JP3038104B2 - Double-tube liquefied natural gas vaporizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-tube liquefied natural gas vaporizer for vaporizing liquefied natural gas, and more particularly to a support structure for a bottom portion of a heat transfer tube.

[0002]

2. Description of the Related Art As shown in FIG. 4, a double-tube liquefied natural gas vaporizer sends LNG to the inner tube side of a heat transfer tube 1 having a double-tube structure via an LNG header 2 → a vent tube 3. The heat is transferred into the outer tube at the bottom of the heat transfer tube 1, the heat is exchanged with seawater sprinkled from the trough, the gas is vaporized, collected in the NG header 4, and then sent to the consumer side.

As shown in FIG. 5, the bottom of the heat transfer tube 1 has a structure in which a boss 7 is sandwiched and fixed from both sides by an L-shaped long steady rest jig 5 having a bakelite 6 attached to the inside thereof. is there.

[0004]

Therefore, there are the following disadvantages.

A. Since the heat transfer tube 1 is completely fixed by the steadying jig 5, the heat transfer tube 1 side receives a large load particularly when the heat transfer tube 1 expands and contracts due to a thermal load at the time of startup.

B. Since the seawater sprinkled from the trough directly flows down to the horizontal portion 5 'of the L-shaped steady rest jig 5 as shown in FIG. 5, a large amount of seawater scatters around as shown by an arrow a.

An object of the present invention is to solve the above-mentioned disadvantages a and b in a double-pipe liquefied natural gas vaporizer.

[0008]

The construction of the double-tube liquefied natural gas vaporizer according to the present invention is as follows.

A boss having a vertically downward supporting portion is attached to the bottom of the heat transfer tube, and a steadying jig having a trapezoidal cross section is arranged along the bottom of the bottom of the heat transferring tube. A double-tube liquefied natural gas vaporizer having a structure in which a support hole is provided and a support portion of the boss is slidably inserted into the support hole.

In order to minimize the amount of seawater flowing down from above, the cross section of the steady jig is preferably formed in a trapezoidal shape close to a triangle or in an arc shape on both sides.

[0011]

[Function] When a heat load is applied to the heat transfer tube and it expands and contracts, the bottom of this heat transfer tube absorbs the expansion and contraction by the slide action because the support part of the boss only slides freely into the support hole of the steadying jig. No load is applied to the heat transfer tube.
In addition, the seawater sprinkled from the trough has a small hitting angle and does not scatter greatly because the outer shape of the steady jig is inclined or curved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a double-tube liquefied natural gas vaporizer embodying the present invention.
Is an LNG header, 12 is a vent tube, 13 is an NG header, 14 is an inner tube in the heat transfer tube 10, 15 is an outer tube, 16 is a steadying jig, and a support structure of the heat transfer tube 10 by the steadying jig 16 is shown. As shown in FIG. In this figure, reference numeral 17 denotes a heat transfer tube 1 welded 18 to the bottom of the heat transfer tube 10 (outer tube 15).
The boss 17 has a shape in which a round bar-shaped support portion 19 is integrally formed vertically downward, and the support portion 19 is provided on the steady rest jig 16 for each heat transfer tube 10. Each is slidably inserted into a vertical support hole 20. In addition, although the support part 19 of an Example is a round bar shape, it may be a square bar shape. However, in the case of a square rod shape, the support hole 20 is also made square according to this.

Although the cross-sectional shape of the steadying jig 16 in the above embodiment is trapezoidal, both sides 16a may be formed in an arc shape as shown in FIG.

In the above embodiment, when the heat transfer tube 10 expands and contracts due to a thermal load, the support portion 19 of the boss 17 moves the jig 1
6 is slidably inserted into the support hole 20, so that the load applied to the heat transfer tube 10 is absorbed. In addition, vaporization tube 1
The seawater that has flowed down from troughs (not shown) disposed on both upper sides of the upper part 0 has a smaller angle at which it flows down because both sides 16a of the steadying jig 16 are formed in an inclined or arc shape. Do not fly around.

[0015]

As described above, according to the present invention, since the bottom of the heat transfer tube is slidably supported, expansion and contraction of the heat transfer tube generated by the heat load is absorbed, and no load is applied to the heat transfer tube itself. As a result, it is possible to eliminate the trouble of the heat transfer tube that occurs particularly when a large heat load is applied during startup.

Next, according to the present invention, the shape of the steady rest jig is such that the flowing seawater is not scattered.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a double-pipe liquefied natural gas vaporizer embodying the present invention.

FIG. 2 is an explanatory view of a bottom support structure of a heat transfer tube.

FIG. 3 is an explanatory view in a case where both sides of a steady rest jig are formed in an arc shape.

FIG. 4 is an explanatory view of a conventional double-tube liquefied natural gas vaporizer.

FIG. 5 is an explanatory view of a conventional heat transfer tube bottom support structure.

[Explanation of symbols]

 Reference Signs List 10 heat transfer tube 11 LNG header 12 vent tube 13 NG header 14 inner tube 15 outer tube 16 steady rest jig 16a both sides 17 boss 18 welding 19 support portion 20 support hole

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyasu Miura 38-37-402, Shirahata-Kamicho, Kanagawa-ku, Yokohama-shi, Kanagawa-ken (72) Inventor Shinichi Kasahara 6-9-5-28, Chuo, Ota-ku, Tokyo (72) Inventor Hitoshi Shoya 61, Kitajo, Amagasaki City, Hyogo Prefecture (72) Inventor Yu Akiyama 2-12-1-3, Satsurakudai, Kizu-cho, Soraku-gun, Kyoto Prefecture (72) Inventor Yoshiro Tonoike 2- Konakajima, Amagasaki City, Hyogo Prefecture 20-18 (56) References JP-A-59-3174 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F17C 9/00-9/04 F28D 7/10 F28D 3 / 00-3/02

Claims (2)

(57) [Claims] 1. A boss having a vertically downward supporting portion is attached to the bottom of a heat transfer tube, and a jig having a trapezoidal cross section is arranged along a lower portion of the bottom of the heat transfer tube. A double-pipe liquefied natural gas vaporizer having a configuration in which a support hole in the direction is provided and a support portion of the boss is slidably inserted into the support hole. 2. The double-tube liquefied natural gas vaporizer according to claim 1, wherein a cross section of the steady rest jig is formed so that both sides are arcuate.