The Cold zone (water jacket and piping) on Furnace 3 needed replacing due to wear and age. The cold zone water jacket is a 24m section of steel fabricated tubular section 2.8m wide and .9m high with a steel belt conveyor running through it.
In 1992 Furnace 1 Cold zone was changed by a local contractor. The duration to remove the existing and install the new was 14 days. The contractor at the time had removed the roof sections covering the cold zone and used a 250T crane to lift the cold zone in three sections. Installation of the new cold zone was done with the same system. The output tonnage of the plant at that time was approximately 5t p/hr or 120t per 24hr. Total tonnage loss for the plant during the outage was approximately 1680 tonnes.
In 2011 an NKW Maintenance contractor was requested to table a proposal to change the Cold zone on Furnace 3 which is the same as Furnace 1 completed in 1992. The Maintenance contractor had tabled a schedule for a duration of 21 days. The total tonnage loss for this duration would be approximately 4200 tonnes based on 200t per 24hr.
GRS was engaged on planning, scheduling and project management using the local Maintenance contractor direct for labour supply. GRS had planned and scheduled the removal and installation of the new cold zone for a duration of 7 days, total tonnage loss was approximately 1400 tonnes based on 200t per 24hr. The execution was completed utilizing a custom made rail system to slide the entire cold zone out leaving the entire building intact.
The total tonnage saving was approximately 2800 tonnes brought about by GRS’s innovative methodology and execution plan.