40 



BULLETIN 98, U. S. DEPARTMENT OF AGRICULTURE. 



17 illustrates a general arrangement of a plant of this character with 

 all the necessary accessories. 



OPERATING ABSORPTION MACHINE. 



To start. — (1) Start water circulating through machine; (2) start 

 brine pump, making sure that the brine is circulating through cooler; 



(3) turn steam on gradually (steam should never be shut off entirely) ; 



(4) open gas line between cooler and absorber; (5) open weak-liquor 

 valve, setting it at the usual running position; (6) start ammonia 

 pump; (7) when generator pressure is about that usually carried, open 

 valve in the dry gas line slowly, allowing the gas to enter the con- 

 denser; (8) open and set expansion valve. 



To stop. — (1) Close steam valve on generator almost entirely 

 (steam should never be shut off entirely); (2) close expansion valve; 

 (3) shut down ammonia pump; (4) close weak-liquor valve; (5) shut 



Fig. 17. — General arrangement of absorption refrigerating machine. 



off cooler and absorber gas line; (6) close valve in dry gas line to con- 

 denser; (7) shut down brine pump; (8) shut off water supply. 



The foregoing suggestions are of a general nature only and should 

 be considered as such. The purpose for which a plant is used and 

 the character of the trade supplied have considerable bearing on its 

 operation and management; consequently the engineer in charge 

 must determine on the best methods to employ in order to get the best 

 results. 



Figure 18 is intended to show, diagrammatically, the apparatus 

 which is common to both the compression and absorption systems 

 of refrigeration. As a matter of fact there are a number of accessories 

 required in both systems for their successful operation which are not 

 shown in the elementary diagram, as will be noted by referring to fig- 

 ures 14 and 17, which show the complete equipment of the two 

 systems. 



