CA1091564A

CA1091564A - Method and an apparatus for manufacture of cylindrical rotor structures for moisture and/or heat exchangers

Info

Publication number: CA1091564A
Application number: CA278,159A
Authority: CA
Inventors: Per Norback; Ake Lindgren
Original assignee: Carl Munters AB
Current assignee: Carl Munters AB
Priority date: 1976-05-19
Filing date: 1977-05-11
Publication date: 1980-12-16
Also published as: FR2351754A1; FR2351754B1; DE2722102B2; SE7605703L; SE412023B; DE2722102C3; JPS52140957A; GB1570734A; DE2722102A1

Abstract

A METHOD AND AN APPARATUS FOR MANUFACTURE OF CYLINDRICAL
ROTOR STRUCTURES FOR MOISTURE AND/OR HEAT EXCHANGERS.

Abstract of the Invention The invention relates to manufacture of a rotor mass for moisture and/or heat transferrers and composed of alter-nately plane and corrugated layers of thin sheet material with the corrugations forming axially extending fine channels.
The layers are assembled in predetermined positions relative one another and joined together by gluing. As the glues hitherto used harden relatively slowly the layers, especially when consisting of very thin sheet material before solidifi-cation of the glue are exposed to displacement relative one another which may cause undesired deformations of the rotor and in particular the fine channels. To avoid this danger the invention suggests application of a second glue type in addition to the conventional glue type. Whereas the latter imparts to the rotor structure required mechanical strength, the additional glue is of a kind solidifying almost instant-aneously and thereby effecting a first direct sticking between the layers immediately upon assemblage and thus ensuring sufficient protection against displacement of the layers relative one another and deformation of the fine axial channels during subsequent assemblage, storage and transport of the rotor. The invention includes also an apparatus for carrying out the method in a simple and reliable manner.

Description

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Fl_ld of the Inl_ntion This invent-ion relates to manufacture of rotor structures for exchangers -for effecting changes in the physical properties of a medium by interaction with an other medium.
More particularly this invention relates to a method -- and an apparatus for manufacture of cylindrical rotor structures for moisture and/or heat exchangers.
Still more particularly the invention relates to a method of manufacturing a rotor for a moisture and/or heat - exchanger having a molsture and/or heat exchanging mass of alternately plane and corrugated layers with the corruga-tlons extending substantially axially to form a great number ;~ji of axial, fine channels, and in which method the rotor is built up by alternately plane and corrugated layers being .; assembled and fixed together and thereafter wound up to a `, substantially cylindrical rotor structure.
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~i The invention relates also to an apparatus for manu-, .
facture of the rotor structure in consideration.
Background of the Invention .::. .
In the manufacture of rotors by the method outlined .,;,, above the fixing together of the layers is effected by apply-. ing glue preferably to the corrugation ridges of the .~ corrugated layer before the corrugated and the plane layers :. .
.~ are brought together to be combined by gluing to a coherent . , .
strip. Also the fixing together of the turns of winding of ~; the rotor is effected by gluing. The glue type which is used ,',.1 ::' ., .....
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,, ., a3~St;4 has a relatively long duralion of harden-ing or solidifica-tion o-f up -to 2~ hours. This causes prob1ems for the manu-facture of the rotor, since an undesired displacement easily may occur between -the layers. This holds true especially when the layers are made of aluminium and very -thin such as less than 100 microns, since the displacement which is due to :................ stretching of the layers results in deviations from the :.~ geometric -form aimed at for the finished rotor structure, ~ especially of the fine channels thereof Also transportation and storage of the rotor is rendered difficult or impossible during the hardening and solidification duration of the glue.
One main object of the invention is to provide a method which overcomes the aforestated difficulties in the manufac-ture of the rotor of the type in consideration due to the relatively long duration of the solidification of the glue.
- Another main object of the invention is to provide an .,~, .
apparatus for carrying out the method of the invention for .. manufacture of the rotor of the type in consideration in :
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~. perfect geometric form.
`.Y Short Description of the Draw~ngs ... .
~ Further objects and advantages of the invention will :
~: become apparent from the following description considered in connection with the accompanying drawing which form part ; of this specification and of which:-.. Fig. 1 is a diagrammatic side view of a preferred ;
~. apparatus -for carrying out the method of the .invention, and ,.: .
.~ Fig. 2 is a view following line Il-II in Fig. 1.
:. . Detailed Description of the Preferred Embodiment ~ - 3 -.; .
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Referring now to the drawin~s and especially the embodiment shown in Fig. 1~ two thin sheets or webs 10, 12 are unrolled from storage rolls 11 and 13, respectively.
The thin sheets 10, 12 of which the rotor is to be manu--factured, may in -the illustrated embodiment be of metal, such as aluminium, or some suitable plastic material, but may even be of other material, such as asbestos or cellu-lose paper, or other similar materials with which the afore-mentioned problems may arise. If the rotor shall serve for transfer of moisture the webs may be impregnated or provided with a hygroscopic substance, such as lithium chloride, or a solid sorption agent. One of the webs, in the shown example the web or sheet 12, is folded or corru-gated so as later on together with the plane sheet form the channels of the finished rotor. These channels are formed between the corrugated thin sheets and the plane ones and the spacing between the turns of winding of the plane web in the finished rotor is usually less than 3 mms; amounting for example to between 1 and 2 mms, which defines the vertical .-height of the corrugations.
The thin sheet 12 unrolled from the roll 13 is thus fed over a pulley cylinder 14a to a cylinder 14 formed with grooves extending in parallel with the shaft of said cylinder which ~ ~;
cooperates with a cylinder 15 which is formed with similar grooves. The cylinders 14, 15 are positioned relatively to one another so that the projections of the one cylinder fit into the grooves of the cooperating other cylinder with the ~, .

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web or -thin sheet 12 interposed therebetween. In this way the thin sheet 12 will be folded when it passes through the pinch between the cylinders 14 and 15. After the corrugating step the now shaped thin sheet 12 will Follow w;th and about the circumference of the cylinder 15 to the top portion thereoF
where it meets the plane thin sheet 10 fed from the storage roller 11 over a pulley cylinder 16 and a thrust roller 17 the base portion of which is in contact with the cylinder 15 through the interposed thin sheets 10, 12.
The webs or thin sheets 10, 12 when being assembled shall be joined together to a coherent strip 18. This is :
effected by applying glue to the corrugation ridges on that ~ side of the corrugated web 12 which will meet the plane web : 10 at the pinch between the cylinders 15, 17.
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~ l~hen the sheets or webs after assembly are exposed to ~ a traction in the apparatus, especially when the rotor is ,..
built up vertically, it is in upright position by winding up about a horizontal hub the composed strip 18, the sheets are stretched, which especially with very thin sheets, as mentioned in the introductory part ofthis specification~ may result in that the corru~ated sheet is extended and the height of the corrugation reduced and/or that the corrugations are imparted a deFective form.
To eliminate this risk there is applied, according to the invention, firstly a directly sticking glue which so to say siezes directly and instantaneously binds the layers to one another, and secondly a slowly hardening glue which solidi-fies gradually and imparts to the rotor the necessary mechanical strength for th~ intendeo use which strength .

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cannot be produced by any known type of directly sticking glue. The directly sticking glue imparts provisionally to the rotor structure the strength necessary for manufacture proper of the rotor, transportation from the place of manufactllre and storage. The directly glue may in this connection be of the hotmelt adhesive type, i.e. it is melt or liquid in warm state, but solidifies directly on contact with a call surface, such as the aluminium or plastic sheets forming the rotor. The other glue imparting to the finished rotor the required mechanical strength may, for example, be a water-based thermosetting glue which usually has a setting time of about 24 hours.
The hotmelt glue is applied by means of a cylinder 19, the base part of which dips down into a glue vat 20 below the glue surface of the glue contained in the same. Inserted into the glue vat 20 is a heating coil 21 with connection 22 for keeping the glue at a predetermined increased témperature. ~1 ,.`,i . :, ~
The circumference of the cylinder 19 bears with an upper portion against a portion of the circumference of the corru-gated cylinder 15 covered by the corrugated thin sheet 12 so that the hotmelt glue is applied to the thin sheet on that side which shortly thereafter will meet the plane thin sheet 10 (see also Fig. 2). According to the invention the glue is applied to a part only of the corrugated layer 12, in the shown embodiment on the central portion thereof, whereas on either side of the hotmelt glue layer at the edges of the layer 12 two glue strands of the thermosetting glue are . .

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applied by means of -two cylinders or wheels 23, 24. These cylinders dip with their base portion down into glue troughs 25, 26 ~hile they with an upper portion of the circumference bear against a portion of the cylinder 15 over which the corrugated thin sheet is carried.
In this way the plane thin sheets 10 and the corrugated thin sheets 12 when meeting one another are instantaneously given a directly fixed position relative one another, since the hotmelt glue gets ccld and solidifies almost momentarily on contact with the thin sheets which thereafter cannot be dislodged relatively to one another in the followin~ treatment of the composed strip 18. The thermosetting glue imparts after solidification required mechanical strength to the finished rotor as has been described hereinbefore. By carrying out the gluing operation in the described manner with double gluing cylinders 23, 24 and one gluing cylinder 19 which are positioned on different levels three points of pressure against the thin sheet 12 are obtained which is advantageous from the viewpoint of manufacturing. The corrugated thin sheet which follows around with a portion of the circumference of the cylinder 15 normally tends to rise from the cylinder which tendency hitherto has been counteracted by guide rails or fingers (not shown) arranged behind said portion of the circumference of the cylinder and retaining the corrugated thin sheet in the grooves of the cylinder. Because of the broad gluing zones these fingers or guide rails cause incon-.:;
veniencies by glue sticking to and forming clods on the "
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' fingers or guide rails. Thanks -to the described arrangement of the cylinders 19, 23, 2~ the fingers or rails can be dispensed with, the three cylinders have proved to be suffi-cient for retaining the corrugated layer tightly on the cylinder 15. In order to ensure the solidification of the hotmelt glue there may be provided behind the cylinders 15, 17 a cooling zone as is indicated by the cooling device 27 shown with broken lines and which is operated with cold air or the like agent to cool the plane sheet 10. However, this device is optional, since the hotmelt glue has proved normally to be sufficiently cooled for becoming solidified on contact with the cold webs of thin sheet material.
After the gluing step the composed strip 18 is guided over a pulley cylinder 28 and a cylinder 29 at the underside of which a gluing cylinder 30 which is immersed into a glue vat 31 applies glue on the corrugated side of the strip 18 which is averted from the plane side. As the joined strip 18 has quite another strength than the individual sheets 1O~ 12 and thereby the form of the channels is fixed, the previously mentioned stretching occurring in connection with the winding up of the strlp to obtain the deslred cylindrical rotor structure is no longer as harmful as before, nor can it have any effect on the corrugations for which reason the gluing of the rotor when the corrugated and the plane free surfaces of the composed strip 18 meet one another can be effected solely with thermosetting glue of the same kind as.
is applied by the cylinders 23, 24, i.e. that glue which imparts to the finished rotor its mechanical strength.
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However, it is clear if it should prove desirable or necessary that this gluing step can be efFected in the : same manner as with the cylinders 19, 23, 24. The winding up of the rotor is effected in a manner known in the art, For which reason it is not shown or described here in more - detail.
The elements oF the described apparatus for applica-tion of glue, guiding of the thin sheets and Forming the composed strip etc. can be given some o-ther form than the shown ones.
- : blhile one more or less specific embodiment of the invention has been sh-own and described, it is to be under-. stood that this is for purpose of illustration only, and -: that the invention is not to be llmited thereby, but its .~ scope is to be determined by the appended claims.
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Claims

THE EMBODIMENTS OF THE INVENTION FOR WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In the method of producing a thermodynamic exchanger rotor from a bi-layered strip of superposed slat and continuously cor-rugated thin sheet material which is formed into a cellular struc-ture composed of alternating flat and corrugated layers forming a maze of channels through which streams of fluid media are passed in thermodynamic exchange with one another, the improvement char-acterized by the steps of:
a) advancing continuously a first flat strip of sheet material between a pair of corrugating rollers to a winding sta-tion;
b) applying at least one line of rapidly-hardening hot ad-hesive to the nodes of the resultant corrugations upon emergence of the strip from between the rollers;
c) subsequently applying a line of slow-hardening adhes-ive adjacent said line of rapidly-hardening adhesive during the further advancement of the corrugated strip; and d) advancing continuously a second flat strip of sheet material into contact with the thus adhesive-treated nodes of the corrugations to cause said flat strip to adhere upon contact along said line of rapidly-hardening adhesive to form an initially stabilized bi-layered strip and to allow said slow-hardening ad-hesive to set and impart to the bi-layered strip the required me-chanical strength.

2. The method according to Claim 1, in which a line of slow-hardening adhesive is applied to the nodes of the bi-layered strip on the side obverse to said second flat strip prior to the form-ing operation.

3. The method according to Claim 1, in which said initially formed bi-layered strip is cooled to solidify the rapidly-harden-ing hot adhesive.

4. In an apparatus for producing a thermodynamic exchanger rotor from a bi-layered strip of superposed flat and continuously corrugated thin sheet material which is formed into a cellular structure composed of alternating flat and corrugated layers form-ing a maze of channels through which streams of fluid media are passed in thermodynamic exchange with one another, the improvement characterized by:
a) means for continuously advancing a first flat strip of sheet material from a supply source between a pair of intermesh-ing corrugating rollers to a forming station;
b) means for applying a line of rapidly-hardening hot ad-hesive to the nodes of the resultant corrugations along at least one zone upon emergence of said strip from between the rollers;
c) means for subsequently applying a line of slow-harden-ing adhesive adjacent the said zone of rapidly-hardening adhes-ive during the further advancement of said strip;
d) means for continuously advancing a second flat strip of sheet material from a source of supply to said forming station in contact with the thus adhesive-treated nodes of said corru-gations to cause said second strip to adhere upon contact along said zone of rapidly-hardening adhesive to form an initially sta-bilized bi-layered strip while allowing the line of slow-hardening adhesive to set and impart to the bi-layered strip the required mechanical strength.

5. Apparatus according to Claim 4, having means for applying an additional line of slow-hardening adhesive to the nodes of the corrugations on the side obverse to the second flat strip.

6. Apparatus according to Claim 4, having means for cooling the initially stabilized bi-layered strip.