Conveying - Augers vs. vacuum

[Metalworker.Mike]

I've only worked with vacuum conveying, but my company recently bought a smaller competitor that uses flexible augers for conveying. No vacuum. I'm trying to figure out the pro's and con's of this. I figure that the augers are quieter by a long shot, but would be a much heavier load on the roof system (assuming they're hung from the rafters) since they stay full. I find vacuum conveying to be a bit finicky for maintenance, but I'm not sure about augers. In vacuum conveying one motor can service umpteen different loaders, but I would imagine that the augers each need their own motors. Mind you, the augers might have pneumatic motors... not sure about that. Still, it's a different motor for each auger. Has anyone here used both systems? Any first-hand info?

[Len]

Metal,

I've used both. The augers are better suited for the delivery of mixtures that are prone to separation during transport. They are limited in they're conveying distance compared to vacuum. For example, I used mine to convey a powdered M/B (2 colors and 6 minor components) to a weighing hopper on my HI PVC Mixer. I did not want these components to separate or stratify during transport up from floor level to the mixer mezzanine, a distance or lift height of about 1.5 stories. This would have caused color shifts w/in the 60,000 lb. resin lot being converted into compound. The auger will need to be dissembled on a regular basis to clean and remove build-up and also between color changes.

The vacuum system is best used for longer haul conveying and for non-colored materials. Color or grade/product changes in vacuum system can be problematic. Also some blends will stratify and segregate over long runs, changing their composition at the destination.
I hope this is helpful,

Len

[Louis]

I agree with Len, any mixture might better be conveyed with an auger, providng the distance is not that great.

My personal preference for neat resin (pellets), even for shorter distances is vacuum as there are far less moving parts in contact with the pellets.

Still, I'd like to hear what others have to say on the topic.

[Metalworker.Mike]

I agree with Len, any mixture might better be conveyed with an auger, providng the distance is not that great.

My personal preference for neat resin (pellets), even for shorter distances is vacuum as there are far less moving parts in contact with the pellets.

Still, I'd like to hear what others have to say on the topic.

I should have mentioned that we only convey pellets and regrind, and the material is HDPE. The same is true for the company that uses the augers.

[Indy]

An auger is a screw with enlarged flights to push/measure the material into the barrel and basically ancient in use mainly found on the blenders them selves and my personal opinion of em was/still is, that you got a good, clean and consistent feed after you dialled in the speed. And all though most of the blenders that I worked with were already being fed though a vacuuming system, in time it also kinda help eliminated the need for the auger as the demands for more and faster feeds became evident.

Best Indy

[Metalworker.Mike]

An auger is a screw with enlarged flights to push/measure the material into the barrel and basically ancient in use mainly found on the blenders them selves

The company in question uses them everywhere. Right from the silo to the blenders, then from the blenders to the extrusion lines. I'd honestly never heard of doing it this way before. I've lived a sheltered life.

[Indy]

Well jut like anything one might expect a reasonable amount of trouble from somethin’/anything so after rereading the post/ reply I remembered that the auger/screw didn’t stop at times during certain jams and that the material got bound around the winding screw got hot and melted onto the screw then eventually locking up and then sometimes blowing the motor. Well hopefully you can picture it when a torch had to come out to clean up the melt which in turn took a lot of time and the blame, well it usually went to machine operator who really ought to have been watching it, butt, butt, butt and accidents do happen at times. So in my humble opinion, close loop just don’t seem to ring true here but found that turn key to be the safest bet for me. So I tried to find a layout of the auger system in question on the web and only found a few links for the plastics industry and found that it is more popular with the grain industry and probably because grain can be granulated, no trouble with the blades or flights, while resigns tend to come in a shot or pellet form I’d imagine that the regrind would be a bit more troublesome. In the meantime I really couldn’t recommend the system or not, by not being able to see the set-up. Only give you a down-side and sorry bout that.

And then I’d like to mention that good investments tend to pay for themselves, good buyers too. And oh boy if the parts/equipment buyers only knew of the loss of income and why? that is created during a down time, I'd bet there’d be a change in buying habits too “cost verses quality”.

And as I drift off the beaten path I’ll have to mention the popular tax losses write offs too that tends to keep faulty equipment alive just for that purpose. And no offence to anyone but sometimes one might think that they’d be saving money by not spending it, unfortunately it doesn’t work that way. The more that you think you are saving by not spending you’ll end up giving it to the big guy anyways “uncle” oops no Uncle Sam well that is for us Americans anyways, so I figure the best way is to spend the money the best way that money will work for you, you can write it off that way to. Better to make the money than to lose it and I think that would be the best bet for the over all economy in a big way too. Loss is always past down someway, one way or another, to eliminate the loss/losses that would eventually cut the over all costs. But mindset is a hard thing to change?

Hope you have a great day!!!

Best Indy

[Metalworker.Mike]

Indy:
I was just forcefully reminded last night that we do actually have a couple of augers in our plant - one on each granulator. If the operators don't sweep out under the granulator properly then the exposed end of the auger shaft picks up plastic dust, melts it, and the plastic goes all through the bearing, and it's a bugger to deal with. I haven't yet had to take a torch to them because the problem is external to the auger flights, but I can certainly see how the auger could bind up and 'commit suicide' in the way you describe.
The thought of potentially dozens of individual motors, some located up in the rafters, driving different augers.... it doesn't appeal. Maybe the reality isn't like that... I haven't seen it for myself.