Pneumatic trailer unloading

Had an O/O with a dedicated vacuum run of lubed plastic, this stuff would flow out a railcar left open on it's own..

Stuff loaded 48K in under 30 min and unloaded E Z.

Fred would open #2 and most of the product would flow out.

Then a few minutes to clear #1 then on to #3 and #4.

Sometimes he would let it get too hot and would buy the loader lunch to get the clump out....

Short haul, he could to 4 in a ten hour day.

 

I've never hauled calcium but I tried unloading all three at once with popcorn lime. Tried it once.
Never, ever, again. We wound up bringing a new discharge hose out from the shop and finishing the unload that way. The old hose was packed solid.

 

Yea lime is one that will clog very easy even with just one pocket at a time. You've got to be careful with that.

 

Pebble lime especially - I HATE that stuff! Crushed lime is a lot more forgiving, and a lot less abrasive to your unloading hose.

 

Rock salt is another product that can be a nightmare to unload. It's supposed to have a specified moisture content when it's loaded, otherwise it will clump up in your trailer. We only hauled a couple of loads of it . It sat all weekend in the trailers. Set of Beale doubles. Good trailers for cement or lime.
Got to the unload point and nothing would blow out of the trailers. Nothing. Raised the domes and looked inside to find big clumps of salt.
We unloaded it by taking the bottom drop covers off the trailers, turning the vibrators up all the way, one guy on top with a poke rod, two guys on the ground with a rubber hammers, one guy driving slowly back and forth while we windrowed that crap.
We hauled two loads and the reason we hauled two was because we couldn't believe how bad the first one was. The second one was just as bad.

 

That's the kind of stuff that needs to be bottom-dropped into a pit.

 

I agree. The next time we hauled it it was in super-sacks.

 

Dump Truck comes to mind.
Early 80s I loaded a 48 ft rag top right out of the ponds at Morton salt at the Great Salt Lake plant.
Dumped the salt in with a frontend loader.
Never loaded another ..
Was told that they drove the trailer around the Chicago yard with a couple of dock hands shoveling salt out the back.

 

Sounds about right. We hauled quite a bit of it in super sacks but I saw a lot of those sacks, still full, out behind various highway department sheds for a long time afterward. They said the best way they'd found to unload them was to pick them up with an FEL and drop them onto a concrete pad...again and again and again. Then they'd run over them a few times with the FEL. When the clumps were small enough not to clog the spreader truck's hopper they'd load it and send it.

 

Generally it's ok, However if one of them runs out of product before the others it coulf cause you a problem. While your learning I would reccomend sticking with one pod ata a time, and when you see a pressure drop stop close that product valve and open the next. At the end you will be blowing them out completely.
How far you open the product valve depends on the product and the push. When unloading sand I would run about half, and adjust from there, vs cement I would run wide open. Ran pheumatics more than 15 years, everything from Sand, Rock, Quicklime, lime stone, cement, dirty water, to honey, molasses, salt. Every type of load can be different. Bottom line think about what you want the air pressure to do for you, adjust in small incraments.