The incoming spring water at a bottled water plant in North America was colder than the air in the facility, leading to condensation on the bottles, which caused periodic quality problems and weakened the shipping containers. Replacing the gas-fired boilers that had been used to pre-heat the spring water with recovered thermal energy from elsewhere in the facility saved hundreds of thousands of dollars, paying for itself in less than four years.
FREE TEMPERING: COOLING TOWER WATER REPLACES NATURAL GAS
The facility was spending more than $200,000 per year to temper incoming spring water. Meanwhile, process chillers and air compressors in the plant were producing significant waste heat. We quickly determined that there was more than enough excess thermal energy available to accomplish the tempering. We then designed a system to pump the hot cooling tower water through sanitary heat exchangers and back to the towers. Controls and integrity checks were built into the system to provide monitor and adjust the spring water discharge temperature and ensure no cross-contamination occurred. The old gas-fired boilers were then turned off, saving approximately 18,000 MMBTUs per year. In a year where the plant’s spring water production increased by 8%, they still lowered natural gas usage by 39% over the previous year.