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jenboi
17-08-2012, 12:30 PM
Hello
Normally my partner and I make Robotic automation cells and mechanics, but we got this additional inquiry of making an air blower cooling tunnel.
So, due to no floor space, I´m investigating the possibilities of making a vertical air-cooling tunnel, floor space approx 1x1m. The tunnel shall cool down zinc die casted items of various sizes and shapes. The items are conveyed through the tunnel in a vertical oriented oval-shaped track. The robot picks and places the items at the same entry hole.
Known input: Cool down time 6 minutes, Capacity 27 kg zinc/6 minutes, weight per item varies up to 1.5 kg, T1=approx 300 C, T2= approx 30 C, ambient temp approx 21 C
I calculated the amount of energy to be removed according to: Q=Cp X (T1-T2) X m
This makes: Q=0,38X27X270=2872,8 KJ to be removed in 6 minutes gives 2872,8KJ/360sek=7980Watt
Is this way out?
Questions:
1) How do I calculate/estimate the air blower capacity?
2) Guidelines for placing the blower unit(s)
3) Anyone who happens to know if it´s possible to buy such a “standard” solution, I haven’t been able to find one myself :confused:

chemi-cool
17-08-2012, 01:32 PM
You have to take into consideration that part of the air will just pass in the tunnel without cooling the Zinc.
Another thing is, where do you take the air to be cooled from and where is going to afterwards.
If the work is constant, the room will get much hotter.
Is there a possibility to prepare the daily amount in advance? This way you can simply cool it using ambient air and you can use it at 21C. Just a thought.

jenboi
17-08-2012, 02:06 PM
The air from inside the productionfacility (21 C) is to be blown into the tunnel, the outlet is not yet considered, maybe connected to the existing ventilationsystem at the die casting machine.
It is mostly 24/7 production, only paused by die tool change or service.

r.bartlett
17-08-2012, 02:06 PM
a cooling bath may work better with a dry cooler to reject the heat outside. Problem with air is the rate of heat transfer may not be sufficient... I had a similar problem in a bakery where air would cool the outside of the bread very quickly but the core temperature hardly changed. metal has different heat characteristics to bread but the effect may be the same..

jenboi
17-08-2012, 02:19 PM
We have been around cooling bath and that is a no-go due to additives etc.