IMPROVEMENTS IN THE DISTILLATION OF COAL TAR AND IN THE APPARATUS EMPLOYED THEREIN."
Year: 1880

page_text: LETTERS PATENT to George William Davey, F.C.S.A.I.C., Manufacturing and
Analytical Chemist, of Barking, in the County of Essex, for an Invention of
"IMPROVEMENTS IN THE DISTILLATION OF COAL TAR AND IN THE APPARATUS
EMPLOYED THEREIN."
PROVISIONAL SPECIFICATION left by the said George William Davey at the
Office of the Commissioners of Patents on the 29th June 1880.
GEORGE WILLIAM DAVEY, F.C.S.A.I.C., Manufacturing and Analytical Chemist,
of Barking, in the County of Essex. "IMPROVEMENTS IN THE DISTILLATION OF
COAL TAR AND IN THE APPARATUS EMPLOYED THEREIN."
This Invention has for its object to employ hot air in the distillation of coal tar,
whereby I obtain, 1stly, a greatly increased product; 2ndly, the coking of the pitch
in the bottom of the still is entirely prevented; 3rdly, provision is made for the
immediate expulsion of the vapour from the products when they reach their true
distilling points; 4thly, it allows of any kind of fuel being used during the entire
process of distillation; and 5thly, it effects a great economy both in the time
occupied and in the amount of fuel consumed in the operation.
To carry out my Invention I heat the still with fire, and at the same time as
the distillation proceeds I inject hot air into the still, and continue the supply of
such hot air until the distillation is completed, at the same time keeping a small
fire beneath the still.
I inject the hot air into the still by means of a pipe, which traverses nearly to
the bottom of the still, where it branches off into a number of smaller pipes, which
are perforated so as to allow of the hot air (which is drawn from an adjacent
furnace or other convenient source) escaping and diffusing itself through the coal
tar under treatment.
By this improved process the still can be worked off with a far greater saving of
time and fuel than by any other process hitherto in use; at the same time that tho
carbonisation of the pitch at the bottom of the still is entirely prevented, and a
greatly increased yield of valuable product is obtained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
tho said George William Davey in the Great Seal Patent Office on the 29th
December 1880.
GEORGE WILLIAM DAVEY, F.C.S.A.I.C., Manufacturing and Analytical Chemist,
of Barking, in the County of Essex. "IMPROVEMENTS IN THE DISTILLATION OF
COAL TAR AND IN THE APPARATUS EMPLOYED THEREIN.”
This Invention has for its object to employ hot air in the distillation of coal tar,
whereby I obtain, firstly, a greatly increased product; secondly, the coking of the
pitch in the bottom of the still is entirely prevented; thirdly, provision is made
for the immediato expulsion of the vapour from the products when they reach
their truo distilling points; fourthly, it allows of any kind of fuel being used
during the entire process of distillation; and, fifthly, it effects a great economy
both in the time occupied and in the amount of fuel consumed in the operation.
To carry out my Invention I heat the still with fire, and at the same time as
the distillation proceeds I inject hot air into the still, and continue to increase the
supply of such hot air until the distillation is completed, at the same time keeping
a small fire beneath the still I inject the hot air into the still by means of a pipe,
which traverses nearly to the bottom of the still, where it branches off into a
number of smaller pipes, which are perforated so as to allow of the hot air (which
is drawn from an adjacent furnace or other convenient source) escaping and
diffusing itself through the coal tar under treatment.
By this improved process the still can be worked off with a far greater saving
of time and fuel than by. any other process hitherto in use; at the same time that
the carbonisation of the pitch at the bottom of the still is entirely prevented, and
a greatly increased yield of valuablo products is obtained.
In the distillation of coal tar as carried out up to the present time the heat
generally employed for this purpose is ordinary fire heat or steam, but I find a
much greater quantity of product can be realized by my present Invention, while
1 prevent thereby the coking of the pitch in the bottom of the still, and provide
for the immediate expulsion of the vapcur from the products when they reach a
their true distilling points. Another great advantage of my Invention is that any
kind of fuel can be used during the entire operation of distillation.
And in order that my said Invention may be better understood and readily
carried into effect, I will now, with the aid of the accompanying Drawings, proceed
to particularly describe the parts in connection with a still constructed for carrying
out my improved method of distillation.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shews' a vertical, and Figure 2 a horizontal section of a still arranged
to carry my improved method of distillation of coal tar into effect. In both these
Figures similar letters of reference_indicate corresponding parts. As already
mentioned, in order to carry out my Invention 1 employ hot air at a convenient
pressure and temperature.
The still being heated by fire the hot air is at once passed into it by a cock A
traversing a pipe B into the branches C, C, which branches are perforated, and so
subdivided as to strike upon the crown and ultimately reach the outlet D, striking 4

page_text: steam has been used in the distillation of coal tar, but what I claim as my Invention
is, the distillation of coal tar by means of hot air passed into a still, constructed as
bereinbefore described and illustrated, at a low pressure and temperature through
the coal tar or pitch under operation, in manner and for the purposes hereinbefore
set forth and described.
In witness whereof, I, the said George William Davey, have hereunto set my
hand and seal, this Twenty-ninth day of December, in the year of our
Lord One thousand eight hundred and eighty.