AU8021587A

AU8021587A - Method and means for combined thermal and acoustic insulation

Info

Publication number: AU8021587A
Application number: AU80215/87A
Authority: AU
Inventors: Michael G. May
Original assignee: May M G
Current assignee: May Mg
Priority date: 1986-09-10
Filing date: 1987-08-26
Publication date: 1988-04-07
Also published as: CN87106284A; WO1988002051A1

Description

METHOD AND MEANS FOR COMB I NED THERMAL AND ACOUST I C I NSULATION

There is a need for greatly improved thermal insulation means for appl ication to large area structures such as buildings , tanks , containers and the l ike. Present insulation materials permit excessive heat losses , requiring large expenditures for energy supply , air conditioning , refrigeration , etc. I mproved insulation will reduce energy losses and avoid energy-associated air pol lution , while reducing costs . Existing thermal insulation systems for buildings do not provide adequate sound attenuation , thus external sounds cause excessive and , for instance , unacceptable noise inside a building .

It is the primary object of this invention to provide a method and means for insulating buildings , and other objects with a combined thermal and acoustical insulation system which will reduce thermal heat transfer and attenuate sound waves more effectively and economically than existing methods and apparatus .

It is a further object of the invention to make it possible to reduce heat losses and noise transmission to minimum values by a method and apparatus which is practical and economical for use with large structures , by the use of multiple modular panels which are vacuum-insulated by one or more vacuum generating devices .

Hence, the invention discloses a combination of steps so as to provide extremely good performance in relation to the combined requirements , including low-cost production , low maintenance cost, high thermal insulation effect, high noise attenuation , and lower cooling or heating energy consumption , with reduced energy costs and related pol lution consequences.

It is not the inventor's intention to describe all possible embodiments of his invention or to specify in detail every one of the principles underlying it. Here, the inventor sets forth , at least substantially, in fully adequate terms , a preferred embodiment and one that will work effectively. Furthermore, the inventor reveals his invention as a new and useful combination without limitation on details of the individual elements making up that combination .

Additionally, detailed descriptions of components , as for example, pumps, valves , pipe means, or known electronic circuits, etc. , are not included because such elements are well-known by those skilled in the art.

The described method is 'applicable for a wide variety of objects and related design requirements , as for instance:

a) container for freight of fresh fruit or vegetables , meat, etc. , on truck or railroad or even a self-contained stationary receptacle;

b) wall elements and window elements for buildings;

c) tanks or other containers for fluid matter, as for instance, heavy oil requiring higher than ambient temperature which is , for instance, required for easier pumping ;

d) various purposes requiring excellent thermal insulation .

It is a particular advantage of the invention to provide means for coordinated supply of vacuum to two or more correlated insulation panels or systems , as for example: a1 ) a railroad train comprising more than one container as mentioned above;

b1) a multitude of wail or window means, which form a building;

d ) a multitude of such buildings;

dl) a multitude of refrigerator shells in an apartment building or condominium, etc.

Figure 1 shows schematically in cross-sectional view, an embodiment according to the invention, and

Figure 2 shows in perspective an array of a preferred multiple arrangement and

Figure 3 shows schematically in cross-section a type of valve used and

Figure 4, 4', 4" show particular shapes of ends of such elements and

Figure 5 shows schematically in cross-section another embodiment of this invention and

Figure 6 shows a further assembly of contiguous bodies adapted to be connected to a vacuum generating means.

In Figure 1, an assembly of a sealed unit is schematically shown. Two relatively thin sheets of essentially gas tight material, e.g., transparent or otherwise, window glass or metallic sheets, etc., 1 and 1 ', are affixed in spaced parallel relation by spacing means 2 and sealed to one another by an appropriate compound 4 as known per se, and these compounds may be made of any well-known synthetic or metallic character. In the cross-sectional view of Figure 1, there is shown as an example, only one of a plurality of spacer elements 2, which comprise a plurality of predetermined spaced heat flow barrier 2' . Such means , which restricts the col lapse of the paral lel spaced sheets, are preferably foreseen . These barrier means are preferably made out of low heat flow conductive material as, for example, glass , ceramics , plastics , elastomers or the like. A further additional function , embodied by the spacer elements, due to an elastic or visoelastic properties , as schematically shown by such a material designed in Figure 1 by 2" , is to prevent long range transmission of vibrations and thereby act to dampen sound or sound attenuation .

A conduit 3 is also shown in the drawing and is affixed in a gas tight manner, such as to enable evacuation , at least in part, of the space comprised within said surfaces 1 and 1 ' . A vacuum generating device 7 is shown in simplified form and not in greater detail since it is known in the prior art. Such devices are utilized in order to be able to evacuate and maintain the vacuum in the space between the parallel sheets within a predetermined range^'. A pressure sensor means which is provided wfth filter and drying means and related control means are denoted by the numeral 6. An external power supply is shown by arrow 8 and feed back control between the pressure sensors 6 and the pump 7 are shown by arrow 9.

It is understood that such elements usually will comprise fixation or attachment means not explicitly shown .

It is also to be understood that the filter-drying means 6 further may comprise vapor absorbing means as is well-known in vacuum technology .

In Figure 2 , a preferred combination of a multitude 100 , 100' , 1 00" etc. , of such thermal barrier means or insulating means, as earlier described , are arranged in substantial geometrical correlation to each other as depicted in this perspective view . Preferrably transparent material is here used to form each of said insulating elements so as to allow light to penetrate, for example through the exterior walls which comprises a series of windows of an office building . Openings , such as doors for entrances and exits for ingress and egress of people , air conduits for climatisation , and merchandises etc. , are not shown but are known to be necessary in such constructions .

As is clearly shown in Figure 2 , a multitude of highly efficient low-cost transparent heat flow barriers can be realized and interconnected easily and at surprisingly low cost, by sharing a common vacuum generating means .

The maintenance of a vacuum requires extremely low power. I n many instances , such a building will yield residual solar heat energy which will enable an inexpensive supply of supplemental energy to heat the building .

A particular phenomena is further to be expected in the fact that through very large surfaces , after primary evacuation , gases of smal l atomic and/or molecular dimensions wil l diffuse into the -evacuated space. It is hence foreseeable that at the exit of the vacuum pump , for example, helium and other thin gases may be obtained , and after separation of the gases in a known manner, such gaseous matter may be utilized .

Preferably automatic valve means 40 are connected to each sealed chamber respectively space confined between the parallel sheets and these valve means are all connected by suitable piping to thereby provide a unitary structure such as depicted in Figure 2. Additional ly , the valve means are l istable check-valve means comprising a means for sensing a sudden increase in undesirable mass flow of essentially gaseous matter which flows toward the vacuum pump means , and upon sensing such mass flow, this valve is designed so that it will move into and remain in a "closed" position thus deactivating the leaking element or elements and thereby prevent loss of vacuum on al l remaining elements . It is furthermore a preferred arrangement in the event of the use of a material having a transparent character to deposit, in per se known and accurate manner , either on the interior or exterior surface, or both surfaces , at least one essentially transparent layer 10 , 10' or 10" of such a material that will provide for controllable polarization of light transmission therethrough. This is realized , for instance , in a transparent shield which is already used for protection of human eyes while welding by arc or plasma means, etc. The required electronic power supply, as well as its control , are known and hence indicated schematically in Figure 1 by arrows 1 1 , 1 1 ' , 1 1 " . With such an arrangement, the intensity of light which passes through such windows can easily be controlled .

A further preferred embodiment contemplates an arrangement wherein instead of applying material having transparent characteristics to the windows, solar cell power generating devices may be provided in these sealed chambers or at least in zones where light transmission is not desired.^" In this way, a facade of a building may be economically constructed by basically standardized shaped elements for later assembly in a unitized manner, while still , in a very economic overall concept, solar energy is made available for power generation . Such photovoltaic solar cell power generating panels, which are basically known , are denoted in figure 1 by further dash dotted lines as at 12 , 12', the interconnection of such an assemblage, not being shown , for it is well known to those skilled in the art.

Obviously, as already mentioned previously, several such insulation panel elements may be supported by related components as shown by 15 and joined together, for example, by an elastomer sealing material as shown by 14. Component 15 may, as is well known , be supported again in a floor 5 , for instance a concrete floor.

In Figure 3 , a first valve body 54, comprises means provided with an orifice. This valve body is affixed in a predetermined manner to another valve body52 comprising a passage 53. A plunger or stepped piston-like element 50 is slideably arranged within said valve body 52 and comprises preferably on each side an elastic seal means 57 , 58 , as for example a rubber-like material appropriate for high vacuum technology . A spring means 51 or the l ike, as for example means generating a force , as for example a magnetic force, having preferably a rather flat spring ratio is arranged such as to provide a relatively small force on said plunger causing thereby the closing of the orifice of passage 55 which is connected to a hollow space wherein a vacuum is deemed to be substantial ly restored periodical ly .

Upon connection of a vacuum onto passage 53 , once the hollow space is evacuated , the valve will close and remain closed even if the vacuum should be disconnected in pipe 53. The evacuated space and hence the whole insulating unit may be translocated in an evacuated condition for quite a while, before diffusion-originated losses of vacuum inside said unit collapses toward undesirable values .

Said plunger further "having a^' cross-sectional area such that the difference between the cross-sectional area of said valve means 52 , surrounding said plunger 50, is definitely smaller, as shown by free gap 56 , than the cross-sectional area of pipes 55 or 53. Hence , should one evacuated unit be destroyed by some incident or have any undesired leak , the plunger 50 is pushed by mass flow towards the orifice of conduit 53 and closes the latter.

In Figure 4, there is shown in a schematic cross-sectional view another assembly of juxtaposed window portions 61 and 62 which are made available where desired to prevent seepage of water between the oppositely disposed horizontal edge portions . It is a well-known fact that because of capillary action liquid can find entrance between sealed surfaces that are believed to be free of leakage. The design of the juxtaposed edges of the windows or similar shaping is to prevent penetration of water between the window elements, hence preventing any risk of window fracture or breakage by ice forming adjacent to window portions 61 or 62 or around the spandrel 63. The composition of 64 which is applied to the spandrel 63 may be foreseen to be a hard elastic element, whereas 65 may be a softer elastic filler, such as a common silicone type elastomer frequently used to seal panels or windows into a framework. Other self-explanatory variations are shown in Figures 4' and 4" .

I n many cases , the objective of insulation comprises implicitely a cooling or heating surface inside such containers composed by such elements as described above, ft is therefore a further objective of the invention to combine such a desired effect in a cost-effective manner as revealed herein .

As is clearly shown in Figure 5 , it is a further object of the invention to provide another layer 72 which is positioned in spaced relationship to the sheets 71 and 71 ' and sealed as at 73 inwardly of these aforesaid layers. This additional layer 72 may be provided with a sealed aperture 82^* through which the previously described conduit 3 is adapted to extend. The layer 72 is equipped with inlet and outlet conduits.74 and 75 by means of which a second hollow space provides for a flow of an energy-transporting fluid. The conduits 74 and 75 may be secured in apertures in layer 72 in any suitable manner. Circulating means not shown to be known per se may circulate heat carrying transportable matter. Of course, preferably more than one of such elements are interconnected with each other to form the circulation means.

A more particular application of the present invention can be realized for positive or negative heat carrier pipe means as for transport of heating or cooling flowable materials , as for example gases or fluids. In such a case, two surfaces , substantially parallel to each other are an inner conduit surface, enveloped in spaced relationship by an outer surface, the space in between these two surfaces being subjected to a predetermined and at least periodically regenerated vacuum, comparable to the earlier revealed method . I n Figure 6 there is shown schematical ly a cross-sectional view of a further improved embodiment of this invention . An inner pipe T for conveying products is arranged in spaced relationship within pipe 1 , the spacing being created , for instance, by spacing elements 2 . The enclosed and sealed space in between said two surfaces is connected preferably via control means 40 to a vacuum generating source not shown in this Figure. Any type of leakage or magnitude thereof wi ll be determinable precisely for example at the exit of the vacuum pump means .

In general , undesirable heat loss , noise transfer, condensation problems , etc. , are successful ly dealt with in a cost-benefit energy consumption and air-pollution reducing level close to the optimum.

The foregoing relates to preferred exemplary embodiments of the invention , it being understood that other variants and embodiments thereof are possible withi-n the spirit and scope of the invention , the latter being defined by the appended claim .

Claims

1 . A method for high efficiency thermal and acoustic insulation comprising at least two sheets of substantially gas tight material , said sheets being arranged in substantially parallel relation to each other and further comprising a predetermined space therebetween , said at least two sheets being affixed and sealed to each other to form a substantially hollow-space insulating unit, characterized by :

- having at least one permanent orifice means to allow for at least periodic evacuation of said hollow space, and a bistable check valve means adapted to evacuate sajd hollow space..

2. A method according to claim 1 further comprising the step of:

- interconnecting at least two of said hollow spaces adjacent to said bistable check valve means .

3. A self-contained sealed element adapted to be assembled in seriatum to form a unitary, substantially closed body , each said self-contained sealed element comprising at least two sheets of

-substantially gas tight material , said sheets being arranged in a substantially parallel manner relative to each other and further including a predetermined space therebetween , at least one of sard two sheets provided with means defining an aperture therein and flow control valve means including a bistable check valve means interconnected between a vacuum generating means and said self-contained sealed element. 4. A method for providing a high efficiency thermal and acoustic insulation , comprising the steps of:

- providing at least two sheets of substantially gas tight material , said sheets being arranged in substantial ly paral lel relationship to each other to define a hollow space therebetween ,

- affixing and sealing said theets to each other to form a hollow insulating unit wherein said hollow space is substantially enclosed ,

- providing at each said hollow space of said insulating unit at least one permanent orifice means connected to an evacuation conduit to allow for evacuation of said hollow space via said evacuation conduit,

- providing a bistable check valve means in said evacuation conduit, whereby there are defined inner and outer portions of said evacuation conduit which are separated from each other by said bistable check valve means , said inner portion being located between said orifice means and said bistable check valve means , said outer portion being located opposite to said orifice means in respect of said bistable check valve means ,

- providing at least two of said insulating units ,

- interconnecting said outer portions each of a respective one of said insulating units, and

- generating at least periodically a vacuum within a predetermined range by means of a vacuum generating means and applying said vacuum to said evacuation conduit.

5. A method according to claim 4, further comprising the step of: - providing a control means disposed on at feast one of said outer portions of a respective one of said evacuation conduits between said bistable check valve means and said vacuum generating means.

6. A method according to claim 4 , wherein each of said sheets is substantially transparent to light.

7. A method according to claim 6 , further comprising the step of: "

- providing controllable light polarization means on at least one surface of each of said sheets .

8. A method according to claim 4, wherein each of said sheets has a respective inner surface disposed in confronting relationship to the inner surface of at least another one of said sheets , further comprising the step of: ^• .

- providing at least at a zone of said inner surface of one of said sheets a solar-ceil photovolatic device for generating electrical energy.

9. A method according to claim 4, further comprising the step of:

- providing at least one spacing means between said sheets , and

- providing structural connection between said spacing means and said sheets to thereby reduce mechanical stress of said sheets due to evacuation of said hollow space.

10. A method according to claim 9 , wherein said spacing means is made of material having low thermal conductivity and elastic or viscoelastic properties to thereby reduce transmission of sound and vibration between said sheets. 1 . A method according to claim 4 , further comprising the step of :

- providing at least one further sheet in substantial ly contiguous relationship with a predetermined one of said two sheets , said further sheet being arranged in substantial ly parallel relationship to said two sheets to define a furtherhol low space between said further sheet and the predetermined one of said two sheets ,

- affixing and seal ing said further sheet to said predetermined one of said two sheets to form a hollow insulating unit wherein both said hol low space and said furtherhol low space are substantially enclosed ,

- said insulating unit comprising inlet and outlet means arranged at a respective orifice means of said further hol low space to provide for flow of a heat energy transporting fluid through said further hol low space.

2. A self-contained element comprising a plurality of insulating units adapted to be assembled adjacent to each other to form a unitary, substantial ly closed body , each self-contained element unit comprising :

- at least two sheets of substantially gas tight material , said sheets being arranged in substantially parallel relationship to each other to define a hol low space therebetween and being affixed and sealed to each other to form a hol low insulating unit wherein said hollow space is substantial ly enclosed ,

- each said insulating unit being provided at each said hol low space with at least one permanent orifice means connected to an evacuation conduit to allow for evacuation of said hollow space via said evacuation conduit. - said evacuation conduit being provided with a bistable check valve means , whereby there are defined inner and outer portions of said evacuation conduit which are separated from each other by said bistable check valve means , said inner portion being located between said orifice means and said bistable check valve means, said outer portion being located opposite to said orifice in respect of said bistable check valve means ,

- means for interconnecting said outer portions each of a respective one of said insulating units , and

- means for connecting said evacuation conduit to a vacuum generating means.

13. A self-contained insulating unit according to claim 12 , further comprising a control means arranged on at feast one of said outer portions of a respective one of said evacuation conduits betwe _*en said bistable check valve means and said means for connecting said evacuation conduit to a vacuum generating means.

14. A self-contained insulating unit according to claim 12 , further comprising at least one further sheet disposed in substantially contiguous relationship with a predetermined one of said two sheets , said further sheet being arranged in substantially parallel relationship to said two sheets to define a further hollow space between said further sheet and said predetermined one of said two sheets ,

- said insulating unit comprising inlet and outlet means arranged at a respective orifice means of said further hollow space to provide for flow of a heat energy transporting fluid through said further hollow space.

15. A self-contained insulating unit according to claim 12, further comprising at least one spacing means disposed between said sheets and structural ly connected therewith to thereby reduce mechanical stress of said sheets due to evacuation of said hol low space.

6. A self-contained insulating unit according to claim 1 5 , wherein said spacing means is made of material having low thermal conductivity and elastic or viscoelastic properties to thereby reduce transmission of sound and vibration between said sheets .