Pellet Boiler Maintenance Tip #3: Why do pellet fines concentrate?

Fines Concentration mainly occurs in silos with 45 degree or lower slopes due to funnel flow.  Silos with bottom slopes of 60 degrees degrees tend to accumulate far fewer fines because pellets go down in a Mass Flow.  See the graphic. 

The MESys FleXILO interior pellet silo is an excellent choice.

The MESys FleXILO interior pellet silo is an excellent choice. This picture shows the silo in near-empty condition where the side springs have lifted the outer edges of the floor into a V shape, dumping all pellets and fines into the central auger.

The MESys FleXILO interior pellet silo shown full of pellets.

The MESys FleXILO interior silo when filled with pellets stretches the side springs to flatten the floor which makes the bag into a cube–taking full advantage of the footprint area.

The Froling interior pellet silo has 45 degree sloping floors that don't have fines build-up if their vibrator is installed with it.

The Froling interior pellet silo has 45 degree sloping floors that don’t have fines build-up if their vibrator is installed with it.

The cures for fines build-up? One is to Vacuum fines out of your low slope silo when it becomes “empty”.  Do this once a year or so which will prevent heavier concentrations that occur after years of fillings.  Vacuuming out a bag silo every year or two is also a good practice, even with a MESys type “Spring-Bag” (see photo).  If you have a Froling funnel bag, a vibrator can be added to these that runs when the feed blower turns on, getting fines to exit with the pellets before they become concentrated.

A 28 ton silo with a 60 degree bottom cone.

This 28 ton pellet silo has a 60 degree bottom cone which is highly advised to control pellet fines concentration

Planning a pellet boiler installation for your home or building?  Choose an interior silo like the MESys FleXILO “spring-bag” that looks like a cube when full but the springs pull up the floor into a steep V when it nears empty.  Or get a Froling silo with a vibrator.  If you are planning on an exterior silo, the 60 degree bottom cone is recommended with pneumatically filled boilers.

Next week we will continue this topic.  If you have experience with fines build-up, please comment and send photos if you have them.

Pellet Boiler Maintenance Tip #4: A Solution to Fines Build-up
Pellet Boiler Maintenance Tip #2: Fines Management
Share this