JP4189075B2 - Distillation equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a condensing tube provided at the top of a distillation column is immersed in a refrigerant liquid in a refrigerant liquid tank to condense the condensable gas that has risen from the distillation column, and the produced condensate is naturally distilled into the distillation column. The present invention relates to a distillation apparatus to be refluxed .
[0002]
[Prior art]
In a distillation apparatus having a structure in which a large number of distillation columns are assembled, a condensing tube provided at the top of each distillation column is immersed in the refrigerant liquid in the refrigerant liquid tank to condense and generate the condensable gas rising from the distillation column. A condenser having a configuration in which the condensate is refluxed to the distillation column under a natural flow may be employed.
[0003]
[Problems to be solved by the invention]
The capacitor having such a configuration has a simple configuration depending on natural convection of the refrigerant liquid in the refrigerant liquid tank and heat exchange in the cylindrical wall of the condenser tube, and it is difficult to say that the heat transfer performance is high. In particular, with a refrigerant liquid having a small temperature difference from the condensable gas, it is difficult to obtain heat transfer performance necessary for condensation. On the other hand, it is possible to obtain the required heat transfer performance by increasing the capacity of the capacitor, but in this case, an increase in the size of the equipment, that is, an increase in cost is inevitable.
[0004]
The present invention has been devised to solve such problems of the prior art, and its main purpose is to ensure sufficient heat transfer performance even if the temperature difference between the refrigerant and the condensable gas is slight. Another object of the present invention is to provide a distillation apparatus configured to be able to do this.
[0005]
[Means for Solving the Problems]
In order to achieve such an object, in the present invention, a distillation column extending in the vertical direction and provided side by side, a condenser provided at the upper portion of the distillation column, and a lower portion of the distillation column are provided. The reboiler provided is housed in one heat insulating container, and in the condenser, a condenser tube provided at the top of each of the plurality of distillation columns is immersed in a refrigerant liquid in a refrigerant liquid tank, and the distillation column In a distillation apparatus that condenses the condensable gas that has risen from above and recirculates the generated condensate to the distillation column under natural flow, the condensate tube that extends in the vertical direction is coaxially expanded in diameter. In addition to providing the enlarged diameter portion, a plurality of upper and lower inner pipes through which the refrigerant liquid can flow are provided in the enlarged diameter portion.
[0006]
According to this, an upward flow is generated in the refrigerant liquid in the inner tube by the thermosiphon action, and the inner tube functions as a heat transfer tube. This makes it possible to secure a large heat transfer area without increasing the capacity of the capacitor, and when it is difficult to obtain a large temperature difference between the refrigerant and the condensable gas, such as when performing distillation operations at extremely low temperatures. In addition, sufficient heat transfer performance can be ensured.
[0007]
In particular, the refrigerant liquid should have a boiling point below the condensing point of the condensable gas and should boil by heat exchange with the condensable gas. According to this, bubbles generated by the boiling of the refrigerant liquid The rise causes a gas lift effect that pushes up the refrigerant liquid in the inner pipe, increasing the refrigerant liquid flow rate in the inner pipe and greatly improving the heat transfer coefficient on the nucleate boiling side, thereby obtaining high heat transfer performance. Can do.
[0008]
In addition, a part of the enlarged diameter portion is exposed from the refrigerant liquid level in the refrigerant liquid tank, and a wetted wall is formed in a range from the opening portion of the inner tube to the refrigerant liquid level on the exposed surface of the enlarged diameter portion. The amount of heat transfer should be controlled by adjusting the liquid level of the refrigerant liquid to increase / decrease the area of the wetted wall , and according to this, the amount of heat transfer can be greatly increased. The amount of heat transfer can be controlled by adjusting the liquid level of the refrigerant liquid to increase or decrease the area of the wet wall. Even if a part of the enlarged diameter part is exposed from the refrigerant liquid surface and the upper opening of the inner pipe is opened in the gas phase, the refrigerant liquid overflows from the upper opening of the inner pipe due to the gas lift effect due to the boiling of the refrigerant liquid, As the refrigerant liquid flows down along the outer surface of the enlarged diameter portion, a wet wall is formed on the outer surface of the enlarged diameter portion.
[0009]
In addition, the inner tube preferably has fins on the outer peripheral surface, and according to this, the heat transfer performance can be further enhanced by increasing the heat transfer area.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a configuration of the present invention will be described in detail with reference to the accompanying drawings.
[0011]
FIG. 1 shows a schematic configuration of a distillation apparatus according to the present invention. This distillation apparatus performs a distillation operation under a temperature condition of room temperature or lower, and includes a condenser 1, a plurality of distillation columns 2 filled with a filler, and a reboiler 3 that heats and evaporates the condensate in one heat insulating container. 4 is housed. The condenser 1, the distillation column 2 and the reboiler 3 are supported by the heat insulating container 4 via a support member (not shown).
[0012]
In the condenser 1, a condenser tube 5 provided at the upper end of each distillation column 2 is immersed in a refrigerant liquid in a condenser container 6 serving as a refrigerant liquid tank, and condensable gas rising from the distillation column 2 is condensed. Yes. The condensate produced in the condensing tube 5 is naturally flowed and returned to the distillation column 2. Here, in the reboiler 3, the liquid staying in the reboiler container 7 is heated by the electric heater 8 operated by the power source 9. The to-be-distilled material is sent to the middle stage of the distillation column 2, and the low-boiling components are extracted from the top of the condenser tube 5 and the high-boiling components are extracted from the reboiler vessel 7.
[0013]
The condensing tube 5 of the condenser 1 is provided with an enlarged diameter portion 10. If the enlarged diameter portion 10 is formed in the gap of the condenser tube 5 arranged at a predetermined interval from the relationship of the assembling work of the distillation column 2 or the like, the condenser 1 does not substantially increase in volume.
[0014]
As shown in detail in FIG. 2, a plurality of upper and lower inner pipes 11 through which the refrigerant liquid in the capacitor container 6 can flow are provided in the enlarged diameter portion 10 of the condensing pipe 5. The enlarged diameter portion 10 includes a cylindrical portion 12 that is coaxial with the condensing tube 5 and upper and lower end plates 13 and 14 that close the end openings thereof, and is constructed between the upper and lower end plates 13 and 14. In this manner, the inner tube 11 is provided, and the inside of the inner tube 11 is opened into the liquid phase from the upper and lower openings. Here, as shown in FIG. 3, a plurality of inner tubes 11 are arranged in the circumferential direction around the axis of the condensing tube 5. As shown in FIG. 4, the inner tube 11 may be provided with fins 15 protruding in the radial direction from the outer peripheral surface.
[0015]
In the capacitor 1 configured as described above, as indicated by an arrow in FIG. 2, an upward flow is generated in the refrigerant liquid in the inner tube 11 by the thermosiphon action, and the inner tube 11 functions as a heat transfer tube, Cold heat is transmitted from the outer surface of the inner tube 11 and the inner surface of the enlarged diameter portion 10 to the condensable gas.
[0016]
Further, when the refrigerant liquid has a boiling point lower than the condensing point of the condensable gas, for example, when the condensable gas is methane, when liquefied nitrogen or liquefied methane is used as the refrigerant, the refrigerant is exchanged by heat exchange with the condensable gas. The liquid is boiled, and the rise of bubbles generated by the boiling of the refrigerant liquid causes a gas lift effect that pushes the refrigerant liquid in the inner pipe 11 upward, and the amount of refrigerant liquid in the inner pipe 11 increases.
[0017]
As shown in FIG. 2, when the enlarged diameter portion 10 is completely immersed, it is difficult to control the heat transfer amount because the heat transfer amount is governed by the rising speed of the bubbles in the inner tube 11. On the other hand, as shown in FIG. 5, a part of the enlarged diameter portion 10 is exposed from the refrigerant liquid surface A in the capacitor container 6, and the refrigerant liquid is exposed from the opening portion of the inner tube 11 on the exposed surface of the enlarged diameter portion 10. If the wetting wall B is formed in the range reaching the surface A, the heat transfer amount can be greatly increased, and the heat transfer amount can be controlled by increasing / decreasing the area of the wetting wall B by adjusting the refrigerant liquid surface A. Become. Even if the enlarged diameter portion 10 is partially exposed from the refrigerant liquid level A and the upper opening of the inner pipe 11 is opened to the gas phase, the refrigerant liquid is discharged from the upper opening of the inner pipe 11 due to the gas lift effect due to the boiling of the refrigerant liquid. Overflows and the refrigerant liquid flows down along the outer surface of the enlarged diameter portion 10 to form a wet wall B here.
[0018]
【The invention's effect】
As described above, according to the present invention, a large heat transfer area can be ensured without increasing the capacity of the condenser so that the temperature difference between the refrigerant and the condensable gas can be reduced as in the case of performing a distillation operation at a very low temperature. Even when it is difficult to obtain a large size, sufficient heat transfer performance can be ensured.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a distillation apparatus according to the present invention.
FIG. 2 is an enlarged vertical sectional view of the capacitor shown in FIG.
3 is an enlarged cross-sectional view of the capacitor shown in FIG.
FIG. 4 is a cross-sectional view showing an example in which fins are provided in an inner tube of a capacitor.
5 is a cross-sectional view similar to FIG. 2, showing a state in which a wetting wall is formed on the capacitor shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Capacitor 2 Distillation column 3 Reboiler 4 Thermal insulation container 5 Condensation pipe 6 Condenser container 7 Reboiler container 8 Electric heater 9 Power supply 10 Diameter expansion part 11 Inner pipe 12 Cylindrical part 13/14 End plate 15 Fin A Refrigerant liquid level B Wetting wall

Claims (4)

A distillation column extending in the vertical direction and arranged side by side, a condenser provided at the top of the distillation column, and a reboiler provided at the bottom of the distillation column are accommodated in one heat insulating container. Te becomes, in the capacitor, by immersing the plurality of condensing tubes arranged respectively at the top of the distillation column to the refrigerant liquid in the coolant liquid tank, the condensate produced with condensing elevated condensable gases from the distillation column Is a distillation apparatus in which the water is recirculated to the distillation column under natural flow,
The condensing pipe extending in the up-down direction is provided with a diameter-expanding portion having an aspect in which it is coaxially expanded, and an inner pipe in the up-down direction through which the refrigerant liquid in the refrigerant liquid tank can flow is provided in the enlarged-diameter portion. A distillation apparatus characterized in that a plurality of distillation apparatuses are provided. Distillation apparatus according to claim 1, wherein the refrigerant liquid has a boiling point of below the condensation point of the condensable gas, characterized in that the heat exchange with the condensable gas is intended to cause boiling. A part of the enlarged diameter portion is exposed from the refrigerant liquid level in the refrigerant liquid tank, and a wetted wall is formed in a range from the opening portion of the inner tube to the refrigerant liquid level in the exposed surface of the enlarged diameter portion ;
Distillation apparatus according to claim 2, characterized in that so as to control the heat transfer by increasing or decreasing the area of the wetted wall by adjusting the liquid level of the refrigerant liquid. The distillation apparatus according to any one of claims 1 to 3, wherein fins are provided on an outer peripheral surface of the inner tube.

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