JPH0415001B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distillation apparatus, and more particularly to an apparatus for distilling substances with high specific gravity, such as liquid metals such as zinc and magnesium.

Pyrometallurgical methods such as the New Jersey method are known as methods for refining non-ferrous metals, such as zinc.
This is a method of fractionating Zn by evaporating and condensing Zn from Zn. The crude Zn refined by the New Jersey method has a relatively high Zn purity of 95-99%, but
When refining a metal mixture with a relatively low Zn purity of several tens of percent, it is necessary to perform so-called multi-stage distillation in which evaporation and condensation are repeated in order to obtain high-purity metals. Because the metal mixture has a high specific gravity and the vapor pressure of the metal is low, it is impossible to use the multi-stage distillation apparatus conventionally used in chemical fields such as petroleum refining. Therefore, when obtaining high-purity metals such as Zn by distillation, it is conceivable to repeatedly perform so-called single-stage distillation in which the condensed liquid metal is fed into the distillation apparatus again after being evaporated for one day. This method is inefficient and requires a large distillation device to obtain the necessary amount of high-purity metal, and metal vapor that has not reached a sufficient level of purity must be cooled and condensed outside the device. Therefore, condensation heat is wasted and there is a problem of poor thermal efficiency.

This invention was made in view of the above circumstances, and an object of the present invention is to provide a compact distillation apparatus that can perform multistage distillation of a liquid phase mixture having a high specific gravity such as a liquid metal with high efficiency and thermal efficiency. It is. A feature of the present invention is that the heating device is operated by a plurality of intermediate shelves provided at intervals in the vertical direction and a plurality of partition plates whose lower ends are immersed in the condensate on the intermediate shelves. The inside of the container is divided into a plurality of evaporation chambers, and the inside of the container is depressurized. A steam cooler is installed in which heat is exchanged between the raw liquid introduced from the outside and the steam inside the container, and the condensed liquid liquefied on the surface of the container is transferred to an intermediate shelf. The main feature is that a conduit is disposed below each partition plate so as to guide the liquid solution heated in the steam cooler to the bottom of the container.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the present invention, in which a container 1 is configured to be sealed with a lid 3 filled with a heat insulating material 2, and the outer periphery of the container 1 and the lid 3 are connected to each other. A heating device 4 consisting of an electric heater or the like for heating the inside of the container 1 is provided. A plurality (two in the figure) of intermediate shelves 6a, 6b for storing the condensate 5 are attached to the inner surface of the container 1 at a predetermined interval in the vertical direction, and these intermediate shelves 6a, A plurality of (two in the figure) partition plates 7a and 7b are attached to the inner surface of the container 1 in correspondence with the partition plates 6b. These partition plates 7a, 7b are the first
As shown in the figure, it is tilted downward toward the corresponding intermediate shelves 6a, 6b, and the lower end portion is located on the intermediate shelves 6a, 6b.
The interior of the vessel 1 is therefore immersed in the upper condensate 5 and the interior of the vessel 1 is immersed in the intermediate shelves 6a, 6b and the condensate 5.
Also, a plurality of (three in the figure) evaporation chambers 8a, 8b, which are liquid-sealed to each other by partition plates 7a, 7b,
It is divided into 8c.

A condenser 10 is connected to the upper part of the upper evaporation chamber 8a via a steam passage 9, and a vacuum pump 11 for reducing the pressure in the upper evaporation chamber 8a is connected to the condenser 10 via a valve 12. has been done. Further, at the lower part of the condenser 10, a distillate outlet 13 is provided for taking out the condensed and liquefied high-purity liquid phase substance (for example, high-purity liquid metal), and further for returning the reflux liquid to the upper evaporation chamber 8a. A liquid pipe 14 is provided between the condenser 10 and the intermediate shelf 6a.

Also, the middle evaporation chamber 8b and the lower evaporation chamber 8c
Inside each partition plate 7a, 7b, parallel to each partition plate 7a, 7b, that is, intermediate shelves 6a, 6
The steam cooler 15a is tilted downward toward b.
15b is arranged. The steam cooler 15
a and 15b are for heating and raising the temperature of the stock solution and cooling and condensing the vapor by transferring heat between the stock solution to be distilled introduced from the outside and the steam in the evaporation chambers 8b and 8c. As shown in FIG. 2, the interior of each steam cooler 15a, 15b has a structure in which the undiluted solution flows in a meandering manner, and the undiluted solution inlets 16a, 16b penetrate the peripheral wall of the container 1 and protrude to the outside. , and the stock solution outlet 17a, 1
7b is connected with conduits 18a and 18b for guiding the stock solution to the bottom of the container 1, that is, to the bottom of the lower evaporation chamber 8c.

Furthermore, condensate receivers 19a, 19b are provided below each steam cooler 15a, 15b to guide the condensate that is condensed and liquefied on the surface of the steam cooler 15a, 15b and drips to the intermediate shelves 6a, 6b. .

A vacuum pump 20 for reducing the pressure inside the middle and lower evaporation chambers 8b and 8c is connected via valves 21 and 22. Further, a residual liquid outlet 23 is formed in the lower part of the lower evaporation chamber 8c.

Next, the operation of the distillation apparatus configured as described above will be explained using an example in which a high purity metal is obtained from a liquid metal mixture.

First, the inside of the container 1, that is, each evaporation chamber 8a, 8
b, 8c are depressurized by the vacuum pumps 11, 20, and the inside thereof is heated to a temperature higher than the evaporation temperature of the target metal by the heating device 4, and the stock solution preheated to a temperature lower than the evaporation temperature is transferred to the steam cooler 15a. , 15b
Let it flow inside. Therefore, each evaporation chamber 8a, 8
In the chambers b and 8c, the target metal in the raw solution or condensate 5 evaporates, and among these, the lower evaporation chamber 8
In c, when the metal vapor comes into contact with the steam cooler 15b, heat is taken away by the raw liquid inside the metal vapor and is condensed and liquefied, and the condensate 5 flows through the steam cooler 15b or drops into the condensate receiver 19b. After that, the condensate is collected on the lower intermediate shelf 6b by the condensate receiver 19b. On the other hand, the raw liquid in the steam cooler 15b increases in temperature by removing sensible heat and latent heat from the steam, and then passes through the conduit 18b to the lower evaporation chamber 8c.
flows down to.

Therefore, although the target metal concentration in the condensate 5 in the middle evaporation chamber 8b has increased to some extent, this liquid metal is heated and evaporated again, and the vapor is transferred to the lower evaporation chamber. 8c, the raw liquid in the steam cooler 15a is given sensible heat and latent heat to be condensed and liquefied, and the condensate 5 is transferred to the steam cooler 15a and the condensate receiver 19.
a and accumulates on the upper intermediate shelf 6a. Further, the raw liquid introduced into the steam cooler 15a increases in temperature by removing sensible heat and latent heat from the steam, and then flows down to the lower evaporation chamber 8c via the conduit 18a.

Since the condensate 5 in the upper evaporation chamber 8a is obtained by evaporating and condensing twice as described above, the concentration of the target metal is even higher. The liquid metal evaporates again, and the vapor reaches the condenser 10 through the vapor passage 9, where it is cooled and becomes the desired high-purity liquid metal. The finally obtained fraction is the fraction outlet 13
The reflux liquid is returned to the upper evaporation chamber 8a via the reflux liquid piping 14.

Therefore, in the above device, each evaporation chamber 8a, 8
Since evaporation and condensation are carried out in b, 8c and the condenser 10, so-called multi-stage distillation is carried out, and as a result, highly pure liquid metal can be obtained efficiently. In addition, in the above-mentioned apparatus, the sensible heat and latent heat of the steam are given to the stock solution to be distilled to recover the heat, so the thermal efficiency can be extremely high.
Moreover, since such heat transfer is performed within the container 1, a compact device can be achieved.

The amount of liquid on each intermediate shelf 6a, 6b gradually increases as the distillation continues, and finally the condensate 5 overflows from the intermediate shelves 6a, 6b and reaches the bottom of the container 1. Also, the concentration of impurities in the liquid at the bottom of the container 1 gradually increases,
The liquid is appropriately extracted from the residual liquid outlet 23.

Here, the results of experiments conducted by the inventors using the above-mentioned apparatus will be shown.

10wt%Mg− under the conditions of evaporation chamber temperature 900℃, condenser temperature 700%, stock solution temperature 650℃, and reflux rate 15%.
When 90wt% Pb solution was vacuum distilled, the purity was 99.5.
We were able to obtain high purity Mg with a purity of more than %.

In addition, although the above-mentioned embodiment was explained by taking the case of refining metal as an example, the distillation apparatus of the present invention can be used not only for metal but also for refining chemical substances such as petroleum. Furthermore, the distillation apparatus of the present invention is not limited to the configuration for performing three-stage distillation as shown in the above-mentioned embodiments, but may be configured to perform three or more stages of distillation by increasing the number of intermediate shelves and partition plates. Of course.

As is clear from the above description, according to the distillation apparatus of the present invention, the interior of the container, which has a heating device and whose interior is depressurized, has a plurality of intermediate shelves vertically spaced apart from each other, The condensate obtained by evaporating in the lower evaporation chamber and then condensing is divided into a plurality of evaporation chambers that are mutually sealed by a plurality of partition plates immersed in the condensate on the shelf. Since the condensate is introduced into the evaporation chamber and then evaporated and condensed again in the upper evaporation chamber, even substances with high specific gravity and low vapor pressure such as gaseous metals can be efficiently subjected to multi-stage distillation. High purity purification can be achieved. In addition, each evaporation chamber is equipped with a steam cooler that transfers heat between the raw liquid to be distilled and the steam, and is configured to give the heat of the steam to the raw liquid, thereby recovering sensible heat and latent heat when the steam condenses. Therefore, thermal efficiency can be improved, and in combination with the structure in which such heat exchange is performed within the container, the apparatus can be made compact as a whole.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional plan view showing a steam cooler thereof. 1... Container, 4... Heating device, 5... Condensate,
6a, 6b...middle shelf, 7a, 7b...partition plate,
8a, 8b, 8c...evaporation chamber, 10...condenser,
11, 20... Vacuum pump, 15a, 15b...
steam cooler. 18a, 18b... conduit, 19a,
19b... Condensate receiver.

Claims (1)

[Scope of Claims] 1. A plurality of intermediate shelves for liquid storage are attached to the inner surface of a container having a heating device and whose interior is depressurized at intervals from each other in the vertical direction, and the lower end is attached to the intermediate shelf. A plurality of partition plates immersed in the condensate above are attached to the inner surface of the container, and a plurality of evaporation chambers sealed by the condensate on the intermediate shelf and the partition plates are defined within the container. The uppermost evaporation chamber is connected to the condenser, and the other evaporation chambers are equipped with vapor coolers that flow the stock solution to be distilled introduced from the outside and cool and condense the vapor in the evaporation chamber. A conduit is disposed below each partition plate to allow the liquid to flow down to the intermediate shelf, and is further provided with a conduit connected to the steam cooler to guide the stock liquid heated in the steam cooler to the bottom of the container. A distillation device characterized by: 2. The distillation apparatus according to claim 1, wherein a condensate receiver for guiding the condensate dripping from the steam cooler onto each of the intermediate shelves is disposed below each steam cooler.