DE2325409A1 - ARRANGEMENT ON HEAT EXCHANGERS - Google Patents

Description

Applicant in: Aktiebolaget CTG, Göteborg / Scliweden

Arrangement on heat exchangers.

The present invention relates to heat exchangers, for example of the conventional Sgenstrom type, in particular of the type in which one medium flows through tubes usually wound in the form of a screw diaper, that of the second Medium.

The purpose of the invention is to increase the effectiveness of the heat transfer from one medium by means of a special shape of the drilling walls on the other hand to increase, so that for a certain heat transferL effect of heat exchangers with smaller dimensions than before possible. For this purpose, according to the invention the pipe used can be formed on the outside with three or more groove-shaped impressions, which run helically in clockwise rotation with a slope; which considerably exceeds the diameter of the pipe, and with a corresponding number with the same pitch in left-hand rotation Helical indentations so that • a square pattern of indentations is formed on the outside of the pipe which corresponds to a pattern of intersecting crests on the inside of the pipe, which gives the pipe a higher strength against external pressure, contribute to that Pipe retains its cross-section when it is curved and when it is penetrated of a fluid through the pipe, an increased turbulent flow along the pipe wall and thus an increase in the heat transfer coefficient cause.

309849/0934

23254G9

The formation of a pipe with a square pattern according to the " Finding can advantageously be done by pulling the pipe successively through two rotatably mounted tools, each having three or more rotatable bearings around its iSdise, Discs arranged in a circle around the axis of rotation of the tool, the plane of which is at an acute angle to the axis of the Forms tool, with the disks of one tool inclined, are for the purpose of pressing into the pipe wall of grooves, the run helically in clockwise rotation, and the discs of the second tool are adjusted for the purpose of blackmailing grooves, which run helically in counter-clockwise rotation.

The invention also relates to a heat exchanger from Countercurrent type, in which one medium flows through tubes wound in the form of a very hooded diaper, which are on the inside with a square pattern of "intersecting crests and on the outside with a corresponding square pattern of itself intersecting grooves are formed. If the grooves are chosen sufficiently deep, the screw turns with the turns directly next to each other are twisted because the grooves Throughflow channels of the required cross-section for the pipes Form umspühlende Fluiduui.

The invention will now be explained in more detail with reference to the accompanying drawing. It shows:

Fig. 1 in perspective, Figure 2 _c shows a side view and Fig. 3 a cross section of an inventive, pipe executed with "square pattern}

Fig. H a Axialsektion and Figure 5 is a plan view of a tube packet, consisting of three closely together in right turn coiled tubing windings.

FIG. 6 shows an axial section and FIG. 7 shows a plan view of a tube package, consisting of three telescopically inserted or tightly wound, alternating in Clockwise rotation and tubes wound in counter-clockwise rotation

FIGS. 8 and 9 show the basic structure of a tool for executing helical impressions in a pipe pulled through the tool.

309849/0134

The tube according to Fig. 1-3 is designed with four, equally spaced, successive, helical, groove-shaped Indentations 10, and with four, at the same distance from each other, in a counter-clockwise direction in a helical manner, Groove-shaped impressions 11 “The intersecting grooves 10 and 11 together form a square pattern. The slope of the groove & n is much larger than the diameter of the pipe, so that the mainly rhombus-shaped quadrilaterals have essentially the same axial and peripheral extension. A square pattern corresponds to the square pattern of intersecting grooves 10 and 11 on the outside of the pipe of combs on the inside of the pipe. When a fluid is passed through the pipe, these combs cause the Fluid around an increased turbulent flow is forced on the pipe wall, whereby the heat transfer coefficient increases, so that for the same effect the heat exchanger with a lower heat transfer area can be performed.

In FIGS. H and 5, a tube package is shown, consisting of three tube windings 12, 13 and I ¹ + wound close to one another in such a way that a triangular division of the tubes is obtained in cross section. The tube package is tightly enclosed by an inner wall cylinder 15 and an outer wall cylinder 16. It is assumed that the pipe windings are coupled in parallel from top to bottom for the purpose of flowing through the pipes, while the fluid flowing around it flows from bottom to top through the annular space which is closed between the cylinder walls and largely filled by the pipe package _a The intersecting grooves of the tubes form flow channels with a sufficient flow area for the surrounding fluid.

In the heat exchanger according to Fig _o 6 and 7, the tube package consists of three interacting telescopically pushed-in or sequential coiled tube convolution s 17,18 and 19, which are alternately wound in clockwise rotation and counterclockwise rotation * Again, the pressed-in grooves formed on the outside of the tubes sufficient flow channels for the fluid flowing around the pipes.

The tool shown in Figs. 8 and 9 has the task. A-

309349 /

To bring about pressures in the pipe wall, which form a four-thread screw. Fastened to a retaining ring 20 are four radially directed bolts 21 which are evenly distributed around the circumference and which are formed at their inner end with a fork 22 in which a wheel 23 is rotatably mounted. Each bolt 21 is fixed by nuts 2h and 25 in such positions that the plane through the periphery of each wheel forms an acute angle to the common plane through the axles of the four bolts. The tool is mounted for rotation about the axis of the ring 20. When pulling a pipe through the tool along the axis, the four small wheels 23 press four helical grooves running next to one another into the pipe wall, which grooves on the inside of the pipe correspond to four helical channels. A similar tool, but with the wheels inclined in the opposite direction, is used to press four grooves in opposite directions.

309849/0934

Claims (3)

Patent claims ■ _x Ί · / A pipe intended for use in a heat exchanger for the passage of the one fluid _5, characterized in that the pipe is formed on the outside with three or more groove-shaped impressions, which run helically in a clockwise direction with a pitch that substantially reduces the diameter of the pipe and with a corresponding number of indentations running helically to the left with the same pitch, so that a square pattern of indentations is formed on the outside of the pipe, which corresponds to a square pattern of intersecting ridges on the inside of the raw material, which gives the pipe greater strength give external pressure, furthermore contribute to the fact that the pipe retains its cross-section during bending and the passage of a fluid through the pipe causes an increased turbulent flow along the pipe wall and thereby an increase in the heat transfer coefficient. 2. Pipe according to claim 1, characterized in that, the helically extending ^; Grooves or ridges have such a slope that the quadrilaterals have essentially the same "axial as peripheral extent". 3. Method of forming a pipe with outside Press-ins and corresponding inside combs Claim 1 or 2, characterized in that the tube is consecutive is pulled by two rotatably mounted tools, each having three or more rotatable about its axis mounted discs arranged in a circle around the axis of the tool, the plane of which is at an acute angle to the longitudinal axis of the Forms tool, the discs of one tool are inclined to be pressed into the pipe wall of grooves that run helically in clockwise rotation, and the discs of the second tool are set to impress Grooves that run helically in counterclockwise rotation, H. . Heat exchanger of the counter-flow type, in which the one fluid flows through tubes wound in helical form, which are surrounded in counter-flow by the second fluid, characterized in that the tubes are shaped according to claim 1 or 2 309849/0934 and the screw turns are directly adjacent to one another, wherein the pressed-in grooves on the outside of the pipe or the pipes required flow channels for the die'Rohrwindungen Form surrounding fluid. 309849/093 / » Blank page