Improvements in the Destructive Distillation of Mineral Oils and in Apparatus therefor.
Year: 1890

page_text: Date of Application, 17th Mar., 1890
Complete Specification Left, 13th Dec., 1890-Accepted, 7th Feb.,
1891
PROVISIONAL SPECIFICATION.
Improvements in the Destructive Distillation of Mineral Oils and
in Apparatus therefor.
I, JOHN LAING of 34 East Preston Street Edinburgh, Scotland, Analytical and
Consulting Chemist, do hereby declare the nature of this invention to be as
follows
The invention relates to the treatment of mineral oils by destructive distillation
at or near atmospheric pressure and so to convert them into lighter products.
The invention consists of dividing a boiler still into compartments from above
downwards to within sixteen inches off the bottom so that a man will have sufficient
room to enter from one compartment to another for cleaning or repairing purposes.
On the top of the still an arrangement is fitted up so that the gases in one compart-
ment pass over, get condensed and the liquid falls into the next compartment, and
so on through the series of connections till ultimately they leave the still by the
swan-neck outlet at opposite end of still, and are there conveyed to the general
condenser, or worm tank, connected with the oil receiving tank.
The condensers on the top of the still are surrounded with water jackets, the
inlet for cold water being at bottom of the jackets, and the overflow for the warm
water being at the top of said jackets. The warm water may be led into a common
receiving tank used for feeding a steam boiler.
If
On distilling the oil by this method no steam, on any account, is to be let into, or
used in, the still, as this would prevent the efficient breaking up of the oil.
the still is being fed continuously great care must be taken that the oil is dry, i.e.,
that it holds no water in it.
On heating up the still, the greatest heat is to be at the end opposite to the
swan-neck ontlet, and to be regulated so that there is just sufficient heat at the
opposite end as will distil the oil in that compartment.
I also place a stricture valve on the swan-neck outlet so as to regulate the delivery
of the gases from the still by reducing or increasing the area of the opening inside
the swan-neck outlet.
The contents of the still can be distilled off to pitch, and it here run off, or it can
be removed to other suitable apparatus and there dealt with in the usual way.
I do not bind myself to the number of condensers to be fixed on each still, that
being always regulated by the size of the still and the quantity of oil to be distilled;
nor do I bind myself to the form of condenser, whether I use a series of plates, or
perforated trays, or a worm coil.
Dated this Fifteenth day of March 1890.
JNO. LAING,
Applicant.
COMPLETE SPECIFICATION.
Improvements in the Destructive Distillation of Mineral Oils and in
Apparatus therefor.
I, JOHN LAING, of 34 East Preston Street, Edinburgh, Scotland, Analytical and
Consulting Chemist, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :-
My said invention relates to the treatment of mineral oils by destructive distillation
at or near atmospheric pressure, and has for its object the satisfactory and

page_text: economical decomposition or conversion of comparatively heavy mineral oils, and the
obtainment from them of lighter products.
In carrying out my invention I subject the oils to repeated distillation in a
practically continuous manner, in a boiler still which may be of a horizontal
cylindrical or other convenient form and which is divided into compartments by
partitions which are open at their bottoms. The vapors rising from the first
compartment are condensed and led into the second compartment; and the vapors
from the second and each succeeding compartment are similarly condensed and led
to each further compartment.
And in order that my said invention, and the manner of performing the same may
be properly understood, hereunto append a sheet of explanatory drawings to be
hereinafter referred to, and representing by way of example.a modification of my
improved apparatus.
Figures, 1, and 2, of the drawings are respectively a transverse vertical section
and a longitudinal vertical section of the apparatus.
In these drawings the same reference letters are used to mark the same or like
parts wherever they are repeated, two or more similar parts being in some cases
distinguished by numerals combined with the letters.
The distilling vessel is in the form of a horizontal cylindrical boiler, A, which is
internally divided into compartments, B1, B2, B3, B4, by vertical partitions, C,
which are open at the bottom to allow of free communication of the liquid oil
through all the compartments, the openings or spaces beneath the partitions being,
by preference, large enough to allow of access for cleaning purposes to all the
compartments. The boiler, A, is set in brickwork and is heated by means of any
suitable fuel in a furnace, D, at one end beneath the first compartment, B1, the
fire gases proceeding along a flue, E, extending under the middle of the boiler to
the other end, and there communicating by side ports, F, with return flues, G, at
the sides of the boiler. The return flues, G, communicate at their front ends, by
descending flues, with a horizontal flue, H, which may pass under a number of boilers
to a chimney. Additional ports, J, form communications between the bottom
flue, E, and the side flues, G, these ports, J, being fitted with adjustable dampers
by means of which the heat acting on the after parts of the boiler may be more or
less moderated if required, the fire gases tending to take the nearer route to the
chimney through the ports, J, when their dampers are open. The end ports, F,
may also be fitted with dampers for closing them more or less if found desirable.
The oil to be operated on is, ordinarily, supplied to the first compartment, B1, by
a pipe, K, and the vapors or gases evolved in that compartment pass by a pipe, L 1,
into the worm of a condenser, M. 1, the condensed products dropping into the second
boiler compartment, B 2. In like manner the vapors or gases evolved in the other.
compartments, B2, B3, pass by pipes, L2, L3, into the next compartments, B 3,
B4. There may be more or fewer than the four compartments shown if found
desirable. From the compartment, B4, or the last of the series, the vapors or gases
pass off by a pipe, N, to any suitable condenser or condensers.
The condensers, M, are supplied by a main and branch pipes, P, provided with
stopcocks, with cold water, which enters at their lower ends, the heated water
passing off from their upper ends by branch pipes and a main pipe, Q. As I believe
it will in some cases be desirable to cool the back end of the boiler, that is, the last
compartment, B4, I provide, there, a casing, R, with pipes, S, for supplying cold
water and leading off the heated water. And at the bottom of the back end of the
boiler I provide a pipe, T, for drawing off the unvolatilised residue from the oil.
In some cases the residue although liquid whilst hot, hardens on cooling into a
pitch of a good quality; and the operation of the apparatus may be varied and
regulated in a manner to obtain the residue or pitch in what may be considered to
be the best condition. The residue pipe, T, communicates with a receiver, U, fitted
with a cock, V, for drawing off a test sample, and also with a pipe for conveying
the residue to a more distant receptacle, the pipes, T, and W, being both fitted
with stopcocks.

page_text: When distilling mineral oil according to my improved system no steam unless
superheated is on any account to be let into or used in the still boiler as it would
prevent the efficient breaking up or decomposition of the oil. If the still is being
fed continuously, or indeed, in any case, great care must be taken to have the oil
"dry," that is, quite free from water. In each succeeding compartment of the still
more and more of the lighter oil is obtained; and the heat applied to the still
should be regulated so that what acts on the last compartment, B4, may be just
sufficient to volatilise the lighter oil and thus separate it from the heavier remaining
liquid. I apply a stricture valve, X, to the final delivery pipe or swan-neck, N,
which conveys the vaporised oil from the last compartment to the condensers, for
the purpose of by its means regulating the rate of delivery by reducing or
increasing the opening through the swan-neck.
In order to assist the regulating of the heat applied to the last compartment, B4,
I have a pyrometer, Y, applied to that compartment with its inner end immersed
in the liquid oil; and when the proper temperature for that compartment has
been determined by trials in the case of any particular kind of mineral oil, the
heat can thereafter be suitably regulated by aid of the pyrometer.
Pipes may be provided for supplying fresh or cold oil to any of the compartments
as well as to the first, such arrangement affording additional means for regulating
the effective temperatures within the apparatus. Suitable pressure gauges and
thermometers or pyrometers may be fitted to the apparatus wherever it may be
thought desirable. The actual internal pressure may be varied to a small extent
by means of the stricture valve, X, in the end outlet or swan-neck, N, and by
suitably regulating the action of the condensers or otherwise, it not being essential
to my process to restrict the internal pressure exactly to atmospheric pressure as
may exceed that pressure to a small extent, say not more than 10 pounds on
the square inch, or it may be less without injurious results.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved process of treating comparatively heavy mineral oils, in which,
by repeated distillations combined with intermediate condensations of the volatilised
portions, and carried on continuously and conjointly, the oil is subjected to
destructive or decomposing action and lighter products are obtained, substantially
in the nanner hereinbefore described.
2. The improved apparatus for the treatment of mineral oils, consisting of a still
or boiler divided into a horizontal series of compartments communicating with each
other at their bottoms and provided with pipes for leading volatilised matters from
each compartment through a condenser to the next compartment in order, the parts
being arranged, combined and operating in the manner and for the purposes
substantially as hereinbefore described.
Dated this Twelfth day of December 1890.
EDMUND HUNT,
Applicant's Agent.