JPS6215668Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a finned heat exchanger tube provided in a boiler or economizer.

An example of a conventional finned heat exchanger tube is shown in FIGS. 4 to 6.

1 is a straight pipe, 2 is a bend part, and the bend part 2 is 180
It is bent at ゜. 3, 3, ... are fins that are welded and fixed to the straight pipe 1, and as shown in Fig. 5, each fin 3 has an arc-shaped recess cut out in one side corresponding to the straight pipe 1. , a pair of fins 3 are disposed in a relationship such that they face each other and sandwich the straight pipe 1 from both sides thereof. Electric resistance welding is usually used as a means for fixing the fins 3 to the straight pipe 1. In this way, one straight pipe 1
A set of unit heat exchanger tubes is constructed by one bend portion 2 and a large number of fins 3 welded and fixed on the straight tube 1, and by sequentially connecting these, a series of boilers or economizers can be constructed. A heat exchanger tube with fins is formed. FIG. 6 shows an example formed by 10 sets of unit heat exchanger tubes (the 10th set does not have the bend portion 2), where 4 is the upper header and 5 is the lower header. 6 is a butt weld between tubes for connecting adjacent unit heat exchanger tubes;
Reference numeral 7 denotes a support fitting, and the support fitting 7 is attached to the bend portion 2 in order to prevent the gap between the flexible pipes from opening due to their own weight.
This is for attaching vertically opposing fins on opposite sides of the fins to each other.

In such a conventional heat exchanger tube with fins, (1) the work of electric resistance welding between the fins 3 and the straight tube 1 is extremely complicated;

(2) Butt welds 6 that connect unit heat exchanger tubes to each other
There are a large number of locations, and as shown in Figure 6, these locations are distributed both on the header side and on the opposite side. It is necessary to have opening/closing doors on both the front and rear sides, which requires a lot of effort and inspection.

(3) It is normal for sulfur to accumulate on the upper end surface of the fins 3, but since there are many fins 3, the amount of sulfur deposited on that part is also large, and the heat transfer efficiency decreases due to sulfur. This will increase heat transfer surface failures such as corrosion.

(4) The required number of supporting metal fittings 7 is large, and as shown in FIG. This makes installation and inspection work inefficient.

It has the following disadvantages.

This invention was made with the aim of improving all of the drawbacks of the above-mentioned conventional equipment, and as a configuration for this purpose, the flexible pipes of the boiler or economizer are connected to each other through the first bend part of 180°. Two straight pipes connected in parallel to each other and a second bend of 180° formed along the same plane at the free end of one of the two straight pipes. It is constructed by sequentially connecting multiple sets of unit heat exchanger tubes, and has two arcuate recesses on one side corresponding to each of the two parallel straight tubes of the unit heat exchanger tubes. A pair of rectangular plate-shaped fins formed by notches are welded and fixed to the side surfaces of the straight pipes at positions that sandwich the above-mentioned two straight pipes from both sides, facing each other, and placed on each adjacent unit heat exchanger tube. The fins, which are located opposite to each other in the vertical direction on the opposite side of the second bend portion, are fixed to each other by means of a support fitting.

Next, one embodiment of the finned heat exchanger tube according to this invention will be described in detail with reference to the drawings.

In FIGS. 1 to 3, 8 and 8a are two straight pipes connected to each other in a parallel state through a first bend 9 of 180 degrees. The straight pipe 8a has a second bend part 9a of 180° formed along the same plane at its free end, and the straight pipes 8, 8a and the bend parts 9, 9a form a set of unit heat exchanger tubes. Configure. Reference numeral 10 denotes a rectangular plate-shaped fin, which has two arc-shaped recesses 11, 11 cut out on one side thereof, corresponding to the two straight pipes 8, 8a, respectively, so that the pair of fins 10, 10 are cut out from each other. The straight pipes 8 and 8a are welded and fixed to the side surfaces of the straight pipes at positions that sandwich the straight pipes 8 and 8a from both sides simultaneously. By sequentially connecting a plurality of unit heat exchanger tube sets constructed in this way through the butt welds 6, a flexible tube provided in a boiler or economizer is constructed. Reference numeral 7 denotes a support fitting for fixing the fins on the adjacent unit heat exchanger tubes and facing each other in the vertical direction on the opposite side of the second bend portion 9a. Figure 3 shows five sets of the unit heat exchanger tubes (the fifth set is the second bend part 9).
In this example, each unit heat exchanger tube is provided with a total of four supporting metal fittings 7 to prevent the interval between the heat exchanger tubes from widening due to drooping due to their own weight. As is clear from a comparison between FIG. 6 showing the conventional heat exchanger tube and FIG. 3 showing the heat exchanger tube of the present invention, the number of support fittings 7 required to construct the flexible tubes with the same number of stages is In Fig. 3, there are 4 pieces, and in Fig. 6, there are 9 pieces, which is about half of the number in the present case. This is because the fins 10 also have the function of a supporting metal fitting. Moreover, the third
In the case of the figure, all the installation locations of the support metal fittings 7 are concentrated on the opposite side of the header, so the support metal fittings 7 are concentrated on the opposite side of the header.
Installation and inspection work is easy.

In order to weld and fix the fins 10 to the side surfaces of the straight pipes 8 and 8a, electric resistance welding is usually used. Compared to the conventional method shown in Fig. 4, the electric resistance welding process is more efficient in that two places can be welded simultaneously with one touch. It's much better.

In this embodiment, the shape of the fins 10 has been explained using a rectangular flat plate as an example, but the rectangular plate constituting the fins is not limited to a flat plate. In some cases, it may be a rectangular plate, and the scope of the claims of the present application naturally includes such fins.

The heat exchanger tube with fins according to this invention is constructed as described above, and therefore, (1) welding between the fins and the straight tube is simple and easy, and the welding process is reduced by about half compared to the conventional method; , the manufacturing period will be shortened.

(2) Since two straight pipes are used to construct a unit heat exchanger tube for one reciprocating circuit, the butt welding area is smaller than the conventional method, which uses a single straight pipe to construct a unit heat exchanger tube. The number of welded parts is reduced by about half, which simplifies the work and at the same time reduces the number of welded parts to be inspected, thereby improving the reliability of the product and contributing to quality improvement. In addition, because the unit heat exchanger tube is one reciprocating circuit, all butt welds are concentrated on one side of the boiler or economizer, and a door for inspection and inspection only needs to be provided on one side. In addition to simplifying the device, the labor of inspection and inspection can be greatly reduced.

(3) The upper end surface of the fin, where sulfur is likely to accumulate, is reduced by half compared to the case of the fin in the example shown in FIG. 4, and damage to the heat transfer surface due to sulfur can be reduced.

(4) Compared to the example shown in Figure 4, which shows an example of a conventional device, the required number of supporting metal fittings 7 is reduced by about half, and moreover, they are concentrated on one side of the boiler or economizer, so that the supporting metal fittings 7 are concentrated on one side of the boiler or economizer. Installation and inspection of metal fittings can be carried out efficiently.

It has excellent effects such as

[Brief explanation of the drawing]

Fig. 1 is a front view of the main parts of the proposed device, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is an overall external view of the proposed device, and Fig. 4 is a front view of the main parts of the conventional device. 5 is a sectional view taken along the - line in FIG. 4, and FIG. 6 is an overall external view of the conventional device. 1, 8, 8a... straight pipe, 2, 9, 9a... bend part, 3, 10... fin, 4... upper header,
5...Lower header, 6...Butt welding portion, 7...Supporting metal fittings, 11...Recessed portion.

Claims (1)

[Scope of utility model registration request] The serpentine pipe of the boiler or economizer,
Two straight pipes connected parallel to each other via a first bend portion of 180°, and a 180° pipe formed along the same plane at the free end of one of the two straight pipes. It is constructed by sequentially connecting a plurality of unit heat exchanger tube sets constituted by the second bend portion of A pair of rectangular plate-shaped fins formed by cutting out two arcuate recesses on one side of the fins are placed opposite each other and welded and fixed to the side surfaces of the straight pipes at positions that sandwich the two straight pipes from both sides. , a heat exchanger tube with fins, in which fins located vertically opposite each other on the opposite side of the second bend portion on adjacent unit heat exchanger tubes are engaged with each other by a support fitting. .