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screen printing => Equipment => Topic started by: Gilligan on October 18, 2011, 10:35:26 PM

Title: Conveyor cool down?
Post by: Gilligan on October 18, 2011, 10:35:26 PM
Do any of you guys let your dryers "cool down" and just turn off the panels while the belt keeps rotating and fan keeps running?

I guess I just worry about the belt just cooking under those panels while still 800+ degrees.
Title: Re: Conveyor cool down?
Post by: Nation03 on October 18, 2011, 10:37:00 PM
Absolutely. All dryers should have a venting or cooling mode standard. I usually let the belt run for a good 10-20 minutes without the head on before I shut the belt off.
Title: Re: Conveyor cool down?
Post by: Prosperi-Tees on October 18, 2011, 10:39:02 PM
Your dryer at minimum should have seperate on/offs for the belt and the elements and you should let the dryer cool down for 10-20 minutes so the belt doesn't melt.
Title: Re: Conveyor cool down?
Post by: Gilligan on October 18, 2011, 10:45:46 PM
I have been doing that... tonight I shut it all off when panels dropped to 600... oops... hope that was long enough.  From now on I'll keep it rolling longer.

My control panel controls all heat, the recirculate fan and belt.  Main vent fan is always on when the main breaker is on.
Title: Re: Conveyor cool down?
Post by: Donnie on October 18, 2011, 10:52:50 PM
I usually turn my dryer off when the panels get below 300 or if I'm in a hurry to leave, I put a fan in one end after I turn off the heat.
Title: Re: Conveyor cool down?
Post by: stitches4815 on October 18, 2011, 10:58:27 PM
I shut my panels off, leave the belt running while I am folding.  When I have the shirts boxed up the panels are usually cool enough to shut the belt off.  If it is a short run I will tear the press down after the shirt folding is completed.  By then the panels should be cool enough.
Title: Re: Conveyor cool down?
Post by: Denis Kolar on October 18, 2011, 11:06:34 PM
Fan is a nice thing to have around :)
Title: Re: Conveyor cool down?
Post by: asdprints on October 18, 2011, 11:15:09 PM
I have an Economax II. When I hit the stop button it turns off the panels while the belt continues to run. When it cools to 300, it shuts down completely. I have never had to replace a belt, but I imagine they are expensive. It takes about 12 minutes from the time I hit stop till it turns off. Yep, fans help.
Title: Re: Conveyor cool down?
Post by: Gilligan on October 18, 2011, 11:35:22 PM
Bah!!  And I had a fan right next to the dryer... why didn't I think of that!
Title: Re: Conveyor cool down?
Post by: bimmridder on October 19, 2011, 07:53:39 AM
Nice thing about my M&R dryers. You shut them off. They cut the burner, and then blower runs until the temp is 150. Never a worry.
Title: Re: Conveyor cool down?
Post by: inkman996 on October 19, 2011, 08:15:05 AM
I have been told 200 or less is ideal, I do not remember why but it also had something to do with the metal workings not just the belt. Either way if your dryer has blowers and you need it to cool faster throw them on as well it will help a ton evacuating the heat.
Title: Re: Conveyor cool down?
Post by: GraphicDisorder on October 19, 2011, 08:22:01 AM
Nice thing about my M&R dryers. You shut them off. They cut the burner, and then blower runs until the temp is 150. Never a worry.

Same here, love that about our dryer, hit a button, cut the gas and walk away.  We often walk out of the shop and lock doors 30 seconds after turning ours off.  Never a worry!
Title: Re: Conveyor cool down?
Post by: Sbrem on October 19, 2011, 08:36:10 AM
Ever since I can remember, yes. However, we have an old Cincinnati Red Demon in which the elements are quite high off the belt, and that one we shut the belt down at the same time. Same belt for the last 15 years or so, and it's in good shape.

Steve
Title: Re: Conveyor cool down?
Post by: mk162 on October 19, 2011, 08:37:26 AM
Ours keeps the blower running until it reaches around 250.  Then the belt keeps going.  I wish that shut off as well.  The dumb thing about our oven is there is no off switch.  I didn't realize at the time that is was an option.

So I installed a 3-phase disconnect box next to the oven control panel.
Title: Re: Conveyor cool down?
Post by: 244 on October 19, 2011, 09:50:46 AM
I have an Economax II. When I hit the stop button it turns off the panels while the belt continues to run. When it cools to 300, it shuts down completely. I have never had to replace a belt, but I imagine they are expensive. It takes about 12 minutes from the time I hit stop till it turns off. Yep, fans help.
All dryers made by M&R have an automatic cooldown system. On dryers larger than the Economax they also have a crank to turn the belt in case of power failure as well. This feature was added about two years ago. As an FYI the belt material should be fine up to around 550F. I would still run the conveyor just to be safe though.
Title: Re: Conveyor cool down?
Post by: Gilligan on October 19, 2011, 03:30:27 PM
I checked it this morning and I'm ok this time.

Obviously now I know and I will stick to my initial thoughts and let it cool down. :)

MK, if your belt motor is single phase then you could setup a delay timer to shut off after X time.  I have a few that I jacked "came across" in a compressor room for a large building AC unit. (they control the dampners for the duct work).
Title: Re: Conveyor cool down?
Post by: tpitman on October 19, 2011, 03:55:24 PM
With my cheap-azz dryer I turn off the heat and let it run for about 15 - 20 minutes to cool off. I leave the belt switch on all the time and shut it down at the breaker box so if there's juice going to the dryer, the belt is running. Not interested in buying a replacement.
Title: Re: Conveyor cool down?
Post by: sweetts on October 25, 2011, 07:34:27 PM
With my cheap-azz dryer I turn off the heat and let it run for about 15 - 20 minutes to cool off. I leave the belt switch on all the time and shut it down at the breaker box so if there's juice going to the dryer, the belt is running. Not interested in buying a replacement.

Man stick a switch on it, every time you cycle a breaker switch it reduces ever so slightly the tolerances of the breaker, it may be years but at some point that breaker will fail, a 20 dollar switch is much cheaper then burning up your shop if it fails.
Title: Re: Conveyor cool down?
Post by: ebscreen on October 25, 2011, 07:43:01 PM
Cycling breakers makes them trip at lower amp draw, meaning less likely to burn things, but more likely to
shut your shop down with everything going. Which then could burn things in the dryer if the belt
stops moving...
Title: Re: Conveyor cool down?
Post by: sweetts on October 25, 2011, 07:58:21 PM
Cycling breakers makes them trip at lower amp draw, meaning less likely to burn things, but more likely to
shut your shop down with everything going. Which then could burn things in the dryer if the belt
stops moving...

I was aways told that too, but back when I was in school for electronics we set up a test with varying loads up to and over the breakers rated amperage. The only breakers we were able to put a load on greater then 15% of rated amperage for a duration greater then 20 seconds were the breakers that we cycled more then 200 times. We used a new breaker as our base line. Do what you want but there is no reason in the world to use a breaker for a switch its just bad practice. I should say we also had cycled breakers pop sooner, the point is you can not  say with 100% certainty that it will open the circuit sooner in every case. I say why roll the dice.
Title: Re: Conveyor cool down?
Post by: Gabe on October 25, 2011, 08:02:39 PM
for those using the fan in order to cool down quicker
is not a good idea. it may cause the temperature probe to shatter due to drastic change from hot to cool
thus reducing it`s reading accuracy
Title: Re: Conveyor cool down?
Post by: tpitman on October 26, 2011, 06:28:33 AM
Cycling breakers makes them trip at lower amp draw, meaning less likely to burn things, but more likely to
shut your shop down with everything going. Which then could burn things in the dryer if the belt
stops moving...

I was aways told that too, but back when I was in school for electronics we set up a test with varying loads up to and over the breakers rated amperage. The only breakers we were able to put a load on greater then 15% of rated amperage for a duration greater then 20 seconds were the breakers that we cycled more then 200 times. We used a new breaker as our base line. Do what you want but there is no reason in the world to use a breaker for a switch its just bad practice. I should say we also had cycled breakers pop sooner, the point is you can not  say with 100% certainty that it will open the circuit sooner in every case. I say why roll the dice.

Well, then I'll start unplugging it. Thanks for the info.