JPH0454481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thin film falling type evaporator.

Conventional technology As a thin film falling type evaporator, for example,
There is a falling film type evaporator disclosed in Japanese Patent No. 30562. This falling film type evaporator is the seventh
As shown in the figure, there is a cylindrical shell 1, a plurality of hollow plate-shaped heating elements 2 provided inside the shell 1, and a heating element 2 provided above the heating element 2 and covered on the outer surface of the heating element 2. It consists of a distributor 3 that supplies heating liquid, and a circulation pump 5 that circulates the fluid to be heated accumulated at the bottom of the shell 1 to the distributor 3 via a circulation pipe 4. Further, an evaporative vapor outlet 6 is provided at the upper end of the shell 1 for guiding the evaporative vapor generated from the outer surface of the heating element 2 to the outside of the shell 1, and an evaporative vapor outlet 6 is provided on the upper outer circumferential surface of the shell 1 for discharging the evaporative vapor generated from the outer surface of the heating element 2 to the outside of the shell 1. A heating steam inlet 7 for supplying heating steam into the hollow part of the heating element 2 provided at A heated fluid supply port 8 is provided respectively. Further, at the lower end of the heating element 2, there is a condensate outlet 9 for collecting the heating steam that has passed through the hollow part of the heating element 2 and discharging it to the outside of the shell 1.
A condensate header 10 having a diameter is installed.

When heating steam is introduced into the hollow part of the heating element 2 from the heating steam inlet 7 of the falling film type evaporator having the above configuration, and at the same time, the fluid to be heated is supplied from the fluid to be heated supply port 8 to the bottom of the shell 1. ,
After the heating steam passes through the hollow part of the heating element 2, it is collected in the condensate header 10, and the condensate outlet 9 communicates with the condensate header 10.
is discharged to the outside of shell 1. On the other hand, the fluid to be heated introduced into the bottom of shell 1 is
It passes through a circulation pipe 4 from the bottom and is supplied to the distributor 3 by a circulation pump 5. Here, the fluid to be heated is distributed and supplied onto the outer surface of the heating element 2, flows down the outer surface, and at this time exchanges heat with the heating steam flowing inside the hollow part of the heating element 2. Then, a part of the heated fluid on the outer surface of the heating element 2 evaporates, and the evaporated vapor flows out to both sides of the heating element, and the evaporated vapor exit 6 provided at the upper end of the shell 1
from there to the next stage of equipment. Further, the fluid to be heated that has not evaporated from the outer surface of the heating element 2 falls from the lower end of the heating element 2 to the bottom of the shell 1, and flows back into the circulation pipe 4 together with the fluid to be heated that has been introduced into the bottom of the shell 1. is supplied to the distributor 3 by the circulation pump 5.

Problems to be Solved by the Invention The above type of falling film type evaporator is required to have a long heat transfer length, but since the heating element 2 of this falling film type evaporator has a smooth outer surface, the heat transfer length is If the heating element 2 is made longer, the total length of the heating element 2 will inevitably become longer, resulting in a problem that the overall length of the entire device in the height direction will become longer. Further, when the surface of the heating element 2 is made smooth, there is a problem that when the fluid to be heated flows down the outer surface of the heating element 2, liquid drift occurs in the horizontal direction, and the heat exchange efficiency decreases.

Means for Solving the Problems A thin film falling type evaporator is constructed of a heating element having a cylindrical shape and having inclined grooves on the inner and outer peripheral surfaces, and a shell that houses the heating element. , heat exchange is performed by supplying two types of fluids to the outer peripheral surface and inner peripheral surface of the heating element housed in the shell, respectively.

Effect By forming the heating element in a cylindrical shape and providing inclined grooves on the inner and outer peripheral surfaces, the heat transfer length can be increased without increasing the overall length of the heating element.

Embodiment FIG. 1 is a drawing showing a first embodiment of a thin film falling type evaporator according to the present invention.
A heating element (B) having a cylindrical shape and having an inclined groove (A) having a predetermined angle of inclination on its inner and outer peripheral surfaces, which is closed by (B), and both ends of which the heating element (B) is housed are closed. It is composed of a cylindrical shell 21. At the upper end of the shell 21,
An evaporative vapor outlet 22 for guiding evaporative vapor generated from the outer circumferential surface of the heating element B to the outside of the shell 21.
A concentrated liquid discharge pipe 23 is connected to the lower end of the shell 21 for discharging the concentrated liquid concentrated on the outer peripheral surface of the heating element 21 to the outside of the shell 21. In addition, there is a shell 2 on the upper circumferential surface of heating element B.
A heating steam introduction tube 24 for supplying heating steam to the inside of heating element B is connected to it, and a heating steam introduction tube 24 for supplying heating steam to the inside of heating element B is connected to the lower peripheral surface of heating element B. A discharge pipe 25 for discharging the steam to the outside of the shell 21 is connected thereto. Further, above the heating element RO, there is a heated fluid supply cylinder 2 for supplying the heated fluid to the outer peripheral surface of the heating element RO.
The tip of No. 6 is open.

FIGS. 3 to 6 are drawings for explaining a method of manufacturing a heating element B used in the above-mentioned thin film falling type evaporator. As shown in FIG. 3, this heating element B is made by forming an inclined groove A' on the surface of a flat plate R' by press working or roll processing, and then forming a flat plate R' having the inclined groove A' as shown in FIG. Either it is processed into a cylindrical shape as shown in Figure 5, or straight grooves extending in the longitudinal direction are formed on the surface of a long strip plate R' by press working or roll working, as shown in Figure 5. By winding this strip plate B'' having a straight groove A'' into a spiral shape as shown in Fig. 6 and cutting off both ends C and C, it is processed into a cylindrical shape having an inclined groove A on the circumferential surface. . In addition, when the strip plate R'' is wound into a cylinder in a spiral shape, both ends C and C of the strip plate R'' are kept flat as shown in Fig. 5, and when cutting the part, It may be possible to make the cutting easier.

In the thin film falling type evaporator having the above configuration, heating steam is introduced into the heating element B from the heated steam introduction tube 24, and at the same time, the heated element is introduced from the heated fluid supply tube 26 onto the outer peripheral surface of the heating element B. When supplied, the heating steam passes through the inside of the heating element RO, and then is discharged to the outside through the discharge tube 25 connected to the lower part of the heating element RO. On the other hand, the heated fluid supplied from the heated fluid supply tube 26 to the upper end of the outer circumferential surface of heating element B is applied onto the outer circumferential surface of heating element B along the inclined groove A provided on the outer circumferential surface of heating element B. It flows down while circling. At this time, heat exchange is performed with the heating steam flowing inside the heating element B, a part of the fluid to be heated is evaporated, and the evaporated steam is passed from the evaporative steam outlet 22 provided at the upper end of the shell 21. Sent to the next stage device. Further, the fluid to be heated that has not evaporated from the outer peripheral surface of heating element RO falls from the lower end of heating element RO to the bottom of shell 21 and is led out through the concentrated liquid discharge pipe 23 connected to the bottom of shell 21. be done.

FIG. 2 shows the second thin film falling type evaporator according to the present invention.
The thin film falling type evaporator shown in this figure has a cylindrical shape with both ends open, and has a predetermined slope on its inner and outer peripheral surfaces as in the first embodiment. It is composed of a heating element (b) provided with an inclined groove (a) having an angle, and a cylindrical shell (30) with both ends closed, which accommodates the heating element (b). An evaporative vapor outlet 31 is provided at the upper end of the shell 30 to lead out the evaporative vapor generated from the inner peripheral surface of the heating element RO to the outside of the shell 30. A concentrated liquid discharge pipe 32 is connected to the shell 30 for discharging the concentrated liquid concentrated on the inner peripheral surface of the shell 30 to the outside of the shell 30. The heating element B is supported by partition plates 33a and 33b arranged at the upper and lower parts of the shell 30, and a ring-shaped hermetic seal is formed around the outer periphery of the heating element B by the partition plates 33a and 33b. A space 34 is formed. Further, in the figure, 35 is a heating steam inlet provided on the upper peripheral surface of the shell 30 for supplying heating steam into the space 4, and 36 is a heating steam inlet provided in the upper peripheral surface of the shell 30 for discharging the heating steam supplied into the space 34 to the outside of the shell 30. In order to
1 is a heated fluid supply cylinder whose tip end is opened on the upper surface of a partition plate 33a disposed in the upper part of the shell 30.

A space 3 provided from the heated steam inlet 35 to the outer periphery of the heating element B of the thin film falling type evaporator having the above configuration.
At the same time as the heating steam was introduced into the heating element 4, the heated fluid was supplied from the heated fluid supply cylinder 37 to the upper surface of the partition plate 33a, and the heating steam passed through the space 34 provided around the outer periphery of the heating element 4. After, Ciel 30
It is discharged to the outside from a discharge port 36 provided on the lower circumferential surface. On the other hand, the heated fluid supplied from the heated fluid supply cylinder 37 to the upper surface of the partition plate 33a flows from the upper surface of the partition plate 33a to the inner circumferential surface of heating element B, and flows into the inner circumferential surface of heating element B. It flows down the inner circumferential surface of the heating element B along the provided inclined groove A while turning around on the inner circumferential surface of the heating element B. At this time, heat exchange is performed with the heating steam flowing around the outer periphery of the heating element B, a part of the fluid to be heated is evaporated, and the evaporated steam is transferred to the evaporative steam outlet 31 provided at the upper end of the shell 30. from there to the next stage of equipment. The fluid to be heated that has not evaporated from the inner circumferential surface of the heating element RO falls from the lower end of the heating element RO to the bottom of the shell 30 and passes through the concentrate discharge pipe 32 connected to the bottom of the shell 30 to the outside. derived.

In the above two embodiments, only one cylindrical heating element B is housed in the shells 21 and 30, but a plurality of heating elements B may be housed in the shells 21 and 30. , heating steam and heated fluid may be supplied to the inner peripheral surface and outer peripheral surface of each heating element. In addition, a plurality of heating elements RO having different diameters are prepared, and the heating elements RO are arranged concentrically within the shells 21 and 30, and heating steam and heat are placed in the space formed between each heating element RO. The fluid to be heated may be supplied alternately. Also, Ciel 2
The shapes of 1 and 30 may be other than cylindrical.

Effects of the Invention As described above, if the heating element housed in the shell is formed into a cylindrical shape and inclined grooves are provided on the inner and outer peripheral surfaces, heat can be transferred without increasing the overall length of the heating element. You can make the length longer. Therefore, the total length of the entire device in the height direction can be shortened, and the thin film falling type evaporator can be downsized. Furthermore, if an inclined groove is provided on the circumferential surface of the heating element, when the heated fluid flows down the circumferential surface of the heating element, the heated fluid flows down along the inclined groove, which prevents liquid drift from occurring. can be prevented.

[Brief explanation of the drawing]

FIG. 1 shows a first example of a thin film falling type evaporator according to the present invention.
FIG. 2 is a partial sectional view showing the second embodiment; FIGS. 3 to 6 are explanatory views for explaining the method of manufacturing a heating element according to the present invention; FIG. 7 is a perspective view showing a conventional example of a thin film falling type evaporator. A... Slanted groove, B... Heating element, 21, 30...
...Ciel.

Claims (1)

[Claims] 1 Consisting of a heating element that is cylindrical and has inclined grooves on its inner and outer circumferential surfaces, and a shell that houses this heating element, the outer and inner circumferential surfaces of the heating element that are housed in the shell. A thin film falling type evaporator characterized in that heat exchange is performed by supplying two types of fluids to each.