TUBULAR DEVICE FOR THE TRANSIT OF A HEAT EXCHANGE FLUID, PARTICULARLY FOR HEAT EXCHANGERS

Abstract

 Tubular device (10) for the transit of a heat exchange fluid, particularly for heat exchangers, which comprises a tube (11) that has consecutive portions (11a, 11b, 11c, 11d, 11e, 11f) that have a cross-section with a profile defined by a plurality of lobes (12, 13, 14, 15) arranged in a substantially radial direction, and comprises a rod-like element of polygonal cross-section (16), a flow diverter, extractable, which is inserted into the axial space of the tube (11) and is designed to divert the flow of heat exchange fluid introduced into the tube (11) toward the heat exchange channels (20, 21, 22, 23, 24, 25, 26, 27) of that tube, which have a lobe-like cross-section.

Description

[0001] The present invention relates to a tubular device for the transit of a heat exchange fluid, particularly for heat exchangers.

[0002] Today liquid/gas heat exchangers, particularly for boilers, are known and widespread which have excellent performance and with which installers are very satisfied, and which comprise a chamber for the passage of a first heat exchange fluid, passed through by conduits for the passage of a second heat exchange fluid, the peculiarity of which consists in that at least part of these conduits are provided by a plurality of tubes, each one of which has a cross-section with a profile defined by a plurality of lobes arranged in a substantially radial direction.

[0003] The particular shape of such tubes makes it possible to considerably increase the turbulence of the gas that has to pass through them, with respect to tubes of circular or lenticular cross-section.

[0004] That notwithstanding, such tubes with lobe-shaped cross-section show room for improvement.

[0005] In fact, no matter how proximate the connection regions between two successive lobes of a tube are to the axis of the tube, a channel always remains in the neighborhood of such axis, from which the hot gas escapes without having optimally struck the internal surfaces of the channels with lobe-shaped cross-section of the tube, and having substantially yielded very little of the heat possessed.

[0006] Furthermore, such conventional tubes, precisely because they have a cross-section that is very narrow centrally, are difficult to clean and relatively inclined to clogging.

[0007] In order to overcome these drawbacks, a tubular device has been developed, and is the subject matter of Italian patent no. 1393847 in the name of S.A.R.I. Stampi Industriali di Zen Bortolo, with priority date of 31/03/2009. Such tubular device, for the transit of a heat exchange fluid, particularly for heat exchangers, comprises a tube that has at least one portion that has a cross-section with a profile defined by a plurality of lobes arranged in a substantially radial direction, characterized in that it comprises a rod-like element, a flow diverter, extractable, which is inserted into the axial space between the connecting portions between two successive lobes, and is designed to laterally divert the flow of heat exchange fluid introduced into the tube, toward the heat exchange channels of the tube, which have a lobe-like cross-section.

[0008] A gas that passes through such a tubular device is given a turbulence that improves the heat exchange with respect to what can be achieved with the previously-mentioned conventional tubes.

[0009] Moreover, by virtue of the presence of the extractable rod-like element, a tubular device is devised that is easy to clean, it being sufficient to extract the rod-like element in order to have sufficient space inside the tube to maneuver a cleaning instrument.

[0010] Such tubular device, although efficient, has some aspects that are susceptible of improvement.

[0011] In fact, in such tubular device, portions with three radial lobes alternate and are angularly offset with respect to the longitudinal axis of the tubular device; however, such configuration still allows the formation of privileged escape channels for the gas passing through them, the heat of which is not optimally exchanged, with consequent waste of heat energy.

[0012] Further, such conventional tubular device is provided with a rod-like flow diverter which is constituted by a bar with a circular cross-section, i.e. a cylindrical bar.

[0013] The cylindrical surface of such bar however, while impeding the flow of gas from transiting through the central channel of the tube, does not result in any particular redirection or remixing of the transfer fluid.

[0014] The aim of the present invention is to provide a tubular device for the transit of a heat exchange fluid, particularly for heat exchangers, which is capable of overcoming the drawbacks exhibited by conventional tubes with lobe-shaped cross-section.

[0015] Within this aim, an object of the present invention is to provide a tubular device in which the gas that passes through it is given a turbulence that improves the heat exchange with respect to what can be achieved by the cited conventional tubes.

[0016] Another object of the present invention is to provide a tubular device that is easy to clean.

[0017] This aim and these and other objects which will become better evident hereinafter are achieved by a tubular device for the transit of a heat exchange fluid, particularly for heat exchangers, according to claim 1.

[0018] Further characteristics and advantages of the invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the tubular device according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

• Figure 1 is a perspective view of a tubular device according to the invention;
• Figure 2 is a cutaway perspective view of the device in Figure 1;
• Figure 3 is a side view of a portion of a tubular device according to the invention;
• Figure 4 is a cross-sectional view taken along the line IV-IV of Figure 3;
• Figure 5 is a cross-sectional view taken along the line V-V of Figure 3;
• Figure 6 is a cross-sectional view taken along the line VI-VI of Figure 3;
• Figure 7 is a cross-sectional view taken along the line VII-VII of Figure 3;
• Figure 8 is a cross-sectional view taken along the line VIII-VIII of Figure 3.

[0019] With reference to the figures, a tubular device for the transit of a heat exchange fluid, particularly for heat exchangers, according to the invention, is generally designated with the reference numeral 10.

[0020] The tubular device 10 comprises a tube 11 that has consecutive portions, for example designated with the reference numerals 11a, 11b, 11c, 11d in Figures 1 and 2, that have a cross-section with a profile defined by a plurality of lobes, for example the lobes 12, 13 of the portion 11b in Figure 2 and in Figure 4, and the lobes 14, 15 in Figure 6, which are arranged in a substantially radial direction.

[0021] Such tubular device 10 also comprises a rod-like element of polygonal cross-section 16, a flow diverter, extractable, which is inserted into the axial space of the tube 11 and is designed to divert the flow of heat exchange fluid introduced into the tube 11 toward the heat exchange channels, designated with 20, 21, 22, 23, 24, 25, 26, 27 in Figures 4 to 6, of that tube, which have a lobe-like cross-section.

[0022] In particular, the rod-like element 16 is constituted by a bar with a square cross-section.

[0023] The rod-like flow diverter 16 is provided with a contoured end 23, clearly visible in Figure 1, for gripping for the extraction of the rod-like element 16 from the tube 11, in order for the tube 11 to be cleaned.

[0024] The tube 11 has portions 11a, 11b, 11c and 11d, each one of which has a cross-section with a profile defined by two lobes, 12 and 13 for the cross-section in Figure 4 and two lobes 14 and 15 for the cross-section in Figure 6, which are arranged in a substantially radial direction, and mutually opposite with respect to each other.

[0025] The portions 11a, 11b, 11c, 11d, but also 11e and 11 f in Figure 3, are made so that the cross-sections of two subsequent portions of tube 11a, 11b, 11c, 1d, 11e, 11f are rotated with respect to the axis of the tube 11 by a certain angle, for example 90° as shown by Figures 4 and 6, Figure 4 showing a first portion 11e, and Figure 6 showing a second portion 11f.

[0026] The portions with lobe-shaped cross-section 11a, 11b, 11c, 11d, 11e, 11f have a cross-section shaped like two mutually opposite lobes 12 and 13 as in Figure 4, and 14 and 15 rotated through 90° with respect to the axis, as in Figure 6; each lobe-shaped section is connected to the opposite lobe-shaped cross-section by way of two inward-curving portions 34 and 35 in Figure 4 and 36 and 37 in Figure 6, which are defined by an operation to squeeze the tube 11.

[0027] The cross-section of the rod-like flow diverter 16 has dimensions that are such as to correspond to the minimum distance between the mutually opposite inward-curving portions 34, 35 and 36, 37; in this manner the rod-like flow diverter 16 reduces the axial passage of heat exchange fluids to the minimum.

[0028] The tube 11 has intermediate portions, for example 30, 31 and 32 in the figures, between the portions with lobe-shaped cross-section 11a, 11b, 11c, 11d, 11e, 11f, the cross-section of which, clearly visible in Figure 5, comprises the inward-curving portions of two contiguous portions with lobe-shaped cross-section.

[0029] The intermediate portions 30, 31 and 32 therefore have four inward-curving portions 40, 41, 42 and 43 which are connected by corresponding radially-extending folds, each one defining a heat exchange channel 22, 23, 24 and 25 with a narrowed cross-section with respect to the channels 20, 21 and 26, 27 defined at the lobes.

[0030] It should be understood that, in alternative embodiments, there can also be a different number of lobes.

[0031] The tube 11 has substantially cylindrical end portions 40 and 41, and therefore they are relatively easy to butt-weld.

[0032] Figure 7 shows a cross-section of a first end 40.

[0033] The tube 11 can easily be obtained by way of processing of a metallic tube by squeezing.

[0034] In practice it has been found that the invention fully achieves the intended aim and objects.

[0035] In particular, with the invention a tubular device has been devised in which the gas that passes through it is given, by virtue of the rod-like element with a square cross-section, a turbulence that improves the heat exchange with respect to what can be achieved by the cited conventional tubes.

[0036] Furthermore, thanks to the presence of the extractable rod-like element 16, a tubular device has been devised that is easy to clean, it being sufficient to extract the rod-like element 16 in order to have sufficient space inside the tube 11 to maneuver a cleaning instrument.

[0037] The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

[0038] In practice the components and the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

[0039] The disclosures in Italian Utility Model Application No. 202016000078044 (UA2016U159938) from which this application claims priority are incorporated herein by reference.

[0040] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A tubular device (10) for the transit of a heat exchange fluid, particularly for heat exchangers, characterized in that it comprises a tube (11) that has consecutive portions (11a, 11b, 11c, 11d, 11e, 11f) that have a cross-section with a profile defined by a plurality of lobes (12, 13, 14, 15) arranged in a substantially radial direction, and comprises a rod-like element of polygonal cross-section (16), a flow diverter, extractable, which is inserted into the axial space of the tube (11) and is designed to divert the flow of heat exchange fluid introduced into said tube (11) toward the heat exchange channels (20, 21, 22, 23, 24, 25, 26, 27) of said tube, which have a lobe-like cross-section.

2. The tubular device according to claim 1, characterized in that said rod-like element (16) is constituted by a bar with a square cross-section.

3. The tubular device according to one or more of the preceding claims, characterized in that said rod-like flow diverter (16) has a contoured end (23), for gripping, for the extraction of the rod-like element (16) from said tube (11).

4. The tubular device according to one or more of the preceding claims, characterized in that said tube (11) has portions (11a, 11b, 11c, 11d, 11e, 11f) each one of which has a cross-section with a profile defined by two lobes, (12, 13, 14, 15) arranged in a substantially radial direction, and mutually opposite with respect to each other.

5. The tubular device according to one or more of the preceding claims, characterized in that said portions (11a, 11b, 11c, 11d, 11e, 11f) are made so that the cross-sections of two subsequent portions of tube (11a, 11b, 11c, 1d, 11e, 11f) are rotated at an angle of 90° with respect to the axis of the tube (11).

6. The tubular device according to one or more of the preceding claims, characterized in that each lobe-shaped section is connected to the opposite lobe-shaped section by way of two inward-curving portions (34, 35, 36, 37).

7. The tubular device according to one or more of the preceding claims, characterized in that the cross-section of the rod-like flow diverter (16) has dimensions that correspond to the minimum distance between the mutually opposite inward-curving portions (34, 35, 36, 37).

8. The tubular device according to one or more of the preceding claims, characterized in that said tube (11) has intermediate portions (30, 31, 32) between the portions with lobe-shaped cross-section (11a, 11b, 11c, 11d, 11e, 11f), the cross-section of which comprises the inward-curving portions of two contiguous portions with lobe-shaped cross-section.

9. The tubular device according to one or more of the preceding claims, characterized in that said intermediate portions (30, 31, 32) have four inward-curving portions (40, 41, 42, 43) which are connected by corresponding radially-extending folds, each one defining a heat exchange channel (22, 23, 24, 25) with a narrowed cross-section with respect to the channels (20, 21, 26, 27) defined at the lobes.

10. The tubular device according to one or more of the preceding claims, characterized in that said tube (11) has substantially cylindrical end portions (40, 41).

Drawing