Automatic Zone Control

Kiln Series

Zone Control

Many kilns have all elements controlled as one zone.
Often the elements are graded in power output from top to bottom to adjust for temperature uniformity due to greater heat losses at the top and bottom.

With unzoned kilns there is no way to adjust for varying load conditions.
Zone control does this automatically.
We do use element grading on some kilns like the School-Master kilns - but we believe zone control gives the user more control over the firing of the kiln and will provide a more even firing, especially in the long run.

As the elements age and change in power output (and they will do that at varying rates because of their different designs) the built in adjustment will change.

In most L&L sectional kilns (Easy-Fire, Jupiter and DaVinci), both manual and automatic, each section is a separate zone controlled by individual contactors or zone switches.
Either the automatic control automatically adjusts the zones or, in manual kilns, you can adjust the zones with input switches.
Most L&L Front-Loading kilns are also zoned from top to bottom.

The DynaTrol features Dynamic Zone Control.
It is like having three controls in one.
The DynaTrol separately measures temperatures in the bottom, middle and top of the kiln and automatically adjusts the heat output of three separate heating zones even as the kiln is heating up.
Kiln temperatures are automatically evened out to within 1/2 cone or better top to bottom.
There is no manual intervention with input switches.
There are separate thermocouples (heat sensors) and contactors (power controls) for each of the three zones.

L&L pioneered multi-zone control for manual kilns (in our Econo-Kiln line which preceded the Jupiter kilns) over 40 years ago.
Each 9" high section of the kiln is controlled by an infinitely variable input switch. These switches allow you to adjust the gradients in the kiln by reducing the amount of energy that flows to hotter sections.
Especially when used in conjunction with L&L's Tru-View Pyrometer system you can dynamically (in real time) control gradients to prevent uneven heating.
On smaller single phase Jupiter kilns these switches are the complete power control.
The alternate way manual kilns are controlled is with simple High-Medium-Low type switches. The High-Medium-Low switches are fine for controlling heating ramp rates but will not give you much control over the heat gradients in the kiln. This is how our Dura-Fire kilns are controlled.

L&L has many years of real-life experience with zone control.
We have built millions of dollars worth of high-tech multi-zone furnaces to heat treat superconductors, process optical glass and make aerospace parts. Several 200 cubic foot kilns we built have 27 zones and are accurate to within plus or minus 2°C. One of our multi-zone furnaces was used to calibrate all the furnaces at Corning Inc. - it was so accurate they had to measure it with chromatic glass, which is far more accurate than any thermocouple available.