EP2795175A1

EP2795175A1 - Wall element and encapsulation for thermal insulation of a vacuum system, and method for the operation thereof

Info

Publication number: EP2795175A1
Application number: EP12794184.7A
Authority: EP
Inventors: Wolfgang Braun
Original assignee: Createc Fischer and Co GmbH
Current assignee: Max Planck Gesellschaft zur Foerderung der Wissenschaften eV
Priority date: 2011-12-21
Filing date: 2012-11-14
Publication date: 2014-10-29
Also published as: DE102011121875A1; WO2013091754A1

Abstract

The invention relates to a wall element (100) that is arranged for thermal insulation of a vacuum system (1), comprising a planar heat-resistant insulating material and at least one reflective layer, which is arranged on at least one side of the insulating material, wherein the insulating material comprises a self-supporting foam body (10), the at least one reflective layer comprises at least one film (20, 21) fastened to at least one surface of the foam body (10), and engaging elements (30) designed for connection to a further wall element are provided on an edge surface (11) of the wall element (100). The invention also relates to an encapsulation that is configured for thermal insulation of a vacuum system and to a method for operating a vacuum system.

Description

Wall element and encapsulation for the thermal insulation of a vacuum system and method for their operation

The invention relates to a wall element, which is adapted for thermal insulation of a vacuum system, in particular a wall element, which is suitable for thermal insulation during the heating of the vacuum system and a sheet-like, heat-resistant insulating material and at least one reflection layer comprises. Furthermore, the invention relates to an encapsulation comprising a plurality of such wall elements. The invention also relates to a method for operating a vacuum system, in particular for thermal insulation of the vacuum system during baking, and the use of heat-resistant insulating material. Applications of the invention are given in the operation of vacuum systems, in particular in the shielding of vacuum systems, when in their operation, for. B. during heating, relative to the environment increased temperatures occur.

It is generally known to heat vacuum systems after their construction or after maintenance to accelerate the evacuation or to achieve an improved final vacuum. The annealing is carried out at a bake temperature, which is selected as a function of the temperature sensitivity of the vacuum system, typically in the range of 150 ° C to 300 ° C, over a period of several days. The baking temperature is set with a heater in the immediate vicinity of the vacuum system. In order to protect an environment of the vacuum system, for example in a laboratory, from undesirable overheating and to save energy, a shield is used. With the shield, the vacuum system is relatively thermally isolated to the environment. From practice, the following variants of shields are known.

According to a first variant, the conventional shield is formed by several layers of aluminum foil, with which the vacuum system and the heater are covered. The disadvantage is that the aluminum foil allows only a limited thermal insulation. Although heat radiation can be reflected back to the heating and the vacuum system, however, a discharge of heated air into the environment is prevented only to a limited extent.

According to a second variant, the conventional shield and the heater are provided together in the form of a jacket (also referred to as a jacket), the shape of which is adapted to the shape of the vacuum system or its parts. The jacket is a sewn from heating elements, mineral insulating materials and glass fiber fabric element, which is arranged in direct ^¬ tem contact with the vacuum system and often remains there during normal operation. The jacket shield has disadvantages due to the special shape adapted to the particular vacuum equipment used and due to the fact that the heating elements can cause uneven temperature distribution and thus thermally induced stresses in the vacuum system.

According to a third variant, the conventional shield has the shape of a tent. In this case, built around the vacuum system frame wearing an airtight tarpaulin, for example, fiberglass fabric. The heating is operated in the free space between the tarpaulin and the vacuum system. The heated air in the tent can be distributed with circulating fans, so that the vacuum system is evenly heated. The tent encapsulation, however, has only one limited insulation effect, so that a high energy consumption ^¬ arises. Furthermore, leaks in the tarpaulin can cause convection currents in the interior, which can cause undesirable thermal stresses when hitting the vacuum system, or allow heated air to escape into the environment.

Finally, a conventional shield according to a fourth variant in the form of a box, which is formed by solid panels (wall elements). The panels consist of two rigid metal plates between which a distance of, for example, 3 cm is filled with glass wool or a ceramic insulating material. The metal plates serve to hold the insulation material and to reflect heat radiation. To seal the box, the metal plates are joined together at their edges. For example, aluminum plates are riveted together or welded stainless steel plates together. In the interior of the box, the vacuum system and the heater are arranged, wherein the heated air can be distributed with circulating fans.

Although the box shield has an advantage through a good insulation effect. Of disadvantage, however, are the complex structure and the large mass of the box. The installation of the box is a lot of work and time. In

In the case of a change in the vacuum system, a complex reconstruction of the shield is required.

The above-mentioned problems occur not only in the annealing of vacuum equipment for cleaning purposes, but also in the other operation of vacuum equipment at elevated temperatures.

In the prior art heat-resistant foam is further known, for example, for thermal insulation of Sharing high temperature is used in engine technology. In this case, a foam jacket is used with a shape adapted to the part to be insulated, which rests on the part.

Finally, further applications of foam for insulation purposes are known from the prior art. For example, EP 344 850 B1 discloses a thermal insulation for a water reservoir, which is composed of foam insulating bodies each with an outwardly facing cover layer. However, this insulation has a limited mechanical stability. The foam is not independently stable, but protected by plywood reinforcing members against deformation. Furthermore, the insulation requires support through the water reservoir. DE 20 2010 014 348 U1 discloses a thermal insulation system with vacuum insulation panels which, however, are disadvantageous because of their complex construction. From DE 33 45 964 AI an insulating element for insulation against heat and sound is known, which is composed of a frame and a Dämmmaterial filling. Of the

Frame gives the insulating element the required mechanical stability, but has the disadvantage that it can be adapted to different application conditions only by a conversion of the frame. A thermally insulated water reservoir is described in DE 25 53 288 AI. The water tank carries on its outside a thermally insulating layer. Finally, DE 21 24 597 describes a thermal radiation protection for components in which a plate, e.g. made of hardboard, wood or plasterboard, covered with a reflective foil.

The object of the invention is to provide an improved shield for a thermal insulation of a vacuum system, wherein with the shield disadvantages of conventional Techniques are avoided. The shield should in particular provide a closed interior for receiving the component to be insulated, have a good insulation effect and / or be modifiable with little effort for adaptation to different vacuum systems. The object of the invention is also to provide an improved method for operating a vacuum system, which avoids the disadvantages of conventional techniques.

These objects are achieved by a wall element, a Verkaps- ment and a method for operating a vacuum system with the features of the independent claims. Advantageous embodiments and applications of the invention will become apparent from the dependent claims.

According to a first aspect of the invention, said object is achieved by a wall element (also referred to as a shielding wall element) which is suitable for thermal insulation of a vacuum system relative to its surroundings

is arranged and a sheet-like, heat-resistant insulating material and at least one reflection layer comprises, which is arranged on at least one surface of the insulating material. According to the invention, the sheet-like insulating material comprises a heat-resistant (heat-resistant) foam body. On at least one surface of the foam body, a film is attached, which forms the reflection layer. Notwithstanding conventionally used ceramic insulation materials, the foam body comprises a foam (in particular made of plastic). Advantageously, a simplified handling and a considerable mass reduction are thus achieved without the isolation capability being restricted. The wall element according to the invention is formed so that the thermal insulation (shielding) of the vacuum system a blockade both convection and thermal radiation into the environment.

The inventor has found that unlike conventional applications of heat-resistant foam shells, a cantilevered foam body can be formed which is suitable for producing a permanently stable wall element for thermal insulation of a vacuum system, in particular during its heating.

Unlike the conventional shielding of a vacuum system, the foam body does not require support by rigid plates. The wall element is preferably free of supporting support structures, in particular racks, bars, plates or scaffolding. The invention makes it possible that the at least one reflection layer is not formed by a plate, but by the likewise heat-resistant film, which is supported by the foam body and whose thickness compared to the thickness of the foam body can be negligible negligible. The use of the film allows further mass reduction compared to the conventional technique. The reduced mass of the wall element not only has advantages in the production and transportation of the wall element, but also in its application. Thus, when installing wall elements damage to the vacuum system for

Example be avoided by unintentionally tilting parts.

The wall element according to the invention is an areal component whose shape and size is determined by the shape of the foam body and which has two flat or curved side surfaces and a peripheral edge surface (peripheral edge). The wall element may have a planar or curved shape or be composed of both forms. The curved shape is, for example, a hollow shape of a sphere, a cylinder, an ellipsoid, or parts of these shapes. Typically, the conversion element has a constant thickness (extent perpendicular to the side surfaces) along its entire surface. Depending on the specific conditions of an application, however, the wall element can also be a varying thickness along the surface aufwei ^¬ sen.

One of the side surfaces (also referred to as the inner side surface) of the wall element has in its application to the vacuum system. The inner side surface carries the at least one film. An opposite side surface (also referred to as the outer side surface) of the wall element points away from the vacuum system during its application. The outer side surface may optionally also include a film and / or clamping elements for bracing adjacent wall elements and / or other operating parts, such. B. handles, wear.

According to the invention it is provided that on the edge surface of the wall element engagement elements are formed, which are adapted for connection of the wall element with another wall element. Preferably, the engagement elements are formed in the edge of the wall element. Adjacent wall elements, which are arranged adjacent to each other with their edges, can thus be mutually anchored by direct connection of the foam body. Additional components, such as retaining rails or scaffolding, are not mandatory.

The wall element according to the invention can be used individually to thermally isolate the vacuum system relative to the environment. For example, the wall element may have such a shape that the vacuum system of the wall element completely or partially enclosed. Alternatively, the wall element for thermal insulation individually, z. B. as a reflector of heat radiation in a particular spatial direction, or be used in combination with other shielding components. Preferably, however, several wall elements for thermal insulation of the vacuum system are combined.

According to a second aspect of the invention, said object is achieved by an encapsulation (also referred to as a shield encapsulation or heating box) comprising a plurality (at least two) of shielding wall elements. According to the invention, the wall elements each comprise a sheet-like foam body, which is heat-resistant at a baking temperature of the vacuum system, and at least one film which is fixed on at least one surface of the foam body. The wall elements are connected to one another, in particular at their edge surfaces, and they include an interior for accommodating the vacuum system.

Advantageously, the encapsulation forms a self-supporting construction. The wall elements of the encapsulation are arranged cantilevered. The foam body is at the same time insulating material and supporting structure. In contrast to the conventional box shield with two supporting metal plates, the distance is filled with insulating material, the at least one reflective film on the supporting foam body (foam core) is attached. The encapsulation is preferably free of additional support structures that are not formed by the foam body.

Particularly preferably, the encapsulation wall elements according to the above-mentioned first aspect of the invention. The Verkap In this case, the equation is composed of the wall elements which are connected to one another via the engagement elements.

The wall elements and encapsulation according to the invention have the following further advantages. It achieves excellent thermal insulation and thus dramatic energy savings when heating a vacuum system. The shield can easily and quickly be adapted to the current conditions of use. For example, if necessary, additional openings can be cut out with simple tools, such as a knife, or can close excess openings with adapted foam moldings. The wall elements are easy to repair. For example, broken parts can easily be glued on again. The low mass of the wall elements enables shortened assembly and disassembly times of the encapsulation. Finally, the wall elements and the encapsulant composed of these are significantly less expensive than conventional metal plate box shields and much more reliable than conventional tent shields.

According to a third aspect of the invention, the above object is achieved by a method for operating a vacuum system, in which an evacuation and a heating of the vacuum system is provided. According to the invention, the vacuum system is thermally insulated relative to the environment during annealing with at least one wall element according to the above-mentioned first aspect of the invention and / or an encapsulation according to the above-mentioned second aspect of the invention.

According to a fourth aspect of the invention, the use of heat-resistant (heat-resistant) foam Cloth body proposed for thermal insulation of a vacuum system. Preferably, the foam body is made of plastic. On at least one surface of the foam body, a film is attached, which acts as a reflection layer.

Preferably, the foam body of the wall element according to the invention is dimensionally stable. The foam of the foam body has such a dimensional stability that it does not deform under the action of its own mass and the at least one reflection layer, in particular at a baking temperature of the vacuum system. Furthermore, the foam of the foam body preferably has an intrinsic elasticity. The foam is elastically deformable. Thus, the connection of wall elements via the engagement elements, in particular in the formation of a dovetail toothing is simplified. Preferably, the foam body is an open-cell foam. This results in advantages for the dimensional stability, especially at elevated temperatures and for the formation of a frictional connection to touching parts of interconnected wall elements. However, it can also be used a closed-cell foam. The foam body of the wall element according to the invention is heat-resistant at a baking temperature of the vacuum system. Preferably, the foam is chosen so that the heat resistance at a temperature of 300 ° C, in particular 250 ° C is given. The heat resistance means that the foam body remains unchanged at the bake temperature in terms of its suitability for thermal shielding and the formation of the encapsulation, in particular the geometric shape and mechanical strength retains. Particularly advantageous melamine resin foam has proven, the For example, under the name Basotect-G (protected name) is commercially available. Polyurethane (PIR) rigid foam has also proven to be advantageous, for example as a high-temperature rigid foam from the manufacturer puren GmbH

(Germany) is commercially available.

Preferably, the foam body has a thickness of at least 50 mm, in particular at least 70 mm. This minimum thickness has proven to be advantageous for providing dimensional stability and isolation capability. Furthermore, the foam body preferably has a thickness of at most 200 mm, in particular at most 120 mm. A thickness less than or equal to this maximum thickness is advantageous for the handling of the wall elements.

The at least one reflective layer of the wall element according to the invention is preferably a metal foil, such as an aluminum foil. The metal foil preferably has a thickness of less than 0.5 mm, in particular less than 100 μιη, such as 50 μπι or less. The metal foil advantageously fulfills several functions.

First, heat radiation is reflected with the metal foil. With the metal foil, the insulating effect of the wall element is increased. Furthermore, the surface of the foam body, on which the metal foil is arranged, is pressure-stable. This simplifies the handling of the wall element, for example by manual gripping. Invasion of the fingers when gripping the wall element is avoided. Furthermore, the tensile stability of the foam body is increased at the surface, which is particularly advantageous for the stability of the foam body at its edges.

For the application of the wall element, it is sufficient if the foam body only on one of its (main) Surface carries the film. Typically, the side surface of the wall element, which carries the film, to the Vaku ^¬ umanlage (inner side surface). According to a partially adhere particularly before ^¬ embodiment of the invention, however, two of foils are provided, opposite to the

Surfaces of the foam body are arranged. The beid ^¬ side providing the films on the foam body increases the insulating effect and the pressure stability of the wall element.

According to a further advantageous embodiment of the invention, the at least one film is adhered to the surface of the foam body. For bonding, a heat-resistant adhesive, such as a heat-resistant silicone adhesive, is preferably used. Preferably, a point, strip or sheet-like adhesive connection between the film and the surface of the foam body is provided. Sticking on the film offers advantages in the construction of the encapsulation and in its modification or repair.

Particularly preferably, the engagement elements of the wall elements according to the invention are formed in at least one edge surface in the foam material of the foam body. The engagement elements, which in particular form a press fit, are formed in this case by the foam of the foam body. Advantageously, the foam has a rough surface on the edge surface which facilitates the formation of a frictional engagement between engagement elements of adjacent wall elements.

The engagement elements are shaped such that engagement elements on mutually connected wall elements are complementary to one another (complementary to a closed surface). can be set. The edges of the wall elements are preferably connected to each other without gaps. In other words, the engagement elements are preferably arranged to form a convection barrier between the wall elements when the wall element is connected to another wall element. Advantageously, the engagement elements allow a connection of the wall elements such that air flows between the wall elements are blocked. Air currents at a higher temperature than in the environment can not escape from the encapsulation, and air flows from the environment can not flow into the interior of the encapsulation.

Preferably, the engagement elements are shaped such that, in addition to holding forces for connecting the wall elements, they also absorb forces acting along the at least one edge of the wall element. Advantageously, the stability of the encapsulation according to the invention is thereby increased.

As an engagement element, all combinations of projections and recesses, such as pin-hole or pin groove or web-groove combinations are possible. Engagement elements which comprise pins and grooves which are formed on at least one edge of the foam body have proved to be particularly advantageous. The pins and grooves allow a toothing with another wall element. Further, when the pins and grooves are formed by straight cuts formed in the foam body perpendicular to the side and edge surfaces, they have an advantage of facilitating the manufacture of the engaging elements.

Alternatively or additionally, pins and grooves may be formed by cuts in the foam body which are inclined relative to the side and / or edge surfaces. At this Embodiment of the invention, the engagement elements are configured for the formation of a dovetail toothing. The dovetail toothing offers advantages for the stability of the connection of adjacent wall elements. If the cuts are inclined relative to the side surfaces and perpendicular ^¬ quite extend to the edge surface (the edge surface or relatively inclined and perpendicular to the side surfaces run), results in a simple dovetail toothing. This can for the coupling of wall elements in a plane, z. B. to form a flat side wall of an encapsulation, be beneficial. If the cuts are inclined relative to the side and edge surfaces, there is a double Schwal ^¬ benschwanzverzahnung. This can especially for the coupling of transverse wall elements, z. For example, to form a corner region of an encapsulation, be advantageous.

Preferably, the ratio of the width of the pins and the grooves along the edge direction of the foam body on the one hand and the thickness of the foam body on the other hand in the range of 1.5 to 2.5, in particular substantially equal to 2 is selected. This geometric dimensioning has proven to be advantageous for a high stability of the engagement elements. According to a further advantageous embodiment of the invention may be arranged on the outer side surface of the wall element clamping elements which are adapted for a tension of the wall element with another wall element. The clamping elements are formed so that the wall elements are pulled together at the edges where they are connected and subjected to a mechanical stress. They advantageously enable a stabilization of the encapsulation according to the invention. Although the engagement elements of the wall elements already for a self- ensure a close connection, the clamping elements provide additional reinforcement. The reinforcement serves, in particular, for stabilization when an increased internal pressure in the encapsulation, which can occur due to the temperature increase during the heating, or for stabilization against temperature-induced movements of the wall elements, is used. Columns can be avoided so that no hot air escapes and convection currents form. Preferably, the tension members comprise hook and loop fasteners and / or adhesive strips which extend from a surface of a wall panel to the surface of an adjacent wall panel over their interconnected edges. Velcro straps and / or adhesive strips have proven to be sufficiently stable and particularly easy to use.

Preferably, the wall element according to the invention has a closed surface. The closed surface offers advantages for the insulation effect and the mechanical stability. Alternatively, depending on the specific application of the wall element, this may have at least one recess, in particular a depression formed in the thickness direction and / or an opening extending in the thickness direction. According to a first variant, the depression may be configured for insertion of a ventilation device (circulation fan). In this case, a circular or rectangular recess is provided, in which the round or square frame of the ventilation device, for example, a circulating fan can be used. According to a second variant, an opening for carrying out a conduit device can be configured. The line device comprises, for example, electrical supply lines for supplying at least one heating device inside the encapsulation and / or electrical sensor connections of temperature or temperature Pressure sensors. According to a further variant, an opening for coupling an insulation sleeve can be configured. For example, the vacuum system may have a pipe connection with a vacuum pump, wherein the pipe connection is not completely baked. In this case, the pipe connection is guided through the opening in the wall element to the outside. For thermal insulation of the pipe connection in the immediate vicinity of the encapsulation, the insulation sleeve, for example in the form of a hollow cylinder, can be provided, which is connected to the opening in the wall element.

According to a particularly preferred embodiment of the invention, the encapsulation has a box shape with straight walls. The walls comprise at least one bottom plate, side walls and at least one cover plate, which are formed by a plurality of wall elements according to the invention. The box shape has advantages for a simple construction of the encapsulation of wall elements and for the creation of an interior around the vacuum system, which assists an all-round air circulation during heating.

Preferably, in the interior of the encapsulation at least one particular electrically actuated heater is arranged, with which the vacuum system is bakeable. The heater may include a plurality of heating elements. It can z. B. a plurality of heating elements may be arranged to be movable, which are arranged hanging on the bottom plate or on the side walls and / or the cover plate.

According to further preferred variants of the invention, the encapsulation is equipped with at least one ventilation device, at least one conduit device and / or at least one insulation sleeve, in order to perform the functions of circulation in the interior, the electrical circuit Supply to meet the at least one heater and / or the sensors and the outer shield of pipe joints.

Further details and advantages of the invention will be described below with reference to the accompanying drawings. Show it:

FIG. 1 shows a schematic perspective view of a preferred embodiment of the wall element according to the invention,

FIG. 2: schematic illustrations of details of preferred features of the shielding element according to the invention,

FIG. 3: schematic illustrations of further details of preferred features of the shielding element according to the invention,

FIG. 4 shows a schematic perspective view of an encapsulation according to the invention; and

Figure 5: a schematic perspective view of the interior of an encapsulation according to the invention.

Embodiments of the invention are described below by way of example with reference to a planar wall element with a pin-groove toothing and an encapsulation, which is composed of a plurality of planar wall elements. It is emphasized that the implementation of the invention is not limited to the form of the wall element and the engagement elements shown as an example, but can be realized in accordance with other shapes and engagement elements. The invention is further described by way of example with reference to the application in the annealing of a vacuum system, such as an MBE device. It is emphasized that the application of the invention is not limited to the annealing of vacuum equipment for coating purposes. Alternatively, the invention may be used, for example, in the annealing of other vacuum equipment or combined vacuum and cryogenic equipment. Details of vacuum systems are not described here, since these are known per se from the prior art.

1 shows a preferred embodiment of a wall element 100 according to the invention comprising a core of a foam body 10 and foils 20, 21 arranged on both sides. The wall element 100 has the shape of a flat plate with a peripheral edge surface 11 on which engagement elements 30 are provided. The wall element 100 extends in the plane of the drawing (x-y plane). In use, for example, the forward facing side surface forms the inner side surface of the wall member 100 in an encapsulation while the rearwardly facing side surface forms the outer side surface of the wall member 100.

The foam body 10 comprises plastic with a constant temperature resistance at least 200 ° C. Since elevated temperatures also occur when heating a vacuum system, for example at 200 ° C., the selection of a foam with a short-term temperature stability at 250 ° C. is advantageous. The selection of a suitable foam is carried out by a person skilled in the art by the evaluation of the data supplied by a foam manufacturer. The foam body 10 is made, for example, from the commercially available open-celled melamine resin foam Basotect-G (protected name). Another example is rigid polyurethane (PIR) foam. The films 20, 21 are made of aluminum. They are laminated to the surfaces of the foam body 10. The lamination serves both the thermal insulation and the mechanical stabilization of the foam body 10. The use of aluminum foil with a thickness of about 30 μm makes the surface of the foam body 10 so pressure-stable that, when handled manually, the fingers do not penetrate the foam Break in foam.

The lamination is carried out using a permanently elastic, thermally stable adhesive, in particular temperature-stable silicone adhesive, for example commercially available adhesive with the name "Ottoseal 25" (protected name)

280 ° C and short-term temperature stable up to 315 ° C. For fixing the aluminum foils 20, 21, the adhesive is applied in strip form to the surfaces of the foam body 10 with a compressed air applicator. For example, strips with a diameter of 3 mm to 5 mm and a spacing of 30 mm are provided. The aluminum foils 20, 21 are placed on the surfaces provided with the adhesive and pressed. The fixation of the aluminum foils 20, 21 may be provided prior to the formation of the engagement elements 30. Alternatively, the lamination can be provided on the already preformed core of the foam body 10 with the finished engagement elements 30. In this case, modification of the aluminum foils 20, 21 on the engaging elements is facilitated, as will be explained in more detail below with reference to Figs. 2A to 2C. The engagement elements 30 comprise a series of pins 31 and grooves 32 formed in the edges of the foam body 10. The pins 31 and grooves 32 are complementary to the grooves 32 and pin 31 formed on an adjacent wall element (see Figure 4).

For the connection along vertical (in the y-direction) extending edges of the encapsulation 200 of the invention (see Figure 4), the pins 31 and grooves 32 preferably have the same width B in the edge direction. Furthermore, the depth T of the pins 31 and grooves 32 is preferably selected to be equal to the thickness D of the foam body 10 in the thickness direction (z-direction). For the creation of a reliable connection of the wall elements, it has proven to be advantageous if the width B of the pin 31 and grooves 32 is twice as large as the thickness D of the foam body 10th

For the connection along horizontally (in the x-direction) extending edges of the encapsulation 200 according to the invention a deviating geometry can be provided. It is preferred to provide fewer engagement elements at the edges provided in the encapsulation 200 for connection to the bottom and top plates. There are fewer engagement elements than at the vertical edges is sufficient, since the connection to the floor and cover plates is stabilized by their own weight.

For a universal usability of wall elements 100, it is advantageous if the engagement elements 30 are formed complementary to one another at two mutually opposite edges of the wall element 100. This is illustrated in Figure 1 at the left and right edges (in the y direction). The complementary formation allows a seamless toothing of the wall elements along the side walls of the inventive method. Encapsulation 200 (see Figure 4). The engagement elements on the remaining edges could also be formed complementary to one another and / or to the engagement elements in further wall elements, which form the bottom and cover plates of the encapsulation.

The dimensioning of the wall element 100 according to FIG. 1 takes place as a function of the specific conditions of use. The thickness D is chosen in particular depending on the desired cantilevered widths of the side walls and ceiling and floor slabs in the finished encapsulation. If the encapsulation has a height of, for example, 50 cm, a thickness D of 50 mm has proven sufficient. With a height of encapsulation of up to 2 m, however, a thickness D of 100 mm is an advantage.

FIGS. 2A to 2C illustrate different variants of the lamination of the foam body 10 in the region of the pins 31. If the lamination is provided before the shaping of the engagement elements 30, the aluminum foil 20 extends from the surface of the foam body 10 except for the pins 31 (FIG. 2A). If the lamination takes place only after the formation of the engagement elements 30, the aluminum foil 20 is cut to size. For example, the aluminum foil 20 may cover the trunnions 31 along the surface of the foam body 10 and beyond according to an envelope in the thickness direction of the foam body 10. The envelope may cover the edge surface 11 partially (Figure 2B) or completely. This variant may have advantages for a more reliable fixation of the aluminum foil 20 on the foam body 10. Alternatively, it can be provided according to FIG. 2C that the pins 31 do not carry aluminum foil. Advantageously, in this case, the formation of thermal bridges at corners of the encapsulation 200 avoided.

FIGS. 2A to 2C illustrate that the pins 31 can have a taper at their free ends. In this case, the mounting of the encapsulation 200 from the wall elements is simplified. Pins with the tapers shown, however, can only be provided at connections between wall elements in corner areas. Otherwise, gaps are created which could undesirably cause air to escape from the interior of the encapsulation during heating.

FIG. 2D illustrates that the edge surface 11 of the foam body 10 can be provided with a labyrinth seal 33. The labyrinth seal 33 comprises z. B. two webs which extend in the edge direction and engage in two grooves (not shown) of a complementarily formed edge surface 11 of an adjacent wall element. FIG. 2E schematically shows a tensioning element in the form of a hook-and-loop fastener 41, which is provided between two wall elements 100, 101 connected to one another. With the hook-and-loop fastener 41, the assembled wall elements 100, 101 can be mechanically clamped together in order to close any gaps between the wall elements 100, 101. The Velcro fastener 41 is composed of Hakenband- and loop tape sections.

Preferably, the hook-and-loop fastener 41 is designed such that two sections of hook tape are glued piecewise over the entire surface on the outer side surface of the respective wall element, for example on the aluminum foil. The connection with the volume of the foam body 10 can be further improved by the hook tape sections of the hook and loop fastener 41 are anchored with a dowel extending into the depth of the foam silicone rubber. Upon curing of the adhesive is an elastic dowel which the Alumi ^¬ nium foil and the stuck thereon hook tape is stably transfected with the volume of the foam body 10 connects. In the fer ^¬ term encapsulation, the matching one another attached hook tape-sections are a loop strap section verbun ^¬. As an alternative to the hook-and-loop fasteners 41, clamping of the wall elements 100, 101 with adhesive strips 42 may be provided, which has particular advantages in dismantling the encapsulation.

FIG. 3A illustrates that the pins 31 and grooves 32 can be formed by oblique, plane cuts in the foam body 10. The cuts are inclined both relative to the side surfaces of the foam body 10 and relative to the edge surface 11 so that the pins 31 and grooves 32 are configured for double dovetail toothing. The

Dovetail toothing 34 between mutually transverse wall elements 100, 101 is shown by way of example in FIG. 3B. Advantageously, the dovetail teeth can be easily assembled by locally deforming the foam of the pins 31 and grooves 32 and locking the pins 31 and grooves 32 into each other.

FIG. 4 shows a preferred embodiment of the encapsulation 200 according to the invention with a multiplicity of wall elements 100, 101 in the assembled state. FIG. 5 schematically shows the interior 207 of the encapsulation 200, in which the vacuum system 1, a plurality of heating elements 208, 209 and a ventilation device 50 (circulating fan) are arranged. The vacuum system 1 is simplified and shown schematically. In practice, the vacuum system 1 z. B. an MBE device with multiple vacuum chambers. The encapsulation 200 comprises a bottom plate 201, side walls 202 to 205 and a cover plate 206. The sides of the encapsulation 200 are each made up of a single wall element, such as a single wall element. B. at the bottom plate 201 and / or the cover plate 206, or formed from a plurality of wall elements 100, 101, such. B. at the front side wall 203, composed. The wall elements are connected to one another at their edges via the engagement elements 30. In the corner regions, the wall elements are clamped together using the clamping elements (Velcro fasteners 41 and / or adhesive strips 42, see FIG. 2E). The clamping elements are optionally provided and can be dispensed with, in particular when forming a dovetail toothing (see FIG. 3).

The wall element that forms the bottom plate 201 rests on a support frame 2 and / or support columns 3. In the bottom plate, the ventilation device 50 is inserted (see Figure 5). The support columns 3 can be made of the same foam as the wall elements according to the invention. Notwithstanding the illustration, the bottom plate 201, the side walls 202 to 205 and / or the cover plate 206 may be formed with further recesses and / or steps. The wall member forming the side wall 204 includes an opening to which an insulation sleeve 12 is connected. Through the insulation sleeve 12, a pipe connection 4 (see FIG. 5) is led to the outside, via which a vacuum pump is connected to the vacuum system 1 in the interior of the encapsulation 200. Furthermore, the wall element 102 contains openings for a conduit device 51 which, for example, comprises electrical supply lines for the heating elements 208, 209 of the heating device in the interior of the encapsulation 200. Furthermore, in the wall element, for example, the cover plate 206 forms, a further opening for a sensor line 52 may be provided, which is connected to a temperature sensor in the interior (not shown). Notwithstanding the illustration in Figure 4, the encapsulation 200 may be formed with wall elements made of temperature-resistant foam, on the edge surface of which no engagement elements are provided. In this case, the wall elements preferably have a sectionally planar, perpendicular or inclined relative to the side surfaces extending edge surface. In this embodiment, the above-mentioned clamping elements are preferably provided for bracing the wall elements.

For operation according to the invention of the vacuum installation 1, the encapsulation 200 according to the invention around the vacuum installation 1 is constructed as follows.

First, the bottom plate 201 of one or more foam body part (s) on the support frame 2 of the vacuum Anläge 1 is mounted. The bottom plate 201 or parts thereof are placed on the support frame 2 or pushed between system parts. Slots between foam body parts and the flexibility of the foam allow the panels of foam body parts to be inserted between vertical support bolts of the vacuum system 1. The heating elements 211, 212 are not fixedly mounted to the encapsulation 200 bake box, but can be mounted as movable units at appropriate positions the bottom plate 201 are arranged. Should it turn out that more or less heating power is needed than intended, heating elements are simply removed or additional heating elements placed in the encapsulation 200. By pins on the edges of the bottom plate 201, the side walls 202 to 205 engage at the fixed positions on the bottom plate 201. Not particularly many pins must be provided here because the side walls 202 to 205 are already pressed by their weight and the subsequently applied cover plate 206 on the bottom plate 201 and therefore the friction on the contact surfaces of the pins and grooves is not necessary for the sealing effect. The side walls 202 to 205 are also connected to each other by grooves and pins. Here, the tapping is preferably narrower, and the pitch of the tenons is optimally twice the plate thickness D as stated above. If the cantilevered cover plate 206 is too large to be manufactured integrally, it is also composed of a plurality of foam body parts. The cover plate 206 is z. B. composed of two parts and at the interface by an over ^¬ glued path aluminum foil on the one hand hermetically sealed and on the other hand connected as a hinge. Beyond the support frame 4 protruding portions of the bottom plate 201 are supported. This can also be done very inexpensively by put together foam parts, which form the support columns 3.

Non-heatable, temperature-sensitive system components should remain as cool as possible during baking. Due to the good insulating effect of the foam, the thermal delimitation of these parts of the system by the invention is simple and effective: the foam, optionally inserted by additional foam pieces, seals these parts very well, and the escape of hot air is avoided. In contrast to conventional shields with metal panels, the circulating fan is advantageously integrated into the base plate 201 in the invention. By this arrangement, the side walls 202 to 205 and the cover plate 206 of the encapsulation 200 is not burdened by the weight of the circulating fan and a fan frame (not shown) may serve to support the bottom plate 201. The vacuum system 1 is evacuated and the heating elements 211, 212 are actuated in order to set a baking temperature of, for example, 200 ° C. in the interior of the closed encapsulation 200. Depending on the complexity of the vacuum system 1, the heating up can take several hours or up to several days. For the heating of the vacuum system 1 on z. B. 200 ° C z. B. 5 kW heating power provided, where approx. 3 kW in the upper region of the interior 207 and 2 kW for the area below the vacuum system 1, z. B. below the growth chamber of the MBE device generated. This corresponds to about half of the previously required for a comparable size plant performance. The outer side surface of the encapsulation 200 can still be touched by hand at an internal temperature of 200 ° C. Again, this is not possible with the conventional shields. The insulating effect is thus clearly better than in conventional techniques. With the improved energy balance, it should also be borne in mind that the heat-up procedure normally takes place in air-conditioned laboratory rooms, ie the surplus heat usually has to be additionally transported away in a costly manner via a room cooling system.

After annealing, the clamping elements 41, 42 are removed and the encapsulation 200 degraded in the reverse order, followed by the regular operation of the vacuum system. 1

The encapsulation 200 according to the invention is particularly suitable for vacuum systems that are often modified or rebuilt. In conversions, in conventional box shields, a complex machining of metal plates with a ner previous removal of the insulation material required. Likewise, the closure of no longer required openings is complicated, since at least holes for locking plates must be introduced into the corresponding metal plates. Larger conversions, such as an increase in volume or change in shape of the entire box are even more expensive. In contrast to conventional box shielding, the encapsulation according to the invention offers the advantage that it can be easily adapted by the user. For this purpose, only simple tools, such as a knife, metal foil and an adhesive cartridge and possibly additional foam pieces are required. If necessary, new openings can be easily cut with the knife from the existing wall elements. For no longer required openings a matching closure part made of foam is cut, glued into the opening and pasted over both sides with metal foil. Trims, bulges or indentations and intermediate pieces can also be cut on site, if necessary with the aid of existing parts as connection templates and glued or glued with metal foil.

The features of the invention disclosed in the foregoing description, drawings and claims may be significant to the realization of the invention in its various forms both individually and in combination.

Claims

A wall element (100, 101) adapted for thermal insulation of a vacuum system (1), comprising:

a sheet-like, heat-resistant insulating material, and

at least one reflection layer, which is arranged on at least one side of the insulation material,

characterized in that

the insulation material comprises a cantilevered foam body (10),

- The at least one reflection layer comprises at least one film (20, 21), which on at least one surface of the

Foam body (10) is attached, and

- On an edge surface (11) of the wall element (100) engaging elements (30) are provided which are adapted for connection to a further wall element (101).

2. Wall element according to claim 1, wherein the foam body (10) has at least one of the features:

- The foam body (10) is dimensionally stable,

- The foam body (10) comprises an open-pore

foam,

the foam body (10) comprises an elastically deformable foam,

the foam body (10) comprises a flat plate,

the foam body (10) comprises a curved plate, the foam body (10) is at a temperature of

300 ° C, especially 250 ° C heat resistant,

the foam body (10) has a thickness of at least 50 mm, in particular at least 70 mm, - The foam body (10) has a thickness of at most 200 mm, in particular at most 120 mm, and

the foam body (10) comprises a melamine resin foam or a polyurethane foam.

3. Wall element according to one of the preceding claims, wherein at least one of the features is provided:

the at least one foil (20, 21) comprises a flexible metal foil,

the at least one film (20, 21) is fastened on a surface of the foam body (10) facing the vacuum system (1),

- The at least one film (20, 21) is glued to the surface of the foam body (10), and

- Two films (20, 21) are provided, which are fixed on the opposite surfaces of the foam body (10).

4. Wall element according to one of the preceding claims, in which the engagement elements (30) have at least one of the features:

the engagement elements (30) are formed in the at least one edge surface (11) in the foam material of the foam body (10),

- The engagement elements (30) are formed on at least two opposite edge surfaces (11) of the foam body (10) complementary to each other,

- The engagement elements (30) comprise pins (31) and grooves (32),

- The engagement elements (30) are for the formation of a

Dovetail toothing (34) configured, and

the engagement elements (30) are configured to receive forces acting along the at least one edge of the wall element (100).

5. Wall element according to claim 4, wherein

- The engagement elements (30), the pins (31) and grooves (32) and a ratio of the width (B) of the pins (31) and grooves (32) and the thickness (D) of the foam in Be ^¬ rich of 1 , 5 to 2.5, in particular equal to 2, is selected.

6. Wall element according to one of the preceding claims, wherein

- The engagement elements (30) are arranged, when connecting the wall element (100) with another wall element (101) to form a convection barrier between the wall elements (100, 101).

7. Wall element according to one of the preceding claims, wherein

- Clamping elements (40) are provided, which are arranged for a bracing of the wall element (100) with another wall element (101).

8. Wall element according to claim 7, wherein

- The clamping elements (40) are connected to one of the vacuum system (1) pioneering outer side surface of the wall element (100, 101),

- The clamping elements (40) Velcro fasteners (41) and / or Kle ^¬ stripe (42) include.

9. Wall element according to one of the preceding claims, the

- Has at least one recess which is adapted for insertion ei ^¬ ner ventilation device (50), for carrying out a conduit means (51, 52) and / or for coupling an insulation sleeve (12).

An encapsulant (200) configured for thermal isolation of a vacuum system (1), comprising:

- A plurality of wall elements (100, 101), each comprising a planar, cantilevered and heat-resistant foam body (10), and at least one foil (20, 21) attached to at least one surface of the foam body (10) is, where

- The wall elements (100, 101) are interconnected and an interior space (207) for receiving the vacuum system (1) include.

11. Encapsulation according to claim 10, wherein at least one of the features is provided:

the wall elements (100, 101) are connected together at their edges,

- The wall elements (100, 101) form a bottom plate (201), side walls (202 - 205) and a cover plate (206), and

- The wall elements (100, 101) are arranged cantilevered.

12. Encapsulation according to one of claims 10 or 11, wherein at least one of the features is provided:

at least one of the wall elements (100, 101) carries a ventilation device (50),

- At least one of the wall elements (100, 101) has a passage of a conduit means (51, 52), and

- At least one of the wall elements (100, 101) is connected to an insulation sleeve (12).

13. Encapsulation according to one of claims 10 to 12, in which

- In the interior (207) at least one heating device (210) is arranged.

14. Encapsulation according to one of claims 10 to 12, which is composed of wall elements (100, 101) according to one of claims 1 to 9.

15. Method for operating a vacuum system (1), comprising the steps:

- Evacuate the vacuum system (1), and

- Heating the vacuum system (1), wherein the vacuum system (1) with respect to its surroundings with at least one wall element (100, 101) according to one of claims 1 to 9 and / or an encapsulation (200) according to one of claims 10 to 14 is thermally isolated.

16. Use of heat-resistant foam having on at least one surface of a film (20, 21), forming a wall element (100, 101) for a thermal insulation of a vacuum system (1).