Pressurized Outputs on Screw Presses

[kstitt]

I've been designing a screw press that has sealed and pressurizable outputs on both the solid and liquid outputs (the whole process will be under pressure) but I've never been able to find anything similar others have done. Has anyone heard of something like this, where the outputs aren't just to ambient air? Eventually I'll need to make the system bigger but I don't think I'll be able to do it on my own.

Thanks!

 

[ashtree]

kstitt

I have never heard or seen of such a device but that does not mean they are not out there.
Obviously you have probably thought this through already but it would seem to me that you would have to be careful with the pressures on the inlet and the two outlets to avoid leakage or slippage past the rotor either forward or between the two outlets. I would be thinking you would have to have all the ports operating at close to the same pressure.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[bimr]

Suggest you apprentice at one of the firms making these devices.

Alternatively, consider buying a unit and reverse engineering the design.

 

[MartinLe]

http://klass-filter.de/seiten/wendelfilter.html

this is a screw filter that does not discharge to ambient air: the auger transports the slurry upward, through a pipe made from fine sieve. A vaccuum pump sucks the water + solutes + fines through the sieve.

I don't know what you are filtering, and how your press will look like - I'm curious. Most screw resses I know of put some pressure on the solid phase, e.g. with spring loaded plates pushing on the solid phase like this:

https://www.youtube.com/watch?v=Z1Xcj83OIms

Probably not what you meant?

Press people tell me that the separation (at least in some media) depends on the pressure diff. across the sieve, too much and you flush more fine solids through.

 

[kstitt]

Thanks for your responses!

Martin, in answer to your question, both the solids and the liquids discharge to pipes that are still under some pressure (usually just a few psi but can be up to 50 depending on how we are running our experimental process). Basically, it means we are running the process normally otherwise with spring loaded pressure on the solid phase, just everything is shifted up 50 psi or so, both the inlets and the outlets.

The purpose for this is that we are trying to separate a slurry with the main liquid component being a fairly high vapor pressure hydrocarbon.

So if I understand you correctly you have to balance the pressure diff. such that you don't wan't to push too fine of solids through? From our experience the higher pressure differential means higher solids concentration of the back end solids output, which is preferential to us. I guess that makes sense those two things would be inversely proportional.

 

[MartinLe]

I don't kexactly now what you mean by this so i can't comment:
"From our experience the higher pressure differential means higher solids concentration of the back end solids output"
Pressure diff where and what is the back end?

As seen in the video above (should have clarified) I'm talking about a medium with lots of fibres in it. Filtering happens in the cake formed in the sieve in normal operation the remaining solids in the liquid phase are significantly smaller than the sieve pores.

I don't know your medium so I don't know at all if it will form a sort of cake and if this will help your separation.

At this point we are ruminating about presses for completely different media.