WO2010144032A1

WO2010144032A1 - Rotor for a rotating heat exchanger and a method for manufacturing such rotor

Info

Publication number: WO2010144032A1
Application number: PCT/SE2010/050603
Authority: WO
Inventors: Mikael Swanteson
Original assignee: Heatex Ab
Priority date: 2009-06-10
Filing date: 2010-06-02
Publication date: 2010-12-16
Also published as: SE533839C2; SE0950440A1

Abstract

The present invention refers to a rotor (1) of a rotating heat exchanger having an essential cylindrical shape and comprising at least two sections (2), arranged around an axis (3) and being provided with at least one peripheral element (5), at least one radial element (4), located between adjacent sections (2), and clamping means (6), for fastening the at least two sections (2) of the rotor (1). According to the invention at least one clamping means (6), connected to the radial element (4) and to the peripheral elements (5) of said adjacent sections, simultaneously applies tension to said radial element (4) and said peripheral elements (5) when tightened, whereby the peripheral elements (5) being pulled against each other by sliding along an inclined surface (10a, 10b).

Description

ROTOR FOR A ROTATING HEAT EXCHANGER AND A METHOD FOR MANUFACTURING SUCH ROTOR

Field of the Invention

The present invention relates to a rotor of a rotating heat exchanger having an essential cylindrical shape and comprising at least two sections, arranged around an axis and being provided with at least one peripheral element, at least one radial element, located between adjacent sections, and clamping means, for fastening the at least two sections of the rotor.

Background of the Invention

The rotating heat exchangers are mainly used to recover heat in exhaust air leaving a ventilation system of a building, but are also, for instance, used in systems for climate control, dehumidification and humidification. There are several regenerative rotating heat exchangers on the market. Rotating heat exchangers come in a large variety of sizes, having air handling capacities of typically 500 m³/h to 100 000 m³/h. The largest rotating heat exchangers can have diameters of 4-6 m.

In order to be able to transport large rotating heat exchangers, typically above 2.5 m, the rotors are cut into sections in the shape of a pie pieces. The sections can then be individually transported to the site where the heat exchanger is about to be mounted. At the mounting site the sections are put together to form a rotor.

Radial elements in form of spokes, for example, made of flat bar iron are placed between each section. In addition, the outer periphery of each section is covered by a peripheral element, for instance in form of a metal band or flexible metal sheet. The radial elements and the peripheral elements are then connected and locked to each other in order to lock all sections of the rotor together.

One connection solution is shown in US 6 422 299, where the radial element consists of I-beam structures which are fitted, at the periphery of the rotor, between the ends of two different peripheral elements, here referred to as rim joints. The joints give both radial and tangential tractive forces in the rotor. The tension of the peripheral elements and the radial elements are set in multiple steps.

A problem with variants using radial elements and peripheral elements connected together using individual joints, is that mounting requires separate adjustment of the radial elements and the peripheral elements, respectively. An increase in radial element tension often leads to a reduction of the peripheral element tension. In order to get the correct tension in both the radial elements and peripheral elements, stepwise adjustment is required. The tension is therefore difficult to check. In worst case, there can even be compressive forces in either the radial elements or the peripheral elements, which can lead to mechanical instability of the rotor.

Summary of the Invention

It is an object of the present invention to mitigate the above problems, and to provide a rotor, for use in rotary heat exchangers, wherein an increase in radial element tension will lead to an increase in peripheral element tension.

According to a first aspect of the present invention, these objects are achieved by that at least one clamping means, connected to the radial element and to the peripheral elements of said adjacent sections, simultaneously applies tension to said radial element and said peripheral elements when tightened, whereby the peripheral elements being pulled against each other by sliding along an inclined surface. By this, the mounting will be considerably simplified since only one clamping action will give a controlled and predictable tension in both the radial element and the peripheral elements.

The clamping means is fastened to the radial element and being connected to at least two peripheral elements. Two, or more, peripheral elements make the rotor more stable since they function as additional support on the periphery of the rotor.

The fastening means can comprise a tensioning block and a tightening device. By this, a very simple solution for the clamping action is achieved using standard components. The radial element has a threaded portion, located at its external end, related to the centre axis of the rotor. This is yet another simple solution for fastening the tensioning block on the radial elements.

The peripheral element covers, at least partly, the periphery of said section. This increases the stability of the rotor.

The peripheral element is provided with a wedge shaped protrusion arranged at least at one end of the peripheral element, said protrusion having an inclined surface, which being intended to engage into the tensioning block. This is a fast and simple way of locking the peripheral elements into the tensioning block, as no other fastening means are needed.

The peripheral element can as an alternative have one end of the peripheral element bent outwards from said periphery, in a radial direction, to form an inclined surface, which being intended to engage into said tensioning block. This is also a fast and simple way of locking the peripheral elements into the tensioning block, as no other fastening means are needed. This solution is also requires less material and labour.

Another aspect of the invention is a method for manufacturing a rotor for a rotating heat exchanger, wherein the rotor is divided into at least two sections, at least one radial element is arranged between each two adjacent sections, and a clamping means is provided, wherein when tightening the clamping means, tension being applied simultaneously to at least said radial element and to a periphery of at least two adjacent sections, whereby the peripheral elements being pulled against each other by sliding along an inclined surface. Hereby, mounting will be considerably simplified since only one clamping action will give a controlled and predictable tension in both the radial elements and the peripheral elements.

Brief Description of the Drawings

This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing a currently preferred embodiment of the invention.

Figure 1 shows a schematically partial side view of a rotor according to the present invention. Figure 2 shows an enlarge cross section view of two embodiments of a clamping means of the rotor according to figure 1.

Figure 3 shows a schematically view from above of the clamping means of the rotor according to figure 1.

Detailed Description

Figure 1 shows two sections 2 of a rotor 1 according to the present invention. A number of such sections 2 are mounted on a circular centre axis 3 to form the rotor 1 in an essentially cylindrical shape. The rotor 1 having radial elements 4 located between two adjacent sections 2 and a number of peripheral elements 5 located towards a periphery 7 of the rotor 1. A clamping means 6 connected to the radial element 4 and to the peripheral elements 5 being used for holding the sections 2 together.

The rotor 1 itself is made of alternating layers of corrugated and flat aluminium sheets (not shown in detail) suitable for heat transfer. The rotor 1 is created by winding one corrugated and one flat aluminium sheet around the axis 3. This means that every second layer is a flat sheet and every second layer is a corrugated sheet. The two sheets form a spiral (not shown in detail) building up the rotor 1. The sections 2 are then created by simply cutting up the rotor 1 , into pie-shaped sections 2. Each section 2 is self-supporting and no additional elements are needed in order to maintain the shape of the sections 2.

Thus, the rotor 1 consists of at least two pie-shaped sections 2, mounted to the circular centre axis 3, forming an essential cylindrical rotor 1. The number of pie-shaped sections 2 depends on the size of the rotor 1. A smaller rotor 1 having a diameter up to 2.5 m, as an example, may be divided in up to six pie-shaped sections 2. A larger rotor 1 having a diameter of 6,0 m, as an example, may have twelve pie-shaped sections 2 and each such section 2 may also be divided into several elements (not showed) in the radial direction of the rotor 1. In the embodiment disclosed in figure 1 the rotor 1 having eight pie-shaped sections 2. At least one radial element 4 is mounted between adjacent sections 2, the radial element 4 having a length of at least a majority of the radial length of the sections 2. The radial element 4 is mounted, at one end, to the centre axis 3. The radial element 4 extends, from the centre axis 3, in a radial direction towards the outer periphery 7 of the rotor 1. Clamping means 6 are applied in order to connect the radial element 4 to the peripheral elements 5. The peripheral element 5 is shaped as an arch in order to abut the outer periphery 7 of the rotor 1. Preferably, the peripheral element 5 covers at least partly the periphery 7 of a section 2.

As appear from figure 2, the radial element 4 is provided with one or several threaded portions 9, fastened in relation to the centre axis 3 of the rotor 1 , to an exterior end 8 of the radial element 4 by welding or in other known manner. Further, the peripheral elements 5 are, in one embodiment of the invention, provided with a bent end portion to form an outwardly inclined surface 10a or in another embodiment of the invention, provided with wedge shaped protrusions 11 , having an inclined surface 10b, and being fastened at the end of each peripheral element 5, i.e. where the peripheral elements 5 meet the radial elements 4. The clamping means 6 comprising a tension block 12, having an inner conical surface 13 shaped to match the inclined surface 10a and 10b on the peripheral elements 5 or the protrusions 11. The tension block 12 is intended to lock the peripheral elements 5, at assembly of the radial elements 4 to the rotor 1 , and at tightening of the clamping means 6 the inclined surface 10a or 10b sliding against the conical surface 13, whereby the peripheral elements being pulled against each other. A tightening device 14, preferably a screw or a bolt and nut, going through an opening 15 in the tension block 12, is screwed into the threaded portion 9 of the radial element 4. When the tightening device 14 is tightened the tension block 12 is pulled down towards the centre of the rotor 1 and sliding along the inclined surface 10a or 10b, tightening the radial elements 4 and at the same time pulling two adjacent peripheral elements 5 together. Thus, at least one clamping means 6, connected to the radial element 4 and to the peripheral elements 5 of said adjacent sections, will upon tightening simultaneously applies tension to said radial element 4 and said peripheral elements 5.

As appear from figure 3 each radial element 4 have a separate tension block 12 located close to each side of the rotor 1 , but it is also possible to use only one tension block, which extends across the width of the rotor 1 , and having a centrally located screw. Also, the inclined surface 10a or 10b may extend across the entire width of the rotor 1 or at discrete positions preferably located close to each side of the rotor 1. The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the tightening device must not be a screw or a threaded means. Various kinds of quick locks can advantageously be utilized. It is, for instance, also possible to let the outer portion of the radial element protrude through the tension block, and for instance use a nut to tighten the radial element and thus also the peripheral elements.

Various kinds of fastening means can of course be used without departing from the idea of the invention, as long as the radial elements and peripheral elements are tensioned simultaneously. It is of course also possible to use various means instead of the peripheral elements. For instance, the periphery of each section can be made even more rigid in order to be able to handle the tension produced by the tension block. It is, for instance, also possible to use wires instead of bands.

Claims

1. A rotor (1) of a rotating heat exchanger having an essential cylindrical shape and comprising at least two sections (2), arranged around an axis (3) and being provided with at least one peripheral element (5), at least one radial element (4), located between adjacent sections (2), and clamping means (6), for fastening the at least two sections (2) of the rotor (1 ), characterised in that at least one clamping means (6), connected to the radial element (4) and to the peripheral elements (5) of said adjacent sections, simultaneously applies tension to said radial element (4) and said peripheral elements (5) when tightened, whereby the peripheral elements (5) being pulled against each other by sliding along an inclined surface (10a, 10b).

2. A rotor (1 ) according to claim ^characterised in that clamping means (6) is fastened to the radial element (4).

3. A rotor (1 ) according to claim ^characterised in that the clamping means (6) comprises a tensioning block (12) and a tightening device (14).

4. A rotor (1 ) according to claim ^characterised in that the radial element (4) having a threaded portion (9), located at its external end (8), related to the centre axis (3) of the rotor (1 ).

5. A rotor (1 ) according to claim ^characterised in that the peripheral element (5) covers, at least partly, the periphery (7) of said section (2).

6. A rotor (1 ) according to claim 3, characterised in that the peripheral element (5) is provided with a wedge shaped protrusion (11 ) arranged at least at one end of the peripheral element (5), said protrusion (11) having an inclined surface (10b), which being intended to engage into said tensioning block (12).

7. A rotor (1 ) according to claim 3, characterised in that at least one end portion of the peripheral element (5) is bent outwards from said periphery (7), in a radial direction, to form an inclined surface (10a), which being intended to engage into said tensioning block (12).

8. A method for manufacturing a rotor (1) for a rotating heat exchanger, wherein said rotor (1) is divided into at least two sections (2), at least one radial element (4) is arranged between each two adjacent sections (2), and a clamping means (6) is provided, characterised in that when tightening the clamping means (6), tension being applied simultaneously to at least said radial element (4) and to a periphery of at least two adjacent sections (2), whereby the peripheral elements (5) being pulled against each other by sliding along an inclined surface (10a, 10b).