"Dryer bars", also called "Spoiler bars" consist of a number of equally-spaced rows of steel bars that are held against the inside surface of the dryer shell.
These bars are about 10 mm x 20 mm in cross-section. There will be 15 to 36 rows of these bars extending from one end of the dryer shell to the other. These bars, if properly spaced, will produce resonant oscillation in the rimming condensate in the dryer. This greatly increases the rate of heat transfer from the steam to the dryer shell in dryers that have rimming condensate. This increase in heat transfer rate can be used to reduce the operating steam pressure to the dryers or to increase the drying capacity of the machine.
The dryer bars also improve the cross-directional uniformity of the dryer surface temperature, providing a more uniform reel moisture.
Dryer bars manufactured by Kadant Johnson (Turbulator® bars) use stainless steel tubes rather than steel bars. Stainless steel bars do not corrode and tube bars can be larger in cross-section with less weight, making the cost lower and the installation much easier.