AU665793B2 - A moulded thermal insulation body - Google Patents

Description

66579

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

S F Ref: 230275 Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Thyssen Nordseewerke GmbH Am Zungenkai 2970 Emden

GERMANY

Ekkehard Nowara Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia A Moulded Thermal Insulation Body The following statement is a full description best method of performing it known to me/us:of this invention, including the 5845/4 l-;i I' a-1i Thermally insulating shaped body for thermal insulation Si The invention relates to a thermally insulating shaped body for thermal -insulation.

The insulation principal of Dewar flasks which relates to the evacuation of a gas tight sealable hollow space, is generally known. Furthermore, the container walls of such containers are usually mirrored, in order to minimise the radiative thermal transfer.

Thermally insulating shaped bodies made on the basis of pressed, microporous thermally insulating material are known from EP-1064006. In some cases the shaped body has been partially or wholly shrouded by a gas tight envelope and the pressure inside of the envelope reduced down to at least 20mbar. Furthermore, it is known to use a composite sheet of a thermoplastic material with a metal layer on one side as the envelope material.

In addition, it is known from DE-2615299 to manufacture a container for such thermally insulating shaped bodies from thin sheet metal and to make the connection between the base and cover sheet by flanged, very thin metal sheets. The same approach is also proposed in DE-3630399.

DE-3108810 concerns an elastically extensible insulation comprising panels with their side surfaces arranged in pairs parallel to each other and from strips of a thermally insulating material which are elastically deformable only in one direction and which are adhesively bonded to each other and to the panels at their contact surfaces.

All previously known thermally insulating shaped bodies have the disadvantage that they are very difficult to manufacture or that the desired pressure and stiffness requirements are not fully met.

It was therefore the object of the invention to overcome these disadvantages and to create a thermally insulating shaped body which is easy to manufacture, but still meets the said requirements.

The object of the invention is satisfied in accordance with claim 1.

The arrangement of the invention whereby the at least two panels are arranged on top of one another with at least one pressure resistant spacer plane provided between any two panels improves the insulation, stability and torsional stiffness of the body.

The spacer plane must be at least as pressure resistant as the respective panels.

To this end, plastic spacer planes in the form of double webbed plates are preferred, where variously formed webbing is proposed. It is however also possible, that the spacer plane be made of perforated honeycomb material. With regard to the convenient evacuability of the thermally insulating shaped body, value is also placed on perforation 'TR of the spacer plane. Such a spacer plane can take up the largest part of the volume of a S thermally insulating shaped body. The supporting webs of such spacer planes should [N:\LIBHH1]0r3j4:ar -2he employed in small numbers, in order to keep the thermal conduction low. An envelope with a reflecting and perforated sheet or a reflective coating can also be fitted here, in order to minimise the radiative contribution to the heat transfer, as was proposed for the panels.

In an embodiment of the inventio. L is proposed that the pressing of the glass microfibres into a panel shaped form tak place without employing bonding material.

One thereby retains a panel which is open-pored, consequently making the evacuation of the thermally insulating shaped body considerably easier. Additionally, with respect to the environmental friendliness, it is noted that the panel without bonding material can be returned in its entirety to the recycling process. It may then be processed so that it finds application in a new insulating body of another spatial form.

In order to maintain an optimisation between stiffness and thermal conductivity, differing diameters and lengths of fibre are expediently used. With this precondition, the glass microfibres should principally have diameters roughly in the range d, =O.txlO0- 3 mm to d 2 =x10- 3 mm.

Correspondingly, the fibre lengths should lie principally between -mm and 6mm. The use of glass microfibres outside of the stated diameter and length ranges is also possible, but leads to a worsening of the stiffness and/or the thermal conduction properties.

To take advantage of the beneficial infra-red reflection properties of reflective sheeting, it is further proposed that the side faces of the panels are fitted with perforated, reflective sheets. The perforation is necessary in order not to lose the advantageous evacuating properties of the thermally insulating shaped body gained from the open-pored nature of its panels.

With the thermally insulating shaped bodies according to the invention, it is possible to manufacture preformed parts in any desired form. Possible forms are panelled areal elements in planar and curved shapes, tubes, integrally constructed boxes etc..

etc..BRIEF DESCRIPTION OF THE DRAWINGS Preferred forms of the present invention will now be described by way of :"example with reference to the accompanying drawings, wherein: Figure 1, depicts a prior art moulded thermal insulation body with one panel only; Figure 2, a moulded thermal insulation body according to the present invention with two panels and an interposed layer of spacer means; and Figure 3, a moulded thermal insulation body according to the present invention with two panels and two interposed layers of spacer means.

[N:\LIEHH]00340:!an -3- I iDETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Equal components are denoted by identical reference numbers in Figures 1 3.

The figures show the moulded thermal insulation body denoted as a whole by 8 and consisting of the envelope 1 with the socket 7 for evacuation, the panel 4, and the perforated, reflecting foil 2 situated between the panel 4 and the envelope 1. The moulded thermal insulation body's 8 end faces of poor thermal conductivity are denoted by 3.

In Figure 2 there are provided two panels 4, 4' between which there is arranged a compression-resistant layer 5 of spacer means comprising spacer members 6. Similarly, a perforated, reflecting foil 9 is provided between the layer 5 of spacer means and the panels 4, In addition to the layer 5 of spacer means, in Figure 3 there is provided still another layer 5' with spacer means comprising spacer members The double layer of spacer means serves to reduce the weight and to add to the rigidity of the moulded thermal insulation body 8.

Ai t i~ [N:\LIBHH100340:Iam e

Claims (7)

1. Thermally insulating shaped body for thermal insulation, comprising: at least two panels made of microporous thermally insulating material of pressure-resistant, baked-out, finely-fibrous glass microfibres, each panel being formed into its panel shape in a compression step by pressing; at least one pressure resistant spacer plane which is provided between each two panels, so that the at least two panels and the at least one pressure resistant spacer plane form a sandwich structure; an envelope which envelopes the sandwich structure and which is evacuable, wherein the envelope is comprised of material of poor thermal conductivity at least at its edge faces at the side edges of the sandwich structure.

2. Thermally insulating shaped body as claimed in claim 1 characterised in that the pressing of the microporous thermally insulating material into their panel shape takes place without the use of a bonding agent.

3. Thermally insulating shaped body as claimed in claim 1 and 2, characterised in that the mic;oporous thermally insulating material is comprised of a mixture of finely fibrous glass microfibres with different diameters and different fibre lengths.

4. Thermally insulating shaped body as claimed in claims 1 to 3, characterised in that the side faces of the panels are fitted with perforated reflecting sheets or a reflective coating.

Thermally insulating shaped body as claimed in one of the preceding claims, characterised in that the at least one pressure resistant spacer plane comprise at least two pressure resistant spacer planes having perforated, facing plates with differently formed webs.

6. Thermally insulating shaped body as claimed in claim 5, characterised in that the at least one pressure resistant spacer plane consists of a perforated honeycomb material.

7. Thermally insulating shaped body substantially as herein described with reference to and as illustrated in the accompanying drawings. DATED this Thirteenth Day of September 1995 Thys4.-Ln Nordseewerke GmbH Patent ttorneys for the Applicant SFWJSON FERGUSON [N:\LIBHH00340:Iam j A Moulded Thermal Insulation Body ABSTRACT A moulded thermal insulation body for thermal insulation, composed of an envelope adapted to be evacuated and filled with a solid, microporous heat-insulating material is characterized in that at least the end faces i. of the envelope are made from a material with poor thermal conductivity, that the microporous heat insulating material is composed of i compression-resistant and annealed thin microglass fibres, and that the thin microglass fibres are compacted by compression to form panels (4) (Figure 1). i I 4 o* o o44 o 0 aI 759z/jrb