Flow speed

in lines carrying water, as in cables, pipes and hoses, should not exceed 2.5 m/sec. In the crucible induction furnace coils the flow speed should be approx. 2 m/sec. In connection areas and necessary restrictions in pipes caused by the design, flow speeds of up to 4 m/sec. can sometimes occur. The lengths of line where this occurs should be kept within a maximum range of 100 mm. In extraction systems, speeds of up to approx. 40 m/sec. can be achieved in the pipelines. In a hood extraction system of a 13-t furnace, the flow speed at the extraction slot in the crucible cover should be approx. 6 m/sec., in order to cre- ate an adequate under-pressure.