Soaking of Iron:

After the furnace has been completely charged it is so maintained for around 45 minutes. The charge gets gradually heated as the air blast is kept shut throughout this time. This causes the iron to acquire soaked.

Opening of Air Blast 

At the ending of the soaking period the air blast is opened up. The tapping hole is kept closed through a plug called the bot till the time the metal gets molten and sufficient metal has accumulated. Like the melting proceeds the contents of the charge move steadily downwards. The charge should therefore be replenished and the furnace be kept filled upto the charging door during the entire operation.