KR101611364B1 - Channel type recuperator - Google Patents

Abstract

Disclosed is a channel type-heat exchanger. According to an embodiment of the invention, the channel type-heat exchanger comprises an intake hood, an exhaust hood, tube insertion holes, a tube and a bushing. The intake hood forms an intake flow path allowing combustion gas to be supplied. The exhaust hood forms an exhaust flow path allows the combustion gas undergone heat exchange to flow. Each tube insertion hole is formed to pass through the intake hood and the exhaust hood. The tube has both ends having a protruding end part passing through the tube insertion hole to protrude to the inner space of a corresponding hood and connects the intake flow path with the exhaust flow path to allow heat exchange between waste gas at high temperature, which flows outside, and the combustion gas flowing inside. The bushing is inserted into and is coupled to the tube insertion hole to cover the outer surface of the tube and guides a flow in the longitudinal direction depending on thermal expansion and contraction of the tube or blocks deformation of the tube due to collision with the waste gas. According to the present invention, deformation due to thermal stress is allowed without a need for a welded part fixing the tube to be in contact with the waste gas at high temperature.

Description

{CHANNEL TYPE RECUPERATOR}

The present invention relates to a channel type heat exchanger, and more particularly, to a channel type heat exchanger capable of preventing deformation and corrosion of a tube.

Generally, a heat exchanger is used to recover heat from waste gas discharged from a heating furnace for manufacturing hot-rolled steel sheets. A heat exchanger is used to realize energy saving by collecting heat from the waste gas discharged from the combustion section for heating the heating furnace and preheating the combustion air to be used in the combustion section. The channel type heat exchanger of the heat exchanger has a very dense structure configured to transfer a large amount of heat by a plurality of steel tubes, and is installed in various combustion gas ducts for industrial purposes to preheat the combustion gas. The hood to which the flue gas is supplied and the hood through which the preheated flue gas flows are connected to communicate with each other through the tube, the waste gas flows to the outside of the tube, the unheated flue gas flows to the inside of the tube, .

On the other hand, the tube in contact with the waste gas is frequently exposed to an environment where corrosion can occur due to acid components contained in the waste gas and high temperature heat, so that the tube is in a structure and chemically weak state. Various schemes are being considered.

Published Utility Model Publication No. 89-7356 (published May 16, 1989) Open Patent Publication No. 2012-0001224 (2012.04.04 release) Published Patent Publication No. 2012-0011410 (Published Feb. 20, 2012)

Embodiments of the present invention are intended to provide a channel-type heat exchanger in which the welding portion for fixing the tube can allow deformation due to thermal stress without contacting the hot waste gas.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an exhaust gas purifying apparatus comprising: an intake hood for forming an intake passage to which combustion gas is supplied; an exhaust hood for forming an exhaust passage through which heat is exchanged with the combustion gas; A high-temperature waste gas flowing outside from the intake passage and the exhaust passage, the high-temperature waste gas having a tube insertion hole and both end portions penetrating the tube insertion hole and protruding into the inner space of the corresponding hood, Wherein the combustion gas is inserted into the tube insertion hole so as to surround the heat exchange tube and the tube insertion hole to guide the movement of the tube in the longitudinal direction during thermal expansion or heat shrinking, A channel-type heat exchanger including a bush for preventing the heat exchanger from being blown out can be provided.

Further, the bush includes a hollow cylindrical body inserted into the tube insertion hole, and a flange extended outward from one end of the body and welded to the corresponding inner surface of the hood.

The first protruding end of the tube protruding into the intake passage may be welded to the adjacent flange.

Further comprising a bellows provided so as to surround an outer circumferential surface of a second projecting end portion of the tube protruding from the exhaust flow passage, the bellows being welded to one end of the flange adjacent to the other end, As shown in FIG.

The inner surface of the other end of the body may be provided with an inclined surface for preventing damage of the tube due to stress concentration when the tube is bent due to collision of the waste gas.

And an inner tube inserted and coupled inside the first projecting end to prevent cold corrosion of the tube.

Further, the inner tube may be formed in a cone shape whose width gradually decreases from the upper portion to the lower portion.

Further comprising a bellows disposed so as to surround the outer circumferential surface of the protruding end protruding respectively from the intake passage and the exhaust passage, wherein the bellows is welded to the flange, one end of which is adjacent to the flange, As shown in FIG.

And a flange formed on a welded portion of the flange inserted into the tube insertion hole and welded to an inner surface of a corresponding hood, on a welded portion of the first projected end and the flange, and on one end of the flange and the second projected end The welded portions of the other end of the bellows may be arranged in the inner space of the corresponding hood so as not to be exposed to the waste gas.

Further, the bush may be provided in the form of a block having a plurality of hollow portions provided through a plurality of tubes.

Embodiments of the present invention include a method of inserting a tube that performs heat exchange with waste gas into a bush, joining the tube through a weld in a hood supplied with a non-corrosive combustion gas, and attaching a bellows to allow thermal deformation of the tube to absorb thermal expansion Thereby preventing high-temperature corrosion and low-temperature corrosion, as well as preventing tube bending that can occur during thermal expansion of the tube, thereby preventing damage to the bellows.

1 shows an internal structure of a channel type heat exchanger according to a first embodiment of the present invention.
2 is a perspective view showing a tube coupling structure inside an intake hood according to a first embodiment of the present invention.
3 is a perspective view showing a tube coupling structure inside an exhaust hood according to the first embodiment of the present invention.
4 shows an internal structure of a channel type heat exchanger according to a second embodiment of the present invention.
FIG. 5 illustrates an internal structure of a channel type heat exchanger according to a third embodiment of the present invention.
6 is a perspective view illustrating a bush according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Also, terms including ordinals such as " first, " " second, " and the like can be used to describe various elements, but the elements are not limited by terms. Terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terms used in the present application are used to illustrate the embodiments and are not intended to limit or limit the invention, and the singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprise", "comprising", and the like are intended to specify the presence of stated features, integers, steps, components, or combinations thereof, and may include one or more other features, Steps, elements, or combinations thereof, as a matter of convenience, without departing from the spirit and scope of the invention. Also, when a part is referred to as being "connected" to another part, it includes not only a direct connection but also an indirect connection between the other parts.

FIG. 1 is a perspective view showing the internal structure of a channel type heat exchanger according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a tube coupling structure in an intake hood according to a first embodiment of the present invention, 3 is a perspective view showing a tube coupling structure inside the exhaust hood according to the first embodiment of the present invention.

1 to 3, the channel type heat exchanger 10 according to the first embodiment of the present invention is connected to a combustion gas duct of various industries for preheating combustion gas to recover the waste heat of the waste gas, .

The channel type heat exchanger 10 includes an intake hood 20 in which an intake passage 21 to which combustion gas is supplied is formed and an exhaust passage 20 in which a combustion gas heat- And a plurality of tubes 40 connecting the intake hood 20 and the exhaust hood 30 to communicate the intake passage 21 and the exhaust passage 31 with each other .

The low temperature combustion gas supplied to the intake passage 21 of the intake hood 20 flows along the inside of the tube 40 and is then supplied to the exhaust passage 31 of the exhaust hood 30, Exchanged with the high temperature waste gas flowing outside the tube 40 while flowing along the inside of the tube 40, and is supplied to the exhaust flow path 31.

The tube 40 to which the both ends of the intake hood 20 and the exhaust hood 30 are connected comes into contact with the waste gas at a high temperature so that not only a local external force is applied but also corrosion due to the acid component contained in the high- The structure in which the tube 40 is connected to the intake hood 20 and the exhaust hood 30 is important for extending the service life.

Therefore, in the first embodiment of the present invention, when the tube 40 is coupled to the hoods 20 and 30, thermal stress or deformation of the tube 40 due to high temperature waste gas is absorbed to prevent excessive stress , A relatively weak welded portion provides a bonded structure that is not exposed to the corrosive environment, thereby providing a bonding structure capable of reducing the occurrence of corrosion.

A bush 50 is inserted into the tube insertion holes 22 and 32 formed in the hoods 20 and 30 so that the opposite ends of the tube 40 pass through, The tube 40 is prevented from bending due to the concentration of stress in the tube insertion holes 22 and 32 when the waste gas having a high flow velocity collides against the tube 40 .

The bush 50 may be made of a material such as stainless steel (SUS), aluminum alloy, titanium alloy, or inconel having excellent corrosion resistance and heat resistance. The bush 50 includes a hollow body 51, And a flange 52 having a diameter expanded outward at one end of the flange 52.

When the bush 50 is inserted into the tube insertion holes 22 and 32, the body 51 can be brought into close contact with the inner circumferential surface of the corresponding tube insertion hole 22 and 32, (23, 33) of the base (20, 30).

The hollow portion 53 of the body 51 is formed along the longitudinal direction of the tube 40 so as to perform a guiding function to prevent warpage by permitting deformation in the longitudinal direction when the tube 40 is thermally expanded or heat- The tube 40 may be extended to be in surface contact with the outer surface of the tube 40. When the tube 40 is warped due to the collision of the waste gas on the inner surface of the lower end of the body 51 at the other end, The inclined surface 54 may be provided so as to have a larger inner diameter from the upper portion to the lower portion.

The flange 52 has a cross sectional area whose diameter is extended outward from the upper end of the body 51. When the bush 50 is inserted into the corresponding tube insertion hole 22 or 32, The inner surfaces 23 and 33 of the hoods 20 and 30 can be tightly held.

The bushing 50 is welded to the tube insertion holes 22 and 22 by welding the inner surfaces 23 and 33 of the corresponding hoods 20 and 30 along the outer circumferential surface of the flange 52 to form the welded portion 55 , 32 to prevent the welds from being exposed to the high temperature waste gas.

The first protrusion of the tube 40 protruding into the intake passage 21 through the bushing 50 provided in the tube insertion hole 22 formed in the intake hood 20, The first projecting end portion 41 of the tube 40 and the bushing 50 are welded to each other by welding to the upper surface of the flange 52 of the adjacent bushing 50 along the circumference of the end portion 41 to form the welded portion 57. [ Can be fixed.

The welded portions 55 and 57 for fixing one side of the tube 40 to the intake hood 20 are disposed in the internal space of the intake hood 20 and are not exposed to the space where the high temperature waste gas flows It is possible to suppress the occurrence of corrosion.

Alternatively, the inner space of the exhaust hood 30, that is, the second portion of the tube 40 protruding to the exhaust flow path 31, passes through the bush 50 provided in the tube insertion hole 32 formed in the exhaust hood 30, The protruding end portion 43 is provided with a bellows 60 for enclosing the outer surface of the second protruding end portion 43 of the tube 40 so as to allow deformation due to thermal expansion or thermal contraction of the tube 40, May be provided.

The bellows 60 is formed by stacking a plurality of sheets of rolled metal foil sheets in a circular plate shape and welding them by crossing the inner and outer circumferences of the bellows 60 so as to have elasticity and airtightness. A pair of welding bodies 61 and 62, and a corrugation 63 connecting the pair of welding bodies 61 and 62 to provide elasticity.

The bellows 60 is welded to and welded to the upper surface of the adjacent flange 52 along the circumference of the outer circumferential surface of the one side welding body 62, And the outer surface of the upper end of the protruding end portion 43 of the outer tube 43. [

With such a configuration, even if the tube 40 is thermally expanded and / or bent due to the high temperature waste gas, the bushing 50 can be prevented from bending due to the guide function of the bushing 50, It is possible to prevent the bellows 60 from being damaged by the force in the direction of the eccentricity applied to the bellows 60. As a result,

The welded portion 55 of the flange 52 inserted into the tube insertion hole 32 and welded to the inner surface of the exhaust hood 30 and the welded portion 55 of the flange 52 and one end of the bellows 60, 2 projecting end portions 43 and welding portions 58 and 59 at the other end of the bellows 60 are disposed in the inner space of the exhaust hood 30 so that they are not exposed to the space where the high temperature waste gas flows, .

Hereinafter, a channel type heat exchanger according to a second embodiment of the present invention will be described. Hereinafter, the same reference numerals are assigned to constituent elements having the same function, and a detailed description thereof will be omitted.

4, in the second embodiment of the present invention, in order to prevent low-temperature corrosion of the tube 40, an inner tube (not shown) is formed inside the first projecting end portion 41 of the tube 40 communicating with the intake passage 21 70 are inserted and installed in the first embodiment.

The inner tube 70 is inserted into the first projecting end portion 41 of the tube 40 into which the combustion gas flows so that the combustion gas below the dew point is prevented from directly contacting the tube 40, To prevent the low temperature corrosion that may occur in the tube 40 when the temperature of the combustion gas supplied to the tube 40 is below the dew point.

The inner tube 70 is provided in a cone shape whose width gradually decreases from the upper portion to the lower portion and is supplied to the exhaust passage 31 through the tube 40 by increasing the flow rate discharged from the inner tube 70 The flow of the combustion gas can be smoothly performed.

With this structure, in the channel type heat exchanger according to the second embodiment of the present invention, low temperature corrosion of the tube 40 in the vicinity of the intake hood 20 side where the combustion gas flows is prevented, Temperature bending of the tube 40 by the bushing 50 during deformation due to thermal stress of the tube 40 is prevented so that the bellows 60 is prevented from being bent in the longitudinal direction It is possible to prevent breakage of the bellows 60 due to the biasing force.

Hereinafter, a channel type heat exchanger according to a third embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. The third embodiment of the present invention has the same configuration as the first embodiment except for the configuration in which a block-shaped bush is installed.

7 and 8, the bush 50a is provided in the form of a block having a plurality of hollow portions 53a through which the both ends of the tubes 40 are inserted, and the bushes 50a are formed in the hoods 20, And can be inserted into the tube insertion holes 22 and 32.

The bush 50a is welded to the inner surfaces 23 and 33 of the corresponding hoods 20 and 30 along the outer circumferential surface of the flange 52a and is connected to a plurality of tubes 40 may be mounted.

The outer surfaces of the first projecting end portions 41 of the plurality of tubes 40 projecting to the intake flow path 21 are welded to the upper surface of the bushing 50a and are connected to the exhaust passage 31 The protruding second projecting end portion 43 may be arranged so as to be surrounded by the bellows 60 whose both ends are welded to the upper surface of the bushing 50a and the outer surface of the second projecting end portion 43, respectively.

With such a configuration, the installation efficiency of the bush is improved as compared with the first embodiment, and the welded portion with the tube insertion holes 22 and 32 is reduced, thereby preventing damage due to welding heat.

The foregoing has shown and described specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims.

20: intake hood, 21: intake air passage,
30: exhaust hood, 31: exhaust passage,
40: tube, 41: first projecting end,
43: second projecting end, 50: bushing,
51: body, 52: flange,
54: inclined surface, 60: bellows,
70: Inner tube.

Claims (9)

An intake hood for forming an intake passage to which combustion gas is supplied;
An exhaust hood for forming an exhaust passage through which the heat-exchanged combustion gas flows;
A tube insertion hole formed through the intake hood and the exhaust hood, respectively;
Wherein the combustion gas has a protruding end portion that has both ends penetrating the tube insertion hole and protruding into the inner space of the corresponding hood and communicates with the intake passage and the exhaust passage, A tube to be exchanged; And
And a bush which is inserted into the tube insertion hole so as to surround the outer surface of the tube and guides the longitudinal movement due to thermal expansion and contraction of the tube or blocks the deformation of the tube due to the collision of the waste gas. . The method according to claim 1,
The bush includes:
A hollow cylindrical body inserted into the tube insertion hole and press-
And a flange extending outwardly from one end of the body and welded to the corresponding inner surface of the hood. The method according to claim 1,
Wherein said bushing is provided in the form of a block having a plurality of hollow portions provided with a plurality of tubes penetrating therethrough and a flange extending outward at one end of said bushing and welded to and in contact with the corresponding inner surface of the hood, group. The method according to claim 2 or 3,
And the first projecting end of the tube protruding into the intake passage is welded to the flange of the adjacent bush. The method according to claim 2 or 3,
Further comprising a bellows installed to surround an outer circumferential surface of the second projecting end portion of the tube protruding from the exhaust passage,
Wherein the bellows is welded at one end to the flange of the adjacent bush and the other end is welded to the outer surface of the second projecting end. 3. The method of claim 2,
And an inclined surface for preventing breakage of the tube due to concentration of stress at the time of bending of the tube due to collision of the waste gas is provided on the inner side surface of the other end of the body. 5. The method of claim 4,
Further comprising an inner tube inserted and coupled within the first projecting end to prevent cold corrosion of the tube. 8. The method of claim 7,
Wherein the inner tube is formed in a cone shape whose width gradually decreases from the upper portion to the lower portion. The method according to claim 2 or 3,
The protruding end portion includes a first protruding end portion protruding into the intake passage and a second protruding end portion protruding from the exhaust passage,
And a bellows disposed at the second projecting end to surround the outer surface of the second projecting end,
A flange formed on a welded portion of the flange inserted into the tube insertion hole and welded to an inner surface of a corresponding hood, a welded portion of the flange and the flange, and one end of the flange and the second projected end, And the welded portions of the other end of the bellows are disposed in the inner space of the corresponding hood so as not to be exposed to the waste gas.

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