IMPROVEMENTS IN OR CONNECTED WITH GAS GENERATORS
Year: 1879

page_text: LETTERS PATENT to Alfred Longsdon, of Queen Victioria Street, in the City
of London, for the Invention of "IMPROVEMENTS IN OR CONNECTED WITH
GAS GENERATORS." A communication from abroad by Alfred Krupp, of
Essen, in the Empire of Germany, Cast Steel Manufacturer.
Sealed the 2nd December 1879, and dated the 26th June 1879.
PROVISIONAL SPECIFICATION left by the said Alfred Longsdon at the Office
of the Commissioners of Patents on the 26th June 1879.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London.
" IM-
PROVEMENTS IN OR CONNECTED WITH GAS GENERATORS." (A communication
from abroad by Alfred Krupp, of Essen, in the Empire of Germany, Cast Steel
Manufacturer.)
Gas generators inade according to this Invention have a combustion or gas
producing space, and a preheating or distilling space, both parts forming together
one connected space.
The generator or retort is arranged as usual with grate or grating for admission
of the necessary air for combustion, and for the admission of water vapour.
The preheating or distilling space is produced by arranging in the upper part of
the whole generator space thin plates or tubes, by preference of sheet iron or steel,
so as to divide this upper space into partition spaces, one part of which serves to
receive the fuel, and the other for the passage of the produced gases before letting
them out. The fuel spaces are open above, but the gas spaces are closed. By these
means the fuel is prepared and utilized for gas production in a far more complete
manner than in gas generators as heretofore usually constructed.
The fuel is charged into the open spaces which I call preheaters and takes up the
whole space of this as well as the gas producing chambers. It thus forms a
continuous pile of fuel from the charging opening down to the air inlet. The hot
gases produced in the combustion space by the meeting of the introduced air, the
water vapour, and the incandescent coals pass along the walls of the preheater, and
then escape by a pipe. The fuel is so charged that the preheater is always kept
filled.
The fuel descends slowly in proportion as it is consumed in the gas producing or
combustion chamber, and in a well prepared preheater dried and partly distilled
state (by the influence of hot gases passing along the walls), passes towards the air

page_text: inlet to the fireplace. The products of distillation enter by the preheaters, which
are open below, into the common gas space, and together with the directly produced
generator gases escape into the gas outlet.
The water contained in the fuel evaporates in the upper part of the preheater
and escapes by the open charging aperture. The height of the fuel pile in the
preheater prevents the escape upwards of the gases produced in the generator, and
allows on the one hand the products of distillation to go out below, and on the
other hand the water vapours to go out above. In this manner loss of gas by the
charging of fuel is very efficiently prevented.
The plates do not burn away, as the gradually descending fuel keeps them
sufficiently cool.
The arrangement of the preheaters in the upper part of the generator may vary
according to their form and number, and also according to their manner of 6xing.
Their form and number depend mainly on the character of the fuel and on local
circumstances. The fixing may be so that the thin walled preheaters are attached
to the top covering plate of the generator, or they may in some way be firmly
connected to the brick walls of the generator. The mode of leading off the gases
may vary, and is modified according to the preheater and its walls; it may be done
by one outlet or by several, and it may be through the walls of the generator and
of the preheater as well as through the upper cover of the generator.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Longsdon in the Great Seal Patent Office on the 23rd December
1879.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London.
" IM-
PROVEMENTS IN OR CONNECTED WITH GAS GENERATORS." (A communication
from abroad by Alfred Krupp, of Essen, in the Empire of Germany, Cast Steel
Manufacturer.)
Gas generators made according to this Invention have a combustion or gas
producing space and a preheating or distilling space, both parts forming together
one connected space.
The generator or retort is arranged as usual with grate or grating for admission
of the necessary air for combustion and for the admission of water vapour.
The preheating or distilling space is produced by arranging in the upper part of
the whole generator space thin plates or tubes, by preference of sheet iron or steel,
so as to divide this upper space into partition spaces, one part of which serves to
receive the fuel, and tho other for the passage of the produced gases before passing
to the supply tubes or canals. The fuel spaces are open above, but the gas spaces
are closed. By these means the fuel is prepared and utilized for gas production
in a far more complete manner than in gas generators as heretofore usually
constructed.
The fuel is charged into the open spaces which I call preheaters, and takes up
the whole space of this as well as the gas producing chambers; it thus forms a
continuous pile of fuel from the charging opening down to the air inlet. The hot
gases produced in the combustion space by the meeting of the introduced air, the
water vapour, and the incandescent coals pass along the walls of the preheater, and
then escape by a pipe. The fuel is so charged that the preheater is always kept
filled.
The fuel descends slowly in proportion as it is consumed in the gas producing or
combustion chamber, and in a well prepared, preheated, dried, and partly distilled
state (by the influence of the hot gases passing along the walls), passes towards tho
air inlet to the fire place. The products of distillation enter by the preheaters,
which are open below, into the common gas space, and together with the directly
produced generator gases escape into the gas outlet.
The water contained in the fuel evaporates in the upper part of the preheater.
and escapes by the open charging aperture. The height of the fuel pile in the
preheater prevents the escape upwards of the gases produced in the generator, and
allows on the one hand the products of distillation to go out below, and on the
other band the water vapours to go out above. In this manner loss of gas by the
charging of fuel is very efficiently prevented.
The plates do not burn away, as the gradually descending fuel keeps them
sufficiently cool.
The arrangement of the preheaters in the upper part of the generator may vary
according to their form and number, and also according to their manner of fixing.
Their form and number depend mainly on the character of the fuel and on local
circumstances. The fixing may be so that the thin walled preheaters are attached
to the top covering plate of the generator, or they may in some way be firmly
connected to the brick walls of the generator.
The mode of leading off the gases may vary, and is modified according to the
preheater and its walls; it may be done by one outlet or by several, and it may be
through the walls of the generator and of the preheater as well as through the
upper cover of the generator.
And in order that this Invention may be moro fully understood I will now
proceed to describe the same with reference to tho accompanying Drawings,

page_text: Figure 1 shows a generator with one double walled retort, and Figure 1ª a
generator with two double walled retorts. The outer circumference or wall a is
open at top and bottom, while the inner wall b is closed at top by a lid. There are
passages e forming communication between the inner gas space d and the outer gas
space e' of the generator. The space between the wall a and the wall b serves for
the reception of the fuel, and thus the core or interior part of the mass of this
fuel is heated, and not the outer part or crust only as in arrangements heretofore
known.
Figure 2 represents a generator with a single ring retort of such an inner
diameter as to leave a comparatively narrow ring space for the fuel therein which
is thus exposed to thorough heating by the gas which ascends through the middle
part d.
Figure 3 shows the reverse arrangement to that shown in Figures 1 and 14, the
ring shaped space formed by the wall a and the wall b of the retort in this case
forming the gas outlet, the space within the inner wall b and around the outer
wall a forming the fuel space.
In Figures 4 to 13 I have shown a variety of plan sections of generators with
annular fuel spaces these arrangements may be still further varied by alterations
in the form and number of the retorts, and the form of the generator in which they
are placed.
In all cases, and because of the annular fuel space arrangement and the consequent
subdivision of the bulk of the fuel, an increased heating surface, the fuel is heated
more intensely and equally than by the arrangements heretofore usual; the drying,
preheating, and degasification of the fuel descending in the ring spaces proceeds in
such a measure that the masses of dead, conical, pyramidal, or wedge formed masses
of fuel, moving down under the retorts of the usual construction, are unknown with
these ring shaped spaces; on the contrary, the fuel after it comes out of the ring
spaces or ring retorts possesses the looseness required for a plentiful and uniform
gas production. By these improvements, and because of the aforesaid properties,
these gases are prevented from striking through along the walls of the generator by
passages there formed through the fuel, and which are not favourable to the
diminution of formation of carbonic acid, but rather favour same.
The advantages gained as against the ordinary generators are, first, a more
plentiful gas production by constant quality of same; second, gases of better quality,
high percentage of carbonic oxide, and by admission of water vapour in the gas
producing space also high percentage of hydrogen; third, the use of fossil fuel of
any sort, especially of the fine grained kinds.
And having thus described and ascertained the nature of this Invention, and
in what manner the same is or may be carried into effect, I declare that I
claim,―
The subdivision of the fuel in gas generators into spaces or chambers having
surrounding or intervening gas spaces, substantially as and for the purposes herein-
before described, and shown in the accompanying Drawings.
In witness whereof, I, the said Alfred Longsdon, have hereunto set my hand
and seal, this Fourteenth day of November, in the year of our Lord One
thousand eight hundred and seventy nine.