Subscribe
PLANT

Energy savings

Upgrading and increasing the capacity of Soniplastics inc.’s cooling system – its chiller and water towers – yielded sizable savings and profits, according to Robert Laroche, the director of maintenance at the Boucherville, Que. plant.


August 8, 2011
Kathy Smith

Upgrading and increasing the capacity of Soniplastics inc.’s cooling system – its chiller and water towers – yielded sizable savings and profits, according to Robert Laroche, the director of maintenance at the Boucherville, Que. plant.

“What made the business case for the project more appealing was the projected $100,000 in annual electrical savings, and sizable incentives from Natural Resources Canada and Hydro-Québec,” says François Lambert, the company’s director of finance.

Soniplastics produces polyvinyl chloride (PVC) window frames. the 14,400 square-metre facility operates 24 hours a day almost year-round, consuming about 32,000 gigajoules of electricity and 2,200 gigajoules of natural gas, so the annual energy costs before the retrofit were about $560,000.

Yves Allard, the plant’s director, explains that the previous cooling system could not keep pace with increased production. the two water chillers had capacities of 225 and 125 tonnes, and the 125-tonne chiller could serve only 13 of the 21 plastic extruders. the $488,000 project (completed in June 2009) included the installation of a high-efficiency frictionless magnetic-bearing centrifugal compressor chiller with a capacity of 300 to 325 tonnes (the 225-tonne chiller is now a back-up unit); two 270-tonne water towers with a 15 hp variable-speed drive motor that produces 550 tonnes of cooling capacity in the summer; and two new variable speed 40-hp pumps that move water between the chiller and the water towers. the cooling system is now automated and equipped with motorized valves using water for cooling from the water towers rather than the chiller, when outside temperatures fall below 15 to 18 degrees C. “this gives us not only free cooling, but also more flexibility, reliability and redundancy in the system,” says Allard.

Laroche notes that the new automated system is quieter, more reliable and designed to optimize chiller operations. he adds, “the financial benefits are clear: there is no increase in the facility’s electricity use since the upgrade, despite a 20% increase in production. that equates to about $10,000 in savings per month, more than the anticipated annual savings in electricity for the project.”

Source: Natural Resources Canada case history