JP4796736B2 - Rectification equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rectification apparatus and a rectification method using the same.
[Prior art]
[0002]
In the organic chemical industry, the petroleum industry, and the like, a rectifying apparatus is generally used for separating a part of volatile components from a raw material containing a plurality of components. This rectifying apparatus is generally as shown in FIG.
[0003]
The rectification apparatus 41 shown in FIG. 4 is discharged from the rectification tower 42 including the counterflow gas-liquid contact parts 12 and 12 and the tower top 43 filled with Raschig rings and the like, and sent from the tower top 43 through a pipe 45. A condenser 46 for condensing the vapor, a reflux tank 47 for storing the reflux liquid 48 condensed by the condenser 46, and a reflux liquid 48 discharged from the reflux tank 47 through a pipe 49. Alternatively, the pump 50 is fed to the pipe 53 and the reboiler 26 is used to heat the liquid discharged from the rectifying column 42.
[0004]
In the rectifying apparatus 41, the raw material is supplied into the rectifying tower 42 through the raw material supply pipe 22. The supplied raw material flows down in the countercurrent gas-liquid contact portion 12 and is discharged from the tower bottom 23 through the pipe 24. A part of the discharged raw material is collected through the pipe 28, and the rest is sent to the reboiler 26, heated by the reboiler 26, and a part thereof is vaporized and supplied to the tower bottom 23 through the pipe 27. . The supplied steam rises in the counterflow gas-liquid contact parts 12 and 12 while making countercurrent contact with the raw material and the reflux liquid, and is discharged from the steam outlet 44 of the tower top part 43. A part of the discharged steam passes through the condenser 46, the reflux tank 47 and the pump 50, and a part thereof is supplied as a reflux liquid to the tower top 43 through the pipe 51, and the rest is recovered as a distillate through the pipe 53. The ratio of the reflux liquid to the distillate is adjusted by adjusting valves 52 and 54.
[0005]
However, when performing rectification using the rectification apparatus 41 shown in FIG. 4, there are the following problems.
(1) Between the rectifying column 42 and the condenser 46, a reflux tank 47, a pump 50, and reflux facilities such as pipes 45, 49, 51, and 53 for connecting them are necessary. In particular, it is difficult to accurately maintain the temperature in the rectification apparatus 41 at a predetermined temperature with the accuracy required when rectifying a substance sensitive to temperature changes.
{Circle around (2)} Since the pump 50 is used to send the reflux liquid condensed by the condenser 46, there is a possibility that machine oil, water, etc. are mixed into the reflux liquid from the pump 50 and the reflux liquid is contaminated.
(3) Since there are many parts, it takes time to clean and inspect when changing the product type. For this reason, it is not suitable for rectification of small quantities and many varieties.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a rectification apparatus having a simple structure and a rectification method using the same, which does not require a reflux facility such as a reflux pump that causes contamination.
[0007]
[Means for Solving the Problems]
A rectifying apparatus according to the present invention for solving the above problems includes a rectifying column having a countercurrent gas-liquid contact portion, and a condenser attached to an upper end of a top of the rectifying column. At the top of the tower is formed a substantially horizontal portion in which a part of the tower top is bent, and the substantially horizontal portion is provided with a weir for blocking the reflux liquid flowing down from the condenser, A liquid reservoir for storing the reflux liquid is formed by the substantially horizontal portion and the weir, and the reflux liquid stored in the liquid reservoir is configured to be extracted as a rectified fraction.
[0008]
The rectification method using the rectification apparatus of the present invention is a rectification method using the rectification apparatus, wherein the vapor generated in the rectification tower is guided from the top of the rectification tower to the condenser, Condensed in the condenser and allowed to flow down as a reflux liquid from the condenser. A part of the reflux liquid is extracted from the liquid reservoir as a fraction.
[0009]
This eliminates the need for a recirculation facility such as a pump that has conventionally been necessary for recirculation, thereby preventing foreign matters from being mixed into the recirculation liquid. In addition, the equipment required for reflux such as piping and reflux tanks is greatly reduced and simplified, so that cleaning and inspection work when changing the product type is facilitated.
[0010]
In particular, since the rectification method of the present invention has a simple structure without a reflux facility such as a pump, it is easy to accurately maintain the temperature in the rectification apparatus at a predetermined temperature and is sensitive to temperature changes. For example, a substance that is easily thermally degraded such as being colored or thermally decomposed by heat, a substance having a very small difference between the boiling point and the melting point, a substance that self-heats, specifically, a peroxide, an organometallic compound, etc. Suitable for purifying amines.
[0011]
In the rectification apparatus of the present invention, a notch may be provided at the upper end of the weir, and the reflux liquid stored in the liquid reservoir may be configured to overflow from the notch. The reflux liquid overflowing from the notch is returned to the counter-current gas-liquid contact part. The flow rate of the reflux liquid is easily obtained from the liquid level of the V-shaped or U-shaped notch, for example. be able to. That is, by observing the liquid level in the liquid reservoir visible from the V-shaped or U-shaped notch, the amount of the reflux liquid stored in the liquid reservoir can be detected. From this amount of liquid, it is possible to grasp the flow rate of the reflux liquid that overflows and flows down to the countercurrent gas-liquid contact portion. Therefore, the notch also serves as a flowmeter for the reflux liquid. As described above, when the notch serves as a flow meter, problems such as a failure that occurs when a normal flow meter is used do not occur. In addition, the liquid level height which can be seen from the above-mentioned notch part can be measured, for example, by providing a viewing window at a part of the tower top and observing from this window. Furthermore, the amount of steam cooked can be grasped from the amount of the reflux liquid detected.
[0012]
In the rectification apparatus of the present invention, a tub for supplying the reflux liquid overflowing from the weir to the vicinity of the center of the cross section of the countercurrent gas-liquid contact portion may be attached to the weir. Thereby, since the reflux liquid is supplied near the center of the upper surface of the countercurrent gas-liquid contact portion, the contact efficiency between the steam and the liquid can be improved.
[0013]
In the rectification method of the present invention, since the total reflux can be performed with the liquid extraction valve closed, a high-purity distillate can be easily obtained.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a rectification apparatus 11 according to an embodiment of the present invention. In addition, about the same structural member as the rectification tower 41 of FIG. 4, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0015]
As shown in FIG. 1, the rectifying apparatus 11 includes a rectifying column 13 and a condenser 16 attached to the upper end of the column top 14 of the rectifying column 13. A substantially horizontal portion 15 in which a part of the tower top portion 14 is bent is formed, and the substantially horizontal portion 15 is provided with a weir 17 for blocking the reflux liquid 19 flowing down from the condenser 16. 15 and the weir 17 form a liquid reservoir 18 for storing the reflux liquid 19, and the reflux liquid 19 stored in the liquid reservoir 18 can be extracted as a fraction through a liquid discharge valve 21. The liquid discharge valve 21 is provided at the lower portion of the outer peripheral surface of the substantially horizontal portion 15 in which the liquid reservoir portion 18 is formed.
[0016]
FIG. 2 is an enlarged cross-sectional view of the vicinity of the liquid extraction valve 21. The liquid discharge valve 21 shown in FIG. 2 is composed of a valve seat 21b and a valve body 21a provided at the bottom of the liquid reservoir 18, and by pulling up the valve body 21a fitted to the valve seat 21b, The liquid discharge valve 21 can be opened. Thereby, a part of the reflux liquid 19 can be extracted from the liquid extraction valve 21.
[0017]
As the liquid discharge valve 21, in addition to the valve shown in FIG. 2, a gate valve, a slide valve, a ball valve, a flush valve, or the like can be used. It may be a pneumatic type that operates, or an electromagnetic type that operates electrically.
[0018]
The tower top portion 14 has a portion bent from the vertical to substantially horizontal and a portion bent from substantially horizontal to vertical, and a substantially horizontal portion 15 is formed between these bent portions. Is done. For example, the bent portion may be formed by connecting a cylindrical tube to both ends using a 90 ° elbow tube, or the tower top portion 14 having the two bent portions may be used by integral molding.
[0019]
Here, “substantially horizontal” means that the axis of the substantially horizontal portion 15 may be perpendicular to or close to the axis of the rectifying column 13. Specifically, the axis of the substantially horizontal portion 15 is preferably about 90 ° ± 20 ° with respect to the axis of the rectifying column 13.
[0020]
As the condenser 16, a condenser such as a multi-tube type, a coil type, or a spiral type can be used.
[0021]
FIG. 3 is a partially broken perspective view schematically showing the vicinity of the liquid reservoir 18. As shown in FIG. 3, a V-shaped notch 17 a is provided at the upper end of the weir 17 that dams the reflux liquid 19. The height h from the lower end (V-shaped lower end) of the notch 17a to the liquid level of the reflux liquid 19 is observed and measured from the observation window 20 provided on the wall surface of the tower top 14 to measure the liquid pool. The amount of the reflux liquid 19 stored in the unit 18 can be detected, and the flow rate of the reflux liquid 19 that overflows and flows down to the countercurrent gas-liquid contact unit 12 and the amount of steam cooked from the liquid amount can be detected. It can be measured. The relationship between the height h, the amount of liquid, the flow rate, and the amount of cooking is related in advance by actual measurement or calculation.
[0022]
In order to minimize the increase in pressure loss in the flow path due to the weir 17, the area excluding the liquid reservoir 18 out of the cross-sectional area of the substantially horizontal portion 15 is the crossing of the countercurrent gas-liquid contact portion 12. The surface area may be 0.5 times or more, preferably 0.8 times or more, usually 2 times or less, preferably 1.2 times or less. Further, the cutout length of the cutout portion 17a may be determined according to the flow rate of the reflux liquid 19 overflowing, the capacity of the liquid reservoir portion 18, and the like.
[0023]
In order to further reduce the pressure loss, it is preferable to make the space section cross-sectional area of the entire tower top portion 14 substantially equal. For this purpose, the inner diameter of the substantially horizontal portion 15 whose space cross-sectional area is narrowed by the weir 17 may be increased.
[0024]
Further, a trough 29 is attached to the lower portion of the notch 17 a in the weir 17. The trough 29 is for supplying the reflux liquid 19 overflowing from the notch portion 17 a to the vicinity of the center of the upper surface of the counterflow gas-liquid contact portion 12. The length, attachment angle, and the like of the ridge 29 are adjusted so that the reflux liquid 19 flowing out from the tip of the ridge 29 flows down to the vicinity of the center of the upper surface of the counterflow gas-liquid contact portion 12.
[0025]
As shown in FIGS. 1 and 3, the rectification apparatus 11 of the present invention has few obstacles such as protrusions in the tower top portion 14 and a wide gas flow path, so that pressure loss is small and heat loss is minimized. ing. Thus, since there is little heat loss, it is easy to maintain the temperature in the rectification apparatus 11 at a predetermined temperature with high accuracy, and the heat retention management accuracy is improved. This facilitates rectification and separation of substances sensitive to temperature changes. However, if necessary, a heater or jacket for keeping warm or heating may be attached to the outer peripheral surface of the tower top 14.
[0026]
Examples of substances sensitive to temperature changes include polymerizable compounds, amines, organometallic compounds, peroxides, and the like.
[0027]
In order to perform rectification using the rectifying apparatus 11 as described above, the vapor generated in the rectifying column 13 is led from the top 14 of the rectifying column 13 to the condenser 16 and condensed and condensed by the condenser 16. The reflux liquid 19 flowing down from the vessel 16 is accumulated in the liquid reservoir 18, overflowing from the liquid reservoir 18 and refluxed to the countercurrent gas-liquid contact section 12, and the liquid extraction valve 21 is intermittently opened to collect the liquid. The reflux liquid 19 is extracted from the part 18 and recovered as a distillate.
[0028]
That is, since the reflux liquid 19 is fully refluxed when the liquid discharge valve 21 is closed, the longer the time during which the liquid discharge valve 21 is closed, the more the purity of the distillate can be improved. it can. Therefore, a high-purity distillate with few impurities can be obtained by adjusting the closing time of the liquid discharge valve 21.
[0029]
The rectifying apparatus of the present invention may be a plate tower or the like in addition to the packed tower as shown in the above embodiment. Moreover, the number of stages of the packed tower or the tray tower is not particularly limited.
[0030]
【The invention's effect】
Since the rectification apparatus of the present invention does not require equipment such as a reflux pump that causes foreign matters to be mixed into the reflux liquid, it can prevent the distillate from being contaminated, and can be substantially horizontal at the top of the column. Since it has a simple structure in which the liquid reservoir is simply provided in the part, it is possible to reduce the size and to easily disassemble the product during product change or maintenance. Moreover, since the rectifying apparatus of the present invention has a simple structure without a reflux facility such as a pump, it is easy to accurately maintain the temperature in the rectifying apparatus at a predetermined temperature, and the heat retention management accuracy is high. There is an effect of improving.
[0031]
Further, in the present invention, when a reed for overflowing the reflux liquid overflowing from the notch to the vicinity of the center of the upper surface of the countercurrent gas-liquid contact part of the rectification tower is attached to the weir, Is supplied in the vicinity of the center of the upper surface of the counter-current gas-liquid contact portion, so that the contact efficiency between the vapor and the liquid can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a rectification apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of the vicinity of a liquid extraction valve of a rectifying apparatus according to the present invention.
FIG. 3 is a partially broken perspective view schematically showing the vicinity of a liquid pool portion of the rectifying apparatus according to the present invention.
FIG. 4 is a schematic view showing an example of a conventional rectification apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Rectification apparatus, 12 ... Counterflow gas-liquid contact part, 13 ... Rectification tower, 14 ... Tower top part, 15 ... Substantially horizontal part, 16 ... Condenser, 17 ... Weir, 17a ... Notch, 18 ... Liquid reservoir, 19 ... Recirculating liquid, 21 ... Liquid extraction valve, 21a ... Valve body, 21b ... Valve seat, 22 ... Raw material supply piping, 23 ... Tower bottom, 24 ... Tower bottom piping, 25 ... Piping, 26 ... Reboiler, 27 ... Piping, 28 ... Piping, 29 ... 樋

Claims (2)

A rectifying column having a counter-current gas-liquid contact portion and a condenser attached to the upper end of the top of the rectifying column are provided, and a part of the top of the column is bent at the top of the rectifying column. A substantially horizontal portion is formed, and the substantially horizontal portion is provided with a weir for blocking the reflux liquid flowing down from the condenser, and a liquid reservoir portion for collecting the reflux liquid by the substantially horizontal portion and the weir. Formed and configured to extract the reflux liquid stored in the liquid reservoir as a fraction .
A notch is provided at the upper end of the weir, and the reflux liquid stored in the liquid reservoir is configured to overflow from the notch,
Further, a rectifier for supplying the reflux liquid overflowing from the weir to the vicinity of the center of the cross section of the countercurrent gas-liquid contact portion is attached to the weir . It is a rectification method using the rectification apparatus of Claim 1, Comprising: The vapor | steam which generate | occur | produced in the said rectification column is guide | induced to the said condenser from the tower top part of a rectification tower, is condensed with the said condenser, and is made into a reflux liquid As a result, the reflux liquid flowing down from the condenser is accumulated in the liquid reservoir at the top of the column, overflowed from the liquid reservoir and refluxed to the countercurrent gas-liquid contact part, and part of the reflux liquid was rectified. A rectification method characterized by being extracted from a liquid reservoir as a fraction.

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