Port Kembla Copper needed to reduce an excessive amount of acid being carried with gases out of the cooling tower into mist collectors. There was more acid than the collectors could cope with and they were overflowing.
The spray droplet size was too fine.
Cooling spray discharge at the top of the tower was being carried off in the gas stream instead of falling to the bottom of the tower.
An engineer from Tecpro Australia examined the tower. It was immediately obvious to him that the spray nozzles fitted to the tower were the incorrect type for the application. They had a design characteristic of producing fine droplets.
The desired minimum droplet size required to prevent carry over to the mist collectors was 1mm. Tecpro Australia recommended special acid resistant nozzles that would generate droplets larger than the required 1mm diameter at the operating pressure and flow rate.
The recommended nozzles were larger than the existing nozzles, and so a straight change over was not possible. Tecpro Australia designed and had manufactured special flanged adaptors so that the new nozzles could be easily retrofitted in place of the existing nozzles.
The larger droplets produced solved the carry-over problem.
Posted on 07-May-2015