Pneumatic trailer unloading

So quick question. I'm new to these trailers as well. I just ran my 2nd day solo. I've had my cdl for 12 years just never these trailers. I'm currently unloading at 13.5 psi. But I'm unloading all 3 pockets at once. They're all opened slightly less then half way. Pressure is staying put. But my question is about the pockets. I've heard people saying it is ok to do and others say it isn't. I was just curious if I could get some clarification from someone with more experience then me. Thank you guys.

 

As long as you’re keeping pressure and product is moving there’s nothing wrong doing it that way.

 

I'd rather do one pocket at a time but that's just me and the way I'm used to doing it. With all three product valves open you might be a little slower responding to a plug than you should be. A small plug can usually be handled quick and easy. A large plug...especially one that's impacted on itself because the product wasn't shut off...will have you hating life.

 

It depends on what product you’re offloading.
I’ve tried the multiple drops open and found that a single drop was faster for the plastic pellets i pull.
It maintained line pressure within spec only with constant monitoring, but single drop set it and forget it, kinda.
I run my tank pressure to 10, open the bottom and reduce top air to about 10%.
That gives me maximum airflow through the bottom pipe to move the most volume of product in my application.
I’m required to maintain between 7.25 and 7.75 psi line pressure to prevent problems with the material getting too hot and Angel hair deforming.

 

I appreciate it guys. And the product I'm moving is type 1 for cement and slag. But I did notice it took alot longer with all 3 open so I went back to one at a time.

 

If you ever get a load of rock salt be sure to unload one pod at a time.

 

Here is the best way to unload cement, fly ash, crushed quicklime, and frac sand. The theory is to put as much product through the discharge line as possible without plugging up, while maintaining tank pressure. The shorter the push, the more aggressive you can be.

1. Before you connect your discharge hose to the facility's fill pipe, take a mini-sledge and give the fill pipe several good raps above the fitting, to knock loose any crap that may be built up inside. Then connect your hoses and start the blower with the discharge valve closed and the aerator and blowdown valves open.

2. Close the blowdown valve ans pressure up the tank using the aerators only (no top air), then open the discharge valve all the way to blow any settled product out of the discharge line. Once the line is clear, adjust the discharge valve to halfway open.

2. Open the rear pod all the way, then open the center pod halfway. Adjust your discharge valve as necessary to keep from plugging up. If your discharge valve is still halfway open or more, open the center pod the rest of the way and then adjust the discharge valve as needed to keep from plugging up.

3. When you hear the aerators on the rear pod start rattling, open the front pod all the way, then close the rear.

4. If the center pod empties before the front pod, close it and adjust the discharge valve to maintain tank pressure.

5. Once they're all empty, pressure the tank back up and clean out one pod at a time, starting at the rear and working your way forward.

6. If you plug up, clear the plug by following these instructions:
Clearing a clogged discharge hose on a pneumatic?

This method also works for unloading hydrated quicklime, but instead of using the aerators you will use top air to push the product into the discharge line, and you will have to use your rubber mallet to know when each pod is about to go empty.

 

Same with me. Even though it can be done, I really don’t find it to be beneficial or faster.

 

The only time I would crack all of them open was when I’d be unloading calcium in the middle of the night when we were running hard. Calcium ran like water and opening them all meant you could look at the back of your eyelids for 45 minutes or so. Yes it was stupid to do, but a nap was a nap.