6 replies to this topic

[pghosh]

Does anyone have experience with in-line sieves when unloading granulated sugar into silos?

 

One of our sugar suppliers do not recommend this since it could lead to foreign object contamination (from the sieve), sugar crystal degradation, increasing unloading time, etc. 

 

Wanted to know what's the general practice in this area. 

 

Thanks!

 

 

Piki

[GMO]

Thinking back, no I don't think I ever have.  But that was into the beverage industry where sieving the work in process (once made into a sugar syrup) not much later was going to be far easier.  I'd agree that any hint of moisture on that sieve and it's blocked.  Not impossible I'm sure but you'd have to keep it dry.

[TimG]

Used gravity sieves in line while bagging (sugar industry). I can't say foreign object contamination (from the sieve), sugar crystal degradation, was ever an issue. The sieves were used to catch and monitor deviations in crystal size though. I had a series of shaker sieve screens (big boys, supersack size) in decreasing order and the amounts of crystal (sugar) caught on each screen recorded (quality verification step) at intervals then bagged for rework/regrading. It was NOT used as a food safety or HACCP point..

What would be your purpose or end goal with an inline sieve? 'increasing unloading time' will absolutely be a thing...

[pghosh]

Goal is to remove foreign objects (e.g. pieces of gasket) from entering our silo. 

[jfrey123]

We sieved and sifted a fair amount of sugar in my first job at a spice plant.  One we had large shaker type and it could be painfully slow depending on the mesh size needed.  It flows quickly enough with larger sizes, but you have to ask yourself what sized FM you're trying to catch.  Pieces of gaskets would range from a finger sized half of a gasket to notoriously small fragments.  Your supplier is correct that adding a sieve introduces a slight risk from other FM but I can't imagine "crystal degradation" being a thing.

 

It's weird your supplier is concerned though.  They sold you the sugar, why do they care what you do with it?  Other than that they're concerned FM found during receiving can be pinned on them and they can't argue it came from your silo/process...

[nwilson]

Never handled sugar in silos, however have with wheat flour, and we sieved the flour at the intake and at the outtake inside the building.  As others have said I would keep the sieve dry and review the screen after loading for FM.  

 

Don't see why a sieve would degrade sugar though this comment has me stumped.  

[TimG]

I know if we didn't go from large to small with our series of shaker sieves and if they weren't cleaned/checked at the right frequency it would compact on the screen and pulverize the crystal. I guess that is technically degrading the sugar and maybe what is being referred to.