Drying a powder

This sounds like homework, again.

Me, I'd just run a couple batches through and do some before and after weighing.

You might ask this guy, he may know, Water out of tube? He's trying to dry a tube. You guys in the same class?

That's easy. Just time it till it's half way dried, then double the time.

Hi TVP45,

That's easy. Just time it till it's half way dried, then double the time

Now why didn't I think of that? So obvious really? LOL!

Take care.

Hi JaE,

Seems to be a pretty good answer. At least as much as this question 'can' be answered?

You could also bring in the grain 'shape'. Is it mixed or all more or less square, round??? What is the spacing and thickness of the trays?

Would not there have to be some kind of recirculation to dry the top shelves as well and at the same rate as the lower ones?

I am pretty sure this is homework. In which case any mention of the methods described will have already been discussed and the answer already found; just a case of perhaps 'listening more carefully' on a Tutorial next time?

Can someone tell me, if this is to be dried, why leave the drying process at .5%? If it is a powder would it not benefit from total drying? Perhaps to an even 'cake' then be ground again if necessary? The method proposed seems very 'hit and miss'.

I love your answer

Define: Drying

Make it a closed batch process, and optimize your circulation and exhaust suction level bare minimum to avoid particulate carry over with dry air.

The other best options could be the use of radio frequency or microwaves, where drying rates can be faster and control can be better.

IR heatingcan also be tried.

Hey Guest,

Don't know if this would help, but a recent Dept. of Energy newsletter gave a brief description of experimental process to dry coal particles (fines) so as to be able to recover them from processing waste and burn them as fuel. If I remember correctly it involved subjecting the wet slurry to heat and pressure. I thought it was interesting because the use of pressure was , to me, counter-intuitive, ( you know, vacuum freezing , the process that renders mine waste , into Taster's Choice instant coffee). The newsletter can be accessed on the Dept. of Energy website.

p-rat

It depends upon the dryness of the air coming in, and the ability of the air to pass through the powder instead of going round the aluminium trays instead.

Field trials will determine the best way of doing the drying, rather than equations.

Heat the tray from the top with infra red light radiation.

This can be obtained with electrical tubes or gas radiators.

The temperature can be controlled changing the height and capacity of the radiation panels.

You will need an exhaust port on top of the radiating panels for as natural outlet of vapour and an inlet port for replacement air.

No need of forced air circulation or blowing.

You will have to do some field testing for the amount of residue humidity. More time less humidity.

We dry sludge this way from 15% to 1% humidity.

cheers

I got it why not just suck up the top dry particles

and leave the wet ones

to go around again until they dry

I love my vacum pump and hair blower

and just slaming the dust particles around with 200 psi

just makes the dance so much more attractive

and if you can get them to spin

hey suck them up

in a swirl

and let them dump free falling into a container

by spin and suck you get to all the granuls

for get the pizza trays

if this is not home work

all rules barred with the exception of .5%

whats with that

why do you need .5%

what is the process that requires .5%

are you mixing it with what

is this powder for your face

and you want to keep .5% moisture on your skin

explain a little more

need more input johnny 5

Wow, are you Tom Waites? Awesome answer, needs piano accompaniment though.

p-rat