cropped graphic of kiln showing air flow

  Geil's Innovative Downdraft Firing System

 
The original GEIL Downdraft Design was created in 1971 by owner, Paul H. Geil, and has since been refined and improved upon without alteration to the basic design.
 
The basic design features:
  • Elimination of all deflection devices characteristic of other kiln designs
  • Multi-directional downdraft circulation
  • High velocity, natural draft, Venturi burners
  • Precise atmosphere control
  • Even temperature distribution throughout the kiln chamber
The GEIL Downdraft Patented Design differentiates itself from other kiln designs with its unique placement of the burners in relation to the draft.
 
Standard Downdraft Kilns
The standard relation of the burners to a downdraft-type system utilizes a horizontal placement of the burners, thereby necessitating the use of deflection devices, such as bagwalls, to deflect the heat flow upward. This deflection drastically reduces the velocity at which the heat enters the chamber, therefore a high flue is necessary in order to pull the atmosphere through the kiln. (figure 1)
  
Standard Updraft Kilns
The vertical placement of the burners commonly found in updraft design requires the deflection of heat energy outward and upward through the use of hearth slabs.
The updraft kiln has the flue opening at the top of the kiln and does not pull the atmosphere down through the center. The heat travels in only one direction-up and out the flue. This produces very little circulation and wastes valuable heat energy. (figure 2)

Standard Downdraft Kilns
Image Diagram 1 Front View Cutaway showing how bagwalls waste space and energy
Figure 1
Front view cutaway
 

Standard Updraft Kilns
Image Diagram 2 Front View Cutaway showing how Hearth slabs waste space and energy
Figure 2
Front view cutaway
The Geil Downdraft design
The GEIL Downdraft System utilizes heat energy to its fullest potential through recirculation. This, of course, means energy savings and consistently superior results in firing. In contrast to other kiln designs the GEIL Design ingeniously allows for the elimination of all such deflection devices through the vertical positioning of the burners within the framework of a downdraft design. (figure 3)
Deflection devices simply absorb valuable heat energy and obstruct the direct transfer of heat to the setting. The elimination of deflection devices produces an unobstructed, multi-directional heat flow or circulation within the kiln chamber which conserves fuel, produces excellent firing results and offers more available combustion area.
Combustion areas running the entire length of the side walls insure a proper oxygen to gas ratio, necessary for complete combustion to occur. The occurrence of combustion heats the kiln's atmosphere. The kiln's heated atmosphere rises and is drawn downward by the action of the flue. The flue opening is centered in the rear wall directly over the kiln floor and serves to create the necessary vacuum to pull the atmosphere downward through the setting. Precise atmosphere distributions are easily achieved through the adjustment of the damper and the main gas valve controlling the burners.

The Geil Downdraft design
Image Diagram 3 Front View Cutaway showing Geil Downdraft design
Figure 3
Front view cutaway