234 TRANSACTIONS OF THE 
driving the ratchet wheels, and thereby the rate of dis- 
charge, being controllable at will. 
“The discharge mechanism drops the shale into the 
(5) spent shale hopper, into which exhaust steam is 
passed, and as the hoppers fill, the spent shale is dis- 
charge into cars which carry it to spent shale dumps or 
‘bings’. No practical use has ever been found for spent 
shale in Scotland. 
‘Shale feeds continually from the fresh shale hopper 
into the cast iron part of the retort, and in this part the 
bulk of the oil is distilled, at a temperature of about 
900° F. Descending, the shale, in the brick part of the 
retort, gradually heats up until at the bottom of the 
retort its temperature may reach 1500° to 1800° F.” 
In Scotland, large quantities of steam are used in the 
oil-shale retorting process but accurate data are not avail- 
able regarding the percentage of the steam decomposed 
during its passage through the retorts. 
“The exact chemical role of the stexm in producing 
increased ammonia recovery and oil of better quality is 
not definitely known. The following purposes,’ however, 
are fairly definitely established and agreed upon in the 
use of steam: (1) to reduce the temperature of the spent 
shale at the bottom of the retort; (2) to carry the heat, 
which has been recovered from the spent shale up into 
the retort, in the form of superheated steam; (3) to form 
water-gas from the fixed carbon remaining in the shale; 
(4) to aid in the recovery of ammonia from the shale; (5) 
to add greater volume to the oil vapors, thereby giving 
them a greater velocity in the retort and causing them 
to be swept out of the hot zone of distillation, preventing 
their further decomposition to a large extent; (6) de- 
creasing the partial vapor pressure of the heavier hydro- 
carbons and allowing them to be vaporized or removed 
at a lower temperature; and (7) to counteract, by con- 
vection, the poor thermal conductivity of the shale, 
thereby allowing a better transfer of heat from the walls 
of the retort to the center of the shale column.” 
‘Jakowsky, J. J., Uses and Supply of Water for the Oil-Shale 
Industry: Unpublished manuscript. The remainder of this paper 
has been abstracted from this manuscript. 
