CN-121988060-A - Sub-boiling distillation device utilizing constant boiling heat supply

CN121988060ACN 121988060 ACN121988060 ACN 121988060ACN-121988060-A

Abstract

The invention discloses a sub-boiling distillation device utilizing constant boiling heat supply, and belongs to the technical field of distillation and purification. Comprises an azeotropic evaporation part, a sub-boiling distillation part nested in the azeotropic chamber, a condensate circulation control part and an integrated jacket structure. The constant boiling evaporation is utilized to supply heat, the sub-boiling state is automatically maintained through the temperature gradient without complex temperature control, secondary pollution is avoided through the cooperative control of the non-contact liquid level sensor and the condensate buffer tank, the evaporation temperature can be accurately controlled by adjusting the pressure or changing the constant boiling area, and the double-stage distillation device has the double modes of single sub-boiling and continuous two-stage distillation. Surface area enhancement inner members can be additionally arranged in the sub-boiling chamber, a liquid column is formed by utilizing surface tension, and the distillation efficiency is obviously improved. The invention has simple structure, high heat efficiency and good purification effect, and is suitable for preparing high-purity reagents in laboratories.

Inventors

XI ZHENHAO
ZHAO LING
HUANG HUAN
CHEN TIANJIAO
QIU XIAOYI
GUO QINSHENG
HU DONGDONG
YU ZEYU
WANG YUFEI

Assignees

华东理工大学

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. The sub-boiling distillation device utilizing constant boiling heat supply is characterized by comprising a constant boiling evaporation part, wherein the constant boiling evaporation part comprises a constant boiling chamber (1), a constant boiling condenser (3), an electric heating table (12), a feed valve (7), a condensate reflux valve (6) and a non-contact capacitance liquid level sensor (10), the electric heating table (12) is arranged at the bottom of the constant boiling chamber (1) for heating, the feed valve (7) is arranged at the upper part of the constant boiling chamber (1) for supplementing liquid, the condensate reflux valve (6) is arranged at the top of the constant boiling chamber (1) for regulating the pressure in the chamber, and the non-contact capacitance liquid level sensor (10) is attached to the outer wall of the constant boiling chamber (1) for non-contact detection of liquid level; The device comprises a sub-boiling distillation part, a temperature probe (14) and a liquid collecting bottle, wherein the sub-boiling distillation part comprises a sub-boiling chamber (2), a sub-boiling condenser (8) and a liquid collecting bottle (9), the top of the sub-boiling chamber (2) is respectively provided with an interface communicated with an outlet of a condensate buffer tank (4), a steam outlet interface communicated with an inlet of the sub-boiling condenser (8) and an interface for installing the temperature probe (14), the temperature probe (14) is arranged at the interface at the top of the sub-boiling chamber (2) and is used for monitoring the temperature of steam in the sub-boiling chamber (2), the sub-boiling condenser (8) is connected with a steam outlet of the sub-boiling chamber (2), and the outlet of the sub-boiling condenser is connected with the liquid collecting bottle (9); The constant-boiling condenser comprises a constant-boiling condenser body, a condensate circulation control part, a constant-boiling condenser body and a liquid storage device, wherein the condensate circulation control part comprises a condensate buffer tank (4), a condensate outlet valve (5) and a condensate reflux valve (6), the bottom outlet of the constant-boiling condenser body (3) is connected with the top inlet of the condensate buffer tank (4), two paths of outlets are respectively arranged at the bottom of the condensate buffer tank (4), one path of outlets is connected to the top interface of the sub-boiling chamber (2) through the condensate outlet valve (5), and the other path of outlets is connected to the constant-boiling chamber (1) through the condensate reflux valve (6); The sub-boiling chamber (2) is nested and fixed in the constant boiling chamber (1) through the integrated jacket structure, so that the evaporation part of the sub-boiling chamber (2) is completely immersed in boiling liquid and steam atmosphere in the constant boiling chamber (1), the temperature gradient of heat transfer is used for automatically controlling the temperature of the liquid in the sub-boiling chamber (2) to be lower than the boiling point of the liquid, and the heat supply from constant boiling evaporation to sub-boiling evaporation is realized.
2. The sub-boiling distillation apparatus utilizing constant boiling heat supply according to claim 1, wherein the non-contact capacitive liquid level sensor (10) comprises at least two sensors corresponding to a preset upper liquid level threshold value and a preset lower liquid level threshold value respectively, wherein a signal output end of the non-contact capacitive liquid level sensor is connected to a control system, and the control system controls the opening and closing of the feed valve (7) according to the received signal so as to realize automatic liquid supplementing.
3. The sub-boiling distillation apparatus using constant boiling heat supply as claimed in claim 1, wherein an insulation jacket (11) is wrapped on the outer wall of the constant boiling chamber (1) for reducing heat loss and improving heat efficiency.
4. The device for sub-boiling distillation using constant boiling heat supply as claimed in claim 1, wherein the constant boiling chamber (1), the sub-boiling chamber (2) and the constant boiling condenser (3) are all made of high purity quartz glass, and the sub-boiling condenser (8), the liquid collecting bottle (9) and the connecting pipes thereof are all made of soluble polytetrafluoroethylene materials.
5. The sub-boiling distillation apparatus using constant boiling heat supply as claimed in claim 1, wherein the condensate buffer tank (4) is matched with the condensate reflux valve (6) for controlling the pressure in the constant boiling chamber (1) by adjusting condensate reflux quantity, thereby indirectly adjusting the evaporation temperature of the liquid in the sub-boiling chamber (2) according to An Tuo due to equation.
6. The sub-boiling distillation apparatus using constant boiling heat supply as claimed in claim 1, wherein the apparatus has two operation modes, namely, a single sub-boiling distillation purification mode in which the constant boiling chamber (1) provides only a heat source for the sub-boiling chamber (2) when the condensate outlet valve (5) is closed and the condensate reflux valve (6) is opened, and a continuous purification mode in which the first-stage constant boiling distillation and the second-stage sub-boiling distillation are connected in series when the condensate outlet valve (5) is opened.
7. The device for sub-boiling distillation using constant boiling heat supply as claimed in claim 1, wherein a surface area enhancing inner member (13) for forming a liquid column on the surface of the member by using the surface tension of the liquid is placed in the sub-boiling chamber (2) to increase the gas-liquid phase interface and enhance the sub-boiling distillation efficiency.
8. The device according to claim 7, wherein the surface area-enhancing inner member (13) is formed by stacking minimum structural units in a longitudinal direction, the liquid columns formed by stacking in the longitudinal direction are not in contact with each other, and air columns are present, and the minimum structural units are designed with a star-shaped line structure and struts with adjustable thickness.
9. The sub-boiling distillation apparatus using constant boiling heat supply as claimed in claim 7 or 8, wherein the surface area enhancing inner member (13) is adapted to an organic solvent having a surface tension lower than that of water, the organic solvent being selected from one or more of an alcohol compound, an alkane compound, a ketone compound or a benzene compound, wherein the alcohol compound is methanol, ethanol or isopropanol, the alkane compound is cyclohexane, n-hexane or n-heptane, the ketone compound is acetone or butanone, and the benzene compound is benzene, toluene or xylene.
10. The device for sub-boiling distillation using constant boiling heat supply according to claim 1, wherein the connection ports between the sub-boiling chamber (2) and the constant boiling chamber (1) and between the components are all in sealing connection with standard frosted ports.

Description

Sub-boiling distillation device utilizing constant boiling heat supply Technical Field The invention relates to the technical field of distillation and purification, in particular to a sub-boiling distillation device utilizing constant boiling heat supply. Background Distillation is a method of separating and purifying a substance by vaporizing a liquid by heating and collecting the vapor by condensation, and is generally used for purifying a liquid substance. In the common distillation means, the boiling distillation has a very wide application scene because of simple process, large treatment capacity. However, boiling distillation produces a large amount of aerosol particles due to the heating of the liquid to the boiling point temperature, which tend to entrain metal ions and solid particles present in the liquid phase. Therefore, the purifying effect of the boiling distillation is quite limited, the content of metal ions in the reagent obtained by the boiling distillation is not greatly changed, and the requirement of high-purity application is difficult to meet. To obtain higher purity reagents, sub-boiling distillation techniques have evolved. The biggest difference between this technique and boiling distillation is that the liquid temperature is below its boiling point, typically controlled to 10-20 ℃ below the boiling point. Because the vapor pressure at the surface of the liquid still exists below the boiling point, the sub-boiling distillation can continuously generate vapor at the surface of the liquid by controlling the temperature and the pressure, and the internal part of the liquid does not generate severe boiling. Because the sub-boiling distillation is slower than the constant boiling distillation, the control process often depends on a diffusion mass transfer step, which can generally design a larger liquid phase surface area to improve evaporation efficiency. The generation of aerosol particles is greatly reduced due to the avoidance of intense boiling of the liquid, thereby avoiding the entrainment of impurities (such as metal ions, solid particles, etc.) into the vapor, and thus enabling purification in the laboratory to obtain organic reagents containing trace metals. The high-purity organic solvent with strictly controlled impurity content is widely applied to the fields of trace analysis and high-precision experiments in laboratories, such as high-precision analysis, pharmacy, electronic manufacturing and the like, and the preparation of a small amount of high-purity reagent is suitable for using sub-boiling distillation. The prior art patent application with the application number of CN202320524249.7 discloses a quartz sub-boiling distillation device for removing trace metal impurities of chlorosilane materials, which is provided with at least three temperature control devices of temperature sensors for respectively detecting liquid phase temperature, gas phase temperature and condensate liquid temperature. Conventional sub-boiling distillation units typically require precise temperature control to avoid boiling of the liquid, which not only increases the complexity of the unit operation, but also increases the unit cost. The patent application No. CN87201984 discloses an azeotropic sub-boiling dual high-purity water evaporator, which adopts a float valve structure of a communicating vessel principle to control the liquid level of a system, is inconvenient to manufacture and limits the density of a reagent to be purified, adopts a gas port of a glass ball which can slightly move up and down as a condensate reflux valve, so that the temperature and the pressure of azeotropic liquid cannot be accurately controlled, and has the advantages of low efficiency and heat loss due to long heat energy utilization way. Patent application number CN202321965473.6 in the prior art discloses a PFA sub-boiling distillation device, which carries out heat radiation to an evaporation kettle through a heat radiation lamp, so that liquid in the evaporation kettle is in a sub-boiling state, and sub-boiling distillation is carried out. The evaporation efficiency of the device is limited by the liquid phase surface area, which is limited by the internal cross-sectional area of the evaporation kettle, resulting in lower evaporation efficiency. Therefore, the invention provides a sub-boiling distillation device utilizing constant boiling heat supply, which is characterized in that the sub-boiling evaporator is nested in the constant boiling evaporator through an integrated jacket structure, the sub-boiling evaporation temperature is automatically controlled through a temperature gradient of heat transfer by utilizing heat energy generated during boiling of constant boiling liquid as a heat source, and meanwhile, a non-contact capacitor liquid level sensor and a condensate reflux valve are introduced to realize intelligent control, so that the problems of complex structure, low control precision, low heat effi