AN IMPROVED MEANS FOR THE PRODUCTION OF WATER GAS
Year: 1888

page_text: I, CARL WESTPHAL of Gartenstrasse, Berlin in the German Empire, Railway
Superintendent, do hereby declare the nature of said invention for "AN IMPROVED
MEANS FOR THE PRODUCTION OF WATER GAS" and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
The furnace employed for the production, in accordance with this invention, of
water gas, half from hydrogen half from carbonic oxide gas, generated from moist
fuel or combustible material, is shown in the accompanying drawing, Figs. 1 and 2
being respectively a sectional elevation and sectional plan thereof.
It consists of one or more vertical retorts heated with their contents according to
the contrary current principle by the gaseous products of combustion ascending in
serpentine flues from a fire of at first compact fuel and later of water gas combustible
when a sufficient quantity thereof has been generated, in such a way that these
products of combustion previous to escaping give up all their heat to the retorts,
the necessary addition of atmospheric air for effecting combustion being supplied at
the commencement by an air blast (not shown) and afterwards by the sufficiently
strong pressure of water gas combustible which draws through a number of
adjustable Bunsen burners the quantity of atmospheric air necessary for its combustion
in a reducing flame. This atmospheric air previous to entering the combustion space
at 3 passes first through the grate and glowing compact fuel then with the water gas
through a number of apertures in the side of flue stage 3. The grate is now put out
of action by stopping up with sand and filling in underneath it with clay, or instead
of this the grate may be shut off by means of a fire clay closure. The air and
water gas now pass into flue stages 1 and 2, the retorts with their still hot falling
contents of ashes being preliminarily heated thereby. As the number of flue stages
above and underneath 3 may be increased according to requirement the furnace is
provided at the bottom with a vertical intermediate bed of ashes or other suitable non
conductor of heat, the heat of the fire being utilised as much as possible for the
generation of water vapour in the retorts at the level of flue stages 3 and 4 as well
as for the preliminary heating of the material serving for this generation of vapour,
viz.; a mixture of pulverised brown coal or turf and water in the proportion by
weight of 1 part pure carbon (exclusive of ash and oxygen) to 3 parts water,

page_text: exclusive of the quantity corresponding to the oxygen in the coal, so that only water
gas and ash is produced without any residue of coal or water vapour. In this
proportion the mixture is sufficiently moist and the adhesion of the water to the
suitably granulated carbon particles by which the water is retained in the descent, is
great enough at a certain height of the bed of the mixture in the retorts, to prevent
the escape of vapours and gases upwards through the mixture even if by the action
of the heat a steam or gas pressure is created in the retorts corresponding to a water
column of 100 millimeters and upwards, as found in practice. The water gas formed
must therefore escape through pipes giving off heat around in a stream contrary
to that of the descending coal and water mixture, first into an intermediate
container of known construction, or direct into a gasometer, whence it may in small
part flow back direct into the combustion stages 3 whilst the remaining portion may
be dealt with as desired. The ashes remaining behind in the retorts are withdrawn
by moans of endless screws arranged at the bottom of the retorts so as to turn by
the effect of the weight of the coal and water column bearing upon them,-into a
vessel supplied with water and serving as ash pit, the removal may also be effected
by oblique or horizontal screws or elevators, and is facilitated by the enlarged taper
form of the retorts at the bottom by which the friction of the contents against the
inner surface of the same is diminished. The retorts dip into the water vessel
shutting themselves off at such a depth as corresponds to the gasometer pressure,
thus they are closed at bottom by ashes and above by coal to the gases and vapours.
The revolution of the endless screws is effected by mechanism regulated by weights.
By this motion a centrifugal governor is set in motion by gearing (not shown) and
regulates in a known manner the passage through cock or valve of the water gas
with its just sufficient quantity of atmospheric air for a reducing flame which will not
attack the material of which the retorts are composed, the most preferable for which
is a composition of cast iron and cast stecl. Fire clay or fire brick retorts do not
bear sufficiently well the unequal beating unless composed of separate rings each of
the height and temperature of a fluo stage and jointed with asbestos rings in recessed
socket like surfaces. Such coal material as does not yield slag or does so to a very
small extent is best for the production of the water gas, although rather large slags
may pass along the endless screws for removal.
By means of this apparatus, and process effected with the same, moist combustible
material may be converted into water gas, a result not hitherto attained.
Having now particularly described and ascertained the nature of my said
invention and in what mannor the same is to be performed I declare that what
I claim is :-
1. For the production of water gas in vertical retorts open at top and bottom the
use of natural moist or artificially moistened combustible material such as moist
brown coal and turf for charging the same and as upper closure therefor, the bottom
of the rotorts being shut off by a water closure, and the retorts being heated from
outside on the contrary current principle; so that the fire gases ascend worm like
whilst the combustible material inside the retorts descends continuously, the water gas.
produced being withdrawn from the retorts by internal pipes g projecting downwards
to the point of gasification, the heat from which pipes communicated to the same by
the escaping gas serves for the preliminary heating of the combustible material
surrounding them, substantially as described and shewn.
2. In combination with the said retorts the preliminary heating of the air for
combustion by passing round the lower part of the vertical retorts charged with ashes
before meeting the combustible gases through-passages 1 and 2 on the contrary current
principle substantially as described and shewn.
3. In combination with the said retorts the emptying or removal of ash from the
same by frictionally regulated endless screw mechanism arranged at the lower part of
the same, turned either by the effect of the weight of the retort contents or otherwise
substantially as described and shewn.
4, In combination with the said retorts, the governing of the supply of such

page_text: water gas as may be used for the outward heating of the retorts through the
discharging screws by means of a centrifugal governor and gearing and cock or
valve.
5. The taper enlargement of said retorts towards the bottom for the purpose of
facilitating the descent of their contents and the working of the endless screw discharge
mechanism, substantially as described and shewn.
6. The construction of said retorts of fire clay rings each of the same height as a
flue or fire stage and the jointing of the several rings in socket like surfaces by
asbostos rings substantially as described and shown.
7. By means of the said retort rings oach of the height of a flue or fire stage,
whether taper or parallel in form, the construction of the horizontal stage partitions
by comparatively thin fire brick plates or tiles, each with a central orifice of the
dinmoter of the outer diameter of the retort at the respective parts, by which the
plate is held in its position while it rests upon the upper edge of the ring socket
immediately underneath, substantially as described and shewn.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C.,
Agents for the Applicant.