speed control based on moisture

[hounddog]

I also posted this in another forum, but realize that there are folks who use this forum that may not use that forum, so hopefullys someone may have tried something like this.

Have a question that I hope someone may have a good answer to. Have a machine that is a dryer that fabric is feeding through at speeds from 0 to about 70 yards per minute. We have been brainstorming about would it be possible to have the fabric as it exits the dryer run across some type of sensor that would measure the moisture in the sensor and also have some type of infrared temperature sensor to detect the temp of the fabric as it exits. Based on the moisture and the temp. determine how fast to run the fabric. For example, you enter a set point to run 40 yards per minute and maintain a moisture of 4%. and use the signals from the sensor to control a pid that would be used to tune the setpoint, plus or minus a percentage of the speed setpoint to maintain the 4% moisture. Does this sound something that would be possible, and if so, any suggestions, ideas would be greatly appreciated. Thanks

 

[JRW]

That's been done for years.
Is this a tenter frame?

 

[hounddog]

no, it is a fabric dryer, cloth feeds through the front of the dryer, which is about 70 feet long, then exits out the end and is stacked to be used in another process.

 

[jrwb4gbm]

Just one company among many that does this for paper and textiles:
http://www.mahloamerica.com/paper/qms.html

And another for cotton ginning:
http://www.moisturemirror.com/

 

[Gil47]

This is a product we have on site that appears to do as you are describing.

In fact the photo could be from our site

http://www.streatsahead.com/Pages/Drycom Menu.html

 

[JRW]

Hounddog

Your description in your first post will work fine.
I've worked on similar machines and that's how we
Did it too. We also did a dwell time control with pyrometers.
(Like the Mahlo system, but not as nice
It may take some time to tune though.
Keep us posted!

 

[hounddog]

Thanks for info, have some meetings,(brainstorming) this week, would it be possible to maybe post a sample of anything that any of you may have tried in the past. I done quite a few projects where I tell a motor to run a set speed, then use a dancer analog sensor to trim that speed by a percentage, took a quite a bit of testing to determine what percentage range, but speeds where only around 20 ypm, this will be 0 to about 70 yards per minute,
Thanks

 

[DWF]

When I worked in textiles, we had moisture monitor systems by Strandberg on all of our West Point slashers.

Here is their website.

http://www.strandberg.com/

 

[hounddog]

When I worked in textiles, we had moisture monitor systems by Strandberg on all of our West Point slashers.

Here is their website.

http://www.strandberg.com/

Thanks, actually found them after doing a lot of searching on the net today. What was the cost? Also, did you use the sensor and feed it back into a plc, or did you use the meter with the sensor? Looks like a very good product, almost identical to what our managers wants to try and build, heck, looks like these guys have already done all the home work. Like the looks of it.