Vacuum Dryer Feeding Systems

In general terms, you may want to search for various airlock methods. What is unsatisfactory about a rotary valve or screw? If you can identify a specific problem, a solution mught be suggested.

We think that rotary valve will not held the vacuum.

We want to keep vacuum in dryer stable.

There are lots of methods to feed a vacuum dryer (screw, vibratory, belt, tray) and lots of applications issues to consider when specifying the feeder:

Material?
Does it pack, smear, break, fluidize, etc?
Feedrate?
Accuracy desired?
How will material be delivered to the feeder?

Forward me a message and I would be happy to evaluate your application and recommend a feeder type.

Thank you for the answer.

The material would be sticky powder.

Feedrate: 10 t/h;

Accuracy: 2 percent;

Will be delivered by belt.

But does your feeder could work and feed product under vacuum?

Thank you.

Considering your 10 ton/hour rate into a vacuum, unfortunately you don't have many options other than a rotary airlock. And I agree stick powders and airlocks is a headache waiting to happen.

You could look into a double-dump valve to seal the vacuum. You will still get material buildup, but maybe not as much as a rotary airlock. Link: http://www.plattco.com/

Also consider if you have the theoretical perfect no-leak valve, you are still putting in around 20 M3/hour of volume into the dryer. Valve leakage will be negligible compared to the material rate.

Since you are dealing with "sticky" paste, as mentioned in one of your responses, consider (1) batch loading, or (2) using a piston pusher, and this if properly designed will effectively seal off the dryer from the feed line, until the return stroke, when material is simply "allowed" to flow in under vacuum, then the piston pushes the material out of the way for the next shot.