42 College of Forestry 



Ovens. 



The oven or oven retort is a vast improvement over the 

 round retort, the chief advantages being that a large amount 

 of Avood can be distilled at one time and considerable labor is 

 saved in charging and discharging the ovens, the loaded wood 

 cars being run directly in from one end on tracks and hauled 

 out by means of a cable on the other end to the first cooling 

 oven. 



These ovens in cross section are feet 3 inches wide and 

 8 feet 4 inches high. In length thev varv from 25 feet to 

 50 feet, although the usual length used at the present time 

 is a 52-foot oven which holds 4 cars. These ovens are usually 

 installed in batteries, that is, 2 ovens ])eing placed close 

 together and called a battery. In Michigan there are as many 

 as 7 to 10 batteries in a single plant. The largest New 

 York plant contains 8 ovens and is located at Corbett in 

 Delaware county. Altogether in Xew York State there are 

 46 ovens distributed over 10 plants. 



These ovens have air-tight doors on one or both ends, 

 depending upon whether the charcoal is to be taken out in 

 the same direction as it entered or sent out through the pro- 

 gressive form of trackage arrangement. The ovens are of 

 steel, usually three-eighths of an inch in thickness, while the 

 bottoms and backs are of one-half inch material. The oven 

 is sustained by means of angle irons riveted perpendicularly 

 on the sides and on one side near the top are riveted cast iron 

 nozzles, usually two in number, which are attached to the 

 condensers. In the heating process it is said that the 52-foot 

 oven will expand 4 inches in length due to the tremendous 

 heat applied during distillation. These ovens only last from 

 3 to 12 years, so that the depreciation charge is very high. 



The 52-foot oven costs about $1,800 and approximately 

 an equal amount is required to install and set it up ready 

 for operation. 



