NZ208185A

NZ208185A - Continuous production of foam-insulated tube or tube bundle

Info

Publication number: NZ208185A
Application number: NZ208185A
Authority: NZ
Inventors: C Lorry; S Geige
Original assignee: Dynamit Nobel Ag
Priority date: 1983-05-18
Filing date: 1984-05-17
Publication date: 1986-05-09
Also published as: JPS6040230A; EP0126308A1; FI841991A0; IL71848A0; FI841991A; DE3318082A1; ZA843738B

Description

/ Priority Date(s): 1?. 3$ 2081 Complete Specification Filed: 5. .2^ Class: '.Ik Publication Date: .. p. P.O. Journal, No: ^P.^3.

NEW ZEALAND 1 ^ MAYl9S4_ PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION PROCESS AND APPARATUS FOR THE PRODUCTION OF A TUBE PROVIDED WITH AN INSULATING CASING FORMED OF FOAM. }i/We, DYNAMIT NOBEL AKTIENGE SELLS CHAFT, a German company, of Postfach 120 9-, 5210 Troisdorf:, Germany hereby declare the invention for which 3 / we pray that a patent maybe granted to fi&X^us, and the method by which it is to be performed, to be particularly described in and by the following statement: - - 1 - followed by page la -la- 208185 1 "PROCESS AND APPARATUS FOR THE PRODUCTION OF A TUBE PROVIDED WITH AN INSULATING CASING FORMED OF FOAM" The subject of the invention relates to a process for the continuous production of a tube or tube bundle 5 provided with a thermoplastic, foam plastics insulating casing, in which a band formed of the foam plastics is warmed for a short time on its side forming the subsequent inner side of the insulation casing until in the thermoelastic or thermoplastic condition and is then 10 deformed transverse to its longitudinal direction about a continuously introduced tube, the abutment seam is closed and it is shaped to an insulating casing by a shaping tube and then cooling is effected, and in which the band or the insulating casing is transported by means of a 15 conveyor belt. An apparatus for the carrying out of the process starts from a continuous belt for conveying of the insulating casing to be formed, a shaping tube, an arrangement for closing of the abutment seam and heating arrangements for foam band and tube.

Such processes and apparatus are known for example from British Patent Specification 1,514,369 and British Patent Specification 1,514,687. In the process according to German Patent Specification 1,514 ,687, the foam bands are first deformed to the tubular insulation casing and 25 then the tubes are introduced, the insulating casing is closed and the insulating tube withdrawn after cooling.

For this invention there exists the object of simplifying urther the known process and in particular to bring together the step of inserting the tube in the 30 insulating casing and the beginning of deformation of the foam band to the insulating case so that not only bendable tubes but also rigid tubes can be insulated by this process. Increased frictions in the region of the formation of the insulating casing occur with the high 35 desired working speeds, which then become particularly disadvantageous if the tube is led at the same time with '• v 28 FEB 1986* 2081 B 1 the insulating casing through the shaping arrangement.

According to the invention, for solution of the object and improvement of the process, it is proposed that air be introduced for formation of an air cushion between the 5 inner side of the shaping tube and the insulating casing or the conveyor belt. As a result of the introduced air and the air cushion existing as a result thereof, the friction between the walls of the shaping tube and the conveyor belt -with insulating casing being drawn 10 therethrough is reduced and at the same time an additional cooling effect is yet achieved. The process according to the invention makes possible the production of insulated tubes with insulating casings^f ormed from foam bands at very high working speeds -£and' accordingly 15 economically with very low machinery cost. The tube' to be insulated can consist of plastic, copper, aluminium, steel or the like; it can be rigid or even elastic. As thermoplastic foam plastic there come into question for example, polyolefin foams, in particular also 20 cross-linked polyolefin foams.

In some cases it is desirable to connect insulating casing and tube surface extensively. This can take place with the process according to the invention in simple manner whereby the tube is warmed on its outer 25 side so that a lamination of the foam band onto the upper surface of the tube takes .vlace. On subsequent running through the shaping apparatus, the still necessary pressure is exerted so that the surface extensive adhesive bonding results. Such a lamination has the 30 advantage that no leakage water can build up between insulating casing and tube especially with temperature exchange stressing. Also on storage, transport and assembly, no water comes to exist between insulating casing and tube so that, in this way, a moisture 35 corrosion, is even counteracted with metal tubes. Since cross-linked polyolefin foams in particular become very easily tacky by heating on the surface, it is only 2081 1 necessary to reach the welding temperature necessary for it by heating of the tube for the laminating, to be achieved in simple manner.

Starting from the known apparatuses, when carrying 5 out the process according to the invention the shaping tube for the insulating casing is provided on its inner side with channels by which a flow of air between insulating casing or conveyor belt and tube inner side is introduced. The channels are preferably arranged spread 10 over the entire length and circumference of the shaping tube on its inner side so that a uniform sufficient air-cushion is formed by the inflowing air, whicifii?reduces the~ friction of the insulating casing and the conveyor belt on the inner wall of the tube, so that the damaging of 15 the insulating casing is avoided. An advantageous further development of the apparatus according to the invention provides that the shaping tube is formed in a plurality of parts in order to enable a simple assembly and dissembly and adjustment and that the shaping tube 20 is formed with hollow chambers with the hollow chambers being provided with entry openings for the air and walls providing the inner side of the shaping tube possessing the channels as outflow openings. A pressurised air producing arrangement which produces the necessary air 25 flow for formation of the air cushion can be attached at the entry openings of the hollow chambers.

This invention is explained in the drawing with reference to an explanatory example.

There is shown FIGURE 1 a schematic representation of an apparatus for production of the tube to be provided with an insulating casing, FIGURE 2 a schematic side view with section through the shaping tube according to Figure 1, FIGURE 3 the cross-section AA according to Figure 2, FIGURE 4 the cross-section BB according to Figure 2, FIGURE 5 the cross-section CC according to Figure 2, 2081 6 and 7 a cross-section and a plan view for the run-in region for the shaping tube, with welding apparatus, according to Figure 1, 8 the view into a shaping funnel, 9 an expanded cross-section through the wall of the shaping tube, and 11 two cross-sections of a final product 12 the run-in region, in cross-section, of the shaping tube with heating arrangement for the tube. J- With the arrangement shown in Figure ;;1',, foam bari^ 1 formed of a thermoplastic deformable material can :be processed from supply rolls directly for the cladding -of tubes 4, for example hot water tubes, heating tubes for 15 floor heating etc., as insulating casings. The foam band 1 is drawn off from the supply roll over guide rollers and over a heating arrangement 2, for example infrared irradiators and brought into contact with the tube 4 in the region of guide roller 25. The tube 4 is 20 continually fed in the direction of the arrow and optionally is pre-warmed on passage through the heating arrangement 3 before the joining with the foam band. The endless circulating conveyor belt 9 which possesses a gripping function and preferably has a rough surface 25 which possesses a good gripping for the foam band .which has been softened by the heating takes up the simultaneous conveying of tube 4 and foam band 1. The conveyor belt runs around over rollers 12, 13, 14, 15 with the roller 12 being driven by the drive 10 and the 30 speed therewith being controllable. The shaping of the insulating casing takes place before the run into the shaping tube 8 which in the example shown is formed in two parts with upper part 81 and lower part 82, which are held together by means of the bolt 16. The formation of 35 the shaping tube for example with the horizontal separating joint 84 has the advantage that not only can the conveyor belt be easily changed over but also 1 FIGURE FIGURE , 5 FIGURE FIGURE FIGURE 2081 a 5 1 different thicknesses of insulating casing and also tolerances can be equalised by an adjustment of the upper part. Upper part and lower part can also be adjusted by means of parallel adjustment arrangements, for example 5 column guides. In the entry region of the shaping tube 8 there takes place a deformation which can be undertaken for example by means of a funnel 5 or otherwise by means of rollers to be seen in Figures 2 and 3. Also the funnel, which can adjoin in one piece directly onto the 10 shaping tube 8 is shown in a possible formation-by way of example in Figure 8, in front view, with the funnel ; f? • ~r-» _ . being likewise divided horizontally into.ouTpper part 5a and lower part 5b and passing over at the end, in cross section 19, into the shaping tube of the shaping tube'. 15 In the region of the termination of the deformation, the edges of the foam band closed to form the insulating casing are connected fast with one another, in particular welded, there being for this purpose for example the welding arrangement 6 provided with a warm air welding 20 apparatus with nozzle. At the same time, a marking band 7, which band serves then at the same time for reinforcing the band, can also be welded onto the weld seam. It is also possible to weld on in this region a sliding closure and to close the insulating casing with 25 it along the edges. After leaving the shaping tube, the final product is withdrawn, if necessary rolled up or stretched. In Figures 10 and 11 there are shown for example products produceable with the apparatus. It is also possible to produce with the apparatus only 30 insulating casings without tube, as shown in Figure 11.

Figure 2 shows the shaping tube according to f.' • Figure 1 in somewhat more exact representation. Moreover, in contrast to Figure 1, the shaping region is changed, contactimg rollers 21, 22 and a projection 20 35 here being provided. Instead of the welding apparatus 6, there is provided at the end of the shaping region, the welding part 17 in order to produce the seam 2081 1 connection. The deformation of the foam band 1 takes place over projections 20 and rollers 21 arranged on both sides and in the end region with the pair of rollers 22, as shown in Figure 3, which advantageously possess a 5 spirally shaped web whereby a good feed of the weld edges to the roller projection 22a is guaranteed, as well as an exact feed. The rollers 22 can advantageously be adjustably fixed^at the mounting arrangement 22, 24. The connection of the edges of the foam band, which are 10 shaped to the insulating casing, takes place -for example by means of the welding part 17, which is passed througK .the opening 18 of the shaping tube, as is tqSbel seen from Figure 2 and Figure 4. ^ 1" In Figure 6 there is shown partially ,in 15 cross-section the arrangement of the welding apparatus 6 with nozzle 6a, with which these supply the hot air for welding of the insulating casing through the opening 18 of the shaping funnel 5. The marking band 7 is supplied for example over a rounded edge of the shaping tube and 20 pressed onto the upper side of the insulating casing.

After the deformation and welding, the tube clad with the foam band as insulating casing is drawn to the discharge of the foam band with the conveyor belt 9 through the shaping tube 8.

It is also possible in th region of the entry of the tube 4 into the shaping tuh:: 3 or the shaping funnel 5, to heat for example by means of an annular nozzle 19, as shown in Figure 12 partially in cross-section, to such a temperature that there is achieved at the contact 30 position between foam band and tube the welding temperature for the foam and a lamination between insulating casing and tube is achieved. This lamination has the advantage that no leakage water can itself come to exist between insulating casing and tube, especially 35 with temperature exchange and also, on storage, transport and assembly, no water can exist, for example between the two materials. 208185 1 In order to create in the shaping tube 8 the air cushion which is to serve for the reduction of friction on drawing the insulating casing with conveyor belt through the shaping tube and which promotes 5 simultaneously the cooling of the insulating casing, in particular the weld seam, the shaping tube 8, or the upper part 81 and the lower part 82, is provided with hollow chambers 86 which with entry openings for air and with outflow openings which are the passages or channels 10 8 5 provided going through the inner wall of .the shaping tube. This arrangement for the air supply^; into the: "it. inner part of the shaping tube is for example shown partially in Figures 2, 4, 5, 6, 9 and 12.^' According to Figure 5 the upper part 81 and also the lower part 82 of 15 the shaping tube possesses an air chamber 86 extending through in the longitudinal direction of the shaping tube, which chamber possesses an entry opening 87 for air supply, for example by means of an adjoining pressurised air apparatus. The air, as shown with the arrows, can extend over the channels 85 arranged distributed in the inner wall of the shaping tube over the entire shaping tube, between the inner side of the shaping tube and the insulating casing or the conveyor belt 9 and here reduce the friction as a result of the 25 creation of the air cushion. These channels or bores 85 can, as shown partially in Figure 9, be formed inclinedly in the conveying direction, in order to favour the feed.

Only monolayer insulating casings can be produced according to the process of this invention and with this 30 apparatus, but with corresponding equipment even multilayer insulating cases with and without; tube can be produced. 20813S

Claims

WHAT WE CLAIM IS: _0_

1 1. Process for the continuous production of a tube or tube bundle provided with an insulating casing formed of thermoplastic foam plastic, wherein a band of foam plastic is heated for a short time on its side 5 forming the subsequent inner side of the insulating casing until in the thermoelastic or thermoplastic condition and then deformed transverse to its longitudinal direction about a continuously introduced tube, the abutment seam is closed and shaped to the 10 insulating casing on pulling through a shaping tube and then cooling is effected and wherein the band or the insulating casing is transported by means of a conveyor belt, characterised in that air for formation of an air cushion is introduced between the inner side of the 15 shaping tube and the insulating casing or conveyor belt.

2. Process according to claim 1, characterised in that the tube is warmed on its outer side so that a lamination between foam band and tube is achieved.

3. Apparatus for the carrying out of the process 20 according to claim 1 or 2, with a circulating belt for conveying of the insulating case to be formed, a shaping tube, an arrangement for the closing of the abutment seam and heating arrangements for foam band and tube, characterised in that the shaping tube is provided on its 25 inner side with channels by which a current of air is introduced between insulating casing or conveyor belt and inner side of the shaping tube.

4. Apparatus according to claim 3, characterising in that the shaping tube is formed in a plurality of 30 parts and with hollow chambers, with the hollow chambers being provided with an inlet opening for the air and the inner side of the walls forming shaping tubes providing the channels as outflow openings. 35 -9- 208185

5. A process for the continuous production of a tube or tube bundle provided with an insulating casing formed of thermoplastic foam plastic substantially as hereinbefore described with reference to the accompanying drawings.

6. Apparatus for producing a tube or tube bundle provided with an insulating casing formed of thermoplastic foam plastic substantially as hereinbefore described with reference to the accompanying drawings. ly Ms/their authorise*? A | PfRK t SO'"3 •