FI87832C - SKYDDSHOELJE MOT YTTRE VAERME- OCH ELDPAOVERKAN FOER STRAENGFORMIGA VAROR SAMT SAETT FOER FRAMSTAELLNING AV ETT SKYDDSHOELJE - Google Patents

Description

1 87832

The present invention relates to a flexible sheath for a conductive article for protection against external heat and fire, which may be pipes, hoses or bundles of conductors, as well as electric cables and wires for measuring control pulses. or similar for pneumatic electrical or optical transmission. The invention also relates to a method for manufacturing a protective sheath according to the invention.

Tubes, hoses or pipe nipples conducting media are used in a wide variety of technical fields. Thus, for example, high or peak pressure hoses, also called hydraulic cables, are needed for hydraulic control and drives, but they, like pipe bundles, are also energy and information carriers in pneumatic or hydraulic measuring, control or regulating technology. Such pressure transmission cables will be used wherever electrical transmission is disadvantageous or not permitted for safety reasons (risk of explosion).

In the event of a fire or similar thermal effects:: 25 hoses, pipes or nipples used, in particular in shipbuilding, but also in the chemical or petrochemical industry, efforts have been made to keep pressurized, medium-carrying hoses or pipes operational for as long as possible. after the detection of fire damage, in order to enable the necessary measuring and control measures to be carried out for safety reasons, even by means of pneumatic or hydraulic lines.

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Therefore, it is also already known to use pipe bundles with heat-resistant metal pipes, for example, to transmit measured values, control pulses or the like, or to pull these pipe bundles into the metal pipes and provide them with a corresponding thermal insulator. Notwithstanding the high cost of such embodiments and also the high installation cost of the installation, the known devices are not useful for installation technical reasons.

It is also already known to use a highly flammable plastic mixture in the jacket in connection with the structures of pipes conducting media made of thermoplastic plastics. However, this melts and dissolves at higher temperatures and, in the event of a fire, can release the tube or hose conducting the medium very quickly and thus expose it to external heat. Functionality has thus been lost.

But also in electronic energy or data transmission technology, the development of electric-20 electric cables or wires with improved fire behavior is of paramount importance. However, the raw materials used for the insulation and / or sheaths with their flame retardant additives are generally known, as is the fitting of fire-retardant or heat-damping layers to a cable or conductor structure. However, the aim is still to • improve the viability, ie to extend its duration. during which emergency operation can still be maintained ... for example to disconnect switching events. Not by raw material selection or cable or wire structure. . However, the changes made have so far not been successful; / to achieve decisive improvements in fire behavior - without taking into account the problems of, for example, modifying a cable or wire structure optimized for electrical purposes to function as required for mechanical tasks.

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It is therefore an object of the invention to find a possibility of also protecting embodiments of pipes, hoses, cables or conduits which consist of raw materials with high heat sensitivity or which contain such materials, e.g. in the event of a fire, so that operability is still possible for a sufficient time. This problem field is particularly pronounced in all cases where, as in the case of, for example, so-called hydraulic high-pressure hoses, these hoses have been fed at a pressure of, for example, 100 bar or more.

To solve this object, the sheath according to the invention comprises a single or multilayer belt immediately surrounding the conductive article, consisting of or containing predominantly such material, a metal-coated fiberglass tape winding arranged on the belt and a dense winding consisting of yarns of temperature-resistant ceramic fiber or and a jacket surrounding the winding acting as a pressure ring, which is made of heat and / 20 or refractory fiberglass braid. The particular advantages of this layer structure can be seen in the fact that e.g. the core or cable conducting the medium is protected from the immediate effect of temperature, that the layers arranged on them already distribute the heat field evenly over the hose, pipe or cable circumference and length by heat radiation or heat conduction. This protection zone, in which materials that deliberately disperse in connection with elevated temperatures, are deliberately abandoned, is further compressed or compacted like a pressure vessel. As a result, the inner layers also remain in their concentric position under the action of the heat around the medium-conducting pipe or bundle cable and the electric cable and thus act on the entire circumference against, for example, the pressure of the medium inside the hose or pipe. The service life of a hose, a corresponding pipe or a bundle cable protected by a sheath 4 37832 constructed in accordance with the invention thus increases substantially despite the high operating pressures at fire temperatures. The same applies to live conductors of an electric cable, which, for example, can last even longer than a fire when they are fitted inside a shield according to the invention.

Preferably, the protective sheath comprises a terminating outer protective shell which is non-flammable and refractory. Such an embodiment ensures, for example, in the case of hydraulic hoses 10 at temperatures above 800 ° C and operating pressures of more than 180 bar, the usability for a sufficiently long period of time.

In further developing the idea of the invention, the mica is adapted to the strip-like support partly to improve the flexibility of the protective sheath 15 and partly to increase the operational reliability. These strips are wrapped, preferably also in individual layers of different widths, then in the same or different helical directions around the tubular article. The mica coating is then preferably directed inwards.

It is expedient in the further development of the invention that the heat-reflecting metal coating of the metal-coated fiberglass strip is directed outwards, i.e. towards the possible heat source.

: 25 According to a further idea of the invention, a temperature-resistant and heat-equalizing ceramic material. the wires, fibers or strips are coated with metal.

All hitherto mentioned conductive goods and the like. . The underlying layers are subjected to the action of a heat and / or refractory fiberglass braid adjoining them, which fiberglass braid acts as a pressure ring for the underlying layers, especially in the event of fire, when it is important to ensure that the sheath is functional for a certain period of time.

5,37832

The protective sheath according to the invention is expediently produced in such a way that it comprises a terminating outer protective shell which is non-flammable or refractory. The non-flammable or refractory outer-5 shell may be formed of the desired materials. Thus, high temperature resistant fluoropolymer-based raw materials can be used, possibly also in strip form, sintered or non-sintered. If, for manufacturing reasons, extrudable materials were used, preference would also be given to those with elevated temperature resistance. Silicone rubbers have proven to be particularly suitable in this connection, e.g. for waterproof coverings.

The enamel-coated strips may preferably have different widths from layer to layer, they are suitably wrapped with seams on top of each other as the width increases outwards.

The invention is explained in more detail in connection with the flexible flame-resistant hydraulic pressure hose 20 shown as an embodiment in Fig. 1 and in connection with the experimental diagram illustrated in experiments a and b, respectively, of such a hose.

The rubber high-pressure hose 1, which is known per se, is surrounded by a layer 2 of mica or mica-containing material. Suitably, mica-coated strips 3, e.g. of glass-fiber-based ones, are used, the mica coating pointing inwards. Numeral 4 denotes a winding of one or more strips of aluminum-coated glass fiber; the metal layer acts as a heat shield 30 and is therefore directed outwards. The associated heat-dissipating sheath 5 is formed of ceramic wires or fibers 6 placed tightly around the winding 4.

The associated fiberglass braid 7, which can also be a glass fiber strip even in the case of quite larger diameters, permanently surrounds the ceramic wires and at the same time also acts on the underlying layers 2 and 4. The outwardly closing shell 8 is e.g. flame-retardant, high-tensile silicone rubber.

Despite the protective sheath constructed in several layers according to the invention and the long durations thus obtained, in the event of a fire, the hydraulic hose is still sufficiently flexible, the hose can also be installed in a space-saving manner. Namely, when the outer diameter 10 of the inner pressure hose 1 is e.g. 25 mm and the mica layer 2 is 8 mm thick, the total outer diameter of the hose protected according to the invention only increases to 55 mm.

The following experiments were performed with a protected hydraulic hose according to the invention: Experiment a

A hydraulic hose made according to Figure 1 was attached to an oil-filled tub. Five temperature sensors 9 to 13 were always placed in the same plane as the hose 1 every 10 cm, whereby the sensor 13 was immediately attached to the surface of the hose on the side facing the oil bath. The other two temperature sensors were located in the hose (sensor 14) and between the hose 1 and the layer 2 (sensor 15), the hydraulic hose was located in a depressurized space.

After ignition of the oil, a maximum temperature of about 840 ° C was reached after about three minutes. The heat source came, after a certain amount of burning hydraulic oil, went out after 15 minutes. The temperature measured in the hose 1 by the sensor 14 during the fire was about 110 ° C, the temperature measured by the sensor 30 between the hose 1 and the layer 2 was about 125 ° C. Figure 2 illustrates the test result.

Koe b

In contrast to test a, three hydraulic hoses protected according to the invention and made in accordance with Figure 1 are now tested simultaneously, in addition to which these hoses are loaded for the duration of the test, 28 minutes, at a static pressure of 190 bar.

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The experimental result is shown in Figure 3. Then the curves Temp. 9-12 repeat the temperatures around the hoses, curves T 16-18 show the temperature course of the pressure medium in the three hydraulic hoses used for the test.

These experiments show that the usability of the hose conducting the medium is maintained under the protective sheath made according to the invention when it is only insignificantly affected by the outside temperature. Despite the simultaneous high operating pressure in connection with the elevated temperature (fire), the hose remains undamaged.

However, the invention is not limited to this particularly critical case due to the simultaneous effect of fire temperature and internal pressure. Thus, any pipeline or bundle cable having a metallic or non-metallic embodiment can also be protected according to the invention. Likewise, instead of the hose 1, each electrical cable or optical cable can be provided with a protective sheath, which allows the cable to be routed safely over the fire point without being damaged or the reliability of the operation being called into question.

It is self-evident that the functionality and integrity of the cable can also be affected by a structure independent of the shield according to the invention, for example by replacing conventional insulation materials with fire-retardant or high-temperature-resistant ones.

Claims (14)

1. Flexible casing for extruded goods for protection from external heat and fire impact, which may be medium conducting pipes, hoses (1) or piping cables and electrical cables and wires for pneumatic, hydraulic, electric or optical Transmission of control pulses, measured values and the like, characterized by a single-layer or multi-layered bandage which directly encloses the stranded material (1) and which consists of mica or contains a grainy material to a large extent, an overlying wrap (4) of a metal-coated glass filament band and a sealed winding of trees, fibers or ribbons (4) of a temperature-resistant ceramic material and a casing (5, 7, 8) acting as a heat and / or fire-resistant glass filament braid surrounding the winding. Enclosure according to claim 1, characterized in that it has a closing, outer protective sheath (8) which is flammable or refractory. Housing according to claim 1 or 2, characterized in that the mica is arranged on a band-shaped support (3). A casing according to claim 3, characterized in that the mica-bearing carrier (3) is multiple-folded. 5. A casing according to claim 4, characterized in that the mica layer is turned inwards. A casing according to any of claims 1-5, characterized in that the metal coating of the glass filament band is turned leaking. A casing according to any one of claims 1-6, characterized in that the trees (6), the fibers or the bands of ceramic material are metal coated. : 35 Enclosure according to any of claims 2-7, characterized by ··. characterized in that the extruded protective jacket (8) consists of a silicone rubber. 11 8 7 832 9. A casing according to any of claims 2-7, characterized in that the protective jacket consists of a highly flammable, temperature-resistant plastic or thermoplastic. 5 10. A casing according to any of claims 2-7, characterized in that the protective jacket consists of a circular frame. A casing according to any of claims 2-7, characterized in that the protective jacket consists of an inorganic material. 12. A method of manufacturing a protective housing according to any one of claims 1 to 11, characterized in that the first ready-made pipe, hose (1), pipe bundle cable or electric cable or the wire is first cut off with mica coated band (3) a multi-layered bandage by winding, with the mica inset, and over it, a metal-coated glass filament band (4) also affixed by winding, with the metal layer eaten, that this band layer is then tightly enclosed with metal-coated ceramic trees (6) and A glass filament braid (7) and finally an outer protective jacket (8) are laid over it. 13. A method according to claim 12, characterized in that the strips (3) coated with mica have different widths from layer to layer. 14. A method according to claim 13, characterized in that the straps are wound edge to edge with leaking increasing widths.