Device to inject solid material into a bath of liquid metal, and corresponding method

An injection device for injecting a discrete amount of solid material in particle, powder or granulated form, comprising:

• a melting furnace having walls defining a liquid metal retaining area,
• a first pipe having a lower end, an upper end and mounted through a lateral wall of the melting furnace wherein the lower end of the first pipe is disposed inside the furnace and configured to be above a meniscus of liquid metal contained within the liquid metal retaining area,
• a chamber configured to store the solid material and having an upper part and a lower end,
• an exit valve connecting the upper end of the first pipe to a lower end of the chamber wherein the exit valve is configured to be selectively opened for a period between about 0.2 seconds and about 0.8 seconds,
• a second pipe connecting the upper part of the chamber to introduce the solid material into the chamber,
• a third pipe connecting to the upper part of the chamber to introduce a pre-compressed fluid into the chamber,
• a fluid valve connecting the third pipe to the upper part of the chamber wherein the fluid valve is configured to be selectively opened for a period less than about 0.4 seconds, wherein by rapidly and sequentially opening the exit valve and the fluid valve, the exit valve emits an impulsive flow of the solid material into the furnace.

A method for injecting a discrete amount of solid material in particle, powder or granulated form, comprising

• mounting a first pipe through a lateral wall of a melting furnace, wherein the melting furnace has walls defining a liquid metal retaining area, the first pipe has a lower end and an upper end, the the lower end of the first pipe is disposed inside the furnace and configured to be above a meniscus of liquid metal contained within the liquid metal retaining area,
• connecting the upper end of the first pipe to a lower end of a chamber via an exit valve, wherein the chamber is configured to store the solid material and has an upper part, the exit valve is configured to be selectively opened for a period between about 0.2 seconds and about 0.8 seconds,
• connecting a second pipe to the upper part of the chamber to introduce the solid material into the chamber,
• connecting a third pipe to the upper part of the chamber to introduce a pre-compressed fluid into the chamber via a fluid valve, the fluid valve is configured to be selectively opened for a period less than about 0.4 seconds, and
• by rapidly and sequentially opening the exit valve and the fluid valve, the exit valve emits an impulsive flow of the solid material into the furnace.