Large custom baghouse designed for small space
One of Griffin's satisfied customers, Carpenter Technology Corp. of Pennsylvania, is a well-known producer of specialty steel bar, wire and strip. At one part of their process, steel dust is generated by cutting saws and grinders within a lab area where pieces of product are cut, ground, then inspected for defects. The machines operate 24 hours a day, 7 days a week, 50 weeks each year. The steel dust is a dry particulate that ranges in size from 3 to 50 microns. These particles are difficult to handle because they have a tendency to adhere to each other and form a material similar to steel wool.
The existing baghouse, not manufactured by Griffin, was plagued by problems. The combination of a high air-to-cloth ratio (8:1) and a high interstitial velocity within the bag plenum was causing reintrainment of the material. Consequently, the dust was not being pulsed off the bags adequately during the cleaning cycle, which lead to an increased pressure drop in the baghouse and ultimately reduced the volume of intake air. This reduced volume caused poor evacuation of dust from the work stations. In an attempt to control the high pressure drop of the unit, the customer increased the frequency of bag replacements. Maintenance costs were averaging $25,000 a year and causing considerable production downtime.
Carpenter had several Griffin baghouses in other parts of the plant and was already familiar with their superior quality and reliability. Sales representative Ed Zondag of E-V Systems (PA) was contacted by Carpenter and, with input from Griffin engineers, recommended a properly engineered collector. In addition to excellent quality and reliability, there were several other factors that led them to choose Griffin again:
- The ability to meet an exact delivery schedule-the unit had to be installed during a plant shutdown.
- The experience to design the right hopper inlet/baffle for the application.
- Custom engineering capability to accommodate the required cloth area within a very limited space.
A continuous duty Jet-Aire, model JA-270-HE, was chosen as the best option for the application. It was designed with a lower air-to-cloth ratio of 3:1 and a larger plenum that lowered the interstitial velocity. This improved the inlet flow conditions and ensured that the dust could be easily pulsed off the bags. With a properly sized collector, the exhaust volume at the dust pick-up points now remains at design level.
Carpenter representatives report that they are very satisfied. Their lab space is cleaner and the air quality is better. Their maintenance costs have been reduced dramatically, production downtime has decreased, and their operators are pleased. With Griffin's help, all of this was accomplished on time and within budget.