conveying sugar 16' high

[randylud]

Ask and ye shall receive

Terry,
That was a most informative description of your blower system. I am with you and Eric on the vacuum problems. I used to work for a company years ago that used vacuum unloading and conveying for polypropylene pellets. I believe some of the problems we always had could have been reduced or eliminated if we had changed over to a blow system. We certainly would not have collapsing rail car situations, not that we ever did. We used vacuum breakers on all the systems and had a good pm system to keep them set and accurate. It is a very real concern though. We had bridging problems from time to time and we used bridge breakers by Thayer Scale. They were silo mounted vibratory units that would periodically shake the silo and cause the bridge to fall. Actually, since our silos were conical bottom units, we had a more severe problem of rat-holeing than bridging but the bridge breakers worked for both conditions. I am intrigued at the many ways people have solved the problems of material transport. It has always been a favorite subject of mine. Thanks for the additional info.

 

[Hootnholler]

Just to add a few more things... most everyone has hit the highlights...

I have a background in both plastics and 'dry pack' food services. A blower system seems to work the best, with sealed piping going to the machinery. Plastics is a bit easier to convey, since there is dust, but not quite the sugars and flours used in a food service.

In the food services I have worked for, they also add a 'dust collector' to the system. What it does, it sucks any fine particles to a reservoir (usually a hopper) that pulses air at certain intervals. It's not perfect, but it does cut wayyyy down on the dust floating in the air. I've also worked in a spice manufacturer, it also helps a ton when we don't have to smell the barbecue mix.

I feel for the original poster, I am in the maintenance field and have had to change a ton of components due to sugar being so destructive. The only suggestion I can make is try to keep on top of the leaks as best as possible and add a good air handling system. Everyone will be a lot happpier....

Hoot

 

[Pierre]

I've seen in an industrial show, a few years back a system which amazed me.

It was a "vibrating" conveyor. A sort of screw-shaped slide. Just like the ones we see in water parks. Only it was moving the material UP not down.

One could not see the vibration, it was very small in amplitude but when you would put your hand on the slide you would feel it.

They where conveying powder material up 4 feet with this small system and I always wondered if I would ever see one in a plant.

This could be the easy way to go.

Have any of you guys seen such thing?

 

[Terry Woods]

Sounds like a helical tube. The idea has been around for just a few years... like since about 300-BC.

Some ne'er-do-well named Archimedes, in some out of the way, backwater kinda place called Ancient Greece.

Obviously, this guy had a lot of time on his hands. Anyone ever him of him? or there?

The Helical Tube (Archimedean Tube) is based on the Archimedean Screw. The Archimedean Screw was designed to transport water. Actually, he was just dicking around and found that it could transport water.

The one you saw, Pierre, is designed to transport dry material - hence the vibrator. The vibrator keeps the material in the "valley" as it ascends the height!

Who says you can reach high places while keeping your head down?

As far as transporting sugar... it sounds PERFECT! You can carry the sugar a hell of a lot higher than 4-feet and of course you can use multiple instances!

Now... where's that damned conduit bender?

 

[jdbrandt]

transport systems

There are a number of pneumatic transport systems in use
in the food business. They generally fall into
two (or more) categories.

Dense phase: A plug of material is placed in a pipe, and air
pushes it along, usually interspersed with pockets of air.
If you remember playing with see-through straws as a kid,
sucking air, then slushie, then air, you get the idea. The
material needs to be rather 'clunk=prone', and the pipe
needs bypass air actors around the outside. This also
involves something called a pressure pot, or transporter,
which gathers an amount of material for introduction into
the transport pipe all at once. See www.dynamicair.com
Not much dust, air velocity low.

Dilute phase: Air is blown in a pipe to the final location,
and material is introduced into the airstream. More dust,
air velocity high. At the end, when the stuff comes into the
silo or bin, there is usually a dust collector for large
systems, or a bin vent for smaller systems. The idea here is
to let the air out, and keep the dust in.

Now, in areas where dust of any kind is totally not acceptable,
designers use HEPA filters before the atmosphere. They are
expensive and not cleanable, but they get down to the 1-2 micron
range (fine dust). Reverse flow or pulse jet fabric filters
(MY specialty) are good to 5 microns, depending on the air
volume, temperature, etc.

 

[TheCanadianBear]

Life Sucks

Some 15 years ago I worked for LifeSavers in Port Chester, New York. We used tons of pulverizied sugar and moved it up and around five stories of building. We blew the sugar from the pulverizers onto the tubes (2") then into various hoppers that had some vaccumm on them supplied by a dust collection system.

Where I work now we vaccumm convey resin pellets from external silos to the extrusion equipment. This does cause even with this method some dust, which is filtered out before it can clog the vaccumm pumps.

Thanks for listening