Decreasing Unload times for Pneumatics

Are all this answers the same with sand product? If so does it apply by unloading it faster?

 

Do this answers include with sand product? If so does it apply by unloading it faster?

 

I've never unloaded sand. My experience is with fly ash and cement. Fly ash takes longer to unload than cement all else being equal. I can *usually* unload cement in around 40-45 minutes if going into a silo. If going into pig, I can unload in as little as 20 minutes. You can add 10 minutes or so for fly ash. Why? I really don't know.

What I do know is different products take different times to unload. Lime, for example, is pretty slow at unloading.

 

With frac sand, I used aerators to build tank pressure to 12-14 psi, and then ran with one hopper fully open, line valve fully open. Top air never did much with sand. It just seemed to not flow as nice with top air.

Sand is obviously heavy, so my thought always was more air in the line to push it. With a short 8' hose going into a pig, I could unload it in under half an hour. The longer the hose, the longer it's going to take. For some reason the length of the hose makes a huge difference with sand. With cement, not so much.

 

Hmm i see... well i tried this one video on YT from “chase butler” on how to unload and did the exact same thing that this person did but right after i started opening the product valve all the way my line Pressure just went up from 0 to 16psi and tank was at 12psi and in 2 seconds tank was following tge line pressure i couldn't understand why but at the end i stabilized it with line at 100% open, the aerators at 20% open and with top air and blowdown closed. Im not sure what went wrong

 

I'm fairly new at bulk myself and have tried many different ways and have always ended up screwing something up. Haven't hauled food grade yet but I have hauled soda ash. I usually get a 4 hopper with no aerators unloaded in about an hour & 15 minutes. I leave the tank and line valves wide open and control the PSI with the product. If it gets too high, I back off the product. Too low I increase the product. It works for me

 

Can someone on here explain unloading cement into a spreader truck with bags on top? Specifically how to do it quickly without blowing the bags?

 

When I do it, I run the blower at idle or just above idle. I keep the tank pressure at around 12 psi, and the line valve open about 1/4 of the way. I open 2 hoppers at a time, if I try all three it just plugs it up. The idea is to move as much product with as little air as possible.

When your hoppers are near empty, close them. Don't let them go completely empty. Keep just a little in each cone. This avoids the bust of air that you get when you go empty, which is a major cause of blowing bags off. Once the trailer is almost totally empty, I'll bring the tank pressure down to around 5-8 psi. I do this by either opening the line valve some or crack your blow down valve to release the pressure. And I'm doing all this while unloading the last hopper. Then do your clean out on all three hoppers.

That's how I've been doing it, usually takes 20-30 minutes to unload 26 ton. Your results may vary

 

I recommend this, as that's how I mostly it as well, only a couple things I do a little different, I run my rpms up to get trailer to build pressure (mine has always taken a little bit to build pressure at first, but once initial pressure is built it'll maintain it where I want it and would drop it back to just above idle) and when I unload I have always went middle, back, then front pocket bc mine will plug up if I open one and a second more than halfway, just depends on trailer as to how many you can open at once (Mine unloads faster with just one open than trying to force it by more than one at a time). When unloading I let the pressure just start to drop, just a pound or 2, as you could always tell the difference in the vibrators when the pocket was just about empty, then shut it off and switch pockets. Once I am on the front one, and it's a little over half empty, i start with the back pocket and open it about a 1/4 of the way, and let it vibrate out and watch the pressure and let it drop a few pounds, then do the same for middle one, and by that time front one is almost empty and have slowly released some of the trailer pressure. Once the front pocket starts dropping, I close it and start at back pocket and open it about halfway and once pressure started to drop I would shut it and go to middle, and do the same and then same with front, and by time I got to front one I was down to a couple psi. and could let that one finish cleaning out and didn't have to worry about a huge surge of air going to spreader truck.

Sometimes blowing a bag might be unavoidable though, I have blown a couple off in my days, one was one they just changed and didn't tighten the clamp enough, and another that they knew they needed to change them but kept trying to get more out of them as they was pretty well plugged up from rain the prior few days.