OPEN HEARTH FURNACE

                                           OPEN HEARTH FURNACE

  

  

   Ø  THE FURNACE USED IN THIS PROCESS RESSEMBLES THE REVERBERATORY                   FURNACE

   Ø  PIG IRON IS MELTED IN THE FURNACE AND LARGE QUANTITY OF SCRAP IRON OR       STEEL IS DISSOLVED  IN THE LIQUID BATH    

   Ø  THE SOURCE  OF HEAT IS HEATED AIR AND COAL GAS

   Ø  IN THIS FURNACE A GREAT  ECONOMY IS OBTAINED BY THE UTILIZATION OF           THE HEAT OF THE HOT GASES OF COMBUSTION

   Ø  THESE GASES ARE MADE TO PASS THROUGH BRICK GRATINGS OF TWO                             REGENRATORS BEFORE LEAVING THE CHIMNEY

   Ø  THE AIR AND GAS ON THE OTHER HAND TRANSVERSE THROUGH TWO OTHER              CHAMBERS AFTER AN HOUR FLOW IS REVERSED

   Ø  THE INTENSE HEAT PRODUCE BY BURNING OF AIR AND COAL GAS KEEPS THE               CHARGE IN THE MOLTEN CONDITION

   Ø  SILICON GETS CONVERTED INTO SILICATES AND IS REMOVED AS A SLAG AND                CARBON BURNS TO CARBON DIOXIDE LEAVING PURE IRON   

   Ø  A  MEASURE QUANTITY OF FERROMAGNESE OR SUITABLE ALLOY IS ADDED  TO          SUPPLY  THE NECESSARY CARBON , MANGANESE,CHROMIUM,NICKEL

   Ø  THE LIQUID STEEL FINALLY IS POURED INTO THE MOULDS THROUGH LADLES

   Ø  THE FURNACE LINING MAY BE BASIC OR ACIDIC DEPENDING UPON THE FACT       WHETHER PHOSPHOROUS PRESENT OR ABSENT IN THE PIG IRON

   Ø  ACID LINING COMPRICES OF EITHER SILICA OR GANISTER (83%QUARTZ 13%CLAY     4%MOISTURE AND OTHER IMPURTIES

   Ø  BASIC LINING IS USUALLY MAGNISITE (MgCO3) OR DOLOMITE (CaCO3.MgCO3)