SOUTHERN CALIFORNIA’S ENVIRONMENT At the Crossroads : The Air: <i> SIZING UP OUR PROBLEM SKIES </i> : SUCCESS STORY : Finding a Way to Beat a Problem
General Dynamics in Pomona has come up with a new air pollution control system that not only reduces emissions but is more efficient. Custom-designed for spray-paint operations, the system proves that not all controls need be cumbersome or more costly.
The company developed the system because it had a problem: The division builds ship-to-air missiles and Phalanx guns for the Navy, but without new air pollution controls the firm could not expand production.
Under its old system, it was fast approaching the limits imposed by the South Coast Air Quality Management District on emissions of volatile organic compounds (VOCs), a key ingredient of smog.
The weapons produced by General Dynamics must be coated with a paint that will stand up to the elements at sea. Such paints are high in VOCs.
Each of the several emission control systems available to solve the problem cost about $1.2 million to install. Each would have reduced VOC emissions by as much as 95%.
The company opted for a system called an “ultraviolet oxidation air scrubber,” a state-of-the-art technique that had several advantages.
First, it was far less expensive to operate than the alternatives. The scrubber costs only $12.50 an hour to run compared to $55 to $100 an hour for control technologies such as incinerators and afterburners. Secondly, the scrubber produced little or no polluting byproducts--contaminated water and emissions of carbon monoxide and oxides of nitrogen--common to other technologies.
With the new scrubber technology, fumes and spray from the painting operation are channeled through a round six-foot duct directly to a chamber outside the building. There, the paint fumes are pre-treated with ozone gas generated by high-intensity ultraviolet light and then injected into the bottom of a larger chamber. As they rise to the top through a lattice work of plastic packing material, they are sprayed from above by ozone-treated water. Finally, the gases pass through a carbon filter and are vented into the atmosphere.
With the controls, emissions of the smog-producing VOCs are held to half a ton a year, compared to 12 tons a year without the controls.
“It allows us to increase the painting capacity by 75% to 100%,” said John Aubert, environmental resources manager at the plant.
The AQMD, which enforces air quality laws in Los Angeles, Orange, Riverside and San Bernardino counties, was so impressed with the system that it presented General Dynamics with one of its first clean air awards last May.
