DE4042056C2 - Device for transporting media by means of thermally insulated pipes and process for their production - Google Patents

Description

The invention relates to a device in the Oberbe handle of claim 1 mentioned genus and a Her procedure for this.

Such devices are already known (DE-OS 36 36 738, 30 18 781 and DE-PS 29 36 588) and are, for example Supply of warm gases or liquids for processing used stations. So that the medium on the way to the the processing station concerned does not cool down too much and e.g. B. with gases reaches the dew point, the cooling will cooler environment through the insulating layer, e.g. B. a mineral wool pack and one or more heating conductors reduced.

In this case, heating wires are used as heating conductors, which of them on the other hand, for example, a ribbon arrangement of three each wrapped with electrical insulation are. The wires do not serve as heating conductors, but as Power supply. In some places the insulation is removed around the veins, so that there is a contact between the relevant wire and the end of a heating wire winding can be produced. In another example of the State of the art is in fiber fabric serving as insulation incorporated a filament. Both manufacturing processes are relatively expensive and the efficiency of the Heating conductor leaves something to be desired. Another one Embodiment of the prior art is with a  Core tube a separate heating tape especially with protective conductors as Accompanying or carried in the form of a spiral without the Efficiency of the heating conductor is optimized.

The invention has for its object a device to modify this genus so that with simple Mit and the efficiency is improved with a small space requirement becomes. The device is said to have a simple structure distinguish and be easy to assemble and disassemble. The electrical energy consumed by the heating conductor should can be used optimally.

The invention is characterized in claim 1 and in Unteran further training is claimed; in the Be further improvements of the invention are specified.

In addition, in claim 10 is a preferred manufacturing claims process.

The heating conductor is a thin band-shaped material on one Core tube made of electrically insulating material applied and expediently travels along there without that the invention is limited to this helical arrangement is. The heating conductor can also be in the form of several parallel ones in the longitudinal direction on the outer surface of the core tube Individual heating conductors should be formed. Core tube and heating conductor form an integrated unit.

In the invention, the electric current through the un located indirectly on the outer jacket of the core tube wide heating tapes, which causes the heat transfer to the Optimized core tube and the heat extraction from the core tube and the  passed medium even better and easier encountered becomes. This results in significant manufacturing association folds in a small space.

Otherwise, the device can also be used as a heating device Heating the medium can be used in the core tube.

Radially around that formed from the heating conductor and the core tube The unit is the thermal and preferably also the electrical one Insulation, which is made of the thermal insulation layer and in particular there is an additional casing tube.

While the insulation layer by appropriate choice of the wall strengthen and the material has the best possible thermal insulation lier ability so that no heat energy of the heating If the conductor is lost radially outwards, the material of the Core pipe and / or its wall thickness in the case of a heater direction should be selected so that the lowest possible heat Contact resistance between the heating conductor on the outside of the core tube and the inner surface of the core tube be stands, because this means that the inside of the core tube Medium,  in particular a liquid passed through it or a gas flowing through it is heated quickly.

According to the invention, relatively wide flat bands are considered Heating conductor used, so that the heating conductor over a large area comes into contact with the outer surface of the core tube. The cross section, the material and the supply of the heating conductor electrical energy should be chosen so that the allowable Operating temperature of the core tube is not reached.

As a precautionary measure, it is recommended if in the area of the telescope a thermal sensor is arranged so that a monitor Direction detects when the heat conductor the core tube on a Heat too high a temperature, after which a precautionary circuit or reducing the supply of electrical energy to the heating ladder is to be provided.

The core tube should be made of an electrically insulating material e.g. B. thermosets, such as GRP and others, or thermoplastics, such as PVC, PP, PE, PVDF, PTFE exist.

While the use of plastic for the outer jacket tube, especially PE, is recommended, the insulating layer made of electrically insulating plastic foam, preferably PU foam. They are also polystyrene as well mineral or rock wool can also be used. The casing tube can also consist of steel, aluminum and other metals.

Copper, aluminum is recommended as the material for the heating conductor or also steel, d. H. such an electrically conductive material, due to its special electrical resistance Current flow can heat up.  

Using tubes according to the invention are in further training whole heating pipe systems can be built according to the invention. To this The purpose is to use core tubes with their end faces to be abutted and over the end parts of the neighboring core tubes attach a pipe sleeve, which the two core pipes mechanically connected. Also the pipe sockets, which a bit along the neighboring and in particular abutting core tubes should expediently made of the same material as the core tubes, especially GRP, exist and be glued to the end parts of the core tubes. In The heating conductors are expedient in this area of the end parts away. The connection of the heating conductors of the neighboring core tubes then expediently takes place through an electrical connecting line, which run radially outside the pipe sleeve and with connection clamps with the remaining heating conductors electrically connected on the core tubes. Such For this purpose, connection clamps are around the outer circumference of the Core pipes in the area of the heating conductors and in contact with them placed; they expediently have contact elements on which the electrical connection lines, for example, by a are plugged into contact sockets.

The electrical connection can also be used the heating conductor to the electrical voltage source via, for example Clipboards or electrical junction boxes respectively. The electrical "heating circuit" is conveniently over an isolating transformer galvanically from the other electrical Facilities separated. This ensures that at a destruction of the insulation the touch of a voltage leading part remains safe. Monitoring devices too for the functioning of the insulation are recommended so that if the required insulation resistance is undershot an alarm is triggered and / or the electrical current is switched off  becomes.

It has been shown that the device according to the invention itself in potentially explosive areas of zones 1 and 2 and Temperature classes T1 to T3 used without additional measures can be. In these cases, terminals / junction boxes are used Protection type "increased safety" (EExeT5) is used.

Finally, it is also possible to take measures against that the core pipes and pipe sleeves are charged statically.

Embodiments of the invention will now be described with reference to the drawing explained in more detail. Show:

Fig. 1: a schematic partial cross section through a heating device according to the invention;

Fig. 2 is a schematic side view of an end part of a core tube, on which a connection clamp is arranged, and

FIG. 2a, another type of electrical connection;

Fig. 3: a schematic cross section through the area of adjacent core tubes and pipe lines, which are connected by sleeves and an electrical connection line;

Fig. 4: partially in cross section a preferred electrical connection option for heating the heating conductor and

Fig. 5 is a side view of one of two half shells formed in the form of insulating layer;

FIGS. 6 and 7 are partial schematic views of alternate arrangements of heating conductors is provided with core tubes.

Referring to FIG. 1, the apparatus comprises a composite system of two coaxially disposed tubes, namely of the core tube 1 and the casing tube 3, on. The heating conductor 2 is wound helically in the form of a flat band and fixed, for example by gluing, onto the outer jacket of the core tube 1 . The space between the core tube 1 with the heating conductor 2 on the one hand and the jacket tube 3 is essentially completely filled by the insulating layer 4 . This can be done, for example, by foaming plastic consisting of plastic into the space between the two tubes 1 and 3 or by inserting tube segments made from thermally well-insulating and expediently also electrically insulating foam according to FIG. 5 as half-shells 4 a, 4 b . The main task of the insulating layer 4 is to keep the heat loss radially outside the core tube 1 as low as possible.

The core tube 1 expediently consists of glass fiber reinforced plastic (GRP) from which, for example, tubes of great length of several meters are produced, which are characterized by great stability, by the filament winding method. However, the invention is not limited to this; For example, plastics reinforced with carbon fibers can also be used. In addition, it is also recommended to incorporate the material of the core tube 1 such substances that reduce the thermal conductivity resistance, so that the heat generated by the heating conductors 2 on the outer surface of the core tube 1 heat can quickly pass through the core tube 1 to the inner surface thereof , if a heating function is to be performed there.

The jacket tube 3 is advantageously made of polyethylene (PE), while the insulating layer 4 is advantageously made of poly urethane foam.

In order to assemble a Rohrleitungszug of several such tubular composite systems according to Fig. 1 and to ensure that electrical to the heating conductors 2 voltage may be applied, it is recommended that a circumferentially around the outer surface of the core tube 1 is substantially completely around cross-connecting clamp 5 of pliable and electrically good conductive material, such as copper, put around so that its radial inner surface comes in good electrical contact with the band-shaped heating conductor 2 .

According to Fig. 2 a such a connection clamp is provided at the outer ends with projecting flanges 5 a 5, so that the con nection clamp 5 by compression of the two flanges 5 a towards each other by means of the locking screw 6 its reduced diameter and fixed to the core tube 1 can be spanned. A contact element 17 made of electrically conductive material is connected to the locking screw 6 . In this case, an extension designed as a clamping lug 17 a is clamped between parts of the electrically conductive locking screw 6 . The projecting part 17 can also be designed as a sleeve into which an electrical connecting line 16 , for example a bare copper wire, can be inserted and, under certain circumstances, can be soldered in. The contact member is then in the form of a so-called "cable shoe".

According to Fig. 2a, the end 2 c of the heating conductor 2 of a core tube 1 is replaced from its original position shown in broken lines 2 'from the core tube 1 , placed on the end 2 c of the heating conductor 2 of the adjacent core tube 1 overlapping and there with this soldered or welded.

According to FIG. 3, such a connection clamp 5 is arranged in the area of each end part 1 b of the core tubes 1 at those points at which heating conductors 2 are located. The end faces 1 a of the colliding core tubes 1 closest parts of the end portions 1 b may be exempted from heating conductors 2 to the mechanical connection of the two end portions 1 b by a suitably of the same material as the core tubes aufzustecken 1 existing pipe sleeve. In order to give a sufficient hold, it is advisable to push the pipe sleeve 7 onto the respective ends of the core pipes 1 by an amount which corresponds approximately to the diameter of the core pipes 1 . The electrical connecting line 16 then produces, as shown in FIG. 3 around and along the pipe sleeve 7, the electrical connection between the connection clamps 5 of the adjacent core pipes 1 and the heating conductor 2 thereof. In this connection technology, the jacket pipes 3 and the insulating layers 4 of the neighboring pipe system do not come together. The axial space between them is filled with insulating material 9, while the tube ends are 8 a an outer sleeve 8 slipped over the pipe ends 3 a of the jacket tubes 3, which is suitably made of PE. The thermoplastic PE material of the outer sleeve 8 in the region of the tube ends 8 a is with the material of the jacket tube in the region of the pipe ends 3 a thermally welded. The insulating material 9 can also consist of PU foam, mineral wool or other thermally not very conductive material. From the outside, the viewer sees a relatively smooth pipe system, although a continuous electrical connection cable is made within it.

The electrical connection to the outside of the pipe system to make and the heating conductors to the electrical voltage source to be connected, it is recommended according to FIG. 4, the lead-out of the electrical connection line 16 from the pipe system in such a way that the exposed part of the electric Ver connecting line 16 of a silicon layer surrounded and additionally coated with an electrically insulating cable protection hose 10 . The electrical connecting line 16 then leads as a connecting cable 11 to the electrical connection elements of the connection box 12 , the housing of which is expediently made of plastic and which is equipped for connection in this embodiment with two clamps. The connection box is equipped for explosion-proof systems with a partition plate 14 which separates the connection box 12 into two departments, of which connection terminals 15 for temperature sensors can be arranged in one department.

Core tubes can also be glued, welded, or screwed together or a combination thereof.

All ge with the live parts in contact materials are excellent electrical insulators, while the joints between the individual units, in particular between the radially outer jacket tubes 3 and outer sleeves 8 , in particular by welding are well sealed against the ingress of gases, so that the device can also be used in potentially explosive areas.

In a preferred embodiment according to FIG. 1, the following dimensions of the individual units are selected:

Core tube 1 : GRP
Inner diameter: DN 100
Outside diameter: 114 mm

Jacket tube 3 : PE
Inner diameter: approx. 190 mm
Outside diameter: 200 mm

Referring to FIG. 6 are in the outer casing 1 x of the core tube 1 in the longitudinal direction thereof extending parallel heating strips 2a on glued, while the outer sheath of the core tube 1 of Figure 7 is completely surrounded with a thin mantle 2 b of aluminum. this tube or tube of aluminum foil is heated by the electric current flowing in the longitudinal direction I and thus prevents undesired heat radiation from the core tube 1 to the cooler environment.

Claims (10)

1. Device for transporting media by means of thermally insulated pipes, in which the medium can be guided along a core pipe, in which at least one electrically conductive heating conductor surrounds the core pipe and in which thermal insulation is applied radially around the structural unit formed by the core pipe and the heating conductor is characterized in that the electrically conductive heating conductor is in wide contact with the outer surface of the core tube as a wide flat strip ( 2; 2 a; 2 b). 2. Device according to claim 1, characterized in that the core tube ( 1 ) consists of an electrically insulating material with low heat transfer resistance. 3. Apparatus according to claim 1 or 2, characterized in that the wide flat band ( 2 ; 2 a; 2 b) consists of copper. 4. Apparatus according to claim 1 or 2, characterized in that the wide flat band ( 2 ; 2 a; 2 b) consists of aluminum. 5. Apparatus according to claim 1 or 2, characterized in that the wide flat band ( 2 ; 2 a; 2 b) consists of steel. 6. Device according to one of the preceding claims, characterized in that the core tube ( 1 ) consists of glass fiber reinforced thermosetting plastic and is wound in the filament winding process. 7. Device according to one of claims 1-5, characterized in that the core tube ( 1 ) consists of thermoplastic material. 8. Device according to one of the preceding claims, characterized in that a bendable connecting clamp ( 5 ) made of electrically highly conductive material substantially completely surrounds the circumference of the outer circumferential surface of the core tube ( 1 ) and there with its radial inner surface in electrical contact with the wide one Ribbon ( 2 ; 2 a; 2 b) stands. 9. Device according to one of the preceding claims, characterized in that an insulating layer ( 4 ) made of PU foam is used as thermal insulation around the core tube ( 1 ) and the heating conductor (s) (s) ( 2 ) arranged thereon. 10. A method for producing a device according to claim 9, in which a structural unit is produced from the core tube and the heating conductor (s) and is then surrounded with the thermal insulation and a jacket tube, characterized in that on the core tube ( 1 ) the one or more heating conductors ( 2 ) are wound or glued and then foamed into the space between this unit and the jacket tube ( 3 ) to form the insulating layer ( 4 ).