Improve at offloading Pebble lime

Put your tank pressure up to 14 pounds.

Open rear pot. Add line air to unload.

Your discharge hose should get alive like a snake. Stand on it to make sure the product is moving within.

Keep your tank at 14 and keep a eye on the line air ready to close pot and add full air to the silo should it try to plug on you.

Hopefully you are using electric plant pump. And not your truck's exhaust turbo. The 400 horse electric pump at plant will be a much more stable source of air.

When your pot is empty close it bring tank back to 14 pounds and open middle pot.

Repeat as before.

When you get to last pot if you are truly empty your trailer will start to sing.

DO NOT keep feeding air into tanker off Plant supply if possible when empty so you do not plug up any other Bulk tankers unloading with you.

 

I've hauled a fair amount of pebble lime, but it's been a few years since I've done it last. So take this for what it's worth.

If your trailer is equipped with top air, use that instead of the aerators. Remember, it's pebble, and there's no need to fluff stones, gravity will move them.

I'd set my tank pressure at 14-15 psi to start, using top air, and then regulate the pressure as needed. Sometimes it would fall back to 10 psi and settle there, other times it would climb to 17 psi. I would let the pressure settle where it wanted.

Line air is what you want to pay attention to with pebble. Use lots of line air. Remember, gravity will naturally make pebble fall to the bottom of the pipe, so you wanna keep the stuff moving, so line air is your friend. It's more important than tank pressure with pebble. I'd regulate the tank pressure by the amount the product valve is open. So if you find the tank pressure climbing, close a product valve somewhat. If tank pressure is falling, open the product valve a bit. I never ran with more than one product valve open at a time with pebble. And I rarely had the product valve open fully.

Another thing to look at is the pipe you're unloading into. Is it a straight run up into the silo, or is the silo a hundred feet away, with horizontal and vertical pipes with lots of elbows in it? Having alot of elbows and horizontal runs turns it into a whole other challenge. And again, line air is your friend.

Had a place in Massachusetts we'd go to, brand new facility. The silo was something like 80 feet high, but it was around a corner and close to 100 feet away from where we unloaded. So we had a pipe that ran horizontal for about 40 ft, then a 90 degree elbow, then up 20 or so feet, then horizontal across a roof top to an elbow that went up into the silo. It was just about the worst place we unloaded. Everyone, myself included, would block it up on a regular basis. It just sucked. I learned to not be in a hurry with pebble after going there a few times.

That's another thing, don't try to be in a hurry unloading. It usually gets you nowhere in the long run. This has been proven to me over the years of watching my co workers. They'll hook up, pressure up, and throw all the hoppers open at the local redi mix plant, and have to babysit the trailer the entire time, with a constant hand ready to slam a valve shut at the slightest hint of a blockage. They may get done unloading faster than me on occasion, if they don't block up. But I very, very rarely block up. I let the trailer do the hard work. So at the end of the day, I'm usually done before those guys that are in a hurry all the time.

 

Blowing off pebble lime just plain sucks.
@rbrtwbstr is right, use lots of line air and don't get in a hurry.

Also, pebble lime is abrasive and will chew up your discharge hose from the inside. Watch for bubbles. Always have a spare hose, or at least a scrap piece of hose (cut lengthwise), some hose clamps, and a 5/16ths nut driver to patch it up until you finish unloading and get back to the shop.

And no matter what kind of lime you're unloading, always have a big jug of vinegar just in case.

 

Late last year and early this year I was running coarse pebble lime into ND to various water treatment plants from Manitoba (about 6 months straight). My fastest unload was somewhere in the neighbourhood of 55 minutes for 29 short ton.

It's a different load from almost everything else you can put into a pneumatic.

The key is high pressure (12-14 psi) constantly. Charge the tank up to near 15 (not aerators, but direct to tank for full top pressure), then crack the line and start adding product. You'll likely have to almost fully open the product valve to get it moving, and you'll need to watch it like a hawk the entire time.

Never let the tank pressure below 12, or you'll clog instantly, and don't add more product than it'll take (every trailer is going to be different) or you'll clog. It's a very fine balance point that'll take practice to find.

Good luck.

EDIT: Forgot to add, are you blowing it into a silo with suction? Because that'll help a LOT. The better the suction, the easier the job.