Plastic pellet heating methods

[dextermech]

I need to think of some "outside the box" heating methods for a column of plastic pellets. Currently hot air is blown through the pellets to heat them. Another way is to run them under an IR heater. Can anybdy think of some alternate ways? Some sort of radiaion, like microwave? Help! Thanks a lot in advance.

 

[unclesyd]

We use to heat pellets by letting them fall through the cylindrical block with heated grids. Most of the heat was transfer by conduction from the grid plates to the pellets.

We heat tons of pellets by by tumbling in twin cone dryers. The dryers have 6" tubes that are heated by oil. After the pellets are heated for a period of time they a cooled as the hot oil changed to cold oil.

We tried several microwave heaters, but for our purpose they were not successful.

 

[MikeHalloran]

Put a couple of sample pellets on an old plate in a microwave even and blast them on high for a minute. If they don't melt or ignite, microwaves probably won't help dry them.

;---

Could you give us a clue why the hot air flow is not satisfactory?



Mike Halloran
Pembroke Pines, FL, USA

 

[dextermech]

How long does it take to heat them with the grids?

Airflow is not ideal because if the pellets are dusty as they usually are, the dust separates out and clogs screens, air filters...it fouls everything. Also, the largest ring compressor blower that is "affordable" is about 800 CFM, not enough to do much more than 750 lbs/.hour of material, and we need to go as high as 2500 lbs./hour.

 

[unclesyd]

What are you trying to do?

The grid system that we used wouldn't get your desired capacity.

Here is another system that we used for drying plastic pellets on your scale and larger.

http://www.witte.com/plastics.shtml

There is another system with a smaller footprint we did use for large volumes of pellets which I'm trying to get a name for. All I can remember was it was made in Edmonton Alberta. This system was used for SSP of Nylon.