between the hood 24 and the tray plate 21, is lifted, formed into a film, and broken under the action of the gas, and contacts and mass transfers inside the tower body 1. The liquid is dispersed into small droplets and rises to the lower surface of the upper packing section 3. The droplets are trapped by the upper packing section 3 and converge into large droplets, which fall onto the tray plate 21, flow through several layers of trays from top to bottom, reach the bottom of the tower body 1, continue to pass through the lower packing section 4 downward, and are discharged through the liquid outlet 9; The gas enters the tower body 1 from the gas inlet 8, passes through several layers of trays from bottom to top, continues to pass through the upper packing section 3 upward, contacts and mass transfers with the liquid wetting the upper packing section 3, and is discharged through the gas outlet 5;
[0042] The working principle and working process of the tray plate 21 are as follows:
[0043] The liquid flows from the downcomer 22 of the upper layer tray through the spray holes 29 to the liquid receiving tank 23 of this layer tray, then flows through the tray plate 21 of this layer from the liquid receiving tank 23, and then flows to the downcomer 22 of the next layer tray; when the liquid flows through the tray plate 21 of this layer, the liquid enters the hood 24 through the gap (i.e., the bottom gap) between the hood 24 and the tray plate 21; the gas rising from below the tray plate 21 of this layer contracts and accelerates through the plate holes 27 of the tray plate 21 of this layer and enters the hood 24. The gas lifts the liquid entering the hood 24 into an annular film, impacts on the top plate 26, and the liquid scatters outward in a circular shape from the gap (i.e., the upper gap) between the hood 24 and the top plate 26 into a large number of small droplets. The ejected small droplets fall into the liquid guiding groove 28. The liquid guiding groove 28 isolates the liquid that has undergone mass transfer and the liquid that has not undergone mass transfer, enabling the liquid that has undergone gas-liquid mass transfer to directly flow from the liquid guiding groove 28 through the downcomer 22 to the next layer tray, avoiding backmixing with the liquid that has not undergone gas-liquid contact on the tray plate 21 of this layer, forming the largest difference between the liquid component concentration and the gas component concentration, thereby greatly improving the mass transfer driving force and tray efficiency.
[0044] Those not described in this utility model are applicable to the prior art.
Claims
1. A C4 extractive distillation tower, characterized in that: The distillation tower comprises a tower body (1), a tray section (2), an upper packing section (3), a lower packing section (4), a gas outlet (5), a solvent inlet (6), a C4 inlet (7), a gas inlet (8) and a liquid outlet (9); The upper filling section (3) is fixed on the inner wall of the tower body (1) and is located at the upper part of the tower body (1); The lower packing section (4) is fixed on the inner wall of the tower body (1) and is located in the lower part of the tower body (1); the tray section (2) is fixed on the inner wall of the tower body (1) and is located in the middle part of the tower body (1) and between the upper packing section (3) and the lower packing section (4); the tower body (1) is provided with a gas outlet (5), a solvent inlet (6), a C4 inlet (7), a gas inlet (8) and a liquid outlet (9); The tray section (2) is composed of a plurality of trays in a layered form; each tray comprises a tray plate (21), a liquid downcomer (22), a liquid receiving trough (23), a cover body (24), a support plate (25), a top plate (26), a plate hole (27), a liquid guide groove (28) and a spray hole (29); The tower plate (21) is fixed on the inner wall of the tower body (1); a liquid downcomer (22) and a liquid receiving trough (23) are respectively provided at the center of the tower plate (21) of two adjacent tower plates; on the tower plate (21) with the liquid downcomer (22) at the center, a plurality of liquid downcomers (22) are symmetrically provided on both sides of the liquid downcomer (22) at the center, and a liquid receiving trough (23) is provided between two adjacent liquid downcomers (22); on the tower plate (21) with the liquid receiving trough (23) at the center, a plurality of liquid receiving troughs (23) are symmetrically provided on both sides of the liquid receiving trough (23) at the center, and a liquid downcomer (22) is provided between two adjacent liquid receiving troughs (23); each liquid downcomer (22) corresponds to its own liquid receiving trough (23); and a plurality of spray holes (29) are provided at the bottom of the liquid downcomer (22); A plurality of plate holes (27) are formed on a tray plate (21), and the plate holes (27) are located between adjacent downcomers (22) and receiving troughs (23); a cover body (24) is provided at each plate hole (27); the plurality of cover bodies (24) are fixed on the tray plate (21) through legs, and a gap is provided between the bottom end of the cover body (24) and the tray plate (21); a top plate (26) is fixed on the top of each cover body (24) through a support plate (25), and a gap is provided between the top plate (26) and the top end of the cover body (24); a liquid guide groove (28) is fixed on the middle part of the outer side wall of all the cover bodies (24) located in the same row; one end of the liquid guide groove (28) is open, and the opening is communicated with the downcomer (22).
2. The C4 extractive distillation tower according to claim 1, characterized in that: The gas outlet (5) is arranged at the top of the tower body (1); the solvent inlet (6) is arranged at the upper part of the side wall of the tower body (1), and is located above the tower tray section (2); the C4 inlet (7) is arranged at the middle part of the side wall of the tower body (1), and is located in the middle part of the tower tray section (2); the gas inlet (8) is arranged at the lower part of the side wall of the tower body (1), and is located below the tower tray section (2); and the liquid outlet (9) is arranged at the bottom of the tower body (1).
3. The C4 extractive distillation tower according to claim 1, characterized in that: The cover body (24), the top plate (26) and the plate hole (27) are coaxial, the diameter of the bottom circle of the cover body (24) is larger than the diameter of the plate hole (27), and the diameter of the top plate (26) is larger than the diameter of the top circle of the cover body (24).
4. The C4 extractive distillation tower according to claim 1, characterized in that: The cover body (24) is a hollow cylindrical or hollow truncated cone structure, the plate hole (27) is a circular hole, and the top plate (26) is a circular plate.
5. The C4 extractive distillation tower according to claim 1, characterized in that: At least two support plates (25) are evenly distributed and fixed on the circumference of each cover body (24).
6. The C4 extractive distillation tower according to claim 1, characterized in that: Each top plate (26) is located directly above the respective cover body (24).
7. The C4 extractive distillation tower according to claim 1, characterized in that: The downcomer (22) has a depth of 200 to 500 mm and a width of 50 to 400 mm.
8. The C4 extractive distillation tower according to claim 1, characterized in that: The spray holes (29) are circular in shape, and the effective liquid level height of the downcomer (22) is ensured to be 50-60 mm by adjusting the number of the spray holes (29).
9. The C4 extractive distillation tower according to claim 1, characterized in that: The upper packing section (3) adopts defoaming packing, and the lower packing section (4) adopts anti-foaming packing.