Method and apparatus for rapid high temperature ladle preheating

An apparatus for preheating of ladles, which comprises:

• a refractory lined wall including a ring portion extending forward from the base of said wall and sized to meet the rim of the ladle;
• a burner extending through said wall, within the circumference formed by said ring, for directing a flame into the ladle interior;
• an exhaust channel for evacuating the flue gases from within the ladle when it is being heated;
• a fuel valve means for controlling the fuel flow being delivered through said burner;
• air valve means for controlling the combustion air being delivered through said burner;
• oxygen valve for controlling the oxygen flow being delivered through said burner;
• control means for measuring the hot face ladle lining temperature and for communicating with said fuel, air and oxygen valve means to control the heat input of said burner and flame monitoring the instant flows of fuel, air and oxygen, and maintaining the ratio of fuel to total oxidizer close to stoichiometric and to adjust the ratio of air to oxygen based on said temperature.

A method of a rapid ladle preheating comprising the steps of:

• substantially enclosing and sealing the open end of a ladle with refractory material;
• providing an opening in said refractory material enclosure sufficient to receive within said opening protrusions caused by material buildup on one sector of said ladle;
• generating a flame and directing it into the interior of said ladle;
• exhausting the combustion products of said flame through an exhaust port in said ladle heater located adjacent to said opening in said refractory material;
• and
• exhausting, with said combustion products, ambient air which infiltrates into said ladle interior through said opening.

A fuel supply and control system for supplying fuel, air and oxygen to a burner which provides the flame for a ladle heater and for adjusting the temperature of the burner flame, which comprises:

• means for supplying air to said burner;
• means for continuous control of said air supply means;
• first means for supplying fuel to said burner in about stoichiometric proportion to air supplied by said air supply means;
• at least one auxillary means for supplying oxygen to said burner, comprising a flow valve which determines the amount of oxygen which will be supplied by said oxygen supply means and a controllable solenoid valve for opening and closing said supply means;
• at least one auxiliary means for supplying fuel to said burner, each of said auxiliary fuel supply means associated on a one-to-one basis with each of said auxiliary oxygen supply means, comprising a flow valve which determines the amount of fuel which will be supplied by said auxiliary file supply means and a controllable solenoid valve for opening and closing said auxiliary fuel supply means, wherein the flow valve of each auxiliary means for supplying fuel provide a fuel flow which is about stoichiometric with the oxygen flow allowed by the flow valve of the associated means for supplying oxygen;
• and
• means for controlling the solenoid valves for each associated pair of auxiliary fuel supply means and auxiliary oxygen supply means such that said solenoid valves for each such pair are either both open or both closed at the same time and that said fuel supply and control system can vary the level of oxygen participation on a stepwise basis while always keeping the ratio of fuel to oxidizer about stoichometric by opening or closing the associated pairs of auxiliary fuel and oxygen supply means.