AU611084B2

AU611084B2 - Improvements to heat exchangers

Info

Publication number: AU611084B2
Application number: AU74101/87A
Authority: AU
Inventors: Trevor John Bloor; Lawrence John Walton
Original assignee: Zane Solar Systems Australia Pty Ltd
Current assignee: Zane Solar Systems Australia Pty Ltd
Priority date: 1986-06-05
Filing date: 1987-06-02
Publication date: 1991-06-06
Anticipated expiration: 2007-06-02
Also published as: AU7410187A

Description

611084 Ole 16 NamDe- of )plicants Addresses of Applicantk Names of Inventors Address for Service *Trevor John Bloor Lawrence John Walton *both of The Upton Centre, 10~6 Buridall Road, BUNDALL QLD. 4217 *Trevor John Bloor Lawrence John Walton *JOHN R.G. GARDNER, P.O. BOX 255, BROADBEACH Q 4218

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S C C S 4 FORM Regulation 13(1) COMMONWEALTH OF AUSTRALIA~ Patents Act 1952-1973 COMPLETE~ SPECIFICATION FOR~ THE I,',VENTION ENTITLED IMPROVEMENTS TO HEAT EXCHANGERS The following statement is a full description of this invention including the best method of performIng it known to me To: The Commissioner of Patents THIS INVENTION relates to improvements to heat exchangers and in one aspect to heat exchangers adapted for solar heating of water particularly vater from swimming pools. The present invention also relates to connection means for connecting ducts particularly heat exchanger ducts to fluid flow manifolds or other members.

Solar heat exchangers of the type having an absorber formed of a plurality of ducting members which are arranged to be exposed to the sun and which convey water to be heated are well know. For the heating of swimming pools such absorbers are generally formed of a synthetic rubber oe plastics material and in many instances, the absorber is extruded with the ducting members separated by continuous "oo. 5 connecting webs. Examples of such absorbers are shown in U.S.

.Patent Nos. 4269172 and 4270596. So that the absorber may be o connected to water conveying manifolds, it is necessary that 0h the webs be removed from between the ducting members adjacent oo their connection point to the manifolds. This may either be achieved by cutting the webs away from the ducting members or o fconstructing the heat exchanger so that the webs may be 0 o stripped from the ducting members along tear lines fo|med 0 00 SThe above procedures are obviously time consuming and therefor add to the overall cost of the installation.

Furthermore, heat exchangers which have continuous webs separating the ducting members are relatively expensive in material costs whilst the webs tend to shield the lower portion dfthe ducting members from the sun as well as the underlying roof or other supporting surface so that maximum heat transer to the ducting membrs is not achieved.

Many different arrangements have been proposed for connecting ducting members to manifolds or other members through an aperture in a wall thereof such as the arrangement 33 disclosed in our U.S. Patent No. 4597597. In this arrangement the connection assembly comprises three separate parts, a plug which is inserted into the manifold aperture, a spigot V' costrutin th hea exhaner s tht te wes my x I- i rcr inserted into the plug and a sleeve which secures the ducting member to the spigot. Whilst this arrangement functions as an efficient connector assembly, use of three separate connection parts adds to overall cost as well as increasing assembly time.

The present invention aims to overcome or alleviate at least some of the above disadvantages by providing an improved heat exchanger particularly suited to solar heating applications which is relatively inexpensive both in its component cost and installation cost and which will function in a reliable and .o o efficient heat exchanging manner. The present invention also oo6 provides an improved connection assembly and connector therefore particularly suited for the connection of the ducts or tubes of the above heat exchanger absorber to a manifold. The connector and 0000 Cooo connection assembly, however, may be used in a range of o°1O 5 applications for the connection of tubes or ducts to manifolds, containers or other objects.

With the above and other objects in view, the present invention resides broadly in one aspect in a heat exchanger °oo000 including an absorber formed of flexible plastics cer other 0°0 elastomeric material and at least one manifold, said absorber including a plurality of substantially parallel ducting members and °ooo" a plurality of web portions extending between adjacent ducting o ,o members and spacing said ducting members apart, said web porti being arranged at spaced apart positions longitudinally of saia absorber so as to define a plurality of gions between adjacent iI ducting members free of said web portions, said web portions between adjacent ducting members being substantially aligned transversply of said absorber, said absorber being transversely severed in at least one said region whereby to define ends of said ducting members substantially free of said webs portions, said ends being connected to said at least one manifold.

Preferably said absorber is transversely severed at regions spaced apart longitudinally of said absorber to define opposite ends of said ducting members substantially free of said web portions and the heat exchanger includes a pair of said S A.'manifolds, one said manifold being adapted to convey water to said I 3 'UI I member ends are connected to he respective said manifolds.

Suitably said manifolds are provided with a plurality of longitudinally spaced apertures in the walls thereof and there are provided a plurality of connectors engaged with said opposite ends of said ducting members and received in respective said apertures.

Preferably each said connector includes an internal hollow spigot portion and an outer skirt portion spaced from said spigot portion and defining a recess therebetween for receipt of an end of a said ducting member. Suitably said spigot portion and said skirt portion are joined at the leading end of said connector to define a blind said recess and wherein said skirt portion is engaged with a said manifold aperture to sealingly sandwich said ducting member end in said recess. Suitably also said skirt 0 0:"000 portion includes an enlarged annular head portion at a position 0o spaced from said leading end of said connector and disposed in use :0o on the outer side of said manifold wall and said skirt portion is annularly enlarged at a position spaced from said head portions, said annular enlargement being disposed on the side of said manifold wall opposite said head portion.

6o029 Most preferably, the dimension of said web portions in a direction longitudinally of said absorber is substantially 00 00 smaller than the longitudinal spacing of said web portions.

o °0 0 Preferably said ducting members are tubular and wherein said web portions extend diametrically of said ducting members.

The present invention in a further aspect provides a .6:o4: method of forming a heat exchanger comprising the steps of providing an absorber formed of flexible plastics or other elastomeric material and a pair of manifolds, said absorber including a plurality of substantially parallel ducting members and a plurality of web portions formed integrally with and extending between adjacent said ducting members so as to space said ducting members apart, said web portions being arranged at spaced apart positions longitudinally of said absorber, respective said web portions defning therebetween, longitudinally spaced regions between adjacent ducting members free of said web portions, said web portions between adjacent ducting members being substantially 6' i ylara ~na~ ~o~ur~~ aligned transversely of said absorber, and a pair of manifolds, said method including the steps of transversely severing said absorber at two spaced said regions to define ends of said ducting members substantially free of said web portions and connecting at least some of said ends to said manifolds.

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:- Fig. 1 is a perspective view of a solar heating installation incorporating a heat exchanger and connector according to the present invention; e o o 0e0o' Fig. 2 is a perspective partly cut-away view of portion 0 of the heat exchanger of Fig. 1; Fig. 3 is a plan view showing portion of the absorber of 0000 00o the heat exchanger; S oo Figs. 4 and 5 are respective plan and part sectional elevational view of a connector for connection of a ducting member of the hat exchanger to a manifold; and ,o200 Fig. 6 illustrates in sectional view the manner of 0 0 0oo0o connection of a ducting member to a manifold via the connector shown in Figs. 4 and o00 00 Referring to the drawings and firstly to Figs. 1 to 3, there is illustrated a solar heating system co000 0 0 0 00 0 j 4a F I incorporating a heat exchanger 11 according to the present invention which is suitably mounted directly on the roof of a building for example the roof of a dwelling. The system in this instance is adapted for heating of water in a swimming pool and for this purpose, the heat exchanger 11 includes a supply manifold 12 which receives water pumped from the pool filter assembly and a return manifold 13 which directs heated water back into the pool.

The heat exchanger 11 includes an absorber formed of a plurality of groups 14 of ducting members or tubes connecting at opposite ends to the manifolds 12 and 13 via respective connectors 16. The ducting members 15 are spaced apart to lie in a substantially parallel relationship by a plurality of integrally formed webs 17 which preferably extend diametrically of the tubes 14. Preferably the groups ao: of tubes and integral webs are extruded from a P.V.C.

Ssoo° material such as that known under the trade mark SUNPRENE.

Q0oo As shown the webs 17 are arranged at spaced apart 0 0 O0 positions along the tubes 15 so as to form between the tubes o 15 a plurality of areas substantially free of webs 17. Where it is required to connect the groups of tubes 12 to the manifold 12 or 13, the tubes 15 may be simply transversely I o g severed in an area where the tubes 15 are free of the webs ooo 17 to enable engagement of the tubes 15 with the connectors 0 00 16. This arrangement of webs 17 also facilitates passage 000 of the groups of tubes 15 around or 'past obstructions such as vent pipes in a roof surface upon which the heat heat exchanger 11 is laid. Furthermore, as the webs 17 leave a major area of the tubes 15 exposed, maximum exposure to direct radiation from the sun is achieved. Furthermore, this arrangement permits the surface of the underlying roof to be largely exposed to the sun so that the tubes 15 also receive high reflected radiation therefrom. The above described arrangement also ensures that the roof area will dry rapidly in the event of rain to thereby reluce the risk of corrosion consquent upon water being trapped beneath the webs 17.

Suitably the tubes 15 in each group 14 are 7.2mm.

external diameter and spaced apart on centres typically 5'7 of 14.6mm. Preferably also the webs 17 are in the range of to 30mm. in length and most preferably 20mm. whilst the preferred spacing between the webs is 120mm. to 180mm., typically 150mm. Furthermore, the groups of tubes 15 are preferably formed as an extrusion with continuous webs between the tubes 15, portions of which are punched out or otherwise removed after extrusion to form the areas 18.

Alternatively, the groups of tubes 15 may be formed simply as an extrusion with the areas 18 free of webs being formed during the extrusion process.

As stated above the groups 14 of tubes 15 and webs 17 are preferably constructed of a P.V.C. material.

Alternatively, the groups of tubes may be an elastomer such as E.P.D.M. or other synthetic of natural flexible material.

Preferably, the groups of tubes comprise an oo0opo eight(8) tube extrusion although any number of tubes 15 may 0ooo, be incorporated as desired.

S000 SO The heat exchanger 11 may of course be arranged in 0 0 0 any known configuration such as between spaced supply and 0000 *oo. 20 return manifolds as shown in Figs. 1 and 2 or arranged so o coo that a pair of tubes 15 are interconnected at one end and connected at their opposite ends to respective supply and return manifolds. The webs 17 may also be arranged 0 0 SonOP substantially tangentially to the tubes 15 however in 0 00 either case, the webs 17 are preferably relatively thick and therefor substantially rigid so that the tubes 15 can be 0 0 0 maintained in a spaced apart attitude.

Referring now to Figs. 4 to 6, there is illustrated S details of the connector 16 for connecting ducting members such as the tubes 15 to a manifold 12 or '3 through an aperture 19 in a wall 20 thereof. The connector 16 includes a generally tubular internal hollow spigot portion 21 and an outer concentric skirt portion 22 secured to by being formed integrally with the leading end of the spigot portion 21 and defining with the spigot portion 21 an annular recess 23 for receipt of an end of the tube 15. Preferably the outer wall 24 of the spigot portion 21 diverges outwardly so that the recess 23 tapers in width towards the leading end of the connector 16. Formed integrally on the outer wall 6 of the skirt portion 22 is an annular head portion 26 and a pair of annular enlargements or ribs 27 are formed on the wall 25 at a position spaced from the head portion 26.

Suitably also the leading end of the connector 12 is externally tape'red at 28 to facilitate its insertion into the aperture.

In use and as shown in Fig. 6, the end of a tube is initially forced into the tapering recess 23 so that it is held between the spigot portion 21 and skirt portion 22. If necessary to ensure that the tube end remains attached to the connector 16, a small amount of adhesive may be applied to the end of the tube 15 or recess 23. The connector 16 may be then forced in to the aperture 19 so that the ribs 27 are radially compressed as they pass through the aperture 19 to be located on the opposite side o of the manifold wall 20 to the head portion 26. The 00900 0 connector skirt portion 22 and aperture 19 are of such a 9000 size that the skirt portion 22 is radially compressed in the 43 0 000 region between the head portion 26 and ribs 27 so that the 0000 0 20 end of the tube 15 is sealingly squee;zed and sandwiched o between the inwardly compressed skirt portion 22 and tubular spigot portion 21. At the same time, the ribs 27 serve to 0 0 inhibit withdrawal of the connector 16 from the aperture 19 2500 whilst the preferred configuration of head portion 26 as a025illustrated that is of generally domed skirt form, 0 '000 improves sealing on the opposite side of the apetture 19.

The above arrangement also constrains the tube 15 against withdrawal both from the connector 16 and manifold.

In the arrangement shown in Fig. 2, a plurality o'ff apertures 19 are provided longitudinally of the respective manifolds 12 and 13 and preferably, the apertures 19 are provided alternately in rows to reduce the risk of cracking of the manifolds 12 and 13 between adjacent apertures 19.

of course, many variations may be made to the constructional details of the connector 16. For example, the recess 23 may be made of non-tapering form or alternatively, the inner wall of the skirt portion 22 may converge towardis the end of the connector 16 to define the taper in the recess 23- The ribs 27 may be increased in radial -11 dimension if required whilst only one or any number of ribs may be employed. The head portion 26 may also be altered in configuration.

Preferably, the connector 16 is formed of a P.V.C. material such as SUNPRENE however it may also be an elastomer or other sythetic or naturalflexible or resilient material.

It will be apparent from Figs. 2 and 3 that the connectors 16 permit suitable sealing of the tubes 15 to the manifolds even if a small web portion remains attached to the tubes 15 as where the webs may be severed between the tube£. Whilst the connectors 16 as described above are used in a heat exchanger/ manifold connection, it will be apparent that such a connector may be employed in any application 0o 015 where a duct is to be connected to a member or container a 0 n through an aperture in a wall thereof.

0900 o In the heat exchanger of Figs. 1 and 2, it is o00 preferred that the groups of tubes 15 are attached to the 000" roof surface for example by means of an adhesive and o00 too20 furthermore, a clip arrangement is preferably provided to secure the manifolds to the roof. In a preferred constructoo ion as illustrated in Fig. 2, the manifolds 12 and 13 are 0 0 0° formed as a coextrusion with the inner portion comprising o o a normal P.V.C. pipe with an outer protective skin of a a. 25 plastics material such as that known under the trade mark 0 LURAN

S.

Whilst the above has been given by way of illustrative embodiment of the invention, it will be S realised that many modifications and variations may be made thereto as would be apparent to persons skilled in the art without departing from the broad scope and ambit of the invention as defined in the appended claims.

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Claims

1. A heat exchanger including an absorber formed of flexible plastics or other elastomeric material and a pair of manifolds, said absorber including a plurality of substantially parallel ducting members and a plurality of web portions formed integrally with and extending between adjacent said ducting members so as to space said ducting members apart, said web portions being arranged at spaced apart positions longitudinally of said absorber, respective said web portions defining therebetween, longitudinally spaced regions between adjacent ducting members free of said web portions, said web portions between adjacent ducting mambers being substantially aligned transversely of said absorber, said absorber i being transversely severed at two spaced said regions of said S absorber to define ends of said ducting members substantially free of said web portions, at least some of said ends being connected to said manifolds.

2. A heat exchanger according to Claim 1 wherein one said S manifold is adapted to convey water to said absorber and the other o said manifold is adapted to convey water from said absorber.

3. A heat exchanger according to Claim 2 wherein said manifolds are provided with a plurality of longitudinally spaced apertures in the walls thereof and there being provided a plurality S"of conni~tors engaged with at least some of said ends of said 6o ducting members and received in respective said apertures.

4. A heat exchanger according to Claim 3 wherein each said Sconnector includes an internal hollow spigot portion and an outer skirt portion spaced from said spigot portion and defining a recess therebetween for receipt of an end of a said ducting member.

A heat exchanqer according to Claim 4 wherein said spigot portion and said skirt portion are joined at the leading end of said connector to define a blind said recess and wherein said skirt portion is engaged with a said manifold aperture to sealingly sandwich said ducting member end in said recess.

6. A heat exchanger according to Claim 5 where in said skirt portion includes an enlarged annular head portion at a position spaced from said leading end of said connector and disposed in use 9 *'V ^hy f- on the outer side of said manifold wall and wherein said skirt portion is annularly enlarged at a position spaced from said head portion, said annular enlargement being disposed on the side of said manifold wall opposite said head portion.

7. A heat exchanger according to any one of the preceding claims wherein the dimension of said web portions in a direction longitudinally of said absorber is substantially smaller than the longitudinal spacing of said web portions.

8. A heat exchanger according to any one of the preceding claims wherein said ducting members are tubular and wherein said web portions extend diametrically of said ducting members. 0

9. A method of forming a heat exchanger comprising the steps 000 oo*o" of providing an absorber formed of flexible plastics or other 09°° o elastomeric material -ar r -pof m -nif said absorber including a plurality of substantially parallel ducting members and 00oo0 goo a plurality of web portions formed integrally with and extending between adjacent said ducting members so as to space said ducting members apart, said web portions being arranged at spaced apart positions longitudinally of said absorber, respective said web .ooo0: portions defining therebetween, longitudinally spaced regions o*000 between adjacent ducting members free of said web portions, said S web portions between adjacent ducting members being substantially :0"l00 aligned transversely of said absorber, and a pair of manifolds, 0 said method including the steps of transversely severing *id absorber at two spaced said regions to define ends of sait "'t6 memberc substantially freo of said web portions and con at 0 least some of said ends to said manifolds.

A heat exchanger substantially as hbpifnbefo.- i rsied with reference to the accompanying drawings.

11. A method of forming a heat exchanger substantially as hereinbefore described with reference to the accompanying drawingo. DATED this nineteenth day of March 1991 TREVOR JOHN BLOCk NOD JOHN WALTON By Our Patent At4teAr. JOQHN ,Q