Apparatus for introducing substances into liquids e.g. metal melts

A method of introducing a substance into an elevated temperature liquid, comprising:

• providing a container for containing the elevated temperature liquid;
• providing a receiving opening in the container below the level of the elevated temperature liquid;
• introducing a refractory body into the receiving opening of the container and providing the refractory body with a plurality of passages between outer and liquid-confronting ends of the body;
• adapting each of the passages in the refractory body for conveying different, selected substances to the liquid in the container;
• placing dislodgeable, refractory passage-closing means for each of the passages in the refractory body, and locating the closing means at the liquid-confronting end of the body thereby preventing liquid in the container from entering the passages;
• locating a number of elements each in a different one of the passages for displaceable movement independently of one another and arranging each element to engage with the closing means associated with the respective passage;
• providing a plurality of actuating means at the outer end of the refractory body and arranging the actuating means for selective operation to propel the corresponding movable elements toward the associated closing means thereby dislodging the closing means and opening the corresponding passage to allow feeding of a selected substance into the liquid in the container;
• arranging the actuating means to operate so that the passages are opened in a chosen order and the selected substances can be fed into the liquid in said chosen order;
• and
• feeding the selected substance along one of the passages in the refractory body and into the liquid in the container.