DE2714617A1 - HEAT EXCHANGER WITH A WIRE COIL ARRANGED ON A SUPPORT TUBE - Google Patents

Description

27U617

Dr.-lng. Reimar KfDnig Dipl-Ing. Klaus Bergen

Cecilienallee 76 A Düsseldorf 3O Telephone 45ΞΠDB Patentanwälte

March 31, 1977 28 485 W.

NV Spiro Research, Helmcnd / Holland, Indumaweg 6 "Heat exchanger with wire helix arranged on a support tube"

The invention relates to heat exchangers with a helix of wire arranged helically on a support tube, the Windings extend further in radial directions than in the direction of the carrier tube axis, and in which adjacent helical windings axially partially mesh with one another as well as by one wound around the support tube with the same pitch at a distance Wire are supported against each other.

In a heat exchanger of this type known from US Pat. No. 877,252, the helical wire windings have a slimmer shape Acute-angled isosceles triangles with rounded corners, the tips of which point outwards. The ones from the Triangular legs formed, partially interlocking The flanks of adjacent helical turns form a helical groove on the outside, into which a wire is inserted that holds the turns of the helical wire is intended to protect against displacement and deformation due to external influences.

In spite of this support wire, however, they are required to form the largest possible medium for the medium to be heated or cooled exposed surface consisting of very thin wire

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Helical wire windings, at least in their areas protruding beyond the support wire, very sensitive to external influences, as they did during manufacture, but especially during storage, transport and installation of such Heat exchangers are unavoidable at the point of use.

This is all the more true as the support wire is only slightly pretensioned inserted into the groove formed by the helical windings, but not attached to the helical wires. That has as a result, even with slight displacements or deformations of a relatively small part of the helical wire windings its bias and its frictional conclusion with the Loses helical wires and then can no longer perform the task it was intended for.

Another serious disadvantage of the known heat exchanger compared to other known exchangers with helical windings lying next to one another on the support tube and tight on wire windings lying close behind one another is that as a result of the interlocking of the helical windings the circumference of the support tube can accommodate only half of the helical wire turns. The loss caused by it on the exchange surface can be achieved through the increase in the amount of a support tube of a given length to be accommodated number of helical turns are not even approximately compensated.

Finally, the triangular shape obviously chosen to enable a simple continuous winding process is also chosen of the wire windings is disadvantageous for the heat exchange, since these windings follow the thermally influenced medium offer increasingly smaller surface outside, and the temperature difference between these surface parts and the surrounding medium with increasing distance from

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The carrier tube is getting smaller and smaller, but the amount of the medium to be thermally influenced is increasing.

In contrast, the object of the invention is, on the one hand, in a heat exchanger of the type mentioned at the outset to increase the effective wire surface considerably, to make the temperature curve within the helix more favorable and on the other hand to solidify the wire coil so that they all during production, storage, transport, during the Installation and use is able to cope with unavoidable stresses.

This is achieved according to the invention in that the turns of the helical wire are designed so that they are axially parallel with outer ones The webs lie on a cylindrical surface concentric with the carrier tube axis and adjacent helical turns at least so far interlock and the support wire is wrapped around the outer circumference of the helix and attached to it is that it connects all axially parallel webs of adjacent helical turns with one another.

The support wire arranged and fastened in this way secures all the wires of the helix in their radial alignment and provides support at the same time all wire windings in the direction of the helix axis together ah. It forms a closed one with the outer spiral wire legs cylindrical grid, which withstands all practically expected external forces.

The helical wire windings can take the form of elongated rectangles, of trapezoids that taper or widen outwards, but also of their tips on the support tube have thermally conductive attached isosceles triangles. By choosing the shape of the winding, the size of the exchange area, the temperature profile, but also the winding process can be influenced within relatively wide limits.

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While for winding coils with rectangular or only slightly tapered trapezoidal Wire windings an auxiliary device for the subsequent axial sliding into one another of helical windings wound next to one another or parts of turns is required, spirals can be made with trapezoidal shapes that expand more outwardly or with their - appropriately somewhat flattened - tips resting on the support tube triangular turns without one Wind such auxiliary device in its end position on the carrier tube.

By the way, coils with the last-mentioned wire winding form have a more favorable temperature profile insofar as with as the temperature difference to the thermally influenced medium decreases, the surface offered to it increases gets bigger.

Some embodiments for the subject of the invention forming heat exchangers are shown schematically in the drawing.
Show in it:

1 shows a coil winding through a heat exchanger laid cross-section,

Fig. 2 is a longitudinal section through part of a heat exchanger with elongated rectangular helical wire windings,

3 shows a modification of the interchangeable part according to FIG. 2 in the same representation,

4 shows a longitudinal section through part of a heat exchanger with triangular helical wire windings,

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5 shows a plan view of part of a developed circumferential surface of one of the exemplary embodiments according to FIGS. 2, 3 or 4.

The heat exchanger basically consists of a pipe 1 for a flowable heat transfer medium, its temperature can be below or above the temperature of the thermally influenced medium surrounding the exchanger, one on the tube as a carrier helically wound wire coil 2 and one wound over the outer circumference of the wire coil Stiffening or head wire 3.

All wire windings are attached to the support tube 1 in a known manner by soldering or welding in such a way that for the heat transfer from the pipe wall to the wire winding results in a metallic cross-section that is at least twice that Cross-section of the helical wire corresponds. The head wire 3 is also with each turn of the helical wire that it crosses firmly connected, although the strength of the connection is more important than the conductivity of the connection.

As can be seen from FIG. 1, the turns of the wire forming the helix 2 rest on the wall of the support tube 1 with mutual spacings which are at least equal to the wire diameter. As a result, it is possible, during the continuous winding up of the helix, to axially insert the wire windings of the helical winding subsequently applied next between the wire windings of an already applied helical winding. An auxiliary device is used for this purpose, which as such is not the subject of this invention. ^{This results in an arrangement of the helical wire windings 2a, 2a 1} on the carrier tube 1, which can be seen in FIGS. 2 and 3.

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barter helical windings into one another with about a third of their axial width of their wire windings. The one in the circumferential direction adjacent parts of the wire turns of adjacent helical turns are through one over the outer Helical circumference wound and attached to all wire windings head wire 3 in the given position against tangential and axial displacements secured.

The outer legs of the helical wire windings form a stable tubular grid with the head wire, one of which is developed is shown in detail in FIG.

In the embodiment according to FIG. 2, the head wire is located 3 on the outer legs of the wire turns, while in the embodiment of FIG. 3, the head wire 3 around his Diameter is sunk in a helical groove leading from the beveled outer corners of the wire windings 2a 'lies.

In the embodiment according to FIG. 4, the wire helix consists of isosceles acute-angled-triangular wire windings, which rest with their rounded or slightly flattened tips on the support tube 1 and only with their outer parts protrude between the wire turns of an adjacent spiral turn. Such coils with only in the area of yours The outer circumference of the interlocking turns can be brought into the position shown when being wound onto the support tube, without the need for an axial displacement of the respective winding. The external picture of this one as well A wire coil solidified by a head wire 3 corresponds to the illustration in FIG. 5.

As already stated in the introduction, the invention is not limited to the shapes of the helical wire windings shown in the drawing limited.

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L e r s e i t e

Claims (3)

27U617 - τ- N.V. Spiro Research, Heimond / Holland, Indumaweg 6 claims 1.Heat exchanger with a helix made of wire arranged helically on a support tube, the turns of which extend further in radial directions than in the direction of the pipe axis, and in which adjacent helix windings partially interlock axially and are supported against each other by a wire wound around the support tube with the same pitch at a distance are, characterized in that the turns (2a, 2a ¹ 2a ") of the helical wire are designed so that they lie with outer axially parallel webs on a cylindrical surface concentric with the axis of the support tube (1), adjacent helical turns (2) at least as far interlock and the support wire (head wire) (3) is wound around the outer circumference of the helix and fastened to it in such a way that it connects all axially parallel webs of adjacent helix windings to one another. 2. Heat exchanger according to claim 1, characterized in that the head wire (3) is sunk approximately by its diameter in a groove which is formed by the beveled outer corners of the wire windings (2a ¹ ) of adjacent helical windings (2) (Fig. 3) . 3. Heat exchanger according to one of claims 1 and 2, d a characterized in that the wire windings (2a ″) of the helix (2) has the shape of isosceles widening outward from the carrier tube (1) Have triangles or trapezoids. 809840/0476