JPH0792360B2 - Metal combustor manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a metal combustor that utilizes a reaction between an alkali metal and an oxidizer used in a propulsion system for underwater vehicles.

[Conventional technology]

In a conventional metal combustor that oxidizes and burns the combustion of an alkali metal such as lithium with an oxidant such as sulfur hexafluoride, a preheating agent such as a gunpowder that is loaded with the alkali metal and melts and heats the alkali metal at the initial stage of the reaction is used. Since it is necessary to insert the opening, it has an opening, and the opening is of an assembling system in which it is closed by a welding flange and a flange attached by a press fitting screwed into the welding flange.

That is, as shown in FIG. 5 and FIG. 6, the outer tube and the water pipe 1a which are formed by the water pipe 1a closely wound in a spiral shape.
Concentric with the water pipe 1b spirally wound inward
The inner cylinder constituted by
Is formed. An alkali metal 3 as a fuel is loaded in the combustion chamber N inside the combustor body 2, and a plurality of preheating agents 4 are embedded in the alkali metal 3.

Inner surface of the spiral water pipe 1a of the combustion chamber N and the water pipe 1b
Cylindrical bodies 10a and 10b are welded to the outer surfaces of the cylindrical bodies 10a and 10b, respectively, and annular welding flanges 1'having a plurality of circular holes 1'a are formed on the inner and outer circumferences of the respective ends of the cylindrical bodies 10a and 10b. 7 are welded at the portions indicated by A'and B'and the plurality of holes 1'a
Thus, an opening is formed in the space between the cylindrical bodies 10a and 10b. By inserting the alkali metal 3 into the combustion chamber N through this opening and further inserting the preheating agent 4 into the hole of the alkali metal 6, these are filled and the cylindrical bodies 10a, 10b are filled.
The alkali metal is supported by.

On the other hand, an oxidizer injection nozzle 7 is previously welded to a hole of a circular flange 1 ″ having a size corresponding to the circular hole 1′a of the welding flange, and this is packed in the circular hole 1′a of the welding flange. The flange 1 ″ and the oxidizer injection nozzle 7 are attached to the combustor main body 2 by inserting it with the interposition of 6 and tightening the flange pressing metal fitting 5 which is screwed with the threaded portion provided in the circular hole 1′a.

As described above, the sealed metal combustor containing the alkali metal 3 and the preheating agent 4 is constructed.

[Problems to be Solved by the Invention]

In the above conventional metal combustor, the opening for inserting the alkali metal and the preheating agent has a structure in which it is closed by a welding flange and a flange attached by a press fitting screwed into the welding flange. When subjected to a high temperature of about 3500 ℃ generated by the reaction of, the permanent seal is generated and the sealing property is impaired. There was a problem.

Further, in the metal combustor having the above structure, it is possible to solve the above problems by welding the flange to the welding flange instead of the screw pressing method, but in this case, the filled alkali metal is melted. However, it is difficult to adopt the welding method because there is a risk of ignition of preheating agents such as gunpowder.

The present invention is intended to provide a method of manufacturing a metal combustor, which solves the problems of the conventional metal combustor described above.

[Means for Solving the Problems]

A method for manufacturing a metal combustor according to the present invention is a metal combustor in which an alkali metal as a fuel and a preheating agent arranged in the alkali metal are loaded into an annular combustion chamber to combust the alkali metal with an oxidizer. An inner cylinder and an outer cylinder having a circular cross section whose plate thickness is thinner than the base are arranged at one end of the combustion chamber, and an alkali metal and a preheating agent are loaded into the combustion chamber to insert one end of the alkali metal inside. Supported by the thin end portions of the tubular body and the outer tubular body, the oxidant injection nozzle is welded and attached to the hole of the annular flange, and the rear end portions of the inner tubular body and the outer tubular body are attached. An annular flange having the oxidizer injection nozzle welded to the entire peripheral surface is welded.

[Action]

In the present invention, the annular flanges are welded to the inner cylinder and the outer cylinder, and since the plate thicknesses of the inner cylinder and the outer cylinder around the welding point are large, diffusion of welding heat is promoted. Further, since the thickness of the portions of the inner cylinder and the outer cylinder that are in contact with the alkali metal is thin, the conduction of welding heat to the alkali metal is reduced. Therefore, the alkali metal is affected by the welding heat and the rise in the temperature is reduced.

Also, the annular flange welded to the oxidizer injection nozzle is
Since it is attached to the combustor by welding, permanent strain does not occur and problems such as leakage of alkali metal do not occur even when subjected to high temperature due to combustion of alkali metal.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

The combustor body 2 has an outer cylinder formed by water tubes 1a closely wound so as to contact each other, and an inner cylinder formed by water tubes 1b densely wound so as to contact each other concentrically with the outer cylinder. It is formed by and.

The molten alkali metal 3 in the combustor body 2 is replaced by water tubes 1a, 1b.
Inserted from the opening at the one end formed in step 1, form a vertical hole in the center with a core, etc., and after solidifying the alkali metal,
The preheating agent 4 is inserted into the same hole.

Then, the inner cylindrical body 2-1 and the outer cylindrical body 2-2 whose both ends are thinner than the base are brought into contact with the inner peripheral surface of the water pipe 1a and the outer peripheral surface of the water pipe 1b, respectively. The inner cylindrical body 2-1 and the outer cylindrical body 2-2, which are thin on the inner side, are brought into contact with and supported by one end of the alkali metal.

Next, the annular welding flange 1 to which a predetermined number of oxidizer injection nozzles 7 have been welded and attached is attached to the inner tubular body 2-1 and the outer tubular body 2.
At the rear end opening formed by -2, the entire peripheral surfaces A and B are welded to seal the combustor body 2. At this time, as shown in FIG.
-1, the base portion of the outer tubular body 2-2 and the step portion of the end portion having a thin plate thickness are brought into contact with each other, and then welding is performed.

In the present embodiment, the welding flange 1 is welded in a state of being in contact with the thick base portions of the inner tubular body 2-1 and the outer tubular body 2-2, so that the diffusion of welding heat is promoted. Further, since the alkali metal 3 is in contact with the thin plate portions at the tips of the inner tubular body 2-1 and the outer tubular body 2-2, conduction of welding heat is reduced.
As a result, the temperature rise of the alkali metal 3 is reduced, and its melting and ignition of the preheating agent 4 can be prevented.

Further, since the annular welding flange 1 to which the oxidizer injection nozzle 7 is welded is attached to the inner cylindrical body 2-1 and the outer cylindrical body 2-2 by welding, the high heat (3,500 (.Degree. C.) and the subsequent cooling do not cause a gap due to permanent set, and no failure such as leakage of alkali metal occurs.

Furthermore, since the annular welding flange 1 is welded in a circular trajectory, automatic welding is easy, and its speed can be increased to reduce welding heat.

FIG. 4 shows the result of the experimental example conducted for this example. As shown in the figure, it was confirmed that the temperature rise of the alkali metal (lithium) due to the welding of the welding flange can be suppressed to a low level.

In the above embodiment, the inner cylinder and the outer cylinder are provided with stepped portions having different plate thicknesses at the rear ends thereof, but the plate thickness of the rear part is set to be the same as that of the tip part, and An annular welding flange may be welded to the thick rear end portion.

〔The invention's effect〕

As described above, according to the present invention, it is possible to manufacture a sealed metal combustor while suppressing an increase in temperature of alkali metal, and to prevent leakage of alkali metal from the manufactured metal combustor. it can.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is an explanatory view of a metal combustor, FIG. 2 is an enlarged sectional view of a II portion of FIG. 1, and FIG. 3 is a side view thereof. FIG. 4 is a graph showing the results of an experimental example of the same embodiment, FIG. 5 is an explanatory view of a conventional metal combustor, FIG. 6 is a sectional view of a main part of the conventional metal combustor, and FIG.
The figure is a side view of the conventional metal combustor. 1 ... Welding flange, 1a, 1b ... Water pipe, 2 ... Combustor body, 2-1 ... Inner cylinder, 2-2 ... Outer cylinder, 3 ... Alkali metal, 4 ... Preheating agent, 7 ... Oxidizing agent.

Claims (1)

[Claims] 1. A metal combustion apparatus in which an alkali metal as a fuel and a preheating agent arranged in the alkali metal are loaded into an annular combustion chamber to burn the alkali metal with an oxidant, and a plate thickness of a tip portion of the metal burner is greater than that of a base portion. An inner cylinder and an outer cylinder having a thin circular cross section are arranged at one end of the combustion chamber, and an alkali metal and a preheating agent are loaded into the combustion chamber so that one end of the alkali metal becomes the inner cylinder and the outer cylinder. Supported by the thin tip of the above plate,
After attaching the oxidant injection nozzle by welding to the hole of the annular flange, weld the annular flange where the oxidant injection nozzle is welded to the entire peripheral surfaces of the rear ends of the inner cylinder and the outer cylinder. A method for manufacturing a metal combustor, comprising: