JPS58209432A - Manufacture of boiling heat transfer pipe - Google Patents

Abstract

PURPOSE:To manufacture continuously a pipe for heat transfer with boiling having an excellent boiling heat transfer rate, by forming a circumferential cavity opened by opening parts arranged regularly in the circumferential direction of a pipe. CONSTITUTION:Each independent projection-like fin F is formed on a blank pipe on which a lot projecting lines 4 and longitudinal grooves 2 extending in the pipe axial direction are formed alternately, by a rolling tool on which plural disks are placed. Also, in the latter half stage of the roll-working, a lot of independent projection-like fins F having a projecting tip part Fa are formed in the circumferential direction. A heat transfer finned pipe is made to pass through a die 8 and is push-elongated, and the projecting tip part Fa of each fin F is drawn extending over the whole circumference in the opposite direction to the push-elongating direction. The promecting tip part Fa of each fin F is incline-deformed and only each projecting tip part Fa placed in series in the axial direction is made to press-contact with each other. Accordingly, a circumferential cavity 10 opened by opening parts 11 arranged regularly in the circumferential direction is formed continuously on the surface of the blank pipe 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a high-performance boiling heat exchanger tube used in a boiling heat exchanger. It is made to form continuously and stably.

A heat transfer tube that effectively transfers heat to liquids such as chloride, liquid oxygen, alcohol, water, etc. that come into contact with the surface of the tube;
In order to increase the heat transfer efficiency of so-called boiling heat transfer tubes, it is necessary to improve the boiling heat transfer characteristics, especially at low temperature differences.

Therefore, when manufacturing boiling heat exchanger tubes, there are many fine openings or gaps that communicate from the inner wall of the tube toward the outer wall of the tube in a wide-spread shape, and cavities or tunnels that connect these to each other. It is devised so that it is finally formed. The specific method is 1i1. ■～■ are known.

■This method is performed by sintering metal powder to form a porous layer on the outer surface of the tube.

(2) A method in which spiral fins with four large serrated teeth are formed on the outer surface of the tube by cutting them up with a cutting tool, and then the fins are pushed down in the direction of the tube axis using a wire brush to form a tunnel-like cavity with an opening.

■ In conventional fin processing, the upper part of the fin is divided by plastic deformation, and the shoulder part of the upper part of each fin is compressed to form a lateral extension part. K. A tunnel-shaped cavity with multiple openings. After that, the fins are partially compressed to form a wall side with a wide opening and a narrow opening.

However, method (2) involves a sintering operation during the moving process, resulting in low productivity (and high cost).
!It is difficult to obtain a uniform shaft hole diameter due to the high Q+i.Also, in the method of
Since this is done by plowing and raising, productivity is low in this case as well, and there is a risk that the tube may break due to the progression of microcracks that occur during the plowing. Furthermore, in method (2), it is necessary to prevent the fins from buckling during the compression deformation operation, but it is extremely difficult to perform such an operation well, and the manufacturing equipment is complicated and expensive. I have no choice but to.

The present invention was made in view of these circumstances, and its purpose is to continuously, stably, and economically produce boiling heat transfer tubes with high performance, that is, excellent boiling heat conductivity. I'm trying to provide a way to do that.

However, the manufacturing method of the present invention, which has achieved these objectives, consists of a tube in which a large number of straight or spiral protrusions and diagonal grooves extending in the V-axis direction are formed alternately on the outer surface of the tube. The projections and longitudinal grooves are divided in the axial direction to form independent projecting fins, and a circumferential groove continuous in the circumferential direction is formed on the outer surface of the tube, and further, By deforming the pant part by the pressing force in the axial direction and bringing the tip of the core into contact with the axially adjacent fins, the circumferential air space opened by the openings regularly arranged in the circumferential direction is created. The gist is that it causes spines to form.

The structure and effects of the method of the present invention will be explained below based on the first example. The embodiment merely shows one representative example, and it is of course possible to implement it with appropriate changes in accordance with the spirit of the preceding and following descriptions, and even in that case, it is within the technical scope of the present invention. It's no good.

N4.1 is a partial sketch of the raw pipe 8 for rolling processing in the present invention, and is made of heat conductive materials such as Cu and Al (including alloys). On the outer peripheral side of the tube 8, a large number of linear or spiral protrusions 4 and longitudinal grooves 8 extending in the tube axis direction are alternately formed. The base pipe 8 with such protrusions and grooves can be well formed by, for example, a hydrostatic extrusion method, a drawing method, or the like. In the present invention, such a raw pipe is used, and as described below, by rolling processing with a rolling disk, the protrusions 4 and the vertical grooves 2 are divided in the axial direction, and in the direction perpendicular to the pipe axis. Further, it can be formed into a raised shape to form a large number of independent protruding fins.

If the cup is removed, Fig. 2 is a rear view (1 viewed from the left side of Fig. 8) illustrating the rolling a forming situation, No. 8 1 is an explanatory cross-sectional view of the main part, and Fig. 4 is FIG. 3 is an enlarged view, and FIG. 5 is a cross-sectional view corresponding to the v-v line in FIG. 4. 8 is a mandrel for regulating the inner surface, 6 is a rolling tool (generally composed of a set of 8 pieces as shown in Fig. 2), and the rolling tool 6 is as follows: A plurality of disks whose diameters become larger sequentially as they move toward the right side of Fig. 8 are arranged,
Each disk is plated on the support glaze 7 so that it can rotate freely in the circular direction (i.e., can rotate in the direction of arrow B at different circumferential speeds independently), and in the fixed position as a whole in the direction of arrow HH'c (second direction). (Figure). Therefore, "Honour" 8 and Mandrel 5
While moving straight in the direction of arrow A while regulating the
By pressing and rolling the entire rolling tool 6 on the outer surface of the element Mf8 in the direction of arrow C, the protrusions 4 and the vertical grooves 2 on the outer periphery of the element tube 8 are removed.
are divided in the axial direction to form independent protruding fins F, as shown in FIG. In the latter half of the rolling process, the disk is pushed deepest into the vertical groove 2 on the surface of the raw pipe 8, so the outer surface of the raw pipe 8 is covered with continuous &D'e in the circumferential direction.
At the same time, the fin F grows upward in the direction perpendicular to the tube axis due to the tube n left over after being pushed. Finally, as shown in Fig. 5 and Fig. 6 (partial sketch drawings illustrating the outer surface shape of the tube after the rolling process is completed), J+ is finally formed into an independent protruding fin F having a wearing tip &1SFa. are numerous in the circumferential direction J13. It will be done.

Thus, fin processing No. 1. After that, the heat transfer tube 1 is elongated by passing it through a die 8 having an inner diameter smaller than the outer diameter of the tube. Set larger than r.By this drawing, the protrusion tip pa of each fin F
is narrowed over the entire circumference in the direction opposite to the drawing direction (arrow direction), so as shown in Fig. 7, the protrusion tips pa of each fin F are all tilted and deformed, and are aligned in series in the axial direction. Only the tip ends Fa of the respective protrusions contact each other. That is, in Figure 8, p
a,,Fa'.

Fa// (hereinafter simply referred to as pa when speaking representatively) are in series in contact with each other in the axial direction. Figure 9 shows the tip of each protrusion F.
Fig. 1 shows an enlarged cross-sectional view of the main part when the heat exchanger tube 1' is cut in the longitudinal direction along a line connecting the centers of ``a'', FW, and Fa''. This shows the state in which the tip of the protrusion Fa is securely in contact with the wood board A.

In addition, each fin longitudinal surface 2, 2', 2'' (
(Hereafter, when speaking representatively, it will simply be written as 2) are far apart from each other.

),! IJ Chi Kozue lO and J is each fin it? r++i 2
Heat exchanger tube 1'τht with a line connecting the centers of m2'm2''
10,000 times, #i "L, and the need for shame expands! 17r side to 1, but each fin 4 to 7 Fili, 2. no' listen to Yul
White 11117 It has the same name as the width of S, and is made in the same way.

Through the above process, the circular layer wall side lO opened by the openings 11 arranged in the #A 14+7 correctly at all times,
It can be molded 1" on the surface of the raw pipe 8.

Made in this way? The B11 rise heat transfer performance of the heat transfer tube 1' was extremely excellent, and its effects can be briefly described as follows:
) ml) C-h le,, E41J Chiden 1t! k 91'
k m A a M When the body dp is infested and a substance is poured into ', the liquid is heated, but especially the liquid in the wall side 11 rises and creates air bubbles. do. The generated bubbles grow inside the cavity 1O and escape from the heat exchanger tube 1' by passing through the opening 1fls11'i. That is, heat exchanger tube 1'
Comparing the individual DtJ openings and the individual protrusion tips, the former has a smaller size in the a direction per l, and its shape is also 1. Since the opening widens toward the end, 1fb of 9Lc foam with boiling kW of % is '9. It will remain in the cave for 10 days. However, since the remaining (shavings) form a strong jαM in the cavity lO, the heat transfer resistance does not become so large.As a result, the lα body can efficiently (boil) - 10,000, when the air bubbles form on both arms of the H8 raised body, open the other openings 11 where air bubbles are not generated.
Efficient from <intrusion,? Supply will be supplied to areas where Jli rise is actively occurring. In this way, the N1 rise progresses efficiently and continuously, and as a result, the boiling heat transfer performance of the heat transfer tube 1' is greatly improved.

By the way, the above manufacturing process does not include the conventional φ-tying process, which is highly productive, and the fin processing is performed by pressing and rolling the disc for rolling ∆ instead of using a cutting tool to create a fin. Since it is scooped, productivity is good and there is little risk of small cracks forming in the cavity. Furthermore, the above-mentioned openings and cavities can be formed by dividing the upper fin Ob as in the conventional method and also applying pressure to the shoulder part of each fin upper 11 in the shape of Jfdl and extending it laterally. Instead, the fin tip fffil Gb is entirely VA obliquely deformed by an axial pushing force and brought into contact with the adjacent fin, so there is no risk of the fin buckling. There is no need for any mechanism or process to prevent the occurrence of buckling, and the configuration of the manufacturing equipment can be simplified.

In the embodiment described above, the fin was deformed using a die, but for example, as shown in FIG. 11, a pair of low/l/12,1
It is also possible to press 2' against the heat exchanger tube 1.

Furthermore, when this roll method is adopted, rolls 12 and 12' are placed behind the rolling tool 6 (on the arrow A side) shown in FIG.
By installing the heat exchanger tube 1' and manufacturing the heat exchanger tube 1' in one step, the productivity of the heat exchanger tube 1' can be further improved.

The manufacturing method of the present invention is roughly configured as described above, but the key point is that the fins are arranged regularly in the circumferential direction by continuously performing fin forming processing by rolling and fin inclination deformation processing by axial pressing force. The circumferential cavity released by the opening is efficiently and stably formed on the tube surface, making it possible to provide l, IB heat exchanger tubes with excellent bacterial performance at a very economical cost. Ta.

[Brief explanation of drawings]

Fig. 1 is a partial sketch diagram illustrating the raw pipe used in the present invention, Figs. 2 to 10 show examples of the present invention, and Fig. 2 is a view seen from the back side during the rolling process. , @ Figure 8 is an explanatory longitudinal cross-sectional view of the main part showing the rolling situation, Figure 4 is an enlarged view of the part ■ in Figure 8, Figure 5 is a cross-sectional view equivalent to the v-v line in Figure 4, and Figure 6 is the rolling diagram. Fig. 7 is a partial view illustrating the shape of the protruding fin after photon processing, and Fig. 7 is a vertical view of the main part showing the tilt deformation processing status of the protruding fin. 8 is a partial perspective view illustrating the shape of the finished fin, and FIGS. 9 and 10 are enlarged views of the IK-11 line and XX line 011 of FIG. 8, respectively. 1
FIG. 1 is a diagram corresponding to FIG. 7 in another embodiment. 1.1'... Heat exchanger tube 2... Vertical IR8...
Raw pipe 4... Protrusion 5... Mandrel
6.1. Rotating tool 7... Support shaft 8...
Dice 12.12'-...o-ru p...Protruding fin Fa...Protrusion tip S...NON# Applicant
Kobe Kokosho Co., Ltd. q, y'ΔV-,'- Procedural amendments (issued by 岨) August 12, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi Japan Patent Office Chief Examiner Examiner of the Japan Patent Office
1. Display of the case 1982 Patent Application No. 91926 SI
Showa No. 2 Name of the invention or device fJB It TMa method 3 of heat exchanger tubes, relationship with the case of the person making the amendment Patent Applicant Location 3-18 Wakihama-cho, Chuo-ku, Kobe Name (119) Stocks Company: Kobe Steel, Ltd. Representative: Kokichi Takahashi 4, Agent Postal code: 530 Address: 2-3-7 Dojima, Kita-ku, Osaka Shinko Building This is a separate paper type engraving (the corrections are not included). Procedural amendment (voluntary) September 21, 1980 Director General of the Japan Patent Office Kazuo Wakasugi Chief Examiner of the Japan Patent Office Examiner of the Japan Patent Office
1. Indication of the incident 1982 Patent Application No. 91926 C) Showa
Year No. 2, Name of the invention or device Manufacturing method for boiling heat exchanger tubes 3, Relationship with the case of the person making the amendment Patent Address: 3-18-4 Wakihama-cho, Chuo-ku, Kobe City, Agent
Postal code: 530 Address: Shinko Building 7, 2-3-7 Dojima, Kita-ku, Osaka Contents of the amendment (1) "Therefore...
"Towards" should be corrected to "Therefore, when constructing such lvI heat transfer tubes, from the outer wall of the tube to the inner wall of the tube." (2) Corrected "high heat conductive material" in the 8th line of the 5th shell to "metallic material" for 1 piece. (3) On page 6, lines 2 to 11, “Each disk has a spindle 7
``Each disk is fixed to the spindle 7 and rotates in the B direction.As a result, the raw tube 8 rotates and moves straight in the input direction, and the outer circumference of the raw tube 8 Convex strip 4
and vertical groove 2 is divided in the axial direction as shown in Figure 8.'' (Replace Drawing 41, Figure 2, with the attached sheet. Go to Figure 2, 6 f

Claims (1)

[Claims] +l) A rolling disk is compressed and transferred onto the outer surface of a tube in which a large number of linear or spiral protrusions and longitudinal grooves extending in the axial direction are formed alternately to form the protrusions and longitudinal grooves in the axial direction. dividing to form independent protruding rod fins, forming circumferential grooves continuous in the circumferential direction on the outer surface of the tube, and further tilting and deforming the protruding tips of the fins by pressing force in the axial direction,
A boiling heat exchanger tube characterized in that by bringing the tip of the protrusion into contact with 1 to 4 fins in contact with each other in the axial direction, a circumferential cavity is formed with openings regularly arranged in the circumferential direction. IM manufacturing method.