BD is meant to keep a reasonable solids' concentration due to evaporation, cycle after cycle, of the circulating cooling water (ccw) in the CT.
The ROT value for evaporation losses is 1% of the ccw rate for each 10 deg F in cooling range. Thus BD, as % ccw, is estimated at
0.1(delta t, deg F)/(C-1)
where C is cycles of concentration, or the ratio
"solids in ccw/solids in makeup water".
How can a chemical addition keep solids' concentration constant w/o makeup water? Is your chemist chelating the solids or precipitating them ? Please let me know of your chemist's revolutionary trick. By the way makeup is used to also compensate for windage and carryover losses.
Thanks for your feedback. There is no end to learning.