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Heating 1meter copper tubes for textile finishing 3

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Sunflame

Sunflame

Industrial
Sep 17, 2018
9
Dear Engineers!
I would like to heat two copper tubes 1 meter long each to about 200 celsius degrees for a textile finishing application.
The tube's diameter is 35mm, thickness is 1,5mm and an electric heater 300mm long is placed inside the tube on one side or both.
As copper is a good heat conductor, do you think I will be able to maintain around 180 degrees celsius in the middle of the tubes?
 
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It depends on what the heat loss is (what are you heating?), power of the heaters, and how they are mounted inside of the tube.
At first look I would doubt that this will have a uniform surface temp.
How will the heaters be coupled to the tube?


= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
 
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You offer so few details that I doubt you will have much success, as you seem to have a very rudimentary understanding of your problem. Try describing what you are trying to do with your "textile".
 
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"middle of the tubes?"

what is that? an inch, a foot? If inch, then sure, that's doable. If foot, that's getting iffy, given that your heater is only about 12 inches long

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
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Kudos for the quick replies.
Okay sone more details below.
The heaters are 1500w each basically in contact with the copper tube. The heaters are capable of reaching 200 celsius degrees on their own.
For our application we have to melt low melt polyester fibres in a mix nonwoven web compressed to 1mm thickness passing through these heated rollers.
Sometimes we use ldpe or PE fibres with melting point around 180 degrees celsius.
So the textile web touches the rollers and is quite thin, and it may be useful to reach higher than 110 degrees celsius in order to maintain the required production speed (around 8 meter/min passing through these heated rollers)
 
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How much heat is needed to do this to 1 linear meter of web?
What is the speed of the web?
 
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110 celsius degrees at least, probably more would be useful because of the speed which is 8 meter per minute.
 
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Heat is different from temperature.

How much heat do you need?

You state that the heaters are 1500 w. It's not clear how many heaters you envision. I read you posts as a maximum of 4.

For reference, 1500 w looks like this.
180px-Hairdryer_20101109.jpg


Do you think four of these will do the job?
 
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Well yes, basically it is my question, whether four heaters with 1500w are enough to maintain the temperature, if the copper tubes "touches" the heater's surface which is 200 celsius, as copper is a good conductor of heat.
 
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Workingh width is 1 meter. Heat difference on the tube is not a problem, but ideally it reaches 180 degrees celius even onm the farthest parts from the heater.
 
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And to answer that question it is necessary to know how much heat the process requires, which we have asked several times so far.

Or we could guess.

My guess is no.

IRstuff is better at heat transfer than me, so his guess will probably be more reliable.
 
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The web is 200 gramm/square meter, that is 200 kg/m3, it may change the equation to our favor?
 
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Non-woven web of fibers of unknown size compressed to 1 mm from an unknown uncompressed thickness and may contain other unknown fibers.

I guess that your density and specific heat values just might be a bit off.

On the other hand, it's possible that the web is warmer when it enters.
 
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It means that you probably need more than 2 heaters, and it means you now have to deal with non-uniformity of the heating, due to losses to the material and losses to the air, etc.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
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The main heat load in your process is the heat your textile web will absorb. This is what IRstuff calculated for you. You are nowhere close to working. And there are many more details to consider, such as temperature uniformity and process starts and stops. Get some help from your work colleagues or supervisor. This tube is actually a roller?
 
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Fibres are polyester/cotton mix all passing tearing drums, with average denier 1,7 (gram/9000 meter). To reach 1mm thickness the web is compressed from a 10mm thickness batt so most of the air is gone.

Maybe we can pre-heat the web with infra heaters before entering these heated rollers
 
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