CN113262517A

CN113262517A - Inner tube rectifying tower for separating mixed fraction of C12-C15 normal paraffins

Info

Publication number: CN113262517A
Application number: CN202110537687.2A
Authority: CN
Inventors: 黄睿翔; 张一星; 张永伟; 胡波; 郭志重
Original assignee: Henan Zt League Chemical Co ltd
Current assignee: Henan Zt League Chemical Co ltd
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2021-08-17

Abstract

A rectifying tower with an inner barrel for separating mixed fraction of C12-C15 n-alkane relates to a sleeve rectifying tower structure, wherein a vertically arranged barrel (27) is arranged in the middle of a cavity, the barrel (27) divides the cavity into four parts, a plurality of tower plates (26) are arranged in an inner barrel side line extraction section (14) at intervals, a C-shaped pipe (30) is sleeved in the middle of the outer wall of a tower body (11), an annular packing layer A (10) is arranged in an outer barrel rectifying feeding section (23) above a connecting pipe (31), and an annular packing layer B (28) is arranged in an outer barrel rectifying feeding section (23) below the connecting pipe (31); according to the invention, the partition plate of the partition plate rectifying tower is replaced by the cylindrical structure, the plurality of tower plates are arranged in the inner cylinder which is arranged as the side line extraction section, and the plurality of annular packing layers are arranged in the area between the inner cylinder and the tower body, so that the packing layers can be separated more accurately during feeding, and can be extracted more quickly during side line extraction.

Description

Inner tube rectifying tower for separating mixed fraction of C12-C15 normal paraffins

Technical Field

The invention relates to a sleeve rectifying tower structure, in particular to an inner sleeve rectifying tower for separating mixed fraction of C12-C15 normal paraffins.

Background

The mixed fraction contained in the Fischer-Tropsch synthetic oil mostly comprises normal paraffins of C8-C20. In industrial production, distillation cut fraction or multiple times of vacuum distillation are mainly adopted to extract normal alkane in Fischer-Tropsch synthetic oil, when the separation fraction is a mixture of C12-C15 normal alkane, a plurality of conventional rectifying towers are required to be connected in series to prepare high-purity normal alkane products, high equipment investment cost is required, occupied area is large, energy consumption is high due to low thermal efficiency, and a clapboard rectifying tower is commonly used for separation at present. The design of a divided rectifying column is an important thermal coupling for rectification, which has been proposed as early as the sixties of the last century. Although the concept of a baffled rectifier has been proposed for over half a century to date, there are still few baffled rectifiers that are currently in a true maturity to be used in industrial practice. Research shows that when the partition plate rectifying tower is used for separating a three-component mixture, the separation efficiency is improved and the thermodynamic efficiency is greatly improved because no back mixing phenomenon occurs in the separation process of each component. Therefore, compared with the conventional rectification process, the energy can be saved by more than 30%. In addition, the partition rectifying column is lower than the conventional rectifying column in terms of manufacturing cost. When the separation section is a mixture of C12-C15 normal paraffins, the traditional clapboard rectifying tower tray is generally designed as a filler, although the separation effect is good, the separation speed is slow, in order to finely and rapidly separate the mixed products, the separation is quicker and more thorough, and a rectifying tower with an inner cylinder is specially developed.

Disclosure of Invention

In order to overcome the defects in the background art, the invention discloses a rectifying tower with an inner barrel for separating mixed fraction of C12-C15 normal paraffin, wherein a partition plate of the rectifying tower with the partition plate is replaced by a barrel-shaped structure, a plurality of tower plates are arranged in the inner barrel which is arranged as a side line extraction section, and a plurality of annular packing layers are arranged in the area between the inner barrel and the tower body, so that the packing layers can be separated more accurately during feeding and can be extracted more quickly during side line extraction.

In order to realize the purpose, the invention adopts the following technical scheme:

a rectifying tower with an inner barrel for separating the mixed fraction of C12-C15 n-alkanes comprises a tower body, a cavity is arranged in the tower body, a barrel is vertically arranged in the middle of the cavity and divides the cavity into four parts, the cavity above the barrel forms a public rectifying section, the cavity below the barrel forms a public stripping section, the cavity between the barrel and the tower body forms an outer barrel rectifying feeding section, an inner barrel side line extracting section with an upper opening and a lower opening is arranged in the barrel, a plurality of tower plates are arranged in the inner barrel side line extracting section at intervals, each tower plate is provided with a notch, the notches between two adjacent tower plates are oppositely arranged, the top surface of each tower plate is provided with a spiral groove, the bottom of each spiral groove is provided with a plurality of water leakage holes at intervals, a packing layer A is arranged in the public rectifying section, a packing layer B is arranged in the public stripping section, a C-shaped pipe is sleeved on the middle part of the outer wall of the tower body, the inner barrel type rectifying tower is characterized in that a pipe cavity is arranged in the C-shaped pipe, a feeding pipe penetrating through the pipe cavity is arranged in the middle of the outer edge of the C-shaped pipe, a preheater is arranged on the feeding pipe, connecting pipes penetrating through the pipe cavity and the middle of the outer barrel rectifying feeding section are arranged between the middle of the inner edge of the C-shaped pipe and the outer wall of the tower body, the three connecting pipes are arranged around the tower body at equal intervals, an annular packing layer A is arranged in the outer barrel rectifying feeding section above the connecting pipes, an annular packing layer B is arranged in the outer barrel rectifying feeding section below the connecting pipes, and one end of an inner barrel extraction pipe penetrates through the outer barrel rectifying feeding section along the outer wall of the tower body and then penetrates through the middle lower portion of the inner barrel side line extraction section.

The rectifying tower with the inner barrel for separating the mixed fraction of the C12-C15 normal paraffin is characterized in that the top of the tower body is connected with one end of a tower top air outlet pipe, the other end of the tower top air outlet pipe is respectively connected with one end of a tower top return pipe and one end of a tower top discharge pipe, a condenser is arranged on the tower top air outlet pipe, the other end of the tower top return pipe is connected to the tower body above a packing layer A, and a disc distributor A is arranged on a public rectifying section between the tower top return pipe and the packing layer A.

The rectifying tower with the inner barrel for separating the C12-C15 normal paraffin mixed fraction is characterized in that the lower end of the tower body is connected with one end of a tower bottom liquid outlet pipe, the other end of the tower bottom liquid outlet pipe is respectively connected with one end of a tower bottom production pipe and one end of a tower bottom return pipe, a reboiler is arranged on the tower bottom return pipe, and the other end of the tower bottom return pipe is connected to the tower body below the packing layer B.

The rectifying tower with the inner barrel for separating the mixed fraction of the C12-C15 normal paraffins is provided with a baffle plate extending upwards on the edge of the tower plate at each notch.

The rectifying tower with the inner barrel for separating the mixed fraction of the C12-C15 normal paraffin is provided with a disc distributor B in a common stripping section between a packing layer B and a barrel body.

The rectifying tower with the inner barrel is used for separating the mixed fraction of the C12-C15 normal paraffin, and the annular distributor A is arranged in an outer barrel rectifying feed section between the annular packing layer A and the upper end of the barrel.

The rectifying tower with the inner barrel is used for separating the mixed fraction of the C12-C15 normal paraffin, and the annular distributor B is arranged in an outer barrel rectifying feed section between the annular packing layer B and the connecting pipe.

The rectifying tower with the inner barrel for separating the mixed fraction of the C12-C15 normal paraffins is characterized in that a plurality of connecting rods are fixedly connected between the inner barrel and the tower body.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

the invention relates to an inner barrel rectifying tower for separating C12-C15 normal paraffin mixed fraction, which is characterized in that a partition plate of the partition plate rectifying tower is replaced by a barrel-shaped structure, a plurality of tower plates are arranged in an inner barrel which is arranged as a side line extraction section, a plurality of annular filler layers are arranged in a region between the inner barrel and a tower body, the round inner barrel is more favorable for arranging the tower plates, and as a mixture of C13 and C14 is extracted from a middle side line extraction section, the extraction amount is larger, the structure of the tower plates is more suitable for large-batch extraction, a product C12 is extracted from the tower top, a product C15 is extracted from the tower bottom, and a high-purity product is required, the filler layers which are more thorough in separation are selected between the inner barrel and the tower body, so that the filler layers can be more accurately separated during feeding and the purpose of more rapid extraction can be realized during side line extraction; the method has the characteristics of good separation effect, high yield, short separation time and the like, and has good popularization value and wide market prospect.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the structure of the "C" shaped tube and tower body combination of the present invention;

FIG. 3 is a schematic structural view of a tray according to the present invention.

In the figure: 1. a gas outlet pipe at the top of the tower; 2. a condenser; 3. a common rectification section; 4. a discharge pipe at the top of the tower; 5. a top reflux pipe; 6. a disc distributor A; 7. a packing layer A; 8. a connecting rod; 9. an annular distributor A; 10. an annular packing layer A; 11. a tower body; 12. a baffle plate; 13. an inner cylinder extraction pipe; 14. an inner cylinder lateral line extraction section; 15. an annular distributor B; 16. a disc distributor B; 17. a packing layer B; 18. a common stripping section; 19. a tower bottom return pipe; 20. a reboiler; 21. a tower bottom production pipe; 22. a liquid outlet pipe at the bottom of the tower; 23. an outer barrel rectification feed section; 24. a feed pipe; 25. a preheater; 26. a column plate; 27. a barrel; 28. an annular packing layer B; 29. opening the gap; 30. a "C" shaped tube; 31. a connecting pipe; 32. a spiral groove; 33. and (4) water leakage holes.

Detailed Description

The present invention will be explained in more detail by the following examples, which are not intended to limit the present invention, and all changes and modifications within the scope of the present invention are intended to be protected by the disclosure of the present invention;

the rectification tower with an inner cylinder for separating the mixed fraction of C12-C15 normal paraffin, which is described by combining the attached drawings 1, 2 or 3, comprises a tower body 11, a cavity is arranged in the tower body 11, a cylinder 27 which is vertically arranged is arranged in the middle of the cavity, a plurality of connecting rods 8 are fixedly connected between the cylinder 27 and the tower body 11, the cylinder 27 divides the cavity into four parts, the cavity above the cylinder 27 forms a common rectification section 3, the cavity below the cylinder 27 forms a common stripping section 18, the cavity between the cylinder 27 and the tower body 11 forms an outer cylinder rectification feeding section 23, an inner cylinder side line extraction section 14 with an opening at the upper end and a lower end is arranged in the cylinder 27, a plurality of tower plates 26 are arranged in the inner cylinder side line extraction section 14 at intervals, each tower plate 26 is provided with an opening 29, the edge of the tower plate 26 at each opening 29 is provided with an upwardly extending baffle plate 12, the openings 29 between two adjacent tower plates 26 are arranged oppositely, the top surface of each tower plate 26 is provided with a spiral groove 32, the bottom of each spiral groove 32 is provided with a plurality of water leakage holes 33 at intervals, a packing layer A7 is arranged in the common rectifying section 3, a packing layer B17 is arranged in the common stripping section 18, a disc distributor B16 is arranged in the common stripping section 18 between the packing layer B17 and the cylinder body 27, a C-shaped pipe 30 is sleeved in the middle of the outer wall of the tower body 11, a pipe cavity is arranged in the C-shaped pipe 30, a feed pipe 24 penetrating through the pipe cavity is arranged in the middle of the outer edge of the C-shaped pipe 30, a preheater 25 is arranged on the feed pipe 24, connecting pipes 31 penetrating through the pipe cavity and the middle of the outer cylinder rectifying feed section 23 are arranged between the middle and two ends of the inner edge of the C-shaped pipe 30 and the outer wall of the tower body 11, the three connecting pipes 31 are arranged around the tower body 11 at equal intervals, an annular A10 is arranged in the outer cylinder rectifying feed section 23 above the packing layer 31, an annular distributor A9 is arranged in an outer barrel rectification feeding section 23 between an annular packing layer A10 and the upper end of a barrel body 27, an annular packing layer B28 is arranged in the outer barrel rectification feeding section 23 below a connecting pipe 31, an annular distributor B15 is arranged in the outer barrel rectification feeding section 23 between the annular packing layer B28 and the connecting pipe 31, one end of an inner barrel extraction pipe 13 penetrates through the outer barrel rectification feeding section 23 along the outer wall of a tower body 11 and then is communicated with the middle lower part of an inner barrel lateral line extraction section 14, the top of the tower body 11 is connected with one end of a tower top outlet pipe 1, the other end of the tower top outlet pipe 1 is respectively connected with one end of a tower top return pipe 5 and one end of a tower top discharge pipe 4, a condenser 2 is arranged on the tower top outlet pipe 1, the other end of the tower top return pipe 5 is connected to the tower body 11 above the packing layer A7, a disc distributor A6 is arranged on a common rectification section 3 between the tower top return pipe 5 and the packing layer A7, the lower end of the tower body 11 is connected with one end of a tower bottom liquid outlet pipe 22, the other end of the tower bottom liquid outlet pipe 22 is respectively connected with one end of a tower bottom production pipe 21 and one end of a tower bottom return pipe 19, the tower bottom return pipe 19 is provided with a reboiler 20, and the other end of the tower bottom return pipe 19 is connected on the tower body 11 below a packing layer B17.

When the inner barrel rectifying tower for separating the mixed fraction of the C12-C15 normal paraffin is implemented, the condenser 2, the reboiler 20 and the preheater 25 are connected with a switch and a power supply, the condenser 2, the reboiler 20 and the preheater 25 are started, the mixed raw material of the C12-C15 normal paraffin is heated from the feeding pipe 24 through the preheater 25 for flash separation, and then is fed to the outer barrel rectifying feeding section 23 through the C-shaped pipe 30 along the three connecting pipes 31 simultaneously, so that uniform feeding is realized, the separated gas C12 and C13 rise along the outer barrel rectifying feeding section 23, and the separated liquid C14 and C15 fall along the outer barrel rectifying feeding section 23;

ascending gaseous C12 and C13 reach a common rectification section 3 after contacting and separating with a liquid phase which is uniformly distributed and descends in an annular packing layer A10 and an annular distributor A9, join with a gas phase which is ascending in an inner cylinder side line extraction section 14, reflux and contact and separate with a descending liquid phase which is uniformly distributed in a disc distributor A6 in the packing layer A7, the gas phase is led out from a tower top gas outlet pipe 1, after being condensed by a tower top condenser 2, a part of C12 is taken out as a tower top product through a tower top discharge pipe 4, a part of C12 is taken as a tower top reflux and returns into the tower through a tower top reflux pipe 5, after contacting and separating with the ascending gas phase in the packing layer A7, the gas phase respectively flows into an inner cylinder side line extraction section 14 and an outer cylinder rectification feed section 23, the liquid phase flowing into the inner cylinder side line extraction section 14 is rapidly separated with the ascending gas phase on a tower plate 26, and the part of the inner cylinder extraction pipe 13 arranged at the lower part of the inner cylinder side line extraction section 14 is taken out, the produced material is mainly C13;

descending liquid C14 and C15 are uniformly distributed by an annular distributor B15, then reach a common stripping section 18 after being in contact separation with ascending gas phase in an annular packing layer B28, are converged with the descending liquid phase in an inner cylinder side line extraction section 14, are uniformly distributed by a disc distributor B16 in a packing layer B17 and are in countercurrent contact separation with ascending gas phase at the tower bottom, the liquid phase is led out by a tower bottom liquid outlet pipe 22, a part of the liquid phase C15 is taken out as a tower bottom product through a tower bottom extraction pipe 21, a part of the liquid phase C15 is heated by a tower bottom reboiler 20 to become gas phase, returns into the tower through a tower bottom return pipe 19, is respectively lifted into an inner cylinder side line extraction section 14 and an outer cylinder rectification feeding section 23 after the packing layer B17 is in contact separation with the descending liquid phase, the gas phase lifted into the inner cylinder side line extraction section 14 is quickly extracted from an inner cylinder extraction pipe 13 arranged at the lower part of the inner cylinder side line extraction section 14 after the gas phase is in contact separation with the descending liquid phase through a tower plate 26, the produced material is mainly C14;

the process employs a dividing wall rectifying column designed as described in the above invention. According to theoretical calculation, under the feeding quantity of 2500kg/h, the invention only needs 57 layers of theoretical plates, under the pressure of the top of the tower of 0.05 KPa/the pressure of the bottom of the tower of 0.55KPa, the reflux quantity is 900kg/h, the separation effect on the ternary components (C12: C13/C14: C15= 23%: 45%: 32%) is good, and the purity of C12 and C15 products reaches more than 99.95%.

The present invention is not described in detail in the prior art.

Claims

1. A rectifying tower with an inner barrel for separating mixed fractions of C12-C15 normal paraffins is characterized in that: comprises a tower body (11), a cavity is arranged in the tower body (11), a vertically arranged cylinder body (27) is arranged in the middle of the cavity, the cavity is divided into four parts by the cylinder body (27), the cavity above the cylinder body (27) forms a public rectifying section (3), the cavity below the cylinder body (27) forms a public stripping section (18), the cavity between the cylinder body (27) and the tower body (11) forms an outer cylinder rectifying feeding section (23), an inner cylinder side line extracting section (14) with an opening at the upper end and a lower end is arranged in the cylinder body (27), a plurality of tower plates (26) are arranged in the inner cylinder side line extracting section (14) at intervals, each tower plate (26) is provided with a notch (29), the notches (29) between two adjacent tower plates (26) are oppositely arranged, the top surface of each tower plate (26) is provided with a spiral groove (32), a plurality of water leakage holes (33) are arranged at intervals at the bottom of each spiral groove (32), a packing layer A (7) is arranged in the public rectification section (3), a packing layer B (17) is arranged in the public stripping section (18), a C-shaped pipe (30) is sleeved in the middle of the outer wall of the tower body (11), a pipe cavity is arranged in the C-shaped pipe (30), a feeding pipe (24) which penetrates through the pipe cavity is arranged in the middle of the outer edge of the C-shaped pipe (30), a preheater (25) is arranged on the feeding pipe (24), connecting pipes (31) which penetrate through the pipe cavity and the middle of the outer barrel rectification feeding section (23) are respectively arranged between the middle and two ends of the inner edge of the C-shaped pipe (30) and the outer wall of the tower body (11), the three connecting pipes (31) are equidistantly arranged around the tower body (11), an annular packing layer A (10) is arranged in the outer barrel rectification feeding section (23) which is positioned above the connecting pipes (31), and an annular packing layer B (28) is arranged in the outer barrel rectification feeding section (23) which is positioned below the connecting pipes (31), one end of the inner cylinder extraction pipe (13) penetrates through the outer cylinder rectification feeding section (23) along the outer wall of the tower body (11) and then is communicated with the middle lower part of the inner cylinder lateral line extraction section (14).

2. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: the top of tower body (11) is connected the one end of top of the tower outlet duct (1), and the other end of top of the tower outlet duct (1) connects each one end of top of the tower back flow pipe (5) and top of the tower discharging pipe (4) respectively, is equipped with condenser (2) on top of the tower outlet duct (1), and the other end of top of the tower back flow pipe (5) is connected on tower body (11) that is located packing layer A (7) top, is equipped with disc distributor A (6) on public rectifying section (3) between top of the tower back flow pipe (5) and packing layer A (7).

3. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: the lower end of the tower body (11) is connected with one end of a tower bottom liquid outlet pipe (22), the other end of the tower bottom liquid outlet pipe (22) is respectively connected with one end of a tower bottom production pipe (21) and one end of a tower bottom return pipe (19), a reboiler (20) is arranged on the tower bottom return pipe (19), and the other end of the tower bottom return pipe (19) is connected on the tower body (11) below the packing layer B (17).

4. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: the edge of the tower plate (26) at each gap (29) is provided with a baffle plate (12) extending upwards.

5. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: a disc distributor B (16) is arranged in the common stripping section (18) between the packing layer B (17) and the barrel (27).

6. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: an annular distributor A (9) is arranged in an outer barrel rectification feeding section (23) between the annular packing layer A (10) and the upper end of the barrel body (27).

7. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: an annular distributor B (15) is arranged in the outer barrel rectifying feed section (23) between the annular packing layer B (28) and the connecting pipe (31).

8. The in-band cylindrical rectification column for the separation of mixed fraction of C12-C15 normal paraffins as set forth in claim 1, wherein: a plurality of connecting rods (8) are fixedly connected between the cylinder (27) and the tower body (11).