METHOD AND APPARATUS FOR MANUFACTURING TURBULATOR MEMBERS

Technical Field

The present invention concerns a method for manufacturing turbulator members adapted to be used in heat-exchanger or similar devices, as well as an apparatus for carrying out such method.

Background Art

The use of turbulator members in heat-exchanger devices has been known.

Turbulator members, which can have different shapes, are generally inserted in the ducts of heat-exchanger devices, to produce a variation of motion of the fluid flowing inside the ducts. In particular, turbulator members are used to transform the motion of the fluid from laminar to turbulent, in order to speed up the heat transfer and to make the heating of the heat-exchanger device homogeneous.

Therefore, turbulators enhance an efficient functioning of the heat-exchanger devices, reducing the uprising of possible problems, such as for example the obstruction of the ducts, increasing the durability.

A known type of turbulator members is made up of a band, generally of metallic material, twisted on itself shaping a spiral. Such kind of turbulator member is usually used in ducts crossed by air and/or gas and/or vapour.

A second type of turbulator member, called "wire turbulator" consists of a central support element comprising at least one couple of wires reciprocally twisted and at least one external wire wound in a plurality of loops about one of the wires of the central support element, thus creating a path of helical shape. Such turbulator member is mostly used in ducts in which flow liquids such as water, oil or liquids of industrial and/or petroleum processing.

Further examples of turbulator members are known, such as for example the turbulator member disclosed in patent GB2055185. Such turbulator is of the wire type and has a plurality of loops of elongated shape that extend about the central support element shaping in its entirety a helical path.

Turbulator members are created according to methods that differ according to the type of turbulator.

Patent GB1328371 discloses, for example, a method for producing wire turbulators. The method provides to prearrange at least one wire twisted in spiral and subsequently to place a first wire inside the spiral. The method further provides to place a second wire externally to the spiral and then reciprocally twist the first and the second wire, so that the loops distribute according to a helical path. Patent DE 1477008 shows a further example of a method for manufacturing wire turbulators. In particular, the method provides to lead an elongated shape material through a load device mobile along a working direction.

Particularly in the technical field of the heat-exchanger devices, it is needed to devise a method for manufacturing turbulator members starting from wire or band, which allows to automate the production thereof.

It is as well needed to develop apparatuses that permit to optimize the production process of the turbulator members, improving productiveness.

Disclosure

The task of the present invention is that of solving the aforementioned problems, devising a method and an apparatus for manufacturing turbulator members for use in heat- exchanger and similar devices, which is able to manufacture in an optimal way turbulator members starting from elongated shape material, in particular wire or band.

Within such task, it is a further scope of the present invention to provide a method that allows to lessen the production time of the turbulator members.

A further scope is to provide a versatile apparatus, which can be configured to produce turbulator members with a wide range of shapes and size.

Another scope of the invention is to provide an apparatus having high productiveness. A further scope of the invention is to provide an apparatus for manufacturing turbulator members of simple constructive and functional conception, having surely reliable functioning, versatile use as well as relatively economic cost.

The cited scoped are reached, according to the present invention, by the method and by the apparatus for manufacturing turbulator members starting from material having elongated shape, for example wire or band, according to claims 1 and 10.

In substance, the method reaches such scopes providing to feed a portion of an elongated shape material, preferably having the shape of wire or band, having a determined extension, to a working bench at which a first twisting head and a second twisting head work along an axial working direction, being placed facing and coaxial according to a longitudinal axis. The above mentioned portion of material having elongated shape is unwound by feed means associated with the working bench, and straightened along the working direction through a load device, mobile along the above mentioned working direction, between the first twisting head and the second twisting head.

The load device advantageously carries unwinding means, predisposed for example to place the wire material to be unwound in a U- conformation.

According to the method, the unwound and fed portion is clamped at its opposite ends at the first winding head, through first clamping means carried by the first head itself, and at the second twisting head, through respective second clamping means, carried by the second twisting head.

The method according to the invention provides then to operate the first twisting head in relative rotation, about the above mentioned longitudinal axis, with respect to the second twisting head, for a predetermined number of loops, in order to manufacture the desired turbulator member.

According to the invention, before operating the above mentioned relative rotation, the portion of elongated shape material, for example in wire or band, straightened along the working direction and clamped at its opposite ends is preferably submitted to traction through compensation means associated with the second twisting head.

According to a particular aspect of the invention, the first twisting head is preferably operated in rotation by means of a motor member connected therewith, preferably through the interposition of transmission means, while the second twisting head is prevented to rotate in the same direction.

According to a further aspect of the invention, the second twisting head is operated in rotation according to a direction opposite to the rotation of the first twisting head, so as to accelerate the production cycle for the manufacturing of the turbulator member.

Preferably, the first twisting head is fixed in axial direction, while the second twisting head is mobile along the above mentioned working direction, to allow the positioning and the straightening of the material to be twisted in helical manner.

According to a particular aspect of the invention, the method firstly provides to prearrange along the working axial direction, between the first twisting head and the second twisting head, at least one filiform auxiliary element, having helical shape, and to feed a first portion of filiform material. The first portion of filiform material is then inserted inside the above mentioned prearranged helical auxiliary element, and subsequently fed and straightened as it was previously described, to constitute the core element of the turbulator member to be manufactured, between the first twisting head and the second twisting head.

Then, the method provides to operate in a back stroke the load device along the above mentioned working direction, so as to unwind a second portion of filiform material, for example from the second twisting head until the first twisting head, passing externally to the predisposed helical auxiliary element. In practice, the couple of portions, fed as described above, arranges itself in U-shape, with the first fed portion arranged inside the helical element and the second fed portion arranged externally to the helical auxiliary element. The U- shaped filiform material constitutes the central core of the turbulator element being manufactured. The method provides then to clamp the above mentioned U-shaped filiform material at its opposite ends by means of the first clamping means of the first twisting head and of the second clamping means of the second twisting head, respectively.

Such steps precede the previously described step of relative rotation of the first twisting head and of the second twisting head, further to which the interlacing of the U-shaped wire material, or central core, is carried out with the helical auxiliary element inserted therein.

As an alternative, it is possible to provide that the feed of the cited filiform material is performed in a different way. In fact, it is possible to provide that the first portion of the above mentioned filiform material is clamped at one free end by the first clamping means of the first twisting head, inserted inside the helical auxiliary element, wound in U- configuration about the unwinding means carried by the cited load device, and unwound, conveyed, by the feed means associated with the working bench, so as to arrange a second portion, parallel to the cited first clamped portion of filiform material. As a consequence, the fed filiform material progressively arranges itself in U-shape further to the advancing, in the above mentioned working direction, of the cited load device. Further to the feeding in the above mentioned working direction, between the first twisting head and the second twisting head, the cited filiform material is then progressively fed in U- shape between the first twisting head and the second twisting head. The filiform material is then clamped through the second clamping means at the second twisting head, at a respective curved portion of the U-shape and locked to the opposite end of the second portion of the same U-shape to the first twisting head. The method provides then to operate the above mentioned relative rotation, between the first twisting head and the second twisting head, as it was previously described, to obtain the interlacing of the wire material arranged in U shape, or central core, with the helical auxiliary element inserted therein.

According to a particular aspect of the invention, it is possible to provide that a second filiform auxiliary element is provided and inserted about the second tract of the U shape made up of the fed filiform material.

According to a particular aspect of the invention it is advantageous to provide to block opposite ends of the provided helical auxiliary element, at the first clamping means of the first twisting head and of the load device, so as to obtain the progressive straightening of the same helical auxiliary element, further to the handling of the load device in the feeding working direction, towards the second twisting head. In the same way, it is possible to provide to lock the second helical auxiliary element, if provided. The apparatus for manufacturing turbulator members according to the invention hence comprises a working bench, on which a first twisting head and a second twisting head are arranged facing and coaxial with respect to a longitudinal axis.

The first twisting head, preferably fixed, carries first clamping means, to hold a part, preferably an end part, of a portion of the elongated shape material, in wire or band, used for manufacturing a tubular member. Such wire or band material, unwinding from feed means, is guided by a load device, mobile between the first twisting head and the second twisting head.

The load device carries auxiliary unwinding means, configured to arrange about themselves the elongated shape material, in a U-configuration.

According to the invention, the first twisting head can be operated in rotation about the above mentioned longitudinal axis.

The second twisting head, mobile relatively to the first twisting head along the above mentioned longitudinal axis, carries second clamping means, to clamp an opposite part of the above mentioned portion of wire or band material, fed in straightened configuration by means of the load device along a working direction, parallel to the above mentioned longitudinal axis.

The second twisting head is prevented to rotate at least in the rotation direction of the first twisting head.

According to an aspect of the invention, it is possible to provide that the second twisting head is operated in rotation according to the direction opposite to the rotation of the second twisting head, to cooperate to the twisting of the portion of material clamped between the first twisting head and the second twisting head.

According to a particular aspect of the invention a compensation device is associated with the second twisting head, to keep straightened the material being worked.

Preferably, the compensation device comprises a positioning carriage, predisposed to place the second twisting head along the working direction, in a position spaced in determined manner from the first twisting head, to receive in straightened conformation the portion of elongated shape material. Return or traction means, preferably of elastic type, are connected, preferably interposed between the positioning carriage and the second twisting head, to keep straightened, that is under a determined tension, the portion of elongated shape material being worked.

It is possible to associate with the apparatus according to the invention a dedicated apparatus, predisposed to manufacture a helical element, manufactured starting from filiform material, destined to constitute, along with a central element twisted according to a longitudinal axis, for example through the above mentioned apparatus, wire turbulator members, in particular for use in heat-exchanger devices in which the heat-exchange carrier is in the liquid state.

The dedicated apparatus comprises a first working head and a second working head, facing and coaxial according to a longitudinal axis, arranged on a working bench. The first working head and the second working head can be operated synchronically in rotation about the above mentioned longitudinal axis, through command means, for example associated only with the first working head. The first working head is preferably a drive one, and the second working head is driven by the first working head, in the above mentioned rotation motion.

The first working head and the second working head respectively carry first clamping means and second clamping means to clamp a support element at its opposite ends. The dedicated apparatus further comprises a positioning device, for example a mobile carriage, predisposed to receive the unwinding filiform material and to bring it in a direction substantially parallel to the above mentioned longitudinal axis, in suitable step relationship with the rotation of the first head and of the second head.

In substance, the method for manufacturing said filiform helical element provides to block the support element respectively to the first working head and to the second working head, to unwind the filiform material through the positioning device and to fix a free end of the filiform material to the same support element.

The method provides then to operate the synchronous rotation of the first working head and of the second working head, in suitable step relationship with the advancing of the positioning device in axial direction, to carry out the twisting of the same filiform material about the central element according to a determined pitch and according to a determined relation between rotation speed of the heads and axial advancing.

The method and the apparatus for manufacturing turbulators allow to manufacture, in an optimal way, turbulator members of different type, starting from either wire or band.

The method for manufacturing turbulator members allows to reduce the production time of such devices, increasing the productiveness and thus the efficiency of the productive process.

The apparatus which carries out such method according to the present invention can be configured in a very variable way so as to satisfy the specific exigencies of the user.

A feature of the present invention is the ability to set the rotation speed of the concerned rotating members, according to the characteristics of the turbulator member to be manufactured. Moreover, the rotating units can be placed at a mutual distance, variable and adjustable according to any length of the material in wire or band.

In addition, it is possible to manufacture turbulator members of any shape, for example using a support element of any shape to create the helical element. It is possible as well to insert one or more helical elements between the twisting heads to manufacture turbulator members in wire of any shape and of different structural complexity.

The apparatus according to the invention is able to work with material of reduced thickness and/or of difficult manipulation, such as for example annealed materials, generally difficult to manipulate in particular in case of great twisting length, as it is the case of the manufacturing of turbulator members.

Description of Drawings

Particulars of the invention shall be more apparent from the detailed description of a preferred embodiment of the apparatus for manufacturing turbulator members for use in heat-exchanger devices according to the invention, illustrated for indicative purposes in the attached drawings, wherein:

figure 1 shows a schematic side view of the apparatus for manufacturing turbulator members according to the present invention;

figure 2 shows a schematic lateral view of a dedicated apparatus, which can be associated with the apparatus shown in figure 1 according to the invention;

figures 3, 4 and 5 show schematic top views of the apparatus shown in figure 1 in subsequent working steps.

Best Mode

With particular reference to such figures, the apparatus for manufacturing turbulator members starting from elongated shape material 100, in wire or band, according to the present invention has been indicated in its entirety with 1 .

The apparatus 1 comprises a feed device 2 of the material 100, for example made up of unwinding means, as well as conveying means 23, predisposed to carry out the unwinding of the same material 100 from a roll or from a coil.

Downstream of the feed device 2, the apparatus 1 comprises a load device 3, predisposed to receive the material 100 in wire or band from the same feed device 2 (see figure 1 ) to suitably load the same apparatus 1 .

The load apparatus 3 preferably shapes a load carriage mobile along a working direction A on a working bench. The load carriage 3 is suitably operated according to a shift motion, on guide rails 4 fixed to the support framework 5 of the apparatus 1 . The rails 4 arranged on the working bench are preferably substantially horizontal.

The load device 3 preferably carries auxiliary unwinding means 24, preferably of the type of a convey wheel, about which the material 100 can unwind to arrange itself in a U- configuration, as it is described in detail in the following.

The apparatus 1 comprises as well a first twisting unit 10 arranged at one end 4a of the guide rails 4. The first twisting unit 10 comprises a first twisting head 1 1 , preferably fixed with respect to the working direction A and frontally carrying clamping means 12, to clamp or tightly hold a portion, preferably an end portion, of the wire or band material 100.

The first twisting head 1 1 can be operated in rotation about a longitudinal axis A1 , parallel to the above mentioned working direction A, through a motor member 13 connected with it, preferably through the interposition of suitable transmission means.

The apparatus further comprises a second twisting unit 20, opposed and coaxial to the first twisting unit 10.

The mobile twisting unit 20 comprises a second twisting head 21 predisposed to hold, by means of further clamping means 22, frontally carried, the opposed end or portion of the material 100, in wire or band, fed by the carriage 3 along the working direction A.

The clamping means 12, 22 of the respective heads 1 1 , 21 can be, for example, of the pliers or jaw type, or of different type suitable to tightly hold one or more portions of material 100, for example one or both the free ends of the unwound portion.

The second twisting head 21 is preferably prevented to rotate about the longitudinal axis

A1 . As an alternative, the second twisting head 21 can be suitably operated in rotation by suitable actuator means, in a direction opposed with respect to the first twisting head 1 1 , to speed up the twisting cycle of the material on itself.

The first fixed twisting head 1 1 and the second mobile twisting head 21 are mobile relatively to one another in the working direction A, to be mutually placed at a distance adjustable according to the extension of the portion of material 100 to be interposed and clamped between them.

The apparatus comprises as well a compensation device 30, predisposed to straighten, as required, the unwound portion of material 100.

Such compensation device 30, preferably associated with the second twisting head 21 , comprises a positioning carriage 31 , predisposed to draw the above mentioned associated head 21 , allowing to vary the axial position along the working direction A according to the length of the portion of elongated shape material 100 to be treated.

The compensation device 30 preferably comprises return or traction means 32, for example spring means, interposed between the positioning carriage 31 and the head 21 associated therewith, able to exert, in use, a controlled traction on the portion of material in wire or band 100 fixed respectively to the first twisting head 1 1 and to the second twisting head 21 through respective clamping means 12, 22.

Advantageously, it is possible to associate with the disclosed apparatus 1 a dedicated apparatus 1' for manufacturing helical elements in wire, starting from filiform shape material 100. Such dedicated apparatus V similarly comprises a first working head 11 ', a second working head 21 ', cooperating, facing and coaxial one another according to a longitudinal axis B1 , and a guide device 6 of filiform material 100, mobile along a working direction B, preferably parallel to the above mentioned longitudinal axis B1 , through a respective actuator member.

The first working head 1 1' can be operated in rotation about the longitudinal axis B1 , while the second working head 21' is idle to the rotation according to the same longitudinal axis B1 , or can be operated in synchronic way in rotation in the same direction.

The first working head 11 ' and the second working head 21' frontally carry first clamping means 12' and second clamping means 22', respectively, to clamp a support element 8, cooperating for the manufacturing of the above mentioned helical element.

The guide device 6 preferably shapes a carriage mobile on guide rails 7 fixed to the support framework 5' (see figure 2), predisposed to receive the unwinding filiform material 100, in order to guide it in the working direction B. More precisely, the carriage 6 is predisposed to guide the feed of the filiform material 100 unwinding from a respective feed device 2', for example an unwinder device in case the material is firstly wound on a coil, to allow the correct winding of the filiform material 100 about the above mentioned support element 8.

Therefore, during the working steps of the dedicated apparatus 1', the support element 8 is held at one end by the clamping means 12' of the first working head 11 ' and at the opposite end by the clamping means 22' of the second working head 21 '. Such support element 8 can have different shapes according to the exigencies; for example, it can have circular, rectangular, pentagonal or polyhedral cross-section.

The functioning of the apparatus for manufacturing turbulator members starting from elongated shape material, in particular wire or band, is described in the following.

Firstly, the first twisting head 1 1 and the second twisting head 21 are arranged on the working plane or working bench suitably spaced, so as to receive a portion of material 100 of determined extension. For example the second twisting head 21 is suitably shifted with respect to the first twisting head 1 1 , preferably through the activation of the positioning carriage 31 of the compensation device 30.

Subsequently, the material 100 in wire or band, unwinding from the feed device 2, is fed. A portion of the material 100 is intercepted and guided by the load carriage 3 to be fed and drawn along the working direction A on the working bench. The load carriage 3 is therefore operated in a shift motion along the working direction A, sliding along the rails 4. The elongated shape material 100 is then unwound from the load carriage 3, for example starting from the first fixed twisting head 1 1 until the second mobile twisting head 21 or vice versa. When a portion of the material having elongated shape 100 of determined extension is straightened upon the working bench and oriented along the working direction A, respective opposite portions, for example free ends suitably separated from the rest of the unwinding material 100, are clamped at the twisting units 10, 20 through the activation of the first clamping means 12 of the first twisting head 1 1 and of the second clamping means 22 of the second twisting head 21 .

In such step, the return or traction means 32 are preferably activated, associated with the compensation device 30 to correctly place the second head 21 and to submit the so clamped portion of material 100 to traction. Such compensation is particularly advantageous since, further to the subsequent twisting, the portion of material 100 is submitted to a progressive reduction of length, compensated, indeed, by the compensation device 30, which keeps correctly straightened the material 100 and at the same time ensures a constant traction.

Subsequently, the first twisting head 1 1 is operated in relative rotation, according to the longitudinal axis A1 along which the portion of material 100 is straightened and clamped, with respect to the second twisting head 21 through the motor member 1 3 so as to twist in corresponding way the portion of material 100 in wire or band.

In case the second twisting head 21 is motorized, it is possible to operate in rotation such twisting head in opposite direction with respect to the rotation direction of the first twisting head 1 1 , so as to speed up the twisting step.

The rotation of the first twisting head 1 1 is stopped after having reached a predetermined number of loops, suitable to create the desired turbulator member.

Finally, the twisted portion of material 100 is extracted.

It is to be observed that, in case of wire material, the method provides, further to the clamping of one end of the wire by the first twisting head 1 1 or before such clamping, to insert about it an auxiliary helical element, preferably made of the same wire material through the dedicated apparatus V previously described.

Then, the opposite portion of wire 100 is clamped at the second twisting head 21 , guided by the carriage 3, and, then, the load carriage 3 is operated in a back stroke, to arrange the wire material 100 in U shape, to lock it between the first twisting head 1 1 and the second twisting head 21 . In practice the free ends of the U folded portion of wire 100 are locked to one head while the folded portion to the other twisting head.

The relative rotation between the first twisting head 1 1 and the second twisting head 21 , as it was previously described, produces the interlacing of the material 100 folded in U- shape about the above mentioned spiral element, to manufacture in particular a wire turbulator member. As an alternative, it is possible to provide that the feeding of the material 100, in particular filiform, takes place in a different way, for the manufacturing of wire turbulator member with a helical auxiliary element 1 10 wound about it.

In fact, it is possible to provide that a first portion 101 of the filiform material 100 is locked at a free end to the first clamping means 12 of the first twisting head 1 1 , inserted inside the helical auxiliary element 1 10, wound in U-shape about auxiliary unwinding means 24 of the load device 3 and unwound by unwinding means 23 of the feed means 2 associated with the working bench, so as to arrange a second portion 102, parallel to the first portion 101 of filiform material 100, thus straightening in the U-shape after the feeding in the working direction A of the load device 3. After the forward stroke in the working direction A, between the first twisting head 1 1 and the second twisting head 21 , the filiform material 100 is progressively fed in U-shape straightened between the first twisting head 1 1 and the second twisting head 21 .

The filiform material 100 is then clamped by the second clamping means 22 at the second twisting head 21 , at a respective curved portion 103 of the U-shape, and clamped at the opposite end of the second portion of the U-shape by the first twisting head 1 1 .

The method then provides to operate the aforesaid relative rotation, between the first twisting head 1 1 and the second twisting head 21 , as described above, to obtain the interlacing of the wire material 100 disposed in the U-shape, or central core, with the helical auxiliary element 1 10 inserted therein.

It is also possible that a second filiform auxiliary element 120 is prepared and inserted around the second portion 102 of the U-shape preferably made of the filiform fed material 100.

It is also advantageous to lock opposite ends of each helical auxiliary element 1 10, 120, at the clamping means 12 of the first twisting head 1 1 and at auxiliary clamping means 25 of the load device 3, so as to perform the progressive straightening of the same auxiliary helical element 1 10, 120 after the handling of the load device 3 in the working feed direction A, towards the second twisting head 21 .

To produce such helical element through the dedicated apparatus 1', which can be associated with the apparatus 1 , to produce wire turbulator members, the first working head 11 ' and the second working head 21' are arranged at a suitable reciprocal distance, suitable to receive the support element 8.

Then the support element 8 is arranged along the longitudinal axis B1 and its opposite ends are locked at the first working head 1 1' and at the second working head 21', on the respective clamping means 12', 22'.

Then the wire material 100 is associated with the guide carriage 6, so as to allow its unwinding from the feed device 2'. [99] A free end of the wire 100 is fixed to the support element 8, clamped between the first working head 1 1' and the second working head 21'.

[100] The first working head 11' and the second working head 21' are then operated in rotation, in synchronic manner, upon command of the motor member 13' so as to produce the twisting of the material in wire 100 about the support element 8. At the same time and in suitable step relationship, the guide carriage 6 is operated in motion along a longitudinal direction B so as to obtain a predetermined displacement of the guide carriage 6 for every loop of the support element 8.

[101 ] The above mentioned rotation is stopped at the completion of a predetermined number of loops, suitable to manufacture the desired helical element.

[102] Finally, the wire material wound in spiral about the support element 8 is extracted, thus obtaining a helical element destined to contribute to the manufacturing of the wire turbulator members, as it was previously described.

[103] The apparatus described by way of example is susceptible of numerous modifications and variations according to the different exigencies.

[104] In practice, the embodiment of the invention, the materials used, as well as the shape and dimensions, may vary depending on the requirements.

[105] Should the technical characteristics mentioned in each claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.