IMPROVEMENTS IN THE MANUFACTURE OF 'WATER GAS' AND IN APPARATUS EMPLOYED IN SUCH MANUFACTURE
Year: 1882

page_text: LETTERS PATENT to John Clayton Mewburn of 169 Fleet Street in the
City of London Patent Agent and Consulting Engineer for an invention of
"IMPROVEMENTS IN THE MANUFACTURE OF 'WATER GAS' AND IN APPARATUS
EMPLOYED IN SUCH MANUFACTURE" A communication from abroad by
George Spring Dwight of New York United States of America at present
of Homburg vor der Höhe Germany
PROVISIONAL SPECIFICATION left by the said John Clayton Mewburn at
the Office of the Commissioners of Patents on the 22nd April 1882.
JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London, Patent
Agent and Consulting Engincer "IMPROVEMENTS IN THE MANUFACTURE OF
[A com-
'WATER GAS' AND IN APPARATUS EMPLOYED IN SUCH MANUFACTURE
munication from abroad by George Spring Dwight of New York United States
of America at present of Homburg vor der Höhe Germany.]
The communicator to me of this invention has discovered that in compound
furnaces, consisting of more than one chamber or compartment, where steam is
superheated in one part and sent into the other for decomposition with carbon,
there is a liability of the steam to pass through the brick partition walls
commonly employed and this liability increases in proportion to the temperature
of the steam and the pressure. This fact applies also to the air blast under some
conditions though in a less degree. The result is that the conversion of the carbou,
whether by the oxygen of the air of the steam, is not so systematic and constant
in the highest economic sense as it would otherwise be.
The only alternative by which the best results can be secured and this difficulty
be avoided, is to separate the different compartments by impervious metallic plates
in the partition walls, or to relate them to each other so that no partition walls
shall be needed.
Every consideration renders the latter plan the best and I hereinafter describe a
construction which perfectly overcomes the difficulty mentioned.

page_text: This construction is an example, the vertical and horizontal relationships of the
chambers may of course be varied to suit local conditions.
The said communicator has also discovered that at the high velocities involved
in, the rapid generation of gas and the refractory nature of fire brick, it is difficult
to absorb all the heat of combustion in the regenerative chambers, especially if the
carbon is burned to carbonic oxide in the producer or coal chamber and then
burned to carbonic acid in the regenerative chamber. Consequently the products
of combustion escape from the furnace at too high a temperature and economy
domands that this heat should be utilized.
I lead all the gaseous products of the furnace through the water of a boiler
specially constructed for this purpose, and wherein also may be burned, if need
be, some of the combustible products of said furnace as hereinafter more fully
explained.
The said communicator has also discovered that in using fuels containing much
ash a grate is desirable to sift the same out of the fire chamber but if a grate is
employed as ordinarily, i.e. with the blast and hot gases passing alternately through
it, it is soon burnt out.
If on the other hand hydraulic grates are used, these chill the slag descending
through them and in consequence-tho-spaces between the bars become choked up
greatly impeding the operation. This invention, therefore comprises-a-construction
by which the blast enters the coal above the grate so that it is not exposed to a
high temperature.
And to protect the edges of the brickwork at the point where the combustion is
most intense a water ring or square is employed which can be put in position or
removed to the exterior without taking the furnace apart.
The entire furnace which I will now proceed to describe is enclosed in an iron-
_shell or casing made steam tight in all its parts.
A generator and a regenerator both substantially built of fire brick are connected
with each other by a passage. The generator contains a fire-chamber-wherein fuel
is burned with air or steam. The regenerator is filled with loosely arranged fire
bricks. The generator has a charging hole at the top for introducing fuel, and
3 stoking doors, also an ash pit with 2 doors giving access thereto-The 3 stoking
doors give access to the base of the fire chamber through corresponding passages.
The brick walls at the points of intersection of these passages with the fire
chamber are protected from the destructive influence of the fire by an iron square
or ring through which water is constantly passing This square or ring is made in
halves which can be put in place or removed to the exterior by means of a
removable plate.
By means of pipes these halves can be connected with each other and with the
boiler or other water supply and a regular flow of water be secured and the heat
imparted to the water can be economically utilized.
From the end of the regenerator a pipe leads directly into the boiler and
connects with a pipe which traverses the entire length of the boiler and by means
of a vertical branch at the other end connects with a space. There is a sliding
cover at the outer opening of the branch. The main pipe extends through the
ends of the boiler and can be gut at for cleaning internally by means of removable
plates at the ends. Above the space above mentioned is a tubular water heater.
There is another water heater over a space at the other end of the boiler and
above this heater is another space having an outlet pipe and a valve The space
below this second heater is connected with a pipe which traverses the entire length
of the boiler and connects with a hydraulic main or valve.
This pipe like the other pipe which traverses the boiler is accessible for cleansing
by means of removable plates outside the ends of the boiler. The hydraulic main
or valve is connected with the base of the generator by a pipe and is provided
with a changeable clack or valve working vertically. A branch from a blast pipe
leads air into the base of the generator by means of the last named pipe Another
branch conducts air to an opening above the passage between the generator and

page_text: regenerator. A third branch supplies air to the pipe lending from the regenerator
to the boiler. There is a fire space beneath the boiler, wherein if needed, coal or
gas may be burned; there is a space for the escape of the products of combustion,
and a flue or outlet for them to the space below the first named water heater.
A door gives access to the end of the regenerator.
The method of operating this furnace is as follows:-
A fire is kindled on the grate all the openings being shut except the door at the
end of the regenerator and the doors opening into the ash pit. When the furnace
has become somewhat warmed, the depth of fuel in the fire chamber can be increased
all the openings to the furnace are closed except the cover to the branch pipe
lending to the space below the first described water heater. Air is driven in by
the first described branch from the blast pipe to the fire space between the water
ring and the gate and passing through the coal goes over into the regenerator in
the form of hot gases. These passing through the loose bricks therein, deposit their
sensible heat, together with heavy vapours and atomic carbon. A considerable
percentage of combustible gas (CO) still remains unconsumed and this is utilized
by igniting it with a second blast of air sent into the connecting pipe between the
regenerator and the boiler by means of the third described branch pipe. This
causes combustion to ensue in the main pipe in the boiler which traversing the
boiler beneath the surface of the water, imparts to the water its heat and the
resulting gases now entirely non combustible passing through the branch into the
space above, rise thence through the tubes of the water heater parting with their
sensible heat to the water surrounding them, and escape at a low temperature into
the open air.
When sufficient heat is attained in the furnace and sufficient steam generated in
the boiler, both the air blasts are shut off, sufficient steam is let in to expel the
products of combustion remaining in the furnace and the boiler pipe and these
non-combustible gases are thus prevented from mixing with and diluting the
combustible gases subsequently made. The cover of the branch pipe below the
first water heater is then closed and the hydraulic valve is opened by being lifted.
Steam is then let into the branch pipe last named and passing through the main
boiler pipe enters the regenerator and passing through the hot bricks, becomes
highly superheated and entering the generator through the intermediate passage
comes in contact with the glowing coals; a mutual decomposition of the carbon and
steain occurs, forming what is called "water gas." This escapes from the base of
the generator into and through the hydraulic main into a pipe which conducts it to
the second pipe which traverses the boiler. Passing through this pipe it imparts its
heat to the water and issuing from the boiler into the space below the second water
heater rises upward through the tubes of this heater yielding most of its remaining
heat to the water therein and passing out of the upper space and through the pipe
and valve before described at a low temperature goes to the holder or place of use.
After a sufficient flow of gas has taken place, the steam is shut off, the hydraulic
valve is closed the cover is removed from the branch pipe below the first water
heater sufficient steam is admitted to expel the combustible gas remaining in the
generator, coal is added if required, any necessary stoking is done, through the
various doors and the process before mentioned is repeated. If it is desired in
making gas to utilize tars or other semi-fluid or fluid or granulated hydro-carbons
such materials can best be introduced by the opening leading into the passage
between the generator and regenerator by such devices us may be suited to the
peculiarities of the substance used. But as it is found that some of these materials
have a tendency to burn to a species of coke if used in the presence of superheated
steam, in the said opening which thereby becomes obstructed, I therefore introduce
at the proper time air into this opening by means of the branch blast pipe con-
nected therewith as before described so that an active combustion ensues and the
opening is freed of the inaterial clogging it. The opening may be simply covered
with a plate which can be removed to give place to any device adapted to the
materials which it is designed to inject at that point. A quite novel use may be

page_text: made of such forms of fuel when it is desired to economize the fuel burned on the
grate, as follows:-After the furnace has been sufficiently heated and is being
worked with air blast, the blast may be partly or entirely shut off at the first
described branch so that little or no air shall pass upward through the coal in the
fire chamber and the blast in the second described branch being opened air is driven
in through the opening leading to the passage between the generator and the
regenerator, and fluid, semi-fluid or granulated fuel is simultaneously fed into this
opening and mingling with the air burns actively in the regenerator. Any com-
bustible gases or fuel materials passing out of the regenerator by the pipe leading
to the boiler are burned by the blast from the third branch as before described.
But a considerable portion of the fuel thus carried in remains unconverted or
partially converted and being distributed in a finely divided form among the
crevices of the regenerator and at a high temperature is in the most favorable
condition for rapid decomposition with the steam subsequently admitted. Any ash
remaining can be cleaned out by blast or otherwise through the door at the end of
the regenerator. In the manufacture of water gas heretofore, fluid or granulated
fuel has been fed to the furnace only in connection with a blast of superheated
steam-and-never with air blast as just described By combining these two methods
a continuous-use-of such economic forms-of fuel may be secured.
If two generators be employed the operation of gas making is rendered
practically continuous, one furnace blowing with air, while the other blows with
steam, by which means the working of the boiler and the supply of steam are
regular and constant. The radiating heat from two sides of the regenerators acts
upon the boiler-and-if-further heat is required in getting up or maintaining steam
it is obtained by either a coal or gas fire boneath the boiler. Of course a single
generator may be built upon the same general principle

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Clayton Mewburn in the Great Seal Patent Office on the
21st October 1882.
"
JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Patent
Agent and Consulting Engineer "IMPROVEMENTS IN THE MANUFACTURE OF
WATER GAS AND IN APPARATUS EMPLOYED IN SUCH MANUFACTURE (A com-
munication from abroad by George Spring Dwight of New York United States
of America at present of Homburg vor der Höhe Germany)
The Communicator to me of this invention has discovered, that in compound
furnaces, consisting of more than one chamber or compartment, where steam is
superheated in one part and sent into the other for decomposition with carbon the
steam is liable to pass through the brick partition walls commonly employed and
this liability increases in proportion to the temperature of the steam and the
pressure. This fact applies also to the air blast under some conditions, though in a
less degree. The result is that the conversion of the carbon, whether by the
oxygen of the air or the steam, is not so systematic and constant in the highest
economic senso as it would otherwise be.
The only alternative by which the best results can bo secured and this difficulty
be avoided, is to separate the different compartments by impervious metallic plates
in the partition walls, or to relate them to each other so that no partition walls
shall be needed.
Every consideration renders the latter plan the best and I hereinafter describe a
construction which perfectly overcomes the difficulty mentioned.
This construction is an example; the vertical and horizontal relationships of the
chambers may of course be varied to suit local conditions.
The said communicator has also discovered that at the high velocities involved
in the rapid generation of gas and the refractory nature of fire brick, it is difficult
to absorb all the heat of combustion in the regenerative chambers, especially if the
carbon is burned to carbonic oxide in the producer or coal chamber and then
burned to carbonic acid in the regenerative chamber-Consequently the products
of combustion escape from the furnace at too high a temperature, and economy
demands that this heat should be utilized.
The said communicator proposes to lead all the gaseous products of the furnace
through the water of a boiler specially constructed for this purpose and wherein
also may be burned if need be, some of the combustible products of said furnace,
as hereinafter more fully explained.
The said communicator has also discovered, that in using fuels containing much
ash a grate is desirable, to sift the same out of the fire chamber, but if a grate is
employed, as ordinarily, i.c. with the blast and hot gases passing alternately
through it, it is soon burnt out.
If on the other band hydraulic grates are used, these chill the slag descending
through them and in consequence the spaces between the bars become choked up,
greatly impeding the operation. This invention therefore comprises a construction
by which the blast enters the coal above the grate, so that it is not exposed to a
bigh temperature.
And to protect the edges of the brick work at the point where the combustion
is most intense, a water ring or square is employed which can be put in position or
removed to the exterior without taking the furnace apart.
The entire furnace which I will now proceed to describe with the aid of the
annexed drawings illustrating the same is enclosed in an iron shell or casing, made
steam tight in all its parts.

page_text: A is a generator and B a regenerator, both substantially built of fire brick and
connected with each other by a passage V. The generator A contains a fire or
combustion chamber I wherein fuel is burned with air or steam. The regenerator B
is filled with loosely arranged fire bricks. The generator A has a charging hole X
at the top for introducing fuel and three stoking doors P P P', also an ash pit J
with two doors P P giving access thereto. The three stoking doors give access
to the base of the chamber I through the passages M M and M. The brick walls
at the points of intersection of these passages with the chamber I are protected
from the destructive influence of the fire by an iron square or ring K K through
which water is constantly passing. This square or ring is made in halves which
can be put in place or removed to the exterior by means of a removable plate L.
By means of pipes Z these halves can be connected with each other and with
the boiler or other water supply and a regular flow of water be secured and the
heat imparted to the water can be economically utilized.
From the end of the regenerator a pipe F leads directly into the builer C and
connects with a pipe G which traverses the entire length of the boiler C and by
means of a vertical branch G' connects with a space T. X is a sliding cover at
the outer opening of G¹. The main pipe G extends through the ends of the boiler
-and-can_be_got at for cleaning internally by means of removable plates at the ends.
Above-the space T is a tubular water-heater-D. D₁ is another water heater over
a space T¹ and above this heater is another space-T having an outlet-pipe-Q-and-
a valve Y. The space T¹ is connected by means of the pipe H' with the pipe H
which traverses the entire length of the boiler and connects with the hydraulic
main or valve E. This pipe H like the pipe G is accessible for cleansing by
means of removeable plates outside the ends of the boiler. The hydraulic main or
valve E is connected with the base of the generator-by-the-pipe O and is provided
with a changeable clack or valve E! working vertically S is a blast from which a
-branch S¹ leads air into the base of the generator by means of the pipe O.
Another branch S conducts air-to-an-opening or channel U above the passage V.
Another branch S₁ supplies air to the pipe F. R is a fire space-beneath-the
boiler wherein if needed, coal or gas may be burned. R¹ is a space for the escapo
of the products of combustion and R" a flue or outlet for them to the space T.
pin is a door giving access to the end of the regenerator B.
The method of operating this furnace is as follows:-A tire is kindled on the
grate, all the openings being shut, except P at the end of the regenerator and
the doors P and P" opening into the ash pit. When the furnace has become
somewhat warmed the depth of the fuel in I can be increased, all the openings to
the furnace are closed except X', air is driven in by the pipe S' through O to the
fire space between K K and the grate and passing through the coal goes over into.
the regenerator B in the form of hot gases. These passing through the loose
bricks therein deposit their sensible heat together with heavy vapors and atomic
carbon. A considerable percentage of combustible gas (CO) still remains
unconsumed and this is utilized by igniting it with a second blast of air sent into
the connecting pipe F by means of the pipe S. This causes combustion to ensue
in the pipe G which traversing the boiler beneath the surface of the water imparts
to the water its heat and the resulting gases now entirely non-combustible, passing
through G¹ into the space T rise thence through the tubes of D parting with their
sensible hent to the water surrounding them, and escape at a low temperature into
the open air.
When sufficient heat is attained in the furnace and sufficient steam generated in
the boiler, both blasts, viz: S' and Sin are shut off, sufficient steam is let in by Z
to expel the products of combustion remaining in the furnace an the boiler pipe G
and these non-combustible gases are thus prevented mixing with and diluting the
combustible gases subsequently made-X is then closed and the hydraulic
valve E is opened by being lifted. Steam is then let in through Z' into
G' and passing through G enters the regenerator B through F and passing
through the hot bricks becomes highly superheated and entering the generator

page_text: -
through the passage V comes in contact with the glowing coals; a mutual
decomposition of the carbon and steam occurs forming what is called
"water gas." This escapes from the base of the generator through the pipe O
into and through the hydraulic main into the pipe H" thence into the boiler by
means of H. Passing through this pipe H it imparts its heat to the water and
issuing from the boiler into the space T¹ rises upward through the tubes of the
water heater D¹ yielding most of its remaining heat to the water therein and
passing out of T through the pipe Q and valve Y at a low temperature goes to tho
holder or place of use. After a sufficient flow of gas has taken place the steam
at Z is shut off, the hydraulic valve E' is closed, the cover X' is removed from G¹,
sufficient steam is admitted at Z" to expel the combustible gas remaining in the
generator, coal is added if required at X, any necessary stoking is done through
the various doors and the process before mentioned is repeated-If it is desired in
making gas to utilize tars or other fluid, semi-fluid or granulated hydro-carbons
such materials can best be introduced at U by such devices as may be suited to the
peculiarities of the substance used. As these vary with the materials, no special
device is shown in the drawing. But as it is found that some of these materials
have a tendency to burn to a species of coke if used in the presence of superhoated
steam, in the opening U which thereby becomes obstructed, I therefore introduce
at the proper time air into this opening by means of the blast pipe S by which an
active combustion ensues and the opening is freed of the material clogging it. In
the drawing the opening U is shown as simply covered with a plate W which can
be removed to give place to any device adapted to the materials which it is
designed to inject at that point. A quite novel use may be made of such forms of
fuel when it desired to economize the fuel burned on the grate, as follows.
After the furnace has been sufficiently heated and is being worked with air blast,
the blast may be partly or entirely shut off at the pipe S so that little or no air
shall pass upward through the coal in I and the blast at S" being opened air is
driven in through U, and fluid, semi fluid or granulated fuel is simultaneously fed
into this opening U and mingling with the air burns actively in the regenerator B.
Any combustible gases or fuel materials passing out of the regenerator by way
of F are burned by the blast S as before described. But a considerable portion
of the fuel thus carried in remains unconverted or partially converted and being
distributed in a finely divided form among the crevices of the regenerator and at a
high temperature is in the most favorable condition for rapid decomposition with
the steam subsequently admitted. Any ash remaining can be cleaned out by blast or
otherwise through the door P¹¹. In the manufacture of water gas heretofore, fluid
or granulated fuel has been fed to the furnace only in connection with a blast of
superheated steam and never with air blast as just described. By combining these
two methods a continuous use of such economic forms of fuel may be secured.
The drawings represent two generators which render the operation of gas making
practically continuous, one furnace blowing with air, while the other blows with
steam, by which means the working of the boiler and the supply of steam are
regular and constant. The radiating heat from two sides of the regenerators acts
upon the boiler and if further heat is required in getting up or maintaining steain
it is obtained by either a coal or gas fire beneath the boiler at R. Of course a
single generator may be built upon the same general principle.
Having now described the nature of the said Invention as communicated to
me and in what manner the same is to be performed I declare that I claim :-
First. The combination of the gas generators A. A with the regenerator BB
boiler C and multitubular vessels D D for the purpose of alternately using the
one generator for the production of gas by air blast which gas after passing through
its regenerator chamber to heat the same is burned with air in order to raise steam
in C and to heat water in D while the other generator and its regenerator is used
as described for the production of gas by the decomposition of the steam which
gas (known as water gas) may be used for heating and other purposes; the

page_text: simultaneous working of the two generators constituting a continuous united
system, all substantially as described.
Second. The combination of the generator A. and regenerator B in a compound
furnace for the production of water gas continuously connected and separated
without the intervention of partition walls in such a manner that the currents of
air, steam or gas are compelled to follow the compound furnace in the desired
inanner, substantially as described,
Third. The furnace A with its combustion chamber I and its direct continuous
communication with the regenerator chainber B in combination with the arrange-
ment of the pipe O opening above the grate the channel or opening U with blast
pipe S opening into the passage V for the admission of fluid or granulated solid
fuel together with the blast air for the heating of the regenerator B and boiler C
substantially as described.
Fourth. The water vessel K K constructed of halves at the base of the com-
bustion chamber I which halves may be removed and introduced by means of the
removal plate L without dismantling the furnace, substantially as described.
Fifth. The clack valve E' in the hydraulic main E regulated from outside by
rods sliding through narrow pipes substantially as and for the purpose described.
Sixth. The arrangement of tubes H H and G G within the boiler with the lids
at their ends to allow of their being cleaned from the outside; the combination of
pipe G with the regenerator-B-by-means-of-the-pipe-F-and-of-pipe-H-with-
generator A by means of pipes O and H" and hydraulic main E, all substantially
as described.
Seventh. In the process of working the apparatus described for the production
of gas, the introduction of steam through pipe Z" into O for the expulsion of the
residual gases in the contrary direction prior to the admission of steam for the
generation of water gas substantially as described.
Eighth. The manufacture of water gas by the employment of apparatus
constructed and working substantially as herein before described.
In witness whereof I the said John Clayton Mewburn have hereunto set my
hand and seal this twentieth day of October One thousand eight hundred
and eighty two.