CA1085817A

CA1085817A - Rotor for moisture and/or heat exchangers as well as method and apparatus for manufacture thereof

Info

Publication number: CA1085817A
Application number: CA277,931A
Authority: CA
Inventors: Per Norback
Original assignee: Carl Munters AB
Current assignee: Carl Munters AB
Priority date: 1976-05-13
Filing date: 1977-05-09
Publication date: 1980-09-16
Also published as: NO142318C; NO771684L; DE2719992C3; DE2719992B2; GB1567239A; JPS52137747A; NO142318B; FR2351375A1; FR2351375B1; NL7705317A; SE7605472L; SE450166B; DE2719992A1

Abstract

METHOD OF PRODUCING A ROTARY THERMODYNAMIC EXCHANGER This invention relates to a method for producing a rotor or similar body for moisture and/or heat exchangers containing a transferrer mass composed of alternately plane and corrugated layers with the corrugations extending in axial direction so as to form a plurality of axial narrow channels extending from end to ends In order to increase the moisture and/or heat transferring capacity of the exchanger rotor, the continuity of said narrow axial channels is partially interrupted at predetermined places by the corrugaged layer or layers being formed with a plurality of stripshaped portions displaced relatively to one another in the peripheral direction of the rotor for a distance preferably amounting to between one-half and one-third of the individual corrugations. The increase of the resistance to flow in the longitudinal direction of the channels created in this way at the transitions from one strip-shaped portion to the displaced adjacent portion is kept at so low a value that said resistance nowhere falls below the resistance to flow in the direction across said channels.

Description

2 O FIELD OF THE INVENTI ON
This invention relates to a rotatable body for exchangers ; for effecting a change in the physical properties of a gaseous ; medium by interaction with another medium.
More particularly, this invention relates to a rotor or sim-ilar body for moisture and/or heat exchangers, comprising a moistur, ., .

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: . ' , ' , . :, ' ' ~ ' ' .` ' .' ~L~8~i8~7 and/or heat exchanging mass of alternately plane and corrugated layers, the corrugations,extending substantially a~ially so as to form a great number of a~ial narrow channels.
The invention also relates to a method and an apparatus for manu~acture of the product in consideration.
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MAIN OBJECTS OF THE'INVE~TION
One main object of the invention is to provide a rotor or similar body of the stated kind which has substantial capacities of transferring moisture and/or temperature exceeding those of conventional devices so as to involve considerable savings of material in the manufacture of the rotor or similar body.
Another object of the invention is to provide a method by which the rotor or similar body can be manufactured in a highly accurate manner so as to render a product satisfying very high demands on quality and endurance.
- ~ill a furth~r object of the invention is to provide an apparatus for carrying out the method in a reliable manner and permitting easy change in the dimensions of the individual layers formed and assembled in the apparatus to be treated further to take the shape of a rotor or similar body.
S~ORT DES'CRIPTION OF THE ~RAWINGS
Further objects and advantages of the invention will become ,' apparent from the .ollowing description considered in connection with the accompanying drawings which form part of this description and of which~
Fig. 1 is a side ~iew of a rotor made according to ~he in- "' vention~
Fig. 2 is a side view of a fragment of the rotor shown in Fig, 1 in a much enlarged scale and shows the alternately plane and corrugate~ layers of which the rotor--mass is built up.
Fig. 3 is a diagrammatic perspective view of an apparatus for manufacturing of the web composed of corrugated and plane .,:`

~ ~ ~5 ~ ~ 7 layers of w~ich the rotor acco~ding to the invention is built up.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
~eferring now to the drawings and especially to Figs. 1 and 2 ? the rotor shown therein is formed with a hub 10 which contains bearings (not shown) for a sha~t supporting the rotor in a frame.
Between the hub 10 and an outer flange 12, the rotor is filled with a moisture and/or heat exchanging mass composed of thin layers or webs of, e g., asbestos or cellulose paper, metal, such as alum-inium or the like, plastic material or other materials havin~ suit-able properties for the inténded use. If the rotor shall serve for transfer of moisture, the layers are also impregnated or coated with a hygroscopic substance, such as lithium chloride, or a solid sorption agent. When appropriate, the layers are also supplied with suitable additives so that required mechanical strength of the individual layers and of the joining between the same is at-~: tained. Most conveniently, the layers are formed of a plane web 16 and a corrugated web 1~ which are wound up spirally to a cyl-indrical blank. The corrugations extend axially during the wind-ing up operation and thus form thereunder a great number of narrow 2Q channels extending from end to end. The spacing between the turns oE winding of the plane web is preferalby less than S mms., for example, 1 mm. to 3 mms., which thus constitutes the vertical height of the corrugations in the interposed corrugated layer.
According to the invention, the corrugated web 1~ (Fig. 3) comprises a plurality of strips 20, 22, 24 (see also Fig. 2) which are displaced relatively to one another in the longitudinal direction, i~e~, in the circumferential direction of the Einished ;
rotor, in such a manner that the continuity of the narrow chan-nels Eormed by the corrugations is interrupted at the passage 30 between the strips. In this way, the laminary flow of the air passing -through the rotor will be broken up at the transition be- 3 tween the strips of the corrugated layer so that the :Elow profile at the inlet t~ a channel with steep temperature and velocity ~ 3J

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gradient is reformed at each such transition, which improves the transfer capacity of the rotor with respect to both moisture and heat.
Preferably ? the strips are displaced relatively to one another by one-half or one-third of the width of one corrugation or fold length, so that each second or each third layer will be positioned without displacement relative one another. In deter-mining the width of the strips, one must take into consideration that the resistance by too narrow strips 20, 22, 24 may cause the air to change direction. Therefore, one must always see that the flow resistance in the direction across the channels is greater than that in the longitudinal direc~ion of the channei, as other- `~
wise, a tangential flow in zig-zag direction may be produced with-in the rotor, which results in a mixture of inlet air and outlet air, In the preferred embodiment shown in Fig. 3 of an apparatus I for manufacture of the rotor acco~ding to the invention, a planeintegral web 26 is subdivided by means of a number of diagram-matically shown knives 28 over its entire width into a suitable number of strips. By means of two corrugating cylinde~s 30, 32 which consist of a number of toothed cylindrical discs 34, 36 and 38, 40, respectively, the strips are then folded or corrugated by the discs 34, 36 and 38, 40, which are displaced relatively to one another a distance equal to the desired displacement of the strips 20, 22 and 24 in the corrugated web. In order to vary the degree of displacement, the cylinder discs may be rotated relatively to one another on the cylinder shafts 42, 44 and locked in desired position~
After the strips 20, 22 and 24 have been folded or c.orrugated in the nip between the cylinders 30 and 32, and while they still are retained in the grooves of said c~linder 30, a glue is applied to the side averted from the cylinder 30 of the strip portions 20, 22 and 2~ by means of a gluing roller 46 which has one part ~S~L7 of its periphery immersed in a glue vat 48 and anot~er part bear-ing agalnst the strips 20, 22 and 24 positioned on the cylinder 39. The lower part of the cylinder 30 forms a nip together with a pressing roller 52 about which runs a plane layer or web which is unwound from a supply cylinder (not shown) and which in Fig. 3 is denoted 50 and which forms the layer 16 in the finished rotor structure (Fig. 2). By the pressing roller 52, the layer 50 is pressed against the glue-coated nodes of the strips 20, 22 and 24, so that these nodes are fixed onto the plane layer 50 without their relative positions being changed.
Thereafter, the thus-formed bi-layered web is wound into a cylindrical body in l~nown manner, or the flat web may be formed `~
into rotor sectors which thereupon are assembled into a rotor.
After the winding or otherwise forming, the rotor mass is machined by cutting or grinding, so as to impart to its lateral faces the required smooth surface. Especially for large rotors, the rotor mass can also be subdivided into sectors to facilitate transpor-tation, assemblage and exchange of the rotor parts.
Thus, in the finished rotor mass, the plane layer 16 con-stitutes a carrier for the folded or corrugated strips 20~ 22 and 24. By the relative displacement of the strips as described, a considerable improvement of the exchange efficiency is obtained.
It has proved possible to use in a conventional rotor transferrer type, corrugations which have a height of 2.5 rnms., instead of 1.5 mmns., without impairment of efficiency, which results in a saving of 40% of ~he cost of material for the rotor with unchanged thickness of material. ~ith the mentioned corrugation height, the width of the corrugated strips may be from 5 mms. to 20 mms.
It is obvious to an expert in the art that the rotor mass may be built up of parallel plane layers, instead of cylindrically wound layers.
l~hile one more or less specific embodiment of the invention has been shown and described, it is to be ~mderstood that this is for the purpose of elucidation only, and that the invention is not ~s~

to be li~ited thereby, but its scope is to be determined by the appe~ded 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 wheel-like rotor for trans-ferring thermodynamic characteristics between streams of gaseous media composed of a bi-layered web comprising a length of a flat integral sheet defining the thickness of the rotor and supporting a corrugated sheet, which web is formed into a cyl-indrical structure of alternating flat uninterrupted layers and corrugated layers forming a maze of channels extending axially through the cylindrical structure and through which channels the streams of gaseous media are passed in thermodynamic exchange with one another, as the rotor moves cyclically between the streams, the improvement comprising:
a) subdividing the corrugated sheet into a plurality of strips; and b) adhering said strips contiguously across the entire width of said integral flat sheet and along the entire length thereof with the corrugations of contiguous strips being rela-tively offset lengthwise to produce a maze of disaligned inter-rupted channels supported between the uninterrupted flat layers in the formed cylindrical structure and thereby cause the streams of gaseous media to flow in a random pattern through the rotor, with consequent increased heat exchange co-efficient thereof.

2. The method according to Claim 1, in which said strips are offset a distance ranging between one-half and one-third of the space between the nodes of the corrugations.

3. The method according to Claim 1, in which the corru-gated strips are first produced from flat strips severed from a flat sheet and then corrugated and applied in offset fashion to said integral flat sheet.

4. The method according to Claim 1, in which the width of said corrugated strips is calculated so as to create a flow re-sistance in the direction across the channels in the rotor which is greater than the resistance in the longitudinal di-rection of the channels.