IL35375A

IL35375A - Heat exchanger and method of operation thereof

Info

Publication number: IL35375A
Application number: IL35375A
Authority: IL
Original assignee: Ygnis Sa
Priority date: 1969-10-24
Filing date: 1970-09-30
Publication date: 1974-07-31
Also published as: CH526083A; FR2065497A1; AT306073B; BE757922A; IL35375A0; CH514826A; DE2047902A1; DE2047902B2; FR2065497B1; NL7015321A; NL167024B; NL167024C; GB1294730A

Description

Heat Exchanger and Method of Operation thexeof The present invention concerns a heat exchanger with a and a method of operation Its object is to provide a heat exchanger owing to its favourable heat transfer has relatively small outside dimensions and also presents better resistance to The heat exchanger hereunder is characterised in that the eleiaent under internal pressure comprises a tube whose inner and outer have the of corrugations or ribs and are approximately equal in and that supporting are provided for the purpose of limiting the expansion of the flexible tube to ensure that under longitudinal expansion stress the tube is held without the longitudinal and can only undergo within the elastic Several embodiments of the are illustrated by way of example in the accompanying drawings in 1 shows a heat exchanger in longitudinal of 2 shows part of the heat exchanger on the 3 shows a of the heat exchanger along line in with the flange cover 4 is a graph of the heat transmission coefficient plotted against the water velocity around the exchanger for three different 5 shows a longitudinal section through a heat exchanger with a helical part and a plastic supporting 6 shows a longitudinal section through another 7 shows a longitudinal section and a partial view of a third 8 shows a of the along line in A container 1 to whose outer jacket 2 are a flange 3 at one end and a plate 4 with an outlet stub 6 and a drain stub 8 at the other contains a heating connected to a cover 12 and secured to the flange 3 screws The heating element 10 comprises thin helical tube with corrugated inner and outer which a metal hose or a spring and which is loosely jacketed by a plastic tube The tube 16 is firraly connected to a hot water inlet stub 20 at one end and a hot water outlet stub 22 at the The nietal tube 16 further presents an inlet stub 24 for a second heat exchange to the plastic tube 18 is secured by a clamp supporting jacket having the of a for and 32 have the function of limiting the expansion scope of the tube The supporting jacket 30 is preferably split and held by screws 34 evenly spaced along so that the jacket is pressed against the tube turns The jacket 30 is attached at its circumference by fishplates 36 the flange The end 23 of the plastic tube rests on a supporting plate 38 The heat exchainiger with its highly effective heating which is coiled a tube in the form of a spring tube or a netal has not only of indirect heat exchange between two in closed but also that of producing service with the consumption water side passing into a storage The heat exchange surfaces of the tubes or are practically the size inside and as their wall thickness is Such preferably alloyed metal which have corrugations or ribs inside and are with used for compensators when for flexible piping subject to internal wherein the wire meshing has the function of preventing longitudinal expansion and thus any undue stress on the thin As such a tube of useful unless supported by wire only stand up to an operating pressure of a few tenths of an atmosphere without undergoing longitudinal and as a metal tube provided with wire meshing is useless as a the metal tube have a helical form of the smallest pitch possible and be arranged in an expansion li iter in the form of a supporting jacket firmly embracing the individual This arrangement prevents any longitudinal expansion and also prevents any any deflection the longitudinal axis any deformation of the tube can only occur within the elastic Tests have shown that starting and stopping of the hot water pump or opening and closing of the tap valves gives rise to pressure shocks which individual corrugations of the thin metal This involves the risk that the friction between the jacket wall 30 and the radially outermost corrugation of the metal tube may in damage the thin metal there is the possibility of chemical reaction between the For this it is expedient to arrange a plastic layer on the inner surface of the supporting jacket the tube or as in the to plastic tube b tveen roetai tube tubs also serves to conduct the to be while not impairing the circulation of the on the outside of the On the other the pressure have a cleaning as any coatings and ere dislodged by the produced and are flushed away by the tube is not to any pressure by the the if of can be heated to the softening point of the plastic without involving any shows the heat coefficient in h C plotted against the wa velocity around a for a constant velocity of the inside the The curve applies to a tube having corrugations and out and being in stretched condition and having the following 25 A Cr steel he curve applies to a straight tube of the following 22 body smallest at root of A 10 Fe The curve applies to an ordinary of the following Dimensions A 2 Material ST 35 outside diameter inside diameter wall thickness heat exchange area Velocity of water around for constant velocity of water in Temperature of water around and in averaging delta Heating Inlet Outlet Service Inlet Outlet theta 60 C As shown a container 50 contains a heating This element 55 essentially comprises a 1 thin resilient a tube plastic flange a tuba shrunk on to ribbed or tube a securing flange 6G with the necessary connection stubs for the heating 70 the service 72 and The plastic tube in conjunction with the ribbed a helical 65 for the conduction of the to be plastic tube concurrently has the function of outwardly laterally supporting the flexible heating tubs 53 arranged inside the channel Plastic tuba 64 and ribbed tube 60 and expansion ensuring that the flexible boating cannot deflect off the helical and that it can only expand or deformed within its elastic The ting SO in 6 a securing flange stubs 84 and a resilient tuba and a steel coil spring which have a circular for The function of coil spring is to support the resilient tube which is subject to internal pressure and therefore radially To prevent friction the pressure load changes the coil spring 90 is jacketed with as by a plastic tube This also rules out any formation 7 and 8 a partial of a heat 100 with water c 102 of walls and a tube The resilient metal tuba is connected to the water and by two nipples heating is in the To certainty any lateral deflection of the tube 116 s bject to elevated a element 120 is inserted into each tube Fitted along the edges of the element 120 is a piece 122 of rubber or preventing any contact with the tube The expansion in the fora of tubes a spring 120 or the it possible to use flexible tubes and hoses capable of sustaining the internal pressures arising in particular in heat exchangers for hot service insufficientOCRQuality

Claims

C l a i m s WHAT IS CLAIMED IS:

1. ) Heat exchanger having a heat-exchanging element, characterised in that the said element (16) , being subject to internal pressure, comprises a thi -walled flexible tube (16) whose inner and outer surfaces have the form of corrugations or hollow ribs and have approximately the same size, end that supporting means (30, 32) are provided for the purpose of limiting the expansion of the flexible tube (16) , so that the tube (16) cannot be deflected frora the longitudinal axis by longitudinal expansion forces and can only undergo deformation within the elastic range.

2. ) Heat exchanger according to Claim 1, characterised in that the said tube is a spring tube or a r.etal hose (15) and is coiled in helical fashion with self-checking effect.

3.) Keat exchanger according to Claiia 1 or 2 „ characterized in that the tube (15) is provided with a protection (IS), such as a plastic tube, for instance, which does not im ede the free flow of the jaedium on the outside of the tube (16) .

4. ) Eeat exchanger according to Claim 1, characterized in that the supporting roans comprise a supporting jacket (30) for the protection of the tube (16) and a protective layer, as of plastic, for instance.

5. ) Heat exchanger according to Claim 1, characterized in that each corrugation or hollow rib of the flexible tuba (16) is supported frora outside.

6. ) Heat exchanger according to Claim 1, characterized in that each corrugation or hollow rib is supported on not more than part of its circumference.

7. ) Heat exchanger according to Claim 1, characterized in that the expansion-limiting means consist of plastic or metal.

8. ) Heat exchanger according to Claim 7, characterized in that the said means comprise. a tube (64) and a helical or ribbed tuba (60) .

9. ) Heat exchanger according to Claim 8, characterized in that the helical tube (60) is secured inside the tube (64), as by shrinking.

10. ) Heat exchanger according to Claim 7, characterized in that the said means comprise a coil spring (90) which is preferably jacketed with plastic and which is arranged inside the resilient metal tube (88).

11. ) Heat exchanger according to Claim 7, characterized in that the element comprises a stretched spring tube (116) in which is arranged a former or expansion limiter (120) which may have a star-shaped cross-section, for instance, and which is preferably supported at several points against the tube wall.

12. ) Heat exchanger according to Claim 11, characterized in that the supporting surfaces are lined with plastic (122) .

13. ) Method of operating a heat exchanger according to Claim 1, characterized in that the flexible tube is caused to move by water surges in the system, with the effect that the tube cleans itself of any deposits.

14. ) Method according to Claim 13, characterized in that the pressure shocks are caused by the propulsion of the water, as by a pump, for instance. COHE ZJ?D!?K & SPISBACH P.O.BOX 33116, Tel-Aviv Attorneys for Applicants