AEROSPACE COMPANY CONVERTS TO WATER-BASED CLEANERS
Reduces Costs in Vapor Degreaser Conversion
Hydro-Aire is a division of Crane located in Burbank, California. The company has 572 employees. Hydro-Aire manufactures braking systems, pumps and air locking devices and is a Boeing subcontractor. Hydro-Aire also repairs the pumps used in military and commercial aircraft like the C-17 and the C-130 transport.
IRTA began work with Hydro-Aire in 1997 to assist the company in converting away from solvents in a variety of applications. An earlier article in the Spring 1998 Alternative described the company's conversion away from 1,1,1-trichloroethane (TCA) in a printed circuit board assembly process. This article focuses on Hydro-Aire's conversion away from TCA in vapor degreasing and mineral spirits in batch loaded cold cleaning.
For many years, Hydro-Aire used TCA in four vapor degreasers for cleaning parts in three areas of the plant including the deburring area, the hone, lap and grind area and the non-destructive testing area. Production of TCA was banned worldwide in January, 1996 because the chemical contributes to stratospheric ozone depletion. Although inventories are still available, the chemical, at this stage, is very expensive. IRTA began working with Hydro-Aire to identify an alternative water-based cleaning process that would be suitable for cleaning the company's parts. "We needed a cost effective alternative and one that would be better for the workers and the environment," says Tommy Jennings, Environmental Manager at Hydro-Aire.
Hydro-Aire's parts are made of many materials including stainless steel, aluminum, steel and titanium. Laboratory testing identified water-based cleaners that would be suitable for cleaning the range of contaminants that must be removed from the parts. Extensive field testing revealed that an ultrasonic system would be required for the cleaning because Hydro-Aire's parts had many passages, blind holes and crevices. After considerable evaluation of various types of systems, the company decided to purchase three ultrasonic cleaning systems from Western Sonics. These systems each have a wash bath, two rinse baths and a hot forced air dryer. The wash and two rinse baths contain ultrasonics. All three systems are automated with a robot that transfers the baskets from station to station.
Two of the ultrasonic systems have been installed and are up and operating in the deburring area and the hone, lap and grind area. The third system is scheduled for installation shortly. In all three systems, a rust inhibitor is used to supply a protective coating for the ferrous metal parts in the first rinse. Deionized water is used in the second rinse and these rinses are routed to a closed loop water recycling system which removes the soils and returns clean water to the system. "We programmed the systems to go through a particular sequence, depending on the type of part being cleaned and the cycle that's required," says Jon Zavadil from Western Sonics.
The water-based cleaners that are being used in the ultrasonic systems are made by W.R. Grace and are supplied to Hydro-Aire by Applied Cleaning Technologies (ACT). "The new cleaners are environmentally friendly and they do a very good job on the parts," says Mike Halbert of ACT.
IRTA also worked with Hydro-Aire to find an alternative to three batch loaded cold cleaning units that used mineral spirits. South Coast Air Quality Management District (SCAQMD) Rule 1122 "Solvent Degreasers" requires batch loaded cold cleaners to use solvents with a VOC content of 50 grams per liter or less or to be replaced with an airless/airtight degreaser by January 1, 1999. Airless/airtight degreasers are very expensive and it would not have been practical to use this option in Hydro-Aire's machine shop.
IRTA arranged for Hydro-Aire to test water-based sink-on-a-drum units as replacements for the batch loaded cold cleaners. The company purchased three of these systems from ACT. The cleaner used in the systems, also supplied by ACT, is a neutral chemistry which does not damage the workers' hands.
"We're very happy with the new water-based cleaning systems," says Mr. Jennings who engineered and worked very hard on the conversions. "When we used the vapor degreasers, our annual costs were close to $200,000. Even though Hydro-Aire had to purchase the ultrasonic systems, our costs have been reduced to about $70,000 per year." We improved the cleaning operations for the workers and the environment and we also saved a lot of money."
|
|
||
|
TCA Vapor Degreasing |
|
|
| Annualized Equipment Cost |
|
|
| Cleaner Cost |
|
|
| Maintenance Cost |
|
|
| Labor Cost |
|
|
| Disposal Cost |
|
|
| Electrical Cost |
|
|
| Regulatory Fees |
|
|
| Total |
|
|