Improved Methods of Producing Combustible Gases and in Apparatus therefor.
Year: 1888

page_text: Date of Application, 22nd Nov., 1888
Complete Specification Left, 22nd Aug., 1889-Accepted, 9th Nov., 1889
Improved Methods of Producing Combustible Gases and in
Apparatus therefor.
BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool in the County of
Lancaster Civil Engineer do hereby declare the nature of this invention to be as
follows:-
My Invention relates to improved methods of producing combustible gases and
consists as follows-
I utilise the horizontal or other retorts usually employed in producing illuminating
gas.
After the volatile gases have been driven off by heat; by means of special valves
fixed, preferably, in the ascension pipes, I pass superheated steam through the still
incandescent carbon or coke. The steam in contact with the incandescent carbon is
dissociated or split up, the oxygen combining with the carbon to form CO (carbon-
monoxide) the hydrogen being isolated. The gases by means of special reversal
valves are either led direct into the ordinary illuminating hydraulic gas main―or led
into a separate main.
I prefer to work two retorts simultaneously-one I fill with small broken pieces of
refractory material, so as to provide a considerable surface exposure to the passage
of any gas, through it, and which said retort I connect by passages to another retort,
in which carbonaceous fuel is stored.
I provide the necessary valvular arrangements by which the following cycle of
operations can be effected-Both the retorts being heated to a high temperature, the
evolved hydrocarbons (volatile) pass by a connection, into and through the incan-
descent material stored in the other retort, from which it passes to the hydraulic main.
When all the volatile hydrocarbons have been evolved, the special valves are reversed
simultaneously by which the steam is turned on and is compelled to traverse the two
retorts before escaping to the hydraulic main or otherwise.
In this arrangement the steam being introduced into the retort filled with refractory
broken brick or asbestos pieces-and which may have separated or scrubbed from the
volatile hydrocarbons-some suspended and unvolatilised portion of the heavy hydro-
carbons, the steam in its passage besides being superheated, splits up these deposits and
rearranges them, and carries forward the resulting gases therefrom into the second
retort through which in traversing the steam becomes dissociated as already described,
the resultant gases can be intermixed with the ordinary illuminating gas or be divided
therefrom by separate mains.
In a series of retorts I fix the necessary reversing valves in the ascension pipes
near to the upper bends and I provide the valves with a mechanical arrangement by
which the entire series can be simultaneously reversed.
COMPLETE SPECIFICATION.
Improved Methods of Producing Combustible Gases and in
Apparatus therefor.
BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool in the County of
Lancaster Civil Engineer 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 :-
My Invention relates to improved methods of producing combustible gases, and
consists as follows,→

page_text: After the volatile gases have been driven off by heat, by means of special valves
fixed, preferably, in the ascension pipes, I pass superheated steam through the still
incandescent carbon or coke in the retorts the steam in contact with the incandescent
carbon is dissociated or split up, the oxygen combining with the carbon to form CO.
(Carbonmonoxide) the hydrogen being isolated.
The gases, by means of special reversal valves are either led direct into the ordinary
illuminating hydraulic main or led into a separate main.
I prefer to work two retorts simultaneously, but 1 do not wish to be confined to the
use of two retorts only, may work three or more retorts simultaneously; in one of
the retorts I may place small broken pieces of refractory material-so as to provide
a considerable surface exposure to the passage of any gas through it, and which said
retort or retorts I connect by passages to another retort on which carbonaceous fuel
is stored.
1 provide the necessary valvular arrangements by which the following cycle of
operations can be effected.
Both the retorts being heated to a high temperature, the evolved hydrocarbons pass
by a connection into and through the incandescent material-coke fireclay or asbestos,
stored in other retort-from which it passes to the hydraulic main.
When all the volatile hydrocarbons have been evolved, the special valves are
reversed simultaneously by which the steam is turned on, and is compelled to traverse
the two retorts before escaping to the hydraulic main or otherwise.
In this arrangement the steam being introduced into the retort containing the
refractory pieces such as broken bricks-or it may be incandescent coke and which
may have separated or scrubbed from the volatile hydrocarbons some suspended and
unvolatilised portion of the heavy hydrocarbons, in its passage the steam besides being
superheated, splits up these deposits and rearranges them, and carries forward the
resultant gases therefrom into the second retort, through which in traversing the
steam becomes dissociated as already described-the resultant gases can be intermixed
with the ordinary illuminating gas or be divided therefrom by separate mains as desired.
In a series of retorts I fix the necessary reversing valves in the ascension pipes
near to the upper bend, and I provide the valves with a mechanical arrangement by
which the entire series can be simultaneously reversed.
Before referring in detail to the two sheets of drawings that accompany and are
intended to illustrate the nature of my said Invention; I wish it to be clearly under-
stood that I do not intend to be confined to the use of the exact details herein shewn,
as these may be modified considerably without departing from the nature of my said
Invention.
In sheet 1 of drawings, figure 1 is a back elevation of one bench of retorts con-
structed according to my Invention, figure 2 is a front elevation of same.
Referring to figure 1; it will be seen that all the retorts A, A1 and A2, are
connected to each other by pipe connections, rising from upper ends of retorts, and
provided with rotary valves B B1 and B2, any one of the set of three retorts can be
worked in conjunction with one or more of the other retorts, by a simple regulation
of the valves, for example the gases from A can be made to flow through retort A¹
by simply opening valve B closing valve B2 and opening valve B¹ and closing valve C
in ascension pipe.
The gases from A³ can be made to flow through retort A¹ by closing valve B,
opening valves B³, and B' and closing valve (in ascension main.
The gases from retort A' can be made to flow through either retorts A and A-or
through both retorts, by closing valve C¹ in ascension pipe and opening valves C
and Cin ascension pipes.
The steam, preferably superheated, by being led through a superheater coil in flue
leading from retort bench to chimney, is led to each retort by a pipe D placed either
centrally between the retorts-or alongside thereof-the passage of steam through
this pipe is regulated by a valve F-this main steam pipe is connected to each retort
by means of branch pipes F provided with cocks G.
The steam valves may be actuated by a chain passing around wheels on spindle of

page_text: regulating valve H-and around wheels on spindles of gas regulating valves so that
the reversal of the latter simultaneously effects the reversal of the steam valve.
The steam can be allowed to enter any one of the retorts-flowing through this
retort to the back end and returning to the front end through a second retort, in its
passage through both retorts the steam is more or less completely decomposed
according to the reactions 2 H₂O +2 C 4 H + 2 CO.
I prefer to adopt the following arrangement of turning on the steam-and producing
the gas technically known as water gas, after all the volatile hydrocarbons have been
driven or expelled from the fuel by heat-or within half an hour from the end of the period
required to effect this expulsion of the volatile hydrocarbons, absorbing say 5 hours.
Steam is then turned on to the incandescent coke remaining-the valves being so
reversed and regulated as to degree of opening, so that a pressure of steam is
established, the result being that the steam finds its way into the interstices of the
incandescent coke-converting same into gas by a sequence of well known reactions.
I prefer in working my invention, to follow the ordinary routine of working the
retorts in each bed in series. The precaution to be remembered is, that when steam
is passed through two retorts the carbonaceous material in both must be in a condition
of incandescence.
When the coal or cannel is charged into any one of the retorts, this retort should
be connected, by the opening of the valves in the manner already described, with one
of the other retorts, the material in which is in a state or condition of incandescence,
and through which in passing the volatile hydrocarbons-are freed from, or deposit
their tar or suspended liquid or solid hydrocarbon.
This tar, left behind in the retort is decomposed during the passage (and in contact
with the steam resulting in a mutual decomposition)-the resultant gases flowing into
the holder along with the water gas.
I enrich the gas by injecting into the incandescent fuel in the retorts-tar naptha-
line or any other liquid hydrocarbon. I may heat the liquid hydrocarbon by placing
the tank in which it is stored over the chimney flue leading from retorts to chimney.
In figure 2.-sheet 1 of drawings E represents the oil tank, in this application the
oil flows into funnels F, and from them falls or is injected into retort by pipes and
steam jet G connected to main steam supply pipe by connections and valves H, in
order to prevent the oil pipes from being choked with deposited tar. I maintain a
constant flow of steam through them.
Figure 3 on sheet 2 of drawings represents a longitudinal section of the retorts.
The arrangement of bafflers H H formed of refractory material, is intended to
partially superheat the steam and volatilise the oil that may be injected into the
retorts.
Figure 4 shews an alternative arrangement of steam and oil supply connection to
retort consisting of a movable radial connecting pipe J radiating from the main
supply pipe K, by this arrangement the steam and oil can be directed into the retort
in line with the axis thereof, and without interfering with the charging or withrawal
of material. Before taking of the lid the pipe J is swung on one side.
For heating the retorts, I prefer to employ either of the arrangements shewn-one
of which see figures 1 in sheet 1 of drawings and figure 3 sheet two of drawings,
consists of two chambers L and M, the M chamber being built immediately over the
other.
The gases produced from the fire in lower chamber flow through the fuel in upper
chamber and carbon monoxide gas is produced, which in combustion produces a
smokeless and lengthy flame encircling uniformly the retorts.
The fuel from upper fire falls on to the lower one through the long cavity N, any
unburnt fuel being quickly consumed in lower grates the ashes resulting fall into
water trough O.
The advantages of my invention may be briefly summarised as follows.
Any residual volatilisable-hydrocarbon left in the coke after the expiration of the
ordinary distillation period is in a degree decomposed or expelled and converted into
a fixed gas.

page_text: The ammonia left in the coke is also more or less completely expelled.
The production of tar is considerably reduced by the passage of the gases given off
at the commencement of distillation, through or over the incandescent fuel in the
second retorts.
A certain volume of heating or what is technically termed water gas may be pro-
duced after the ordinary illuminating gas has been expelled by heat, without reducing
the retorts too low in temperature.
Having now particularly ascertained the nature of my said Invention and the
manner in which the same may be performed, and having enumerated the advantages
of this invention I whish it to be distinctly understood that I do not clame the simple
application of steam to red hot or incandescent coke in a retort as this is not new-
but what I do claim is set forth as follows.
First The cycle of operations producing combustible gases as applied to gas
retorts of the ordinary kind-substantially as herein shewn and described.
Second-The arrangements for connecting the retorts to each other and the gas
and steam valves connected therewith-substantially as herein shewn.
Third The arrangement of converting one retort into a superheater in connection
with a second or third coal or cannel charged retort.
Fourth-The arrangements for simultaneously affecting the reversal of the steam
and gas valves.
Dad him teth
1000
B. H. THWAITE.