U.S. patent application number 14/058326 was filed with the patent office on 2014-04-24 for heat exchanger and method for manufacturing such.
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 | 20140110085 14/058326 |
Document ID | / |
Family ID | 47790435 |
Filed Date | 2014-04-24 |
United States Patent
Application |
20140110085 |
Kind Code |
A1 |
DECKERS; Jan Hubertus ; et
al. |
April 24, 2014 |
HEAT EXCHANGER AND METHOD FOR MANUFACTURING SUCH
Abstract
Heat exchanger comprising at least a heat exchanger space, a
burner space and a water conducting channel, wherein the heat
exchanger comprises a body having at least one slot and at least
one cassette insertable into said at least one slot, said cassette
comprising at least part of a water conducting channel.
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: |
47790435 |
Appl. No.: |
14/058326 |
Filed: |
October 21, 2013 |
Current U.S.
Class: |
165/80.1 ;
29/890.03 |
Current CPC
Class: |
F28F 1/022 20130101;
F28D 21/0007 20130101; F28D 9/0081 20130101; F28F 1/40 20130101;
F28F 1/16 20130101; F24H 9/0015 20130101; Y10T 29/4935 20150115;
B21D 53/02 20130101; F28F 13/12 20130101; F28F 2275/14
20130101 |
Class at
Publication: |
165/80.1 ;
29/890.03 |
International
Class: |
F28F 9/00 20060101
F28F009/00; B21D 53/02 20060101 B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2012 |
NL |
2009680 |
Claims
1. Heat exchanger comprising at least a heat exchanger space, a
burner space and a water conducting channel, wherein the heat
exchanger comprises a body having at least one slot and at least
one cassette insertable into said at least one slot, said cassette
comprising at least part of a water conducting channel.
2. Heat exchanger according to claim 1, wherein the at least one
cassette comprises a first wall for engaging a wall of said at
least one slot and a labyrinth forming wall extending from said
first wall, extending between an inlet side and a outlet side of
the cassette.
3. Heat exchanger according to claim 2, wherein the at least one
cassette comprises a first wall and the cassette is open at a side
opposite the first wall and is preferably machined from a metal
element.
4. Heat exchanger according to claim 1, wherein the cassette
comprises a labyrinth which at least partly defines a substantially
zig-zag flow path through the cassette, between an inlet and an
outlet of said cassette.
5. Heat exchanger according to claim 1, comprising a series of such
cassettes, wherein the at least one slot and the cassettes are
designed such that at least two cassettes can be inserted into said
slot, preferably in a side by side relationship.
6. Heat exchanger according to claim 1, wherein the water
conducting channel in said cassette extends between an inlet and an
outlet and has in the flow direction an increasing cross
section.
7. Heat exchanger according to claim 1, wherein the at least one
cassette has been inserted into the at least one slot, wherein the
part of the water conducting channel in the cassette is closed at
least at one side by a wall of the slot.
8. Heat exchanger according to claim 1, wherein a series of
cassettes is provided, each insertable into said at least one slot,
wherein the cassettes comprise different water conducting channel
parts.
9. Heat exchanger according to claim 1, comprising at least two
parts made at least partly by extrusion or casting from light metal
or light metal alloy and/or plastic, said at least two parts
mutually engaging for forming part of the heat exchanging space
and/or the water conducting channel, wherein each of said at least
two parts comprises part of said heat exchanging space and/or said
water conducting channel and wherein the burner space is formed in
one of or between said at least two parts, wherein at least one of
the parts comprises said at least one slot.
10. Heat exchanger according to claim 9, wherein said at least two
parts are connected by an elastic bonding agent, in particular an
elastic glue, forming a bond and a seal, wherein at least the water
conducting channel of the heat exchanger is pressure resistant.
11. Heat exchanger according to claim 1, wherein two end parts are
mounted to the body of the heat exchanger, at opposite sides
thereof, wherein the end parts are preferably bonded to the said
two parts by elastic bonding agent, preferably an elastic glue, at
least partly closing off at least the heat exchanging space and/or
the water channel, and/or wherein said end parts are preferably
made at least partly by extrusion and wherein the at least one slot
is provided in the body and is open to at least one and preferably
both end parts.
12. Series of heat exchangers, each according to claim 1, wherein
at least two heat exchangers in the series are substantially
identical, except for at least one cassette inserted therein.
13. Heat exchanger comprising at least a heat exchanger space and a
water conducting channel, wherein the heat exchanger comprises a
body having at least one slot and at least one cassette insertable
into said at least one slot, said cassette comprising at least part
of a water conducting channel, wherein the at least one slot is
enclosed in a wall portion of the heat exchanger, separated from
the at least one heat exchanger space.
14. Heat exchanger according to claim 13, wherein the at least one
cassette comprises a first wall for engaging a wall of said at
least one slot and elements extending from said first wall.
15. Heat exchanger according to claim 13, wherein the at least one
cassette comprises a first wall and the cassette is open at a side
opposite the first wall.
16. Heat exchanger according to claim 13, wherein the cassette is
made using machining.
17. Heat exchanger according to claim 13, wherein the cassette
comprises a labyrinth which at least partly defines a substantially
zig-zag flow path through the cassette, between an inlet and an
outlet of said cassette.
18. Heat exchanger according to claim 13, comprising a series of
such cassettes, wherein the at least one slot and the cassettes are
designed such that at least two cassettes can be inserted into said
slot.
19. Heat exchanger according to claim 18, wherein the cassettes can
be inserted into the at least one slot in a side by side
relationship.
20. Heat exchanger according to claim 13, wherein the at least one
cassette has been inserted into the at least one slot, wherein the
part of the water conducting channel in the cassette is closed at
least at one side by a wall of the slot.
21. Heat exchanger according to claim 13, wherein a series of
cassettes is provided, each insertable into said at least one slot,
wherein the cassettes comprise different water conducting channel
parts.
22. Heat exchanger according to claim 13, comprising at least two
parts made at least partly by extrusion or casting from light metal
or light metal alloy and/or plastic, said at least two parts
mutually engaging for forming part of the heat exchanging space
and/or the water conducting channel, wherein each of said at least
two parts comprises part of said heat exchanging space and/or said
water conducting channel and wherein the burner space is formed in
one of or between said at least two parts, wherein at least one of
the parts comprises said at least one slot.
23. Heat exchanger according to claim 22, wherein said at least two
parts are connected by an elastic bonding agent forming a bond and
a seal, wherein at least the water conducting channel of the heat
exchanger is pressure resistant.
24. Heat exchanger according to claim 23, wherein the bonding agent
is an elastic glue, forming a bond and a seal.
25. Heat exchanger according to claim 13, wherein two end parts are
mounted to the body of the heat exchanger, at opposite sides
thereof, wherein the end parts are connected to said two parts, at
least partly closing off at least the heat exchanging space and/or
the water channel, and/or wherein said end parts are made at least
partly by extrusion and wherein the at least one slot is provided
in the body and is open to at least one end part.
26. Heat exchanger according to claim 25, wherein the at least one
slot is open to both end parts.
27. Heat exchanger according to claim 13, wherein further a burner
space is provided, part of or connecting to the heat exchanging
space in the heat exchanger, separated from the at least one
slot.
28. Method for manufacturing a heat exchanger or parts thereof,
comprising the steps of: forming a heat exchanger body provided
with at least part of a heat conducting space and a slot extending
in a first direction of said body; forming at least one cassette
provided with a water conducting channel part; inserting the at
least one cassette into said at least one slot, forming a water
conducting channel through said body, preferably between two
opposite ends thereof.
29. Method according to claim 28, wherein the body is formed using
one or more extruded or cast elements and wherein the at least one
cassette is formed by machining metal, such that a cassette is
formed having a first wall and channel defining walls extending
from said first wall, forming a labyrinth shaped water channel
part, open at a side opposite the first wall, wherein the at least
one slot is made such that when the cassette is inserted into said
slot, said at least one open side is closed substantially by a wall
of the slot.
30. Method according to claim 28, wherein a slot is provided on
either side of the heat conducting space, wherein in each slot at
least one cassette is provided, water conducting channel parts in
the cassettes being interconnected.
31. Method according to claim 28, wherein a further cassette is
inserted into the heat conducting space, said further cassette
provided with at least one gas flow channel.
32. Heating apparatus comprising a heat exchanger according to
claim 1.
33. Heating apparatus comprising a heat exchanger made with a
method according to claim 28.
Description
[0001] The invention relates to a heat exchanger and a method for
manufacturing such.
[0002] Heat exchangers are used in heating apparatus such as
central heating heaters, boilers and the like. In such heat
exchangers a burner is provided, fired by for example gas or oil.
Heat generated by the flames extending from the burner is exchanged
between heated gas and heat exchanging surface of the heat
exchanger, from which it is in turn transferred to a fluidum
provided in channels or spaces within the heat exchanger, such as
water for central heating, air or water for household use. In such
heat exchangers pressure is build up during use, at elevated
temperatures. This provides for special requirements with respect
to sealing of such heat exchangers. In such heat exchangers
especially flow paths for water and heated gasses have to be well
defined in order to obtain an optimal heat transfer from the heated
gasses to water flowing through the water duct or ducts.
[0003] A problem of known methods for manufacturing heat exchangers
is that for different capacities, flow resistance or flow paths of
or in the heat exchangers different moulds are necessary. This
means that large investments are necessary for series of such heat
exchangers, for the necessary tooling.
[0004] EP2401571 discloses a heat exchanger having a burner space
connected to a heat exchanging space and at least one water duct,
the water duct being in heat conducting relation to a wall of the
heat exchanging space. In this known heat exchanger the water ducts
are at least partly extruded with the body of the heat exchanger or
at least parts thereof, limiting the freedom for designing these
water ducts. Moreover machining of the extruded body or body part
may be necessary, whereas side closing elements are necessary for
closing of opposite sides of the water duct.
[0005] DE102005010508 discloses a heat exchanger comprising two
cast part, together enclosing a burner space and a flue gas
channel. Water channels extend around the flue gas channel,
integrated in the cast parts. Heat exchanging surface increasing
elements in the form of pins extending from a front or rear wall,
perpendicular to a main direction of flow of gas through the flue
gas channel are provided inside the flue gas channel. Each cast
part comprises integral partitioning walls extending from a side of
the front or rear wall opposite the pins, defining water channel
parts. In two side walls water ducts are integrally formed,
connecting the water channel parts of the two cast parts, for
forming one water channel extending around the flue gas channel. In
the direction of flow the water channel has a decreasing cross
section. A lid can be placed over the partitioning walls and water
channel parts formed there between, for closing off the water
channel parts.
[0006] WO2010/098666 discloses a heat exchanger comprising at least
a heat exchanger space, a burner space and a water conducting
channel. The heat exchanger comprises a body having at least one
slot separated from the heat exchanger space and/or the burner
space by a wall of the slot. In WO2010/098666 several such slots
can be provided, each slot forming part of the water conducting
channel. Each of these slots has a straight configuration, defined
by two parallel walls and two separating walls interconnecting said
parallel walls. One of the parallel walls separates the slot from
the burner space and/or the heat exchanger space through which flue
gas flows during use. Water can flow unobstructed through said
slots.
[0007] EP0789203 discloses a heat exchanger comprising a series of
modules, each having a burner space on a first side of a separating
wall and a water channel at an opposite side thereof. Each module
is formed as an integral part to be connected to an identical part.
At least part of the water is fed from a central inlet pipe
directly to the area of the burner space and from there towards a
central outlet pipe. At opposite ends of such series of modules
lids or end parts will be provided closing off the water
channels.
[0008] One aim of the present invention can be to provide
relatively inexpensive heat exchangers for heating systems,
comprising a burner for creating heated flue gasses in the heat
exchanger and feeding these into a heating space of said heat
exchanger. Another aim can be to provide a method for manufacturing
such heat exchangers or parts thereof, which is relatively
inexpensive, especially compared to known methods. A still other
aim can be to provide a method for manufacturing series of such
heat exchangers having different capacities and/or characteristics.
At least one of these aims can be achieved by a heat exchanger or a
method according to the present invention. These aims are not
mentioned in any relevant order or decisive for the present
invention over the prior art.
[0009] In a first aspect a heat exchanger according to the present
description can be defined by comprising at least a heat exchanger
space, a burner space and a water conducting channel. The heat
exchanger comprises a body having at least one slot and at least
one cassette insertable into said at least one slot, said cassette
comprising at least part of a water conducting channel.
[0010] In another aspect a method according to the present
description can be defined by a method for manufacturing a heat
exchanger or parts thereof comprising the steps of: [0011] forming
a heat exchanger body provided with at least part of a heat
conducting space and a slot extending in a first direction of said
body; [0012] forming at least one cassette provided with a water
conducting channel part; [0013] inserting the at least one cassette
into said at least one slot, forming a water conducting channel
through said body, preferably between two opposite ends thereof.
These steps do not have to be performed in this order.
[0014] In embodiments at least two parts for forming at least part
of the body are extruded or cast. The parts can then for example
subsequently be connected, for example elastically bonded to each
other for forming a fluid space. If any part is extruded,
preferably between extruding and bonding the parts at least one of
the parts is machined by removing at least part of heat exchanging
surface enhancing elements integrally extruded in the parts, for
forming at least part of a burner space and/or a part of a heat
exchanging space.
[0015] From EP1707896 an auxiliary heat exchanger is known,
comprising a box shaped part 10 comprising a water channel,
extending between an inlet and a directly adjacent outlet. The box
shaped part has two opposite, parallel closed side walls having a
relatively large surface area compared to the thickness of the box
shaped part between said side walls. The auxiliary heat exchanger
further comprises an outer casing 11, again substantially box
shaped, with two parallel side surfaces, a top and bottom surface
and a rear surface. A side opposite the rear surface is
substantially open. Baffles extend from an interior side of the
side surfaces for forming flue gas channel parts. Between facing
edges of the baffles extending from opposite side surfaces a space
is left, such that the outer casing can be fit over the box shaped
part 10 comprising the water channel. A flue gas inlet and flue gas
outlet are provided on the top surface. A lid can be connected to
the box shaped part 10 for closing the front side of the outer
casing when the box shaped part is positioned between said baffles.
The said free edges of the baffles are said to be close to the side
surfaces of the box shaped part.
[0016] During use the inlet of the water channel is connected to an
outlet end of a heating circuit, whereas the outlet of the water
channel is connected to an inlet of a water channel in a heating
boiler having a burner. The flue duct is connected between a flue
gas outlet of said heating boiler and a chimney. Thus flue gas
cooled inside the heating boiler can be cooled further in the
auxiliary heat exchanger of EP1707896, by pre-heating water flowing
from a heating circuit prior to feeding it to the heating boiler.
Since the space within the outer casing is provided between the
free edges of the baffles, the space in the outer casing is
entirely open once the outer casing has been removed from the box
shaped part comprising the water channel. Thus the flue gas channel
in the outer casing and the outside of the box shaped part can
easily be cleaned, whereas the outer casing can easily be removed
without having to disconnect the water channel from the heating
circuit and heating boiler. The auxiliary heat exchanger of
EP1707896 does not have a burner and is operated at relatively low
temperatures for the flue gasses and water flowing through it
compared to a heat exchanger of a heating boiler with a burner as
known from e.g. WO2010/098666 or EP0789203.
[0017] The present invention shall be further elucidated in the
following description, with reference to the drawings, in
which:
[0018] FIG. 1 shows a heat exchanger, schematically, in perspective
view;
[0019] FIG. 2 in perspective view a part of a heat exchanger, shown
generally from a first side;
[0020] FIG. 3 in perspective view a part of a heat exchanger, shown
generally from an opposite side;
[0021] FIG. 4 a partly assembled heat exchanger from a first
end;
[0022] FIG. 5 a first part of a heat exchanger in a side view;
[0023] FIG. 6 a second part of a heat exchanger in a side view;
[0024] FIG. 7 in perspective view a partly assembled heat exchanger
from a second side;
[0025] FIG. 8 a heat exchanger of FIG. 7, with a mounted end
plate;
[0026] FIG. 9 a heat exchanger of FIGS. 7 and 8, from an opposite
end;
[0027] FIG. 10 schematically a gas flow path of a heat exchanger
according to the present disclosure;
[0028] FIG. 11 schematically a water flow path of a heat exchanger
according to the present disclosure;
[0029] FIG. 12 in perspective view schematically and enlarged part
of a heat exchanger part;
[0030] FIGS. 13A and B in frontal and side view a part of a heat
exchanger part, in further detail;
[0031] FIGS. 14A and B in side view connecting parts of a heat
exchanger part, in further detail
[0032] FIG. 15 in perspective view a heat exchanger, partly open
and with a cassette partly inserted into the heat exchanger;
[0033] FIG. 16 in perspective view a heat exchanger, with a
cassette partly inserted into the heat exchanger; and
[0034] FIG. 17 schematically a cassette for inserting into a heat
exchanger.
[0035] 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 has 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 burner space is provided 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.
[0036] 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.
Parts of heat exchangers according to this disclosure can be made
differently, for example by pressing, setting, folding, welding or
any other suitable means known to skilled person.
[0037] In this disclosure embodiments of heat exchangers shall be
disclosed by way of example only. In general terms an element of
the present disclosure is that in a heat exchanger for exchanging
heat between flue gas and a second medium, preferably a to be
heated medium, such as but not limited to water, at least part of a
water conducting channel is enclosed in or formed by a cassette,
which can be placed inside a slot in a heat exchanger body. The
heat exchanger body can in embodiments be made at least partly by
extrusion, such that the at least one sot into which a cassette can
be provided can be formed during such extrusion. However, also
other embodiments can be provided for example cast heat exchanger
bodies, or slots extending in different directions. Slots can be
open or closed, can be single or multiple in a heat exchanger, and
slots can be provided for receiving a single cassette or several
such cassettes.
[0038] In this disclosure a cassette is to be understood at least
as meaning an element insertable into slot in a heat exchanger. A
cassette can be closed except for an inlet and outlet, or can be
open at at least one side, such that for example at least part of a
wall of the slot into which it is inserted and/or part of another
such cassette can close said cassette or at least part of a fluid
duct, especially a water duct enclosed therein and/or formed
thereby. Closed off has to be understood as at least including
meaning closing it such that the fluid channel or duct is fully
enclosed within the cassette, substantially only fluidly
communicating with the environment of the cassette through one or
more inlets and one or more outlets of the channel or duct.
[0039] In FIG. 1 schematically a heat exchanger 1 is shown, in
perspective view, generally from a second side. This heat exchanger
1 comprises a first part 2, a second part 3, a first end part 4 and
a second end part 5. In a heat exchanger 1 according to this
description at least one of the first and second parts 2, 3 and/or
the first and second end parts 4, 5 can be made at least partly by
extrusion. At least one of these parts 2, 3, 4, 5 is preferably
made of light metal, such as aluminium, aluminium alloy, magnesium,
magnesium alloy, or other metal. Preferably all parts 2, 3, 4, 5
are made at least partly by extrusion and at least partly of metal,
preferably light metal.
[0040] In the embodiments shown at least two of the first 2 and
second part 3 and the first 4 and second end part 5 can be mutually
connected together for forming at least one of a gas flow space 6
and a water flow space 7. The gas space 6 and water flow space 7
can for example comprise one or more channels. In the embodiment of
FIG. 1 the second end part 5 comprises a first and second channel
part 8A, 8B, both having a length direction L.sub.8. The length
directions L.sub.8 are in this embodiment parallel, such that the
end part 5 can be extruded in the length direction L.sub.8. In each
of the channel parts 8A, 8B an opening 9A, 9B is provided, for
example by drilling. Screw treads can be provided in the openings
9A, 9B in order to connect piping to these openings, as will be
discussed later on. The parts can be connected mutually by bonding
or welding. Alternatively and/or additionally the parts can be
interconnected mechanically for example by screws, bolts, clamps,
press fittings or the like means, in which case at least preferably
appropriate seals are used.
[0041] 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.
[0042] 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.
[0043] 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%.
[0044] All kinds of combinations can be contemplated of yield
limit, pressure resistance and temperature range.
[0045] 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.
[0046] 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.
[0047] FIG. 2 shown in perspective view a first part 2. This part 2
can be made substantially be extrusion. The part 2 shows a first
wall 10 and two second walls 11A, B. The first wall 10 is a
substantially hollow wall, defined by a first wall part 10A and a
second wall part 10B, for example extending substantially parallel
to each other, whereas a number of cross walls 12 extend between
the first and second wall parts 10A, 10B. Between the walls 10A,
10B and the walls 12 a series of slots 60 is formed. In this
embodiment the slots 60 are open to two longitudinal ends 61A, 61B
and extend parallel to each other, preferably in an extrusion
direction of the part 2.
[0048] The second walls 11A, B extend at an angle .alpha. to the
first wall 10. The angle .alpha. differs from 180 degrees. The
angle .alpha. is for example between 45 and 135 degrees and is
preferably about 90 degrees. The walls 11A, B extend in a first
direction from the first wall 10. One or more of the second walls
11A can be lower than at least one other wall 11B of the second
walls 11. On the first side of the first wall 10 an intermediate
wall 13 extends, in the same direction as the second walls 11.
Between each of the second walls 11A, B and the intermediate wall
13 a series of fins 14 is provided, extending in the same first
direction from the first wall 10. The fins 14 can form heat
exchanging surface increasing elements. As shown in FIG. 2 the
second walls 11, the intermediate wall 13, the cross walls 12 and
the fins 14 all have a length direction X and thus extend
substantially parallel to each other. The free ends 15 of the
second walls 11 and the intermediate wall 13 can have a groove 16
extending in the said length direction X, open to a side facing
away from the first wall 10.
[0049] As is shown in FIG. 2 to the right side of the intermediate
wall 13 the fins 14 can have a reclining end 17, such that the fins
14 have a greater length XA near the first wall 10 than the length
XB at the opposite free side 15 thereof. The opposite end 18 of the
fins can be straight, such that the second ends 18 of the fins 14
form a substantially flat plane V extending substantially
perpendicular to the first wall 10, for example at a distance B
from the opposite edge 20. These fins 14 can end at a distance A
from the edge 19 of the first wall 10. The intermediate wall 13
extends from the edge 19 to a distance B from the opposite edge 20
of the first wall 10. The reclining ends 17 can in an alternative
also be e.g. convex or concave. The space created thereby can be
narrowing in the direction of the edge 20. Obviously the reclining
ends can also be substantially or partly convex of concave or have
another regular or irregular shape, providing said effect of a
narrowing burner chamber 30
[0050] As is shown in FIG. 2 to the left side of the intermediate
wall 13 the fins 14 can have a straight end 21, such that the fins
14 have about the same length XC near the first wall 10 as at the
opposite free side 15 thereof. The opposite end 22 of the fins can
be straight, such that the second ends 22 of the fins 14 abut the
same substantially flat plane V extending substantially
perpendicular to the first wall 10. Some of the fins 14, positioned
next to the intermediate wall 13 can end at a distance C from the
edge 19 of the first wall 10. The further fins 14 can extend the
full length X of the first wall 10.
[0051] At two opposite outer sides of the second walls 11A, B a
profile 23 is provided, having a substantially circular inner cross
section. At the base of the intermediate wall 13 a further opening
23A can be provided, extending all the way through the relevant
part 2, 3.
[0052] This first part 2 can be made by extruding a continuous
length of profile having a cross section as for example shown in
FIG. 5. A desired length X.sub.1 can be sawn off from the
continuous length. Then part of the first ends 17 of the fins 14
can be removed, for example milled or sawn off, as can the second
end of the intermediate wall 13. Because of the open side of the
parts this is easily accessible for such machining. In the
embodiment shown five cross walls 12 are shown, dividing the space
24 within the double first wall 10 into four parallel channel parts
24A, 24B, 24C, 24D forming essentially the slots 60. Different
numbers of channels or slots 60 can be used. The two middle channel
parts 24B, C are connected to each other by removing part of the
first end 25 of the cross wall 12 in between, whereas the left hand
two channel parts 24A, 24B in FIG. 2 are connected to each other by
removing part of the second end 26 of the intermediate cross wall
12, adjacent the plane V. In a similar manner part of the second
end 26 of the cross wall 12 between the right hand two channel
parts 24C, 24D can be removed to connect these two channel parts
24C, 24D. Inside the slots 60 formed by the channel parts 24
cassettes 62 can extend which form part of a water conducting
channel 6 as will be further discussed.
[0053] FIG. 3 shows the first part 2 as shown in FIG. 2, from the
opposite second side. Here clearly the second ends of the fins 14
and the second walls 11 and intermediate wall 13 can be clearly
seen, forming a plane Ve, parallel to the plane V. Planes V and Ve
are imaginary planes.
[0054] Between the fins 14 and between the walls 11, 13 and
adjacent fins 14 spaces are provided, such that a substantially
regular pattern can be formed. The second part 3 can be formed in a
similar way.
[0055] In embodiments at the free ends of the walls 10 and 11, at
opposite ends seen in the length direction X.sub.C, bonding
surfaces B.sub.1 and B.sub.2 respectively can be formed. These
bonding surfaces are preferably flat and even. As is schematically
shown in e.g. FIGS. 3-7 and further and in larger detail shown in
FIGS. 12 and 13, these bonding surfaces can be provided with spacer
elements 52. These spacer elements 52 can be integral part of the
parts 2 and/or 3 and/or of end parts 4 and/or 5. The spacer
elements can be small elevations above the bonding surfaces B,
which can be provided by machining of said surfaces B, for example
milling. In another embodiment these spacer elements 52 can be
provided in or on the surface separately and e.g. be glued or
screwed in place. The spacer element extent to a relatively short
distance d.sub.1 above said bonding surface B, for defining a
thickness t.sub.1 of the bonding layer 53, as is shown in FIG. 13B.
In FIG. 12 a perspective view of a part of a first or second part
2, 3 or of an end part 4, 5 is shown, in enlarged view, showing a
substantially cylindrical spacer element 52. Obviously these spacer
elements 52 can have any desired shape or form, and a height
d.sub.1 depending on the desired, optimal thickness t.sub.1.
[0056] In FIG. 14A shows in side view a ridge 27 on a wall 11, 13
of a second part, by way of example only, whereas to the side of
said ridge 27 shoulders 54 are formed, as part of the wall 11, 13
having a larger width than the ridge 27. On each shoulder, or on
only one if desired, at least one spacer element 52 is provided,
again having a relatively low height d.sub.1 above the surface of
the shoulder 54. This can for example be a ridge extending over a
length of said wall 11, 13, or one or more shorter elements, such
as for example pins, ribs or the like. In FIG. 14B such spacer
elements 52 are shown on the end surface of the wall 11, to the
sides of the groove 16. Again the height d.sub.1 is relatively
small. Similar elements can be provided on top of the ridge 27, to
the sides thereof and/or at the bottom 56 of the groove 16. In FIG.
14 B the bonding layer 55 is sketched in by phantom lines, as an
indication. Preferably the space between the ridge 27 and the inner
wall of the groove 16 has a width t.sub.1 similar to the height
d.sub.1 of the spacer elements 52. The
[0057] The spacer elements 52 have the advantage that they define
the minimum space between two opposite bonding surfaces B of for
example the first and second parts 2, 3 and/or the end parts 4, 5,
thus defining the thickness t of the layer of bonding agent, and
more specifically defining an even thickness thereof over the
entire relevant surface B, or between the ridge 27 and the groove
16 cooperating therewith. This means that the optimal amount of
glue can be used, reducing costs, whereas the best bonding and
sealing can be obtained easily with the relevant bonding agent.
This is obtained by at least one bonding surface B abutting the
spacer elements 52 on the at least one other bonding surface it is
to be bonded with, preventing it from being pressed closer to said
bonding surface. The height of the spacer elements 52 above the
relevant bonding surface B can be in the order of tenth's of
millimetres or less, e.g. between 0.01 and 1.5 mm, preferably less
than 1 mm. Obviously the height and thus the thickness of the layer
can be chosen dependent on the characteristics of the bonding agent
used, for optimisation. By minimizing the thickness of the layer of
bonding agent 55, the transfer of heat between the parts bonded
together will be maintained. Moreover, due to the fact that one of
the parts will be in direct contact with the or each other part it
is bonded to by the abutting contact between the bonding surface of
one of said parts with spacer elements on another bonding surface
it is bonded too, there will be direct metal to metal transfer of
heat, which will further optimize the heat transfer.
[0058] In FIG. 4 a partly assembled heat exchanger 1 is shown, in
side view, in which at least a first 2 and second part 3 are shown,
assembled. In FIGS. 5 and 6 respectively the first part 2 and the
second part 3 are shown, equally in side view. As can be seen the
second part 3 has a cross section similar to that of the first
part, but the second walls 11C, 11D and the intermediate wall 13B
have heights such that when positioned on the second walls 11A, 11B
and 13 respectively, the first wall 10 of the first part 2 extends
parallel to the first part 10 of the second part 3, thus forming a
substantially rectangular cross section. The second walls 11C, 11B
and the intermediate wall 13 of the second part 3 have ridges 27
that can fit in the grooves 16. The fins 14 of the first part 2 can
extend between the fins 14 of the second part and/or between a fin
and either a second wall 11C, D or the intermediate wall 13 of the
second part. The fins 14 can have a substantially triangular or
trapezoid cross section with a base 28 near the respective first
wall 10 broader than the free side thereof.
[0059] As can be seen the channel parts 24 of the first walls 10
can have a ribbed or otherwise corrugated or channelled surface, at
least at the side of the fins 14, in order to increase the heat
exchanging surface of the channel parts 24. In other embodiments
these sides of the channel parts 24 can be flat, that is without
such ribs. Heat of the fins 14 can be transferred to water in the
cassettes 62 inserted in the channel parts 24 through the first
wall 10.
[0060] The first part 2 is bonded to the second part 3, by bonding
the second walls 11A, B of the first part 2 to the second walls
11C, D of the second parts 3. The intermediate wall 13 of the first
part 2 can also be bonded to the intermediate wall 13 of the second
part 3. Preferably at least the ridges 27 can be bonded in the
grooves 16. Bonding can be achieved by glue, for example acrylic
glue, two or more component glue, PLEXUS MA 420, PERMABOND ES 550
or DOW CORNING 7091. As can be seen in FIG. 4 preferably the
grooves can have an open side having a width slightly less than the
adjacent part of the groove 16, whereas the ridge 27 can have a
width substantially similar to the width of the open side. This
means that glue in the groove 16 will be locked in the groove by
forcing the ridge 27 into the groove 16, whereas the ridge 27 will
be centred within the groove 16, when the opening is provided
symmetrically. The space between the ridge 27 and the walls of the
groove 16 is preferably similar in width to the height of the
spacer elements 52, such that a layer of bonding agent can be
formed between said ridge 27 and groove 16 similar in thickness as
that between the bonding surfaces as discussed before.
[0061] When an embodiment of a ridge 27 and/or groove 16 is used as
disclosed in FIGS. 14A and B, spacer elements 52 can again be used
for defining the thickness of a layer of bonding agent.
[0062] As can be seen in the various figures, the spacer elements
52 can be distributed over all or some of the bonding surfaces B
and/or end parts 4, 5. Preferably they can at least be provided on
first walls 10 near partition walls 12 and near walls 11 and 13, as
well as on the walls 11 and 13. Moreover they can be provided for
example at feet 50. Preferably they are distributed such that
pressure applied to the parts and, especially, the parts 4, 5 does
not significantly bend or otherwise deform any surface in between
the spacer elements 52. The spacer elements 52 are preferably
provided at a short distance from a or, more preferably, at a
distance from each of the sides of the relevant bonding surface
they are provided on. This has the advantage that the bonding agent
can surround the spacer element 52 at least partly within the layer
of bonding material, or at least form a continuous seal between the
bonding surfaces B alongside the spacer elements, and preferably
can surround the spacer elements 52 entirely, for forming both a
good adhesion between the bonded parts and a good sealing. Again,
the direct contact between the metal parts through the spacer
elements will improve the heat transfer between parts. The
relatively small thickness of the bonding layer 55 will furthermore
prevent thermal isolation further. Moreover this prevents too
flexible seals.
[0063] FIG. 7 shows a partly assembled heat exchanger 1, open at
the first side, showing the second walls 11A, C and 11B, D bonded
to each other, as well as the intermediate walls 13. Between the
first walls 10 and the second walls 11 of the first and second
parts 2, 3 a heat exchanging space 30 is defined, at least partly.
At two opposite sides of the space 30 in the respective first wall
10 at least one cassette 62 and preferably a series of cassettes 62
is provided in the channel parts 24 for forming part of a duct 6
for e.g. water. A second end part 5 is partly visible at the second
side of the heat exchanger 1. At the first side the fins 14 are
visible. At one side of the intermediate walls 13 the reclining
ends 17 of the fins 14 are shown. Between the edge 19 and the ends
17 of the fins 14 a burner space 31 is provided. In the burner
space 31 a burner can extend at least partly or, when a burner is
used which is provided outside said space 31, then flames can
extend into the space. The reclining ends 17 are provided to
prevent undesired tension in the fins 17. At the opposite side of
the intermediate walls 13 a space 32 can be provided, in order to
reduce flow resistance and improve the heat exchange between heated
gas flowing through the space 30 between the fins 14 and/or the
fins and the walls 11, 13.
[0064] In FIG. 8 a heat exchanger 1 is shown, similarly to FIG. 7,
but with a first end part 4 at the first side of the heat exchanger
1. The first end part 4 can be bonded, such as glued to the first
and second parts 2, 3. Similarly the second end part 5 can be
bonded, such as glued to the second side of the heat exchanger 1.
Again spacer elements 52 can be used for defining the optimal or at
least desired thickness of the layer of bonding agent. In the first
end part 5 a first opening 33 is provided, opening into the burner
space 31. A second opening 34 is provided, opening into the space
32. In and/or over the first opening 33 a burner 34 can be
positioned, as is shown in FIG. 10. In and/or over the second
opening a gas exhaust 35 can be connected, as is shown in FIG.
10.
[0065] As can be seen in FIGS. 8 and 9 in an embodiment the
channels 8A, B can extend beyond the periphery of the first and
second parts 2, 3. In the embodiment of FIGS. 8 and 9 the channels
parts 8A, b extend in opposite directions beyond the periphery. In
each of the extending portions 35A, 35B an opening 9 is provided,
for example by drilling or milling, preferably provided with
internal screw threads or another means for attaching a pipe of a
heating circuit. An inlet of a heating circuit can be connected to
one of the openings 9, an outlet of the heating circuit to the
other opening 9. The openings 9 are preferably provided in a wall
38 of the channels facing in the direction of the first and second
part 2, 3 of the heat exchanger 1. This can provide a compact heat
exchanger and easy access. The open ends 36 of the channels parts
8A, B can be closed off by stops 37, as is shown in FIG. 1. The
stops can also be bonded such as glued. In the wall 38 of each of
the channel parts 8A, B at least one further opening 51 is
provided, opening into a channel part 24 inside a first wall 10,
for fluidly connecting the channel part 24 with the channel part 8
and thus with the relevant opening 9. In the embodiments of FIGS. 1
and 8 one channel part 8A is connected to a first channel part 24A,
and thus to a cassette 62 inserted into such channel part 24A of
each of the first walls 10, whereas the other channel part 8B is
connected to the last channel part 24D, and thus to a cassette 62
inserted into such channel part 24D of the first wall. In the
embodiments shown this is the fourth channel part 24D but obviously
other numbers of channel parts can be provided, whereas the channel
parts 8A, B or further such channel parts 8 can be connected to
other channel parts 24 or even to each of the channel parts 24,
and/or to cassettes 62 provided therein, depending on the desired
flow paths of the water through the walls 10.
[0066] The first and/or second end parts 4, 5 can basically be made
by extrusion, the extrusion direction in the length direction
L.sub.8 of the channel parts 8A, B. For an embodiment of for
example FIGS. 8 and 9 parts of the wall 38 can be removed, for
example by milling or sawing, to provide for the extending portions
35A, B. Openings 9 can be provided then by for example drilling or
milling. The end parts can be bonded, such as glued, to the first
and second parts 2, 3. The end parts 4, 5 can be provided with
further openings 39. When assembling the heat exchanger bolts or
rod with ends provided with screw threads can be inserted through
these openings 39 and the channels 23 or openings 23A extending
there behind, after which nuts can be screwed onto the bolts or
screw thread of the rods, in order to further clamp the end parts
4, 5 to the first and second parts 2, 3. This can provide for
further mechanical strength.
[0067] In FIG. 10 schematically a gas flow path is shown, thorough
the inner space 30 of a heat exchanger 1, between the burner 34 and
the exhaust 35. As can be seen gas, heated by the burner 34 can
flow, as indicated by arrows G from the burner space 31 in which
part of the burner 34 extends and during use flames are provided by
the burner 34, into the spaces between the fins 14 and/or fins and
adjacent walls 11, 13. At the second side opposite the burner 34
the gas can flow between the end part 5 and the end 19 of the
intermediate wall 13, in to the spaces between the fins 14 in the
space between the second end part 5 and the exhaust 35. From there
the gasses can flow into the exhaust 35 to be expelled. A
condensate drain 40 can be provided in or next to the exhaust
35.
[0068] As can be seen in FIG. 10 in this embodiment the length of
the fins 14 in the space between the second end part 5 and the
exhaust can vary, such that the fins closest to the intermediate
wall 13 are longer then fins closer to the second wall 11B and the
space 32 has a substantially trapezoid shape. This has the
advantage that all gasses flowing through the space 30 have about
the same contact with fins, independent of their flow path.
[0069] In FIG. 11 schematically a water flow path is shown through
the first walls 10 and the channel parts 8A, B. In this embodiment
water is provided to the heat exchanger 1 through an inlet 41 into
the channel part 8A. The inlet 41 is shown as a pipe 42 extending
from a heating circuit 43, schematically shown in FIG. 11 as having
a pump 44 and a radiator 45, and connected to the relevant opening
9. In other embodiments this can for example be a household water
or sanitary water supply, a boiler, or other means using heated
water or other heated fluids or gasses. The water flowing from the
inlet 41 flows into the channel part 8A and is divided over both
channels 24, and thus cassettes 62 in the respective first and
second part 2, 3. In FIG. 11 only one of these channels 24 formed
by or at least containing the slots 60 housing the cassettes 62 is
shown. The water then flows through the cassettes 62 provided in
the channel parts 24 A-D, to the other 8B of the two channel parts
8 as is shown by arrows W, through which the water from both
channels 24 and the cassettes 62 provided therein can flow into an
outlet 45, here shown as a pipe 46 connected to the heating circuit
43. Thus heat can be exchanged between the gasses flowing through
the space 30 and the fins and walls, especially walls 13 and 10,
which heat can then be transferred to water or other medium flowing
through the channels 24 and especially the cassettes 62 therein, to
be used in the heating circuit 43. The flow through the channels 24
and especially the cassettes 62 and the space 30 if preferably such
that water and gas have counter flow directions as much as
possible. This can for example be obtained by positioning the inlet
41 in the second end part 5 at the exhaust 35 side of the
intermediate wall 13, the outlet 45 being provided on the opposite
side of the intermediate wall 13, in the second end part 5.
[0070] Obviously in FIG. 11 the arrows W indicate a general
direction of flow of water through a relevant slot, whereas the
actual flow of water may be defined by the partitioning walls 67,
defining a zig-zag or meandering flow path for the water through
one, some or all of the slots. The slots are formed as spaces
separated from the flue gas channel by a common wall integral to
the body of the heat exchanger, such that the slot itself can
define a water channel part and/or a cassette inserted therein.
Moreover, the or each slot enclosed in a wall of a heat exchanger
part has the advantage that even if the heat exchanger part may
expand slightly, due to the relatively high temperatures, the slot
will remain being separated form the flue gas channel and burner
space, whereas the flue gas channel and burner space also remain
closed to the surrounding, the flow path of the flue gas remaining
well defined.
[0071] As will be understood the bonding agent such as glue used
for bonding different parts of the heat exchanger 1 to each other
preferably provides a sealing between these parts too, which
provides for a water and gas tight connection without the necessity
of further sealing means such as seals. In other embodiments
sealing of at least some of the parts relative to each other can be
obtained through other means, such as seals, gaskets or the like
sealing means. By using an elastic bonding agent for connecting and
sealing parts of the heat exchanger, the surprising advantage is
obtained of lower cost, and better sealing than when a hard or
hardening agent is used. Moreover, due to the bonding, especially
in combination with spacer elements, the connection can be made
strong and gas and fluid tight, as well as pressure resistant.
[0072] A heat exchanger 1 according to the present invention is
relatively easy to produce, is economical in comparison to heat
exchangers having the same capacity made by for example moulding or
welding, and can easily be adapted for example different
capacities, set up such as amendment of the position of the inlet
and/or outlet 41, 45, the burner 34 and the layout of the channels
24 and fins 14. Moreover, a range of heat exchangers 1 can be
provided, differing basically only in the length X.sub.1 of the
first and second part 2, 3. These different heat exchangers will
have different capacities, depending on and mainly in relation to
the length X.sub.1. This means that with the same extrusion tools
different heat exchangers can be made, reducing production costs.
Moreover, by using cassettes 62 as disclosed for example in FIGS.
11 and 15-17 the flow of water through the water duct 6 can be
easily and more freely be defined, for example based on a desired
flow, water resistance, time of presence of water inside the water
duct 6 and the like. By using a cassette or a series of cassettes
62 having a longitudinal direction Lc, for example extending
substantially between a first side 61A comprising an inlet 64 and a
second side 61B comprising an outlet 66, and cross walls 67
extending non-parallel to said longitudinal direction Lc, a flow W
through the cassettes 62 can be obtained which is also
substantially non-parallel to said longitudinal direction Lc, and
can for example be for example zigzag, passed the cross walls 67.
Instead of or supplementary to said cross walls 67 also other heat
exchanging surface increasing elements could be provided in said
cassette, such as for example ribs, notches, pins, pens, flow
restrictions or any such flow interfering elements as known in the
art, especially including such elements which cannot be extrude
with the slots 60. The cassettes and/or said elements can be made
of the same or different materials than the parts 2, 3.
[0073] The first and/or second part 2, 3 can be provided with
flanges 50 for supporting the heat exchanger.
[0074] FIGS. 15 and 16 show schematically a heat exchanger or part
thereof, comprising at least one slot 60 within a wall 10 of heat
exchanger body 70, for example but not necessarily formed by parts
2, 3 as discussed before. In the embodiment of FIG. 15 there are
shown two slots 60 in a wall 10, each receiving a cassette 62
comprising a part 6A of a water duct 6, one having been fully
inserted. In this embodiment the cassettes 62 comprise a first wall
68 for engaging a wall of said at least one slot 60, for example
wall 10A or 10B, and a labyrinth forming wall or wall complex
extending from said first wall 68, defining said part 6A of a duct
6. The part 6A extends between an inlet side 61A and an outlet side
61B of the cassette 62. In the embodiment shown the labyrinth
forming wall complex comprises two side walls 69 extending along
opposite longitudinal sides of the first wall 68 and cross walls
67, connected to the first wall 68 and alternatingly extending from
one of the side walls 69 towards the opposite side wall 69 but
stopping short from it to leave a relatively small gap 71. Thus a
zig-zag path is obtained forming the part 6A.
[0075] FIG. 17 shows a cassette 62 for use in a heat exchanger 1,
for example as previously disclosed. This heat exchanger can for
example be made of metal sheet material, for example steel,
aluminium, magnesium or metal alloys, such as but not limited to
light metal alloys. It can be made in any suitable way, for example
by setting drafting, pressing, casting or the like methods, known
to the skilled person. In the embodiment shown the cassette 62 is
open at a side opposite the first wall 68, but that side can also
be partly or entirely closed, for example by a second wall, which
can be mounted to the side walls 69 and/or cross walls 67. In
another embodiment cassettes 62 can be placed on top of each other,
the one closing off the open side of the other and possibly vice
versa. When using a cassette 62 which is open at one side, opposite
the first wall 68, a wall 10A, 10B of the slot 60 will close off
the cassette 62 or at least the part 6A of the water duct 6
therein.
[0076] In FIGS. 11 and 15 to 17 the water channel part 6A extends
zig-zag along the walls 67, between inlet 64 and outlet 66, wherein
the distance 71 between adjacent walls extending from the same side
wall 69 decreases from the inlet 64 to the outlet 66, such that the
cross section of the flow channel 6A decreases in that direction.
By varying for example the distances 71 and thus the shape of the
channel part 6A in the cassette 62 or cassettes 62 the flow through
the channel 6 can be amended, even without changing the further
heat exchanger.
[0077] By using one or more cassettes 62, especially cassettes 62
which are open to at least one side, such that it can be made by
for example machining or moulding, such as injection moulding or
fixed core moulding, in a heat exchanger, such heat exchanger can
be more easily made with an appropriate water channel 6. Even if
such heat exchanger is made using a heat exchanger body made by
moulding, no lost core is necessary for forming the water channel
6. A cassette 62 f this disclosure can be a retarder for keeping
the water longer inside the heat exchanger body than when straight
channels 24 are used. By using one or more cassettes 62 in a heat
exchanger defining the water flow the delta T (.DELTA.T) can be set
easily per heat exchanger 1, without the necessity for changing the
further heat exchanger body. The water channel 6, or at least the
part 6A thereof within the cassette 62 can be made more accurate,
thus ensuring an accurate flow and heat exchanging within the heat
exchanger body 70. By using one or more cassettes 62 made outside
the heat exchanger body 70 no debris resulting from the
manufacturing of the water channel will remain and have to be
removed from the heat exchanger body 70.
[0078] In preferred embodiments the burner 34 can be a burner
having a burner deck 47 made using fiber technology. An example of
such material is a material referred to as nit in the relevant
fields, for example as used and supplied Bekaert Combustion
Technology BV, Assen, The Netherlands. A burner range available
using such technology is known as Furinit.RTM. or Aconit.RTM.,
trademarks used by Bekaert Combustion Technology BV, Assen, The
Netherlands. These burners 34 preferably are premix burners, and
can be modulating burners. The fibers can be metal or ceramics or
combinations thereof. A burner 34 for use in the present
description can be for example a burner having a cylindrical burner
deck, a flat or curved burner deck or a dome shaped burner deck, or
any other suitable shape an dimensions suitable for the relevant
heat exchanger. Burners using fiber technology for the burner deck
have at least the advantage that they are compact and still have a
relatively large burning surface area, due to the fibers. The
burners can be modulated over a very large range, for example but
not limited to between 1 and 80 kW/dm.sup.2 or 1-22 kW/dm.sup.2.
The heat exchanger can be very compact, in relation to the
capacity, which renders the use of a compact burner
advantageous.
[0079] A heat exchanger 1 according to this description can be used
as a "stand alone" heat exchanger, for supplying heated medium such
as water. In another embodiment the heat exchanger can be used as a
"add on" heat exchanger, for example coupled to other heating or
power generating means, such as heating devices using "green"
energy, electrics, natural gas or the like. Also a number of these
heat exchangers can be connected, such that depending on heat
demand one or more of these heat exchangers can be fired up to
provide heat.
[0080] 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 walls 10 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 reclining second
walls, for providing a larger space 30. The parts 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, the even
thickness of the bonding layers and heat conducting properties
through the connection thus formed can be achieved 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. In
other embodiments a first part 2 can be used having second walls 11
and intermediate walls 13 extending from both sides of the first
wall 10, as well as fins 14, whereas two second parts 3 can be
provided at the two opposite sides of the first part 2, providing a
space 30 to each side of the first wall 10 of the first part 2.
These spaces 30 and the water channels 24 of the different parts 2,
3 can be used for the same or different heating circuits. Such heat
exchanger can be equipped with one or two burners 34. Shapes and
dimensions, as well as positions of the different parts can be
changed within the scope of the claims as pending. Moreover, more
or less channel parts 8, 24 can be provided than shown, whereas
more than one intermediate wall can be provided, for example two or
more, 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 on and/or in
the first end part 4, the exhaust in and/or on the second end part
5 when the number of intermediate walls is even, having an even
number of direction changes of the gas flow in the space 30. In
embodiments the or at least a slot 60 can be open to a side of the
heat exchanger body 70, such that a cassette 62 can be inserted
into said slot 601 a direction non-parallel to the longitudinal
axis Lc of said cassette 62. A heat exchanger according to the
disclosure could be made without a burner space, for example for
use as an auxiliary heat exchanger or with an external burner.
[0081] In the embodiments shown it is preferred that there will be
no entrapment of gas during use. Especially preferable is that
there will be no entrapment of air in the water ducts, such as in
the cassettes. To this end in embodiments it may be favourable that
there is for example a sustainably vertical positioning of the heat
exchanger, such that the water inlet and outlet are positioned near
or at a lower end of the heat exchanger. In embodiments, especially
such embodiments, it may be favourable to have the burner
positioned at an upper end of the heat exchanger.
[0082] In heat exchangers according to this disclosure in stead of
metal, such as light metal or light metal alloys, also plastic can
be used, for example but not limited to for the cassettes and parts
forming the body or housing of the heat exchanger, such as but not
limited to parts forming part of the heat exchanging space and/or
the water conducting channel and/or the burner.
[0083] These and other alterations and modifications are supposed
to be disclosed within the scope of the claims.
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