Article: Reducing Cooling Tower Operating Costs

By James McDonald, PE, CWT

A midwestern industrial plant had a problem. The plant had a cooling tower that supplies cooling water to air compressors, oil coolers, air dryers, and various process equipment. The local city water and sewer rates were increasing significantly and their molybdate-based chemical treatment costs were skyrocketing as molybdate costs had risen nearly 1,000% lately! In an effort to cut operating costs, the plant looked for ways to decrease their cooling tower makeup water, sewer, and chemical requirements. Various ideas were investigated such as:

• Improved blowdown controller
• Fixing leaks
• Acid feed
• Soft water makeup
• Blended city/soft water makeup
• Water treatment chemistry
• Recycled wastewater