DE2422340A1 - PATTERNED TUBES AND METHODS FOR MAKING THEM FROM METAL STRIP - Google Patents

Description

Dr.-Inn. Kr ψ Rl'SZHXli
Dipl.-lr.g. CLAF RUSGHKE
Dip: .-! R: ₂ .H / N \ ^ E. RUSCHKE e

s γ. ^ γχ; κεν so ° 'Ma / 1974

Pienzenajerstraße 2

Olin Corporation, New Haven, Connecticut V.St.A.

Patterned tubes and methods of making them from metal strip.

The present invention relates to patterned ones Pipes and their production, preferably in flow production, from metal strip as the starting material.

For example, a metal strip of a predetermined width and any length and with side edges is continuously moved forward through a tube rolling mill in order to bend the strip into a tube, the side edges of which abut one another and form a longitudinal seam. The seam is continuously closed by welding or in some other suitable manner to produce a liquid-impermeable endless tube.

The present invention relates in one of its embodiments Process for tube manufacture with continuous

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Embossing on one or more surfaces of the strip before it enters the rolling mill according to one desired pattern so that the finished pipe has an embossed surface on the inside or outside or on both sides of the pipe wall as desired. The pattern can be in accordance with the Purpose for which the pipe is intended to be selected.

The present invention also relates to the continuous physical deformation of the strip prior to its entry into the tubular rolling mill by producing longitudinal, spiral or transverse strip formations, Grooves or grooves in the belt. In this way, what is finally made from the deformed ribbon has Pipe a wall structure that is physically designed in one fora or another as opposed to a pipe wall structure developed from the embossed tape. Again, the choice is made by band deformation generated pattern is determined by the intended use of the pipe.

Accordingly, the present invention relates to pipes » which are made from a band that has been given a pattern as a result of embossing, etching or the like Surface treatment, or it concerns pipes that are made from

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a band are made, which is provided with a pattern due to corrugation, wave-shaped design or other metal forming processes.

Another object of the present invention is to provide a pattern in the surface treatment of the tape one or both sides of the tape so that the wall of the finished pipe creates a pattern on the inner wall surface or the outer panel, or both panels, as desired, and that the pattern can easily be changed.

If the pattern is created by deforming the ribbon, it will understandably appear on both the Inside as well as on the outside of the pipe.

For the purpose of describing the present invention, the surface treatments are on or on multiple sides of the tape or the deformation of the tape, which distinguishable surface features or create wall deformations on the pipe, referred to as a "shaped pattern", "pattern shape" or "pattern".

The process of developing patterns by surface treatment or by deformation of the

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Band can be chosen at will and have no decisive influence on the fundamentals of the present invention.

Therefore, the term "pattern", "shaped pattern", or "pattern shape" applied to the metal strip include any method or mode of operation that removes metal from any surface of the tape or the tape .physically deformed before it enters the tubular rolling mill.

The term "pattern" therefore denotes the result of such metal removal or metal deformation .

The main object of the present invention is to provide a method for producing separate Lengths of pipes having wall sections or compartments which have shaped patterns, the Patterns are preferably interrupted by wall sections that are smooth or free of the shaped ones Patterns, and it is also the task to design the patterned pipes obtained in this way create.

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There is an additional object of the present invention dain to provide an improved process for the continuous manufacture of tubes from metal strip, in which separate lengths of tubes are created, preferably with discontinuous patterns in different ones Combinations and interchanges, whereby the interruptions e.g. due to intervening, adjacent pipe sections are created that are smooth or free of patterns.

Another object of the invention is to provide improved, patterned tubes as well as an improved, continuous Process for the production of pipes from metal strip, the pipe produced has a wall provided with a pattern, which is preferably interrupted by adjacent wall sections will, which are smooth or are free of shaped patterns, to divide the pipe into separate lengths depending on the choice to be separated in the area of a pattern or in the area of a smooth section.

A method that incorporates certain principles of the present invention can include the following method steps contain:

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Establishing a metal strip of a predetermined width, any length and with side edges; continuous Forward movement of the belt; continuous pattern formation on at least one surface of the belt during the Forward movement; intermittent interruption of the pattern-forming process step in order to ensure the continuous process interrupting the formed pattern and creating smooth sections in between, which give rise to the shape of an interrupted pattern; continuous deformation of the band into a tube Juxtaposing the side edges to form a seam; continuously closing the seam to create a liquid-impermeable seal, and then continuous cutting of the pipe into different lengths, the process step of cutting off

is made in those pipe areas that are characterized by smooth sections.

The tube of the present invention is formed from tape and is characterized by having an in Has a longitudinally extending, welded seam, furthermore a given wall thickness and an inner surface which corresponds to one side of the strip material, and an outer surface corresponding to the opposite side of the strip material. After an execution

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Form of the invention is a heat exchange increasing pattern in only a part of the wall thickness of the pipe formed, embossed in at least one of the surfaces by embossing the corresponding side of the tape, thereby creating a Change in the heat exchange-increasing pattern can be created by embossing the tape is changed.

In another embodiment, the tube has longitudinal corrugations which essentially wrap around its entire circumference extend with the exception of the parts of the pipe wall which lie on both sides of the weld seam and are not corrugated and butt against each other in a straight line.

Further developments and advantages of the present invention will emerge from the following description in conjunction with the drawings. In these show:

Figures 1, 2 and 3 characteristic examples of individual Lengths of pipes with abutting smooth and patterned wall parts or wall sections;

FIGS. 4 and 5 show typical rolling mill rolls for producing the patterns on the strip surfaces;

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6 shows a typical pair of rollers for generating a pattern by deforming the belt;

7 shows a finished section of a pipe in which the pattern is interrupted by a smooth wall part will;

Fig. 8 shows a typical shape for forming the tube;

Figure 9 is a side view of a rolling mill arrangement for creating patterns on the strip in a continuous manner Execution;

Fig. 10 is a schematic representation of a typical operation for forming the tube, beginning with feeding the tape and ending with cutting or severing the tube;

Figures 11 and 12 show the places where the pipe in individual parts can be separated or cut.

In Fig. 1, reference numeral 10 denotes a finite one Length of tube with smooth ends 11 and 12 and pattern section 13 in between. The inner surface 14 of the tube is completely smooth in this case.

2 shows a length of a pipe 15 with a smooth outer surface 16 over the entire length and with an inner, patterned surface 17 which is delimited by smooth end sections 18 and V.

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Fig. 3 shows another variation, in-tiem the pipe provided with a pattern 21 on the entire inner surface and the outer surface in area 22 smooth and on each As indicated by numerals 23 and 24.

Each of Figures 4 and 5 shows a pair of cooperating mill rolls 26, 27 and 28, 29 which ^{produce a pattern labeled 11} P "on one or both of the strip surfaces" S ".

Fig. 6 shows mill rolls 31, 32 which physically deform the strip "S" by creating stripes or Corrugations with the reference number 33.

From this it can be seen that the present invention is also applicable to the manufacture of a welded, hollow heat exchange tube with a weld seam lying in the longitudinal direction of the tube as shown in FIG. 1, 2 or 3, which is formed from a supplied metal strip. The pipe has a given wall thickness and an inner surface corresponding to one side of the belt and an outer surface corresponding to the opposite Side of the tape. The tube has a pattern which increases the heat exchange in at least

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one of the surfaces is embossed by embossing the opposite side of the tape in which the pattern extends the entire length of the tube or can preferably be interrupted, as shown. The pattern increasing the heat exchange can extend through only a portion of the pipe wall thickness, as illustrated in Figures 1 through 5, the variation in the pattern increasing the heat exchange as shown in FIG. 3 by varying the embossing of the tape can be achieved. Therefore, the heat exchange enhancing pattern on the outer surface and / or the inner surface of the pipe, or the pattern on the outer surface can be from Differentiate patterns on the inner surface, as shown e.g. in Fig. 3 with a diamond-shaped notched Pattern on the inner surface and a longitudinal stripe pattern on the outer surface. Optionally can can easily be achieved that the pattern increasing the heat exchange has a longitudinal variation in of the type of pattern, for example by applying a diamond-shaped notched pattern to a first one Part of the outer or inner surface and a longitudinal striped pattern on a second part of this Area; or, for example, by varying the degree of increase in heat exchange through attachment a deeper impression on the flow path

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upstream side of the tube than the downstream side or by eliminating it entirely the downstream embossing and the maximum heat exchange efficiency achieved thereby on the upstream tube side where the greatest amount of heat exchange occurs while increasing the Heat exchange on the downstream side is reduced to reduce the flow resistance on the Reduce heat exchange fluid and thereby increase the overall efficiency.

In Fig. 7, a separate length of tube 34 is provided with a pattern 36-36, which is formed by an abutting it smooth section 37 is interrupted.

In FIG. 8, the band according to FIG. 6 is shown in the course of the tube deformation, with the end edges 38 and 39 abut one another and form a longitudinal seam 41.

In accordance with another embodiment of the present invention, the tube 34 can be provided with a Pattern 36-36 should be provided which extends in the longitudinal direction without interruption, e.g. without the one abutting it smooth section 37. This results in a patterned tube with continuously extending corrugations.

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The corrugations preferably have a pitch P of 1.27 mm to 12.7 mm and a height H of 0.63 mm to 6.3 mm. The pitch to height ratio should vary between about 1: 1 to about 3: 1 and the outermost length of the pipe should preferably be at least 50 times greater than the height H.

The pipe according to the present invention is thus formed from the strip into the welded pipe, preferably by means of high-frequency welding, and therefore contains a longitudinal weld seam. On both sides of the weld seam, a section of the pipe wall which is located in the same direction as the weld seam and on the circumference outside the same is kept free of corrugations. These circumferential, non-corrugated sections should have a collapsed width of less than about 20%, preferably less than 10 % of the circumference of the pipe wall, measured against a circle that just encloses the apexes of the corrugations on the outside of the pipe. Preferably, the sum of the widths of the non-corrugated parts is about 0.38 mm to about 2.54 cm, and in a further preferred manner about 1.52 mm to about 5.08 mm.

With particular reference to Figure 8, it is essential that the non-corrugated edges

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38 and 39 of the band interrupt the corrugated parts of the band essentially at the apex of a corrugation, and that further each of the non-corrugated end portions abuts in a straight line. These demands are of Significance because the two non-corrugated end parts 38 and 39, the tube-forming rollers and especially the Must touch seal rollers to maintain alignment of edge portions.

In Fig. 9, the letter "M" denotes a pattern-forming one Rolling mill with a series of pattern forming rolls 42, 43; 44, 46 and 47, 48 operating in chronological order be taken (in accordance with the length of the pattern to be made) in order to an operating position, which is indicated by the reference numeral 49, to move into an inoperative position, which is indicated by reference numeral 51. Through suitable control or programming of the operating and decommissioning of the various pairs of mill rolls can be a broken or Intermittent patterns can be produced on the tape in accordance with various desired compositions or changes.

For example, a break in the pattern can be created on the lower surface 52 of the belt and

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the top surface 53 remain smooth, or vice versa.

If one or the other surface is to remain completely smooth, it is obvious that a smooth roller should be used this area must be brought into working contact.

Furthermore, the pattern rolling mill ^M M ^{H can be operated} with suitable programming for the production of pattern interruptions on the upper and Uhterflache of the strip (inner and outer surface of the pipe), which are in phase (or offset) to each other, so that a special pipe section may be smooth (or patterned) on both surfaces in a specially selected section in the end result, or one pattern on one surface may be offset in relation to the pattern on the opposite surface. Thus, smooth and patterned lengths of tubing can be placed on the inner and outer surfaces of a given length of tubing in phase or offset as pattern considerations will dictate the ultimate use of the tubing.

For example, FIG. 3 shows a staggered pattern in that portion 22 is on the outer surface of the Tube 20 is smooth, while the inner surface 21

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completely, without any interruption with a pattern is provided. A similar structure is shown by window 50 in FIG. Of course one can In-phase patterns on both the inside and outside of the pipe can be used if so it is asked for.

It is often necessary to prepare the strip accordingly before it enters the rollers in order to achieve this Achieve a clean, even longitudinal seam to ensure. Characteristically this requires beveling, flattening or cutting off the side edges of the tape stock so as to be uniform Create cross-sectional design in the strip before it enters the rollers.

The method steps according to the present invention can be applied to any metal strip that is used for pattern formation is suitable to be applied; however, the invention is preferably applicable to metal strip Steel, stainless steel, aluminum, aluminum alloys, copper, copper alloys, nickel and nickel alloys.

While the primary use of the tubes made in accordance with the principles of the present invention is for use in heat exchangers, it is entirely within the scope of the invention ₍ the external decoration

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and the aesthetic appearance of the patterns of the finished tubes in applications other than heat exchangers to use.

It is assumed that a variety of pattern deviations can be devised as this reasoning from the heat engineering, construction and ornamentation can require without affecting the thought and scope the invention is abandoned.

- patent claims -

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Claims (27)

Claims _2ur “first”, metallic tubes, which are provided with patterns in and on the tube wall, from a metal strip supply, characterized by the process steps: moving the strip forward from the strip supply; Pattern formation on at least one strip surface during its forward movement. Deformation of the patterned strip into a tube by placing the side edges together to create a seam; and liquid-impermeable sealing of the seam. 2. The method according to claim 1, characterized in that that the seam is welded by means of high frequency welding. 3. The method according to claim 1, characterized in that different patterns on opposite sides of the tape are formed. - 18 - 409847/0945 4. The method according to claim 1, characterized in that a pattern change extending in the longitudinal direction is formed on the tape. 5. Process for the continuous production of metallic pipes, the patterns in or on the pipe wall have, from a metal supply of a predetermined width, any length and with side edges, marked by the process steps: the continuous forward movement of the belt; continuous Forming patterns on at least one surface of the tape as it advances; Intermittent interruption of the process step of pattern formation in order to ensure the continuous process of the pattern formed to interrupt and intermediate smooth sections on the surface and create a break in the pattern; continuous deformation of the band into a tube Juxtaposing the side edges to form a seam; continuous closing of the seam in order to create a liquid impervious seal; and then constant cutting of the pipe into separate lengths, whereby the process step of cutting takes place in the areas of the pipe, which have smooth sections. - 19 409847/0945 6. A method for pipe production according to claim 5, characterized in that the process step of Pipe cutting takes place in the area of the pattern formed. 7. A method for pipe production according to claim 5, characterized in that the process step for Patterns are formed on opposite surfaces of the tape. 8. A method for pipe production according to claim 5, characterized in that the process step for Formation of patterns on opposite surfaces of the belt takes place simultaneously and the Process step of the interruption so timed is that the pattern break on a surface is in phase with the corresponding break on the second face. 9. A method for pipe production according to claim 5, characterized characterized in that the step of forming patterns on opposing one another Areas of the belt takes place at the same time and the process step of the interruption is timed so is that the pattern interruption is offset on one surface compared to the corresponding - 20 409847/0945 the interruption on the second surface. 10. The method according to claim 5, characterized in that the temporally intermittent interruption of the process step which forms the pattern, and the resulting interruption of the continuous course of the pattern formed is achieved by changing from one pattern shape to another pattern shape. 11. A method for producing corrugated heat exchange tubes from a metal strip supply, characterized by the following process steps: Forming longitudinal furrows in the metal strip, with longitudinal edge parts of the strip remaining free from furrows, and these edge parts are the same length as the free edges of the strip and inward from each of the free longitudinal edges of the tape extend and have a width less than about 20 % of the width of the grooved tape; Deforming the corrugated tape into the shape of a tube with non-corrugated longitudinal edge portions of the tape which abut one another in a straight line, the non-corrugated portions interrupting the corrugated portions substantially at the apex of a corrugation; and welding the ends of the tape together to - 21 - 409847/0945 - 21 - 242234Q to form a liquid-impermeable and pressure-resistant pipe. 12. The method according to claim 11, characterized in that the tape ends are welded together by high frequency welding are. 13. Welded, hollow metal heat exchange tube made of metal strip material, characterized in that that it has a weld seam in the longitudinal direction, the pipe has a given wall thickness, and has an inner surface that corresponds to one side of the strip material and an outer surface that corresponds to corresponds to the opposite side of the strip material, furthermore one which increases the heat exchange Pattern extends only part of the thickness of the pipe wall and is embossed in at least one of the surfaces is by embossing the corresponding side of the tape, with a variation in the heat exchange increasing pattern can be achieved by changing the embossing of the band. 14. Tube according to claim 13, characterized by a Change in pattern that increases heat exchange, - 22 - 409847/0945 As a result of a change in the imprint of the band. 15. Tube according to claim 13, characterized in that the heat exchange increasing pattern on the Outside and the inside of the pipe is attached. 16. Tube according to claim 13, characterized in that the heat exchange increasing pattern of a diamond-shaped notched pattern. 17. Tube according to claim 13, characterized in that the heat exchange increasing pattern of a longitudinally directed striped pattern. 18. Tube according to claim 13, characterized in that the pattern which increases the heat exchange is a longitudinal one Contains variation in the arrangement of the heat exchange enhancing pattern. 19. Tube according to claim 18, characterized in that the longitudinal variation in the heat exchange enhancing pattern from a There is a change in the degree of increase. - 23 409847/0945 20. Tube according to claim 13, characterized in that the pattern is formed by smooth sections therebetween is interrupted. 21. Heat exchange tube made of metal, characterized in that it has a weld seam in the longitudinal direction, the wall of the tube in the longitudinal direction has corrugations which extend around the entire circumference of the tube with the exception of the parts of the tube wall on both sides of the weld seam, which are not corrugated and which abut in a straight line and have welded edge parts, the non-corrugated parts of the pipe extend in the same direction with the weld seam and around the circumference outside the weld seam and have a width of less than about 20 % of the pipe circumference, measured at a circle which just encompasses the crests of the corrugations on the outside of the tubes, and the non-corrugated parts interrupt the corrugated parts substantially at the apex of the corrugation. 22. Tube according to claim 21, characterized in that the corrugations have a ratio of pitch to height that varies between 1: 1 and 3 i 1. - 24 - 409847/0945 23. Tube according to claim 21, characterized in that the width of the non-corrugated part is less than about 10 % of the circumference. 24. Tube according to claim 21, characterized in that the length of the tube is at least 50 times greater
than the height of the corrugations .. 25. Tube according to claim 21, characterized in that the sum of the widths of the non-corrugated parts between about 0.38 mm and 2.54 cm. 26. Tube according to claim 21, characterized in that the weld seam is welded by high frequency heating is. 27. Tube according to claim 21, characterized in that the corrugations are formed by smooth sections therebetween are interrupted. 409847/0945 IS Blank page