Can Inline MC Data be used to find "Cold Spots" in Kilns?

[JMS]

How can inline moisture measurement data be used to characterize "cold spots" in a kiln?   

I would appreciate any feedback. 

Thanks

[TimothyD]

How can inline moisture measurement data be used to characterize "cold spots" in a kiln?   

I would appreciate any feedback. 

Thanks

Hi JMS,

"Cold spots" in a kiln are characterized by a larger than "typical" or "normal" standard deviation.  If one's standard deviation of moisture content determined at the planer for a particular charge of lumber from a kiln has increased significantly, then one possibility is that the kiln may have developed a "cold spot", especially if the incoming lumber diet has not changed.

In order to detect this occurrence, one must be tracking the moisture content at the planer inline moisture measurement system on a "charge by charge" basis.  This is easily done with one of our systems; even if the packages coming in are not sequential from the same kiln or kiln charge, our tracking software can manage and segregate the data appropriately.  Comparing previous charge standard deviations from a baseline to current standard deviations will help easily identify when something is amiss.

Taking this one step further to aid in fault identification, one can track the location of each package in the kiln charge for multiple charges (3-5) and average the average MC of those 3-5 packages for each location, then compare these averages for all 3-5 charges to determine where inside the kiln the "cold spot" actually is located. This will greatly help in taking steps to either "fix" a critical system within the kiln, or modifying operational steps to further improve overall kiln charge variability.

Since running 3-5 charges through an under-performing kiln resuts in loss of opportunity cost, we recommend a regimented program where this type of analyses are performed on a continual basis; doing so creates a program that identifies drying issues in as fast a manner as possible and allows for a minimal of delay in fault identification and resolution.

Great question!

[JMS]

Timothy,

Thank you for this very helpful information.  I appreciate the feedback.
JMS 

[GeorgeCulp]

Sorry to be so late to the party on this one but Timothy is absolutely dead on with what he is saying.

Yet, I will expand for a momnet on what he said above...

What you can learn from operating an inline meter system and in the way he describes gives you information that you cannont possibly get otherwise. You learn how widths dry differently, how lengths dry differently, etc. Which in turn will indicate how to mix and match your loads. And it will tell you where your "cold" spots are.

Think of it this way.... the inline system will show you how to eliminate and/or minimze variables in your drying... and that is the key to maximizing your drying quality.