AN IMPROVED MODE OF EXTRACTING OILS FROM COAL OR OTHER BITUMINOUS SUBSTANCES YIELDING HYDROCARBON OILS
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Charles George Lundborg at the
Office of the Commissioners of Patents, with his Petition, on the
26th August 1864.
1, CHARLES GEORGE LUNDBORG, of Sodertelje, in the Kingdom of Sweden,
Paraffin Oil Maker, do hereby declare the nature of the said Invention for
"AN IMPROVED MODE OF EXTRACTING OILS FROM COAL OR OTHER BITUMINOUS
SUBSTANCES YIELDING HYDROCARBON OILS," to be as follows:-
In manufacturing oil from the above substances by destructive distillation
it is of the utmost importance that the distillation should take place with a
low and even degree of temperature barely sufficient to develope the oleagi-
nous vapours, while a too high degree of heat converts a portion of the oily
vapours into permanent gases, thus diminishing and deteriorating the product.
The rotary retort has been found most suitable for the purpose, making dis-
tillation practicable with a less degree of heat than must be used with a
stationary retort. But in using the revolving retort it will be found that the
residuum of the bitumen or material used leaves a coating on the interior sides
of the retort, which coating gradually increases with every charge, and being
a poor conductor of heat, makes a higher exterior temperature necessary, with
every charge, while a portion of the oily matter remains on the coating, and
is there burned and converted into permanent gases. In order to get the
best and largest product from the material used, it will therefore be found
necessary to clean the retort for every charge, which in the ordinary way.

page_text: can be done only when the retort is cooled down, so as to permit a person
entering it.
The present Invention is to prevent or greatly diminish the cooling alluded
to, so that a great number of charges may be run without any cleaning or
stopping the work, while at the same time a much larger yield and a better
quality of oil is obtained, and the heat is distributed more equally in the
retort. I obtain the desired result of keeping down the coating and distri-
buting the heat by introducing a certain quantity of pieces of iron or hard
stones with the coal or bitumen into the retort. The loose iron or stone will
by its specific gravity follow the bottom of the retort (which may be ribbed in
the interior surface) during its revolutions, rapidly acquiring the temperature
of the surrounding surface exposed to the fire, and being mixed with the coal
or bitumen, which by the rolling action of the pieces of iron or hard stones
is crushed into small fragments, the beat is diffused more equally through the
mass, and the adherence of the coating before alluded to almost pre-
vented. The yield of oil by this process is much increased, and its quality
greatly improved. I use pieces of iron or granite stones weighing from one
to five pounds each, and put generally about two hundredweight to a charge
of two thousand pounds of coal. The quantity of loose iron or stones used
or the weight of the separate pieces may, however, be more or less, according
to the nature of the coal or bituminous material used, and I do not see any
reason why pieces of some other metal than iron, or any other, kind of hard
and heavy substances, may not suit equally well.