JPH0759281B2 - Thin film evaporator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is purified by evaporating and removing volatile components such as residual monomers and solvents from a high-viscosity liquid material such as a polymer resin produced by a polymerization reaction. The present invention relates to improvement of a thin film evaporation device used for the purpose of obtaining an evaporation treatment liquid.

[Conventional technology]

FIG. 3 shows an example of a prior art forced agitation thin film evaporator.

This device is configured such that the inner peripheral surface (2) of a circular closed container body (1) around the central longitudinal axis (X) is connected to the outer jacket (3) through the heat medium nozzles (4) and (5). A vaporization source (not shown) through a vapor outlet nozzle (6) for volatile component vapor through an external condenser through a vaporization nozzle as a heating evaporation surface.
By connecting to, it is possible to reduce the pressure and vacuum inside the container,
The rotary shaft (7) is rotatably supported by the upper sealed bearing (8) and the lower internal bearing (9) penetrating the upper part of the container main body on the central vertical axis (X) to support the motor (not shown) on the external upper part. No.), the liquid material supplied from the liquid material inlet nozzle (11) to the inside of the container by the dispersion unit (10) mounted above the rotary shaft (7) inside the container Disperse liquid material that is dispersed around the entire circumference and then descends by the stirring blade (13) of the thin film formation unit (12) installed in the lower part to spread it in a thin film on the heating evaporation surface to promote evaporation of volatile components. The vapor is discharged from the vapor outlet nozzle (6), while the vaporized treatment liquid that has completed evaporation is discharged from the treatment liquid outlet (14) at the bottom of the container body by a discharge means such as a gear pump (15). ing. Reference numeral (16) is a support for supporting the lower inner bearing (9) from the inner wall of the inner vessel and traverses the inner side of the vessel.

Generally, in this type of thin-film evaporator, the static liquid pressure is reduced by thinning the film in a depressurized atmosphere to cause evaporation, so the evaporation temperature can be lowered, the thermal effect on the liquid material is reduced, and the thin film is agitated. Since the scraping and downward transfer is performed by the stirring blade as the film becomes thin, it has the feature that it can handle liquid materials with high viscosity.

[Problems to be Solved by the Invention]

However. In the conventional thin film evaporator, the following various problems are prominent as the liquid material becomes highly viscous.

That is, since the lower vessel bearing (9) is supported on the vessel inner wall by the support (16) that traverses the vessel in the radial direction, the high viscosity evaporative treatment liquid that descends along the vessel inner wall surface is supported. If the deposit adheres to and is brought into contact with the stirring blade (13), it causes mechanical unbalance of the rotary system, and continuous operation becomes impossible.

Further, if the deposits, which are qualitatively changed due to the heat effect during the deposition and deposition, come off and enter the evaporative treatment liquid, the quality of the product is deteriorated.

Furthermore, the evaporation treatment liquid moves downward to the treatment liquid outlet (14) by gravity flow due to the thinning unit (12), but when the viscosity becomes high, it becomes difficult to move under the natural flow, and the lower part inside the container body. The evaporative treatment liquid stays in the space, and the residence time in the vessel becomes long, which causes a qualitative change.

An object of the present invention is to provide a comprehensive solution to these problems associated with an increase in viscosity of a liquid material handled in a thin film evaporator.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention provides that the lower rotation shaft can be separately driven from the lower rotation shaft of the upper dispersion unit and the thin film unit, and can be driven separately from the lower rotation shaft. It is possible to maintain a balance in the take-up and connection operation with the withdrawal speed of. Then, the lower bearing of the upper rotary shaft is provided in the lower rotary shaft in a built-in state so as to avoid contact with the high-viscosity liquid and eliminate the internal support of the lower bearing to solve the problem of adhesion and deposition.

In particular, the feature of the present invention is to fundamentally change the structure of the lower part where the problem of handling a high-viscosity liquid of a thin film evaporator is concentrated, and, following the thinning unit, the center of the lower part of the main body of the container which has been reduced in diameter to an inverted cone shape. An agitating auxiliary blade that rotates around the vertical axis is provided, and a discharge mechanism that consists of a screw blade that rotates around the central vertical axis is provided in the downward extension cylindrical portion of the container body, and evaporation processing is performed at the lower inside of the container body. Allow the liquid to be actively withdrawn.

In summary, the thin film evaporation apparatus of the present invention has a structure in which the inner peripheral surface of a circular depressurizable hermetic container body around the central vertical axis is the heating and evaporating surface, and the upper part on the central vertical axis. A rotating shaft and a lower rotating shaft that is separately driven to rotate are provided below the rotating shaft, and the lower bearing of the upper rotating shaft serves as a built-in bearing in the lower rotating shaft. The liquid unit containing the volatile components supplied from the liquid material inlet nozzle into the vessel by the dispersion unit is primarily dispersed over the entire circumference of the inner peripheral surface, and then a thin film is formed on the upper rotary shaft below the dispersion unit. The dispersion material descending by the stirring blade of the unit was spread in a thin film on the heating evaporation surface to promote the evaporation of volatile components, and the evaporation processing liquid was taken out from the processing liquid outlet at the bottom of the container body. Forced thin film evaporation Subsequent to the unit, a scraping auxiliary blade is provided on the upper rotating shaft located at the lower part of the container body that has been reduced in diameter to an inverted cone shape, and the lower part of the container body is extended downward so that it is directly connected to the processing solution outlet. A feature is that a screw blade discharging mechanism is provided on the shaft.

[Work]

In the thin film evaporation apparatus of the present invention, the evaporation treatment liquid that is spread in a thin film by the stirring blades of the thinning unit and is forcedly transferred downwards stays after reaching the lower end of the thinning unit even if it has high viscosity. Immediately without any time, the blades are immediately bitten by the agitating auxiliary blades and the rotating screw blades, transferred downward, and taken out of the device.

The liquid material and the evaporation treatment liquid are forcibly transferred by the agitating blades, agitating auxiliary blades and screw blades of the thinning unit throughout the entire process, and there is no part dependent on gravity free flow between them, so both axes are independent. Since it is possible to transfer in a fixed amount by driving, even when handling a high viscosity liquid, the quality of the evaporation treatment liquid is stable because there is no temporary retention of the evaporation treatment liquid and mixing of qualitative changes does not occur. And good quality is obtained.

In addition, by installing the lower bearing of the upper rotary shaft inside the lower bearing of the screw blade, the internal bearing support of the prior art is not required, and the cause of adhesion and deposition of the evaporative treatment liquid is eliminated. Contributes to maintaining good quality of liquid.

〔Example〕

Hereinafter, the thin film evaporation apparatus of the present invention will be described in more detail with reference to the embodiments of FIGS. 1 and 2. First
FIG. 1 is a vertical sectional side view of the entire apparatus of the embodiment, and FIG. 2 is an enlarged vertical sectional side view of a portion around a lower rotary shaft of a main portion thereof.

The basic configuration of this device as a forced thinning evaporator is the third
Since it is almost the same as the prior art in the figure, the same parts are designated by the same reference numerals, the description thereof is cited, and a peculiar part of the present invention and its relation will be supplementarily explained.

In the device of this embodiment, the inner peripheral surface (2) of the closed container body (1) is cylindrical around the central longitudinal axis (X) and the lower part is reduced to an inverted conical shape, and the outer jacket ( By passing the heat medium through the heat medium nozzles (4) and (5) to 3), it becomes a heating evaporation surface and a heat retaining surface over almost the entire height. The inside of the vessel can be depressurized and evacuated by connecting the vapor outlet nozzle (6) of the volatile component at the top through a condenser outside the vessel to a vacuum source (not shown).

According to the present invention, the upper rotary shaft (7A) has a central longitudinal axis (X) in the container by means of a sealed bearing (8) at the top wall penetrating portion of the upper part and a lower built-in bearing (9A) described later (see FIG. 2). It is supported on the upper part and is driven to rotate by a motor (not shown) on the outside of the device. On the upper rotary shaft (7A), the dispersion unit (10) is located in the upper part of the device, and in the lower part of it. Stirrer (13)
The thinning unit (12) having the above is attached, and further, a lowering assisting blade (17), which will be described later, is attached to the lower part of the cone lower part of the container body.

The liquid material containing a volatile component supplied from the material inlet nozzle (11) into the container is dispersed and lowered by the rotating dispersion unit (10) along the entire inner surface of the container, and then the thin film forming unit (12). (3) is swirled by the stirring blade (13), which is spread in a thin film on the heating and evaporating surface to promote the evaporation of the volatile component, and the thin film is scraped and transferred downward. The vapor of the volatile components thus generated is extracted from the vapor outlet nozzle (6) to the outside of the device, and the evaporated treatment liquid is finally extracted from the treatment liquid outlet (14A) to be described later. Become.

According to the present invention, a sleeve-shaped lower rotary shaft (18), which is connected to the lower part of the container under the upper rotary shaft (7A) but is driven separately, is provided on the central vertical axis (X). A discharge mechanism composed of a screw blade (19) is mounted on the lower rotary shaft (18) from immediately below the aiding assist blade (17) to the inside of the downward extension cylinder (1a) of the container body.

This lower rotary shaft (18) is supported and driven by connecting a vertical axis motor (20) through a seat plate (21) to the lower end of the container main body lower extension cylinder part (1a) as shown in FIG. The hollow reduced diameter lower part of the lower rotary shaft (18) is integrally connected to the upper part of the upwardly projecting output shaft (22) by the bolt (23), and thus the lower rotary shaft (18) is connected by the bearing of the motor (20). Firmly support the rotation on the central vertical axis (X). Then, a stuffing box (24) is provided on the outer periphery of the output shaft (22) to seal the inside of the container, and the processing liquid outlet (14A) is guided laterally from the lower end of the container body lower extension cylinder (1a).

The lower bearing of the upper rotary shaft (7A) has a needle roller bearing bearing (9A) built in the hollow of the lower rotary shaft (18), and the lower extension of the upper rotary shaft (7A) inserted in the hollow ( Since it supports 7a), it is firmly supported and the prior art support (16) is unnecessary. An oil seal (25) is provided around the lower extension (7a) at the upper end of the lower rotary shaft (18) to seal the internal bearing (9A) toward the inside of the device.

With the above configuration, the evaporation treatment liquid from which the volatile components have been removed by evaporation is treated by the stirring blade (1) of the thinning unit (12).
After reaching the lower end of the cylindrical part of the container body (1) corresponding to the lower end of 3), it is fed downward by the assisting blade (17) for immediate downward action and is immediately bitten by the screw blade discharge mechanism (19) to push it out. It is withdrawn from the processing liquid outlet (14A) that is directly connected to it. That is, the liquid material supplied from the material inlet nozzle (11) is dispersed into the dispersion unit (10), the stirring blade (13) of the thinning unit (12), the assisting blade (17), and the screw blade (19) of the discharge mechanism. Therefore, since the liquid is always subjected to the downward liquid feeding action, the residence time of the substance to be treated in the container can be appropriately controlled.

In addition, by incorporating the lower bearing (9A) of the upper rotary shaft (7A) in the lower rotary shaft (18), the support (16), which was the cause of deposition and deposition of the evaporative treatment liquid in the prior art, does not exist, Deterioration of the quality of the evaporation treatment liquid due to the adhered deposit is eliminated. In addition, since the rotation speed of both rotary shafts can be controlled individually, the stirring blade (13) tip peripheral speed and screw blade (19)
The relationship between the two can be arbitrarily set so as to optimize the relationship with the emission amount.

〔The invention's effect〕

As described above, according to the thin film evaporation device of the present invention, the following various effects can be achieved collectively.

(I) Since the spontaneous flow-down portion of the evaporative treatment liquid is eliminated, the residence time of the evaporative treatment liquid in the container can be arbitrarily controlled.

(II) The continuous operation of the device becomes possible by eliminating the deposits deposited in the device.

(III) Since the evaporation treatment liquid does not adhere to the lower bearing support, deterioration of the quality can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an entire thin film evaporation apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional side view of a portion around a lower rotation axis of a main portion thereof, and FIG. It is a vertical side view of an evaporator. (1) …… Container body, (1a) …… Downward extension cylinder, (3)
…… Jacket, (4) (5) …… Heat medium nozzle, (6)
...... Steam outlet nozzle, (7) …… Rotary shaft, (7A) …… Upper rotary shaft, (7a) …… Downward extension, (8) …… Upper sealed bearing, (9) …… Internal bearing , (9A) …… Built-in bearing,
(10) …… Dispersion unit, (11) …… Material inlet nozzle,
(12) …… Thin film unit, (13) …… Stirrer, (14)
(14A) …… Treatment liquid outlet, (15) …… Gear pump,
(16) …… Support, (17) …… Sucking aileron, (18)…
… Lower rotating shaft, (19)… Screw vane discharging mechanism, (2
0) …… Vertical motor, (21) …… Seat plate, (22) …… Output shaft, (23) …… Bolt, (24) …… Stuffing box, (25) …… Oil seal.

Claims (1)

[Claims] 1. An inner peripheral surface of a circular depressurizable hermetic container body around a central vertical axis as a heating and evaporating surface, and an upper rotary shaft on the central vertical axis and a lower part which is separately driven and rotated below the rotary shaft. A rotary shaft is provided, the lower bearing of the upper rotary shaft is used as a built-in bearing in the lower rotary shaft, and it is supplied from the liquid material inlet nozzle into the container by the upper dispersion unit that is mounted and rotates on the upper rotary shaft on the central vertical axis. The liquid material containing volatile components is primarily dispersed all around the inner surface, and then the dispersion material descending by the stirring blade of the thinning unit on the upper rotary shaft below the dispersion unit is heated to the evaporation surface. In the forced thinning evaporation device that was developed in a thin film on the top to promote the evaporation of volatile components, and the evaporation processing liquid was drawn out from the processing liquid outlet at the bottom of the container body, following the thinning unit, An inverted cone-shaped container book A lower blade is provided on the upper rotary shaft at the lower part of the body, and a screw blade discharge mechanism is provided on the lower rotary shaft in the lower extension cylinder of the container body so as to be directly connected to the processing liquid outlet. Thin film evaporator.