Ammonia Machines.
—The use of ammonia refrigeration equipment either absorption or compression has so generally displaced all others for stationary or land use, and particularly in meat plants and cold storage houses, that for the present purpose it is unnecessary to go into a discussion of others. The compression system being so predominant in its use, a description of same is given.
The [diagram] indicates a compression system in elementary form consisting of:
(1) A pump or compressor which withdraws the gas from the cooler or expansion tank, prepares and passes it to the condenser.
(2) The condenser or liquifier which gives to the water flowing over it the heat carried to it by the gas from the cooler.
(3) The cooler or expansion tank in which the heat extracted from the carcasses, the building walls or elsewhere, is passed to the ammonia gas for conveyance to the condenser.
Ammonia.
—Leaving for a moment the description of the apparatus to acquaint the reader with ammonia: In the form used in a compression refrigerating machine, it bears the name “liquid anhydrous ammonia” meaning in a “dry liquid” form differentiating from the common household ammonia which is a water solution containing ammonia gas in variable quantity. The distinction between these two is that “anhydrous ammonia” will evaporate to naught; from household ammonia the gas will evaporate but the water will remain.
FIG. 15.—DIAGRAM SHOWING AMMONIA COMPRESSION SYSTEM.