Improvements in and Apparatus for Distilling, more especially intended for Distilling Tar.
Year: 1891

page_text: Date of Application, 16th Jan., 1891
Complete Specification Left, 16th Nov., 1891-Accepted, 19th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in and Apparatus for Distilling, more especially
intended for Distilling Tar.
I FREDERIC LENNARD of Ordnance Wharf Blackwall Lane East Greenwich
in the County of Kent Manufacturing Chemist do hereby declare the nature of this
invention to be as follows:-
:―
The object of my invention is to provide apparatus by means of which distillation
can be carried on economically and expeditiously and so as to obtain in a manner
readily under control the various products of distillation the heat of the vapours of
distillation being used to effect the preparatory heating of the matter to be distilled
which in their turn assist the condensation of the said vapours. My invention is
more especially intended for but is not restricted to the distillation of coal tar and
I will describe it as so applied. According to my invention the tar to be distilled
after passing through one or more of the condensers in which the tar vapours are
condensed and into boilers or heated vessels in which the ammoniacal liquors are
separated passes through coils or like extended passages subjected to heat which
may be applied in any suitable way for instance by the said coils or the like or
some of them being situated in a bath preferably a sand bath wherein the tar
becomes heated to the requisite degree and thence passes through a scrubber in
which it is subjected to the action of steam and wherein the pitch deposits whilst
the vapours pass therefrom into condensers in which the various products deposit
separately. The following is an arrangement of apparatus according to my
invention although I do not limit myself to the precise details which I shall
describe.
I provide a furnace with return flues and above it a sand bath in which are
situated coils which are in communication with other coils situated in a chamber
through which the products of combustion pass and which I call the superheater.
I provide also a scrubber consisting preferably of a vertical tower having series of
tubes so arranged that the tar will pass downwards therethrough in a somewhat
circuitous manner meeting a current of steam in its descent and at the bottom of
this tower the pitch deposits. I provide also condensers (say three) in which the
several products deposit separately these condensers preferably consisting of vertical
vessels provided with tubes and with outlets and inlets so arranged that the vapours
pass on one side of the said tubes whilst the cooling and condensing agent passes on
the other side of the said tubes. In the last condenser of the series the cooling
and condensing agent may be water whilst in the ethers it may be the tar which is
to be distilled. The tar enters say the last but one of the condensers and passes
around the tubes thereof and thence by a pipe to the boilers or vessels in which the
ammoniacal liquor is separated from the tar and retained the said tar passing thence
by a pipe to the next condenser and around the tubes thereof and therefrom by a
pipe to the coils in the superheater and thence through the coils in the sand bath
by which it is heated to the requisite degree. It then passes by a pipe into and
through the scrubber where it meets the current of steam and the pitch deposits at
the bottom thereof and the vapors passing off by a pipe to the first condenser
where the heaviest product (the anthracite oils) deposits the uncondensed vapours
passing by a pipe to the second condenser wherein the next product (creosote oils)
deposits the vapours which are still uncondensed passing into the last condenser
wherein the lightest product (naphtha) and the water deposit. The condensers
and scrubber are provided with outlets by which the deposited products run off.
The aforesaid coils are preferably flattened and to provide heating surface they
may have fins on them and to conduct heat to them there may be pipes or passages

page_text: of refractory material extending from the furnace to between the coils. The sand
may be covered with asbestos or the like to retain the heat.
By regulating the speed at which the tar is passed through the apparatus the
proper degree of heat for distilling is obtained irrespective of the temperature at
which the furnace and sand bath may be maintained.
Dated this 16th day of January 1891
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in and Apparatus for Distilling, more especially
intended for Distilling Tar.
I FREDERIC LENNARD of Ordnance Wharf Blackwall Lane East Greenwich in
the County of Kent Manufacturing 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 :-
The object of my invention is to provide means by which distillation can be
carried on economically and expeditiously, and so as to obtain in a manner readily
under control, the various products of distillation the heat of the
vapours of
distillation being used to effect the partial heating of the matter to be distilled
which assists the condensation of the said vapours. My invention is more especially
intended for (but is not restricted to) the distillation of coal tar to obtain its
various products of distillation and I will describe it as so applied as, from this
description, its application to the distillation of other matters to which it is
applicable will also be readily understood. According to my invention the tar to
be distilled passes or is forced from the store tank or like place into vessels in
which the ammoniacal liquor separates owing to the heated condition of the tar.
This heating of the tar is effected by forcing it (on its way to the said vessels)
through one or more of the condensers, so that the tar acts as the cooling medium
for condensing the tar vapours therein. The tar is then passed or forced from
these tanks or vessels through heated coils of pipes or like extended passages, the
heat being applied to the said coils or passages in any suitable way, for instance by
the said coils or the like, or some of them, being situated in an oven or bath which
may be a sand bath. The tar passing through these coils, or the like, thus becomes
heated to or above the point at which the vapourisable constituents thereof required
to be extracted would become vapourised if not confined therein, and passes into a
scrubber on admission to which its said vapourisable constituents vapourise, it being
therein subjected to the action of steam or other disassociating agent, the pitch
depositing in the scrubber whilst the vapours pass therefrom into condensers, in
which the various products deposit separately. The following is an arrangement
of apparatus according to my invention, although I do not limit myself to the
precise details.
I provide a furnace with return flues, preferably heated with liquid or gaseous
fuel, and above it an oven or bath (which may be a sand bath) in which are coils
communicating with other coils situated in a chamber through which the products
of combustion pass, and which I call the economiser. I provide also a scrubber
consisting preferably of a vertical tower, having series of tubular passages 80
arranged that the tar will pass downwards there-through in a somewhat circuitous
manner meeting a current of steam or other disassociating agent in, its descent,
which steam or like agent carries off the desired products from the tar, the pitch
which is thus formed depositing at the bottom of this tower. I provide also
condensers into which the vapourised products pass and in which the several
products deposit separately, these condensers preferably consisting of vertical vessels.
provided with tubes and with outlets and inlets so arranged, that the vapours. pass
inside the said tubes whilst the cooling and condensing agent passes on the outside

page_text: of the said tubes. In the first condenser of the series, the condensing agent may
be the tar from the ammoniacal liquor separators, whilst in the others it may be
the cold tar which is ultimately to be distilled. The tar to be distilled may be
pumped through, say the last of the condensers, and passes around the tubes thereof
and thence either direct by a pipe to the tanks or vessels in which the ammoniacal
liquor separates from the tar and is retained, or before passing to these tanks or
vessels, it may be passed through another of the condensers and around the tubes
thereof. The tar is forced from these tanks or vessels, by a pump into the first of
the condensers and thence through the coils in the economiser and thence through
the coils in the oven or bath by which the tar is heated to the degree requisite to
cause the aforesaid vapourisable constituents to vapourise when the tar issues
therefrom and passes into the scrubber where it meets a current or currents of
steam, or other disassociating agent by which the vapours are driven to the first
condenser wherein the heaviest products (the anthracine oils) deposit, whilst the
pitch deposits at the bottom of the said scrubber. The uncondensed vapours pass
from the first condenser into the second condenser wherein the next products
(creosote oils) deposit, the vapours which are still uncondensed passing into the last
of the condensers, wherein the lightest products (naphtha and light oils) are
condensed. The condensers and scrubber are provided with outlets by which the
deposited products run off.
Although I have mentioned three condensers any other number may be used in
[accordance with the number of "fractions or products of different densities
required.
The coils of the aforesaid economiser and oven or bath are preferably flattened,
and to provide extended heating surface they may have fins on them, and to
conduct hent to them there may be pipes or passages of refractory material
extending from the furnace or flues (or both) to between the convolutions of the
coils. Asbestos, slag-wool or the like and sand may be used as hereinafter
explained to retain the heat.
By regulating the speed at which the tar is passed through the apparatus, the
proper degree of heat for distilling is obtained irrespective of the temperature
above that required for distilling of tar, at which the furnace and the oven or bath
may be maintained.
And in order that my invention may be clearly understood, I will now proceed
more particularly to describe the same with reference to the accompanying
drawings, premising however that I do not restrict myself to the particular details
of the construction and arrangement of the parts described and illustrated, as
variations may be made therein without departing from the nature of my
invention.
Figure 1 of the drawings is a diagrammatic plan of an apparatus arranged
according to my invention.
Figure 2 is a longitudinal section.
Figure 3 a horizontal section and
Figure 4 a transverse section of the chamber containing coils through which the
tar is passed and which I call the economiser.
Figures 5, 6 and 7 are respectively a longitudinal section, a horizontal section
and a transverse section of the furnace and bath or oven containing coils through
which the tar passes and becomes finally heated as aforesaid before entering the
scrubber.
Figure 8 shows an elevation partly in section, the scrubber and condensers
through which the tar and vapours pass.
Figures 9 and 10 are respectively a vertical section, and a plan of two sections of
the scrubber drawn to a larger scale.
A Figure 1 is the tank containing the tar to be distilled from, which tank the
tar is drawn through a pipe C and forced through the pipe D by the pump B, into
one of the condensers for example the condenser E through which it passes outside

page_text: and in contact with the surfaces of the tubes E' (Figure 8) therein. From the
condenser E the tar may if desired be conducted direct to tanks or vessels such
as G in which the ammoniacal liquor separates from the tar two or more being
used in order that the ammoniacal liquor may separate in one or more of them
whilst the tar is being taken from the other or others of them in which the
ammoniacal liquor has already separated from the tar, branch pipes and cocks being
provided as shewn to enable each vessel to be put in communication with the
pumps tanks and condensers as required. The tar may however (as shewn in the
drawings) be conducted by the pipe H from the condenser E into another of
the condensers E' and thence by the pipe H' to the vessels G. The tar is drawn
from the vessels G through the pipes i by a pump I and forced by the said pump
through a pipe K into the condenser E' and thence through a pipe K2 into a coil L
(see Figures 2. 3 and 4) in the economiser M whence it passes through m' into
another coil L (or a continuation of the coil L) contained in an oven or bath N
(see Figures 5. 6 and 7). In order to keep the said coils evenly supplied and
properly filled with tar I prefer to provide the pipe K with a stand-pipe k into
which any vapours formed in the condenser E' may pass, and with an overflow
pipe leading back to the vessels G through which pipe any surplus tar passes
back to the said vessels or one of them. The tar in passing through the coils L, L'
becomes highly heated to the point at which constituents required to be obtained
will vapourise when the tar emerges from the coil into the scrubber. The tar so
heated is conducted by the pipe O and rose nozzle P (Figure 8) into the upper
part of the scrubber Q wherein the pitch formed and separated from the other
constituents passes to the bottom of the scrubber and out therefrom by the pipe Q
into the tank or reservoir R. The vapours from the tar are driven (by means of
steam or other disassociating agent admitted at t to the lower part of the scrubber)
through a finely perforated plate and conducted by, a pipe S into the upper end
of the condenser E' and into the tubes E thereof and therein part of the vapours
is condensed by the tar or condensing agent circulating through the condenser over
the exterior surfaces of the said tubes so that the heaviest products (namely the
anthracene oils) deposit in the bottom of this condenser and pass therefrom by the
tube T into and through a coil of pipe contained in a water tank U and therefrom
by the pipe Y into a storage vessel or reservoir W. The uncondensed vapours
pass from the condenser E by the pipe X into the tubes E' in the next
condenser E' wherein the next lighter products, namely, the creosote oils, are
condensed by the circulation of the tar or cooling agent over the outer surfaces of
the said tubes E the condensed products passing from the condenser El by the
pipe T through a coil in a water tank UI and therefrom by the pipe Y' into a
storage reservoir W'.
The vapours which are still uncondensed pass by the pipe X' into the upper part
of the condenser E and in passing through the tubes E' therein the lighter products
(namely naphtha and other light oils) become condensed and deposit in the bottom
of the condenser E from whence they are conducted by a pipe T* into a coil of
pipe in a cold water tank Us and thence by the pipe Y into the storage tank or
reservoir W
'
Having given a general description of the process for distilling tar according to
my invention I will now describe what I consider the best construction of the
apparatus for carrying out the said process.
The separating vessel or vessels G into which the tar is conducted after circulating
round the tubes in the condensers may resemble ordinary boilers. The economiser
through which the tar passes after leaving the settling tanks or vessels G consists
of a closed chamber M containing a coil L of tubes, preferably of an oval or
flattened form in cross section as shewn in Figure 4 and also preferably provided
with fins gills or flanges c for increasing the heating surface. This coil L is
supported on brick piers d above the bottom of the chamber M so as to permit
of the circulation beneath the coil of the products of combustion by which it and

page_text: the chamber M are heated. The chamber M is divided longitudinally into
compartments by transverse brick partitions e through which the coil passes, - these
partitions having therein perforations or holes below the coil.
The heated products of combustion for heating the coil L may be supplied
from any suitable source but I prefer to utilize for this purpose the otherwise waste
products of combustion passing from the furnaces employed for heating the bath
or oven hereinafter described.
The heated products of combustion from these furnaces enter the economiser
by the passage
and pass upwards between the convolutions of the coil L and over
the first brick pier d thence down through the convolutions of the coil behind this
pier and through the perforations in the first partition e, they then pass upwards
through the convolutions of the coil on the opposite side of this partition and over
the next pier d and then again downward between the convolutions of the coil and
through the perforations in the next partition and so on to the opposite end of
the chamber they finally escaping by the passage / leading to the chimney. The
tar passing through the said coil becomes further heated and passes from this
coil into a similar coil L' arranged in the bath or oven shewn in Figures 5. 6.
and 7, Figure 5 being a longitudinal section, Figure 6 a horizontal section and
Figure 7 a transverse section of the said bath or oven. In order to retain the
heat the coil L' may be covered by fire tiles and above them there may be a
covering of slag-wool or equivalent material 12 and over this a bed of sand or
the like. Slagwool or other non-conducting material may be placed in the walls of
both the economiser and the oven or bath to still further retain the heat, for
instance as shewn at in Figure 7. Beneath the coil L furnaces m. in are
arranged and preferably heated by liquid or gaseous fuel but I do not restrict
myself to the use of such fuel. The products of combustion pass along the flue n
to the back end and then return to the front by the flues o thence passing back
again to the back end by the central flue p and out therefrom into the economiser
by the passage g as hereinbefore described.
Projecting from the crowns of the furnaces m and flues n o p are hollow
chambers q which extend upwards between the convolutions of the coil L'. The
heated products of combustion enter these hollow chambers whereby they become.
highly heated and thereby in addition to the gills c on the coil provide a considerably
extended heating surface for heating the bath or oven. The coil L is thus highly
heated and maintained at the required temperature by the heat from the furnaces m
so that the tar passing through the coil becomes heated to such a degree that the
constituents which it is desired to obtain are vapourised as soon as it is admitted
to the scrubber. The scrubber preferably consists of a tower composed of a
number of castings r sèe Figures 8. 9. and 10 having tubular passages therein so
arranged one above another that the tubular passages in each casting do not
coincide with the tubular passages in the adjacent casting or castings but so that
those in one overlap or break joint with those in that or those castings next to it
thereby providing a number of zig-zag passages through the scrubber over the
surfaces of which the tar descends. Steam is admitted to the lower end of the
scrubber by the pipe t the vapours from the tar being driven by this steam through
the pipe S into the upper end of the condenser E thence into the condensers E¹
and E in succession in which condensers the various constituents are deposited as
hereinbefore described.
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. In distilling tar or the like, heating it in coils or passages to a degree which
will cause its required constituents to vapourize when relieved from confinement in
the said coils or passages and causing the said tar or the like so heated to enter
and its said constituents to vapourise in a scrubber into which steam or other
disassociating agent is admitted all substantially as herein before explained.

page_text: 2. In distilling apparatus the combination of a settling tank or vessel or settling
tanks or vessels into which the matter to be distilled is conducted before being
heated to the distilling point, an economiser containing a coil of pipes through
which the matter is caused to travel and become further heated after leaving the
depositing tank or vessel and a bath or oven or equivalent heating device containing
a coil of pipes through which the matter from the economiser passes and in which
it is finally heated and a vessel in which vaporisation takes place all substantially
as herein before described.
3. In distilling apparatus a bath or oven or equivalent device containing a coil
of oval or flattened pipes having gills or extended heating surfaces through which
coil the matter to be distilled is caused to travel and become heated as described
and means for heating the bath or oven consisting of a furnace or furnaces and
flues arranged beneath the bath or oven and provided with hollow chambers or
passages for admitting heated products from the furnace or furnaces and extending
from the crown of the furnace or flues (or both) into the bath or oven the whole
being arranged substantially as and for the purpose herein before described with
reference to Figures 5. 6 and 7 of the accompanying drawings.
4. In distilling apparatus a column consisting of a series of casting containing
tubular passages arranged out of line with each other so as to form circuitous or
zig zag passages down which the tar flows and up through which steam or other
disassociating agent is passed to force the vapours from the column into condensers
substantially as hereinbefore described.
5. The combination of parts constituting apparatus for distilling tar or other
matters and for separating the different constituents and conducting them into
separate reservoirs or store vessels substantially as herein before described and
illustrated in the accompanying drawings.
6. The process of distilling tar or the like consisting in subjecting it to the series
of processes in apparatus arranged substantially as herein before described.
Dated this 16th day of November 1891.
J. H. JOHNSON & Co.,
Agents.