Effects of Frequent Blow-downs
A large industrial manufacturer called a Lakeside service provider for service of their boiler pretreatment system. Excessive water usage and high levels of scale build up on the burner tubes was causing frequent blow downs. The boiler system was using soft water for make-up causing the boiler to operate at 8-13 cycles. This excessive blow down increased water usage, pretreatment expenses and was wasting fuel and energy. High conductivity and elevated levels of bicarbonate alkalinity and silica contributed to these issues. The high levels of bicarbonate alkalinity can’t be removed by a softener system and will generate carbonic acid in the steam condensate, which is very corrosive when in contact with metals like copper and steel. The boilers integrity was being compromised and shorter life expectancy was determined requiring an immediate solution.
Lakeside’s Solution and Results
Lakeside engineers designed a 6,000 gallon per day reverse osmosis system that reduced the chemicals being used to keep the boiler clean. This resulted in a 47% savings.
The system also reduced the conductivity down to 7uS/cm, resulting in a 1% blow down rate. Boiler cycles increased from 8-13 to over 125 cycles of concentration saving 25% on natural gas fuel costs.
The rejection of the alkalinity reduced the CO2 levels there by reducing the carbonic acid in the steam condensate. This reduces corrosion of metal surfaces in the steam piping system, extends equipment life and reduces capital expenditures.