Im- COMBUSTIBLE GASES, PROVEMENTS IN THE GENERATION OR PRODUCTION OF AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1868

page_text: LETTERS PATENT to George Henry Benson, of Staley bridge, in the
County of Chester, Engineer, and William George Valentin, of the
Royal College of Chemistry, Chemist, for the Invention of "Im-
COMBUSTIBLE GASES,
PROVEMENTS IN THE GENERATION OR PRODUCTION OF
AND IN THE APPARATUS EMPLOYED THEREIN."
Sealed the 25th May 1869, and dated the 17th December 1868.
PROVISIONAL SPECIFICATION left by the said George Heury Benson
and William George Valentin at the Office of the Commissioners
of Patents, with their Petition, on the 17th December 1868.
We, GEORGE HENRY BENSON, of Staleybridge, in the County of
Chester, Engineer, and WILLIAM GEORGE VALENTIN, of the Royal
College of Chemistry, Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE GENERATION OR PRODUCTION OF
COMBUSTIBLE GASES, AND IN THE APPARATUS EMPLOYED THEREIN," to be as
follows:-
For the purpose of our Invention we employ a close vessel or
furnace built of refractory material, such as fire-bricks, ganister, or other

page_text: suitable material, and resting on columns; it may be built of a round,
square, rectangular, or other suitable form or shape, and be provided
with a hopper or hoppers for feeding the fuel.
We prefer to make the portion of the furnace or gas generator which
contains the upper portion of the fuel rectangular and oblong. The
sides are inclined inwards at their lower part, at an angle of about 45°.
These slopes or inclined planes are made of iron boxes, which can be
kept full of water, and may be constructed either of close or open
vessels.
The lower portion of the vessel or furnace is made by preference
circular, but narrower, and contains the most strongly ignited part of the
fuel. The blast is made to play directly upon it from several tuyeres
formed in water boxes, which by preference are made somewhat wedge-
shaped and forming segments of a circle. Thus the wall of this lower
portion-of-the-gas-generator is formed of the interior circular ends of
the water boxes, and-built-in-with-brickwork.
As the combustion of the fuel and the conversion of the same to
carbonic oxide proceeds the ashes therefrom accumulate and form what
is known as clinkers or solder. These clinkers constitute the most
formidable difficulty next to the caking of the fuel to the proper working
of a close gas generator, and the uniform generation of combustible
gases. If no water boxes are used this solder is liable to accumulate
before the tuyere openings, and has a tendency to stick to the brickwork
in ordinary furnaces, and when removed by poking breaks off bits of
bricks or furnace lining. We have discovered that this can be entirely
avoided by making the sides of the generator of one or several iron
boxes filled with water. In fact, we find it of advantage to allow the
solder to somewhat accumulate on this iron wall so as to form a coating
over it, which can be readily detached when required. This coating
checks the cooling effect of the water boxes, and keeps the clinkers or
solder in a semi-liquid state towards the centre of the fuel. In this
manner the fuel is kept sa much hotter and enables us to employ and
decompose more steam, which we can send into the furnace from
separate small steam jets.
For the purpose of withdrawing the clinkers or semi-fluid solder from
the furnace an iron box or receptacle is fixed or attached by any con-
venient means to the bottom of the vessel or gas generator, and the
clinkers can from time to time be removed from this box or receptacle

page_text: by any convenient contrivance, whilst the fuel remains supported by the
vault of solidified clinkers which forms below the tnyeres and above the
box, or may be held up by iron rods introduced through side holes. By
breaking up this crust by means of an iron bar the pasty mass of solder
may be allowed to fall or run down into the box, so as not to interfere
with the continuous generation of gases, from whence it can be removed
readily whilst the generator is working. The nozzles of the tuyeres are
kept free from clinkers or solder by introducing from time to time an
iron bar through the tuyeres and raking out the solder into a close iron
box or compartment bolted to the outer cast-iron casing, or forming part
of the tuyere pipe without interrupting the blast. Holes for poking the
fuel are also provided somewhat above the surface of the fuel on the
sides of the vessel where no water plates are, and likewise somewhat
below the water plates just above the water tuyere boxes. The gases
being under pressure rush out through these holes as soon as they are
thrown open, and a cross jet of air is therefore provided to drive them
away from the operator.
We prefer, in order to ensure a continuous and uniform mode of
generating combustible gases, that the fuel should be fed automatically.
To this end we prefer to employ a gas-tight winged wheel turned by a
shaft adapted to a closed hopper, so that the fuel can be supplied faster
or slower as may be required. The fuel so fed falls upon an inclined
plate or fuel guide, which can direct the falling fuel to one or the other
side of the vessel upon the inclined water plate iron bottom. The fuel
distils slowly off from one plate, whilst fresh fuel is fed upon the other
plate. The water plate prevents the small dust in the fuel from forming
a cake, and causes it to fall regularly towards the central part of the gas
generater. The hydrocarbon gases which are thus distilling off may be
passed directly into the gas mains, or they may be made to pass through
the ignited fuel downwards by turning a valve in the gas main, and thus
shutting it off whilst opening a side main, which we will call the carbonic
oxide main. This main commences from just below the well ignited
fuel, and joins the gas main above. In this manner we have it in our
power to prevent smoky gas, as the greater portion of the tarry matter is
decomposed by passing through well ignited fuel previous to the vapours
leaving the generator, and we are moreover enabled to check the volume
of gas which can be properly consumed in the furnace to which it is
taken for final combustion. "This is however only required when a rush

page_text: of hydrocarbon gases and tarry matter occurs, which sometimes takes
place after poking the upper portions of the fuel, but does not occur
with a free burning coal.
When the fuel is rich in hyrocarbons or when damp we sometimes
prefer to pass the gases through a cylindrical or other vessel or apparatus
filled with coke and kept ignited by an additional blast of hot air. Any
tarry matter thus becomes d. composed on its passage through the ignited
coke, and the flame in the furnace becomes improved.
It will be understood that different coals act differently in the
generator, as they contain moro or less volatile or gaseous matter; they
will therefore require different supplies of air, and varying depths and
breadth of fuel.
-Generators for making gas from caking coals do not require the
-inclined-planes, but_may_be_constructed with a central vertical-retort-to-
contain the fuel, and as this retort will be surrounded with highly heated
gases the volatile portions of the coal will be distilled off to a great
extent before the fuel is pushed down into the gas generator proper
below.
SPECIFICATON in pursuance of the conditions of the Letters Patent,
filed by the said George Henry Benson and William George
Valentin in the Great Seal Patent Office on the 17th June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
HENRY BENSON, of Staleybridge, in the County of Chester, Engineer,
and WILLIAM GEORGE VALENTIN, of the Royal College of Chemistry,
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of December, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs, and successors, give
and grant unto us, the said George Henry Benson and William George
Valeutin, Her special licence that we, the said George Henry Benson
and William George Valentin, our executors, administrators, and assigns,
or such others as we, the said George Henry Benson and William George
Valentin, our executors, administrators, and assigns, should at any time

page_text: "
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
Inake, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE GENERATION OR PRODUCTION OF COMBUSTIBLE GASES,
AND IN THE APPARATUS EMPLOYED THEREIN,' upon the condition (amongst
others) that we, the said George Henry Benson and William George
Valentin, our executors or administrators, by an instrument in writing
under our, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said George Henry Benson and William
George Valentin, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, reference
being had to the Drawing hereunto annexed, and to the letters and
figures marked thereon (that is to say)
In carrying out our Invention of "Improvements in the Generation
or Production of Combustible Gases" we employ a close vessel or
furnace built of refractory material, such as fire-bricks, ganister, or other
suitable material and resting on columns. It may be built of a round,
square, rectangular, or other suitable form or shape, and be provided
with a hopper or hoppers for feeding the fuel. We prefer to make the
portion of the furnace or gas generator which contains the upper portion
of the fuel rectangular and oblong. The sides are inclined inwards at
their lower part at an angle of about forty-five degrees. These slopes
or inclined planes are sometimes made of iron boxes, which can be kept
full of water, and may be constructed either as close or open vessels.
The lower portion of the apparatus is made, by preference, circular, but
narrower than the upper part, and contains the most strongly iguited
portion of the fuel. The blast is made to play directly upon it from
several tuyeres formed in water boxes, which by preference are made
somewhat wedge-shaped and form segments of a circle. Thus the wall
of this lower portion of the gas generator is formed of the interior
circular ends of the water boxes. The size and particular form of the
gas generator will depend in a great measure upon the nature of the

page_text: fuel to be operated upon. We shall describe generators suitable for
operating upon three varieties of fuel, viz., non-caking or free burning
coal, ordinary coal, and caking coal.
In the accompanying Drawings, Fig. 1 is a transverse vertical section
of the kind of generator we use for free burning non-caking coals,
Fig. 2 being a longitudinal vertical section of the same with the purifier
attached it is a close apparatus A, A, consisting of a casing of
wrought-iron plates supported on cast-iron standards B, B, about six
feet from the ground and lined with fire-brick, a bed of sand being
placed next the plates to keep all gas-tight. The air to support com.
bustion is supplied in the form of blast produced by any suitable blast
engine, blower, or fau, and is brought from the blast engine by means
of a pipe to the air main C, C, which is carried round the generator
Feither outside, as-shewn-in-the-Drawing, or it may be enclosed within
the brickwork. This-air-we-prefer-to-be-heated-by-the-waste-heat-of
the furnace. From the air main C are separate connections to each of
the tuyeres D, D, which are placed at equal distances round the gene-
rator. These tuyeres are strong wrought-iron pipes fitted into cast or
wrought iron boxes E filled with water; these boxes may be either open
or close vessels, and are in connection with a reservoir which will supply
the water evaporated from them. These boxes form the lower portion
of the generator in which the carbonic oxide is produced. The tuyeres
D, D', may be arranged in one, two, or more rows, but we find that two
rows are sufficient for most purposes. The lower tuyeres D or "solder"
tuyeres act on the partly ourn coke and ash and reduce it into a semi-
pasty-like mass called "solder," which will run away into the lower
portion of the cylindrical chamber and allow fresh fuel to fall to the
tuyeres. The top row or gas tuyeres 11 convert the coke into carbonic
oxide and act freely, as solder will not have time to form and obstruct
them, but should any form it will be rapidly pressed down by the fuel
above aided by the action of the tuyeres below. A portion of the gas
made below is iguited by the air from these gas tuyercs, but is converted
again into carbonic oxide by passing through the layer of hot coke above
the gas tuyeres.
In the generator, shewn at Fig. 1, there are six top tuyeres and six
bottom tuyeres placed at equal distances round the generator, but not
in a line above each other. The tuyere pipes at the outside of the water
boxes turn up, and at the angle are placed boxes c, d, for holding any

page_text: solder that may stick to the poking bar on withdrawing the same after
poking the fire. This requires to be done perhaps once every fifteen
minutes. These boxes d can be emptied through the sliding door below.
The top tuyeres do not require these boxes, as any solder that may be
formed may be pushed inside. The poking bars are introduced through
a sliding door d at the end, or by withdrawing a wooden or other
plug in the door d. Each tuyere is provided with a separate tap
or valve d³, so that the volume of air can be changed and regulated
as may be required. Where the tuyere pipes touch the fuel they may
be contracted by a nozzle d', which can be easily removed from the
.outside through the tuyere pipe when not required. The refuse ash,
clinker, or "solder" made by the melting of the dirt in the fuel falls
from the tuyere mouths on to the moveable plate F, and when the space
is filled with a fused mass which impedes the working of the solder
tuyeres the plate F is lowered say two inches by altering the position
of the peg g in the rod G a hole higher so as to let the plate down.
In process of time, say twenty-four hours, the whole space in which
the plate works will be filled up with "solder." The air must then
be shut off and horizontal bars are introduced through the holes f. f,
so as to hold up the fuel. The solder can then be withdrawn through
the door H, as it will be cold and brittle and will not stick to the
smooth iron as it would to brick. The plate F will then be placed
in its original position and the bars withdrawn from the holes f and
all made tight by means of a closely fitting door, and the generator
will again be in working order. In the usual generators the operation
of clearing away the solder causes considerable interruption several
times a day, but in our improved generator it is effected in a few
minutes, leaving the generator quite free from solder, except a thin
layer to protect the moveable plate F. This moveable plate is provided
with a scraper I to keep the plate in position and to scrape off any
pieces of solder which might otherwise fasten the plate for a time
against the tuyere boxes and thus impede its free working. The plate F
can be easily moved up and down by means of the lever K so as to
break up any air holes in the hot fuel and prevent the air from passing
through the coke without forming gas. It will also prevent any solder
from sticking to the boxes E, which would cause the fuel to remain
up and not fall gradually to the blast. The movement of the plate F
will thus save poking the fuel above, which is an evil, inasmuch as
it disturbs the action of the slow distillation. Just above the ping the

page_text: The
central rod G of the plate F is divided into two parts, and is fitted
together by a socket joint g', so that by withdrawing the connecting
ping it can be turned round by a lever L fitted into a projecting
pin g³ on the socket g³ so as to bring a different surface of fuel to the
action of the blast. If preferred a cog wheel might be attached to
the rod G, which could then be turned by a worm on a shaft driven
by the engine, so that a constant motion can be maintained. The
bottom plate F can thus be made to revolve once every hour, and
when it is wished to stir the fuel the pin g² can be inserted and the
plate F can be raised once or twice; but in practice we find that with
the right sort of fuel (and if the tuyeres are kept open) this is very
seldom required. The fuel is fed into the generator either by a hopper
and plug arrangement, as at N, Figures 1 and 2, or by a feeding
apparatus M, which consists of a rotating wheel m fitted with wings
_and_made to rotate in a box or cylinder at the bottom part of a hopper,
-so-that-at-every-sixth_part_of_a_turn_of_the feeding wheel m a certain
small portion of the fuel will be dropped into the generator.
wings of the rotating wheel fit at the bottom gas-tight, and are fixed
on a shaft which carries on its end a worm wheel m' which is driven
by a worm m² fixed on a shaft driven by the fan or other engine.
By this means a regulated and continual stream of coal is always-
dropping into the generator. If large coal be used a pair of rollers
placed above will break the coal before entering into the compart-
ments of the rotating wheel m. The hopper can be made large enough
to contain several hours supply, or it can be continually fed by means
of buckets placed on endless bands so arranged that in passing over the
top shaft they will empty their contents into the hopper. The hopper
and plug arrangement seen at N is not used, except when first starting
the generator or for letting in large quantities of fuel at a time. It is
provided with a close top to prevent the gas from escaping when the
plug n is lowered. The fuel from the feeder falls on to a conical plug O
which will spread it equally all round the generator on the surface and
to the outside of the previously filled fuel. This plug is capable of being
moved up and down by means of a rod P provided with a lever which
acts on the stem of the plug O. The outer end of the rod P is provided
with handles for turning it, and is fitted with a ratchet and catch to hold
it in position. The plug O is also capable of being Loved backwards
and forwards laterally by means of a rod Q. Practically when once set
the plug O needs no alteration in position provided the same kind of

page_text: fuel be used, but if from any cause it is found advantageous to work the
fuel at a different height the manner of throwing in the coal must also
be altered. The fuel inside the generator thus forms a sort of circular
inclined plane or hollow inverted cone, the lower portion of which is
being slowly distilled off and gradually sinks to the hot fuel in the
centre, the fresh added fuel taking its place at the top of the plane. The
raw fuel by falling to the outside prevents the air from stripping up the
sides and so lighting the gas at the surface; it also prevents the brickwork
from being eaten away. The hydrocarbon and carbonic oxide gases are
passed direct to the main pipe R or through a purifier which will be
hereafter explained. When sent direct to the main R the gases escape
by the opening a into a vertical flue b, which opening a may be closed
by a valve c worked by the rod d and lever 71, and may be held in
position by a pin 2 in the pendent rods d3. Below the surface of the
fuel there is another exit aperture e provided with a valve f* which is
worked by the same rod and lever as the valve c above. This lower
aperture e we call the carbonic oxide flue, and it is used when the top
fuel is becoming too much burnt through, or when we want to stop a
sudden flush of gas. Should a sudden evolution of gas occur we are
enabled to prevent these evils without stopping the volume of gas or
arresting the blast or stopping the action of the feeder. This can be
effected by simply raising the rod d* and shutting the top fuel a, at
the same time opening the bottom flue e, and thus forcing the gases to
descend through the hot fuel, whereby the tarry matters being obliged by
pressure to descend will be converted into gas and the flame will be
clear and the volume of gas the same in the furnace as if nothing
abnormal had occurred. When the sudden flush of gas is over the
valves are replaced as before and all goes through the opening a, With
some coals we find it advantageous to always allow this carbonic oxide
flue e to be a little open, as it causes a more even distillation of gases.
Sometimes we have three or more carbonic oxide flues opening into the
sides of the generator and all coming into one flue and worked by the
same valves. This plan is generally adopted when the coals require the
valves to be always left partly open, as noticed above. The reason of
this is. that when for a length of time the carbonic oxide is drawn from
one portion of the fuel, that fuel will be worked better than the others,
and will thus cause unequal production of carbonic oxide in the lower
parts of the generator. For cleaning these openings holes are provided
and fitted with plugs h, which being loosely filled in with clay act as

page_text: safety valves for the generator. In addition to the valves c and f*
there are stop valves j, k, (also worked by means of a lever and rod) for
regulating the amount of gas to the furnaces. The two flues a, e, being
exactly of the same size each can be partly closed without interfering
with the action of the carbonic oxide valve arrangement. In working
we have found it advantageous to keep these valves j, k, a little closed
so as to create a pressure within the generator, and so therefore if any
tuyere plug is opened for poking the fuel the supply of gas will not be
interfered with. The upper part of the generator forms a reservoir for
gas, andthus prevents intermittent supplies of gas to the furnaces if from
any cause the generator should cease femporarily to produce the regular
supply. It also keeps the tarry matters in the generator, and prevents it
from filling the pipes and choking them. The valves for the carbonic
oxide flues and the pressure_valves_can_be_arranged in any convenient.
-manner-in-some-of-our-generators-;-for-instance,-the-two-flues-rise-to-a-
level and are closed by cone or bell valves; these we may remark are
specially useful if there be a large quantity of tarry matter in the fuel,
in which case the sliding valves would be liable to stick and be difficult
to work. Poking holes 1, l, are made in the form of long slits, and
are placed at various heights in the generator. These holes or apertures
are provided with air pipes P,. the blast from which will prevent the
escape of gas through the holes and will protect the hand of the
workman from the flame that would otherwise issue. These arrange-
ments will very seldom require to be used if the generator be in working
order, as the lower fuel, if any, will require the most poking, aud that
can be best done by raising and lowering the moveable plate F as above
described. Steam can also be introduced by the pipe S, and this steam
may be superheated by passing it through pipes built into the brickwork
as at T.
Fig. 3, Sheet II., is a vertical section of another generator which
differs from that shewn at Figures 1 and 2 as regards the mauner in
which the gases are distilled off from the fuel. This form of generator
is intended for coal of a slight caking nature, but it can also be used
for any description of coal. The hopper N and feeding apparatus M
are placed side by side near the middle of the top of the generator
the fuel falling from the hopper or feeder on to a long moveable
plate U which is capable of turning on centres so as to direct the
fuel to either side of the arch V on to the inclined plates W. These

page_text: inclined plates W are made in the form of hollow boxes, and are supplied
with water like the close tuy ere boxes in Figure 1 and 2. The water
is admitted to them at w, and the steam evolved by the heat escapes
at w¹. These water boxes W being cooler than other parts of the
generator the partially distilled fuel will be prevented from sticking
thereto, but will gradually slide down into the lower portion of the
generator. After feeding the fuel on to one of the plates W for a
short time, say six or eight minutes, the directing plate U is turned
on its centre into the reversed position, and the fuel will be dropped
on the other side of the arch V on to the other water plate W. In this
manner the gas from the fuel will have time to remain quietly distilling
off and there will be room for the fuel to swell. The directing plate U
can be worked by mechanical means by a wheel made to revolve once
in any given time, and can be provided with a knock-off and reversing
motion gear.
The gases from the coke, consisting of carbonic oxide, as
described with reference to Figures 1 and 2, together with the top gases
and tarry matters, will pass to the main R through the top opening a
or through the carbonic oxide opening e, as in Fig. 1. If in either
of the generators it be desired to send the gases through the purifier
the valves X and Y, Fig. 2, are opened, and the gases will rush down
the interior flue Y' into the purifier Z, and after passing through, this
purifier it goes through the opening X' into internal flue X and
upwards through the two-way valve X' into the main R. At the
bottom of the downward internal flue Y' there is a cleaning out
chamber provided with a door. The purifier Z is formed of a strong
iron cylinder, and is in fact a small generator lined with brick and
with a layer of sand next the plates; this purifier is fed by a hopper,
and can be cleaned out through a door at the bottom. It is filled
with hard coke, and is blown up to a white heat by means of three
or more air tuyeres o placed round the bottom, which can either be
taken out to be cleaned, or it may be a fixture, or the bottom can be
formed of a water box like the generator. The carbonic oxide produced
in heating up the purifier is conducted through the valve X into the
flue X2. The valve X³ is raised a trifle so as to allow the gas to pass
into the main flue R, where it mixes with the gas from the generator.
When the coke in the purifier is hot the gases from the generator are
turned through it by passing through the opening X', as described above.
The air from the tuyeres will act upon the gas and tarry matters and
burn them, but having to pass through the layer of hot coke it will

page_text: portion of the generator for the production of carbonic oxide gas.
The particular dimensions of the generator vary with the various sorts
of coal and the number of furnaces it is intended to supply. The
gases from the mains are carried to the furnace either direct to the
flues or tuşeres or are heated by being passed through a stove heated
by the waste heat of the furnace or in any other convenient manner.
Having now described our Invention of "Improvements in the
Generation or Production of Combustible Gases, and in the Apparatus
employed therein," and having explained the manner of carrying the
same into effect,-
We claim as the Invention secured to us by Letters Patent as afore-
said constructing generators for the production of combustible gases in
the manner herein set forth.
We claim particularly constructing the lower part of the generator of
hollow boxes filled with water as and for the purpose above described.
We also claim the adaptation to our improved gas generators of the
devices above described for feeding in the fuel and distributing it in
the generator.
We further claim the devices herein set forth for conducting the gases
(as they are generated) from different parts of the generator either
direct to the main or to a purifier, whereby the tarry matters, smoke,
and uncombined carbon will be converted into clear combustible gases.
We also claim the use of the boxes or chambers with their accessories
at the bottom of the furnace for the purpose of receiving the solder
and incombustible parts of the fuel, so that such parts may be removed
from the apparatus without stopping or materially interfering with
the process of distillation.
In witness whereof, we, the said George Henry Benson and William
George Valentin, have hereunto set our hands and seals, the
Eleventh day of June, in the year of our Lord One thousand
eight hundred and sixty-nine.