JPS5812051Y2 - Plate fin type heat exchanger - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a plate-fin type heat exchanger for the production of flammable gas which is designed to prevent gas leakage.

Conventionally, in order to produce flammable gas from liquefied gases such as hydrocarbon, LNG, methane, ethane, and butane by air heating, spacers were used on both side edges of a flow path formed by alternately stacking flat plates and corrugated fins. A plate-fin type heat exchanger was used, which was closed by a bar and had manifolds on the inlet and outlet sides.

However, if the flat plate forming the flow path becomes perforated due to corrosion, or if a gap is created between the spacer 9-bar and the flat plate due to corrosion, gas may leak and scatter into the air. Not only did this reduce vaporization efficiency, but there was also the risk of explosion.

In order to eliminate this drawback, this invention proposes a plate-fin type heat exchanger that is provided with an inert gas flow path around the heat exchange part to prevent gas from leaking to the outside and to detect the leakage. It is something to do.

That is, this invention is a heat exchanger in which both side edges of a passage formed by alternately stacking flat plates and corrugated fins are closed with spacer bars, and manifolds are provided on the inlet and outlet sides of the passage. , leak prevention/sensing passages with built-in corrugated fins similar to the aforementioned passages are provided on the outside of both sides of the heat exchange section, and a leak prevention header with an outer leak prevention/sensing space formed around the upper and lower manifolds is also installed. Outside the spacer bars on both sides of the heat exchanger, leakage prevention and
The gist is that a leak prevention pipe is provided that forms a sensing space and communicates with the leak prevention header.

Next, one embodiment of this invention will be described based on the drawings.

Three flat plates 1 and two corrugated fins 3 are alternately stacked to form a channel 15 having corrugated fins, and both side edges of the channel 15 are closed with spacer bars 2, 2, and the flow is closed. Road 1
A lower manifold 4 is provided on the inflow side of 5, and an upper manifold 5 is provided on the outflow side.

Then, corrugated fins 8.8 and flat plates 6, 6 are superimposed on the outside of both sides of the heat exchanger, and leakage prevention/sensing channels 13.13
and a lower leakproof header 11 with an inlet flange 9 on the inlet side and an upper leakproof header 11' with an outlet flange 10 on the outlet side to form a manifold 4.5 and a leakproof header 11. 11', and leak prevention pipes 17 are formed on both side edges of the heat exchange section to communicate the peripheries of the spacer bars 2, 7 to the leak prevention headers ii, 1i'. .17
to form a leakage prevention/sensing space 16 around the heat exchange part.

In addition, air circulation fins 12 are provided on the outside of both sides of the heat exchanger to improve heat transfer performance, and the outlet flange 1
0 is connected to a flow path (not shown) having a leak detector.0 In the heat exchanger, for example, hydrocarbon is fed from the lower manifold 4 to the flow paths IS, If the hydrocarbon is vaporized while feeding an inert gas such as inexpensive nitrogen gas from the flange 9 into the leakage prevention/sensing channel 13.13, it will act as a heat medium while rising in the channel 15. The air is heat-transferred from the outer fins 12 to the .

At this time, since the heat transfer area is increased by the fins 12, the heat exchange action by the air is performed efficiently.

If the flat plate 1, which is a component of the heat exchanger, becomes perforated due to corrosion, hydrocarbons will flow into the leakage prevention/sensing channel 13, and corrosion between the spacer bar 2 and the flat plate 1 will occur. The gap flows into the outer circumferential leakage prevention/sensing space 16 of the heat exchanger, and further flows into the upper and lower manifolds 4 and 5.
If perforation occurs, it will flow into the outer leakage prevention/sensing space 14, and since the hydrocarbon that has flowed in will mix with nitrogen gas and will not come into direct contact with air, explosions due to leakage can be prevented.

Further, the leaked hydrocarbon is scattered and flows out from the outlet flange 10 into a passage having a leakage detector, and leakage is detected.

As described above, this invention is provided with a leak-prevention flow path in which an inert gas flows around the entire outer circumference of the heat exchange section, and explosions can be prevented because flammable leaked gas cannot be scattered directly into the air.

Furthermore, if a detector is provided in the leakage prevention channel, leakage can be detected quickly, contributing to safe operation.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main parts of this invention, and FIG. 2 is a partially cutaway perspective view of the plate-fin type heat exchanger of this invention. In the figure, 1, 6... flat plate, 2. T...- Spacer bar, 3, 8... Corrugated fin, 4...
...Lower manifold, 5...Upper manifold, 9...Inlet flange, 10...
・Outlet flange, 11.11'... Leak prevention header, 12... Air circulation fin, 13...
... Leak prevention/sensing channel, 14... Outer leak prevention IL/sensing channel, 15... Channel, 16...
... Heat exchanger outer periphery leak prevention/sensing space, 17...
...Leakage prevention pipe, A...Air flow direction.

Claims (1)

[Scope of utility model registration request] Heat exchange is performed by closing both side edges of a flow path formed by alternately stacking flat plates and corrugated fins with spacer bars, and using a heat exchanger with manifolds provided on the inflow and outflow sides of the flow path. Leak prevention/sensing flow paths with built-in corrugated fins similar to the fluid flow paths are provided on the outside of both sides of the section, and air circulation fins are provided on the outer flat plate to form outer circumferential leak prevention/sensing spaces around the upper and lower manifolds. A leak prevention header is provided, and a leak prevention/sensing space is formed on the outer periphery of the heat exchange section outside the spacer bars at both ends of the heat exchange section, and a leak prevention pipe is provided that communicates with the leak prevention header. Plate fin type heat exchanger.