REFRIGERATION 



59 



The ice bunker should be so placed and constructed that it 

 will cause circulation of the air in the refrigerator. This is done 

 by placing a tight board screen on one side of the bunker and 

 slats or cleats 'on the opposite side (Fig. 12). The air will then 

 enter the ice bunker from above the board screen and come in 

 contact with the ice. The moisture from the air unites with 

 the water melting away from the ice and is carried away with 

 it; the air, which thus becomes dryer and chilled by the ice, 

 descends through the open side of the bunker. If both sides 



Fig. 12. — Section showing perfect air circulation in an 

 ice bunker refrigerator. 



were open, the air would descend from both sides and thus 

 result in conflicting currents which would check the circulation. 

 The bottom of the ice box on the inside is covered with gal- 

 vanized iron sheeting turned up on the waUs of the box from 

 4 to 6 inches. From this galvanized pan a galvanized iron pipe 

 carries the water away. This water may be collected outside 

 of the refrigerator and, if the ice is clear, may be used for testing 

 and other laboratory purposes. The pipe carrying water from 

 the ice pan should be equipped with a trap to prevent com- 

 munication of air between the refrigerator and the outside. 

 The bottom of the ice box should be insulated on the outside 

 and the ends of the box tightly boarded up. 



