Post-tensioned floors were constructed in all of the warehouses as most of the movement joints can be eliminated . The stressed cables compress the concrete which eliminates shrinkage cracks . This allows for much bigger panels without movement joints . The largest jointless floor was 222m x 213m which was constructed in the Dry Goods warehouse . Detailing and design is critical for these types of floors as the floor should be allowed to shrink without getting hooked on columns or walls .
Steel fibres and conventional reinforcement were used to construct a portion of the RRU warehouse floor . A crate washer was installed on this portion of the floor and drainage channels would be difficult if posttensioned cables were used . The engineer decided to rather use fibre and conventional reinforcement . The floor was designed and constructed to slide above the drainage channels which made it possible to construct a jointless fibre reinforced floor of 67.5m x 32m .
All warehouse floors are 180mm thick , constructed with 35MPa concrete and cast to FM2 tolerances . Floors were designed for 11 ton rack leg loads and the floors can span across a 5m sinkhole . Cosinus type joints were installed at all movement joints to ensure effective transfer of wheel loads when joints open .
MECHANICAL ENGINEERING The ammonia plant is a 7.2MW installed refrigeration plant with a total of 9.2MW of heat rejection to the evaporative condensers . The plant is divided in to two suction regimes namely , -8.75 ° C and + 3.25 ° C , to optimise energy efficiency . The -8.75 ° C system is a 4.5MW chilled glycol system supplying the 2 ° C rooms with cooling , while the + 3.25 ° C system is a 2.15MW plant supplying the 14 ° C and choc box rooms with cooling . The additional high stage capacity is utilised to economise the medium ( -8.75 ° C ) plant by means of open flash economising in the high stage vessel .
A liquid sub cooler is installed on the high pressure liquid feed to the MT vessel to reduce flash gas and utilise incoming / top up condenser water to sub cool the HPL before entering the MT vessel / flash economiser . The heat required to defrost the 2 ° C coils is recovered from the discharge side of the system by means of two 200 kW condensing PHE ’ s installed in the condenser yard . This heats the warmer glycol defrost circuit from 8 ° C to 15 ° C to facilitate the defrosting of the coils in the field with waste heat from the refrigeration plant .
High quality heat is recovered from the oil systems on the screw compressors . The waste heat recovery
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