Foundry Coke: Non-recovery Coke Production

What is Non-Recovery Coke Production ? Different with by-product coke plants, Non-recovery Coke Plants are originally referred to as Beehive Ovens, the coal is carbonized in large oven chambers. The carbonization process takes place from the top by radiant heat transfer and from the bottom by conduction of heat through the sole floor. Primary air for combustion is introduced into the oven chamber through several ports  located above the charge level in both pusher and coke side doors of the oven. Partially combusted gases exit the top chamber through "down comer" passages in the oven wall and enter the sole flue,                             
Thereby heating the sole of the oven. Combusted gases collect in a common tunnel and exit via a stack which creates a natural draft in the oven. Since the by-products are not recovered, the process is called Non-Recovery cokemaking. In one case, the waste gas exits into a waste heat recovery boiler which converts the excess heat into steam for power generation. Chinese foundry coke is mostly produced from Beehive Ovens.