Air Cooling for Plastic Manufacturing

Welcome.

I think your idea is worth trying. It seems simple and easy to implement.

One problem may be the condensation form the AC units.

Even here in Arizona my 4 ton house AC produces 5 gallons per day of condensate, in the summer.

Try it.

Don't suppose too many places in the hotter parts of Africa would be upset by having an extra 5gal/day of relatively clean water.

Good point.

If, as you say, this is a large blower, then you would need a pretty high capacity refrigerated unit to keep up with it. May be better (and cheaper) to consider a largish evaporative cooler, either roof mounted and ducted or even free standing close to the process.

If the outside is not much humid you can use evaporative cooling process to reduce the air's DBT. This will be cheaper than the air-conditioning .( Both capital cost and running cost). But to operate evaporative cooling you need water .

I ve seen portable, free standing (floor) AC units used in converted steel container-to-offices (6m), also in Africa. Seems to work OK in that volume of void.

I have actually seen thses a few times, but did'nt take note of manfacturer details..sorry. They have a large dia discharge hose (about 8"), and I reckon you can adapt this for your ring-blower input.

Apologies for such scant detail...

http://www.airconco.com/buy/airrex_hsc_2500_portable_air_conditioner

Hope this is of use. I understand that you only need to cool the air immediately around the extruded material...in which case, this unit is a bargain today!

Thanks for the input so far everyone, amazed at the number of responses. Seems like a great community here, going to hang around here more for sure and contribute where I can.

If you are not working 24 hours per day, consider changing shift patterns. Air temperatures in Africa drop substancially over night. Two shifts, say 19:00 to 03:00 and 03:00 to 11:00 would certainly reduce the cooling load and may remove it completely for part of the production.

Not an option unfortunately we run 24 hours. Made contact with these guys and they will send me a unit tomorrow to test. http://portacool.co.za/products-2/

Maybe try out a method that does not use power, for example a long black chimney, that during the day gets the full effect of the sun, which will warm the air, causing it to rise, sucking in air at the bottom, where it is "taken" from the air around the part that needs cooling.

Once it starts and if the air inside is warmer than the outside even at night, it may continue to work at night as well.

The secret is to get the part above the roof as high as possible, which will increase the speed of the air quite dramatically. Maybe a wider tube above the roof line. Some experimenting will be needed,

If you have a hot water system with water that needs cooling, that can be used to feed heat into the chimney at night and cool the water.....and maintain the sir buoyancy.

Its called the "Chimney or Stack Effect".

Read here:-

Chimney or Stack Effect

Best wishes.

Blowing film takes a lot of air.

Take a look at the process, and you'll understand.

So we need more air cooling than the normal drop in temperature from when compressed air is released through a nozzle?

This may be a silly idea, and it may be too late to implement at this plant, but has anyone thought of building the plant underground? There may be ventilation issues to deal with, but if you put the whole building out of the sun, you might be able to run the plant in 'cool cave air' instead of 'hot savanna air.'

You might even be able to get the effect by 'burying' the building, using the thick dirt walls as a thermal barrier between the building and the blistering African sun. Keep the building access on the North side only, or better yet, an entry tunnel to get that 'cool cave air' effect, and a 'heat exhaust' vent at the top of the 'ant hill' mound, and you should get a natural convection flow to maintain cooler temperatures inside the building.

As I said, these may not be practical or properly timed for this project, but I was restricting myself to solutions that used 'passive cooling,' and did not require rare or expensive materials to complete. (I would have used the phrase 'dirt cheap materials,' but the accidental put would have been so obvious as to be offensively unfunny.)

I thought he just wanted to cool something down.....

If you have compressed air available Vortex tubes could be placed on the air ring to drop the temperature.

Have a GA point on me, you beat me to it.

Taking your idea one step further, why not introduce the cold air from the vortex tube directly into the air ring. That way the cooled air comes directly out of the air ring.

By putting them on the air ring. I meant to use them to inject the cold air in to the ring. My not have come out that way.

Not familar with the process. It could be if the blower can maintain a pressure and you can get enough air flow need that air could be used.

That's just the way my mind works. Literally.

I've never used vortex coolers so I'm no expert either.

I've used a ton of these:

Paxton 5/7.5/10HP blowers for air blow-off and drying where heat was a good thing.

Hi, I work in the evaporative cooling industry. If your interested in an evaporative cooler this may be the solution for you. The company is called Portacool, it is a division of the Walter Meyer group. Portacool distributes their products in Africa. Portacool has an extensive product line, from small spot coolers to large industrial sized coolers. Many of their coolers are mounted on wheels so you can place them where they are needed.

Contact Mike Adair at: madair@portacool.com

Mike is the Distribution manager for the western united states.

Thanks everyone for your feedback and suggestions. I managed to get hold of a portacool locally as suggested by tonyhemet. Burnt out the pump in the first week cause of manually filling the reservoir and found the pump to be a common submersible to sorted that. I first had it blowing in front of the intake of the blower but later attached the portacool to my blower so that actually sucks the air in from the portacool and I can keep the fan on the portacool off. It has dramatically cooled down my air-ring and the air that flows through is a lot cooler. Now that I know how this all fits together I might just build my own permanent coolers.