FI101014B - Method and apparatus for smelting light metals, especially magnesium - Google Patents

Description

1 101014 Method and apparatus for melting light metals, especially magnesium.

When melting light metals, especially magnesium, a precise dosage of the metal melt is necessary. Pumping of molten from a furnace to a casting site is known in the past, for example with the help of S with the help of complicated pressure and vacuum systems. Another known way is to pump the melt via a separate dosing container, where the level hills are constantly so that excess melt flows back into the furnace via a separate return line. Since the distance between the furnace and the dispenser can be long, i.e. several meters, this also becomes an expensive solution.

In contrast, our invention, which is described below, provides a safe and economical solution to the problem. The essential features of our invention are set forth in claims 1-3.

The furnace according to our invention, Fig. 1, has an inlet chamber 1, a main melting chamber 2 and an outlet chamber 3.1 between the walls 4 and S between the openings 6 and 7 of the chambers close to the bottom, through which the fully or partially molten metal can flow. As the metal melt flows from chamber to chamber, a successive purification thereof occurs, especially if a filter 8 is placed in a partition wall. The pollutants are removed if necessary. The oven heating is not shown here.

Melted magnesium can be measured in the molding machines manually or with an automatic bucket, the outlet chamber lid being lifted off.

A preferred method, however, is to transmit melt by means of a pneumatic pump system as schematically shown in Fig. 2.1. with the lid 12.

When overpressure via a pipe 13 in the pump cover, according to one of us previously patented processes, is applied to the metal surface of the pump chamber by means of a suitable surface, e.g.

30, the molten metal is pushed out through the outlet pipe.

The outlet pipe opens into the upper part of a container, which may be a separate chamber in the furnace or a completely separate small dose furnace 14. The lower inner surface 15 of this pipe must be slightly higher than the maximum level of the metal melt in the furnace. lower than the dose oven and the The upper edge 16 of the chamber means that the amount of melt that a pump stroke pumps out is accommodated without the dose oven becoming overcrowded. The amount of melt per pump type 5 can be calculated approximately and determined experimentally.

When the overpressure at the end of the pump stroke ceases, excess melt flows through the same pipe back to the pump chamber, i.e. the level control in the dose oven is automatic even though the pump is operating continuously, with the exception of the cool, controllable breaks between each pump stroke.

In the bottom of the dispenser there is a valve 17 which is opened in a signal from the casting machine. A clock regulates the time this valve is open. Since the level in the dose furnace is almost constant, an exact dosage is obtained. If the valve is computer controlled, the dose rate can also be varied.

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Claims (4)

A method for melting light metals, in particular magnesium, comprising a melting furnace divided into two or more chambers, wherein the metal melt and the solid metal fed to the furnace pass from the feed chamber (1) through openings (6; 7) in the main smelting chamber (2) and furnace partitions (4; S) to the discharge chamber (3), from which the metal melt is pumped by means of a pneumatic pump chamber (9) in this chamber through this obliquely upward discharge pipe (11) to a separate dosing chamber or dosing furnace (14) and further through a bottom valve (17) for consumption, characterized in ) The metal flow to the dosing furnace due to the prevailing intermittent overpressure does not lead to overfilling, but to the excess metal flowing back into the pump chamber through the same pipe (11) when the overpressure ceases after each pump stroke, leaving the molten metal in the dosing furnace constant. Apparatus for carrying out the method according to claim 1, comprising a melting furnace divided into two or more chambers, wherein the metal melt and the solid metal fed to the furnace pass from the feed chamber (1) through the main smelting chamber (2) and openings (6; 7) in the furnace partitions (4; 5) (3), from which the metal melt is pumped by means of a pneumatic pump chamber (9) in this chamber through this obliquely upwards outlet pipe (11) to a separate dosing chamber or dosing furnace (14) and further through a bottom valve (17) for consumption, characterized in that the pump chamber (17) 9) the obliquely directed outlet pipe (11) also acts as a return channel for excess metal, so that when the overpressure ceases after each pump stroke, the excess metal flows back into the pump chamber without overfilling the dosing chamber (14), keeping the molten metal in the dosing chamber constant. Device for carrying out the method according to claim 1, characterized in that the lower inner surface (15) of the inclined upward discharge pipe (11) of the pneumatic pump chamber (9) in the discharge chamber (3) is slightly higher than the surface of the molten metal 30 in the discharge chamber. below the upper edge (16) that the amount of metal caused by one pump stroke does not lead to overfilling of the dosing furnace (14).