01/09/2016: “Dust explosion protection” dos and don’ts in grain and milling industries

Mark Shannon from BS&B Safety Systems shares key tips on ensuring adequate protection from dust explosions and what mistakes to avoid.

Devastating grain dust explosions have been recorded for decades as the risk of flour dust ignition is so high. Without adequate controls and safety measures, grain flour explosions have been known to level entire milling facilities and take lives.

While mill owners are making the effort to comply with DSEAR and ATEX regulations to ensure their staffs’ safety, the execution of preventive measures has not always been correct.  Many milling facilities share common problems when it comes to the installation of protective equipment. In some cases, they inadvertently exclude “fail-safes” where necessary.
  

Here are some examples of the most regularly encountered issues when it comes to protecting against dust explosion risk in grain processing and milling. These observations come from years of experience.

Always seek the help of a professional to visit your site and make the recommendations bespoke to your facilitys’ needs.

1. The management of hot particles 
By detecting and preventing sparks, embers and hot particles from reaching dust rich downstream process equipment, such as dust collectors; bins and silos, both fire and explosion risks can be managed.

Dust explosion severity classifications are measured from St1 to St3. Grain dust has an St1 rating – not the highest explosion severity, yet grain dust can ignite at a fairly low temperature and that makes it a dangerous combustion risk. If a known risk may exist then a spark detection system should be installed to counteract the risk of severe damage and harm to personnel.

2. Don’t forget to protect Bucket elevators

Bucket elevators are high risk equipment because they have many possible ignition sources. What’s more, they are usually connected to the rest of the plant, so if there are sources of ignition, a primary explosion could easily spread to the other processes and a secondary explosion occur.

3. Overlooking isolation of connected equipment

If you fit an explosion vent to a dust collector, then there must be isolation of the dirty inlet duct and isolation of the clean air outlet duct if it returns to the process area. 

This is vital because the explosion could propagate along these ducts causing other safety risks to people and equipment. Non-isolated equipment could cause a chain reaction of explosions. 

Read the full article HERE.

 

The Global Miller
This blog is maintained by The Global Miller staff and is supported by the magazine GFMT
which is published by Perendale Publishers Limited.

For additional daily news from milling around the world: global-milling.com