U.S. patent application number 13/706247 was filed with the patent office on 2013-06-06 for condensate drain pan.
This patent application is currently assigned to Kumagaya Kunststoffen V.o.f.. The applicant listed for this patent is JMK Heating B.V., Kumagaya Kunststoffen V.o.f. Invention is credited to Johan Kuijt, Johannes Gerardus Petrus Van Kessel.
Application Number | 20130139537 13/706247 |
Document ID | / |
Family ID | 47263184 |
Filed Date | 2013-06-06 |
United States Patent
Application |
20130139537 |
Kind Code |
A1 |
Kuijt; Johan ; et
al. |
June 6, 2013 |
Condensate Drain Pan
Abstract
A condensate drain pan in particular for use in combination with
a HVAC system, comprising a sump, an inlet and an outlet for gases,
in particular combustion gases, as well as an outlet for
condensate. The sump is made of a non-corrodible or
corrosion-resistant material, such as a chemically inert-synthetic
plastics material, in particular a thermoplastic elastomer,
preferably elastic thermoplastic copolyester. The pan may be
produced by rotational molding, preferably as one piece. The
invention also concerns a HVAC system provided with such condensate
drain pan.
Inventors: |
Kuijt; Johan; (Deventer,
NL) ; Van Kessel; Johannes Gerardus Petrus; (Heeze,
NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JMK Heating B.V.;
Kumagaya Kunststoffen V.o.f; |
Helmond
Holten |
|
NL
NL |
|
|
Assignee: |
Kumagaya Kunststoffen
V.o.f.
Holten
NL
JMK Heating BV.
Helmond
NL
|
Family ID: |
47263184 |
Appl. No.: |
13/706247 |
Filed: |
December 5, 2012 |
Current U.S.
Class: |
62/291 ; 264/311;
425/418 |
Current CPC
Class: |
F24H 9/165 20130101;
F25D 21/14 20130101 |
Class at
Publication: |
62/291 ; 425/418;
264/311 |
International
Class: |
F25D 21/14 20060101
F25D021/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 5, 2011 |
NL |
2007923 |
Claims
1. A single part condensate drain pan for use in combination with a
HVAC system, comprising a sump, an inlet, an outlet for combustion
gases, as well as an outlet for condensate, and wherein at least
the sump is made of a non-corrodible or corrosion-resistant
material.
2. A condensate drain pan according to claim 1, wherein the sump is
of a chemically inert-synthetic plastics material.
3. A condensate drain pan according to claim 1, wherein the plastic
material is an elastic thermoplastic polymer.
4. A condensate drain pan according to claim 1, wherein the sump is
manufactured by rotational molding.
5. A condensate drain pan according to claim 1, wherein one or more
of the inlet for gases, the outlet for gases, the outlet for
condensate and a siphon form an integral part of the sump.
6. A condensate drain pan according to claim 1, wherein the sump is
provided with an inspection port.
7. A condensate drain pan according to claim 6, wherein one or more
of the inlets, outlets, siphon and inspection ports is provided
with thread.
8. A condensate drain pan according to claim 6, wherein the
inspection port is provided with a cover.
9. A condensate drain pan according to claim 1, wherein the sump
has a profiled internal bottom.
10. A condensate drain pan according to claim 1, wherein the
condensate drain pan is suitable for placement on a surface.
11. A condensate drain pan according to claim 10, wherein the
condensate drain pan has a support surface to support the HVAC
system or a part thereof.
12. A condensate drain pan according to claim 10, wherein the
condensate drain pan is provided with reinforcements.
13. An HVAC system provided with a condensate drain pan according
to claim 1.
14. A multi-piece mold for manufacturing a condensate drain pain
comprising a left portion, a right portion, wherein the left and
right portion provide an outlet, a sump, and an outlet, and a top
portion providing an inlet.
15. A method of producing a condensate drain pan according to claim
1, comprising the steps of providing a three or four part mold,
combining the mold, providing a thermoplastic elastomer, and
forming the condensate drain pain by rotational molding.
16. The condensate drain pan according to claim 2, wherein the
plastics material is a thermoplastic elastomer.
17. The condensate drain pan according to claim 3, wherein the
plastics material is a copolyester.
18. The condensate drain pan according to claim 17, wherein the
copolyester is one or both of polypropylene copolymer and
polyphenylene sulphide.
19. The condensate drain pan according to claim 10, wherein the
condensate drain pan is provided with legs.
20. The method of claim 15, wherein the thermoplastic elastomer is
an elastic thermoplastic copolyester.
21. The method of claim 20 wherein the copolyester is one or both
of polypropylene copolymer and polyphenylene sulphide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a continuation application of the Dutch
Patent Application Serial Number NL2007923, entitled "Condensate
Drain Pan", to JMK Heating B. V., Helmond, the Netherlands, and
Kumagaya Kunststoffen V.o.f., Holten, the Netherlands, filed on
Dec. 5, 2011, and the specification and claims thereof are
incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0003] Not Applicable.
COPYRIGHT MATERIAL
[0004] Not Applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The invention relates to a condensate drain pan in
particular for use in combination with a HVAC system, comprising a
sump, an inlet and an outlet for gases, in particular combustion
gases, as well as an outlet for condensate. The invention further
concerns a HVAC system provided with a condensate drain pan
according to the invention.
[0007] 2. Description of Related Art
[0008] A condensate drain pan is for instance applied in HVAC
systems (heating, ventilation, air conditioning), in particular in
heating systems. For instance in a heating system, combustion gases
of a boiler flow through a heat-exchanger. Most of the heat of the
combustion gases will be transferred to a fluid in the heating
system. The combustion gases then flow through a flue. Combustion
gases contain water vapor and combustion product gases such as
SO.sup.2 and CO.sup.2. During cooling of the combustion gases the
vapor will condensate. The condensate water will contain dissolved
gases and is therefore acid. The acid condensate water may react
with the drain pan and the flue. In time regular inspection is
required and may result in costly replacement of affected
parts.
[0009] Such condensate drain pan is for instance described in GB
2.425.588. The sump of the condensate drain pan is made of a metal
suitable for application in an acid environment, such as aluminum
or stainless steel. Still such sump is vulnerable to acid
corrosion, in particular for the, above average acid condensate of
the flue. GB 2.425.588 therefore provides for a collector device
located between the flue and the sump. The collector device is made
of non-corrodible or corrosion-resistant material. This known
condensate drain pan has several disadvantages. The main part of
the sump, in particular the metal part between the heat exchanger
and the flue, is still vulnerable to acid corrosion. Although the
condensate of the heat exchanger is less acid than that of the
flue, it still provides an acid environment. Therefore also this
condensate drain pan requires regular inspection. It has to be
designed such that inspection is possible, for instance by applying
expensive inspection ports in the sump, or by opening the
condensate drain pan during inspection. Opening of the condensate
drain pan for inspection and replacement of the drain pan will in
most cases also require replacement of the sealing. Inspection of
the condensate drain pan and replacement of affected parts thereof
is therefore expensive. Further, this condensate drain pan consists
out of many parts, which makes it expensive and vulnerable for
failure. Moreover, the several drainage outlets are vulnerable for
obstruction, for instance by calcification or acid disposition. In
addition, the design freedom is restricted. The outlet of the sump
has to be positioned under the flue. The requirement that the parts
of the condensate drain pain should be replaceable, further
restricts the freedom of design. For this reason, in general, at
least the sump is releasable attached to the flue and the heat
exchanger, while the flue and the heat exchanger are supported
independent of the sump. The heat exchanger may for instance be
placed on a supporting frame.
[0010] Further, EP 1 182 408 (A2) recites a heater with an exhaust
gas and condensate collecting bath passing directly through a
channel in its side wall to the exhaust connection. The bath, the
channel and the connection are combined in a one-piece
injection-molded connecting component able to be connected by
connecting elements to the underside of the cast heat radiator.
[0011] However, the above document does not indicate how an outlet
can be made using the mold of FIG. 2 thereof. Even further, the
mold of FIG. 2 can from a practical point of view not lead to a
product as indicated therein, especially as element 50 is either
obstructing the movement of the mold, or provided as a detachable
element or the like, leading to leakage when molding. In general it
is noted that injection molding or blow molding does not provide
products having required specifications. As a consequence further
processing is required, making the products expensive. Also the
quality, life time, product strength, etc., are not sufficient. In
short, the recitation of the above document cannot be put into
practice.
[0012] WO2009003244 (A1) recites a water heater for heating water
including various elements. In an example a water heater having a
condensate duct to direct condensate into the water for chemically
treating the water is recited.
[0013] The document is not considered relevant for the present
invention, as it does not relate to a condensate drain pan at all;
it only relates to a collection base of plastic. The base itself
has no further function.
[0014] U.S. Pat. No. 5,476,088 (A) recites methods and apparatus
for exhausting flue products and removing condensate from a
combustion of air/gas mixtures provide a condensate collecting pan
for flue products. That pan is provided with an inlet for flue
products and condensate, and with an outlet for flue products
spaced from that inlet. That inlet is provided with a larger
cross-section for flue product and condensate flow than the outlet.
A space is provided in the pan for a flow of flue products from the
inlet at a substantially even velocity across the larger
cross-section of the inlet to the smaller cross-section outlet.
Condensate collecting in that space is removed from the pan.
[0015] The above document is silent on the material of the pan.
Further no exhaust is provided.
[0016] WO2009082090 (A1) recites a heat exchanger of an upward
combustion type condensing boiler. The heat exchanger includes a
condensed-water tray that discharges condensed water generated from
the latent heat exchange unit. A latent heat exchange unit is
installed in such a manner that the flow direction of the exhaust
gas passing through the latent heat exchange unit vertically
coincides with the falling direction of condensed water generated
from the latent heat exchange unit.
[0017] The above condensate water tray is assembled out of many
pieces.
[0018] DE 10 2006 026613 A1 recites amongst others a plastic siphon
in order to prevent drying up thereof.
[0019] Many of the above documents can not relate to a condensate
drain pan made of a plastic material, as it is not possible to
manufacture such a plastic by molding, specifically by injection
molding. Dimensional tolerance of such molding are in the order of
less than 1 mm, such as 0.2 mm. However such precise components
made of plastic typically have a variation in dimensions of a few
mm, such as 2-5 mm, which is fully unacceptable for the intended
purpose. Such is particularly the case when parts of plastic need
to be attached or combined with other elements, or need to be
melted together, such as for outlets and inlets. Also provision of
a mold is typically quite expensive.
[0020] The present invention intends to solve one or more of the
problems of the prior art as described above, and it is in
particular an objective of the invention to provide a condensate
drain pan that is durable in acid environment.
BRIEF SUMMARY OF THE INVENTION
[0021] The condensate drain pan according to the invention is
characterized by one or several of the appended claims.
[0022] In a first aspect of the invention at least the sump is made
of non-corrodible or corrosion-resistant material. The material
used is preferably also resistant to acids, such as to a pH of less
than 5, preferably less than 3, and can withstand high
temperatures, such as up to 120.degree. C. Such sump will not
corrode, even not in the aggressive acid environment of combustion
gases and condensate of boilers. Inspection of the condensate drain
pan is therefore not required and under normal circumstances the
parts of the condensate drain pan need not to be replaced.
Inspection ports may be omitted and more design freedom is
obtained. The position of the outlet for condensate and that of the
outlet for combustion gases may be chosen independent of each
other.
[0023] According to the invention a suitable material may be a
chemically inert-synthetic plastics material, such as in particular
a thermoplastic elastomer, of which category elastic thermoplastic
polymer, such as a copolyester proves to be very suitable. In
particular polypropylene and polyphenylene sulphide are suited.
These material are not only non-corrosive or corrosion resistant,
they also provide a good formability, strength and heat resistance.
The choice of a suited polymer is not trivial. As mentioned the
polymer should be resistant to a relative high and especially a
relative low pH, it should be capable of withstanding high
temperature, such as above 100.degree. C., and low temperature
(e.g. during transport -20.degree. C.), it should be capable of
withstanding expansion and shrinking during temperature variations
and temperature cycles, it should not absorb water. Further many
polymers cannot be processed using rotation molding. For not too
high temperatures polypropylene may be used, for even higher
temperature polyphenylene sulphide is a good candidate. In order to
have polymers being processed in rotation molding it is preferred
to use pellets or granules, preferably pellets of a suitable size
having a relatively narrow size distribution, e.g. of 1 sigma of
10% relative, preferably less than 5% relative, even more
preferably less than 2% relative. It is noted that the prior art
typically relates to use of a metal, such as stainless steel or
aluminum. These metals will however corrode, typically at
unexpected locations.
[0024] The condensate drain pan may be manufactured by rotational
molding. Rotational molding provides very smooth surfaces, which
facilitates the condensate to stream to the outlet for condensate.
Even (large) condensate drain pans with a complicated design may be
produced in a single production step. The condensate drain pan may
accordingly be one single part, avoiding assembly of parts, sealing
thereof and edges that easily get contaminated, the typical places
of condensate accumulation and therefore corrosion. The present
method provides a condensate drain pan substantially free of
stress, having a high durability. The present method also allows
for a large variety in shape and size of products. Also the
tolerance of e.g. inside dimensions can now be met. Such inside
tolerance is in the order of .+-.0.5% or less, such as .+-.0.1%
(relative). A typical thickness of the condensate drain pan is 2-20
mm, such as 3-10 mm, or 5-8 mm. A thickness of the mold is
typically 8-10 mm. The life time of the present condensate drain
pan is increased dramatically, such as up to 10 years and longer.
The sump may be profiled to further facilitate streaming of
condensate toward the outlet opening. According to the invention
even the inlets and outlets of gases and condensate may form an
integral part of the sump and may be produced in the single
production step. The condensate outlet may be shaped as siphon. The
invention further provides for the possibility to have an
inspection port as integral part of the sump. Such inspection port
may be provided with a cover. According to the invention one or
more of the inlets, outlets, siphon and inspection port may be
provided with, internal or external, thread.
[0025] To a further aspect of the invention the condensate drain
pan is suitable for placement on a surface. Such condensate drain
surface pan does not require attachment to for instance a heat
exchanger. The condensate drain pan may in this respect be provided
with legs in order to obtain free space under the sump for the
outlet and/or the siphon. In a further embodiment of the invention
the condensate drain pan has a support surface to support the HVAC
system or a part thereof such as a heat exchanger. A support frame
for the HVAC system may therefore be omitted. The condensate drain
pan may accordingly be provided with reinforcements.
EXAMPLES
[0026] The various aspects of the invention will now be described
in more detail and will be elucidated, by way of example only, with
reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0027] The drawings show in
[0028] FIG. 1, a heat exchanger of a HVAC system, provided with a
state of art condensate drain pan;
[0029] FIG. 2, a schematic cross sectional view of the system of
FIG. 1;
[0030] FIG. 3, a schematic view of an embodiment of the condensate
drain pan according to the invention;
[0031] FIG. 4, a schematic view of another, self-supporting
embodiment of the drain pan according to the invention;
[0032] FIG. 5, a heat exchanger of a HVAC system, provided with a
condensate drain pan according the invention and supporting the
heat exchanger;
[0033] FIG. 6, a mold according to the invention; and
[0034] FIG. 7, and in FIG. 8 a condensate drain pan obtained.
DETAILED DESCRIPTION OF THE INVENTION
[0035] In FIG. 1 a state of art heat exchanger 1 is shown. The heat
exchanger 1 has at its upper side a burner with an inlet 4 for
gases. Also an inlet 2 and an outlet 3 for the liquid of a heating
system are provided. The heat exchanger 1 is placed on a supporting
structure 5. Under the heat exchanger 1 a condensate drain pan 6 is
provided. The condensate drain pan 6 has an outlet 7. The outlet 7
may be provided with a flue.
[0036] The heat exchanger 1 of FIG. 1 is in a schematic
cross-sectional view shown in FIG. 2. In FIG. 2 at the outlet 7 a
flue is positioned. Gases will enter the heat exchanger 1 at inlet
4 and will be heated by a burner. Fluid of heating systems enters
the heat exchanger 1 at inlet 2, flows through the heat exchanger 1
and will exit at outlet 3. In counter flow the flue gases will heat
the fluid of the heating systems. The flue gases will flow to the
sump 6 and exit the sump 6 at outlet 7. The outlet 7 is provided
with a flue 8. The flue 8 will guide the combustion gases to the
environment.
[0037] The combustion gases cool down and expand while cooling down
in the heat exchanger 1 and in the flue 8. Combustion gases contain
water vapor and combustion product gases such as SO.sup.2 and
CO.sup.2. During cooling of the combustion gases the vapor will
condensate. The condensate water will contain dissolved gases and
is therefore acid. The condensate water will be accumulated in the
sump 6 and will leave sump 6 through outlet 12. The acid condensate
water may react with the drain pan and the flue. In time regular
inspection is required and may result in costly replacement of
affected parts. Accordingly all these parts are replaceable
attached to the heat exchanger. The sump of the state of art
condensate drain pan is made of a metal suitable for application in
an acid environment, such as aluminum or stainless steel. Still,
such sump is vulnerable to acid corrosion, in particular for the,
above average acid condensate of the flue. Therefore, in this prior
of art condensate drain pan, a collector device 13 is provided and
located between the flue and the sump. The collector device 13 is
made of non-corrodible or corrosion-resistant material. This is an
expensive, complicated solution and still is not satisfying as it
does not solve the corrosion problem of the condensate drain pan in
general and as it is still vulnerable for clogging.
[0038] FIG. 3 provides a schematic view of an embodiment of the
condensate drain pan according to the invention. The lower part of
a heat exchanger 35 is placed on a support frame 36. The support
frame provides even better dimensional specifications of the
product, such as .+-.0.05%. Under the heat exchanger 35 a
condensate drain pan 30 according to the invention is provided. The
condensate drain pan 30 consists of one piece. The condensate drain
pan 30 consists of a sump 37, an outlet 31 for connection with a
flue, an outlet 32 with siphon 41 and an inspection port 33, all
formed in one single production step. The outlets 31, the siphon 41
and the inspection port 33 are provided with thread. On the outlet
31 a flue may be positioned. The outlet 32 with siphon 41 may be
connected to a sewer. On the inspection hole 33 a cover 34 is
placed. The condensate drain pan 30 is made of a chemically
inert-synthetic plastics material in particular a thermoplastic
elastomer such as elastic thermoplastic copolyester. These
materials are also heat resistant and strong. Moreover they prove
to be very suitable for rotational molding. Rotational molding not
only enables production of the condensate drain pan as one part, it
also provides a smooth internal surface and rounded edges. This
will enhance flow of the condensate to outlet 32. In this respect
the sump 37 may have an internal surface that is profiled, for
instance with a sloped bottom with the lower point at the outlet
32. The outlet 32 of condensate drain pan 30 according to the
invention, may be placed at any suitable position under the sump
37. In general the teachings of the invention provide substantial
design freedom for the condensate drain pan 30 as such and for its
application in HVAC systems in general. The condensate drain pan 30
is resistant to corrosion and therefore replacement of parts due to
corrosion will not any longer occur. Although in this embodiment
the pan 30 is provided with an inspection port 33, inspection for
corrosion is not any longer required. Such inspection port 33 is
still provided to conform present specifications for condensate
drain pans. The expectation is however that in time, due to the
invention, such requirement will disappear from specification.
[0039] The present invention therefore provides a `sealed for life`
solution. The embodiment of the invention as shown in FIG. 4 is
such sealed for life condensate drain pan. An inspection port has
been omitted. The upper part of the sump 37 of the condensate drain
pan 30 is provided with inlet 38 for connection with a heat
exchanger. The edge of inlet 38 is provided with a groove 39. In
the groove 39 a sealing may be positioned. A Quad ring will provide
a dynamic sealing between the condensate drain pan and a heat
exchanger. The condensate drain pan 30 is provided with legs 40 and
may accordingly be self-supporting placed on a surface. As the
condensate drain pan 30 according to the invention is very strong,
which strength may be further increased by applying suitable
reinforcements, the condensate drain pan 30 may even support the
heat exchanger. Accordingly the support frame 36 as shown in the
embodiment of FIG. 3 may even be omitted. In FIG. 5 such
combination is shown. The condensate drain pan 30 is provided with
legs 40 and placed on a surface. On the condensate drain pan 30 the
heat exchanger 1 is positioned. The condensate drain pan 30 is
sufficiently strong to support the heat exchanger 1 and as the
combination is sealed for life the combination will be connected
during life time of the heating system.
[0040] In FIG. 6 a multi (three) -piece mold is shown. A left part
61a, a right part 61b and a top part 64 forming a condensate pan
61. Further the mold is provided with bars 62 to make a support 36.
In principle the various pieces may be further sub-divided into
extra pieces. The mold is preferably made from aluminum.
[0041] In FIG. 7 a condensate drain pan 71 obtained by the mold of
FIG. 6, further having sealing rings for exhaust gas 76, 77, bars
82 and an outlet 75 are shown.
[0042] In FIG. 8 a condensate drain pan 81 obtained by the mold of
FIG. 6, further having sealing rings 84 for sealing between the
condense drain pan and heat exchanger 85 gas 76 and 77, are
shown.
[0043] To the person skilled in art it is obvious that the above
given embodiments represent only a few of the many possible
variations in which the condensate drain pan according to the
invention may be embodied. Therefore the embodiments given here
must be understood as an elucidation to the appended claims without
limiting the scope of the invention. Within the protective scope
numerous variations are conceivable. For instance rotation molding
also provides the possibility to apply inserts, for instance
threaded insert for connection of the condensate drain pan with a
heat exchanger.
* * * * *