JP4365793B2 - Centrifugal thin film evaporator - Google Patents

Description

  The present invention relates to a thin-film evaporation apparatus, and more specifically, a raw material liquid containing a substance to be evaporated is formed into a liquid film by centrifugal force without using a rotating blade or a rotating brush so that the evaporation can be efficiently performed. The present invention relates to a centrifugal thin film evaporator.

One type of evaporator is a thin-film evaporator that uses a raw material liquid containing the substance to be evaporated in the form of a thin liquid film on the inner surface of the heating tube, and heats the liquid film-like raw material liquid to evaporate the substance to be evaporated. There is.
In general, this thin film evaporator is a type of thin film evaporator without forced stirring, such as a rising thin film evaporator or a descending thin film evaporator, or a rotating blade rotating in a heating tube. For example, there is a forced agitation thin film evaporator that forms and renews a liquid film.

  By the way, in the forced agitation thin film evaporator, heat transfer is performed from the surrounding heat transfer surface to the thin film formed in the narrow gap between the blades and the heat transfer surface. In addition, evaporative concentration can be performed with a short residence time and a narrow concentration space.

However, in the forced stirring thin film evaporator,
(1) The types of liquids that can be handled (liquidity) are limited. For example, they are not suitable for concentrating highly foamable liquids.
(2) Since it has rotating blades, the dynamic balance holding structure, seal structure, bearing structure, etc. are complicated, and there is a problem in that maintenance and management are troublesome and expensive.

  In addition, as an evaporation apparatus capable of efficiently concentrating a highly foamable liquid, a centrifugal thin film vacuum evaporation apparatus that performs an evaporation operation by making a liquid into a thin film using a centrifugal force has been proposed. (See Patent Document 1).

As shown in FIG. 5, the centrifugal thin film vacuum evaporator has a horizontal hollow rotator 53 having a horizontal rotating shaft 52 disposed in an outer shell member 51. In addition, an evaporation surface 54 is formed on the inner peripheral side of the rotator 53, and a tip of a raw material liquid supply pipe 55 having a scattering prevention plate S is disposed near the rotation shaft 52 of the evaporation surface 54. In the vicinity of the outermost peripheral portion of the evaporation surface 54, a pairing tube 56 for discharging the concentrate is disposed.
In this centrifugal thin film vacuum evaporator, desired evaporation is performed while the raw material liquid supplied from the raw material liquid supply pipe 55 moves from the small diameter portion to the large diameter portion of the conical rotator 53.

  And according to this centrifugal thin film vacuum evaporation apparatus, even if a highly foamable raw material liquid is supplied from the raw material liquid supply pipe 55, the foamed raw material is not scattered by the scattering prevention plate S, and the distilled liquid side Since it is possible to prevent the raw material liquid from being mixed, it is said that the highly foamable raw material liquid can be concentrated efficiently.

However, in the case of this centrifugal thin film vacuum evaporator,
(1) It is difficult to ensure a large heat transfer area without causing an increase in the size of the apparatus due to the structure in which a horizontally mounted hollow conical rotating body is used.
(2) Due to the structure of rotating a horizontal-type hollow conical rotating body, there is a problem that the device design is likely to be complicated, and the design cost and manufacturing cost are likely to increase.
Japanese Utility Model Publication No. 6-29601

  The invention of the present application solves the above-described problems, and can efficiently exhibit the characteristics of a centrifugal thin film evaporator without requiring a complicated structure, while suppressing an increase in cost, and a large size. An object of the present invention is to provide a centrifugal thin film evaporator that can be made simple.

In order to solve the above problems, a centrifugal thin film evaporator of the present invention (Claim 1)
The material to be evaporated, which is substantially cylindrical and is configured so that the inner peripheral surface is a heat transfer surface, is disposed so that the axial direction is substantially parallel to the vertical direction, rotates around the axis, and is to be evaporated. A cylindrical rotating body that evaporates the material to be evaporated from the raw material liquid with heat transferred from the inner peripheral surface to the liquid film-like raw material liquid, while the raw material liquid is pressed against the inner peripheral surface by centrifugal force to form a liquid film ,
A rotating means for rotating the cylindrical rotating body;
Heating means for heating the cylindrical rotating body;
A raw material liquid supply line for supplying the raw material liquid into the cylindrical rotating body;
A concentrated liquid extraction line for extracting the concentrated liquid evaporated and concentrated in the cylindrical rotating body from the cylindrical rotating body ;
The inner peripheral surface of the cylindrical rotating body includes a plurality of inner peripheral surface regions having different inner diameters in the axial direction, and the plurality of inner peripheral surface regions having different inner diameters are stepwise upward. It is arranged so that the inner diameter becomes larger,
The liquid film-like raw material liquid pressed against the inner peripheral surface of the cylindrical rotating body by centrifugal force rises and moves from the inner peripheral surface region having a lower inner diameter to the upper inner peripheral surface region by a centrifugal force. While being configured to evaporate and concentrate,
In the cylindrical rotating body configured so that the inner diameter gradually increases upward, the upper end portion of each inner peripheral surface region has a liquid film shape pressed against each inner peripheral surface region by centrifugal force. While holding the raw material liquid in each inner peripheral surface area, a weir is provided for defining the film thickness of the liquid film-like raw material liquid, and
Concentrated liquid that exceeds the weir provided at the upper end of the uppermost inner peripheral surface area is extracted from the concentrated liquid extraction line.
It is characterized by.

The centrifugal thin film evaporator according to claim 2 is the structure of the invention according to claim 1,
The raw material liquid supply line for supplying the raw material liquid into the cylindrical rotating body is configured to be able to supply the raw material liquid near the bottom of the cylindrical rotating body,
The concentrated liquid extraction line for extracting the concentrated liquid evaporated and concentrated in the cylindrical rotating body extracts the concentrated liquid that has been evaporated and concentrated in the inner peripheral surface region having the largest inner diameter above the cylindrical rotating body. It is configured so that it can be used.

Further, the centrifugal thin film evaporator according to claim 3 is the configuration of the invention according to claim 1 or 2 ,
The heating means is a heating steam jacket disposed so as to cover the cylindrical rotating body and rotating together with the cylindrical rotating body, and the cylindrical rotating body is heated by supplying steam therein. And the heating steam jacket has a tapered shape with a diameter decreasing from the lower part toward the upper part,
Drain generated by condensing the steam used to heat the cylindrical rotating body is collected near the bottom of the heating steam jacket by centrifugal force, and from the vicinity of the bottom to the outside through the drain discharge line. It is characterized in that it is configured to be discharged.

According to a fourth aspect of the present invention, there is provided the centrifugal thin film evaporator according to any one of the first to third aspects, wherein the evaporation operation in the cylindrical rotating body is performed under vacuum or under pressure. It is characterized by having.

  The centrifugal thin film evaporator according to the present invention (Claim 1) is configured to have a substantially cylindrical shape and an inner peripheral surface to be a heat transfer surface, and is arranged so that an axial direction is substantially parallel to a vertical direction. The raw material liquid that rotates around and presses the raw material liquid containing the substance to be evaporated, which is a substance to be evaporated, against the inner peripheral surface by centrifugal force to form a liquid film, and by the heat transferred from the inner peripheral surface to the liquid film raw material liquid, A cylindrical rotating body for evaporating the material to be evaporated from the raw material liquid, a rotating means for rotating the cylindrical rotating body, a heating means for heating the cylindrical rotating body, and a raw material liquid supply for supplying the raw material liquid into the cylindrical rotating body Line and a concentrated liquid extraction line for extracting the concentrated liquid evaporated and concentrated in the cylindrical rotating body to the outside from the cylindrical rotating body, so that a short residence time without requiring a complicated structure, Evaporation concentration can be performed with a short heat history.

  In addition, in the centrifugal thin film evaporator of the present invention, the force that presses the liquid against the heat transfer surface by the centrifugal force generated by the rotation of the cylindrical rotating body (the heat transfer surface itself that is substantially vertical cylindrical) , Because it is possible to obtain a force that rises upward while forming a thin film, and evaporation concentration can be performed while pressing the liquid film against the inner peripheral surface (heat transfer surface) of the cylindrical rotating body, It is possible to obtain a sufficient foam suppression effect for the foaming substance. Note that, in the centrifugal thin film evaporator of the present invention, generally, as the rotational speed of the cylindrical rotating body increases, the foam suppression effect on the foaming substance tends to be improved.

In addition, in the centrifugal thin film evaporator of the present invention, since a thin liquid film is formed by centrifugal force, as in the case of mechanically forming a thin film by a rotary blade, a stirring blade, or a scraper, Does not give a large shearing force to the liquid.
Therefore, by using the centrifugal thin film evaporator of the present invention, in a conventional evaporator such as a liquid containing a substance sensitive to thermal history, a liquid containing a substance having a strong foaming property, a liquid containing a substance sensitive to a shearing force, etc. It becomes possible to sufficiently cope with the evaporation and concentration of the liquid that was not easy to cope with.

  In addition, the centrifugal thin film evaporator of the present invention has no rotating blade in the wetted part with the raw material liquid, and there is no gap due to the joining of the members. There is a feature that there is no contamination due to contact or residual liquid.

  Further, since the centrifugal thin film evaporator of the present invention does not require a complicated structure as described above, it is possible to increase the size while suppressing an increase in cost, and the centrifugal thin film type excellent in practicality. An evaporation device can be provided.

Further, the inner peripheral surface of the cylindrical rotating body includes a plurality of inner peripheral surface regions having different inner diameters in the axial direction, and the plurality of inner peripheral surface regions having different inner diameters are directed upward. Since the inner diameter is gradually increased, the liquid film-like raw material liquid pressed against the inner peripheral surface of the cylindrical rotating body by centrifugal force is used to reduce the inner peripheral surface having a smaller inner diameter below by centrifugal force. It is possible to perform evaporation and concentration while moving up and moving from the region to the inner peripheral surface region having a large inner diameter.

  That is, by causing the liquid film-like raw material liquid to evaporate while being lifted and moved from the inner peripheral surface region having a small inner diameter to the upper inner surface region having a large inner diameter by centrifugal force, Evaporation can be performed stepwise in the cylindrical rotating body, and efficient evaporation and concentration can be performed.

In addition, by gradually increasing the inner diameter toward the upper side, it becomes possible to increase the centrifugal force in the inner peripheral surface region having a large upper inner diameter, and the inner peripheral surface region having a large upper inner diameter is foamed. It becomes possible to set it as the area | region where a suppression effect and a defoaming effect are large.
Further, the liquid that is pressed against each inner peripheral surface region by centrifugal force on the upper end portion of the inner peripheral surface region having each inner diameter of the cylindrical rotating body configured so that the inner diameter gradually increases upward. While holding the film-form raw material liquid in each inner peripheral surface region and providing a weir for defining the film thickness of the liquid film-form raw material liquid, the liquid film-form raw material liquid is dammed up to the film It is possible to regulate the thickness, and the concentrated liquid exceeding the weir provided at the upper end of the uppermost inner peripheral surface area is extracted from the concentrated liquid extraction line. It becomes possible to prevent evaporating and to perform efficient evaporation concentration more reliably.

In addition, as in the centrifugal thin film evaporator according to claim 2 , while supplying the raw material liquid from the raw material liquid supply line to the vicinity of the bottom of the cylindrical rotating body, the inner peripheral surface region having the largest inner diameter above the cylindrical rotating body In the case where the concentrated liquid that has been evaporated and concentrated is extracted from the concentrated liquid extraction line, the liquid film-shaped raw material liquid pressed against the inner peripheral surface of the cylindrical rotating body by centrifugal force is The inner peripheral surface region having a small inner diameter and the inner peripheral surface region having a larger inner diameter are made to evaporate and concentrate while being reliably raised, and the concentrated liquid that has been evaporated and concentrated in the inner peripheral surface region having the largest inner diameter is extracted Therefore, it is possible to prevent the raw material liquid from being mixed on the concentrated liquid side and perform efficient evaporation and concentration.

Further, as in the centrifugal thin film evaporator according to claim 3 , a heating steam jacket disposed so as to cover the cylindrical rotating body and rotating together with the cylindrical rotating body is used as the heating means, and the shape of the heating steam jacket By forming a tapered shape with a diameter that decreases from the bottom to the top, the drain that is generated when the steam used to heat the cylindrical rotating body condenses is removed by the centrifugal force around the bottom of the heating steam jacket. It can be collected in the vicinity and discharged efficiently from the drain discharge line.

Further, when the evaporation operation in the cylindrical rotating body can be performed under vacuum as in the centrifugal thin film evaporator of claim 4 , it is possible to perform evaporation and concentration at a low temperature. When a liquid containing a substance sensitive to heat history can be efficiently evaporated and concentrated, and the evaporation operation in a cylindrical rotating body can be performed under pressure, the liquid must be operated at a high temperature. In the case of using a centrifugal thin film evaporator of the present invention in a multi-effect evaporation / concentration system. The invention can be further improved.
When the evaporation operation is performed under pressure, normally, the evaporation operation under pressure can be performed without causing significant complication of the apparatus up to a pressure of about 0.3 MPa.

  The features of the present invention will be described in more detail below with reference to examples of the present invention.

  FIG. 1 is a diagram showing a configuration of a main part of a centrifugal thin film evaporator according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part showing an arrangement mode of a concentrate extraction line, and FIG. FIG. 4 is a diagram showing an arrangement mode of a drain discharge line for discharging the drain collected near the bottom of the heating steam jacket.

  As shown in FIGS. 1 to 4, the centrifugal thin film evaporator according to this embodiment includes a cylindrical rotating body 3 that is substantially cylindrical and has an inner peripheral surface 1 serving as a heat transfer surface, and a cylindrical rotating body. Rotating means 4 for rotating 3, heating means 5 for heating cylindrical rotating body 3, raw material liquid supply line 6 for supplying raw material liquid 2 into cylindrical rotating body 3, and evaporation in cylindrical rotating body 3 A concentrated liquid extraction line 7 is provided for extracting the concentrated liquid 12 from the cylindrical rotating body 3 to the outside.

  The cylindrical rotating body 3 is arranged so that the axial direction (X direction) is substantially parallel to the vertical direction and is configured to rotate about the axis, and the substance to be evaporated, which is a substance to be evaporated, is arranged. The contained raw material liquid 2 is pressed against the inner peripheral surface 1 by centrifugal force to form a liquid film, and the material to be evaporated is evaporated from the raw material liquid 2 by heat transmitted from the inner peripheral surface 1 to the liquid film-like raw material liquid 2. It is configured.

Further, the inner peripheral surface 1 of the cylindrical rotating body 3 includes three inner peripheral surface regions R1, R2, and R3 having different inner diameters in the axial direction, and inner peripheral surface regions R1, R2, and R2 having different inner diameters. R3 is disposed so that the inner diameter gradually increases upward. That is, in the centrifugal thin film evaporator of this embodiment, the liquid film-like raw material liquid 2 pressed against the inner peripheral surface of the cylindrical rotating body 3 by the centrifugal force is converted into an inner peripheral surface having a small inner diameter below by the centrifugal force. The evaporative concentration is performed while moving up and moving from the region R1 to the inner peripheral surface region R3 having the largest inner diameter through the inner peripheral surface region R2.
The rotating means 4 for rotating the cylindrical rotating body 3 can be of any configuration using various known driving means such as an electric motor.

  Further, in the centrifugal thin film evaporator of this embodiment, the raw material liquid 2 is passed through the intermediate inner peripheral surface region R2 from the inner peripheral surface region R1 having a lower inner diameter by centrifugal force, and has the largest upper inner diameter. The raw material liquid 2 is supplied to the vicinity 3a of the bottom of the cylindrical rotating body 3 through the raw material liquid supply line 6 so that the inner peripheral surface region R3 can be evaporated and concentrated while reliably rising. It is configured.

In addition, the inner peripheral surface regions R1, R2, and R3 of the cylindrical rotating body 3 that are disposed so that the inner diameter gradually increases upward are formed on the inner peripheral surface regions by centrifugal force. To define the film thickness of the liquid film-like raw material liquid 2 pressed against R1, R2, and R3, and to hold the raw material liquid 2 in each of the inner peripheral surface regions R1, R2, and R3 while maintaining a predetermined film thickness A weir 8 (8a, 8b, 8c) having a predetermined height (weir height for damming the liquid film-like raw material liquid to regulate the film thickness) H is provided.
In addition, about the relationship between the internal diameter and height t of each inner peripheral surface area | region R1, R2, R3, and the height H of the weir 8 (8a, 8b, 8c) of each inner peripheral surface area | region R1, R2, R3, processing It can be set arbitrarily in consideration of conditions such as the amount of liquid and residence time.

  As shown in FIGS. 2 and 3, the concentrated liquid extraction line is formed in the groove 9 formed at a position beyond the weir 8 (8c) provided at the upper end of the uppermost inner peripheral surface region R3 having the largest inner diameter. 7 is arranged so that the concentrated liquid after evaporative concentration in the uppermost inner peripheral surface region R3 having the largest inner diameter is extracted.

  As described above, the raw material liquid 2 is supplied from the raw material liquid supply line 6 to the bottom vicinity 3a of the cylindrical rotating body 3, and exceeds the weir 8 (8c) provided at the upper end of the uppermost inner peripheral surface region R3. By extracting the concentrated liquid from the position, it is possible to prevent the concentrated liquid and the raw material liquid from being mixed, and to perform efficient evaporation and concentration more reliably.

  As shown in FIG. 4, a heating steam jacket configured to heat the cylindrical rotating body 3 with steam is used as the heating means 5 for heating the cylindrical rotating body 3. The heating steam jacket (heating means) 5 is disposed so as to cover the cylindrical rotator 3, rotates together with the cylindrical rotator, and supplies steam from the steam supply line 13 to the inside of the cylindrical rotator 3. Is configured to be heated. The heating steam jacket 5 has a tapered shape whose diameter decreases from the lower part to the upper part, and the drain that is generated by condensing the steam by heating the cylindrical rotating body 3 is heated by the centrifugal force. The jacket 5 is collected in the vicinity of the bottom periphery 5 a and is discharged to the outside through the drain discharge line 10.

  Further, in the centrifugal thin film evaporator of this embodiment, each constituent member such as the cylindrical rotating body 3 provided with the heating means 5 is accommodated in the vacuum vessel 11 (FIG. 1) and is subjected to a predetermined vacuum (under reduced pressure). ) To perform the evaporation operation.

  The raw material liquid supply line 6 and the concentrated liquid extraction line 7 are introduced into the inside from the upper part of the vacuum vessel 11, and the drain discharge line 10 and the vapor supply line 13 are introduced into the inside from the bottom center of the vacuum vessel 11. ing. Further, the vapor evaporated by the cylindrical rotating body 3 is configured to be discharged from the body 11 a of the vacuum vessel 11 to the outside.

  When evaporating and concentrating using the centrifugal thin film evaporator configured as described above, the raw material liquid is supplied from the raw material liquid supply line 6 to the vicinity 3a of the bottom of the cylindrical rotating body 3 that rotates at a predetermined rotational speed. The force generated by the centrifugal force generated by the rotation of the cylindrical rotating body 3 against the raw material liquid 2 against the inner peripheral surface region (heat transfer surface) R1, and the upper inner peripheral surface region ( Heat transfer surface) A force that rises and moves in order to R2 and R3 is given.

As a result, evaporation and concentration can be performed with a short residence time and a short heat history, and evaporation is performed while the liquid film of the raw material liquid is pressed against the inner peripheral surface area (heat transfer surface) by centrifugal force. It is possible to obtain a sufficient foam suppression effect for the foaming substance.
Therefore, by using the centrifugal thin film evaporator of the present invention, it is possible to efficiently perform evaporation and concentration of a liquid containing a substance sensitive to heat history or a substance having foamability.
Further, since the evaporation operation in the cylindrical rotating body can be performed under vacuum, it is particularly suitable for evaporating and concentrating a liquid containing a substance sensitive to heat history.

  Furthermore, since a liquid film (thin film) is formed by centrifugal force, it does not give a large shearing force to the liquid as in the case of mechanically forming a thin film by rotating blades, etc., and is sensitive to shearing force. The present invention can also be applied without particular problem to the evaporation and concentration of liquids containing various substances.

In the above embodiment, the case where the cylindrical rotating body 3 includes three inner peripheral surface regions R1, R2, and R3 having different inner diameters has been described as an example. In the centrifugal thin film evaporator of the present invention, There is no particular restriction on the number of inner peripheral surface regions having different inner diameters, and in some cases, a configuration including only one inner peripheral surface region is possible, and a configuration including two inner peripheral surface regions. It is also possible to have a configuration including four or more inner peripheral surface regions.
Further, regarding the cylindrical rotating body, the relation between the inner diameter and the height can be arbitrarily set in consideration of conditions such as the amount of processing liquid and the residence time.

  Moreover, in the said Example, although the taper-shaped heating steam jacket whose diameter becomes small toward the upper direction is used as the heating means 5, there are no special restrictions in the specific shape and structure of a heating means, and various Applications and modifications can be added. Further, the heating means 5 is not limited to using steam as a heat source, and an electric heater or the like may be used depending on circumstances.

  Also, regarding the arrangement mode of the raw material liquid supply line for supplying the raw material liquid into the cylindrical rotating body and the concentrated liquid extraction line for extracting the concentrated liquid evaporated and concentrated in the cylindrical rotating body from the cylindrical rotating body, The present invention is not limited to the above embodiment, and various applications and modifications can be added.

  In the above embodiment, the centrifugal thin film evaporator operated under vacuum has been described as an example. However, the present invention can be applied to a centrifugal thin film evaporator operated under normal pressure or under pressure. Is possible.

  The invention of the present application is not limited to the above-described embodiments in other points, and various applications and modifications can be added within the scope of the invention.

  As described above, the centrifugal thin film evaporator according to the present invention is configured such that the raw material liquid is pressed against the inner peripheral surface of the cylindrical rotating body by centrifugal force to form a liquid film, and is transmitted from the inner peripheral surface to the liquid film-shaped raw material liquid. Since evaporative concentration is performed by heat, liquids containing substances sensitive to thermal history, liquids containing highly foamable substances, liquids containing substances sensitive to shearing force, etc. should be compatible with conventional evaporators However, it is possible to sufficiently cope with the evaporation and concentration of the liquid which has not been easy.

  Therefore, the centrifugal thin film evaporation apparatus of the present invention is a material that is vulnerable to mechanical action such as shearing force in fields where concentration of liquids containing foaming substances is required in industrial fields such as fine chemicals, pharmaceuticals, and foods. Fields that require concentration and distillation operations, fields that require contact with foreign substances such as agitating blades as much as possible, fields that require concentration and distillation operations, and substances that want to avoid deterioration due to heat It can be widely applied to various fields.

It is a figure which shows the structure of the principal part of the centrifugal thin film type evaporator concerning one Example of this invention. It is a principal part expanded sectional view which shows the arrangement | positioning aspect of the concentrate extraction line in the centrifugal thin film type evaporator concerning one Example of this invention. It is a principal part enlarged front view which shows the arrangement | positioning aspect of the concentrate extraction line in the centrifugal thin film type evaporator concerning one Example of this invention. It is a figure which shows the arrangement | positioning aspect of the drain discharge line for discharging | emitting the drain collected near the bottom part vicinity of a heating steam jacket in the centrifugal thin film type evaporator concerning one Example of this invention. It is a figure which shows the structure of the conventional centrifugal thin film vacuum evaporation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner peripheral surface 2 Raw material liquid 3 Cylindrical rotary body 3a Near bottom of cylindrical rotary body 4 Rotating means 5 Heating means (heating steam jacket)
5a Near the bottom of the heating steam jacket 6 Raw material liquid supply line 7 Concentrated liquid extraction line 8 (8a, 8b, 8c) Weir 9 Groove 10 Drain discharge line 11 Vacuum vessel 11a Body of vacuum vessel 12 Concentrated liquid 13 Vapor supply line R1 , R2, R3 Inner surface area t Height of inner surface area H Height of weir

Claims (4)

The material to be evaporated, which is substantially cylindrical and is configured so that the inner peripheral surface is a heat transfer surface, is disposed so that the axial direction is substantially parallel to the vertical direction, rotates around the axis, and is to be evaporated. A cylindrical rotating body that evaporates the material to be evaporated from the raw material liquid with heat transferred from the inner peripheral surface to the liquid film-like raw material liquid, while the raw material liquid is pressed against the inner peripheral surface by centrifugal force to form a liquid film ,
A rotating means for rotating the cylindrical rotating body;
Heating means for heating the cylindrical rotating body;
A raw material liquid supply line for supplying the raw material liquid into the cylindrical rotating body;
A concentrated liquid extraction line for extracting the concentrated liquid evaporated and concentrated in the cylindrical rotating body from the cylindrical rotating body ;
The inner peripheral surface of the cylindrical rotating body includes a plurality of inner peripheral surface regions having different inner diameters in the axial direction, and the plurality of inner peripheral surface regions having different inner diameters are stepwise upward. It is arranged so that the inner diameter becomes larger,
The liquid film-like raw material liquid pressed against the inner peripheral surface of the cylindrical rotating body by centrifugal force rises and moves from the inner peripheral surface region having a lower inner diameter to the upper inner peripheral surface region by a centrifugal force. While being configured to evaporate and concentrate,
In the cylindrical rotating body configured so that the inner diameter gradually increases upward, the upper end portion of each inner peripheral surface region has a liquid film shape pressed against each inner peripheral surface region by centrifugal force. While holding the raw material liquid in each inner peripheral surface area, a weir is provided for defining the film thickness of the liquid film-like raw material liquid, and
The centrifugal thin film evaporator is characterized in that the concentrated liquid exceeding a weir provided at the upper end of the uppermost inner peripheral surface area is extracted from the concentrated liquid extraction line . The raw material liquid supply line for supplying the raw material liquid into the cylindrical rotating body is configured to be able to supply the raw material liquid near the bottom of the cylindrical rotating body,
The concentrated liquid extraction line for extracting the concentrated liquid evaporated and concentrated in the cylindrical rotating body extracts the concentrated liquid that has been evaporated and concentrated in the inner peripheral surface region having the largest inner diameter above the cylindrical rotating body. The centrifugal thin film evaporator according to claim 1 , wherein the centrifugal thin film evaporator is configured to be able to perform. The heating means is a heating steam jacket disposed so as to cover the cylindrical rotating body and rotating together with the cylindrical rotating body, and the cylindrical rotating body is heated by supplying steam therein. And the heating steam jacket has a tapered shape with a diameter decreasing from the lower part toward the upper part,
Drain generated by condensing the steam used to heat the cylindrical rotating body is collected near the bottom of the heating steam jacket by centrifugal force, and from the vicinity of the bottom to the outside through the drain discharge line. centrifugal thin-film evaporation apparatus according to claim 1 or 2, wherein it is configured so as to be discharged. The centrifugal thin film evaporator according to any one of claims 1 to 3 , wherein the evaporation operation in the cylindrical rotating body is performed under vacuum or under pressure.

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