U.S. patent application number 14/204149 was filed with the patent office on 2014-09-18 for heat exchanger and body therefore, and a method for forming a heat exchanger body.
This patent application is currently assigned to Dejatech GES B.V.. The applicant listed for this patent is Dejatech GES B.V.. Invention is credited to Jan Hubertus DECKERS, Paulus Mathijs Maria THIJSSEN.
Application Number | 20140261241 14/204149 |
Document ID | / |
Family ID | 50102159 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140261241 |
Kind Code |
A1 |
DECKERS; Jan Hubertus ; et
al. |
September 18, 2014 |
HEAT EXCHANGER AND BODY THEREFORE, AND A METHOD FOR FORMING A HEAT
EXCHANGER BODY
Abstract
Heat exchanger, comprising a heat exchanger body made of light
metal or light metal alloy, wherein the body comprises at least a
flue duct and a flame receiving space, wherein the body comprises
two parts at opposite sides of the flue duct and flame receiving
space, said two parts substantially defining said flue duct and
flame receiving space, wherein the flue duct and flame receiving
space define a main flow direction for flue gas between an entry
side of the flame receiving space and an outlet of the flue duct,
wherein each of said parts comprises a first series of ribs
extending into the space between said two parts and having a length
direction substantially perpendicular to the main flow direction
for flue gas, thus defining a meandering flow path of flue gasses
between said flame receiving space and said outlet and a second
series of ribs extending in said flame receiving space, wherein
between the ribs of said second series of opposite parts an open
space is provided.
Inventors: |
DECKERS; Jan Hubertus;
(Belfeld, NL) ; THIJSSEN; Paulus Mathijs Maria;
(Belfeld, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dejatech GES B.V. |
Belfeld |
|
NL |
|
|
Assignee: |
Dejatech GES B.V.
Belfeld
NL
|
Family ID: |
50102159 |
Appl. No.: |
14/204149 |
Filed: |
March 11, 2014 |
Current U.S.
Class: |
122/18.31 ;
29/890.03; 72/253.1 |
Current CPC
Class: |
F28F 2275/025 20130101;
Y10T 29/4935 20150115; F28F 7/02 20130101; F28D 9/0081 20130101;
F28F 13/06 20130101; F28F 2255/16 20130101; Y02B 30/00 20130101;
B21C 23/02 20130101; F24H 1/32 20130101; F24H 9/0026 20130101; Y02B
30/102 20130101; F24H 8/00 20130101; F28F 13/08 20130101; F28F
21/084 20130101; F28F 3/048 20130101; F24H 1/282 20130101; B21D
53/02 20130101; F24H 9/0015 20130101 |
Class at
Publication: |
122/18.31 ;
29/890.03; 72/253.1 |
International
Class: |
F24H 1/28 20060101
F24H001/28; B21C 23/02 20060101 B21C023/02; B21D 53/02 20060101
B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 2013 |
NL |
2010442 |
Claims
1. Heat exchanger, comprising a heat exchanger body made of light
metal or light metal alloy, wherein the body comprises at least a
flue duct and a flame receiving space, wherein the body comprises
two parts at opposite sides of the flue duct and flame receiving
space, said two parts substantially defining said flue duct and
flame receiving space, wherein the flue duct and flame receiving
space define a main flow direction for flue gas between an entry
side of the flame receiving space and an outlet of the flue duct,
wherein each of said parts comprises a first series of ribs
extending into the space between said two parts and having a length
direction substantially perpendicular to the main flow direction
for flue gas, thus defining a meandering flow path of flue gasses
between said flame receiving space and said outlet and a second
series of ribs extending in said flame receiving space, wherein
between the ribs of said second series of opposite parts an open
space is provided.
2. Heat exchanger according to claim 1, wherein the ribs of the
first and second series have a base near a wall of the respective
parts of the body which extends in said length direction
substantially perpendicular to the main flow direction of the flue
gas and preferably all extend parallel to each other.
3. Heat exchanger according to claim 1, wherein the two parts are
made by extrusion, preferably having an extrusion direction
parallel to the length direction of the ribs.
4. Heat exchanger according to claim 1, wherein each of the two
parts is made as a mono-block.
5. Heat exchanger according to claim 1, wherein in side view
perpendicular to the said length direction of the ribs the body has
an average width in a first portion comprising the first series of
ribs which is smaller than the average width of a second portion of
the body comprising the flame receiving space, wherein preferably
in said side view the second portion widens in a direction away
from said first portion, wherein more preferably the first portion
in said side view has a substantially rectangular shape.
6. Heat exchanger according to claim 1, wherein the two parts each
comprise an inner surface from which said ribs extend, wherein the
second series of ribs have a height seen in a direction
perpendicular to said inner surface which increases in a direction
towards the flue duct, such that the ribs closest to the flue duct
are higher than the ribs further away from said flue duct.
7. Heat exchanger according to claim 1, wherein the ribs of the
first series of a first of the two parts extend between the ribs of
the first series of the second of the two parts.
8. Heat exchanger according to claim 7, wherein the ribs of the two
parts extend further between each other near the outlet of the flue
duct than near the flame receiving space, preferably such that the
flue duct between the ribs near the flame receiving space is wider
than near the outlet.
9. Heat exchanger according to claim 1, wherein the ribs of the
first series of opposite parts of the body have facing top
surfaces, positioned such that the ribs of the first series of the
two parts form pairs with a passage between facing top surfaces,
wherein adjacent passages are displaced relative to each other,
such that said passages form part of the meandering flue path.
10. Heat exchanger according to claim 1, wherein at least an number
of the ribs of the first series of the two parts seen in the main
flow direction overlap each other at least 50% of their surface
area, preferably at least 60%, such as for example at least
75%.
11. Heat exchanger according to claim 1, wherein each of the two
parts comprises a series of water duct sections, preferably having
a length direction extending in a direction parallel to the length
direction of the ribs, wherein water duct sections are
interconnected by removing parts of a separating wall between
adjacent sections and/or by water duct connecting sections provided
external from said two parts, for example in end parts connecting
the two parts and closing off the flue duct and flame receiving
space.
12. Heat exchanger according to claim 1, wherein the two parts are
connected to each other by end parts mounted over opposite sides of
the parts, closing off opposite sides of the flue duct and flame
receiving space, wherein the end parts are preferably glued or
bonded to said parts.
13. Heat exchanger according to claim 12, wherein at least one end
part comprises an inlet and/or outlet for a water duct of the heat
exchanger extending along at least part of the two parts.
14. Heat exchanger according to claim 1, wherein at the inlet side
of the flame receiving space a burner is mounted on and/or in the
body, wherein preferably a closing element is mounted over the
outlet of the flue duct, for connecting an exhaust and for forming
a condensate receiving container.
15. Method for forming a heat exchanger body, wherein two parts are
formed by extrusion, each having an inner wall from which parallel
ribs extend, which parts are positioned with the inner surfaces
facing each other and are connected by end parts, such that said
two parts substantially define a flue duct and a flame receiving
space opening into said flue duct, wherein the flue duct and flame
receiving space define a main flow direction for flue gas between
an entry side of the flame receiving space and an outlet of the
flue duct substantially perpendicular to an extrusion direction of
the parts, preferably such that the ribs define a meandering flow
path of flue gasses between said flame receiving space and said
outlet, and wherein between the ribs of said opposite parts in the
flame receiving space an open space is provided.
Description
[0001] The invention relates to a heat exchanger.
[0002] Heat exchanger bodies made of light metal such as aluminum
or aluminum alloy are well known in the art and are commonly cast
using lost core technology. Various embodiments of such heat
exchanger bodies are known from for example Dejatech BV, Belfeld,
NL. Such heat exchanger bodies have been used in many different
heating appliances such as central heating and sanitary water
heating appliances of different manufacturers. Casting provides for
relatively high degrees of designer freedom, but is costly, in
tooling, handling and in machining. Moreover such production
methods are labor intensive and lead to relatively much refuse and
lost materials.
[0003] WO2010/098666 discloses a heat exchanger made using
extrusion of light metal. In this disclosure two parts of a heat
exchanger body are extruded, each comprising a wall and a series of
ribs as partitioning walls for forming flue duct sections or duct
sections. The parts are connected to each other with the ribs
facing each other. End portions of intermediate walls are removed
by machining for forming connections between the sections of the
ducts to form a continuing flue duct. A burner is connected to one
end of the duct, whereas an exhaust is mounted to the opposite end
of the duct. In this disclosure the main flow direction of the flue
gases in the different sections is parallel to the extrusion
direction of the parts.
[0004] A heat exchanger according to WO2010/098666 has the
advantage over cast heat exchangers that the extrusion process is
relatively easy, that no cores have to be removed and that cleaning
of the parts before assembly is relatively easy, if necessary.
Moreover the heat capacity of the heat exchanger can easily be
chosen by cutting off a different length of extruded profile for
forming the parts. The need for machining after extrusion is,
although limited compared to cast heat exchangers, still
significant. Moreover, since of most of the ribs parts need to be
removed, relatively much material still is lost. Furthermore the
contact between gas and the duct walls may not always be
optimal.
[0005] The present disclosure has as an aim to provided an
alternative heat exchanger, or an alternative heat exchanger body.
An aim is to provided a heat exchanger body formed using extrusion
of parts thereof. An aim is to provided a heat exchanger body which
reduces the need for machining and/or the loss of material compared
to known heat exchangers as discussed having comparable capacity.
The present disclosure additionally or alternatively aims at
providing a heat exchanger which has a body made of light metal
which has a high heat exchanging capacity/volume ratio. The present
disclosure additionally or alternatively aims at providing a heat
exchanger which has a body made of light metal which can be
manufactured in an easy and reliable manner, for example using
bonding technology as described in WO2010/098666.
[0006] At least one of these aims separately or in combination can
be achieved with a heat exchanger and/or heat exchanger body and/or
method according to this disclosure.
[0007] In an aspect of the present disclosure a heat exchanger can
be defined by two parts, made by extrusion and comprising an inner
wall with ribs extending therefrom, which parts define an extrusion
direction parallel to a length direction of the ribs, wherein in
assembled condition between the parts and especially between the
ribs a flue duct is defined having a main flow direction which
extends in a direction substantially perpendicular to the extrusion
direction.
[0008] In an aspect of the present disclosure a heat exchanger can
be defined by two parts, made by extrusion and each comprising an
inner wall with ribs extending therefrom, which parts define an
extrusion direction parallel to a length direction of the ribs,
wherein in assembled condition between the parts and especially
between the ribs a flame receiving space is formed, having a main
flow direction extending in a direction substantially perpendicular
to the extrusion direction. The flame receiving space connects to a
flue duct, for example as described in the previous paragraph, and
widens in the opposite direction, ribs of opposite parts being
spaced apart such that between the ribs a free and unobstructed
space is provided.
[0009] In an aspect a heat exchanger according to this disclosure
comprises a heat exchanger body made of light metal or light metal
alloy, wherein the body comprises at least a flue duct and a flame
receiving space, wherein the body comprises two parts at opposite
sides of the flue duct and flame receiving space, said two parts
substantially defining said flue duct and flame receiving space,
wherein the flue duct and flame receiving space define a main flow
direction for flue gas between an entry side of the flame receiving
space and an outlet of the flue duct, wherein each of said parts
comprises a first series of ribs extending into the space between
said two parts and having a length direction substantially
perpendicular to the main flow direction for flue gas, thus
defining a meandering flow path of flue gasses between said flame
receiving space and said outlet and a second series of ribs
extending in said flame receiving space, wherein between the ribs
of said second series of opposite parts an open space is
provided.
[0010] In an aspect a method of the present disclosure can be
defined by forming at least two parts by extrusion, each having an
inner wall from which parallel ribs extend, which parts are
positioned with the inner surfaces facing each other and are
connected by end parts, such that said two parts substantially
define a flue duct and a flame receiving space opening into said
flue duct, wherein the flue duct and flame receiving space define a
main flow direction for flue gas between an entry side of the flame
receiving space and an outlet of the flue duct substantially
perpendicular to an extrusion direction of the parts. In
embodiments the parts may be connected such that the ribs define a
meandering flow path of flue gasses between said flame receiving
space and said outlet, and wherein between the ribs of said
opposite parts in the flame receiving space an open space is
provided.
[0011] The present invention shall be further elucidated in the
following description, with reference to the drawings, in
which:
[0012] FIG. 1 shows a heat exchanger, schematically, in perspective
view, partly broken away;
[0013] FIG. 2 two parts of a heat exchanger body for a heat
exchanger, for example according to FIG. 1, in side view;
[0014] FIG. 3 schematically part of a water duct of a heat
exchanger according to the disclosure, connected to a heating
circuit; and
[0015] FIG. 4 schematically part of an alternative embodiment in
side view.
[0016] In this description different embodiments of heat exchangers
and parts thereof, as well as heating circuits equipped therewith
are disclosed and described by way of example only. In these
embodiments the same or similar parts have the same or similar
reference signs. Combinations of parts of the embodiments shown are
also considered to have been disclosed herein. In this description
a heat exchanger as to be understood as an exchanger for exchanging
heat between heated flue gasses from a burner and water flowing
through one or more water channels within said heat exchanger.
Preferably a flame receiving space is provided over and/or into
which a burner can be inserted, such that said heated flue gasses
are actively created, during use, within said heat exchanger. In an
alternative the burner can be at least partly integrated in the
heat exchanger, for example by extrusion, casting and/or machining.
Such heat exchangers are especially, but not exclusively suitable
in domestic and commercial heating systems such as boilers and
central heating systems, such as for space heating and/or tap water
heating systems.
[0017] In the following description extrusion, possibly combined
with machining of extruded parts, shall be described as an
advantageous means for manufacturing parts of such heat exchanger.
Nevertheless, some or all of these parts can also be made by
casting, such as but not limited to injection moulding, sand or
otherwise lost core moulding or casting or the like, possibly
combined with machining, such as but not limited to grinding,
turning, milling, drilling and the like known machining
methods.
[0018] In this description light metal is at least to be understood
as including non-ferro metal and non-ferro metal alloy having a
density of less than 4500 kg/m.sup.3. Preferred materials are
aluminum and aluminum alloy.
[0019] In this description wording like top and bottom and sides
are used as references only, without limiting the possible
positioning of the heat exchanger or parts thereof in use. In this
description top and bottom are used as defined in FIGS. 1, 2 and 4,
where the flame receiving space is shown at the top and the outlet
for gas is at the bottom.
[0020] In this description words like substantially and about
indicate that slight deviations from a dimension or orientation to
which they refer is allowable, for example less than 20%, more
preferably less than 15%, for example up to 10%.
[0021] In this description bonding has to be understood as forming
an adhesive connection between two or more parts using an elastic
bonding agent. Especially suitable is a glue or adhesive which
after curing is still flexible and elastically deformable.
Preferably the bonding agent is heat resistant to temperatures
above 120.degree. C., preferably above 150.degree. C., more
preferably above 170.degree. C. A glue can be used having a
temperature resistance up to 180.degree. C. or above. A glue can be
used having a use temperature range between about -4 and
+120.degree. C., preferably between about -20 and +150.degree. C.,
more preferably between about -40 and +170.degree. C., even more
preferably between at least -55 and 180.degree. C. or higher (e.g.
PSI S406). A temperature range should be understood as a range of
temperatures in which the glue maintains at least most of its
elastic and bonding properties, such that in a heat exchanger at
least the bonding maintains pressure resistant and fluid and gas
tight. Pressure resistant is in this context to be understood as at
least resistant to pressures in an adjoining space of above 2 bar,
preferably above 4 bar, more preferably at least to 10 bar. The
desired pressure resistance can be as high as 20 bar or above. One
bar is 100.000 Pascal or 0.1 MPa. Reference can be made to adhesion
to peel, according to ASTM C794.
[0022] Elastic bonding agent, such as glue or adhesive should be
understood as an agent which, after curing, has during use, a high
yield strength and high yield limit. This means it can be stretched
to a relatively high degree before breaking. The elasticity is
preferably such that the yield limit is more than about 300%,
preferably more than about 400%, more preferably more than about
550% and in particular preferably about 650% or more. Preferably
this high yield limit is maintained over the temperature range
during use of the heat exchanger. The yield limit can e.g. be
measured according to ASTM D412.
[0023] The bonding agent can be a silicone or elastomeric based
adhesive, preferably curing at about room temperature to a rubber
like component which is water and gas tight. A bonding layer formed
by said bonding agent is preferably pressure resistant to at least
about 4 Bar, more preferably to about 10 Bar and even more
preferably to about 20 Bar or above, wherein the bonding agent is
preferably applied to unprimed metal of the parts. An example of
such bonding agent is Dow Corning 7091, which has a normal
temperature range of use between -55 and +180.degree. C., and a
yield limit of about 680%.
[0024] All kinds of combinations can be contemplated of yield
limit, pressure resistance and temperature range.
[0025] Dow Corning.RTM. 7091 Adhesive/Sealant is a
high-performance, neutral-cure silicone that cures at room
temperature to a tough, flexible rubber, suitable for the use
described herein. Dow Corning 7091 remains flexible and stable from
-55.degree. to 180.degree. C. (-67.degree. to 356.degree. F.), and
is a one-component, non-sag sealant. It can have a tear strength of
86 ppi and a tensile strength of about 363 psi. This adhesive is
only provided by way of example and should not be considered
limiting the scope in any way.
[0026] By using such a flexible bonding agent parts of the heat
exchanger can be connected to each other, forming fluid, especially
water, and gas tight seals without having to add gaskets, seals or
the like, which will remain fluid and gas tight over a large
temperature range. Moreover, such seals are relatively inexpensive
and are pressure resistant to relatively high pressures.
Furthermore, due to the high flexibility, problems with different
expansion rates and directions of the different parts bonded
together are avoided.
[0027] Alternative or additional to bonding other connecting
techniques and materials could be used, such as but not limited to
welding, screws, nuts and bolts, clamping.
[0028] FIG. 1 shows, schematically in perspective view a heat
exchanger 1 of the present disclosure, comprising a first part 2
and opposite second part 3. In FIG. 2 the two parts 2, 3 of a body
1A of the heat exchanger 1 are shown in side view, in a position in
which they will be connected to each other. As can be seen in this
embodiment the side view the body is substantially Y-shaped, with a
flue duct 4 at a lower first portion 5 and a flame receiving space
6 at an upper second portion 7. The first portion has a width,
especially an average width W1 which is smaller than the average
width W2 of the upper second portion 7. As indicated in FIG. 1 the
heat exchanger, and especially the flue duct 4 and the flame
receiving space 6 have a main direction of flow, indicated by the
arrow 8, extending from an inlet side 9 of the flame receiving
space to an outlet 10 of the flue duct at the opposite side of the
body 1A, in FIGS. 1, 2 and 4 therefore from top to bottom. A flame
receiving space is to be understood as meaning a space in which
during use flames and/or heated flue gasses from a burner 13 are
introduced, wherein the burner 13 can be mounted on or inserted
into the heat exchanger body 1A, especially into said space 6,
and/or be formed at least partly by the body 1A. In FIG. 1 by way
of example a burner 13 is shown having a substantially rectangular,
flat burner face 13A, in a known manner. The overall size of the
burner 13 can be chosen depending on for example the body and the
heat demand/capacity for the heat exchanger and/or a heating system
connected thereto.
[0029] As will be further explained in the flue duct 4 a meandering
flow path is defined for the gas flowing in said main direction 8,
in order to intensify the contact and contact time between the
gasses and the parts 2, 3. To that end each of the parts 2, 3 is
provided with series of ribs 11 extending from an inner wall 12 of
the relevant part 2, 3 in a direction of the opposite part 3, 2.
The ribs 11 each have a length direction L substantially
perpendicular to the main direction of flow 8 and substantially
parallel to the inner wall 12 of the relevant part 2, 3. The ribs
have a height direction H substantially perpendicular to the inner
wall 12 and to the length direction L. In the preferred embodiments
in which the parts 2, 3 have been made by extrusion the length L
direction extends parallel to the extrusion direction, indicated by
the arrow E. Preferably the main direction of flow 8 is also
perpendicular to said extrusion direction E. Some or all of the
ribs may extend substantially perpendicular to said inner wall 12
or some or all may include a different angle with said wall 12.
[0030] In the embodiments shown the first portion 5, which may have
a substantially rectangular side view, comprises a first series of
ribs 11 on each part 2, 3, ribs of one of the parts 2, 3 extending
between ribs 11 of the first series of ribs of the opposite part 3,
2 and vice versa. Thus said meandering flow path is obtained
through the flue duct 4, forcing the gasses to zig-zag through the
duct 4. In a lower part 5A of the first portion 5 the height of the
ribs 11 may be the same, whereas in an upper part 5B of the first
portion the height H may decrease in the direction of the space 6.
Thus in the direction of flow 8 in the gas duct 4 in the upper part
5B, where the temperature of the gas is relatively high, the
available cross section of the flow path will be larger than in the
lower part, wherein the temperature is lower. Thus the heat
exchange between the gasses and the parts 2, 3, especially the ribs
11 can be improved even further.
[0031] It will be understood that especially when the parts are
extruded the ribs will be closed elements having a cross section
perpendicular to the length direction which will be continuous and
the same over the length direction. In the embodiments shown the
cross section is substantially triangular or trapezoid, although
also other shapes and dimensions are possible. They have a base at
the inner wall 12 and a top 11A at the opposite end, wherein the
base 16 preferably is thicker than the top 11A.
[0032] In the upper second portion 7 of the body 1A a second series
of ribs 11 is provided on each part, extending again from an inner
wall part 12A of the first and second parts 2, 3, respectively. As
can be seen the space 6 as such widens in the direction away from
the duct 4, i.e. in a direction opposite to the main flow direction
8, towards the inlet 9. The ribs 11 of the second series have an
increasing height H in the direction of the duct 4, such that the
ribs closest to the inlet 9 are the lowest and the ribs 11 of the
second series furthest from the inlet 9 are the highest, though
preferably still lower than the height of the lowest rib 11 of the
first series. Thus the space 6A between two imaginary planes V
defined by the tops 11A of the ribs 11 of the second series is
widens even more than the space 6 as such. Thus the contact between
the ribs and the gas and/or flames is intensified when entering
further into the body 1A.
[0033] Seen in the main direction of flow 8 of the gasses the
adjacent ribs 11 of the opposite parts in the lower first portion 5
may overlap significantly, for example as much as 50%, 60% or even
75% or more. This means that the flow path of the gasses will force
the gasses to pass close to the bottom portions or base 16 of the
ribs, close to the relevant inner wall 12 to which they are
connected. These bottom portions 16 will provide for the largest
part for heat transfer between the gasses and the ribs.
[0034] In FIG. 4 an alternative embodiment is shown having the same
basis shape and form as shown in FIGS. 1 and 2, but in which the
ribs 11 of the first series, i.e. in the lower first part 5 are
positioned such that pairs of ribs 11 are formed, each comprising a
rib 11 of the first parts 2 and a rib 11 of the opposite second
part 3, having facing top surfaces 11A, which can be flat or can be
formed by a relatively sharp edge or can have any other shape.
Between the top surfaces 11A of each pair a passage 15 is formed
for gas flowing through said duct 4. As can be seen these passages
15 are not directly below each other, that is they are not in a
straight line and thus form a meandering flow path for the gasses
through the duct 4. In the embodiment shown the passages 15 are
alternatingly placed closer to the wall 12 of the one part and to
the wall 12 of the other part 3. Different positioning is obviously
also possible. The cross section of the passages 15 perpendicular
to the main direction of flow 8 may decrease towards the outlet 10,
for example gradually or stepwise, in order to influence the flow
of the gasses through the duct during transfer of heat and thus
cooling of the gasses.
[0035] As can be seen in the embodiments shown the inner wall 12
can be connected to an outer wall 14, for example by a series of
wall parts 17 extending preferably parallel to the ribs 11,
preferably such that the parts 2, 3 can still be integrally
extruded as mono blocks. Between the inner 12 and outer wall 14
water duct sections 18 may be formed, for example enclosed between
said wall parts 17. These sections 18 may be interconnected to form
one or several water ducts 19 extending along the flue duct 4
and/or the flame receiving space 6. These sections 18 can be
connected to each other in the parts 2, 3 and/or by end parts 20,
21 as will be discussed.
[0036] FIG. 3 shows schematically a part of a water duct 19 is
shown, in this case comprising four sections 18, defining a
meandering flow path between a water inlet 22 and a water outlet
23. As shown in FIGS. 1 and 3 in a heat exchanger 1 at two opposite
sides of the body 1A and end part 20, 21 can be provided, closing
off the opposite sides of the flue duct 4, space 6 and sections 18.
These end parts can for example be bonded or glued to the parts 2,
3, thus forming both a solid but sufficiently flexible connection
between the end parts 20, 21 and the parts 2, 3 and forming a
sufficiently flexible and pressure resistant water and gas tight
seal. In FIG. 2 each part 2, 3 comprises 7 such sections 18, in
FIG. 4 nine sections 18. Any number of such sections is however
possible. As can be seen in FIG. 3 of a number of intermediate wall
parts 18 an end part is taken away, for example by milling or
sawing, such that a passage 24 is obtained between the wall part 18
and the adjacent end part 20, 21. Alternatingly these passages 24
are provided close to the first and second end parts 20, 21, such
that the water duct meanders in a zig-zag pattern, providing for a
flow as indicated by the arrows W. Preferably the main direction of
flow of the water is counter flow to the main direction of flow 8
of the gas.
[0037] The first end part 20 in this embodiment comprises an inlet
pipe 25 and an outlet pipe 26, to which in any suitable way
respectively a return line 27 and a feeding line 28 of a heating
circuit 28 can be connected. In the embodiment shown schematically
a circuit 28 for space heating is shown, comprising for example any
number of radiators 29 and a pump 30 for circulating water through
the circuit 28 and the heat exchanger 1. The end part 20 can also
be extruded and the inlet pipe 25 and outlet pipe 26 can be
designed to connect to the water ducts 19 on either side of the
heat exchanger body 1A. Suitable stops can be provided in said
pipes 25, 26, if necessary, to close of an open end thereof.
[0038] In an alternative embodiment one or both of the end parts
20, 21 can be provided with sections for connecting sections 18 of
the water duct 19, of a part 2, 3 and/or of sections between said
parts 2, 3. In the latter case a water duct 19 could be formed
encompassing the circumference of the body 1A, for example
spiraling.
[0039] As can be seen in FIGS. 1 and 2, in some or all of the
sections 18 small ribs 31 or the like can be provided, for
increasing the heat transferring surface.
[0040] A heat exchanger according to the present invention has as
an advantage over the prior art that virtually no machining is
necessary for forming the flue duct 4 and the flame receiving space
6. When extruding the parts 2, 3 only an appropriate length Lb of
the extruded profile has to be cut, after which the body 1A can be
assembled. If a water duct is to be formed as for example shown in
FIG. 3, then only the passages have to be provided for by
machining, resulting in only a very limited loss of material. No
casts, cores or forming tools are necessary. It has moreover been
found that extrusion has the advantage of lower surface roughness
and greater hardness of the surface.
[0041] As can be seen in FIGS. 1 and 4 a closing element 33 can be
provided over the outlet 10, for connecting the heat exchanger to
an exhaust (not shown) and for receiving any condensate from the
flue duct 4, to be disposed off, for example through a condensate
outlet 34.
[0042] A heat exchanger 1 according to the present invention, and
especially the body thereof can be easily manufactured, in a very
economical way, with very limited loss of material. The capacity of
a heat exchanger 1 can easily be adopted by choosing the length Lb
of the body.
[0043] The invention is by no means limited to the embodiments as
shown and/or described in this description. Many variations thereof
are possible within the scope of the claims, including at least all
combinations of parts and elements of the embodiments and parts
thereof shown, in any combination or permutation. For example one
or both of the parts 2, 3 can be made having separate channel parts
above or next to each other for connecting to separate water or
other medium circuits. Moreover the first and/or second parts can
have other cross sections and can for example have further or less
reclining walls, for providing a larger or smaller space 6. The
parts 2m, 3, 20, 21 can be attached to each other using different
means, such as screws, fasteners, clamps, welds or the like. Also
other bonding agents can be used, for example two or more component
agents. Moreover, even thickness of the bonding layers and heat
conducting properties through the connection thus formed can be
achieved by spacers as disclosed in WO2010/098666, or in another
way, for example by gluing tools and moulds used for exact
positioning of the parts during bonding, and/or by providing heat
conducting elements connected to both parts, such as but not
limited to pins, strips or similar, preferably metal elements
inserted in between the bonded parts or to them, crossing said
bonding connection. Shapes and dimensions, as well as positions of
the different parts can be changed within the scope of the claims
as pending. Although extrusion is the favored manufacturing method
for the parts 2, 3, they could also at least in part be made
differently, for example by casting and/or machining. The two parts
2, 3 may be formed as separate parts, preferably mono blocks.
Alternatively they could be formed integrally as one element, in
which case part of a connecting wall between said parts will have
to be removed for forming an inlet and/or outlet 9, 10. Moreover,
more or less channel parts 18 can be provided than shown, in each
of the first and second parts 2, 3, whereas the channel parts,
burner and exhaust can be provided in different positions. For
example, the burner can be positioned partly or entirely inside the
space 6. These and other alterations and modifications are supposed
to be disclosed within the scope of the claims.
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