JPS61234902A - Countercurrent stirring type continuous extraction apparatus - Google Patents

Abstract

PURPOSE:To enable effective extraction not only in a small scale apparatus but also in an industrial scale apparatus by installing a columnar stirring blade of a particular shape to the inside of the main body of the apparatus. CONSTITUTION:For example, a columnar stirring blade 5 having an axially symmetrical cross sectional shape with protruded parts and recessed parts is provided. The ratio of the minimum clearance d1 to the maximum clearance d2 between the stirring blade 5 and the inside wall of the main body is adjusted to 0.003-0.7, and the proportion of the cross sectional area (a) of the stirring blade to the sectional area(A) of the tower is regulated to 0.2-0.7. Further, the ratio of the minimum clearance d1 to the inside dia. of the main body(D) is usually regulated to 0.001-0.15. A columnar stirring blade 5 satisfying these conditions is installed usually over a whole range of an extraction zone from a feeding port 1 of heavy liquid to feeding port 2 of light liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a countercurrent stirring type extraction device. Specifically, the present invention relates to an extraction device having columnar stirring blades inside.

[Conventional technology]

Countercurrent extraction apparatuses having a heavy liquid feed-loak and a light liquid extraction port in the upper part and a light liquid feed-rolet and a heavy liquid extraction port in the lower part, in particular, an Othmer column having an internal stirring blade, etc., are known.

On the other hand, a rotating cylindrical column with a single cylindrical stirring blade was too complicated and not cheap.
If the clearance between the inner wall of the device and the stirring blade is increased, extraction will not be effective.

Processing due to the need to reduce clearancegt
Therefore, it is suitable for small-scale use, but when scaled up, the effect is drastically reduced, making it unsuitable for industrialization.

[Means for solving problems]

The present invention improves the drawbacks of the rotating cylindrical column, and allows extraction to be carried out well even on a large scale as an industrial device.
Moreover, as a result of studies aimed at providing a countercurrent stirring continuous extraction device t with an inexpensive and simple mechanism, it was discovered that one of the objects of the present invention can be achieved by employing columnar stirring blades of a specific shape. It is something.

That is, the gist of the present invention is to perform simultaneous cylindrical extraction in a countercurrent stirring type extraction device having a heavy liquid feeder and a light liquid outlet in the upper part, and a light liquid feeder and a heavy liquid outlet in the lower part. Inside the tower.

(1) The ratio a17'a, between the minimum clearance (a+) and the maximum clearance (d,) between the column inner wall and the stirring blade is 010
03, and.

(It) Stirring blade cross-sectional area (a) with respect to column cross-sectional area (A)
The ratio a/A of J is 0.2 to 0.7.

A countercurrent stirring type continuous extraction device characterized by having columnar stirring blades has an outlet, and a light liquid feeder and a heavy liquid extraction port in the lower part. This is a flow agitation type extraction device, especially one that has columnar agitation blades with a special shape as described below inside the main body.

It is columnar and usually has two or more protrusions, especially three or more.
! Preferably one with one.

Ratio dt/? between the minimum clearance (d,) and the maximum clearance (d,) between the columnar stirring blade and the inner wall of the main body? teeth.

0.003-0.7, preferably 0.007-0.3
Good. The larger this ratio gets, the closer it gets to /.

Closer to the rotating cylindrical column, the extraction throughput decreases.

On the other hand, if this ratio is too small, the mixing state of the liquid in the concave portion of the stirring blade will deteriorate and the extraction efficiency will decrease. Also,! The ratio a/A of the stirring blade cross-sectional area (a) to the cross-sectional area (A) is 0. , Z~θ·71 preferably 0, . 2! ~0.
j! Good. If this ratio tD is too large, the extraction throughput tends to decrease relative to the scale of the extraction tower.
On the other hand, if this ratio is too small, the agitation effect by the agitation blade becomes small and the extraction effect tends to decrease, which is not preferable.

Furthermore, the ratio d between the minimum clearance d1 and the inner diameter of the main body
x/D is 1 usually, θ, O0/~0. /! , preferably 0.002 to θ,/. If this ratio is too large,
The mixing effect of the stirring blade is reduced, making it impossible to obtain a good extraction effect. On the other hand, if this ratio is too small, the power of the rotation motor for stirring will be limited and the rotation motor will be limited.

It is preferable that the columnar stirring blades satisfying these conditions be provided over almost the entire extraction section from the single-heavy liquid feeder to the light liquid feeder, as shown in the figure.

When performing extraction using the apparatus of the present invention.

Usually, heavy liquid feed is used to feed heavy liquid.

On the other hand, while feeding the light liquid through the lower light liquid feeder, and drawing out the extract liquid from the extraction port, the columnar stirring blades
For example, 3θa-koθ00 rpm.

Preferably, the extraction process is performed while stirring at a speed of /000 to /j00 rpm to achieve a predetermined residence time. The rotation speed varies depending on the target processing liquid, but in general,
If the rotation speed is too low.

Since the extraction efficiency tends to decrease and it is impossible to increase the extraction efficiency to an extreme due to limitations on the motor for one rotation, it is selected as appropriate depending on the processing liquid.

[For production]

With the apparatus of the present invention, efficient extraction can be carried out not only as a small-scale apparatus but also as an industrial-scale apparatus.

This is because the shearing force is relatively weak in the minimum clearer area between the stirring blade and the inner wall of the main body, and the liquid is momentarily left still in the seven devices.

It is presumed that this is because it can play the role of mixer and settler.

[Implementation IpH] Example In the extraction apparatus shown in Fig. 1, Fig. 2. The extraction process was carried out using a countercurrent stirring extraction device having stirring blades with a cross-sectional shape of (mouth).

(Device size) Tower High //JO- Tower diameter /4. J-.

Stirring blade dI/dt = 0-j core a / A = + OJ stirring blade length ♂0θ■ Number of revolutions / 000 rpm First, ammonium sulfate aqueous solution (containing 8-2% by mass of ε-caprolactam) was added to the stirrer. At ℃, /θ-/- was fed from a heavy liquid feeder (Fig. 7), while benzene was fed from a light liquid feeder at /1ml/-,
Extraction was carried out continuously with stirring at rpm.

The concentration of ε-caprolactam in the aqueous ammonium sulfate solution after this extraction treatment was measured and found to be 9 ppm.

Comparative example In the example, the cross section of the columnar stirring blade is circular.

(To Clearance) As a result of carrying out the same extraction process as in the example, the amount of ε-caprolactam in the ammonium sulfate aqueous solution after the extraction process was 6/Oppm.

〔Effect of the invention〕

By employing the extraction apparatus of the present invention, extraction can be carried out in a mobile manner even on an industrial scale. Moreover, it is suitable as an industrial device because it is inexpensive and has a simple mechanism.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view of the m- device of the present invention. Figures C (A) to (E) are cross-sectional views of columnar stirring blades that are applicable to Figures 1 and 2.

Claims (1)

[Claims] (1) In a countercurrent stirring type continuous extraction device having a heavy liquid feeder and a light liquid outlet in the upper part and a light liquid feeder and a heavy liquid outlet in the lower part, inside the cylindrical extraction column, (1) Minimum clearance between column inner wall and stirring blade (d_1)
and the maximum clearance (d_2), the ratio d_1/d_2 is 0.003 to 0.7, and (II) the ratio a/A of the stirring blade cross-sectional area (a) to the column cross-sectional area (A) is 0. .2 to 0.7. A countercurrent stirring type continuous extraction device characterized by having columnar stirring blades.