HUP0003237A2 - Pipe shell insulating pipe, arrangments for insulating pipes and method for manufacturing pipe shell - Google Patents

Description

PUBLICATION COPY ||

Pipe insulation shell, pipe insulation systems and method for manufacturing pipe shells 4

The invention relates to pre-formed pipe insulation shells that can be easily and quickly placed around the pipes to be insulated, including very cheap and light, flexible and elastic, thin, multi-layered pipe shells, their use and production.

Various solutions have long been used in various sectors of industry and building engineering to thermally insulate pipes and their fittings that transport media (liquids and/or gases) that are warmer or colder than their surroundings.

In general, it can be said that there are two types of insulation solutions, one of which is that the insulation must be slid onto the pipe, usually simultaneously with the longitudinal construction of the pipe, in its length, and the other solution is that any section of the already completed, long pipeline can be subsequently surrounded by the insulation. In building engineering, the latter solution is much more advantageous, therefore we deal with such solutions in the present invention. Within this, many different approaches are known.

According to one type of known solution, the pipe to be insulated is surrounded by metal plates arranged in a cylindrical shape, in one or more layers, and no other solid insulating material is used. In these systems, the enclosed air layer insulates against conduction and convection, and the metal plate, due to its radiation-reflecting properties, protects against radiation heat exchange. Such a solution is contained, for example, in US 2,078,606. Patent description. These systems provide good insulation, but at the same time, since their structural elements are made of metal plates, and the fastening of these plates requires complicated support systems, they are quite expensive, heavy and complicated, difficult to implement. Due to these disadvantages, the use of such solutions has not really spread, but rather non-metallic strength-giving elements are used, which are lighter and cheaper, and if necessary,

radiation reflection with a thin metal layer (e.g. metal foil or metal vapor layer). The present invention also deals with the latter type of solutions.

In some solutions, the space around the pipe to be insulated is filled with an insulating material in the form of a cylinder that is essentially coaxial with it. Such solid insulating materials include, for example, fibrous wools made of mineral materials, glass or plastic, extruded or expanded polystyrene, and various other, typically closed-cell plastic (e.g. polyurethane or polyolefin) foams. According to one solution, the pipe to be insulated is wound around with strips of insulating material, threadedly or wrapped with longitudinal strip(s), and immediately afterwards, as a separate operation, the applied insulating material is permanently fixed to the pipe. Typically, fibrous insulating material, e.g. glass wool, is used as the insulating material, and the insulating material is wrapped around with a metal strip as the fixing, which prevents the insulating material from unwinding or slipping. Another fixing solution is contained in US 5,771,941. patent specification, according to which the mechanical protection of the insulating material is provided by snapping a cylindrical tube shell molded from hard PVC, slit along one of its edges, onto the pipe wrapped with the insulating material, which tube shell is thick and rigid enough to permanently hold the insulating material in place. Any solution in which the material used, usually in several strips, has to be fixed along the edge with a separate device or has to be wound onto the pipe turn by turn, is disadvantageous because it is excessively time-consuming and typically requires great attention and expertise.

According to a more convenient solution, prefabricated, thick-walled, elongated, cylindrical pipe shells are formed from the insulating material, with which the covering of a longer (e.g. 1-2 meter long) pipe section can be easily carried out by installing or snapping on a pipe shell having the shape of a pipe split along one of its components. The essence of this type of solution is therefore that it is not necessary to wind anything around the pipe in a threaded manner and it is not necessary to bother with immediately fixing any longitudinal strips separately, because the entire affected pipe section can be surrounded by the pipe shell at once, and from the moment of installation, the pipe shell holds on to the pipe and does not fall off. Since this type of solution can be used much more conveniently than the previously mentioned ones, the objectives of the present invention are also related to pipe shells.

Such pipe shells made of foamed plastic or mineral wool are widely used for pipe insulation in building services, because their application is simple, fast, and does not require expertise or special tools. Although their price is lower than that of the previously mentioned insulations made of metal sheets, it is still quite high, as they contain a significant amount of thermal insulation material and can be manufactured using complicated operations. Another disadvantage is that they are bulky, which is why they are expensive and can only be transported over short distances.

US 4,606,957. Patent description describes that the insulating material cylinder acting as a pipe shell can be factory-wrapped from the outside with a flexible wrapping layer, which is held by the insulating material cylinder after wrapping, and which may also have a metallized layer. The wrapping operation, e.g. according to US 4,909,282. Patent description, is carried out by winding the wrapping material onto the insulating material cylinder, from a direction perpendicular to its axis, in a suitable length, tangentially, e.g. while the insulating material cylinder is rotated about said axis. The outer wrapping sheet may include a free, overlapping strip overhanging the slot, which may have a self-adhesive surface covered with a silicone protective layer, which helps to finally seal the slot. One of the disadvantages of this solution is that when repairing the insulation, it is not possible, or only very difficult, to disassemble and separate the outer covering from the insulating material. Most of the common types of insulating material pipe shells mentioned above also have versions with such an outer protective covering, e.g. reinforced aluminum foil, which are factory-fitted, but unfortunately these are available at a rather high premium and (perhaps for this very reason) are less frequently sold in the trade than the versions without covering. The above-mentioned method of covering can only be carried out afterwards, e.g. at home, with great difficulty. US 5,400,602. Patent description describes a system in which two pipes running next to each other are thermally insulated by first wrapping the pipes together, perpendicular to the axis, with a radiation-reflecting foil, e.g. (with a wrinkled surface to reduce the contact area and thus the heat transfer) with aluminized polyester foil, and then this is surrounded in the usual way with a closed-cell polyolefin foam pipe shell. The disadvantage of this solution is that although the foam pipe shell can be quickly and easily installed on the pipe, the application of the lower foil covering is a relatively difficult operation, and in the event of a repair, the removal of the lower foil covering is also a problematic and slow operation.

Instead of the aforementioned outer and inner foil coverings, for the sake of convenient and quick installation, we could use the previously mentioned strong and rigid plastic molded pipe shell according to US 5,771,941., however, this would be too expensive, since (precisely in order to preserve the shape of the pipe shell) it does not consist of a thin foil, but of a relatively thick-walled pipe. A pipe with too thick a wall cannot be used for this purpose either, because it would take up too much space and thus make the entire insulation too thick. Instead of the aforementioned outer or inner additional foil covering, consisting of a foil to be wound from a direction perpendicular to the longitudinal axis of the pipe, we could also use US 3,616,123. no. a laminate with a threaded self-shaped structure according to the patent description, the advantage of which would be that by layering strips consisting of sufficiently thin foils on top of each other, by winding the multilayer strips in a thread and by solidifying the fastening between the layers, we could even obtain a sufficiently thin, self-shaped covering material, however, the disadvantage of this is that the said self-shaped structure would be a flexible sheath consisting of separate threads, similar to a spiral spring, which would have to be wound up thread by thread along the pipe to be insulated, which is an excessively difficult operation even if the laminate has a threaded self-shaped structure forming the appropriate diameter, since this structure can be placed on the pipe much more difficultly and more slowly than the pipe shell. Also, solutions for covering longer pipe sections with flexible, coiled tapes are found in US 4,304,268 and US 3,904,467, which also have the disadvantages of coiled tape. None of these solutions include a substantially elongated tube shell that can cover a longer pipe section at once, but either include only coiled tape or form a narrow tape or strap to wrap the pipe at a single location, without significant longitudinal extension.

US Patent No. 6,000,420 describes a molded pipe jacket pipe insulation system in which the insulating means is a hollow pipe shell molded from thermoplastic. In this solution, an air layer enclosed between the thin plastic jacket and the pipe to be insulated inside insulates against conductive and convective heat exchange, while against radiant heat exchange, if necessary, a thin radiation-reflecting layer attached to the molded plastic pipe shell can be used. The insulating jacket consists of cylindrical plastic pipe shell segments, slit along one of their members and hinged along the opposite member to allow opening, but otherwise rigid and strong, which simply have to be snapped onto the pipe to be insulated through the longitudinal slit. The shells are positioned around the pipe to be insulated by suitable spacers (e.g. plastic spokes or ribs). The cylindrical shell forming the shell can be manufactured from thermoplastic plastic (e.g. PVC) by injection molding, profile extrusion or (as the cheapest option) by vacuum forming (collectively called: casting). In order for the cast cylindrical shell to have sufficient mechanical shape retention, its wall thickness is relatively large, at least approx. 1.27 mm. The advantages of this solution are simple and quick installation and, since it does not contain any space-filling insulating material or expensive metal structure, it can be manufactured somewhat cheaper than the previously mentioned complete insulation solutions. The disadvantage of this solution is that the product is still more expensive than desired due to the material cost of the relatively thick plastic jacket and the complexity of the molding processes, and is also plagued by the previously mentioned high shipping costs due to the bulkiness. According to the cited description, in the molded pipe jacket system, the plastic pipe jacket is sufficiently rigid and strong (and correspondingly thick and expensive) to reliably maintain its own rigid shape and to withstand possible external influences without deformation, such as the loading of the pipe shell with a ladder or a foot. However, from the point of view of thermal insulation alone, a single thin film (e.g. MYLAR™ polyester film) would be equivalent to the cast jacket, as the cited description also indicates when it describes that during the laboratory test, an additional layer of air was experimentally formed by experimentally placing an additional layer of film, reinforced in a cylindrical shape, inside and outside the cast pipe jacket. However, the cited description does not set a goal or provide a solution as to how, outside the laboratory, a simple, thin film-like, but still self-supporting, cheaper jacket could be used instead of the cast pipe jacket in practice.

- good

Further prior art documents will be mentioned later, at the appropriate places.

The object of the invention is to provide a cheaper and/or easier to handle device for use in the thermal insulation of pipes and pipe fittings than currently known pipe thermal insulation solutions. More specifically, our object is to provide a thin-walled, multi-layer, flexible and elastic pipe shell, which pipe shell, due to its shape and sufficient shape retention in practice, provides easy installation and pipe shell-like usability, and at the same time is cheap due to its thinness, and can also be used as various external and/or internal covering films. Our object is to present a new, cheap, easy and quick to assemble and disassemble pipe insulation system using a thin, multi-layer pipe shell. Our object is also to describe a cheap and convenient to use insulation system containing a thin-walled, multi-layer pipe shell for use in the insulation of pipes and/or pipe fittings. Our object is also to present a method for manufacturing a thin, multi-layer pipe shell. In addition to the above objectives, we generally strive to present versions with additional advantages (e.g. with the greatest possible savings in solid insulation material).

A significant part of the building services pipe insulation is placed well above the floor level or in closed tunnels or above false ceilings, therefore they are very rarely exposed to any harmful external force after installation. Referring back to the solution according to the patent description US 6,000,420, we take advantage of the fact that the strength provided by the cast pipe jacket, mentioned there, is generally not needed, and that therefore, instead of the cast pipe jacket, a thin, flexible and elastic, multilayer (e.g. containing several foil layers), curved sheet can be successfully used, which is strong enough to (by itself or when installed around the pipe to be insulated, with the help of positioning devices) maintain its own, desired shape of the pipe shell, and thus the desired shape of the enclosed air space, and which reacts to any external force with elastic indentation or bending, i.e. after the force is removed, it elastically regains its intended shape. Such a pipe insulation provides the same insulation as a cast pipe jacket, but this new jacket, due to its thinness, can contain much less material (in one possible case, e.g. 20 times as much) and can therefore be produced much cheaper than a cast pipe jacket. Such a thin, multi-layer pipe jacket is also excellently suited for additional cladding inside or outside pipe insulation pipe jackets made of solid insulating material.

Our fundamental insight regarding the inventive tube shells is that our objectives can be achieved by using a thin (e.g. foil-like) multilayer tube shell in which the necessary flexibility and/or the necessary self-curvature are ensured by at least two separate layers being attached to each other (e.g. by lamination) instead of using a single separate layer of thin material (e.g. plastic film). A sheet containing two separate layers, especially if there is a third intermediate layer between them providing a certain distance, tends to regain its original shape much more strongly in the event of deformation (e.g. bending, denting) than a single layer of such material. The explanation for this is that when the sheet is bent, i.e. deformed from its original shape, the individual layers, due to the fact that their center lines are not in the same plane, undergo stretching or compression, which they resist, and this resistance to stretching or compression results in the elastic resistance of the entire sheet to bending deformation. Said stretching or compression is greater the thicker the wall of the tube shell, i.e. the greater the distance between said center lines. Materials manufactured in a flat shape, e.g. plastic films, can be very easily and cheaply manufactured with parameters such that, while they are completely flexible, i.e. their surface can be bent practically without resistance, they react to stretching (and similarly to compression) with a strong elastic resistance. They can even behave more or less inextensible, despite the fact that their thickness is very small, e.g. 12 microns, compared to the usual thickness of cast tube shells of over 1 mm. This can be achieved, for example, in the case of plastic films, by the usual method of orienting the plastic film very strongly in its own plane during its manufacture. Such an orientation cannot be achieved when casting pipe jackets, especially in the more important, circumferential direction. Other thin, flexible and difficult-to-stretch flat materials can also be produced cheaply and simply, e.g. paper, various, e.g. natural, plastic or glass fabrics, etc. If the lengths of the adjacent individual layers within the sheet left alone free from external deforming effects are not equal, then the original shape of the multilayer sheet is not flat, but curved, which effect applies even if the layers are very thin, and this makes it possible to manufacture pipe jackets with a desired own curvature with very small wall thicknesses. Several previously cited patent specifications deal with curling, multilayer products with such curvature, but their objectives and recognitions differ from those of the present invention.

As we have said, our objective is a thin-walled, multi-layer, flexible and elastic pipe shell, which pipe shell, due to its shape and sufficient shape retention in practice, provides easy installation and pipe shell-like usability, at the same time is inexpensive due to its thinness, and can also be used as various external and/or internal covering films. This objective is achieved with a new product, which is essentially a multi-layered, thin-walled, elongated pipe shell for use in the thermal insulation of pipes, which pipe shell has its own curvature with a radius perpendicular to its longitudinal direction, which pipe shell according to the invention contains several individual layers of flexible material or materials fixed to each other, at least a part of which material(s) is flexible, and the own curvature of the pipe shell is ensured by the fact that at least one flexible individual layer has a length taken in the circumferential direction that is different from an adjacent individual layer.

As we have said, the meaning of the shell is basically a shell having the shape of a tube split lengthwise along one of its components. In connection with the present invention, the term shell also includes those cases in which the longitudinal slit is a wide opening, i.e. the shell edges located on both sides along the slit do not meet, but leave free space, and those cases in which the said edges overlap each other, even to a significant extent. Thus, these also include those cases in which the overlap is so great that even the entire shell contains single or multiple overlapping layers everywhere, which in the cross section perpendicular to the longitudinal direction corresponds to an approx. spiral line shape. The cross section perpendicular to the longitudinal direction of the shell is basically approx. fits a circular shape, which it partially or completely covers, possibly multiple times with the aforementioned overlap, but we also include those cases in which the cross-section of the pipe shell does not fit a circular shape, but an ellipse, rounded polygon or other curved shape. An ellipse-like shape is advantageous, for example, when we want to surround two pipelines running closely together with a single pipe shell.

Also included are cases in which the shell surrounds not only one, but essentially several elongated space parts, and certain parts of the shell may also have a curvature in the opposite direction to other parts. For example, the shell may form a figure 8 in cross-section, with the two free shell edges at its central intersection, separated by a continuous shell section. These special shapes may be advantageous if several pipelines running in parallel are to be wrapped with a single common shell. In any case, the shell is topologically and in terms of its actual deformation properties suitable for being placed around one or more pipes, from the side of them, through the longitudinal slot, typically with the necessary degree of deformation, i.e. expansion, of the shell. The definition of a pipe shell necessarily includes the fact that the pipe shell essentially retains its aforementioned pipe shell-like shape when left alone and laid on a horizontal surface, i.e. it has the necessary degree of independent shape retention, even if it is otherwise easily deformable. The wall of the pipe shell consists of several layers and is thin in the sense that, due to its thinness, its thermal insulation against conduction is not significant compared to the total thermal insulation of conventional complete pipe thermal insulations. In thermal insulations in which this pipe shell is used, the necessary conductive thermal insulation is typically provided by other elements (e.g. a closed air layer or solid insulating materials). The elongated nature of the pipe shell means that its longitudinal dimension is at least twice the smallest transverse enclosing dimension. Furthermore, the fact that the pipe shell is thin-walled and elongated means that its longitudinal dimension is at least fifty times the thickness of its thinnest wall. The thin wall is necessary for cheapness, and the length is necessary for convenient, fast use. The pipe to be insulated can be one or more pipes or pipe fittings that can fit in the space that can be at least partially enclosed by the pipe shell, so the insulated pipe section can contain fittings, valves or other fittings, and can also have other coverings. The inherent curvature of the pipe shell means that the pipe shell has its own shape that is curved, which curvature is determined by the shape of the specific embodiments mentioned earlier. The radius of the inherent curvature is essentially perpendicular to the longitudinal direction, i.e. the pipe shell is essentially curved around the longitudinal direction as an axis, and the magnitude of the radius of curvature along each longitudinal line, i.e. each component of the shell, is typically the same, but it can be different at other points of the shell, even in terms of its sign.

The pipe shell according to the invention is characterized in that it comprises several independent layers of flexible material or materials fixed to each other. These flexible materials are, in themselves, thin films, fabrics, sheets, nets or other materials forming a single, independent layer, i.e., having independent strength, uniformly continuous, capable of transmitting force in the layer direction, which are flexible in the sense that, under the influence of the usual force in pipe shells, they bend or curve essentially without limit when standing alone, in contrast to non-flexible materials that resist these stresses essentially without deformation (or are only willing to deform in a relatively small range) or break or tear under their influence. The adjacent independent layers are fixed to each other, which fixing may be a fixing implemented by direct contact or by means of an intermediate fixing layer, in which case the intermediate fixing layer does not necessarily have an independent strength, uniformly continuous nature. The fastening between the individual layers must fasten the individual layers to each other in sufficiently many and close places and over a sufficiently large surface area, and with sufficient strength, because even partial separation of the individual layers can impair the curling or elastic effect in the pipe shell. At least some of the flexible materials mentioned are elastic, which means that they can be stretched elastically at least within a certain range, i.e. when the stretching stress is reduced or eliminated, they tend to return to their original state. Since the specific degree of stretching of the individual layers when the pipe shell is bent to a given extent also depends on the distance between the individual layers, a material with a relatively larger elastic deformation range is suitable for a relatively thicker shell than for a relatively thinner shell, so for example a relatively thicker-walled pipe shell can be made from suitable plastic films that stretch elastically over a large range. Typically elastic materials include plastic films, and typically inelastic materials include annealed metal films, which can be stretched, but this stretching is irreversible (so-called flow).

The self-curvature of the shell shell, which is free from external deforming effects and therefore has its own curved shape, is ensured at a given point of the shell shell by the fact that, in the cross-section of the shell shell containing the given point of the shell shell, perpendicular to the longitudinal direction of the shell, within the shell piece cut out with appropriate cuts around the point, at least one of the flexible individual layers, taken in the circumferential direction, differs from an adjacent individual layer, where the length of the layer taken in the circumferential direction is the length of the layer taken along the centerline of the layer, perpendicular to the longitudinal direction of the shell. The said cut is suitable if it is perpendicular to the surface of the shell shell at the point of the cut. The stronger the curvature (i.e. the smaller the radius of curvature) at a given point of the shell shell, the greater the said length difference between the two adjacent individual layers, within a given shell piece. The production of the mantle piece by the aforementioned incision perpendicular to the mantle surface ensures that the lengths of the pieces of the individual layers belonging to the same angular range of the given curvature are compared. The degree and direction of the curvature of the mantle, and with it the difference in the length along the circumference of the corresponding layers, can generally be a parameter that is characteristic of individual points of the mantle, and thus the aforementioned mantle piece should generally be understood as a rather small-sized mantle piece around the examined point of the mantle.

The advantage of the above pipe shell according to the invention is that, due to its shape and sufficient shape retention in practice, it provides easy installation and pipe shell-like usability, while at the same time, due to its thinness, it is cheap and can also be used as various external and/or internal covering films. It also has the advantage over known cast pipe shells that it can also contain non-bulking layers, which may be important for e.g. heat or fire resistance. Another advantage resulting from the thinness over cast pipe shells is that the pipe shell can typically be easily cut to size with scissors or a knife, which can be very convenient in building engineering applications.

The tube shell may be transparent or opaque, and preferably its inner and/or outer surface has a thermal radiation reflecting property. This can be achieved by using a metal vapor layer or metal foil or a suitable metallic coating applied and solidified in liquid form or by forming a suitable colored, e.g. light or white layer. For example, the wall of the tube shell may contain one or more metal layers, which may be either an inner or outer (surface) layer. The metal layer may also help with vapor sealing. The metal used is preferably aluminum. The advantage of such a coating is that it reflects the heat rays incident on it and reduces the cooling of the medium that is heated by conduction and/or convection from one side to the other side by thermal radiation, since the thermal radiation absorption and emission capacity of such layers is low.

In the following, we present some new, particularly advantageous implementation methods of the tube shell, some of which also include novelties in terms of dimensions that result in a surprising improvement in quality from the point of view of use.

In the case of use in thermal insulation, the pipe shell may sometimes be air-permeable, but it is more preferably air-tight and moisture-tight, therefore it is obviously advantageous to use a plastic structural layer in the pipe shell. At the same time, from the point of view of mechanical properties, the pipe shell can also be made of a material that is typically cheaper than plastic, namely paper of appropriate quality. In a preferred embodiment, the pipe shell contains both paper and plastic layers, because this combines the air- and moisture-tight and favorable deformation properties of the plastic film with the advantages arising from the cheapness of paper.

It is possible to have a tube shell that has a paper surface on at least part of its outward-facing surface (the outward-facing surface is the surface opposite the enclosed space). The advantage of this is that the paintable, wallpaper-like paper surface creates a favorable aesthetic effect.

In terms of elastic behavior, it is advantageous if the tube shell has at least two elastic independent layers. It is further advantageous if there is a layer, the lining layer, between two elastic independent layers, which increases the distance between them. Thus, a tube shell whose wall contains at least three layers is advantageous. A lining layer that is relatively thick and difficult to deform in the thickness direction is advantageous, but its rigid resistance to bending is low in a wide bending range. Plastic powder of appropriate size and spreading density can be advantageously used as a lining layer, since it is cheap compared to its effective layer thickness, and the layer it forms practically has no independent rigidity that could impair the elastic bending behavior. It is also advantageous to use plastic powder as a roughening surface coating of the tube shell, because it effectively reduces the size of the contact surface and thus the harmful heat conduction. As a lining layer

and/or a tube shell containing plastic powder as a surface coating can therefore be advantageous in several respects. The preferred method of attaching the plastic powder is welding or hot gluing (so-called hot melt or hot stamp).

Paper or plastic film that is creped or embossed or expanded to an effective density of less than 0.8 kg/dm ³ for the entire envelope volume can be advantageously used as a cheap lining layer, because such a layer is relatively thick in relation to its low weight and bending stiffness.

In order to reduce the contact surface of the tube shell, it may be advantageous to use a layer that is wrinkled (including corrugated, embossed, etc. embodiments) in the tube shell, in which case, for the purposes of the invention, the length of the layer in the circumferential direction is the effective length measured along the plane of the average centerline of the layer. In the presence of a wrinkled layer, it is advantageous if the wrinkled layer is attached to the adjacent layer in such a way that the attachment also fixes the shape of the individual wrinkles, at least partially, and thus essentially prevents them from extending or smoothing out, and thus helps to maintain the elastic tension in the layer.

Since paper can be damaged by splashing water or air humidity, it is advantageous in terms of long-term preservation of mechanical strength to have a tube shell that contains at least one paper layer, from which the tube shell has a preferably continuous, waterproofing, preferably plastic, layer extending towards the inner and/or outer side of the tube shell. It is possible that the waterproofing plastic layer is also an adhesive layer between the paper layer and another layer, which is advantageous in terms of minimizing material consumption. One possible embodiment of this is that the tube shell contains paper layers laminated with plastic, fixed to each other.

If the innermost and outermost independently strong, uniformly connected independent layers of the pipe shell wall have significantly different linear thermal expansion coefficients, the elasticity and self-curvature behavior of the pipe shell may change detrimentally as a function of the ambient temperature. The linear thermal expansion coefficients of the plastics that can be considered as such layers are typically more or less similar to each other, especially compared to the fact that each of them differs significantly from that of paper and

from several other, non-plastic materials. From this point of view, a pipe shell that contains both a plastic and a non-plastic flexible independent layer is advantageous, and the innermost and outermost independent, uniformly connected independent layers are either both plastic or both non-plastic. As we have said, in this context, a independently strong, uniformly connected independent layer is a layer that is capable of transmitting force in the layer direction by itself. Such a layer is, for example, a 9-micron metal foil made by rolling, but not such a layer is, for example, a 3-micron metal vapor-deposited metal layer or a thin paint layer sprayed by paint spraying, the latter of which only get a layer-like shape through their carrier layer.

Based on a similar line of thought, a pipe shell is preferred whose innermost and outermost independent solid, uniformly connected independent layers are plastic and the difference between the linear thermal expansion coefficient of the material of these two independent layers in the circumferential direction, measured at room temperature, is not greater than 40 percent of the larger value, preferably the material of these two independent layers is the same plastic.

Plastic films can generally be bent over a very wide range without the bending being permanent, whereas paper sheets tend to undergo permanent deformation after bending more than a certain amount, i.e. their neutral shape becomes a bent shape in itself. This permanent bending is sometimes disadvantageous in the case of pipe shells, as it reduces the fully elastic deformation range of the pipe shell. For example, if a pipe shell has to be spread out quite wide in order to be placed around the pipe to be insulated from the side, it is not advantageous if, after being spread out, the pipe shell “remembers” that it has been spread out and therefore does not spring back completely to its original position. From this point of view, those pipe shells are advantageous in which the truly determining elastic individual layers are plastic, and the paper or other non-plastic layer appears only as lining layers with typically lower tensile strength. These are the tube shells in which the two layers with the highest tensile strength are both plastic. From the point of view of the wide elasticity range, it is even more advantageous if the tube shell contains only plastic. Thin tube shells prepared in this way can even be folded into a ball and even then elastically return to their original shape.

As we have said, the two longitudinal free edges of the pipe shell may overlap each other, and in a known manner, the overlapping edge or the edge that overlaps after wrapping the pipe to be insulated may contain a pressure-sensitive self-adhesive adhesive, preferably covered with a release silicone paper, which serves to seal the longitudinal gap after insulation. The role of the silicone paper is to prevent unintentional adhesion until it is peeled off from the adhesive layer. This is a rather expensive and environmentally polluting solution. From this point of view, a pipe shell in which the longitudinal edge of one or more free edges contains a thermoplastic adhesive layer serving to seal the opening of the pipe shell, the activation temperature of which (i.e. making it suitable for bonding) is at least 60 degrees C is more advantageous. It may be advantageous if the wall thickness of the jacket edge provided with the free adhesive layer for bonding is smaller than the wall thickness of the rest of the jacket, in order to avoid excessively thick jacket parts resulting from overlap. One of the most advantageous embodiments of this is in which certain layers of the pipe shell extend into the jacket edge for sealing, while other layers do not. The thermoplastic adhesive layer may be any suitable hot melt adhesive or, for example, a suitably doped polyolefin plastic, which can be applied to the carrier layer by spraying or laminating or in any other suitable manner.

The pipe shell, as we said, reacts with elastic resistance to external deforming effects, the strength of which resistance can be an important parameter of the pipe shell. If we want a pipe shell that demonstrates a sufficiently strong elastic resistance, then in addition to the wall thickness, we must also ensure a sufficiently high elastic modulus of the elastic individual layers by selecting the appropriate material. From this point of view, a pipe shell that contains polyester, polyamide and/or polypropylene and/or other layers with a typically higher elastic modulus is advantageous, because these materials have a high elastic modulus, compared to, for example, soft polyethylene or soft PVC.

As we said, the free jacket edges along the longitudinal slit of the pipe shell can overlap each other. This is advantageous because during use, the elastic expansion of the pipe shell allows the overlapping spare jacket parts to be removed from the overlap, so that even a pipe with a larger cross-section than the original cross-section of the jacket can be completely enclosed in the pipe shell. Moreover, due to the elasticity, the pipe shell fits tightly to the actual pipe diameter to be insulated, if necessary within a fairly wide range. In addition to this dimensional universality, the remaining overlap ensures perfect longitudinal sealability for the installed pipe shell, e.g. by using a tape. However, if the overlap is too large, i.e. multiple, the installation of the pipe shell becomes increasingly difficult, due to the cross-sectional topology that essentially resembles a spiral shape. From this point of view, it is therefore advantageous if the free jacket edges of the tube shell along the longitudinal slit overlap each other, in such a way that the tube shell has a place where the jacket walls overlap each other in at most two layers.

Conventional insulating pipe shells made of solid insulating material are manufactured in certain conventional or standard sizes. From the point of view of versatility, it is advantageous if the own curvature diameter of the circular pipe shell is substantially the same as the conventional or standard diameter of a pipe shell made of a conventional solid insulating material. Said conventional solid insulating pipe shells usually allow a certain dimensional tolerance for the enclosed, insulated pipeline, and also have an outer diameter guaranteed within a certain margin of error. We have found that if the wall of our new type of pipe shell is sufficiently thin, it can be used inside and/or outside conventional insulating pipe shells, in a subsequent, complementary manner, without making it necessary to use a solid insulating pipe shell of a different size for this reason. In this respect, a pipe shell whose thinnest wall thickness is less than 1 mm, preferably less than 800 microns, is advantageous.

Despite the fact that, in view of the above aspect and in order to save material costs, it is obvious and possible to implement very thin-walled tube shells, since the elastic strength of the tube shell depends on the total thickness, a tube shell with a maximum wall thickness of at least 15 microns is preferred.

In the previous sections, we have seen what factors can influence the elastic strength of the pipe shell. Increasing the elastic strength, typically due to the wall thickness and/or the choice of material, entails increasing costs. Nevertheless, it may be worthwhile to increase the strength, because it can achieve certain qualitative leaps in the practical usability of the pipe shell. One of the most typical uses of the pipe shell is in which the pipe shell is placed on a horizontal pipe to be insulated, transversely to it, and then its longitudinal slit is glued. From a practical point of view, a pipe shell is advantageous which, due to its sufficient wall and layer thickness and sufficient elastic modulus of its layers, has such an elastic strength that it can hold itself around a pipe of substantially the same cross-section as its own independent cross-section, horizontally positioned, and the same length as the pipe shell. In this case, the worker does not have to hold the pipe shell between placement and gluing, which is very convenient. Also advantageous in terms of practical handling is a pipe shell that has sufficient wall and layer thickness and sufficient elastic modulus of its layers to have such an elastic force that it can hold itself in a horizontal position, supported at two points. In this case, the worker performing the insulation can install the entire pipe shell much faster and easier, for example with two hands, in one snap-on step, as opposed to a weaker pipe shell that, when held in only two places, collapses or sags between or next to the two places, because the latter can only be handled as a pipe over a shorter span at a time, although nevertheless, after installation, the latter pipe shell can also meet the purpose of the covering, and its use is still much more advantageous than a simple, flexible foil strip, the sections of which that have not yet been installed on the pipe will hang downwards due to the force of gravity. Even more advantageous is a pipe shell which, due to its sufficient wall and layer thickness and its layers having a sufficient elastic modulus, has such an elastic force that it can support itself in a horizontal position, supported at its two ends. This pipe shell supports itself along its entire length, which means that in some cases it is sufficient to support it only at its two ends, and it can form, for example, an insulating shell enclosing an air layer along its entire length, without support, especially if its longitudinal slit is glued. This can enable a very significant cost reduction.

The tube shell according to the invention, as we have seen, is very flexible and can be flexible in a wide range if the appropriate parameters are chosen correctly. Our following findings are based on this. As we have said, one of the biggest, common disadvantages of traditional tube shells is that their transportation, due to their large volume, is quite expensive. From this point of view, it is advantageous to have an embodiment of our new type of tube shell that has such a thin wall and such a wide range of flexibility that ten identical copies can be placed into each other essentially coaxially without significant permanent deformation. In a specific embodiment, the tube shell is assembled in 10 pieces, essentially coaxially placed into each other. This practically reduces the transportation and storage costs by a tenth compared to traditional tube shells. From the same point of view, it is advantageous to have an embodiment of our new type of tube shell that has such a degree of flexibility and such a wide range of flexibility that it can be spread out flat without significant permanent deformation. In this case, the tube shells can be stored and transported in a flat, full space utilization. In a specific embodiment, the tube shell is installed in a flat, spread-out state. From the same point of view, an embodiment of our new type of tube shell is advantageous, which has such a degree of flexibility and such a wide range of elasticity that it can be wound around an axis perpendicular to its longitudinal direction without significant permanent deformation. In this case, the tube shells can be stored and transported with good space utilization, and even, e.g. by tear perforation, several tube shells can be wound onto a roll one after the other. In a specific embodiment, the tube shell is installed in a coiled-up state about an axis perpendicular to its longitudinal direction.

The aforementioned coaxial arrangement of the tube shells can also be used when performing insulation, i.e. a pipe to be insulated can be covered by several tube shells arranged substantially coaxially with each other, at least partially overlapping each other in the circumferential direction, which tube shells can be in contact at the overlapping points or there can be air and/or other spacers between them.

As we have said, our objective is to present a new, cheap, easy and quick to assemble and disassemble pipe insulation system, using a thin, multi-layer pipe shell. This objective is achieved by a new thermal insulation system, which is essentially a thermal insulation system, which comprises a pipe to be insulated, a solid insulating material at least partially surrounding it, and an internal additional covering placed between the pipe and the insulating material and/or an external additional covering placed outside the insulating material, which system is new according to the invention in that it comprises the new type of pipe shell as described above as the internal and/or external additional covering.

The pipe to be insulated may be one or more pipes or pipe fittings of any kind that can fit into the space at least partially enclosed by the solid insulating material and the additional covering, so that the insulated pipe section may include fittings, valves or other fittings, and may also have some other covering. Any suitable insulating material may be used as the solid insulating material, for example, fibrous wool made of mineral, glass or plastic, extruded or expanded polystyrene, or other, preferably closed-cell plastic (e.g. polyurethane or polyolefin) foam, etc. The pipe to be insulated is surrounded by the solid insulating material at least partially, i.e. at least in part of the longitudinal extent and at least in part of the circumferential extent, continuously or non-continuously, directly or indirectly. In the case of an internal additional coating placed between the pipe to be insulated and the solid insulating material, the additional coating at least partially separates the pipe and the insulating material from each other, while the external additional coating placed outside the insulating material is at least partially separated from the pipe by the insulating material, and in both cases the additional coating may have longitudinal and/or circumferential sections that are free from the insulating material, and the insulating material may also have longitudinal and/or circumferential sections that are free from the additional coating. Thus, it is possible, for example, that a pipe section to be insulated has an internal and/or external additional coating along its entire length, but only has a solid thermal insulation coating along certain longitudinal sections, or vice versa. The role of the external additional coating in thermal insulation is e.g. reflection of heat rays, reduction of radiation heat loss, mechanical and protection of the insulation material from ultraviolet radiation, prevention of moisture, air and vapor flow, ensuring proper aesthetic appearance and/or cleanability, prevention of dusting of the insulation material and the resulting airborne environmental pollution, etc. The role of the internal additional coating in thermal insulation is e.g. reflection of heat rays, reduction of radiation heat loss and gas sealing. The use of the new type of pipe shell according to the invention as an additional coating is more advantageous than previous solutions because it is cheaper than solid cast pipe shells and is more practical due to its thinness, while compared to the flexible foils previously used by winding, the pipe shell ensures simple and quick assembly and disassembly due to its nature, which ultimately results in further cost reduction in connection with the implementation or use of the system.

The system can be applied, for example, by snapping on the pipe to be insulated as an internal additional covering (i.e. by placing it laterally in relation to the longitudinal direction of the pipe through its longitudinal slit, with the necessary expansion), then fixing the solid insulating material (e.g. foam pipe sheath) in the appropriate places and in the appropriate manner, and wrapping it from the outside by snapping on the pipe sheath serving as an external additional covering, if necessary. In another possible application method, the pipe sheath is associated with the solid insulating material in advance, they are fitted together and fixed together if necessary, and then the insulation is placed on the pipe to be insulated. In this case, if the solid insulating material has a slit, its position is coordinated with the slit of our thin pipe sheath(s) as necessary. Of course, it is also possible to use only one of the internal and external additional coverings.

The thin pipe shell surrounds the pipe to be insulated or the cylinder of solid insulating material from the outside, preferably it fits onto their surface from the outside. This means that in the system the thin pipe shell fits onto the curved, e.g. cylindrical, body contained therein, and takes on its radius of curvature. However, the inherent curvature characteristic of the thin pipe shell's own original curved shape may be the same as, greater than, or smaller than this curvature, and in the latter cases the thin pipe shell is elastically deformed in the installed state compared to its own original curved shape. This allows a certain thin pipe shell to be applied to bodies of different curvatures (i.e. pipes to be insulated or solid insulating materials) in a relatively wide range and to be fitted onto their surfaces. This achieves a significant reduction in the number of thin pipe shell types that need to be manufactured and stored, which results in cost savings. Part of the circumferential size, i.e. the spread-out width, of the thin pipe shell can be taken up by the previously mentioned overlap between the free shell edges, and thus the circumference of the thin pipe shell can be adjusted to the circumference of the curved body it actually wraps. To ensure gap-free wrapping or the overlap of the free shell edges, a system is advantageous in which the spread-out width of the thin pipe shell is greater than or essentially equal to the circumference of the pipe or solid insulation material to be insulated that it wraps. If the curvature of the wrapped body is much smaller or much larger than the curvature of the thin pipe shell itself, achieving a smooth fit may become difficult or inconvenient. E.g. A pipe of a fairly large diameter can be wrapped with a pipe shell with a fairly small own curvature diameter and a suitable multiple overlap (even on its entire circumference), but in this case, the thin pipe shell, for example typically near its free jacket edges, tends to separate from the pipe surface and tries to assume its own original curvature. In the case of reversed curvature conditions, the thin pipe shell must (and can) be forced by an external force to fit onto the pipe. Both cases can be inconvenient. Therefore, a curling thin pipe shell with any small or large own curvature radius cannot be used to wrap a given pipe comfortably, but the curvature radii should be coordinated. According to our observations, a system in which the difference between the thin pipe shell's own original curvature radius and the corresponding curvature radius of the pipe or solid insulation material to be wrapped by it is advantageous from this point of view is less than ninety percent of the larger value. The appropriate word refers to the fact that if the radius of curvature is not equal along the circumference, the radii of curvature of the places assigned to each other by the coating should be compared. Although it is not absolutely necessary, it is more advantageous in terms of usability to a degree that makes a qualitative difference if the thin pipe shell fits snugly onto the pipe or solid insulation material it covers, due to its own elastic strength, and does not have to be stretched separately. In this case, it may be sufficient to simply snap the thin pipe shell on, and it may not even be necessary to close the longitudinal slit and fix the free jacket edges relative to each other. From this point of view, a system in which the thin pipe shell's own original radius of curvature is smaller or essentially equal to the radius of curvature of the pipe or solid insulation material to be insulated that it covers is advantageous.

In addition to the previously mentioned roles of the external additional covering, the external additional covering realized with a thin pipe shell is also suitable for a further, very advantageous purpose, namely that the solid insulating material (typically having a cylindrical outer surface) it encloses can be partially or completely omitted in a part of the longitudinal section of the thin pipe shell. The essence of the matter is that the thin pipe shell takes on the shape of the envelope curve of the solid insulating material and, in those longitudinal sections where there is no solid insulating material, encloses an air space of the same shape around the pipe to be insulated as the shape of the solid insulating material in other longitudinal sections. In these sections, the enclosed air layer provides thermal insulation that is close to or even exceeds the conductive thermal insulation provided by the solid insulating material in other sections, since, as is known, the enclosed air layer is one of the best insulating materials (the solid insulating material also insulates by means of enclosed micro-air cells). In practice, the system is preferably implemented in such a way that the pipe to be insulated is insulated with the usual solid insulating material pipe shells and, as a novelty, with the thin pipe shell together, so that certain sections of the pipe to be insulated are wrapped with the solid insulating material and the sections between these sections are wrapped only with the thin pipe shell so that the thin pipe shell rests on the solid insulating material at certain longitudinal locations, wrapping it. In this case, instead of the solid insulating material, only the thin pipe shell and the enclosed air provide the insulation on significant pipe sections, and at the same time the installation of the insulation is just as simple as in the case of traditional solid insulating material pipe shells. Since a thin pipe shell of a given length can be much cheaper than the solid insulating material, this primarily has a (very significant) economic advantage. All this is made possible by the fact that the pipe shell, in addition to its thinness, has a suitable inherent curvature, flexibility, elasticity and shape retention. In such applications, depending on the temperature difference, it is generally necessary to provide the outer and/or inner surface of the thin pipe shell with radiation-reflecting properties. This preferred system is therefore such that at least some part or parts of the longitudinal section provided with the outer additional coating have an air layer enclosed in the space between the outer additional coating and the pipe to be insulated. Even more preferably, the system is such that at least some part or parts of the longitudinal section provided with the outer additional coating the space between the outer additional coating and the pipe to be insulated is free of solid insulating material. Preferably, the system is constructed such that at the junction of the thin pipe shells adjacent to each other in the longitudinal direction, a relatively short section is covered with solid insulating material, on which both thin pipe shells rest (and these preferably cover the entire solid piece of insulating material, more preferably overlapping each other to some extent), and otherwise the longitudinal sections of the system provided with the thin pipe shells are free of solid insulating material. At certain points of the pipe to be insulated, e.g. For tee or Y-shaped connections, external fixing points, valves, filters, etc., the previously common insulation solutions using solid insulation material can still be used. The longitudinal or circumferential free jacket edges of the pipe shells preferably overlap each other and the edges can be sealed with their own adhesive layer or external tape, which ensures increased dimensional stability and air tightness.

Just as solid insulating materials can be used in several layers, essentially coaxially, the system just described can also be used in this way. In this case, the systems just described in the inner layer(s) serve as the pipes to be insulated for the outer layer(s). It is advantageous if the longitudinal sections of the different coaxial layers with solid insulating materials are the same longitudinal sections, because in this way the thin pipe shells only support themselves, the accumulated load being transferred everywhere by the solid insulating materials.

As stated, our objective is to provide an inexpensive and convenient insulation system for use in the insulation of pipes and/or pipe fittings, comprising a thin-walled, multi-layered pipe shell. This objective is achieved by a novel system which is essentially a thermal insulation system for use in the thermal insulation of pipes, which thermal insulation system comprises a multilayer thin-walled, elongated pipe shell and a support element or support elements for holding the pipe shell in a state of forming an insulating air space around the pipe to be insulated, enclosed between the pipe and the pipe shell, and supporting the pipe shell at a certain supporting location or locations, in which system according to the invention the pipe shell comprises a plurality of separate layers of flexible material or materials fixed to each other, and the pipe shell has a flexible and elastic resistance to normal force action, which elastic resistance is provided by the elasticity of one or more of the flexible material or materials.

Among the terms used above, the previously detailed interpretation applies to the multi-layer thin-walled elongated pipe shell and to several independent layers of flexible material or materials fixed to each other, with the addition that in this case it is also possible that the curved shape of the pipe shell jacket is provided in part or in whole by the supporting element(s). The pipe to be insulated may be one or more pipes or pipe fittings of any kind that can fit in the space at least partially enclosed by the pipe shell supported by the supporting elements, so that an enclosed insulating air space is created between the pipe or pipe fitting to be insulated and the pipe shell, so that the insulated pipe section may contain fittings, valves or other fittings, and may also have some other covering. The role of the enclosed insulating air space is to insulate against conductive heat flow. The insulating air space must be enclosed between the pipe and the pipe shell in the sense that, in a certain longitudinal section, the air space around the pipe must be bounded transversely by the pipe shell and/or the support elements at least in part of the circumference (any resulting longitudinal or circumferential openings can be closed with other means, e.g. tapes, during the insulation process). The purpose of the support elements is to support the pipe or pipe fitting to be insulated and to hold the pipe shell in relation to it. The support elements may be fixed to the pipe shell from the outset, but it is also possible that this fixing is only to be created when the pipe to be insulated is thermally insulated with the system. The support points can be formed in any suitable arrangement in the longitudinal and circumferential directions, provided that the arrangement ensures adequate support for the pipe shell, taking into account the pipe shell's own weight and shape-retaining ability. The role of the support elements is therefore to maintain the shape and position of the shell, allowing the aforementioned elastic deformation. The shell shell according to the invention is flexible against normal force, e.g. from the outside of the shell, typically by denting or bending the support between places, which means that it does not rigidly resist forces of ^the magnitude encountered in practice, nor does it break. At the same time, it has elastic resistance against the aforementioned forces, i.e. when the force decreases or ceases, it tends to return or returns to its original state, at least within a certain range. The development of a small permanent wrinkling of the shell does not affect the elastic nature, because it does not prevent the substantial recovery of the shape of the shell. As we have said, it follows from the essence of the invention that the elastic resistance of the multilayer sheath against hair removal is ensured, in addition to the fact that the sheath is multilayer, by the elastic resistance against stretching and/or compression of some flexible layer(s).

The advantage of the above meshes according to the invention is that due to the thin wall of the tube shell, they can be much cheaper than other solutions, while being convenient to use and providing good thermal insulation.

The support locations obviously occupy only a certain, preferably relatively small, proportion of the total shell surface. The support locations may be arranged essentially along longitudinal lines and/or essentially along circumferential lines, accordingly the support elements may be in the form of longitudinal ribs and/or circumferential rings, but other shapes are also possible. The inherent shape retention of the tube shell allows the support elements to be located at certain longitudinal locations, spaced apart from each other, along the longitudinal direction, and in the longitudinal sections between them the tube shell to be free of support elements and support locations. This is advantageous from a cost point of view, because typically the task can be perfectly solved with a few ring-like support elements. This is also advantageous because in the longitudinal sections free from support elements the thin tube shell can be easily cut, e.g. cut in half crosswise with scissors or a knife. The support elements are preferably such that they prevent the longitudinal flow of air, and more preferably also of steam, in the enclosed air space, thereby significantly increasing the effectiveness of the thermal insulation. The support elements are thus preferably annular bodies, which have a slot, by opening which they can be placed from the side around the pipe to be insulated, and then the slot can be closed again. From the point of view of accurate closing, a system is advantageous in which the support element is a ring with a slot, the contact surfaces of which, forming the two sides of the slot, have a form-fitting, convex and concave surface shape (preferably a convex and concave wedge shape) that prevents them from sliding on each other, fitting together in pairs. After installation, the said contact surfaces can be glued or welded together, which prevents the slot from opening further.

If the support element is a split, annular body, the inner bore of the ring fits the outer diameter of the pipe to be insulated, and the outer diameter of the ring fits the diameter of the pipe shell, or, if it is a pipe and/or pipe shell with a non-circular cross-section, the shape of the support element is also modified accordingly. The support elements are preferably fixed to the pipe shell (preferably by substantially airtight contact, e.g. by welding or hot-melt bonding), and their slot is naturally in a position coordinated with the slot of the pipe shell according to the purpose. The pipe shell can thus be placed around the pipe to be insulated together with the support elements as a uniform insulating covering. In order to reduce the heat flow conducted by the support element, the support element preferably has a low thermal conductivity, preferably is made of a thermal insulating material, which, as we have said, is also preferably airtight and vapor-tight. If the supporting element does not have longitudinal air or vapor barrier capabilities, it is advantageous to use separate longitudinal air and/or vapor barrier elements.

In order to increase the thermal insulation effect, the insulation system can be used in multiple layers, which in the case of the prepared insulation means that in a given longitudinal section, the pipe shell covering the pipe to be insulated, held by the support elements, is covered from the outside by additional pipe shells held by the support elements. Thus, for the insulation system consisting of the insulating pipe shell and its support elements forming the outermost layer, the pipe to be insulated is directly connected to another insulation system consisting of a similar pipe shell and its support elements. The insulation systems can therefore be embedded in each other and fixed to each other in this way, which can happen before and/or after the pipe to be insulated is wrapped. Embedded systems increase the thermal insulation by essentially adding their individual thermal insulation effects. Since the tube shells are typically sized to support only their own weight, the support elements of adjacent nested systems are preferably arranged in line with each other, so that both sides of the tube shell section between them are in direct contact with the support element, and thus the support elements of the outermost system load the tube shell of the innermost system essentially only at the support points supported by the support elements of the innermost system. The thickness of the enclosed insulating air space of a system can preferably be between 3 mm and 30 cm, but in the case of temperature differences common in building engineering, an air layer with a thickness of between 5 mm and 35 mm provides the best insulation.

After the insulation has been prepared, the longitudinal gap of the pipe shell is not always necessary to be closed, but it is advantageous and can be closed, for example, with tape or with the adhesive layer of one of the free edges of the pipe shell. Similarly, the contact gap between adjacent pipe shells in the longitudinal direction, extending in the circumferential direction, can be closed. For this purpose, e.g., a vapor-tight, self-adhesive plastic tape can be used.

A pipe shell preferably includes at least two support elements and a longitudinal air gap, since this ensures the correct position of the entire length of the pipe shell relative to the pipe to be insulated and the ability to mount the system on the pipe to be insulated. Since the longitudinal air gaps are preferably identical to the support elements, and thus only the section of the pipe shell itself between the support elements insulates, it seems obvious that it is advantageous to place one support element only at the two ends of the pipe shell in the longitudinal direction, since in this way the insulation of the entire pipe shell can be utilized, using the fewest possible (specifically two) support elements. A properly prepared pipe shell can indeed have the necessary independent shape retention.

However, in practical use, after insulating a significant part of a longer pipe section with several consecutively applied full-length pipe shells, the pipe remains uninsulated, and its final section, which is naturally shorter than the entire length of the pipe shell, needs to be insulated with a shortened pipe shell, for which, in the case of pipe shells made of traditional, solid insulating material, the piece of the pipe shell of the required length can be cut without any problems and used alone. If the pipe shell in question only contains a support element at both ends, it cannot be used after being shortened, since after being cut in two, no closed longitudinal air space remains. Therefore, in this case, the resulting short pipe section would have to be insulated with traditional, i.e. more expensive pipe shells. From this point of view, a new type of insulation system is more advantageous, the longitudinal extension of each of the longitudinal sections of the pipe shell free from support points is at most one third, more preferably one fifth, of the length of the pipe shell. This is advantageous because essentially up to one third (or more preferably one fifth) of the tube shell or a multiple thereof can be cut off from the tube shell (together with the supporting elements falling on it) for shortening purposes, and the remaining tube shell can be used independently. We have also recognized that it is not necessarily the most advantageous if both extreme supporting elements of the system are located at the very edge of the tube shell. Namely, when covering a longer tube with several tube shells adjacent in the longitudinal direction, this would mean that the supporting elements are not distributed evenly along the entire length, and this is not optimal from the point of view of strength behavior. In this respect, a system in which one of the outermost support elements is located substantially at the outermost edge of the pipe shell and the outermost support element on the opposite side is substantially at the same distance, in the longitudinal direction towards the inside of the pipe shell, from the corresponding edge of the pipe shell, as the average distance, free of support elements, between adjacent support elements within the pipe shell. The fact that said distances are substantially the same means that the difference between the distances is of the order of magnitude of the longitudinal extension of the support elements. This arrangement is therefore advantageous from the point of view of modularity. Such units can advantageously be used to make long pipe insulation in which longitudinally adjacent pipe shells overlap each other longitudinally, thereby improving the sealing of the joint and the uniform strength of the entire resulting shell surface.

As we have seen before, the pipe shell has a flexible and elastic resistance to normal indentation effects, and we have also seen that this effect can be adjusted to the desired extent by setting various parameters. This desired extent may depend, for example, on the possible magnitude of the assumed external effects. For example, a different degree of flexible and elastic resistance is typically required in the case where the assumed external effect acting on the pipe shell is a jet of water falling from a height at rare intervals, as in the case where a hand tool dropped during installation is to be taken into account as an external effect. It also successfully resists relatively large effects, and therefore a system is advantageous in which the pipe shell has a flexible and elastic resistance to the normal force acting on the pipe shell at a point in the middle of the longitudinal section free from support points, pressing the pipe shell to the level of the interface of the pipe to be insulated, which elastic resistance is provided by the elasticity of one or more of the flexible material or materials. Such a system not only successfully withstands the force described here, since the pipe shell elastically returns to its original shape after its cessation, but also those of greater force, since when the level of the pipe to be insulated is reached, the load from the external force is subsequently taken over by the pipe to be insulated (which is typically strong, e.g. steel pipe), protecting the pipe shell from further load increase. However, the pressing force arising very close to the support points can still damage the pipe shell, if the support element is not flexible. If the support element, yielding to the external force, bends or dents, and is thus permanently damaged, then this causes damage to the system. According to our observations, a system in which at least a part of the support elements has a flexible and elastic resistance to a normal force acting on a point of the support element at the support location, through the pipe shell, and pressing it to seventy percent of its original distance from the level of the interface of the pipe to be insulated, provides additional advantages in this regard. In this system, therefore, the point of the support element pressed by an external force, through the pipe shell, at the support location, in a direction perpendicular to the pipe shell (i.e. normal), typically towards the pipe to be insulated, to seventy percent of its original distance from the interface of the pipe to be insulated, elastically returns to its original position after the force has ceased, i.e. the support element regains its original shape. This is advantageous because in this way the support element can also participate in the elastic deformation caused by the external influence (e.g. the effect of a hand tool falling on the pipe shell). The appropriate flexibility and elasticity of the support element can be ensured in any suitable way, for example, a polyolefin ring can be used as a support element, which is foamed in a suitable proportion, preferably closed-cell, and contains sufficient additives, e.g. elastomers, which provide elasticity for the foamed polyolefin. In the case of a pipe and pipe shell with a circular cross-section, the above elastic deformation criterion means that after pressing a given outer peripheral point of the ring towards the pipe, in the radial direction, to a distance of seventy percent of its original distance from the pipe, the ring elastically regains its original shape. Even more preferably, this is also fulfilled for fifty percent instead of seventy.

As we have said, our objective is to present a new manufacturing process for a thin, multilayer tube shell. A multilayer thin-walled, elongated tube shell having a radius of curvature perpendicular to its longitudinal direction, and which tube shell comprises a plurality of separate layers of flexible material or materials fixed to each other, at least a part of which material(s) is flexible, and which tube shell has its own curvature provided that at least one flexible separate layer has a different length in the circumferential direction from that of an adjacent separate layer, can be manufactured by a manufacturing process developed for manufacturing tube shells known in the prior art, although the tube shell can be manufactured for a purpose other than the present objective.

In one possible approach, a continuous tube is first made and then split along one of its components. In connection with the preparation of the tube, we can use, for example, threaded or winding in a direction perpendicular to the longitudinal axis. According to US 5,393,582, a tube is known with threaded or perpendicular, multilayer winding, wound from several layers of paper, which is strong due to the multilayer nature. As we have seen, the use of paper alone is not necessarily sufficient to achieve our goal. According to JP 6,206,669 (A2). Patent description, a coiled tube is known made by winding and heat-sealing seven layers of foil. According to JP 11,277,639 (A2). Patent description, a foil laminated with adhesive can be wound perpendicularly in several layers, heat-treated, and with this (according to our own assumption) a cylindrical tube can be made. The disadvantages of the subsequent slitting of finished cylindrical tubes as a manufacturing process are that the tube shell produced in this way can only have a circular cross-section and cannot have the desired degree of, or even significant, overlap of the free jacket edges.

The desired degree of overlap of the free sheath edges can be achieved by certain methods that can be adapted from certain known methods. US 3,620,896. Patent description describes the preparation of a curling narrow strap or an elongated but threaded spiral in such a way that two strips of different shrinkability are attached to each other as two layers, and then one layer is shrunk more than the other by heat-shrinking, whereby the strip assumes a curled shape by itself. According to the method described in US 3,904,467. Patent description, a curling narrow strap or an elongated but threaded spiral can be prepared in such a way that another layer, which is not elastically stretched in this state, is glued to an elastically stretched layer, and then the elastic stretching is released, whereby the strip assumes a curled shape by itself. These two methods can be adapted to our purpose by rolling a wide plate instead of a narrow strip in a shape curved around the width direction as an axis. Thus, by cutting off a piece of the appropriate length, a thin tube shell ensuring the desired overlap of the free jacket edges can be produced. The disadvantage of this method is that the longitudinal direction of the plate is perpendicular to the longitudinal direction of the tube shell, therefore, due to the too frequent need for cutting, the method is slow. In addition, it is also only suitable for the production of tube shells with a circular cross-section, and the tube shell's own radius of curvature can only be controlled with great difficulty.

* ^b ·· ·

A path movement in the same direction as the longitudinal direction of the elongated body with curvature is used in US 3,416,991 and US 4,151,024. Patent specification. .According to the former document, the long strip is stretched in length and a curvature is thus created in the strip by means of different transverse contractions of the layers of the strip. However, in this case, the curvature is not uniform and is not well controlled, and the feasible size range is also lower and narrower than what is currently needed. In the latter method, a multilayer strip is moved in the longitudinal direction and, in the meantime, the strip is heated from one side, whereby, due to the different heat shrinkage behavior of the layers, the strip becomes curved about the longitudinal axis. This method can be adapted to our objective, as it can also ensure the overlap of the free jacket edges, and can be carried out at high speed due to the longitudinal movement. However, the disadvantage of the method is that the production of tube shells with a cross section other than circular would only be possible with great difficulty, by deliberately designing the shrink layer unevenly, and it is also difficult to precisely control the radius of curvature. In addition, the selection of materials optimized for the manufacturing process (e.g. containing materials that shrink just right) is not necessarily optimal for subsequent usability, e.g. thermal stability, tensile strength, modulus of elasticity, vapor barrier, etc.

The previously mentioned US 3,616,123. patent specification, having a threaded self-shaped laminate, can be prepared by impregnating a plurality of fibrous, layered fabric strips with a flexible, yet uncured binder, winding the multilayer tape in a threaded manner onto a forming cylinder so that the adjacent threads are isolated from each other with a mold release agent, and then solidifying the binder in this state. The disadvantage of this method is that the resulting threaded product is unsuitable for achieving our goal. The advantage of the method, however, is that it accurately realizes the targeted geometric properties, since the flexible laminate's own curved shape will be identical to that of the forming cylinder. Another advantage is that it does not have to use shrinkable materials, so that the materials that are probably most advantageous for the final purpose of use (in the case of the document: fibrous fabrics impregnated with an elastic adhesive) can be used.

US 5,897,732., US 3,259,533., US 3,594,246. and US 4,307,053. patent specifications include methods in which the pipe to be insulated is pulled lengthwise, while a flexible thermal insulator consisting of a long strip, the width of which is adjusted to the circumference of the pipe to be insulated, is pulled together with it and bent around it, and is immediately wrapped tightly with a tape or wire in a threaded manner. The insulating material is therefore held in place solely by the wrapping. The disadvantage of this solution is that the insulating material is formed directly around the pipe to be insulated, so it is not suitable for the production of an insulating pipe shell suitable for subsequent thermal insulation according to our objective, and moreover, the insulating covering does not have an independent shape retention. The advantage of the method, however, is that the continuous movement of the narrow strip of insulating material in the longitudinal direction of the future pipe covering and the simple way of making the curvature result in a very practical, simple and fast method. Therefore, our method according to the present invention is developed by further developing this method.

Our method is therefore essentially a method for manufacturing a tube shell with a thin wall comprising several independent layers of flexible material or materials fixed to each other and having its own radius of curvature perpendicular to its longitudinal direction, during which the flexible sheath forming the wall of the tube shell, having a width appropriate to the desired spread width of the tube shell, is moved in its longitudinal direction, and in the meantime, a desired curved shape with a radius of curvature or curvatures perpendicular to the longitudinal direction is created and maintained in the flexible sheath with a fixed deflecting element or deflecting elements, and the desired curved shape is finalized, and then the tube shell is dismantled, which method is new according to the invention in that a multilayer sheath is used, and the desired curved shape is finalized by forming a final fixation between the layers of the sheath while maintaining the desired curved shape.

The characteristics of the shell, which is the subject of the objective, have already been presented earlier. The expanded size of the shell is the size of the shell shell along the circumference, perpendicular to the longitudinal direction. The flexible shell, which is moved in its longitudinal direction, is a long strip, the width of which determines the future expanded width of the shell. The length of the shell is preferably the sum of the lengths of many future shell shells to be formed from the shell. The flexibility of the shell means that during the process it can be bent around the longitudinal direction as an axis as desired, it does not rigidly resist the bending stress and does not break. The name shell refers to the fact that in the essential part of the process the shape of the shell is not flat, but curved, however, in other stages of the process, preferably e.g. at the beginning, the shell can also be a flat plate. The longitudinal movement is uniform, in the sense that longitudinal wrinkling of the jacket is avoided. The longitudinal movement is preferably a pulling movement. The longitudinal movement creates a relative displacement between the jacket and the fixed deflecting elements, whereby the deflecting elements can be used to change the curvature of the jacket. The fixed deflecting element is, for example, a funnel or other similar device, which is preferably permanently suitable for withstanding the friction of the jacket. The deflecting element is heat-resistant to the required extent, and its friction surfaces preferably contain hard chrome, Teflon or other suitable preserving and/or sliding and/or mold-releasing coating. When the desired curved shape has been created at a given location on the jacket, it is maintained for a sufficient period of time and then finalized, in order to ensure that the curvature remains in the jacket even after artificially maintaining it. As we have said, the desired curved shape of the tube shell can range from a simple split tube to a spiral cross-section with significant overlap to a very complex shape. After finalization, the jacket is unpacked, i.e., it is formed into the final tube shell product in a form that can be marketed or at least transported from the process site. The unpacking can be, for example, cutting into longer or shorter pieces.

According to the invention, the sheath is multilayer, i.e. it contains independent layers which are interconnected, have independent strength and are capable of transmitting forces in the layer direction. The layers of the sheath are arranged together during the entire process, i.e. the adjacent layers are placed next to each other and are held together by appropriate movement and guidance during the process, but are not necessarily firmly fixed to each other by independent fastening during the entire process, and preferably when forming the curves, the layers are slightly displaced relative to each other in certain places, in accordance with the curvature. After the desired curved shape is set, the shape is maintained for a certain period of time, essentially unchanged, and during this time a final fastening is formed between the said layers of the sheath, for example by firmly gluing the layers to the adjacent layers, directly or indirectly. The fastening between adjacent individual layers can be designed as a fastening by direct contact or by means of an intermediate fastening layer, in which case the intermediate fastening layer is not necessarily provided with an independent strength, uniformly continuous nature. The final fastening fastens the adjacent places of the layers to each other, but the fastening itself does not necessarily form a rigid or independently strong layer between two adjacent layers. The fastening of the adjacent layers can only be done using their own materials (e.g. if the layers themselves are sufficiently sticky) or by using an additional material, e.g. glue. With the final fastening, the curvature is therefore finalized, which thus does not suffer any significant permanent change in the further part of the process, but may typically suffer further elastic deformation, e.g. spreading, changing the layer order of the overlapping sheath parts, etc. As we said, after finalization, the curved shape does not suffer any further significant permanent deformation, i.e. the relationship of the adjacent layers determining the curvature does not change significantly, but the jacket may still experience minor permanent deformation, which, however, does not reduce the effectiveness of the procedure. Such minor changes can be caused, e.g. by linear heat shrinkage resulting from possible cooling or by small shrinkage or warping resulting from drying, etc.

The advantages of the method mentioned according to the invention are that it can be carried out quickly, the required properties of the end product can be well enforced in terms of material selection, the curvature conditions can be controlled very simply and accurately even in the case of very complex curvature, overlapping free edges can be formed within a wide range, and the method can be mechanized very simply and inexpensively. A notable advantage of the method is that it can also accurately achieve very small (e.g. a few thousandths) circumferential length differences between layers, which are necessary in the case of large curvature diameters and small wall thicknesses, in contrast to most known curling methods.

The shell has a desired cross-sectional shape, which is the curve that the shell wall assumes in a cross-section perpendicular to its longitudinal direction, at least partially or (in the case of overlapping free shell edges) even in multiple layers. This cross-sectional shape is most often circular, but it can also be many other. Due to its simple feasibility, the method is advantageous in which a baffle tube(s) with an internal longitudinal through-opening with a cross-section corresponding to the desired cross-sectional shape of the shell is used as a baffle element, and the shell is guided through the longitudinal through-opening and moved at least partially along the wall of the opening. Before the shell is introduced into the baffle tube, the curvatures in the shell are preferably formed in advance to such an extent that unwanted wrinkling of the shell is avoided when introduced into the longitudinal through-opening. The fact that the longitudinal through-hole of the baffle tube has a cross-section corresponding to the intended cross-sectional shape of the shell means that it is essentially the same, although it may be advantageous to take the wall thickness of the shell into account when designing it. Moving along the wall means that the shell is brought into contact with the wall. The wall of the baffle tube may contain a narrower or wider longitudinal slot, a discontinuity, for example, for the purpose of guiding the free edge of the shell shell (e.g. designated for free adhesive) through it, hanging out of the baffle tube. The baffle tube wall may also have other openings, e.g. perforations occupying at least a part of the wall, allowing the flow of a cooling or heating medium, preferably air. The baffle tube may also contain other necessary elements, e.g. accessories for adjusting the position and orientation, heating, cooling, lubricating the baffle tube, etc.

Also, due to its simple feasibility, the method is advantageous in which, as a guide element, a preferably elongated guide core(s) with an outer covering surface having a cross-section corresponding to the desired cross-sectional shape of the pipe shell is used, and the jacket is moved parallel to the longitudinal direction of the guide core, at least partially surrounding its covering surface, at least partially along the outer covering surface. The guide core is preferably elongated, so its longitudinal dimension is preferably larger than the smallest dimension perpendicular thereto. Before the jacket is guided around the guide core, the curvatures are preferably formed in advance to such an extent as to avoid unwanted wrinkling of the jacket when guided around the guide core. The fact that the outer covering surface of the baffle core has a cross-section corresponding to the intended cross-sectional shape of the shell means that the cross-section of the outer covering surface of the baffle core perpendicular to the longitudinal direction is essentially the same as the intended cross-sectional shape of the shell, although it may be advantageous to take the wall thickness of the shell into account when designing it. "Moving along the casing surface means that the casing is brought into contact with the casing surface. The casing surface of the baffle core may contain a narrower or wider longitudinal slit, a discontinuity, for example, for the purpose of guiding the free casing edge of the tube shell casing (e.g. designated for free adhesive) through it, bent inwardly into the baffle core. The casing surface of the baffle core may also have other openings, e.g. perforations occupying at least a part of the casing surface, allowing the flow of a cooling or heating medium, preferably air. The baffle core may also contain other necessary elements, e.g. accessories for adjusting the position and orientation, heating, cooling, lubricating the baffle core, etc.

The method in which deflecting tube(s) and deflecting core(s) are used as deflecting elements is effective and therefore advantageous, whereby the deflecting core is used at least partially inside the deflecting cylinder.

Although different guide paths or funnels can be used, the method in which the jacket is moved freely in the air in some direction between the guide elements (e.g. guide tubes and guide cores) and/or some elements that transport the jacket in a plane, e.g. roller pairs, is advantageous due to its simplicity, and by using a sufficiently long free span, the jacket is moved along the free span and is continuously transformed from one of the two different curvature states characteristic of the two ends of the free span into the other.

Due to its simplicity and clarity, the method is advantageous in which the final fixation is carried out at least partly by heating the thermoplastic adhesive in the layers and/or between the layers to a suitable degree and duration and by cooling it to a suitable degree while maintaining the curved shape. The layers themselves may be thermoplastic and may be materials suitable for bonding in a soft state, but it is also possible that a suitable adhesive (e.g. a suitable plastic powder) is introduced between the layers. The adhesive must be sufficiently heated at the latest before the end of maintaining the curved shape so that it can bond the layers that fit together in the correct curvature. During cooling, the curved shape is maintained for a sufficiently long time, essentially until the adhesive has cooled down to provide the necessary strength.

For this purpose, due to its simplicity, the method in which a deflecting element or elements heated to a suitable temperature, with a suitable circumferential uniformity and a suitable length and/or cooled with a suitable cooling power, with a suitable circumferential uniformity and a suitable length are used is advantageous. The aforementioned parameters are suitable if they ensure uniform melting of the adhesive layer along the circumference before the end of maintaining the curved shape for a sufficiently long time for the adhesive to be sufficiently distributed between the layers that are just curved and to be in a state suitable for fixation, and then ensure that the adhesive layers cool down to the required solidification everywhere before the end of maintaining the curved shape.

In terms of easier, more uniform handling of the sheath before the process or in the initial stages of the process, it is advantageous to provide a temporary fixation between the layers of the sheath before the curved shape is created, which is at least partially removed before the end of maintaining the curved shape at the latest. The role of the temporary fixation is to help keep the sheath uniform before bending. A preferred embodiment is a method in which the temporary fixation is created with a thermoplastic adhesive and is removed by heating the adhesive.

As we have said, the free edge of the sheath ending at the slit of the tube shell may contain free, i.e. uncoated adhesive, preferably thermoplastic adhesive, for the final sealing of the longitudinal slit after use. In the case of tube shells made by overlapping the edges of the sheath, it could happen that during the production the edge of the sheath is inadvertently glued together with some other point of the tube shell by the adhesive. In this regard, the method is advantageous due to its safety, in which during the formation of the curvature of the sheath containing the overlap and the subsequent steps, the edge of the sheath containing the free adhesive is brought into overlapping contact with other points of the tube shell at most on the side not containing the adhesive. The adhesive edge of the jacket, which is typically located at the innermost point at the overlap, can remain at the innermost point even in the final curved shape, but it is advantageous to use a complementary method, in which the curvature of the jacket is temporarily elastically deformed after the curved shape has been finalized, and in the meantime, by changing the layer order of the overlapping parts, the jacket edge containing free adhesive on its inner surface is made accessible from the outside. The layer order is the order of the jacket pieces as overlapping layers relative to each other at the overlap.

As mentioned, the jacket is preferably moved longitudinally by pulling, for which purpose the pulling force is applied to the part of the jacket which has already been finalized with a curved shape. It is possible to apply the pulling force to the jacket in its curved shape, or to pull the free edge of the jacket (preferably slightly folded out), but it is practically simpler and therefore advantageous to move the jacket longitudinally by pulling and to apply the pulling force to the pulling point on the section of the jacket which has already been finalized with a curved shape, so that at the pulling point the jacket is temporarily elastically deformed to a shape with a flat or at least straight cross-section. This is advantageous because in this way the jacket can be pulled between a pair of ordinary rollers and can elastically regain its previously finalized, curved shape after the pair of rollers. This method is also advantageous because during the elastic regeneration of the sheath from the above-mentioned spread-out shape after stretching, the aforementioned layer order of the overlapping parts can be easily changed as desired, e.g. due to the aforementioned considerations related to free adhesive.

During the packaging, as we said, we form the final, marketable tube shell product. The packaging can be, for example, simple cutting, but from the point of view of space usage, the method in which the tube shells are assembled coaxially in each other or flexibly spread out in a plane after being cut is advantageous. The method in which the tube shells that are consecutive in the longitudinal direction in the jacket are separated from each other by tear perforation during packaging, if required, and the jacket is flexibly rolled up is also advantageous. Tear perforation is therefore optional, since in certain cases the user may require that the actual tube shell length within the roll can be freely selected according to the resulting need. Winding can be done with or without a coil body. Winding is done in such a way (e.g. with such a radius) that the jacket is kept within the elastic deformation range.

List of figures:

Figure 1/4 shows a thin-walled tube shell, not to scale.

Figure 2/4 shows a building service water pipe insulated with solid insulation material and a thin pipe shell.

Figure 3/4 shows a thermal insulation system consisting of a pipe shell and support elements.

Figure 4/4 illustrates the process for manufacturing the tube shell, including a schematic of the manufacturing layout, in top view.

List of symbols for the figures:

./4 Figure:

101 thin-walled tube shell

102 cross-sections of tube shells

103 tube shell jacket

104 longitudinal slits

105 free edges of the sheath

106 longitudinal edge of free edge of sheath

107 overlapping of free sheath edges

108 width of overlap of free sheath edges

109 center of curvature of the shell

110 adhesive strips

111 radius of curvature

113 innermost layer

114 outermost layer

115 thermoplastic adhesive layers

116 tube shell end point

117 cross direction

118 shell length

119 polyester film

120 polyester foil metallized layer

121 papers

122 layers of paper laminated with polyethylene

123 polyethylene powder

124 last polyester layer

125 wall thickness

126 waterproofing layers

127 individual layers of flexible material

128 flexible independent layers ./4 Figure:

200 thermal insulation systems

201 heat-insulated pipes, water pipes

202 T-junction

203 extension flange

204 valves

205 solid insulation material

206 thick-walled tube shell section

207 T-shaped insulating element

208 valve insulating element

209 external additional cover

210 medium diameter thin tube shell

211 large diameter thin tube shell

212 interior accessory covers

213 small diameter thin tube shell

214 additional covers

215 coaxial multilayer insulation

216 intermediate space free from solid insulating material

A significant part of the longitudinal section of 217 water pipes./4 Figure:

301 thermal insulation system

302 tube shell

303 ring

304 slot in the ring

305 convex wedge shape

306 concave wedge shape

307 shell slit

308 ring inner bore

309 surface level of pipe to be insulated

Bonding between 310 rings and the tube shell

311 pipes to be insulated

312 closed insulating air space

Cross section of 313 rings

314 support! place

315 force pushing the mantle inward

316 jacket wall between two rings in the middle

317 centerline of curvature of tube shell

318 one of the outer rings

One edge of 319 tube shell

320 other edge rings

321 other edge of the shell

322 distance of other edge ring from other edge of tube shell

323 distance between rings

324 ring outer rim

325 ring center

326 radial direction

327 is the original distance of the outer edge of the ring from the surface level of the pipe to be insulated

328 the outer edge of the ring is half the original distance from the surface level of the pipe to be insulated

329 cloak, cloak wall

330 support! longitudinal section free from places ./4 Figure:

401 cloak

402 jacket width

403 aluminum foil width

One edge of 404 cape

405 free edge adhesive layer

406 delivery coil

407 longitudinal direction

408 front free span

409 free sheath edge with free adhesive layer

410 overlap between the edges of the sheathing

411 front spoiler

412 second baffle

413 last third of the front baffle

414 guide core

415 electric heaters

416 perforated wall of the second baffle

417 uniform airflow

418 rounded front of the deflector core

419 wire

420 guide core cover surface

421 inner surface of baffle tubes

422 outer surface of the guide core

423 end of second baffle

424 second free span

425 cylinder pair

426 the place where the cloak is cut

427 pipe shell to be cut off

428 part of the shell to be cut off

429 elastically recovering curved shape

430 Units nested by 10

431 deflector

Example I

The thin-walled shell according to the invention is also illustrated by the following example with the aid of Figure 1/4. Figure 1/4 shows a thin-walled shell, not to scale. The cross-section 102 of the shell 101 is circular, which is completely covered by the shell 103 of the shell, and even partially or doubly covered by the overlap 107 of the free shell edges 105 along the longitudinal slit 104. The layers contained by the tube shell 101, from the outside inwards: 12 micron thick polyester film 119, with a metallized layer 120, with the metallized half towards the centre of the curvature 109 of the tube shell 101, 90 gram/m ² weight paper 121, laminated with 12 gram/m ² weight polyethylene 122, with its polyethylene layer towards the said polyester film 119, 20 gram/m ² weight polyethylene powder layer 123, with a size of 100..300 microns, provided with an adhesion-enhancing additive, 121 paper 121 of similar quality, laminated with polyethylene 122, with its polyethylene layer towards the centre of the curvature 109 of the tube shell 101 and finally a metallized polyester film 119 of similar quality, 120 with its metallized layer towards the aforementioned 122 polyethylene-coated paper 121. The spread width of the last polyester layer 124 is significantly smaller than the other layers, and this film no longer covers the free edge of the sheath 105 intended for the adhesive strip 110. The layers included are all flexible, but only the 119 polyester film and the 121 paper layers can be considered as 127 individual layers. The 119 polyester film layers are the most flexible individual layers, so the two 119 polyester films provide the essential flexibility, while the two 121 paper layers and the 123 powder layer provide the essential thickness, although the 121 paper layers are also flexible in the case of their layer-wise stretching due to the present thickness dimensions. The polyethylene layers 122 serve to bond the layers together as a thermoplastic adhesive. The circumferential length of each adjacent layer decreases inwardly, as is consistent with the decrease in the radius of curvature 111 of each layer. Since the radius of curvature 111 of the tube shell 101 is very large compared to the wall thickness 125, the difference in circumferential length between said adjacent layers is, for example, about 0.23%. As can be seen, there are waterproofing layers 126 around the paper layers 121. The innermost layer 113 and the outermost layer 114 are made of the same high modulus plastic. One of the free edges 105 of the jacket

The longitudinal edge 106 contains a thermoplastic adhesive layer 115 as an adhesive strip 110 for closing the longitudinal slit 104, which is laminated polyethylene 122 belonging to the paper layer 121, the activation temperature of which is 110 degrees C. The free jacket edges 105 overlap each other 107. The tube shell 101 is capable of holding itself around a tube of the same circular cross-section as its own cross-section 102, horizontally positioned, and the same length as the tube shell 101 without any deformation, loosening, or sagging. The tube shell 101, supported at its two end points 116, is capable of holding itself without any deformation, loosening, or sagging. The tube shell 101 can be flexibly spread out flat or rolled up, and when released, it regains its shape flexibly, perfectly, and immediately. The spread width of the tube shell 101, i.e. the circumferential size of its shell 103, is approximately 203 mm, the circular diameter of its cross-section 102 in its own, undeformed shape is approximately 50 mm, and consequently the width of the overlap 107 at the free shell edges 105 is approximately 46 mm in the basic state. The tube shell 101 can naturally be flexibly expanded and even narrowed in the transverse direction 117 by changing the curvature with an external force, whereby a different value can be imposed on the diameter and the size of the overlap 107. The length 118 of the tube shell 101 is 1000 mm.

2, Example

The thermal insulation system according to the invention, comprising an additional casing, is illustrated by way of example with the aid of Fig. 2/4. Fig. 2/4 shows a building service water pipe insulated with a solid insulating material and a thin pipe shell. In the thermal insulation system 200, the pipe to be insulated 201 is therefore a steel water pipe 201, with a T-shaped branch 202, a connecting flange 203 and a valve 204. The solid insulating material 205 comprises mineral wool elements as solid insulating material, which elements are thick-walled pipe shell slices 206, a T-shaped insulating material 207 and a valve insulating element 208. The solid insulating material 205 only partially surrounds the water pipe 201. The outer additional casing 209 consists of thin tube shells of medium diameter 210 according to Example 1, and thin tube shells of large diameter 211 with the same wall design as those, but with a correspondingly larger radius of self-curvature, the inner additional casing 212 consists of a thin thin tube shell of small diameter 213 with a wall thickness of 200 microns, a perfectly flexible, wrinkled inner surface, containing light crepe paper between two metallized polyester foils of appropriate radius of curvature. Each of the thin tube shells forming the additional casing 214 comprises several layers of flexible materials fixed to each other, a part of which material is flexible, and the self-curvature of these thin tube shells is ensured by the fact that the length taken in the circumferential direction of at least one of the flexible layers is different from that of an adjacent layer. The thin tube shells have their own radius of curvature 10% smaller than the radius of curvature of the pipes or tube shells directly supporting them, and thus they are perfectly stretched over them by themselves. The thin tube shell of small diameter 213 reduces the radiation heat exchange between the solid insulation material 205 and the water pipe 201. The thin tube shell of large diameter 211 and the thin tube shell of medium diameter 210 form a coaxially built-in, multi-layer insulation. In a significant part of the longitudinal section 217 of the water pipe 201, the thin tube shell of large diameter 211 forming the outermost outer additional covering 214 and the thin tube shell of medium diameter 210 inside it, as well as the space 216 between the latter and the water pipe 201 inside it, are free from solid insulation material and contain air layers.

3, Example

The thermal insulation system according to the invention, comprising a pipe shell and support elements, is illustrated by the following example with the aid of Figures 3/4. Figure 3/4 shows a thermal insulation system comprising a pipe shell and support elements. In the thermal insulation system 301 according to the example, the thin pipe shell 302 is identical to the thin pipe shell shown in Example 1. 303 It comprises 3 flexible, closed-cell, foamed polyethylene rings 303 as support elements, which have a slot 304 with a convex 305 and a concave 306 wedge-shaped surface along one of their radii. The rings 303 are glued into the pipe shell 302, with their slots 304 along the slot 307 of the pipe shell 302. Between the rings 303, the pipe shell 302 has longitudinal sections 330 free of support. The inner envelope curve of the inner bore 308 of the rings 303 is the level 309 of the surface of the pipe to be insulated 311, i.e. the rings 303 with their inner bore 308 are to be fitted tightly to the pipe to be insulated 311. The flexibility and elasticity required for the installation of the thermal insulation system 301 on the pipe to be insulated 311 are provided by both the pipe shell 302, the rings 303 and the bonding 310 between the rings 303 and the pipe shell 302. The insulating air space 312 enclosed between the pipe to be insulated 311 and the pipe shell 302 is cylindrical in shape and its cross-section is the same as the cross-section 313 of the rings 303. The support locations 314 are those surface parts of the pipe shell 302 where the rings 303 touch the pipe shell 302. The pipe shell 302 has a sufficiently high dimensional stability to permanently support its own weight on the rings 303 without deformation, whether installed horizontally or vertically. The pipe shell 302 has a flexible and elastic resistance to the force 315 pressing the shell 329 inwards, to such an extent that the shell wall 329, in the middle between two rings 303, can be pressed down to the level 309 of the surface of the pipe 311 to be insulated, or even to the center line 317 of the curvature of the pipe shell 302, and after the force is removed, the pipe shell 302 immediately regains its original shape. This flexibility of the shell 302 is provided by the flexibility of all layers, and this elasticity is provided by the elasticity of the polyester layers. One end ring 318 fits one edge 319 of the shell 302, while the other end ring 320 is spaced 322 apart from the other edge 321 of the shell 302 by the same distance 323 between the rings 303, which facilitates modular application and fractional-length construction. The rings 303, due to their composition and density, are flexible and elastic to such an extent that the outer edge 324 of the ring 303 can be pressed towards the center 325 of the ring 303, in the radial direction 326, up to half the original distance 327 from the level 309 of the surface of the pipe 311 to be insulated, and then the ring 303 elastically regains its original shape.

Example 4

The method for manufacturing a tube shell according to the invention is illustrated by way of example with reference to Figure 4/4. Figure 4/4 illustrates the method for manufacturing a tube shell, including a schematic plan view of the manufacturing arrangement. The layers of the multilayer flexible sheath 401 are: 2 layers of polyethylene-laminated paper, with the polyethylene layer on the side facing the (future) inner side of the tube shell, with the paper weight being 90 grams/ ^m2 and the polyethylene weight being 12 grams/ ^m2 , and a layer of 12 micron annealed aluminum foil, which forms the future innermost layer. The role of the polyethylene layers is to connect the other layers, the role of the paper layers is to provide strength, flexibility and elasticity, and the aluminum plays a gas barrier and radiation reflecting role. The polyethylene layers have no significant orientation and therefore do not shrink under heat. The width of the sheath 402 is 203 mm, such that the width of the aluminum foil 403 is 183 mm and the other layers are 203 mm wide, and the aluminum foil fits exactly to the edges of the other layers at one edge of the sheath 404 and leaves the polyethylene layer free at a width of 20 mm at the other edge of the sheath, which forms the free adhesive layer 405 of the free sheath edge. The method uses the sheath 401 as a starting material as a laminate with temporary fixation, i.e., uniformly glued together by the plastic layers. This laminate was produced in an earlier step by introducing the three materials onto each other and pressing them together while heating. Due to the temporary fixation, the sheath 401 can be used in the present method as a convenient, uniform material. The sheath 401 is unwound from a supply roll 406 by longitudinal pulling and then pulled in the longitudinal direction 407. The sheath 401 is pulled in the air over a first free span of 3 meters 408 after the supply roll 406, thereby creating the curved shape, i.e. ensuring the wrinkle-free development of the curvature in the sheath. Due to the temporary fastening, a certain elastic tension may still exist in the wall at this stage against the curvature. The curved shape is formed in such a way that the free sheath edge 409 with the aforementioned free adhesive layer is a layer towards the center line of the curvature of the sheath 401 at the overlap 410 between the sheath edges, and its free adhesive layer 405 does not come into contact with other sheath parts. The jacket is then passed through a first 2-meter-long guide tube 411 with a circular longitudinal through-opening of 50 mm internal diameter, and then immediately after that through a second 1-meter-long guide tube 412. In the last third of the first guide tube 411 and the entire length of the second guide tube 412, a single guide core 414, approximately 170 cm long, is used within the guide tubes 431. During the process, we take advantage of the fact that, due to the geometric conditions, the jacket 401 of a given width can only have the desired curved shape over the entire length of the guide tubes 431. The first baffle tube 411 is heated to a temperature of 160°C with electric heaters 415, distributed evenly along its entire length, and a perforated-walled tube is used as the second baffle tube 412, and intensive cooling is applied by uniform air flow 417 along the outer side of its perforated wall 416. As the guide core 414, a hollow cylinder with a rounded front portion 418, which is fitted with a sufficiently precise fit but does not impede the movement of the sheath 401, is used, and it is held in place against the friction force of the sheath 401, from the side of the first guide tube 411, with a '4T9' wire. A smooth cylindrical surface coated with PTFE is used as the covering surface 420 of the guide core 414. The sheath 401 is thus pulled along the inner surfaces 421 of the guide tubes 431 and the outer surfaces 422 of the guide core 414, thereby maintaining and finalizing the curved shape of the sheath 401. With the aforementioned heating, the temporary fixation between the layers is eliminated by melting the adhesive. In this phase, therefore, any possible undesirable elastic stress resulting from the previous temporary fixation is is eliminated. Then, while maintaining the desired curvature, the adhesive is solidified again by cooling between the now properly positioned curved layers, thereby forming the final attachment. The tension on the jacket 401 is applied by a pair of rollers 425 after the jacket 401 has been freely guided in the air over a second free span of 3 meters from the end of the second guide tube 423 of the second guide tube 412, and in the meantime the jacket 401 is temporarily straightened in cross-section. Then, the jacket 401 is pushed to the cutting location 426 by the pair of rollers 425, and in the meantime, at least in a part 428 of the tube shell 427 to be cut, the elastically returning curved shape 429 is formed with suitable guide elements in such a way that the free jacket edge 409 with the free adhesive layer mentioned above forms the outermost layer of the jacket 401 at the overlap 410 between the jacket edges, and its free (but not activated) adhesive layer contacts the overlapping jacket part underneath. Finally, the tube shell 427 to be cut is separated from the long jacket 401 by a transverse cut, and 10 coaxially nested units 430 are formed from the finished tube shells.

Claims (30)

• · · · · · Requirements: 1. An elongated pipe shell (101) with a multilayer thin wall (103) for use in thermal insulation of a pipe, said pipe shell (101) having an inherent curvature with a radius (111) perpendicular to its longitudinal direction, characterized in that it comprises a plurality of individual layers (127) of flexible material or materials fixed to each other, at least a part of which material(s) is elastic, and said inherent curvature of said pipe shell (101) is ensured by the fact that at least one of said elastic individual layers (128) has a length different in the circumferential direction from that of an adjacent individual layer (127). 2. A tubular shell (101) according to claim 1, characterized in that its wall (103) comprises at least three layers. 3. A pipe shell (101) according to any one of claims 1.....2, characterized in that it comprises at least one paper layer (121), from which the pipe shell (101) has a preferably continuous, waterproofing, preferably plastic, layer (122) extending towards the inner and/or outer side of the pipe shell (101). 4. The tube shell (101) according to any one of claims 1.....3, characterized in that the innermost (113) and outermost (114) independently strong, uniformly continuous individual layers (127) are plastic and the difference between the linear thermal expansion coefficient of the material of these two individual layers (113,114) in the circumferential direction, measured at room temperature, is not greater than 40 percent of the larger value, preferably the material of these two layers is the same plastic. 5. The tube shell (101) according to any one of claims 1...4, characterized in that the longitudinal edge (106) of one or more free jacket edges (105) comprises a thermoplastic adhesive layer (115) for sealing the opening (104) of the tube shell (101), the activation temperature of which is at least 60 degrees C. 6. A pipe shell (101) according to any one of claims 1 to 5, characterized in that the free jacket edges (105) along the longitudinal slit (104) overlap (107) with each other. 7. A tube shell (101) according to any one of claims 1 to 6, characterized in that its thinnest wall thickness is less than 1 mm. 8. A tube shell (101) according to any one of claims 1 to 7, characterized in that its maximum wall thickness is at least 15 microns. 9. The pipe shell (101) according to any one of claims 1 to 8, characterized in that it has such an elastic force, due to its sufficient wall and layer thickness and sufficient elastic modulus of its layers (127), that it is able to hold itself around a pipe of substantially the same cross-section as its own independent cross-section (102), positioned horizontally and of the same length as the pipe shell (101). 10. A tube shell (101) according to any one of claims 1 to 9, characterized in that it has sufficient wall and layer thickness and sufficient elastic modulus of its layers (127) to have such an elastic force that it can support itself in a horizontal position, supported at its two end points (116). 11. A tube shell (101) according to any one of claims 1 to 10, characterized in that it has such a thin wall and such a wide range of elasticity that ten identical copies (101) thereof can be placed substantially coaxially one inside the other without significant permanent deformation. 12. A tubular shell (101) according to any one of claims 1 to 11, characterized in that it has such a degree of flexibility and such a wide range of elasticity that it can be laid out flat without significant permanent deformation. 13. A tube (101) according to any one of claims 1 to 12, characterized in that it has such a degree of flexibility and such a wide range of elasticity that it can be wound around an axis perpendicular to its longitudinal direction without significant permanent deformation. 14. Thermal insulation system (200), which comprises a pipe (20*1') to be thermally insulated, a solid insulating material (205) surrounding it at least partially, and an inner (212) additional covering (214) placed between the pipe (201) to be thermally insulated and the insulating material (205) and/or an outer (209) additional covering (214) placed outside the insulating material, characterized in that the inner (212) and/or outer (209) additional covering (214) comprises a thin pipe shell (101) according to any one of claims 1 to 13. 15. The system according to claim 14, characterized in that the difference between the original radius of curvature (II1) of the thin tube shell (101) and the corresponding radius of curvature of the tube (201) or solid insulation material (205) to be insulated that it encloses is less than ninety percent of the larger value. 16. The system according to any one of claims 14..... 15, characterized in that the thin pipe shell (101) has its own original radius of curvature (111) smaller than or substantially equal to the corresponding radius of curvature of the pipe (201) or solid insulating material (205) to be insulated which it encloses. 17. The system according to any one of claims 14.....16, characterized in that at least a certain part (217) or parts (217) of the longitudinal section provided with the external additional casing (209) has an air layer enclosed in the space (216) between the external additional casing (209) and the pipe (201) to be insulated. 18. The system according to any one of claims 14..... 17, characterized in that in at least a certain part (217) or parts (217) of the longitudinal section provided with the external additional casing (209), the space (216) between the external additional casing (209) and the pipe (201) to be insulated is free from the solid insulating material (205). 19. A thermal insulation system (301) for use in thermal insulation of a pipe (311), the thermal insulation system (301) comprising a multilayer thin-walled, elongated pipe shell (302) and the pipe shell (302) forming an insulating air space (312) enclosed between the pipe (311) and the pipe shell (302) around the pipe (311) to be insulated, and the pipe shell (302) being supported by a certain amount of material. comprises a support member (303) or support members (303) for supporting a tube (314) at a location (314) or locations (314), characterized in that the tube shell (302) comprises a plurality of separate layers of flexible material or materials fixed to each other, and the tube shell (302) has a flexible and elastic resistance to a normal force (315), which elastic resistance is provided by the elasticity of one or more of the flexible material or materials. 20. The system according to claim 19, characterized in that the longitudinal extent of each of the longitudinal sections (330) of the tubular shell (302) free from support locations (314) is at most one third of the length of the tubular shell (302). 21. The system according to any one of claims 19...20, characterized in that one of the outermost support elements (318) is located substantially at the edge (319) of the tube shell (302) and the opposite outermost support element (320) is located at a distance (322) substantially as great, in the longitudinal direction towards the inside of the tube shell (302), from the corresponding edge (321) of the tube shell (302) as the average longitudinal distance (330) free of support elements (303) between adjacent support elements (303) within the tube shell (302). 22. A system according to any one of claims 19.....21, characterized in that the longitudinal section (330) of the pipe shell (302) free from the support locations (314) has a flexible and elastic resistance to a normal force (315) pressing the pipe shell jacket (302) to the level (309) of the interface of the pipe (311) to be insulated at a point (316) in the middle of the longitudinal section (330), which is free from the support locations (314), which elastic resistance is provided by the elasticity of one or more of the flexible material or materials. 23. The system according to any one of claims 19.....22, characterized in that at least a portion of the support elements (303) has a flexible and elastic resistance to a normal force acting on a point of the support element (303) at the support location (314), through the pipe shell (302), and pressing it to seventy percent (328) of its original distance (327) from the level (309) of the interface of the pipe (311) to be insulated. 24. A method for manufacturing a thin-walled tube shell (430) comprising several separate layers of flexible material or materials fixed to each other and having a radius of curvature perpendicular to its longitudinal direction, in which a flexible shell (401) forming the wall of the tube shell, having a width appropriate to the desired spread-out width of the tube shell, is moved in its longitudinal direction (407), and in the meantime a desired curved shape with a radius of curvature or curvatures perpendicular to the longitudinal direction (407) is created and maintained in the flexible shell (401) by means of a fixed deflecting element or deflecting elements (431,414), and the desired curved shape is finalized, and then the tube shell (430) is assembled, characterized in that a multilayer shell (401) is used and the desired curved shape is finalized by, to provide a permanent seal between the layers of the sheath (401) while maintaining the desired curved shape. 25. The method according to claim 24, characterized in that the deflecting element (431, 414) is a deflecting tube(s) (431) having an internal longitudinal through-opening with a cross-section corresponding to the desired cross-sectional shape of the tube shell (430), and the jacket (401) is guided through the longitudinal through-opening and moved at least partially along the wall (421) of the opening. 26. The method according to any one of claims 24..... 25, characterized in that the deflecting element (431,414) is preferably an elongated deflecting core(s) (414) having an outer covering surface (420) with a cross-section corresponding to the desired cross-sectional shape of the tubular shell (430), and the jacket (401) is moved parallel to the longitudinal direction (407) of the deflecting core (414), at least partially surrounding its covering surface (420), at least partially along the outer covering surface (420). 27. The method according to any one of claims 25..... 26, characterized in that the baffle tube(s) (431) and baffle core(s) (414) are used as baffle elements (431,414) in such a way that the baffle core(s) (414) is at least partially used inside the baffle tube(s) (431). 28. The method according to any one of claims 24 to 27, characterized in that the final fixing is performed at least partially by heating the thermoplastic adhesive in the layers and/or between the layers to a suitable degree and duration and cooling it to a suitable degree while maintaining the curved shape. and 29. The method according to any one of claims 24.....28, characterized in that a deflecting element or elements heated to a suitable temperature, with suitable circumferential uniformity and over a suitable length (411) and/or cooled with suitable cooling power, with suitable circumferential uniformity and over a suitable length (412) are used. 30. The method according to any one of claims 24..... 29, characterized in that the sheath (401) is moved in the longitudinal direction (407) by pulling, and the pulling force is applied to the pulling location (425) of the sheath (401) on the section of the sheath (401) having an already finalized curved shape, so that at the pulling location (425) the sheath (401) is temporarily, elastically deformed into a straight cross-section or flat shape.