China Steel Corporation (CSC) have four blast furnaces on their main site in Kaohsiung, producing a total of 24,000 tonnes of iron per day. Each furnace requires re-lining approximately every 10-15 years, involving the complete replacement of the furnace line. In 2005 CSC re-lined blast furnace two with a new 12m diameter furnace line with an increased production capacity of 8,000 tonnes per day. DLT were heavy lift sub-contractor and construction consultant to CSC for the installation of the new furnace line weighing 3115 tonnes, which was delivered to the slag pit in eight segments weighing up to 477 tonnes each.
Each segment was delivered by self propelled modular trailers onto two lifting beams in the slag pit, which were then lifted 14m up to skid track level using 8 No DL-C125 climbing jacks. After lifting each segment was skidded 98m into the furnace house through a temporary opening created in the side of the building, as shown below.
Once inside the furnace house each segment
was lifted and aligned for welding using strand jacks located on two levels
as shown below. Eight DL-S185 strand jacks were used at the lower level
and eight DL-S418 strand jacks at high level. DL-S418 strand jacks were pooled into three groups to give a stable distribution of load between the jacks during the lift of the very stiff blast furnace, all monitored and automatically
synchronised using our DL-P40 computer control system.
Computer control and pooling was critical to the success of these operations, to keep
the loads evenly balanced between the ring of eight jacks at each level
and to be able to finely adjust the welding gaps between segments to between
1-3mm all around the joint.
All eight segments were lifted, skidded and aligned
for welding in a period of 24 days, from lifting of the first segment to
final positioning of the last segment in the furnace house - requiring a
total of 34 seperate lifting and skidding operations. This was achieved
through 24 hour working and close co-ordination with the other sub-contractors.
The total furnace shutdown period was 94 days.
A DLT produced 3D model of
the furnace line installation sequence was used to to brief all parties
and to assist in the understanding and co-ordination of this complex project..