Airslide vs Pressure Differential

[daniel_leavitt2000]

I know the basics of pressure differential are different from the mechanics of Airslide - the former pressures the whole car to aid in unloading where airslide uses puffs of air to move fabric bladders to unclog caked discharge openings. Do the cars share the same air inlet and discharge plumbing? Can a truck unloading from a PD hopper use the same equipment for an airslide?

[learmoia]

I know the basics of pressure differential are different from the mechanics of Airslide - the former pressures the whole car to aid in unloading where airslide uses puffs of air to move fabric bladders to unclog caked discharge openings. Do the cars share the same air inlet and discharge plumbing? Can a truck unloading from a PD hopper use the same equipment for an airslide?

I.E. could an airslide and PD be used in the same customer and same commodity?..

Good question.. although airslide were typically used for food grade products and PDs used for cements and clays correct?

-Ian

[daniel_leavitt2000]

Ian,
NACC/Thrall/Trinity PD5125 hoppers were used by ADM and Interstate/Continental Bakery/Wonder Bread. Both companies also had sizable Airslide fleets as well.

And then there is this:


This is the only photo of rail equipment at the Wonder Bread plant in Natick, MA. The foreground is obviously a PD5125. But what is the ribbed hopper in the background? I know its not a 2 bay Airslide, which was what WB owned. Its too small to tell if its a single bay Airslide. And it could be a standard grain hopper. But that would result in even more questions... Why unprocessed grains if you have processed grains available with the PD hopper? Why use multiple unloading equipment when they could standardize on a single mechanism?

[eja]

And then there is this:


 it could be a standard grain hopper. But that would result in even more questions... Why unprocessed grains if you have processed grains available with the PD hopper? Why use multiple unloading equipment when they could standardize on a single mechanism?

It makes one Wonder, doesn't it?

[learmoia]

Ian,
NACC/Thrall/Trinity PD5125 hoppers were used by ADM and Interstate/Continental Bakery/Wonder Bread. Both companies also had sizable Airslide fleets as well.

And then there is this:


This is the only photo of rail equipment at the Wonder Bread plant in Natick, MA. The foreground is obviously a PD5125. But what is the ribbed hopper in the background? I know its not a 2 bay Airslide, which was what WB owned. Its too small to tell if its a single bay Airslide. And it could be a standard grain hopper. But that would result in even more questions... Why unprocessed grains if you have processed grains available with the PD hopper? Why use multiple unloading equipment when they could standardize on a single mechanism?

It looks like a Conrail Single bay airslide or something similar to a dry-flo.  I don't think it's a grain hopper.

~Ian

[Robbman]

I know the basics of pressure differential are different from the mechanics of Airslide - the former pressures the whole car to aid in unloading where airslide uses puffs of air to move fabric bladders to unclog caked discharge openings. Do the cars share the same air inlet and discharge plumbing? Can a truck unloading from a PD hopper use the same equipment for an airslide?

Yes.

Airslides work similar to an air hockey table... it's not a bladder, but a coated fabric that has billions of tiny holes... the pressurized air fluidizes the commodity several inches above the fabric, allowing for gravity unloading.  Gravity pneumatic outlets (similar to a PD, you just didnt open a hatch on the car and watched pressure carefully) were an option on Airslides as well...