e absorber, which would become heated by the liberation of
heat due to the absorption and consequent liquefaction of the ammonia
vapor, is still further cooled by the circulation of cold water. As
the pressure in the absorber is much lower than that in the generator,
the strong liquor has to be pumped into the latter vessel, and for
this purpose pumps are provided. Though of necessity the various
operations have been described separately, the process is a continuous
one, strong liquor from the absorber being constantly pumped into the
generator through the heater or economizer, while nearly anhydrous
liquid ammonia is being continually formed in the condenser, then
evaporated in the refrigerator and absorbed by the cool weak liquor
passing through the absorber.

Putting aside the effect of losses from radiation, etc., all the heat
expended in the generator will be taken up by the water passing
through the condenser, less that portion due to the condensation of
the water vapor in the analyzer, and plus the amount due to the
difference between the temperature of the liquid as it enters the
generator and the temperature at which it leaves the condenser. In the
refrigerator the liquid ammonia, in becoming vaporized, will take up
the precise quantity of heat that was given off during its cooling and
liquefaction in the condenser, plus the amount due to the difference
in heat of vaporization, owing to the lower pressure at which the
change of state takes place in the refrigerator, and less the small
amount due to the difference in temperature between the vapor entering
the condenser and that leaving the refrigerator, less also the amount
necessary to cool the liquid ammonia to the refrigerator temperature.
When the vapor enters into solution with the weak liquor in the
absorber, the heat taken up in the refrigerator is imparted to the
cooling water, subject also to corrections for differences of pressure
and temperature. The sources of loss in such an apparatus are:

a. Radiation and conduction of heat from all vessels and pipes above
normal temperature, which can, to a large extent, be prevented by
lagging.

b. Conduction of heat from without into all vessels and pipes that are
below normal temperature, which can also to a large extent be
prevented by lagging.

c. Inefficiency of economizer, by reason of which heat obtained by the
expenditure of steam in the generator is passed on to the absorber and
there uselessly imp