Lance
Oxygen gas is supplied through a water cooled lance, the tip of which fitted with multi-hole Laval nozzles made of copper
| Figure 11.3: |
Lance to blow oxygen |
Lance is nearly 8-10m long and its diameter varies between 20cm to 25cm depending on the furnace capacity. Water requirements are around  at a pressure of . Lance movement is controlled by electrically operated gear system.
Lance life is determined by the life of the nozzles. Failures of the lance may be due to faulty cooling, manufacturing defects and differential expansion between copper tip and steel tube.
The most important part of the lance is the Laval nozzle. Functions of the nozzle are
- Supply and distribution of oxygen
- To produce a gaseous jet
- To induce bath agitation,
- To produce droplets
Lance is designed to produce non-coalescing free oxygen get. The lance is designed to operate at an upstream pressure of 10- 12 bar.
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