January/February 2012 A directed air flow system requires approxi- mately 40-60% as much air as a conventional ventilation system. Because less air is required, the system demands less equipment, operating costs, and maintenance and therefore typically costs less than conventional systems.
Dust control for trimming, grinding A dust control system for trimming and grind- ing operations can greatly improve the working conditions while containing dust that could affect nearby parts. A state-of-the-art dust con- trol system transports fiberglass particles away from the worker and collects it for proper dis- posal. The system then re-circulates clean air back to the work area.
Structural Composite Technologies operates two grinding booths to accommodate its two main lines. The company produces large fabri- cations such as vessels, stacks, tanks, and other process equipment, along with a commodity line for bathtubs and shower enclosures.
The company’s large grinding booth was designed to hold very large parts – products that often require a bridge crane. As a result, the room was essentially a 4-wall chamber with no roof – a unique requirement within the industry.
“The challenge was that this grinding booth needed to be accessible by a bridge crane so there is no roof,” says Zadro. “So, we’re blow- ing air with the system over a part and captur- ing the dust so it doesn’t fly out the top or fill the rest of the shop.”
Automatic controls and monitoring Digital controls, such as those supplied by Frees Inc., are another avenue to minimize costs. These intelligent systems can sense that styrene producing activity is occurring and ven- tilate accordingly resulting in an estimated 30%-60% or more energy cost savings.
The system automatically cycles equipment off or reduces operation to minimum levels when styrene producing activity ceases. This can be accomplished in several ways, including motion sensors, monitoring resin flow, or other methods that fit the customer’s manufacturing process.
“The entire ventilation system is tied into our compressed air system,” says Douglas Caudle, president of Piedmont Fiberglass in North Carolina. Piedmont Fiberglass manufactures architectural fixtures for churches as well as a host of other products.
“With our previous system, the unit would run constantly. This system only operates when it is needed and that makes it much more energy efficient,” says Caudle. “We actually quadru- pled the size of our facility and our energy bill remained the same.”
Digital controls also allow fabricators to moni- tor and control the process through a web browser, to turn aspects of the system on and off, adjust temperatures, change timers, etc.
These controls helped Piedmont Fiberglass to reduce energy costs during three non-produc- tion days each week. “In the winter we let the plant cool down and then on Sunday afternoon, we turn the temperature up so when the work- ers arrive the plant is at operating temperature,” explains Caudle.
Temperature control for worker comfort One of the major benefits of a state-of-the-art ventilation system is facility cooling and heat- ing to keep the shop at the recommended 70-75 degrees for worker comfort and the process itself. Constantly warming sub-zero degree incoming air would require exorbitant energy costs, as would constant cooling on a muggy 90 degree day.
Today’s ventilation systems utilize heat recov- ery equipment to recover the bulk of the heat from discharged air to heat the incoming air. In the summer, evaporative coolers are similarly employed.
For Structural Composite Technology, Manitoba winters fall well below zero degrees. The ventilation system uses recaptured heat from the 70+ degree air as it leaves the building through heat exchangers to warm the - 20 degree outside air to approximately +40 degrees – a zero cost energy gain. The natural gas required to further heat the air to 70 degrees is a fraction of the cost, and saves the company an enormous amount of money every year.
“Our utility, Manitoba Hydro, did an energy audit on our system and with the heat exchanger and digital controls and based on incentive pro- grams the utility paid for the first year of our energy sys- tem, reducing our payback by a year,” says Zadro.
At Piedmont Fiberglass, hot muggy summers in the South required an evaporative cool- ing system. “We are in North Carolina and in the summer it
15 gets unbearable,” says Caudle. “In the shop this year, the guys were very comfortable.”
Showcase facility “Our ventilation system has allowed us to showcase our facility with pride,” says Zadro. “We constantly get calls about our system from other fabricators, because they want to know about it.”
With OSHA and EPA currently developing new, more stringent regulations, it is clear that conventional ventilation systems will not stand the test of the air quality requirements that lie ahead.
“In years to come, as regulators get their teeth and don’t allow the grandfathering in as far as other fabricators we, with pride, can say we are already there,” adds Zadro.
For more information about Frees Inc., call 1- 800-978-FREES, or visit www.freesinc.com. The company is located at 2524 Samford Ave, Shreveport, LA 71103.