10 



MASS. EXPERIMENT STATION BULLETIN 404 



the finished panels. Care should be taken that braces and cross pieces are meas- 

 ured and cut accurately because these pieces determine the inside dimensions of 

 the cabinet. When the panels are completed thej' are nailed together to form the 

 cabinet as illustrated. All nailing should be done through the board into a brace 

 or support. 



The legs should be of such length that the heat spreader is 6 inches above the 

 source of heat. On dehydfators to be used with wood or coal stoves the legs should 

 be made from spikes, pieces of piping, or scrap metal. 



In hanging the door, the hinges are screwed to the outside of the door panel 

 first, and after the door has been fitted into position the other butts of the hinges 

 are screwed to the left hand support so that the door fits tightly. 



The bottom dimensions of the cabinet should be checked before cutting the 

 heat spreader to insure proper fit. This piece is then nailed on or tightly wired 

 to the side and bottom braces. While there is I'ttle danger of fire if the cabinet 

 is properly constructed, as a safety measure the bottom braces and the lower six 

 inches of the side and back panels and door should be given a thorough coating, 

 inside and out, with a heavy sodium silicate (water-glass) solution or other fire- 

 proof material. 



The natural draft dehydrator is very similar in appearance to the cabinet 

 dryer described by the U. S. Department of Agriculture Bureau of Home Eco- 

 nomics (1942). Dimensions and structural details differ in several respects, 

 however, and a chimney of larger size Is employed. A chimney of the dimensions 

 given is necessary in order to produce sufficient draft for distribution of heat 

 in all parts of the cabinet. The air inlets on the sides are so placed and of such 

 size that practically uniform temperature Is maintained on all of the trays. 



TROWT PAJ?TITION 



false: top- 



INSlDE PARTITION 

 FALSE TOP BRACE. 



TOP BRACE. 

 (BACK) 



TKAV RUNWAYS 



FRONT BRACE. 



m 



SIDt BRACE 



FALSt TOP 



BRACt ON FAL5E BACK 



FRAME. (FAhJ MOUNTING) 



GUARD BRACE 



FALSE BACK 

 • BACK 



BOTTOM BRACE 



Figure 4-a. Detail of Forced Draft Dehydrator showing method of mounting fan and cross- 

 section view of cabinet 



