Prior to using pneumatic roller railcar vibrators, railcars shipping prilled ammonium nitrate across the country faced poor material flow during the unloading process.
High Heat, Humidity, and Freezing Temperatures Pose an Extreme Challenge
Ammonium nitrate is a salt with strong affinity for water and is very soluble. In high humidity it will absorb moisture, and the small spherical prill will break down to a powder that packs the spaces between the other prill and re-solidify. Swings in temperature can also cycle the prill through its various crystalline structures and break it down, most notably around 90° F. The prill right against the sides of the railcar can bake all day in the desert sun, then cool off by more than 30° overnight on occasion.
For railcar unloaders receiving prilled ammonium nitrate, it is common to deal with a thick crust against the walls of the hopper, large chunks, bridging, and general flow problems. In addition, small chunks diminish their ability to screen the material for debris that could damage the equipment later.
The more heat and humidity, particularly throughout July and August, the worse the material flows. Operators encounter similar issues during the winter months when faced with freezing temperatures.
“In the worst times of heat, humidity, and poor prill quality, we open the door of the hopper and absolutely nothing comes out. When you look under the car you see a solid wall that hardened against the door.” – Key Customer Manager
Incorporating High-Quality Vibration Solutions to Improve Material Flow
To get railcars unloaded in this tough condition, these operators were using outdated pneumatic vibrators, air lances to poke the prill from above and below, and manually hammering the sides of the car. After hiring a contractor who specialized in unloading sticky cars using a CR 6500 and CR 7800, the team ordered the same equipment and have since handled the material themselves.
“The first time we ran the original 6500/7800 combo, we called one of our buddies who had been in the trenches with us quite a bit unloading cars to tell him in disbelief that we never hit a car with a hammer a single time and unloaded 3 of the worst cars in a single day. There had been one day previously where we unloaded half a car in about 10 hours with 3 guys, cutting all of it out with air lances and hammering.” – Key Customer Manager
At Arnold Company, our line of pneumatic roller railcar vibrators offers a full range of frequency and force, helping improve material flow. With only three internal moving parts, these hopper railcar vibrators have an extended life and require minimal maintenance.