The rear chute wall in this image is bolted onto side fl anges, allowing safer access
MATERIALS HANDLING
What steps can conveyor operators take to make chutes, silos and hoppers safer? SPACE ENTRY SAFE CONFINED A
n estimated 7% of the USA’s fatalities recorded by MSHA between 1995 and 2011 occurred in a confi ned space. To reduce that
number, conveyor operators are wise to understand exactly how a confi ned space is defi ned, and to consider what they can do to prevent serious injuries. Many factors can cause bulk materials to adhere to the sides of chutes, silos and hoppers – including humidity, moisture content, size/ texture of the raw material or increased production volume – resulting in lost capacity or clogging. Ongoing accumulation reduces fl ow and eventually stops production in order to address the issue, causing expensive downtime and requiring extra labour to clear the obstruction.
“Clearing extensive build-up often
involves confi ned space entry, but the consequences of untrained staff entering a chute, silo or hopper can be disastrous, including physical injury, burial and asphyxiation,” says product engineer at
Martin Engineering, Daniel Marshall. “Without proper testing, ventilation and safety measures, entering vessels containing combustible dust could even result in a deadly explosion.”
Proper air cannon placement in chutes and silos can reduce ongoing build-up
WHAT IS CONFINED SPACE ENTRY? T e Occupational Safety and Health Administration (OSHA) defi nes “confi ned space” as an area not designed for continuous employee occupancy and large enough for an employee to enter and perform assigned work, but with limited or restricted means for entry or exit. “Permit-required confi ned space” means a confi ned space that has one or more of the following characteristics: the vessel contains or has the potential of containing a hazardous atmosphere such as exposure
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