Companies that use aggressive chemicals often purchase those chemicals in 55-gallon drums, and the majority of spills happen when getting the chemicals out of the drums. Workers often manually lift and tip the drum or use a fork truck to pour the contents into another container, a cleaning tank or a process vessel. If the drum has a faucet, it must be manually lifted to ensure it’s completely drained. If the faucet has clogged, it must be removed and the remainder emptied. Spills are inevitable, and spill kits with related mats, pigs, dams and related equipment are necessary. Incomplete drainage can result in throwing away costly chemicals.
At Carolina Casting Inc., High Point, N.C., faucet-equipped drums of acetone were stored upright to avoid leakage, but to dispense the solvent, the 350-lb. drums were moved to another location, placed on a cradle in a prone position, attached to bonding and grounding wires, and tilted to permit dispensing through hand control of the faucet. After dispensing, they were returned to the storage area and again placed upright. The process was slow, labor-intensive and subject to spills when transferring the flammable solvent, according to Dan Stiles, plant engineer.
The company tried using rotary hand-crank pumps with the drums in a vertical position, but pump pulsing led to splashing and the pumps were unreliable and costly to repair. Air driven pumps were investigated but turned down because of high initial costs, expensive replacement parts and high maintenance costs.
“We decided to try pressure-action pumps,” says Stiles. Sourced from GoatThroat (www.goatthroat.com), “The low-cost polypropylene pumps proved reliable and permit us to keep our drums in an upright position.” The pumps are mounted on top of the drum and held in place with an airtight rubber compression fitting. Pressure is added by pumping a piston several times, which prepares the fluid to flow. Opening a spring-loaded tap starts the flow and closing the tap stops it. An internal safety design relieves pressure if the vessel reaches 7 psi, which meets UN safety standards.
At Carolina Casting, fixed grounding and bonding wires are hooked directly to an adapter that delivers compressed air at 2 psi. “This has proved ideal for dispensing into small containers,” says Stiles, and also is available in larger, mobile units for filling 20-gal. to 40-gal. containers at 3.3 gpm. “No more bucket-carrying of acetone,” he says. “The new procedure is faster and safer, and has helped us exceed our environmental compliance requirements.”