CN216456938U

CN216456938U - Falling film evaporator

Info

Publication number: CN216456938U
Application number: CN202122524213.2U
Authority: CN
Inventors: 韩军; 刘致远; 于中原; 刘冬; 陈悦
Original assignee: Beijing Guangsha Huanneng Technology Co ltd
Current assignee: Beijing Guangsha Huanneng Technology Co ltd
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2022-05-10
Anticipated expiration: 2031-10-20

Abstract

The utility model discloses a falling film evaporator which comprises a tube plate, wherein a heat exchange tube is arranged on one side of the tube plate, which is back to a liquid material inlet, and a tube end distributor is arranged on one side of the tube plate, which faces the liquid material inlet, and is communicated with the heat exchange tube. And one end of the pipe end distributor, which faces the heat exchange pipe, is provided with an inclined groove which penetrates through the inner wall and the outer wall. The pipe end distributor is arranged at the end part of the heat exchange pipe, and the inclined grooves are formed in the pipe end distributor, so that liquid materials can rotate and flow when entering the heat exchange pipe, the liquid materials are fully contacted with the wall of the heat exchange pipe, and a film forming effect is achieved.

Description

Falling film evaporator

Technical Field

The utility model relates to the technical field of chemical equipment, in particular to a falling film evaporator.

Background

The falling film evaporator is a heat exchanger which makes liquid flow downwards along a heat transfer surface to form a liquid film for heat exchange, and is one of evaporation equipment. The falling film evaporator has the advantages of short material retention time, small material stagnation amount, small pressure drop, large heat transfer coefficient and the like, so that the falling film evaporator is widely applied to the industries of chemical engineering, seawater desalination, medicines, foods, paper making and the like. The feed liquid of the vertical falling-film evaporator does not bear the static pressure of a liquid column during evaporation, so that the loss of effective heat transfer temperature difference caused by the static pressure is eliminated, the heat transfer rate is higher under the low temperature difference, and the vertical falling-film evaporator is suitable for a multi-effect evaporation system, and can be operated once through direct current or circularly. When heat-sensitive materials are treated, the wall temperature of a heat exchange tube needs to be limited and the residence time needs to be reduced, meanwhile, in order to reduce the fluid temperature, heat is generally required to be conducted under vacuum, and at the moment, the falling-film evaporator can achieve the minimum pressure drop and the minimum residence time and obtain a good heat transfer effect. For the concentration of dilute solutions, falling film evaporators tend to be the preferred type.

The thermal calculations for the present falling film evaporator can be performed using HTRI or EDR software design, the results of which are based on the assumption that all the fluid is distributed evenly in each heat exchange tube and a stable and uniform liquid film is formed on the wall. The reasonable pipe end distributor can make the feed liquid uniformly form film in the pipe, and the quality of the structure of the distributor has direct influence on the film forming effect, the stability of the liquid film and the control of the falling liquid density, thereby directly influencing the heat exchange efficiency of the evaporator. It can be seen that the tube end distributor is the key to the falling film evaporator.

SUMMERY OF THE UTILITY MODEL

In view of the above technical problems in the related art, the present invention provides a falling film evaporator capable of overcoming the above disadvantages of the prior art.

In order to achieve the technical purpose, the technical scheme of the utility model is realized as follows:

the falling film evaporator comprises a tube plate, wherein a heat exchange tube is arranged on one side, back to a material inlet, of the tube plate, a tube end distributor is arranged on one side, facing the material inlet, of the tube plate, and the tube end distributor is communicated with the heat exchange tube. And one end of the pipe end distributor, which faces the heat exchange pipe, is provided with an inclined groove which runs through the inner wall and the outer wall.

Furthermore, 4 inclined grooves are formed in the inclined grooves and are uniformly distributed on the periphery of the pipe end distributor, so that liquid materials are in contact with the pipe wall of the heat exchange pipe more uniformly.

Furthermore, the distance between the inclined groove and the end part of the pipe end distributor facing one end of the pipe plate is 20-30mm, so that a certain liquid level height can be formed after the materials enter the pipe box through the material inlet, and the liquid materials are uniformly distributed in each heat exchange pipe until the liquid level height reaches the position of the inclined groove.

Furthermore, the groove width of the inclined groove is 2-5mm, and the groove length of the inclined groove is 20-30 mm.

Furthermore, the top of one end of the pipe section distributor, which is back to the heat exchange pipe, is provided with a splash guard to prevent the liquid phase from directly dripping into the heat exchange pipe from the distribution plate on the top to affect the liquid phase film formation.

Furthermore, the end part of the pipe section distributor, which is back to the end part of the heat exchange pipe, is provided with a circulation groove.

Furthermore, 3 circulation grooves are uniformly distributed around the pipe end distributor, the width of each circulation groove is 15-25mm, and the length of each circulation groove is 15-25 mm.

The utility model has the beneficial effects that: the pipe end distributor is arranged at the end part of the heat exchange pipe, and the inclined grooves are formed in the pipe end distributor, so that liquid materials can rotate and flow when entering the heat exchange pipe, the liquid materials are fully contacted with the wall of the heat exchange pipe, and a film forming effect is achieved. It should be noted that, the size of the slot is obtained by the continuous experiment of the skilled person, and the design of the pipe end distributor as the final distributor structure before entering the heat exchange pipe is determined by the quality of the design. To ensure complete wetting of the tube. The pipe end distributor has strict flow calculation, overlarge flow can cause the liquid film to be too thick, and finally, the liquid film cannot be sufficiently evaporated, and the liquid film is too thin, so that the liquid does not reach the bottommost part of the heat exchange pipe, and is evaporated to dryness, and the wall dryness phenomenon is caused. The level calculation needs to meet different operating conditions.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a falling film evaporator according to an embodiment of the present invention.

Fig. 2 is a schematic view of a portion of the structure of fig. 1A.

Fig. 3 is a schematic diagram of the cross-sectional structure of the inclined groove of the falling film evaporator according to the embodiment of the utility model.

Fig. 4 is a schematic diagram of the cross-sectional structure of the flow groove of the falling film evaporator according to the embodiment of the utility model.

In the figure: the method comprises the following steps of 1-pipe end distributor, 2-heat exchange pipe, 3-pipe plate, 4-inclined groove, 5-circulation groove, 6-splash guard, 7-pipe box and 8-material inlet.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

As shown in fig. 1 to 4, the falling film evaporator according to the embodiment of the utility model comprises a tube plate 3, wherein a heat exchange tube 2 is arranged on one side of the tube plate 3, which faces away from a material inlet, a tube end distributor 1 is arranged on one side of the tube plate 3, which faces towards the material inlet, and the tube end distributor 1 is communicated with the heat exchange tube 2.

The pipe end distributor 1 is provided with an inclined groove 4 penetrating through the inner wall and the outer wall at a position facing 20-30mm of one end part of the pipe plate 3. The material forms certain liquid level height after entering pipe case 7 through material entry 8, and liquid material evenly distributed is in each heat exchange tube 2 when liquid level height reaches the inclined groove 4 position. The groove width of the inclined groove 4 is 2-5mm, and the groove length of the inclined groove 4 is 20-30 mm.

The top of one end of the pipe section distributor back to the heat exchange pipe 2 is provided with a splash guard 6 to prevent the liquid phase from directly dripping into the heat exchange pipe 2 from the distribution plate on the top to influence the liquid phase film formation. The end part of the pipe section distributor, which is back to one end of the heat exchange pipe 2, is provided with 3 circulation grooves 5, the circulation grooves 5 are uniformly distributed around the pipe end distributor 1, the groove width of the circulation grooves 5 is 15-25mm, and the groove length of the circulation grooves 5 is 15-25 mm.

In order to facilitate understanding of the above-described technical aspects of the present invention, the above-described technical aspects of the present invention will be described in detail below in terms of specific usage.

When the falling film evaporator is used specifically, materials enter the tube box 7 through the material inlet 8, a certain liquid level height is formed at a position, 20-30mm reserved on the tube end distributor 1 and facing the tube plate 3, when the liquid level height is higher than the inclined groove 4 of the tube end distributor 1, the liquid materials are uniformly distributed in each heat exchange tube 2 and flow from top to bottom in a uniform film shape under the action of gravity, vacuum induction and air flow until the flow of the liquid material inlet is equal to the flow of the liquid materials flowing into the heat exchange tubes 2 from the tube end distributor 1, and the liquid level is balanced. The grooving part of the distributor is an inclined grooving, so that liquid material can rotate and flow when just entering the heat exchange tube 2, and the liquid material is fully contacted with the wall of the heat exchange tube 2, thereby playing a role in film formation.

In summary, according to the above technical solution of the present invention, the tube end distributor 1 is disposed at the end of the heat exchange tube 2, and the inclined groove 4 is formed in the tube end distributor 1, so that the liquid material rotates and flows when entering the heat exchange tube 2, and the liquid material is sufficiently contacted with the wall of the heat exchange tube 2, thereby forming a film. It should be noted that, the size of the slot is obtained by the continuous experiment of the skilled person, and the pipe end distributor 1 is used as the final distributor structure before entering the heat exchange pipe 2, and the design quality thereof is determinative to the material film distribution. To ensure complete wetting of the tube. The pipe end distributor 1 has strict flow calculation, the excessive flow can cause the liquid film to be too thick, and finally, the liquid film can not be sufficiently evaporated, and the liquid film is too thin, so that the liquid can be evaporated to dryness without reaching the bottommost part of the heat exchange pipe 2, and the wall dryness phenomenon can occur. The level calculation needs to meet different operating conditions.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a falling film evaporator, includes tube sheet (3), tube sheet (3) material entry (8) one side dorsad is provided with heat exchange tube (2), and tube sheet (3) are provided with pipe end distributor (1) towards material entry (8) one side, pipe end distributor (1) and heat exchange tube (2) switch-on, pipe end distributor (1) are provided with inclined groove (4) of lining up the inside and outside wall towards heat exchange tube (2) one end.

2. The falling film evaporator of claim 1, wherein: the inclined grooves (4) are provided with 4 grooves which are uniformly distributed around the pipe end distributor (1).

3. A falling film evaporator according to claim 1 or claim 2 wherein: the distance between the inclined groove (4) and the end part of the pipe end distributor (1) facing the pipe plate (3) is 20-30 mm.

4. A falling film evaporator according to claim 1 or claim 2 wherein: the groove width of the inclined groove (4) is 2-5mm, and the groove length of the inclined groove (4) is 20-30 mm.

5. The falling film evaporator of claim 4, wherein: and a splash-proof plate (6) is arranged at the top of one end of the pipe end distributor (1) back to the heat exchange pipe (2).

6. The falling film evaporator of claim 4, wherein: the end part of the pipe end distributor (1), which is back to one end of the heat exchange pipe (2), is provided with a circulation groove (5).

7. The falling film evaporator of claim 6, wherein: the number of the circulation grooves (5) is 3, the circulation grooves are uniformly distributed on the periphery of the pipe end distributor (1), the width of each circulation groove (5) is 15-25mm, and the length of each circulation groove (5) is 15-25 mm.