292 MANUFACTURE OF MiiK PowpkEr 
the solid constituents of liquids, such as blood, milk and the like, in 
the form of powder, said process consisting in converting the liquid 
into a fine spray, bringing such spray or atomized liquid into a reg- 
ulated current of heated air, so that the liquid constituents are com- 
pletely vaporized, conveying the dry powder into a suitable collect- 
ing space away from the air current, and discharging the air and 
vapor separately from the dry powder.” 
The Stauf patent shows a vertical drying chamber (e) into 
which the liquid (milk) to be desiccated is atomized through jets 
or nozzles (b) under pressure, into a fine spray. A current of 
heated air is admitted at the bottom of the drying chamber (f) run- 
ning in the same direction as, and mixing with, the spray of milk, 
and evaporating the watery constituents of the spray. The steam 
and dried particles are carried upward by the heated air, retaining 
the atoms momentarily in the current of hot air and causing them 
to surrender substantially all the remaining moisture in the form of 
vapor, and the product is prevented by the cooling effect of such 
evaporation from undergoing chemical change. The vapors and 
dried atoms are guided by a cone (g) extending downward from the 
top into the drying chamber, into collecting chambers (h) where the 
desiccated milk or dry powder gathers in hoppers (1) away from 
the vaporizing current. The moisture-laden air or gas is separated 
from the dry powder and escapes through the sides of the collecting 
chamber, which consist of mill gauze, woolen fabric or like pervious 
material. 
The McLachlan Process.—T'his process was patented by 
John C. McLachlan of Chicago, Ill., U. S. patent No. 806,747, De- 
cember 5, 1905. This process is a modification of the Stauf process. 
McLachlan uses a tall vertical drying chamber (B) surrounded 
on its sides by a jacket or casing (A), containing steam heating coils 
(G) with intake, and outlet of steam; a circular, perforated pipe 
(M) is installed near the top of the chamber for the purpose of dis- 
charging into the chamber heated air, an atomizing jet (O*) enters 
through the side of the drying chamber near the top, an air pump 
(O) forcing heated air into the atomizing nozzle (O*), a slide door 
(D) at the bottom of the drying chamber for the discharge of the 
dried powder through opening (FE), and a perforated covering (K) 
over the top of the drying chamber for the escape of the moisture- 
laden air. 
