Amount of liquid metal which can be molten by the melting furnace within a specified time. The melting rate is usually indicated in tons/hour.
The melting rate of cupola furnaces is mainly a function of coke and blast rate with coke quality and fragmented size to be considered as constant.
The simplified illustration of the processes in the furnace makes understanding easy. Iron of the next charge can only get into the melting zone if the coke from the previous charge is burnt. The lower the cokecharge and the higher the blast rate, the quicker this happens. Thus the melting rate increases with increased blast rate at constant cokecharge as well as with constant blast rate at reduced cokecharge. If one of these factors is changed to the contrary, the melting rate decreases.
At a constant cokecharge, blast rate and melting rate are in a linear relation with each other. Even E. Piwowarsky and K. Krämer noticed that the same melting rates correspond to the temperature maximum achievable by the reduction of the blast rate at different cokecharge rates.
Cupola furnace network diagram