Improvements in the Manufacture of Illuminating Gas and in Apparatus Employed therein.
Year: 1888

page_text: Date of Application, 11th Feb., 1888
Complete Specification Left, 10th Nov., 1888
Complete Speci cation Accepted, 11th Mar., 1889
Improvements in the Manufacture of Illuminating Gas and in
Apparatus Employed therein.
I JOHN HENRY RICHARDSON DINSMORE, Engineer to The Dinsmore Gas Company
Limited, Liverpool, in the County of Lancaster do hereby declare the nature of the
said invention to be as follows:-
This Invention relates to the manufacture of illuminating gas from coal in closed
vessels, or retorts, but it relates more particularly to those processes of manufacturing
illuminating gas by which it has been proposed to render permanent, practically all
the heavy, or tarry vapours, or liquors, as well as the light products given off from coal
by distillation, and to so make them useful for the production of light and heat.
My present Invention has for its object amongst other things, (a) to convert the tar,
or tarry liquors, or tarry vapours given off from coal in distillation into permanent
gas, (b) to effect this object and those above specified, and (c) to carry out these and
other objects incident to the process by apparatus in which the ordinary retorts of gas
works are rendered available for making gas according to my Invention.
I will firstly describe the mode, or method by which I convert the tarry products
resulting from the distillation of coal in retorts into permanent gas. It is found in the
manufacture of gas whether produced in the ordinary way, or in the manner herein-
after described, or referred to, that a certain quantity of tar, or tarry products are
obtained from the gas when cooled. It is these matters or products which I convert
into permanent gas, and the essential feature of this portion of my Invention consists in
introducing such tar, or tarry products into heated ducts, or vessels in the presence of
gas which is being, or has been produced from coal. This method may be carried out
in various ways and in various forms of apparatus, but I prefer to carry it out by
collecting the tar and tarry liquids in a "dry" main, through which the gas passes on
its way from the retorts, and conveying them back to the retorts, or heated ducts,
hereinafter described, whereby they would be converted into gas in the presence of the
gas passing off from the coal and through the retort, or ducts. This may be con-
veniently effected by providing pipes with suitable traps to prevent the gas passing

page_text: through them, communicating between the gas main and the ducts, or the
"hydraulic main or "tar trap" hereinafter described. In this way of carrying out
this part of my Invention the tar, or tarry liquor would be conveyed back to the heated
retort, or ducts at the time most conducive to the best efficiency, that is, while the
hydrogen of the coal gas is present and in such a condition that the gases resulting
from the vapourized tar combine with it, and form permanent gas.
Under head (c) my Invention consists in the construction and arrangement of gas
making apparatus of the type above specified, by which the retorts at present in use in
gas works can be used.
In setting forth an example of the application of this head of my Invention, I will
take aud describe it as applied to a bench of single retorts set in the ordinary way.
Then in such an instance above the nest of retorts and subjected to the heat of the
furnace gases I dispose a number of sets of pipes through which the gas after loaving
the retort is passed. The ordinary existing form of retort mouth and lower length
of the ascension pipe may be used when required, or suitable; or the retorts
may be provided with special mouths and ducts, connecting them with the above
specified heated ducts, or pipes. The gas made in the retorts is led from the
mouths of the retorts. to the heated ducts and passed through them, and the
greater portion of the gas is thereby rendered permanent.
The heated ducts may be either plain pipes, or they may be provided with cooled
passages, or surfaces, by which the bulk of the non-permanent and tarry vapours
would he arrested and caused to flow back into them and ultimately converted into
permanent gas. It is preferred that each retort should be provided with its own
duct, or set of ducts.
It will be seen from the above description that to use the existing retorts of a gas
works in apparatus constructed according to this Invention, it is only necessary to
provide the sets of heated ducts, with or without cooled surfaces, or passages
and place them above the retorts as described, the gas made in the retorts
being passed through the heated ducts. In some instances it will be necessary to add
to the height of the retort bench walls and to raise the roof, but it is evident that the
nature and degree of alteration, or addition required will necessarily depend upon the
condition under which the Invention is to be applied.
Although this object of my Invention is, as above stated, to use existing retorts of
Gas Works, in the manner I have already described, yet the arrangement and con-
struction of Gas making apparatus herein described is equally applicable to cases
where it is desired to build new retorts and retort benches.
The heated ducts may be arranged and disposed in any suitable and convenient way,
and one, or more pipes, through which the gas passes, may be used in connection with
each retort.
One convenient arrangement of heated ducts provided with cooled surfaces, consists
of two ducts disposed horizontally, or at an inclination, and having at their rear ends
upright parts which pass through the roof of the bench. At this point they are
provided with a cooling jacket and a chamber in which the said ends of the pipes open.
In this chamber tar or tar and water is maintained and the chamber is so constructed
that the gas has to pass through a small depth of liquor in its way from the exit of one
pipe to the entrance of the other. This chamber forms a kind of sealed "hydraulic
main," or "tar trap," one portion being open to the atmosphere, and into this trap the
tarry liquors from the gas main may be led, as above described. They will thereby
flow over the lip of the first upright duct--which is the lower of the two-and down it
and so convert it into gas and go along with the rest. At the exit of the second pipe
I may provide a second cooling jacket or surface also vertically placed upon a second
upright portion of the pipe. Suitable doors are provided at all points where required
for gaining access to the interior of the pipes for cleaning, or scraping.
By the latter construction of ducts the coal is distilled in a retort and passed through
a heated duct and then is passed through a cooled passage. After this it is again
passed through a heated duct and then finally through a cooled passage. By this
means the gas is first subjected to heat after leaving the retort by which a great portion.

page_text: of the gases in a non permanent state are made permanent. It is then subjected to a
cooling influence and thereby the greater portion of the condensable tarry vapours, or
gases are arrested by condensation, the tar resulting therefrom falling into the beated
ducts is reconverted into gas; and finally the gases, or vapours still existing in the
gas are again subjected to a cooling influence and a portion of the tarry vapours are
thereby condensed and fall into the heated duct where they are converted into gas.
I would have it understood that this Invention is not confined to any of the particular
arrangements, combinations or construction of parts herein defined, as these may be
varied according to the requirements of the particular application of the Invention
without departing from the spirit, or scope of it.

page_text: Improvements in the Manufacture of Illuminating Gas and in
Apparatus Employed therein.
I JOHN HENRY RICHARDSON DINSMORE, Engineer, of The Dinsmore Gas Company
Limited, Liverpool, in the County of Lancaster, do hereby declare the nature of
my said invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This Invention relates to the manufacture of illiminating gas from coal in closed
vessels or retorts, but it relates more particularly to those processes of manufacturing
illuminating gas by which it has been proposed to render permanent, practically all
the heavy or tarry vapours or liquors, as well as the light products, given off from
coal by distillation, and to so make them useful for the production of light and heat.
My present Invention has for its object, amongst other things, (a) to convert the
tar or tarry liquors, or tarry vapours, given off from coal in distillation, into permanent
gas; (b) to effect this object and those above specified by certain modes or
methods and apparatus, and (c) to carry out these and other objects incident to the
process by apparatus in which the ordinary retorts of gas works are rendered
available for making gas according to my Invention.
I will firstly describe the mode or method by which I convort the tarry products,
resulting from the distillation of coal in retorts, into permanent gas. It is found in
the manufacture of gas, whether produced in the ordinary way, or in the manner
hereinafter described or referred to, that a certain quantity of tar or tarry products
are obtained from the gas when cooled. It is these matters or products which I con-
vert into permanent gas; and the essential feature of this portion of my Invention
consists in introducing such tar or tarry products into heated chambers, ducts, or
vessels, in the presence of gas which is being, or has been produced from coal used in
the retorts. The method may be carried out in various ways and in various forms of
apparatus, for instance I may carry it out by collecting the tar and tarry liquids in a
tar main through which the gas may also pass on its way from the retorts, and con-
veying them back to the retorts, or heated ducts, hereinafter described, whereby they
would be converted into gas in the presence of the gas passing off from the coal and
passing through the chamber, retort, or ducts. In carrying out this part of my
Invention, the tar or tarry liquor would be conveyed to the heated chamber, or ducts
at the time most conducive to the best efficiency, that is, while the hydrogen of the
coal gas is present and in such a condition, that the gases resulting from the vapourized
tar combine with it and form permanent gas.
Under head (c) my Invention consists in the construction and arrangement of gas
making apparatus of the type above specified, by which the retorts at present in use in
gas works can be used.
In setting forth an example of the application of this head of my Invention, I will
describe it as applied to a bench of single retorts set in the ordinary way. Then, in
such an instance, above the nest of retorts and subjected to the heat of the furnace

page_text: gases, I dispose one or a number of ducts or pipes through which the gas, after leaving
the retort, is passed. The ordinary existing form of retort mouth and lower length of
the ascension pipe may be used when required or suitable; or the retorts may be
provided with special mouths and ducts, connecting them with the above specified
heated ducis, or pipes. The gas made in the retorts is led from the mouths of the
retorts to the heated ducts and passed through them, and the greater portion of the
gas is thereby rendered permanent.
The heated ducts may be provided with cooled passages or surfaces by which
more or less of the non-permanent and tarry vapours would be arrested and caused
to flow back into them aud be ultimately converted into permanent gas.
retort or set of retorts is provided with its own duct or set of ducts.
Each
It will be seen from the above description that to use the existing retorts of a
gas works in apparatus constructed according to this Invention, it is only necessary
to provide the duct or ducts, or sets of heated ducts, with cooled surfaces or
passages, and place them above the retorts as described, the gas made in the
retorts being passed through the heated ducts. In some instances it will be necessary
to add to the height of the retort bench walls and to raise the roof, but it is evident
that the nature and degree of alteration or addition required will necessarily. depend
upon the condition under which the Invention is to be applied.
Although this object of my Invention is, as above stated, to use existing retorts of
Gas Works, in the manner I have already described, yet the arrangement and con-
struction of gas making apparatus herein described is equally applicable to cases where
it is desired to use new retorts and build new retort benches.
The heated ducts may be arranged and disposed in any suitable and convenient
way, and one, or more pipes through which the gas passes may be used in connection
with each retort or set of retorts.
In the case where each retort is provided with a separate heated duct a convenient
arrangement of heated ducts and cooled surfaces consists of two ducts disposed
horizontally, or at an inclination, and having at their rear ends upright parts which
pass through the roof of the bench. At this point they are provided with a cooling
passage and a chamber in which the said ends of the pipes open. In this chamber
tar or tar and ammoniacal liquor is collected, and the chamber is so constructed
that the gas has to pas- through a small depth of the liquor on its way from the exit
of one pipe to the entrance of the other. This chamber forms a kind of
sealed "Hydraulic main," or "tar trap,"-one portion being open to the atmo-
sphere, and into this trap or pipe connected therewith the tarry liquors froin the gas
main and condensers may be led. The tar so collected will flow over the lip of the
first upright duct which is the lower of the two-and fall down it into the duct, and
will be so converted into gas and go along with the rest. At the exit of the second
pipe I may provide a second cooling passage also vertically placed upon a second
upright portion of the pipes. Suitable doors are provided at all points where
required for gaining access to the interior of the pipes for cleaning, scraping, or other
purpose.
By this latter construction of ducts the coal is distilled in the retort and passed
through a heated duct and then is passed through a cooled passage. After this it
is again passed through a heated duct and then finally through a cooled passage.
By this means the gas is first subjected to heat after leaving the retort by which a
portion of the gases in a non-permanent state are made permanent. It is then
subjected to the cooling influence of the passages and thereby more or less of the
condensable tarry vapours or gases are arrested by condensation, the tar resulting
therefrom, as well as that introduced into the chambers or passages, falling into
the heated ducts is reconverted into a vapourous or gaseous state; and finally the
gases or vapours still existing in the gas are again subjected to a cooling influence
and a portion of the tarry vapours are thereby condensed and fall into the heated
duct where they are converted into gas.
The above description sets forth generally the nature, object, and purposes of my
Invention, but to make the same more clear 1 will now proceed to describe it with

page_text: The drawings together with the following description of them set forth examples of
apparatus or plant in and by which the manufacture of gas according to this Invention
may be conveniently and successfully conducted, and at the same time they illustrate
apparatus specially designed to apply the method of the manufacture of gas, the mode
of operation of which has been above generally described.
DESCRIPTION OF THE DRAWINGS,
Figure 1 shows in sectional elevation, an apparatus embodying improvements
according to my Invention.
Figure 2 is an end view, partly in section, of the apparatus shown in Figure 1.
Figure 3 is a sectional elevation of a modified form of construction of the apparatus
illustrated in Figures 1 and 2; and Figure 4 is an end view partly in section of
same.
.
Figure 5 shows in sectional elevation another modified form of the apparatus
illustrated in Figures 1 and 2; and Figure 6 is an end view partly in section of
same.
Figures 7 and 8 show respectively, in sectional elevation and part sectional end
view, a further modified form of the apparatus shown in Figures 1 and 2.
Figures 9 and 10 are, respectively, sectional elevation and plan of a modified form
and arrangement of the parts connected with the heated duct, and illustrated in
Figures 7 and 8.
Figures 11 and 12 are details of the hydraulic main or tar tap, shown in Figure 1
and Figure 8, respectively.
Throughout the views of the drawings like letters and figures are used to denote
like or corresponding parts of the apparatus.
With reference in the first instance to Figures 1 and 2 of the Drawings, A
designates the bench of retorts set closely together in the ordinary way, B B are the
heated ducts, each retort A being provided with a double duct B, B; Care chambers
which are constructed in the form of a trough, and D, E are cooled passages. a are
the retort mouths, and a³ are the ascension pipes communicating between the retorts A
and ducts B. 6 6 are passages or pipes leading from the ducts Band the passages DD
and E, respectively.
In this example if A represents a set of existing retorts, then all that is necessary
to do to render these existing retorts applicable for use in carrying out this Invention,
is to introduce the heated ducts B and apply the chamber or seal trough, and
cooled passages; the other details or parts being either retained or others used in
their place as may be required or deemed expedient.
The chambers C consist of a horizontally arranged trough separated into a number
of sub-chambers by partitions ; each chamber is provided with passages D, a
curtain d and a cooling jacket d'at one side, and the bottom thereof. The water jacket d
is formed between the walls d' and d' of the chamber. The sealing in the chambers C,
by which gas is prevented from returning to the retorts when their doors are opened,
is effected by the curtains a², the lower edge of which dip into the tar which lies in
the trough between the two pipes forming the passages D. D. The curtain d is
provided to separate the chambers C into two parts, one being the part through
which the gases from one of the cooled passages D pass from one to the other of
the passages D; and the other being the part to which the tar return pipe c³, and a
ammoniacal liquor escape pipe c¹ is connected, and into which the tar returned from
the gas main and condensers is or may be introduced. The upper part of this portion
is open to the atmosphere as shown, and the lighter liquors which find their way into
it are taken away from it by the escape pipe c'. When the liquid in this outer
part rises to a certain height above the lips of the passages D, the tar, which will lie
at the bottom, will be forced under the edge of the curtain d and up into the inner
portion of the trough C, and so on up to the level of the lip of the passages D.
When it rises to slightly above this level it falls over the lip of the passage D and

page_text: down the same.
In falling down the pipes D, and before entering the ducts B, the
tar will have to flow over the toe d, at which point the passages are contracted.
From this toe the tar drops directly on to the red hot surfaces of the horizontal
portions of the ducts B. The lighter liquor from the outer portions of the chamber D
is, as above described, carried off by a pipe c¹ which may be trapped and the level
of which with respect to the chamber is determined. The exit passage E is
maintained in a cool condition by the jackets contained between the walls and,
through which water or other suitable cooling fluid is passed. This passage is also
provided with a toe d³, by which, matters condensed within it, in falling towards
the ducts B, are caused to fall directly from said toe onto the red hot portion on
the bottom of the duct B. All cooling jackets are provided with suitable water
circulating inlet and outlet pipes i.
In lieu of introducing the tar into the ducts B, in the manner just described, it
may be returned from the mains, condensers, or other parts of the apparatus and
introduced by pipes c³, shown in dotted lines, passed into the passages D, and provided
with a delivery orifice arranged as shown, in such a manner, that such tar will fall
directly from the orifice onto the bottom of the ducts which will be rod hot.
In all cases the supply of tar to the duct B must be a regulated one whether
such supply to the duct be direct or indirect and little or no more tar than is
capable of being gasified by the duct must be supplied to it; that is to say, the
quantity of tar must be regulated in such a manner that the temperature
at the surface or surfaces of the duct B, in or onto which the tar falls,
will not be thereby reduced below an efficient gasifying point; such a temperature
I have found to be that of or denoted by a bright cherry red colour. The supply
to the pipes will therefore be provided with any well known regulating means or
device.
As to the proportion of ducts or retorts, and the quantity of tar produced from
the coal distilled in such retorts, that may be introduced into the ducts, it may be
said, that, as the size and amount of heated duct surface nsed and caused to act on
the tar, in a bench of apparatus, is to the size and number of distillatory retorts or
the quantity and quality of the coal distilled in said retorts, and the quantity of tar
produced from such coal, so will be the quantity of tar capable of being vapourized
or gasified by the said duct surface, to the quantity produced.
The operation and process and effects of manufacturing gas in the apparatus above
set forth are as follows:-
the
The coal is placed in the retorts A and distilled by heat in the ordinary way, and
gas
evolved from the coal is passed in to the lower hot duct B of each retort,
by its ascension pipe a', and on through the upright pipe b, the cooled passage D,
into its trough or chamber C. In this passage and chamber it deposits a part of
its tar and condensable matters, such as ammoniacal vapours; it then passes under the
sealing curtain a³ and down through the second artificially cooled passage D, into
the upper of the heated ducts B. It leaves this duct by the pipe 6 and the cooled
passage E, wherein a further quantity of tar and other condensable matter is arrested
or condensed. In the condition the gas enters the lower of the ducts B, a portion
of it is not permanent, but in passing through the duct, the whole is subjected to
the heat thereof, and the greater part of the non-permanent portion is thereby
rendered permanent. The tar deposited from the gas in the chambers C, and the tar
and other liquors coudensed in the passage D, together with the tar introduced by
the pipe c, all fall down to the bottom of the ducts B, where they are gasified by the
heat of the duct, and in the presence of the gas passing through such duct. In the
same way the matters condensed in the cooled passage E fall, as above described,
into the duct B and are gasified in the presence of the coal gas passing through
such duct.
After the gas leaves the distilling apparatus illustrated, it may be conducted through
a considerable length of inclined pipe, as is very commonly practised, before the
delivery of the condensing and washing apparatus, and in traversing the pipe a
certain quantity of tar will be removed from the gas. This tar, as above stated,

page_text: together with the tar recovered by the condensers, I bring back to the distilling
apparatus by gravity or otherwise by pipes c³ as described, and I cause it to be
introduced into the hot ducts B and to be there gasified in the presence of freshly
distilled gas coming from the retorts A so converting it into permanent illuminating
gas.
In the modified arrangement shown in Figures 3 and 4 I provide in
connection with each retort A, a single heated duct B, instead of a double one,
and the gas is passed, prior to entering the heated ducts, through the first cooled
passage D. The gas in passing to the cooled passage D, from the retort A, first enters
the upper part of the cooled passage D, which constitutes a chamber C, and then
passes through the cooled passage D into the duct B, finally leaving the apparatus by
a cooled passage placed on the end of the duct outside the bench as shown in
Figures 5 and 6, namely, the passage E. The passage D is mounted on the upright
portions b, and is provided with a toe d³. In this case the tar deposited in the
chamber C is conveyed to the tar well in the usual way and is returned to the apparatus
from the condensers, and gas mains, and introduced into the ducts B in regulated
quantities through the walls of the passages D, by pipes c³. The parts in the process
played by the cooled passage D and that at the end of the duct, and the toes d', are
the same as those described with reference to Figures 1 and 2. To prevent the gas
from the main escaping from the retort when the retort door is opened, 1 provide a
cap valve k over the pipe of the chamber C; the valve is operated by a lever k¹,
and when closed fits over the said pipe, whilst in its open position it is raised out of
the liquor in the chamber, as shown. It will be evident that in lieu of this cap valve
any other suitable known kind of valve can be used and applied at any convenient
point of the pipes or passages connected with the ducts.
The modified arrangement of apparatus shown in Figures 5 and 6, illustrate a bench
of gas-making retorts and apparatus wherein one heated duct B is employed in
conjunction with two retorts A; that is to say, the products of distillation of the
charges of coal of two retorts are together passed through one duct, and subjected
to the action of such duct, and the cooled passages connected therewith.
or it is
In this example the heated ducts B are set above the retorts A, the latter being set
in a bench in the usual way. The seal chamber C is in the form of a trough, and is
either common to all the retorts and ascension pipes a' and dip pipes a
separated into two by a partition. It will be seen that the duct, and its cooled
passages D and E are arranged similarly to those illustrated in Figures 3 and 4,
except that the rear end of the duct B is prolonged and carried outside the end wall of
the retort bench, and the upright portion b¹ of the duct is dispensed with, the cooling
passage E being secured directly to the mouth piece at the end of the duct B. Beneath
the passage D in this arrangement I provide an inclined gutter l, by which the
liquid matters falling upon it, flow down over its hot surface, and then onto the red
hot surface of the duct. It may be here remarked that like or equivalent gutters may
be disposed beneath the passages E so as to cause the liquids falling upon thom to
gravitate down them, thereby in both cases causing a larger heated area to be used
and to act upon a given quantity of tar to gasify it, than would be availed of were the
the surface arca horizontal. This arrangement of inclined surfaces, also in effect,
constitutes a means by which the tar is distributed over the hot surfaces of or in the
duct. The same end may be obtained by providing the duct B with an inclined
bottom, in such a manner, that the liquid matters falling thereon would gravitate
towards each other, that is, towards the centre of the duct. The inclined gutters, not
being fixed devices, may be readily removed from the ducts for cleaning, renewal, or
other purposes.
The evaporative or gasifying power of a duct of given size and conditions, that is,
the amount of tar capable of being gasified by a duct having the provisions or con-
struction just described by which the tar is distributed, would be greater than it would
otherwise be. The seal chamber C and cooled passages D consist of a horizontally
arranged trough, and passages descending from such trough, at right angles to it, the
whole being supported on the upper end of the vertical entrances 6 of the ducts B.

page_text: The liquid deposited in the trough C. which will chiefly consist of tar and ammoniacal
liquor, is conducted away by the pipe c¹ to the ordinary tar well as hereinafter
described.
The dip pipes are immersed in the liquor in the trough C to a depth just sufficient
to seal them under working conditions. The cooling passage D is composed of
walls d, d, leaving an annular space between then, in which space the cooling
fluid is circulated. The bottom of the trough C is also of double formation as shown
forming a space for cooling fluid; this space and the space d' of the cooling passage D
communicate freely with each other, and the cooling fluid used is common to both.
The chief object of cooling the trough C is to keep the tar in it in a fluid state. It
will be obvious, if the cooling fluid be water, its temperature will be considerably
greater than that of the atmosphere, nevertheless it will be of sufficiently low
temperature for the purpose of keeping cool the trough C and passage D; the result
of which is that the tar in the trough C is kept in a freely liquid state, and the passage
cool enough to prevent the deposition of carbon or pitch therein and the choking up
of them or other pipes connected with the apparatus. These latter remarks refer to
all passages or parts which are kept in, or which it is necessary or desirable to maintain,
in a comparatively cool condition.
It will be seen that by sealing the dip pipes a² from the retorts as described, and
providing an outlet d' com:non to two of the retorts A, no through communication
between the trough or duct and the retorts A exists, and that when one retort is
opened for any purpose, the escape of gas from the trough or duct, back to the retort
or retorts, is prevented, and the process of distillation of the other or others is not
impeded.
In the apparatus I provide an arrangement by which the gas can be diverted from
its normal course or passage through the duct belonging to two retorts through
the duct of the other two retorts. The condition that renders this necessary is
that from time to timo access must be had to the interior of the ducts B, in order,
amongst other things, to clean and scrape them or to examine, remove, or renew
the gutters above specified. This necessitates the removal or opening of the
doors of the ducts; which obviously cannot be done whilst either of the retorts
belonging to a duct is in operation, without a large loss of gas taking place. To
avoid this the pipes d' which connect the chamber with the passages D. are each
provided with a cap valve k-which under working conditions is lifted off the pipe d';
and the pipes F leading from the cooled passages E to the foul main F¹ are provided
with valves m which under ordinary conditions are open. If however one of the
valves m be closed and.the corresponding cap valve k closed. then all the gas entering
the chamber from the retorts is caused, for the time being pass through the other
duct B. In lieu of diverting the gas as just described, it may be effected by being
passed through the pipe F2 shown in dotted lines, to the foul main F. This pipe F¹
is provided with a controlling valve n by which the gas is either by-passed or caused
to travel its normal course. The cooling surface of the pissage commences
practically from the entrance of such passage from the mouth of the duct B.
In Figures 3. 4. 5 and 6 the ducts B are provided with flat bottoms, this form in
some degree causes the tar to be distributed if allowed to fall thereon and therefore is
a good form, especially where no internal gutters or other distributing device or
means is provided.
In describing the operation and process of manufacturing gas in and by the appa-
ratus above set forth-which are as follows-I will take, for the sake of simplicity, a
set of two retorts and their common duct --The coal is placed in the retorts A and
distilled by boat in the ordinary way, and the gas evolved from the coal is passed into
the trough or chamber C; hore it deposits a part of its condensable matters, such as
tar and ainmoniacal vapours, it then passes through the artificially cooled passage D,
wherein some quantities of the tar and other condensable matters in it are arrested.
After leaving this passage, the bulk then passes on to the heated duct B. At the
termination of the duct, the gas comes under the cooling influence of the artificially
cooled passage E, and a portion of the tarry or non-permanent vapours still existing
B

page_text: in the gas are arrested and condensed. The matters condensed in this passage E, as
well as the heavier portion of those condensed in the passage D, fall back into the
duct B, and in the presence of freshly distilled gas from the retorts A are converted
into permanent illuminating gas. The tar, ammoniacal and other lighter liquors
condensed in the chamber or trough C, are, in this arrangement, drawn off by the
pipe c', and are led by this pipe to the ordinary tar well as already stated.
The tar condensed in the chamber is conducted to the tar well, as well as that
condensed in the foul main and condensers, and it is brought back from the well, by
gravity or mechanical force, to a vessel (not shown in the drawings) placed above the
level of the apparatus, and from this vessel the tar to be used and gasified in the
ducts is drawn off, as follows:-
From the said tar vessel I lead a pipe ce to a tar main placed near the chamber C,
and on this tar main is provided, for each duct, a branch pipe c', each of which is
provided with a cock c. From these pipes the tar is delivered in a regulated
quantity such regulation being effected by the cock into the separate and
independent trapped pipe, tho delivery orifice of which lies within the passage D.
The delivery orifice of the pipo c3 being arranged in the passage D the tar is caused
to fall from them direct onto the highly heated surface at the bottom of the duct B,
or onto an equally hot surface of the gutter / placed therein.
d¹
The pipe by which the gas passes from the chamber C into the passage D, and
by which the liquor in the chamber is prevented from entering the passage D-
and said passage D, are purposely made smaller than the entrance of the duct B, in
order that the liquids, falling from the toe d of the passage D, shall not, in falling,
touch any portion of the hot duct which is not red hot and of sufficient temperature
to gasify it.
I have found that if tar be supplied to a heated chamber, pipe or duct in the
manner I have herein described, that is, onto the red hot surfaces thereof, and in the
presence of gas, freshly distilled, from the retorts, and if the tar be distributed over
sufficient area of hot surface, and the volume of supply regulated, nearly the whole of
the tar may be converted into permanent illuminating gas; but if, on the other hand,
the tar be allowed to flow to a hot surface, over a service of gradually increasing heat,
to one that is red hot, or to flow or fall onto one not at a red heat, a greater or less
proportion of the tar will not be so distilled or gasified, a portion of it being deposited
as carbon and pitch; and for that reason, in all forms of apparatus, and modes of
operating them, according to my Invention, I prefer to arrange the apparatus in such
a manner, and cause the introduction of the tar to take place in such a manner,
that it is delivered or falls onto the red hot surface directly as described. At the
same time the results attained by the use of my Invention may, to a somewhat
less degree, be obtained when the tar is introduced in any other modified manner to
the one I have described and prefer to use. The arrangements herein set forth in the
various modified forms of apparatus, afford a convenient means or mode of introducing
the tar, and effecting complete or nearly complete gasification of the tar so introduced.
With reference to Figures 7 and 8 of the drawings, the arrangement therein
illustrated is one in which a single heated duct B is common to all the retorts of a
bench. In this design, A designates the ordinary retorts of a bench, B the heated
duct common to all the retorts A, C the seal chamber, and D, E cooled passages.
a¹ a³ are the ascension pipes and dip pipes respectively communicating between the
retorts A and the seal trough C. The retorts A are those in which the coal is distilled
in the usual way, and are set in
any known way.
Assuming the bench of retorts, illustrated in this example, to represent one of a
number of benches, having 4 or 5 retorts in each, then, mainly, all that is necessary
to do to render the existing retorts applicable for use in carrying out this Invention
is to introduce the heated duct B (or if 5 retorts exist remove the uppermost and
introduce the heated duct), and apply the seal trough and cooled passages, the other
details and parts being either retained or others used in their places, as may be
required or deemed expedient. The seal chamber C and cooled passages D, consist of a
horizontally arranged trough, and a passage descending from such trough, at right angles

page_text: to it, the whole being supported upon the upper end of the vertical entrance b of the
duct B, as in Figures 5 and 6. The liquid of the trough C, which will chiefly consist
of tar, ammoniacal liquor, and some watery liquors, is maintained in it, at a constant
level, by the wall of the passage d' and overflow pipes c; and the dip pipes a³ are
immersed in it, to a sufficient depth to seal them under working conditions.
It will be seen that, as set forth with reference to Figures 5 and by sealing the
pipes from the retorts as described, and providing a common outlet d to the common
heated duct B, no through communication between the trough or duct and the
retorts A exists, and that when any one or more retorts is or are opened for any
purpose, the escape of gas from the trough, back to the retort or retorts, is prevented,
and the process of distillation of the others is not impeded. On the upper end of the
cooled passage E at the exit end of the duct B, the outlet pipe F is placed, and the
passage itself is supported by the vertical exit portion b' of the duct B.
The operation process and effects of manufacturing gas in this apparatus are sub-
stantially the same as those already described with reference to the other Figures,
namely, the coal is placed in the retorts A. and distilled by beat in the ordinary way,
and the gas evolved from the coal is passed into the common seal trough C. Here it
deposits a part of its tar and condensable matters, such as ammoniacal vapours. It
then passes through the artificially cooled passage D, wherein further quantities of
the tar and other condensable matters in it are arrested. After leaving this passage,
the bulk then passes on to the heated duct B. In passing through the duct B the
whole of the gas is subject to the heat thereof, and the greater part of the non-
permanent portion of it is thereby rendered permanent. At the termination of the duct
the gas comes under the cooling influence of the artificially cooled passage E, and a
portion of the tarry or non-permanent vapours, still existing in the gas, are condensed
and arrested. The matters condensed in this passage, as well as the heavier portion
of those condensed in the passage D, fall back into the duct B, and in the presence
of freshly distilled gas from the retort A, are again converted into gas: the
ammoniacal and other lighter liquors condensed in the trough C are, however,
in this instance, drained away by a pipe c', which is placed at such a height in the
trough. or arranged in such a manner, as to drain them off, but so as to leave the heavier
matters, namely, mainly tar. This latter liquid boing the heaviest lies at the bottom
of the trough, and has to be raised over the lip of the pipe d¹ in order to get into the
duct B. This is done automatically as follows:-As soon as the head of liquid in the
trongh Creaches a certain level, the tar lying at the bottom of the trough is forced
under the lower edge of the pipe d, up between this pipe and the pipe d', and so on up
to the level of the lip of the overflow pipe d'. When it rises to slightly above this level,
it falls over the lip, and flows down to the lower edge thereof, from which it falls directly
on to the highly heated surface of the bottom of the duct B, or onto any red hot surface
of any media placed therein as described. The pipe d' is purposely made smaller than
either the passage D or the entrance b, so that the liquids falling from such pipe,
shall not in falling touch any portion of the hot duct which is not red hot, and
of sufficient temperature to gasify it, as previously described. The pipe d' is so
made that this end is obtained; and the lowest part of the passage D is contracted
at, whereby a like effect is obtained; that is to say, the matters condensed
within the passage D gravitate to the annular toe from whence they fall
directly onto the bottom of the duct B.
The ammoniacal liquor is led off from the seal trough C, as above described, in order
to prevent the temperature of the surface of, or in the duct B, into which the tar
drops, from falling below that necessary to gasify all or nearly all such tur. Were
the ammoniacal liquor admitted with the tar, this end might not be so effectively
obtained, as the extra quantity of liquor to be gasified or vapourized would
materially reduce the temperature of the duct at the said part into which it would
fall; also this liquor would be destroyed.
Any deposits that may take place in the ducts B, of any of the apparatus herein
described can be readily removed through the open end of the retort, which under
ordinary conditions is closed by the door b³.

page_text: The modification of apparatus illustrated in Figures 9 and 10 consists of the
arrangement of parts by which the gas can be diverted from its normal passage or
course through the duct B, shown in Figures 7 and 8, for the purposes set forth
with reference to Figures 5 and 6. For these purposes I provide a valve h', placed
and working in a valve case '. in which case are provided four openings or
apertures, communicating with the four pipes or passages h¹, h³, F and F, and by
means of which the gas coming from the retorts can be either caused to pass directly
from the chamber C to the outlet pipe F¹, or first through the duct B, and then
through the outlet pipe F¹. These pipes and passages are arranged as follows:-The
passage ¹ leads to the seal chamber C through the pipe d' of its trapped outlet,-
comprising the passage or pipe d' and the annular pipe d, previously described
the pipe leads to the cooling passape D of the duct B, the pipe F leads to the
cooling passage E; and the pipe F' is that by which the gas is led away from the
hench, namely the foul main; then if it he assumed the door of the duct B is
open or removed, and it is desired to divert the gas from its normal course or
passage, the valve is placed in the position shown in full lines in Figure 10,
whereby as it comes from the chamber C, it is short circuited through the outlet
pipe F, that is, it is passed directly from the chamber C, through the casing
of the valve, and out by the pipe F', without first being caused to pass through the
duct B. Now if the door of the duct be closed, and the gas is to take its
normal course through the duct B,-as set forth with reference to Figures 7
and 8-the valve his turned until it takes the position shown in dotted lines,
and the gas then passes from the chamber C, through the valve case ³ in the
direction shown by the arrows drawn in dotted lines; that is, it first passes by the
passages, valve case h³ and passage h³, and so on into the duct B, then from
the duct B it passes through the pipe F, valve case a second time on the opposite
side of the valve hand then away by the outlet pipe or main F.
The ammoniacal liquors deposited in the chamber C in this case flow away by the
pipe cas previously set forth; also the tar is caused to leave the chamber by the
trapped outlet in the same manner as already described with reference to Figures 7
and 8, but instead of falling directly from the pipe d¹ into the heated duct B, as set
forth with reference to those Figures, in this instance it first flows down the pipe d'
into the pipe h', from whence it gravitates by way of the valve case h³ into and
through the passage ³, and so onto the upper opening or aperture in the cooling
passage D, from whence it falls directly onto the red hot surface of or within the
duct B, as and for the purposes already described.
Although as stated this Invention can be applied in part or as a whole with
.advantage to existing gas making apparatus, yet at the same time it is evident that
it can be used and embodied in new works and with equally efficient results. And I
would also state that the Invention may be applied to single, "through," and other
known kinds of retorts and retort benches, and that the number and form of heated
ducts will necessarily be varied in applying the invention to suit the circumstances or
conditions of any particular application thereof.
Two extreme cases according to my Invention are herein given, as to the number
of heated ducts which may be employed in conjunction with the retorts; namely,
the one wherein each retort is provided with a hot duct, and the other wherein one
duct only is provided and worked in connection with all the retorts of a bench;
between these extremes any combination of ducts and retorts as to number and mode
of arrangement may be adopted.
Having thus fully described the said Invention, and the manner of performing the
same, I wish it to be understood that, although I have particularly described special
examples of apparatus for, and methods of producing illuminating gas in them,
nevertheless, I do not bind or confine myself to the special forms of construction of
the apparatus or parts thereof above described, for it will be evident to those skilled
in, the art of manufacturing gas and making gas manufacturing apparatus, the
several details or parts of the apparatus herein set forth and illustrated, and the exact

page_text: arrangement or disposition of them as well as their forms, may be varied without
departing from the nature, spirit, or scope of the said Invention; and further that
various combinations of parts of the several arrangements herein illustrated may be
made and used to carry out this Invention.
Moreover I no not confine or restrict myself to any particular quantities of tar that
may be introduced and gasified in the apparatus, nor the particular point or points
at which its introduction into the app iratus may be made, or means by which it is
introduced, or the precise mode of inixing the tar gas or vapour with the coal gus, or
the part of the apparatus at which it is combined with the coal gas, as these may be,
and will be varied, under varying conditions and requirements to suit such conditions
or requirements. On the other hand I wish it to he understood I do not claim the
application and use generally as separate things, of a heated chamber, duct or ducts
in connection with coal distilling retorts, or cooling passages, or broadly the making
of gas from tar which has been condensed from the gas made in the apparatus, as
these features, as separate things, have been heretofore proposed, but what I claim in
respect of the herein described Invention is :-
1. In the manufacture of illuminating gas, the herein described method of making
illuminating gas from the tar condensed or recovered from gas made in the gas
making apparatus, which method consists in causing the said tar to be delivered into
or to fall onto the red hot surface of, or a red hot surface within a heated chamber, or
duct, or ducts in the presence of freshly distilled gas, or through which such gas is
being passed.
2. In the manufacture of illuminating gas, the improvement herein described, in
the production of tar gas or vapour for mixing with coal gas, consisting of intro-
ducing tar into a heated chamber or duct (or a plurality of same) at a red heat, and
passing the gas or vapour so produced through an artificially cooled passage or
passages, for the purposes set forth.
3. In the manufacture of illuminating gas, an apparatus for vapourizing or
gasifying tar for the purposes specified, comprising a chamber or duct (or plurality
same) heated to a temperature such as herein specified, a means or device for
introducing tar into said chamber or duct, and an artificially cooled passage or
passages on or in connection with said chamber or duct, through which the tar gas or
vapour produced is passed upon leaving the apparatus, whereby pitch and other
condensable matters are arrested or condensed.
4. The manufacture or production of illuminating gas by distilling coal in closed
retorts (such as herein specified), and passing the gas so produced through a heated
chamber, duct, or ducts, and introducing tar into the apparatus in such a manner that
such tar is vapourized or gasified, and passing the products of distillation of the coal
and tar through an artificially cooled passage or passages on or in connection with the
apparatus, for the purposes set forth.
5. The improvement in the manufacture of illuminating gas from coal herein
described, which consists in distilling coal in closed retorts of ordinary or equivalent
type or construction, then passing such gas into a heated chamber, or duct, or ducts,
and introducing into such chamber, or duct, or ducts, tar condensed or recovered
from the gas made in the retorts, the said tar being thereby gasified in the presence
of freshly distilled coal gas, and the tar gas so produced and coal gas being thereby
passed together through, and subjected to the heat of the said chamber, or duct, or
ducts, wherein they become mixed, blonded, and rendered permanent.
6. The improvement in the manufacture of illuminating gas from coal herein
described, which consists in distilling coal in closed retorts of ordinary or other
equivalent construction, then passing such gas into a heated chamber, or duct or ducts,
and introducing into such chamber, or duct, or ducts, the tar condensed from the gas
made in the retorts, the said tar being thereby gasified in the presence of freshly
distilled gas, and the tar gas so produced and coal gas, being then passed together
through and subjected to the heat of the said chamber, or duct, or ducts, wherein

page_text: they become mixed, blended, and rendered permanent, then passing the said gases
through an artificially cooled passage or passages connected with said chamber, duct
or ducts.
7. The improvement in the manufacture of illuminating gas from coal herein
described, which consists in distilling coal in closed retorts of ordinary or other
equivalent construction, then passing such gus through an artificially cooled passage
or passages, then passing the gas into a heated chamber, or duct, or ducts, and
introducing into such chamber, or duct, o: ducts the tar condensed from the gas made
in the retorts, the said tar being thereby gasified in the presence of freshly distilled
gas, and the tar gas so produced and coal gas, then being passed together through,
and subjected to the heat of the said chamber, or duct, or ducts, wherein they becoine
mixed, blended and rendered permanent and then passing the said gas through an
artificially cooled passage or passages.
8. In a gas making plant in which a heated chamber, duct, or ducts, is or are
employed in conjunction with the coal distilling retorts, introducing the tar recovered
from the gas whilst in or after it has left the apparatus, into the heated chamber,
duct, or ducts of the apparatus, in the presence of freshly distilled coal gas coming
from said retorts, substantially in the manner herein described.
9. In a gas making plant in which a heated duct or ducts is or are employed in
conjunction with the coal distilling retorts, introducing the tar collected in a chamber
or trough connected with the said heated duct or ducts, or recovered from the gas, or
both, into the said duct or ducts in such a manner that it falls directly onto a highly
heated surface of or in such duct or ducts, for the purposes set forth.
10. A bench of coal distilling apparatus comprising a plurality of distilling retorts,
such as A, one or more heated ducts, such as B, and one or more artificially cooled
passages, said retorts being arranged together and said duct or ducts being disposed
in the upper part of the bench above the retorts, and connected by pipes, such as a,
to the retorts, and said cooling passage or passages being disposed on the heated duct
or ducts between the coal distillatory retorts and the gas exit passage.
11. In a bench of coal distilling apparatus, the combination of a plurality of
distillatory retorts A, ascension pipes a, a chamber C, artificially cooled passage D,
a heated duct B, and artificially cooled passage E, the said chamber, artificially cooled
passages, and heated ducts, being common to two or more of said retorts; operating
as or substantially as described.
12. In a bench of retorts in which a heated duct or ducts is or are employed in
conjunction with the coal distillatory retorts, the combination with the said duct or
ducts of a chamber, or trough, or troughs, in which tar is deposited, and gas from the
distillatory retorts is introduced, and a cooling passage or passages disposed between
the said chamber, or trough, or troughs, and the said duct or ducts.
13. In a bench of retorts in which a heated duct or ducts is or are employed in
conjunction with the coal distillatory retorts, the combination with the said duct or
ducts of a chamber, or trough, or troughs, into which gas from the distillatory retorts
is introduced, and in which liquor and tar is deposited, and a passage disposed between
the said chambor, or trough, or troughs, and the said passage, and the said chamber
or trough being provided with means or devices by which it and its contents are
artificially maintained in a cool condition.
14. In apparatus of the type hereindescribed, the combination of a chamber into
which tar or gas from the distillatory retorts, or either of them, is or are introduced,
with a heated duct, said chamber being in communication with the said duct by
a passage, and arranged above it, the tar being caused to fall directly from or
through the said passage onto a red hot surface of or in the duct, for the purposes
set forth.
15. In gas making apparatus of the type herein described, the combination of a
chamber to which tar and gas from the distillatory retorts, or either of them, is or are
introduced, a cooled passage, and a heated duct through which the gas made in the
retorts is passed, said cooled passage being interposed between the chamber and the

page_text: heated duct, and said chamber being in communication with the said duct arranged
above it, and provided with a passage through which the tar falls directly on to a red
hot surface of or in the heated duct.
16. The combination with a heated duct of a bench of gas making apparatus, of a
chamber C, having a trapped outlet d', by which the tar is conducted to the said bot
duct, and ammoniacal liquor excluded as described, and a cooling passage D;
substantially as set forth.
17. The combination with a heated duct of a bench of gas making apparatus, of
a chamber C, dip pipes a² for conveying the gas thereto, tar return pipe c², ainmoniacal
liquor outlet pipe c', and a trapped passage d' through which tar and gas is passed;
substantially as set forth.
18. In a bench of gas making retorts, the combination of a chamber (, common to
two or more retorts of the bench, and into which the gas from the retorts is passed as
described, a heated duc. B, and valve 4, interposed between the chamber C and the
duct, and provided with passages connecting with the said chamber, both ends of said
duct, and an outlet pipe, whereby the course of the gas from the chamber is either
directed through the said heated duct, or directly from the chamber to the said outlet
pipe; substantially as and for the purposes set forth.
19. The combination with a heated duct of a gas making apparatus, into which
duct the gas from the coal distillatory retorts, and tar, or either of them, is or are
introduced, a cooling passage D placed at the inlet end of such duct, and a cooling
passage placed at the outlet end thereof, said cooling passages being connected with
the duct and placed above it, whereby the matters condensed therein fall therefrom,
or are conducted onto a red hot surface of or in the duct; as or substantially as
set forth.
20. In a gas making plant in which a heated duct or a plurality of heated ducts
is or are employed in conjunction with coal distillatory retorts, the arrangement
substantially as herein described by which such heated duct or ducts is or are combined
with the existing or ordinary retorts of a bench.
21. In a gas making plant, the arrangement substantially as set forth by which
the existing retorts of a retort bench are each provided and combined with a heated
duct, such ducts being placed above the coal distilling retorts, or in the upper portion
of the bench.
22. In a gas making plant, the arrangement substantially as set forth by which
two ducts are each combined with two or more coal distilling retorts of a retort
bench, arranged according to the ordinary or existing methods, such ducts being
placed above the coal distilling retorts, or in the upper portion of the bench.
23. In the manufacture of illuminating gas, the system herein described of
manipulating and gasifying tar, and converting it into permanent illuminating gas,
which consists of condensing the tar from the gas made in a bench of retorts or set
of benches, in condensers belonging to and separated from the said bench or benches,
and bringing such tar back by gravity or mechanical force to the said bench or
benches, and re-introducing it into a heated chamber, or duct or ducts used in
connection with the retorts of each bench or set of benches, and through which the
gas being distilled by and coming from the retorts is being passed.
24. In apparatus for making illuminating gas, in which tar is introduced into a
heated duct or ducts employed for the purposes specified, the arrangement or
construction substantially as herein described, by which such tar is caused to move
or flow over, or be distributed over the heated surface of or in such duct or ducts.
25. In a gas making apparatus in which a heated chamber, duct, or ducts, is or
are employed in connection with one or more coal distilling retorts, and the gas made
in the retorts is passed through the said heated chamber, or duct, or ducts, introducing
tar into such chamber, duct, or ducts during the passage of the gas therethrough,
substantially as and for the purposes set forth.
26. In apparatus for the manufacture of gas from coal in which a heated duct or ducts
is or are employed, through which the gas made in the distillatory retorts is passed
and into which the tar is introduced, or either of them, the said duct or ducts not

page_text: being directly connected to or formed on the said retorts, but communicating
therewith, the employment of a cooling passage or passages on or in connection with
such duct or ducts and through which the gas is passed either before entering such
duct or ducts, or upon leaving same, or both before entering therein and upon issuing
therefrom.
27. In apparatus for manufacturing gas, a cooled passage placed on the mouth of a
retort or a heated duct (such as herein specified and illustrated in Figures 5 and 6)
the cooling surface of such passage being adapted to commence practically from the
entrance of said passage from the mouth of said retort or heated duct.
1
T
1400
JOHN H. R. DINSMORE.
By Cheesbrough & Royston,
15, Water Street, Liverpool,
Patent Agents.