THE IMPORTANCE OF GOOD HEAT EXCHANGE
A site where the Cooling Tower’s water was in a horrendous state due to a Total Dissolved Solids Controller being so out of kilter, it never carried out Water Dumps for months to keep the Dissolved Solids levels low. We attended site to High Pressure trips where we found almost no heat being transferred in the Condenser Plate Heat Exchanger. We initially carried out an acid flush but the heat exchange was still very poor. We ultimately condemned the Condenser under large protests from the site agent. When we changed the plate, the old plate weighed some 18 KG Heavier than the new one. We installed and commissioned the new plate and the screw compressors head pressure went from the previously seen 26 BarG down to 16.5 BarG on R407C. These reduced pressures return logarithmic running cost savings, the works paid for themselves within several months.
Another site had a Shell & Tube Condenser, again Discharge Pressure Unloading was seen on the compressors, again zero heat transfer was happening in the condenser. We removed the end plates and rodded the tube bundle. Over half the tubes were totally blocked making an acid flush useless. We re-assembled the condenser and recommissioned, again seeing the revigorated condenser heat exchanger delivering excellent cost savings.
