FI59667B - FOER ANVAENDNING I EN VAERMEVAEXLARE AVSETT ROER - Google Patents

Description

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Sweden- Sverige (SE) 6671/72 (71) AGA Heating AB, Mölndalsvägen 85, hl2 85 Gothenburg, Sweden-Sverige (SE) (72) Helge Jonasson, Ronneby, Sweden-Sverige (SE) (7M Oy Kolster Ab (5M The present invention relates to a heat exchanger, which is e.g. with a special design to increase the efficiency of heat transfer from one medium to another so that a heat exchanger for a given heat transfer efficiency can be made to a lesser extent than has hitherto been possible.

The invention is characterized in that the tube is formed on the outside with three or more grooved recesses extending helically to the right, rotating to the right and rising, which substantially exceeds the diameter of the tube, and with a corresponding number and same pitch, turning to the left. a grid pattern of recesses, which on the inner side of the tube corresponds to a grid pattern formed by ridges running intersecting with respect to each other. The ridges give the pipe greater strength against external pressure. In addition, they contribute to it.

2,59667 that the pipe, when bent, retains its cross-section, and that when fluid is passed through the pipe, this causes an increasing turbulent flow along the wall of the pipe and thus an increase in the heat transfer rate.

It is further preferred for the pipe according to the invention that the helical grooves and the ridges, respectively, have such a pitch that the squares have approximately the same axial and circumferential dimensions.

The invention will now be described in more detail with the aid of the accompanying drawings.

Fig. 1 is a perspective view, Fig. 2 is a side view and Fig. 3 is a cross-sectional view of a tube shaped in accordance with the invention.

Fig. 4 shows, in axial section and Fig. 5, an end view of a tube package consisting of three tube coils rotating to the right, tightly on top of each other.

Kuyio 6 shows, in axial section and in the end view of Fig. 7, a tube package consisting of three tubes, telescopically inserted into each other or wrapped tightly on top of each other, alternately wrapped to the right and left.

Figures 8 and 9 show the basic structure of a tool for making helical depressions in a pipe drawn through a tool.

The tube according to Figs. screen model. The pitch of the grooves substantially exceeds the diameter of the tube so that the substantially diamond-shaped squares acquire at most the same axial and circumferential dimensions. The square shape of the intersecting grooves 10 and 11 on the outer side of the tube corresponds to the square pattern formed by the ridges on the inner side of the tube. These ridges, when passing liquid through the pipe, cause the liquid to be forced into an increased turbulent flow in the vicinity of the pipe wall, as a result of which the heat transfer number increases so that a heat exchanger for the same power can be realized with a smaller heat transfer surface.

Figures 4 and 5 show a pipe package consisting of three pipe threads 12, 13 and 14 wound tightly on top of each other in such a way that a three-part distribution of the pipe in cross-section is obtained. The tube package is tightly surrounded by an inner wall cylinder 15 and an outer wall cylinder 16. The tube threads are thought to be in parallel for flow through the tubes from top to bottom, while the surrounding flushing liquid is thought to flow from bottom to top through the annular space, which is enclosed is for the most part a pipe package fill-this. The intersecting grooves define flow channels having a sufficient cross-sectional area for the liquid to be flushed around.

In the heat exchanger according to Figures 6 and 7, a tube package consists of three tube threads 17, 18 and 19 telescopically inserted into each other or wrapped on top of each other, which are alternately wrapped in a right-handed and a left-handed model. Here, too, the pressed grooves on the outside of the pipe define sufficient flow channels for the liquid flushing around the pipes.

The tool shown in Figures 8 and 9 is intended to provide recesses in the pipe wall, which forms a four-threaded screw. Attached to the retaining ring 20 are four radially directed bolts 21 evenly distributed along the circumference, which are formed at their inner end as a fork 22 on which a disc 23 is rotatably mounted. These bolts 21 are locked by nuts 24 and 25 in such positions that the circumferential surface of said disc the plane passing through forms an acute angle with respect to the common plane passing through the axis of the four bolts. The tool is mounted for rotation about the axis 20 of the ring. As the pipe is pulled through the tool along the axis, the four discs 23 press four helically grooved grooves running smoothly relative to each other into the pipe wall, which grooves on the inner side of the pipe correspond to four helical ridges. A similar tool with discs mounted obliquely in the opposite direction is used to press four recesses rotating in the opposite direction.