Reducing Operating Costs by Using Air-to-Water Heat Exchanger

A pharmaceutical company was planning to transfer a 5,000 SCFM oxidizer to another facility across the United States. However, when compared to the original design conditions at the present facility, the new location had different destruction efficiency rate and heat recovery expectation.

System Evaluation

A field service engineer from Anguil visited the site to examine the unit. A report was produced which included details of the existing condition of the oxidizer at its present location along with a written procedure for the appropriate disassembly and reassembly of the unit. Following the evaluation of the unit, the service engineer recommended the changes required to make the unit operate with the preferred destruction efficiency rate and energy recovery requirements.

System Upgrade

Based on the comprehensive site inspection report, Anguil worked closely with the customer to change and upgrade the system. The work included a new hot gas bypass damper and a control package upgrade.

In order to address the new facility's energy recovery requirements, a new economizer was set up between the exhaust stack and the catalytic oxidizer to transfer heat to water. The stack’s exhaust heat was transferred to the Anguil economizer, which in turn produced hot water. This lost energy is captured and can be utilized in different applications such as process water, glycol, cold makeup water, boiler feedwater, and thermal fluids.

Anguil’s air-to-water heat exchanger is made of stainless steel and has a tube and fin design with access doors for checking and cleaning the tubes. The exhaust flow from the oxidizer is 5,400 SCFM and the temperature is 450°F. Approximately 160 GPM of water is heated to 140°F using the Anguil economizer. The overall energy recovered is 1.43 MM BTU per hour with an estimated hourly savings of $14.35 per hour and yearly savings of $120,512 per year. Figures 1 and 2 show the projected and reported values with and without the energy recovery system, respectively.

Figure 1. Reported values without energy recovery system

Figure 2. Projected values with energy recovery system

Conclusion

Anguil’s air-to-water heat exchanger helped in reducing the operating costs at the new facility. In addition, the system upgrade which included a new hot gas bypass damper, control package, and economizer helped in saving significant costs.

This information has been sourced, reviewed and adapted from materials provided by Anguil Environmental Systems.

For more information on this source, please visit Anguil Environmental Systems.