S e r v i c e s

Dynamic Heat Balancing

 

Improve Your Lumber Quality Today!

 

Why Heat Balance?

The volume of air from the top fans per second and the volume of air coming from the heat duct openings per second changes through the course of a year from many varying factors. The following is a list of a few.

  • Condition of the kiln structure and panels.
  • Condition and efficiency of baffles.
  • Variations in air velocity.
  • Reliability of utilities (electricity, fuel).
  • Preventive maintenance and emergency repairs.

 

Note: Heat Balancing should be done once a year for maximum efficiency.

 

What does Heat Balancing do for the drying process?

A properly balanced dry kiln will improve drying quality.  The heat will be evenly dispersed throughout the dry kiln providing better final moisture content distribution from end to end. It takes an equal amount of energy too dry two pieces of wood equal in dimension and MC down to the same MC. Energy cannot be created or destroyed it can only be transformed. In order to dry lumber evenly along the length of a Kiln the heat duct openings must release an equal amount of energy in the form of heat. This heat can be measured in degrees. Heat balancing scientifically makes the energy down the length of the Kiln equal with in reason. Having an equal amount of energy along the length of a charge obviously evens out the drying.

 

Heat Balancing Process

        The Kiln must start with a wet charge. A total of 60 digital temperature devices are placed on the sides of a charge from one end to the other. 20 on Side 1, Side 2, and the Center.

The following 6 steps are repeated when the Kiln is at low temperature (below 80 F) as many times as it takes to balance the kiln usually 3 or 4 times.

        The blower, heat fan, and burner are started manually.

        The kiln fans are started manually in forward.

        Temperatures in the kiln are read in with the laptop.

        The kiln fans are stopped and then started in reverse.

        Temperatures in the kiln are read in with the laptop.

        Readings of both fan directions are graphed and adjustments to the ducts are done accordingly.

        The kiln is then fired up in auto mode to dry the lumber.

        More readings are taken to monitor the Kiln at high temperature.

        Fine-tuning of the kiln is done if needed.

        Finally if no more adjustments are needed a report and set of graphs are made for the customer.

Note: Sometimes this entire process is repeated if the Kiln shows at high temperature that it needs major adjusting.

How Adjustments Are Determined?

The temperatures in the kiln are graphed using Excel allowing us to find the hot and cool spots in the Kiln. The graph shows the temperature of the Kiln on both Sides and the Center from one End to the other. Knowing the location of the temperature devices the heat duct openings are open or closed to balance out the temperatures from one end to the other. When balancing it is important to not only look at the temperatures on the sides. The center gives the best reading of the pressure in the heat duct from end to end.

 

 

Frank Controls will heat balance all gas-fired kilns regardless of the type of kiln control drying your lumber. We have got heat balancing down to an art. What are you waiting for improve your lumber quality and save money today. Contact us at sales@frankcontrols.com or 1-250-765-2900.