JPS5920740B2 - Cold trap for liquid metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a cold tomb for removing impurities from liquid metal.

For example, sodium, which is a liquid metal, is used as a coolant in nuclear reactors, especially in the primary cooling system of fast breeder reactors.

By the way, impurities contained in this liquid metal have undesirable effects such as corrosion of equipment, so a cold trap is provided in the circulation path of this liquid metal to remove impurities.

FIG. 1 is a cross-sectional view showing the configuration of an example of a conventional device of this type. In the figure, 1 is a liquid metal inlet, 2 is an annular cooling section, and 3 and 4 are the upper and lower ends of this cold trap, respectively. A plate 5 is a refrigerant flow-through section provided on the outer periphery of the cooling section 2 through which a refrigerant such as nitrogen gas for cooling the liquid metal flows, 6 is a refrigerant inlet, 7 is a refrigerant outlet, and 8 is a refrigerant flow-through section between the cooling section 2 and the refrigerant flow-through section 5.
A cylindrical wall between the cooling section 2 and the trapping section 9 is provided at the upper center of the cooling section 2 to capture precipitated impurities.
11 is a capture part 9 inside the partition wall 10.
A metal mesh 12 is an outlet for taking out the refined liquid metal through the cooling section 2 and the capturing section 9.

The liquid metal that enters the cooling section 2 from the liquid metal inlet 1 is cooled by a refrigerant such as nitrogen gas that enters the refrigerant flow section 5 from the refrigerant inlet 6 and flows out to the refrigerant outflow lower, and precipitates impurities in the capture section 9. Refined.

This purified liquid metal is taken out from the takeout port 12.

However, in a cold trap with such a structure, since the fluid metal flows only from below the capture part 9, only the lower metal mesh becomes clogged, and the capture part becomes blocked without being able to effectively utilize the upper metal mesh. In many cases, the capture capacity was small and cold traps had to be replaced in a short period of time.

This invention was made in view of the above points, and an object of the present invention is to provide a cold trap with a large trapping capacity that can effectively utilize the metal mesh in the trapping section by adding ingenuity to the flow path of the trapping section. It is.

FIG. 2 is a cross-sectional view showing the structure of an embodiment of the present invention. In the figure, 13 is a cylinder extending from the lower end of the capture part 9 into the inside thereof and is not loaded with a metal mesh, and 14 is a cylinder 13 of the cylinder 13. A through hole 15 provided in the wall surface is a liquid metal flow path within the cylinder body 13.

A metal net 11 similar to that of the conventional device is loaded in the outer circumferential space of the cylinder 13 in the capture section 9 and in a portion above the upper end surface of the cylinder 13.

In this embodiment, the liquid metal that enters the cooling section 2 from the liquid metal inlet 1 is cooled by a refrigerant such as nitrogen gas that enters the refrigerant flow section 5 from the refrigerant inlet 6 and flows out to the refrigerant outflow lower. Enter.

At this time, a portion directly enters the metal net 11 from the lower end of the capture section 9, but the remainder passes through the fluid metal channel 15 in the cylinder 13, enters the capture section 9 through the through hole 14, and precipitates impurities. It is purified and taken out from the takeout port 12.

As can be seen from the above operation, in this embodiment device, the capture section 9
In this case, the metal net 11 is effectively utilized not only at its lower end but also over the entire area, so that the trapping capacity can be sufficiently increased.

Although the above embodiment shows a case in which no metal net is loaded into the cylinder 13, this is not necessary; for example, a smaller amount may be loaded, and in this way, the liquid metal can be The flow distribution can also be made appropriate.

NaojuAs described in detail, in this invention, the liquid metal is purified by cooling the liquid metal and bringing the cooled liquid metal into contact with the metal mesh layer loaded in the trapping section to precipitate and capture impurities. In the trap, a plurality of liquid metal flow channels extending from the inflow end to the trapping part to the middle of the thickness direction in the metal net have passage holes for the liquid metal on the wall surface, and are not filled with the metal net. Since the cylindrical body was provided,
The metal mesh in the trapping section can be effectively used without clogging due to impurities only at the inlet end, and a cold trap with a large impurity capture capacity can be obtained.Moreover, by using a cylindrical shape, loading of the metal mesh is easier. The work becomes easier, and since a plurality of cylinders are provided, the speed of capturing impurities becomes faster.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of an example of a conventional device, and FIG. 2 is a sectional view showing the structure of an embodiment of the present invention. In the figure, 1 is a liquid metal inlet, 2 is a cooling section, 9 is a capture section, 11 is a metal mesh, 13 is a cylinder, 14 is a through hole, and 15 is a cylindrical liquid metal channel. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A cooling part that cools the liquid metal flowing in from the liquid metal inlet, a trapping part in which a metal net is loaded and precipitating and capturing impurities in the liquid metal cooled by the cooling part, and an inflow end to this trapping part. A cold for liquid metal comprising a plurality of cylindrical bodies for liquid metal channels extending from the metal net to the middle of the thickness direction thereof and having passage holes for the liquid metal on the wall surface thereof, and not filled with the metal net. trap.