The Recovery Bottom Blowing Process
Bottom blowing is a metallurgical process that is adapted to various steelmaking applications in order to improve overall production efficiency. The process involves blowing oxygen through the bottom of the furnace, just above the surface of the molten material, rather than through the top of the furnace.
When the process is used in steelmaking, it is known as “recovery bottom blowing”. This is because the oxygen helps to dislodge impurities that have settled at the bottom of the furnace during the steelmaking process. These impurities can include slag, sludge and other contaminants that reduce the quality of the finished steel. By removing these impurities, it allows for cleaner, more efficient steel production.
Bottom blowing can also be used in other applications, such as during the production of castings, to reduce the amount of time required to heat the material. In this case, the oxygen helps to raise the temperature of the material more quickly, making production more efficient.
The recovery bottom blowing process is relatively straightforward. It begins with the furnace being heated to the proper temperature for steel making. Once the furnace is heated, a stream of oxygen is introduced at the bottom of the furnace at a rate of about 80 meters (262 feet) per minute. The oxygen is then directed toward the liquid surface using a special nozzle, producing a high-velocity, concentrated stream of oxygen bubbles.
As the bubble stream makes contact with the liquid surface, it begins to dissolve the impurities, which are then drawn into the bubbles and removed from the surface. As this process continues, production becomes more efficient and the quality of steel produced is improved.
The oxygen bubbles created during the process also help to agitate the surface of the molten material, creating a more uniform temperature throughout the furnace. This improves productivity and reduces the time required to bring the material to the proper temperature, thereby making the entire process faster and more efficient.
The recovery bottom blowing process can be used in virtually any kind of steelmaking production line. It is especially useful in creating high-quality steels that require very low levels of impurities. Additionally, the improvements in production efficiency afforded by the bottom blowing process can lead to significant cost savings over the life of the production line.
