RU2358218C1 - Spiral-type heat exchanger and its fabrication method - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to thermotechnics immediately dealing with design of spiral-type heat exchangers and their fabrication methods and is to find application in chemical, food, oil-processing and other industries. The proposed spiral-type heat exchanger is composed of a housing with inlet and outlet nipples, a double-channel spiral fabricated of a sheet material, elements providing for stability of spacing between the spiral sheets, stopper pieces fitted in the channels both sides of the spiral, channel end seals and gasketed caps covering the channel ends. The elements providing for stability of spacing between the spiral sheets are represented by zigzag shaped spacers arranged along the whole of the spiral length. Under the proposed method the spiral-type heat exchanger is fabricated as follows: the zigzag shaped spacers are placed between the sheets during the spiral coiling; then the stopper pieces are laid onto the side edges of the zigzag spacer terminal rows and the channel space between the spiral butt ends and the stopper pieces becomes filled with a sealant material. The heat exchanger housing is pre-fabricated as composed of two semicylinders; after that the pre-coiled spiral is encased with the two semicylinders that become bonded along the whole of the housing length.

EFFECT: heat exchanger structural simplification, simplification of spiral heat exchanger fabrication process and fabrication costs reduction.

7 cl, 6 dwg

Description

The invention relates to devices for conducting heat transfer processes and can be used in chemical, food and oil refining and other industries.

In various industries, heat exchangers are widely used, which serve to transfer heat from one medium to another through a wall of heat-conducting material that separates these media. Among them are shell-and-tube, lamellar, spiral, coil, etc. heat exchangers that differ in the design of the heat exchange surface (RF Patent No. 2121122, IPC F28D 7/00; No. 2151991, IPC F28D 3/02; No. 2156423, IPC F28D 3/00, 09/20/2000; No. 2166716, IPC F28D 3 / 00).

Known spiral heat exchanger containing a cylindrical body in which are placed heat transfer surfaces formed from elements representing a pair of spiral-shaped walls welded in pairs along the contour, forming an internal spiral slotted channel. In a section perpendicular to the axis of the apparatus, spiral-shaped walls form a heat-exchange surface in a spiral of Archimedes. The internal spiral cavities of the heat-exchange elements communicate with the collectors of the input and output of one medium, and the external with the collectors of the input and output of another medium (V.V. Burenin. New recuperative heat exchangers for oil refining and petrochemical industries. "Oil Refining and Petrochemicals", No. 3, 2005 pg. 44-45).

Known spiral heat exchanger containing channels for the working environment, made of rolled tape, in one of which are pins equipped with turbulators made of tape, twisted in the longitudinal direction (RF Patent No. 2156423, IPC F28D 7/04; 09/20/2000 )

Known spiral heat exchanger containing two slotted channels for the passage of coolants formed by two sheets folded into a spiral with elements of remote location, external and internal collectors and mechanical seals (RF Patent No. 2306517, IPC F28D 7/04; 04.10.2006).

A common drawback of these technical solutions is the complexity of the design, the low-tech manufacturing of the heat exchanger, as well as the increased weight due to the presence of complex sealing units, which accounts for the high manufacturing cost.

Known spiral heat exchanger containing a housing with inlet and outlet pipes, a two-channel spiral of sheets, parts that fix the distance between the sheets of the spiral, stops placed in the channels on both sides of the spiral, sealing the ends of the channels, covers with gaskets on the ends of the spiral (N.V. Baranovsky and other Plate and spiral heat exchangers. Engineering, M. 1973, S. 262-269).

By the combination of similar features, this spiral heat exchanger is closest to the inventive spiral heat exchanger and is taken as a prototype.

However, this spiral heat exchanger has a number of disadvantages: in it, pins welded to one of the sheets are used as parts fixing the distance between the sheets of the spiral and to create the rigidity of the sheets. The spiral is sealed using stops made of a tape inserted into the channel and welded to the edges of the sheets (N.V. Baranovsky and others. Plate and spiral heat exchangers. Mechanical Engineering, Moscow 1973, pp. 263-264, Fig. 142, options a , b, c, d). This leads to a significant complication of the manufacture of the heat exchanger, especially in the case of its use for heat carriers with high temperatures (above 400 ° C) and in aggressive and corrosive environments. In these cases, the heat exchanger requires the use of alloy steels, which leads to considerable complexity and high cost when welding parts. Sealing the ends with only a gasket in) or a U-shaped cuff - var. d) does not prevent the possibility of flow of coolant from one channel to another. In addition, the heat exchanger housing is made of a single piece in the form of a cylinder, which makes it difficult to install the spiral assembled in a single unit into the housing.

The first task according to the invention:

- simplification and cheapening of the design of the heat exchanger;

- the exception of the flow of coolant from one channel to another.

The second objective of the invention is to simplify the manufacturing technology of the heat exchanger and, as a result, reduce the cost of its manufacture.

The first task is solved in that the spiral heat exchanger contains a housing with inlet and outlet pipes, a two-channel spiral of sheets, parts that fix the distance between the sheets of the spiral, stops placed in the channels on both sides of the spiral, sealing the ends of the channels, covers with gaskets along the ends of the spiral.

According to the first objective of the invention, the spiral heat exchanger further includes:

- details fixing the distance between the sheets of the spiral, made in the form of zigzag spacers placed along the entire spiral;

- stops laid in channels on two sides of the spiral, placed on the lateral edges of the extreme rows of zigzag spacers;

- a sealing mass filling the space in the channels between the ends of the spiral and the stops to prevent the flow of coolant from one channel to another;

- a housing made of two half-cylinders, fastened to each other after installing the spiral;

- in heat exchangers operating on contaminated working media, zigzag spacers with turbulators, made on the vertical and / or horizontal edges of the zigzag spacers.

The second task according to the invention is solved as follows:

- zigzag spacers are placed between the sheets during the spiral winding process, then stops are placed on the lateral edges of the extreme rows of zigzag spacers, after which the space in the channels between the ends of the spiral and the stops is filled with a sealing mass;

- the heat exchanger casing is preliminarily made of two half-cylinders, then the pre-wound spiral is covered with half-cylinders and fastened to each other along the entire length of the casing.

The invention is illustrated by drawings, where:

figure 1 is a longitudinal section of a heat exchanger,

figure 2 - remote element B in figure 1;

figure 3 is a section AA in figure 1;

figure 4 - remote element In figure 2;

figure 5 - zigzag spacers;

figure 6 - heat exchanger housing assembly.

The spiral heat exchanger consists of a casing 1, a spiral 2 wound from two sheets 3 and 4 onto a core 5. Casing 1 consists of two half-cylinders 1.1 and 1.2 and flanges 1.3. Between the sheets 3 and 4 of the spiral 2 installed zigzag spacers 6 (figure 2).

Zigzag spacers 6 are used in two types - ordinary spacers 6.1 (Fig.5 "a") and spacers with turbulators 6.2. (Fig.5 "b"). Zigzag spacers 6 are made by bending strip steel, with horizontal shelves 6.1.1. and 6.2.1. correspond to the distance between sheets 3 and 4 of the spiral 2 (Fig.2, 5).

The core 5 is divided into two cavities 5.1 and 5.2 (figures 1, 3). The inner edge of the sheet 3 is welded to the longitudinal cylindrical wall of the core cavity 5.1, and the inner edge of the sheet 4 is welded to the longitudinal cylindrical wall of the core cavity 5.2, two channels 7 and 8 are formed in a spiral. The outer edge of the sheet 3 is welded to the longitudinal edge of the semicylinder 1.1, and the outer edge of the sheet 4 is welded to the longitudinal edge of the half cylinder 1.2. In this case, exits from the channels 7 and 8 (Fig. 3) are formed, to which the inlet and outlet pipes 9 and 10 of the housing 1 are welded (Fig. 4).

As the spiral 2 is folded (Fig. 2), zigzag spacers 6 are installed between the sheets of the spiral 3 and 4, and the spacers 6.3, which are closest to the edges of the sheets, are installed one above the other, the remaining spacers are advisable to be placed in adjacent turns of channels in a checkerboard pattern. This sets the channel width.

The spiral 2 wound on the core 5 is covered by half cylinders 1.1 and 1.2 (Figs. 1, 3, 6), fasten them together along the entire length and weld the flanges 1.3, creating a single assembly of the housing 1 and spiral 2.

On the lateral edges of the extreme rows of zigzag spacers 6.3 (figure 2) in the channels 7 and 8 are placed stops 11, for example, in the form of a wire. The channels closest to the ends of the spiral (sheet edges) are filled with a sealing mass 12, and the depth of the stops 11 and the filling of the ends of the channels with a sealing mass 12 are selected from the mandatory condition for excluding the flow of coolant from one channel to another. A gasket 13 is laid on the ends of the spiral 2 in the form of a sheet of sealing material, pressed by the flanges 14 to the ends of the spiral 2 and to the sealing mass 12 filling the channels 7 and 8. Under the pressure of the flange 14, the gasket 13 and the sealing mass 12 in the channels 7 and 8 form a uniform seal.

As a sealing mass for heat exchangers operating in aggressive or corrosive environments and / or high temperatures, thermally expanded graphite or products from graphitized asbestos or other materials with similar properties are used.

To connect with the core cavities 5.1 and 5.2 (FIG. 1), holes are made in the central part of the flanges 14. The inlet and outlet pipes 15 and 16 are connected to the flanges 14.

Thanks to this design of the heat exchanger, reliable separation of the channels is ensured, which eliminates the flow of the coolant from one channel to another.

In heat exchangers operating on contaminated working media, zigzag spacers 6.2, equipped with turbulators 6.2.2, made in the form of short protrusions to create a turbulent in the channel, are installed in the channels through which the contaminated medium is supplied, to reduce the sedimentation of suspended particles on the walls of the channels in the spiral 2 flow.

The distance between the spacers 6 should be selected depending on the strength characteristics of the metal from which the sheets are made, and the pressure drop of the coolants in the channels.

To clean the channels of possible deposits, it is necessary to remove the sealing mass 12 and the stops 11 from the ends of the spiral 2 from the ends of the channels and clean the channels with narrow scrapers.

Claims (7)

1. A spiral heat exchanger comprising a housing with inlet and outlet pipes, a two-channel spiral of sheets, parts fixing the distance between the sheets of the spiral, stops placed in the channels on both sides of the spiral, sealing the ends of the spiral, covers with gaskets on the ends of the spiral, characterized in that the details fixing the distance between the sheets of the spiral are made in the form of zigzag spacers placed along the entire spiral. 2. The spiral heat exchanger according to claim 1, characterized in that the stops laid in the channels on both sides of the spiral are placed on the lateral edges of the extreme rows of zigzag spacers. 3. The spiral heat exchanger according to claim 1, characterized in that the space in the channels between the ends of the spiral and the stops is filled with a sealing mass to prevent the flow of coolant from one channel to another. 4. The spiral heat exchanger according to claim 1, characterized in that the casing is made of two half-cylinders, fastened to each other after installing the spiral. 5. The spiral heat exchanger according to claim 1, characterized in that in heat exchangers operating on contaminated working media, zigzag spacers are provided with turbulators made on the vertical and / or horizontal edges of the zigzag spacers. 6. A method of manufacturing a spiral heat exchanger, characterized by PP.1-5, characterized in that the zigzag spacers are placed between the sheets in the process of winding the spiral, then the stops are placed on the lateral edges of the extreme rows of zigzag spacers, after which the space in the channels between the ends of the spiral and the stops filled with a sealing mass. 7. The method according to claim 6, characterized in that the heat exchanger casing is prefabricated from two half-cylinders, then the pre-wound spiral is covered with half-cylinders and fastened to each other along the entire length of the casing.

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