GB1576858A

GB1576858A - Air-conditioning duct in particulat for mine and tunnel workings

Info

Publication number: GB1576858A
Application number: GB2581177A
Authority: GB
Original assignee: OLDORID KUNSTOFFE GmbH
Current assignee: OLDORID KUNSTOFFE GmbH
Priority date: 1977-04-23
Filing date: 1977-06-21
Publication date: 1980-10-15
Also published as: FR2388130A1; ATA336277A; CH620497A5; DE2718186A1; ES459321A1; AT353735B

Abstract

Each duct (1, 2) consists of a flexible plastic tube which has identical end rings (4, 7) at its two ends. The end rings (4, 7), fitted into each other, of the adjacent ducts (1, 2) form a first coupling which absorbs axial forces. The second coupling consists of a sleeve (8) which surrounds the first coupling consisting of end rings (4, 7) from the outside. Each sleeve (8) is split into two halves (9, 10). A fastening (24) serves to join together the facing edges (19, 20) of the halves (9, 10). The fastening (24), which advantageously consists of lacing cord, is pulled through recesses (21, 22) in each sleeve half (9, 10). Separation of the ducts (1, 2) from one another is avoided by the second coupling even at maximum pressures. In addition, the sealing capacity of the tube connection in the couplings is improved. <IMAGE>

Description

(54) AIR-CONDITIONING DUCT, IN PARTICULAR FOR MINE AND TUNNEL WORKINGS (71) We, OLDORID - KUNGSTSTOFFE GmbH, a German Body Corporate of Breddenkampstr. / Ecke in den Kempen 4370 Marl, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to an air-conditioning duct, which is particularly suitable for use in mine and tunnel workings, the duct being of the kind having a flexible casing, made, for example, from plastics material, in the form of a pipe which bears a rigid ring at each end serving to connect the pipe to the pipe of an adjacent similar duct by cooperation with a rigid ring at an end of the latter, the cooperating end rings of two adjacent ducts, which advantageously are of the same diameter, providing, in use of the duct, a seal between the two ducts.

Flexible air-conditioning ducts for airconditioning for excavated workings with only one entrance, e.g. a driving gallery, display considerable advantages over thinwalled pipes made of sheet metal or wood, since they are easier to transport and install, and in the course of extensive research materials and treatment process have been developed which make the flexible tubing capable of adequately withstanding low and high pressures. Such pressures, which fluctuate in the range from approximately 700 to 1000 mmWS, to a great extent during gallery driving. This is due on one hand to the considerable cross-sections with which modern driving galleries are worked, and on the other hand is the result of increased demands for safety which prescribe minimum ventilation speeds in order to dilute dangerous gases in coal mines, for example, to such an extent that a detonation or explosion is avoided. Thus, duct diameters have been steadily increased and are today in the size-range up to 2000 mm. For crosssections and pressures of this kind blowers with very high output are necessary, this frequently being achieved with fans installed in cascade formation. For the safety and operational reliability of such an air-conditioning system, amongst other things the connections which are used to connect up the separate ducts are a decisive factor, and must ensure the leak-tightness of the line of ducting.

In standardised and therefore known connections the component elements mentioned in the introduction are provided, the cooperating end rings of two adjacent ducts being surrounded by a sleeve. The sleeve is generally a strip of plate which is divided axially and has a lever fastener at its edges which makes it possible to clamp the sleeve onto the rings. However, in the course of tests carried out with this type of connection it has been found that plate strips of this kind very often get lost and are therefore missing when a new installation is carried out, that they easily become bent and unusable, and that the connections fitted with such sleeves are not adequately sealed. If the high pressure in the duct is increased to the levels mentioned in the introduction, then there is also a danger that the end rings inserted into each other will spring apart and the ducts will lose their mutual connection.

The present invention aims to provide an air-conditioning duct having means for connecting it to an adjacent similar duct, which connecting means is made up of parts which cannot get lost, makes it possible to connect up the ducts with adequate strength even at maximum pressures, in order to prevent separation of the ducts, and, in a further development of the invention, affords the possibility of also improving the leak-tightness of the joints between adjacent ducts.

According to the invention an air-conditioning duct of the kind referred to is characterised in that the duct comprises a spearate sleeve surrounding each end portion of said pipe, each sleeve having a first end secured to the pipe in a region spaced from said ring and a second end disposed closer to said ring than the first end, said sleeve having means enabling its connection to the sleeve of an adjacent similar duct.

The construction of an air-conditioning duct in accordance with the invention makes it possible for the sleeves to be secured to the duct casing at the time of manufacture of the air-conditioning ducts, so that this attachment can be produced with the desired accuracy and strength. Accordingly, during installation underground sleeves no longer have to be placed round the interengaged end rings. It is only necessary to connect together the adjacent sleeves of adjacent ducts, employing devices designed to withstand the tension betwen adjacent ducts.

Preferably, and according to another characteristic of the invention, a flexible cuff is attached to the duct casing at least under one of the sleeves, and projects forwardly over the associated end. When adjacent air-conditioning ducts are connected, the cuffs attached on the outside of adjacent pipe ends are inserted in each other and act as additional seals for the joint between the ducts. In another embodiment, one cuff only is attached to each duct, this cuff being on the inner wall of the duct casing having a seal on its free outer edge which comes to rest behind the ring seal of the inner wall of the casing.

Preferably, and according to another characteristic of the invention, the means for enabling connection of the sleeve to the sleeve of an adjacent similar duct comprises a plurality of cut-outs spaced apart around the sleeve in said second end thereof the edges of said cut-outs being reinforced with eyelets, This type of fastening is particularly suitable for flexible air-conditioning ducts made of plastics material, and can therefore be fitted economically in the manufacturing factories.

Various means can be considered for completing the connection between adjacent sleeves of adjacent ducts. On one hand Sshaped hooks can be used, the ends of which, after being inserted in the eyelets, can be non-elastically deformed to enclose the eyelets. This bending together is avoided if the connection is effected with several spring safety hooks which are hooked into the cut-outs. Spring safety hooks of this kind have the advantage that in addition they cannot spring out under high tension loading. Finally, a lacing cord can be used. In this instance wire cable is suitable with a PVC sheath which renders it resistant to corrosion.

The invention will now be described, by way of example, with reference to the accompanying drawings. in which Figure 1 is a sectional side view of a first embodiment of an air-conditioning duct according to the invention connected to an adjacent similar duct, Figure 2 is a view similar to Figure 1, showing a modified embodiment of the duct of Figure 1, Figure 3 is a plan, on a reduced scale, of two air-conditioning ducts according to Figure 1 or Figure 2 connected together, and Figure 4 is a view similar to Figure 1, showing another modified embodiment of the duct of Figure 1.

Figure 1 shows two ducts 1, 2, each having a flexible casing 3, 31, respectively, made in particular from plastics sheeting, and having connecting devices.at its two ends (only one of which is shown in the Figure). The connecting device shown on duct 1 comprises a rigid terminal ring 7, which is surrounded by the wrapped-round end 5 of the duct casing 3, the end 5 being welded onto the outer surface 16 of the duct casing 3. The other duct 2 has identical connecting devices at its ends, the one shown having a terminal ring 4 surrounded by the wrapped-round end 51 of the duct casing 31, the end 51 being welded onto the outer surface 17 of the duct casing 31 Despite their rigidity, the rings 4, 7 can be forced into each other by deformation of the cross-section of the ring, so that the terminal ring 4 of the duct 2 comes to rest inside the duct casing 3 behind the terminal ring 7 of the duct 1. Since the rings are completely covered with plastics sheeting and press against each other when the ducts 1, 2, are under tension, i.e. especially when high pressure prevails in the ducts, an adequate seal from the outside is created between the rings 4 and 7. This seal is separate from those parts of the connecting device which must take up the axial stress.

Sleeves 9, 10 are used to take up the axial stress between the inter-connected ducts.

The sleeves 9, 10 surround end portions of the casings 3, 31, respectively, and are welded to regions 14, 15 of the latter at their respective first ends 12, 13. The opposite or second end of each sleeve 9, 10 is bent round at 18 and welded to the inner face of the strip of sheeting which forms the sleeve, 9 or 10. In this way a reinforced area is created adjacent the second ends of the sleeves, which face towards each other.

The two sleeves 9, 10 are connected together by fastening means engaged in a plurality of cut-outs 21, 22 formed in, and spaced apart around, the second ends of the sleeves 9, 10, respectively, (see Figure 3). The edges of the cut-outs are reinforced with metal eyelets 23.

In all the embodiments shown, the fastening means for connecting the sleeves 9, 10 is in the form of a lacing cord 24 which is drawn alternately through a cut-out 21 or 22 on the sleeve 9 or 10, respectively, round the entire circumference of the ducts, as can be seen in Figure 3. The ends of the lacing cord can be knotted together.

The fitting of the sleeves 9 and 10 in the manner shown in Figures 1 and 3 is considerably eased if the sleeves have at least one, and preferably several axial incisions, so that the segments formed by the incisions can be laid separately superimposed on one another.

In the embodiment according to Figure 2, in which the same reference numerals designate corresponding parts, on each casing 3, 31 of the ducts 1, 2, respectively, there is a cuff 25, 26 respectively. Each cuff surrounds the circumference of the duct in the form of a ring and is welded to one of its edge areas 27 or 28 at 29 or 30 respectively on the outer surface 16 or 17 of the associated casing. The opposite radial edge area projects forwards over the end ring concerned so that the arrangement shown in Figure 2 is produced after the connection of the ducts 1 and 2. The cuffs 25 and 26 are inserted in each other in such a way that their free edge areas 32, 33 are superimposed. The purpose of the cuffs is to provide an additional seal which is pressed onto the rings 4 or 7 when the two ducts are connected together.

In the embodiment according to Figure 4 only one cuff 35 is attached by a welded seam to the inner wall 36 of the casing 31 At the free end 38 of the cuff 35, which extends as far as behind the rings 4, 7 inserted inside each other, an annular seal 40 is located on the outer surface 39. This is glued on, for example, and can be made of porous rubber or plastics material. The cuff must be fitted at the downstream end 41 of the duct for blown air-conditioning, which can be deduced from the direction of the flow arrow. With suction type airconditioning the cuff must be attached to the other end of the duct. Under the flow pressure the seal 40 presses automatically against the duct casing with the necessary pressure.

WHAT WE CLAIM IS : - 1. An air-conditioning duct having a flexible casing in the form of a pipe which bears a rigid ring at each end serving to connect the pipe to the pipe of an adjacent similar duct by cooperation with a rigid ring at an end of the latter, the cooperating end rings of two adjacent ducts providing, in use of the duct, a seal between the two ducts, characterised in that the duct comprises a separate sleeve surrounding each end portion of said pipe, each sleeve having a first end secured to the pipe in a region spaced from said ring and a second end disposed closer to said ring than the first end, said sleeve having means enabling its connection to the sleeve of an adjacent similar duct.

2. An air-conditioning duct according to claim 1, in which under at least one of said sleeves a flexible cuff is attached to said pipe and projects forwardly over the associated end ring.

3. An air-conditioning duct according to claim 1, in which a cuff is attached to the inner surface of the pipe adjacent to one end thereof, projects from the pipe beyond the end ring at said end, and carries an annular seal at its free end.

4. An air-conditioning duct according to any of claims 1 to 3, in which the rings at the two ends of said pipe have the same diameter.

5. An air-conditioning duct according to any of claims 1 to 4, in which the means for enabling connection of the sleeve to the sleeve of an adjacent duct comprises a plurality of cut-outs spaced apart around the sleeve in said second end thereof.

6. An air-conditioning duct according to claim 5, in which the edges of said cutouts are reinforced with eyelets.

7. A pair of air-conditioning ducts according to claim 5 or 6 connected together end-to-end, in which adjacent sleeves of the two ducts are connected together by means of hooks, the ends of which, after insertion in the cut-outs of the two sleeves, are nonelastically deformed to enclose the cut-outs.

8. A pair of air-conditioning ducts according to claim 5 or 6 connected together end-to-end, in which adjacent sleeves of the two ducts are connected together by spring safety hooks interconnecting the cut-outs in one sleeve with the cut-outs of the other sleeve.

9. A pair of air-conditioning ducts according to claim 5 or 6 connected together end-to-end, in which adjacent sleeves of the two ducts are connected together by a lacing cord threaded through the cut-outs of the two sleeves.

10. An air-conditioning duct constructed and arranged substantially as herein described with reference to, and as illustrated in, any of Figures 1, 2 and 4 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. drawn alternately through a cut-out 21 or 22 on the sleeve 9 or 10, respectively, round the entire circumference of the ducts, as can be seen in Figure 3. The ends of the lacing cord can be knotted together. The fitting of the sleeves 9 and 10 in the manner shown in Figures 1 and 3 is considerably eased if the sleeves have at least one, and preferably several axial incisions, so that the segments formed by the incisions can be laid separately superimposed on one another. In the embodiment according to Figure 2, in which the same reference numerals designate corresponding parts, on each casing 3, 31 of the ducts 1, 2, respectively, there is a cuff 25, 26 respectively. Each cuff surrounds the circumference of the duct in the form of a ring and is welded to one of its edge areas 27 or 28 at 29 or 30 respectively on the outer surface 16 or 17 of the associated casing. The opposite radial edge area projects forwards over the end ring concerned so that the arrangement shown in Figure 2 is produced after the connection of the ducts 1 and 2. The cuffs 25 and 26 are inserted in each other in such a way that their free edge areas 32, 33 are superimposed. The purpose of the cuffs is to provide an additional seal which is pressed onto the rings 4 or 7 when the two ducts are connected together. In the embodiment according to Figure 4 only one cuff 35 is attached by a welded seam to the inner wall 36 of the casing 31 At the free end 38 of the cuff 35, which extends as far as behind the rings 4, 7 inserted inside each other, an annular seal 40 is located on the outer surface 39. This is glued on, for example, and can be made of porous rubber or plastics material. The cuff must be fitted at the downstream end 41 of the duct for blown air-conditioning, which can be deduced from the direction of the flow arrow. With suction type airconditioning the cuff must be attached to the other end of the duct. Under the flow pressure the seal 40 presses automatically against the duct casing with the necessary pressure. WHAT WE CLAIM IS : -

1. An air-conditioning duct having a flexible casing in the form of a pipe which bears a rigid ring at each end serving to connect the pipe to the pipe of an adjacent similar duct by cooperation with a rigid ring at an end of the latter, the cooperating end rings of two adjacent ducts providing, in use of the duct, a seal between the two ducts, characterised in that the duct comprises a separate sleeve surrounding each end portion of said pipe, each sleeve having a first end secured to the pipe in a region spaced from said ring and a second end disposed closer to said ring than the first end, said sleeve having means enabling its connection to the sleeve of an adjacent similar duct.