NASA outreach program reduces risk involved with
recycling propane tanks
Titusville, FL— Assistance
from the NASA-funded Space Technology Outreach Program (SATOP)
has solved a serious safety issue involving discarded propane
tanks. SATOP is operated by the Technological Research and Development
When the Environmental Protection
Agency (EPA) recently mandated new, safer valves for 50-pound
barbecue grill propane tanks, owners could no longer refill older
tanks and there was no way to legally dispose of the containers
because of the hazardous residue left inside.
So consumers have resorted to
leaving them near landfills or hiding them inside discarded refrigerators
or other large appliances, according to Sonia Gribble, president
of Tri-State Scrap Metal, Inc.
The Asheville, North Carolina
based company recycles tin, steel, aluminum, copper, brass and
other materials from throughout the Southeastern US. The outfit
handles several thousand propane tanks annually, she said, including
a recent single batch of 1,000.
“Not long ago, one of my
heavy equipment operators accidentally dug a hole about three
feet deep into the ground when he was loading other scrap metal
because a tank was hidden inside,” Gribble said. “There
was a small explosion. That’s very scary.”
And it wasn’t the first
“When we travel to county
landfills, we’re constantly encountering propane tanks,”
she noted. “It’s very dangerous because there are
still fumes inside. It’s especially hazardous if anyone’s
smoking in the scrap metal piles. The public really needs to be
educated about this environmental and safety issue.”
Ultimately, Tri-State Scrap Metal
wanted to develop a tool or methodology that would help the company
“diffuse” the dangers presented in handling the tanks.
Gribble heard about SATOP and decided to ask the program to help.
SATOP provides free engineering assistance to small businesses
with technical challenges through the expertise of the program’s
Alliance Partners, 50 aerospace companies and universities involved
in the U.S. Space Program.
Robert Gottlieb, an associate
technical fellow at The Boeing Company/Johnson Space Center, a
SATOP Alliance Partner, solved the problem in about two hours.
“I wanted to make it a
one-stroke operation; something clever but simple,” he said.
“I wondered what everyday tool would be lying around a machine
shop operation. I figured they’d have to have an air compressor.
I gave them a sketch of the idea and they took it from there.”
His design incorporates a brass
(which doesn’t create a spark) elbow that’s welded
over the top tank opening. A hole is then drilled dead-center
through the top and a tube is inserted through the hole toward
the tank bottom. An air gun propelling 80-100 psi is then attached
to the piping.
“With the push of a button,
poof, it blows a blast of air to the bottom of the tank and the
propane squirts back through the elbow,” he said. “Since
the tubing is centered at the bottom and not along the sides,
the air pushes all of the propane above it up and out the hole.
And there’s no spark. One second and it’s done.”
Gribble is delighted with the
win/win solution. “There are no fumes left and it’s
safe to do,” she said. “Now, thanks to SATOP, I have
good, clean, recyclable steel and there’s no safety hazard
to our workers or the public.”