IMPROVEMENTS IN FURNACES FOR USE IN THE MANUFACTURE OF GAS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I WILLIAM PHILLIPS THOMPSON, Fel. Inst. P.A., of the Agency for Foreign
Patent Solicitors, 6 Lord Street Liverpool, in the County of Lancaster, and
323 High Holborn in the County of Middlesex, Civil Engineer do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN FURNACES FOR USE IN
THE MANUFACTURE OF GAS" and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
The improvements are particularly applicable to retort furnaces for the
manufacture of gas (Fig. 1-7), and consist firstly of the arrangement of the
channels of the regenerator grouped on the right and left in such a manner that
the middle part of the furnace suffering especially from the heat of the heating
gases entering the furnace will receive a strong foundation; another improvement is
that the mixture of the carbonic oxide with the heated air is effected only in the
upper part of the furnace, so that the lower part of the furnace or the lower
retorts will receive correspondingly less heat, and are thus prevented from being
injured, which would otherwise occur very soon.
As the mixture of the carbonic oxide with the heated air will take place only in
the upper part of the furnace, the development of heat will go on only gradually;
the beating gases retain in consequence heat in a sufficient quantity for giving
even the last retorts on each side the necessary temperature, whereby uniform high
temperature will be obtained for all the retorts.
A further improvement of the furnace consists in this, that the production of
steam for the generator (Sheet 1 Fig. 2, and Sheets 2 and 3, Figs. 8 to 14) is
effected in closed iron evaporating vessels, arranged in the lower part of the
regenerator on the right and left in the space between the flues of the products
of combustion escaping to the chimney flue.
The application of steam for the generator produced by the escaping smoked
gases, that is by combustible gases, is not new, but hitherto the steam has been
produced by placing a water vessel open at the top directly underneath the grate
of the generator and by conducting a chimney flue under this vessel.
.
This arrangement requires the flues for the smoke gases respectively for the
combustible gases of the furnace to be sunk very much below the furnace, whereby
not only will the accessibility be rendered difficult, but also the draught will be
influenced, and the working of the furnace will even be interrupted whenever the
single evaporating vessel is injured, moreover the great depth at which this
arrangement has to be constructed entails considerable extra expense.
By the improvements of this Invention the above described drawbacks have
been avoided, as the evaporating vessels made of wrought iron and protected by an

page_text: intervening layer of fire bricks, are not liable to be injured; should this however
occur to any apparatus, the second vessel would produce a quantity of steam
sufficient for keeping the furnace in regular operation. The arrangement has been
designed in such a manner that the vessels may be taken out quickly and easily,
and exchanged for new ones, so that, if necessary this alteration may be effected
within an hour.
Another improvement consists of the heating in the space between the double
walls of the generator of the fresh air, entering beneath the grate of the generator,
whereby the heat of the walls of the generator, otherwise lost by radiation, may be
recovered and utilized.
An improvement will also be found in the circumstance, that the steam in the
lower part of the generator entering beneath the grate of the latter on the right
and left through long nozzles is mixed with the fresh air which has just been
heated (Sheet 1 Fig. 2), escaping through several openings immediately above the
steam nozzle, in such way, that an equalisation of temperature of the two products
will take place, which equalisation is necessary for a thorough and uniform
combustion of the residues of combustion over the whole of the grate. An
improvement consists further of the arrangement by which a division a projects
above the grate of the generator on the back part of the latter towards the
heating chamber, by means of which air and steam are prevented from passing
uselessly and even injuriously through the space between the fuel and the wall
of the generator next to the heating chamber.
The construction of the furnace with the generator and the above mentioned
improvements is shown in the Sheet 1 (Fig. 1-7) of the annexed Drawings.
The fuel is introduced into the generator through its upper opening after
removing the spherically turned cover serving for closing, so that the whole space
may be filled up to the cover with fuel.
The generator is closed at its lower part by an air tight door which is opened
only when necessary for the purpose of removing the residues of combustion.
All the fresh air necessary for combustion as well as for production of carbonic
oxide gas must enter the generator through the openings f arranged sidewards
under the grate at the right and left, whereby this air is immediately mixed with
the steam escaping from the steam nozzles under the air openings.
At the bottom of the generator is a flat iron vessel (Fig. 5) for receiving water
in order to extinguish the residues of combustion falling through the grate. The
carbonic oxide gas formed in the generator and containing a considerable proportion
of hydrogen, passes through the flue o into the lower middle part of the furnace,
and thence in the direction of the arrows at the right and left into the free space n
between the retorts.
In exactly determined distances beneath these outlet openings are arranged the
inlet openings v (Fig. 5-7) for the heated air, whereby the mixture of carbonic
oxide gas with air as well as the conversion of these gases into carbonic acid gas
will take place only in the upper part, and gradually.
The heating gases take now their. ordinary way around the retorts to the
channels a (Fig. 1) arranged beneath the lowest side retorts, thence into the
flues cek and i and from the latter flue into the chimney flue (Fig. 6) placed
behind the furnaces..
.
Between the above mentioned flues for the smoke gases, that is, for the waste
heat of the furnace, are placed the flues for the heated air to which a considerable
portion of the heat is given off.
The heated air enters first into the lowest flues (Fig. 6) takes hence its way
through the flues m h g d and b and enters from the latter into the furnace beneath
the inlet of the carbonic oxide gas.
By the passage between the fire flues the temperature of the air is brought to a
very high degree, and the heat of the smoke gases otherwise lost, is in that way
vered for the fumess

page_text: Besides the air channels a closed iron vessel ƒ (Figs. 1, 6 and 7) is placed between
the flues at the right and left on each side, in which by means of a special
regulating apparatus the water level will be maintained at a constant level: The
steam formed in the vessels is conducted into the generator by means of a pipe
adapted to the front of the cover and provided with an envelope for retaining the
heat. The number of the retorts which may be placed in the furnace, is of course
optional.
The apparatus for evaporating water (Sheet II Fig. 8-11) consists of a square
or otherwise shaped vessel, made of boiler plate.
This vessel is completely closed at the sides and bottom, while the front opening
is closed by a cast-iron cover 7 (Figs. 8-11). Through this cover passes a water
inlet-pipe m which is placed so high externally that the water in the vessel cannot
be ejected by the steam produced therein. A second pipe n serves for exhausting
the steam and conducting it to the generator of the furnace.
A box p closed at the bottom and open at the top placed inside of the cover f
goes down till close to the bottom and is in communication with the exhaust pipe n
which conducts the generated steam to the pipe n without being cooled to the
temperature of the latter.
Near this box is another short box q closed at the top and open only at the
bottom. It serves first for allowing the water to run off through the over flow
pipe whenever the water in the vessel rises too high, and further for letting off
the steam as soon as the water level sinks to the lower edge of the box q, so that
an overheating of the steam in consequence of a too low water-level will be avoided.
The steam then escapes at r¹ through the piper open at the top and gives. hereby
notice to the fireman that the water is deficient.
A gauge glass in front of the cover shows the water-level in the vessel.
The above described special arrangements are designed to prevent there being
too much water or not water enough in the apparatus, and further to give sufficient
security against a sudden expansion of steam.
One of these evaporating vessels is placed at each side of the regenerator of the
furnace in its lowest part, so that the cover of the vessel is level with the front
wall of the furnace, and that the last, that is, the lowest fire flue of the generator
passes beneath it, before it enters into the chimney flue, giving hereby a portion of
the heat of the smoke gases over to the vessel, whereby these smoke gases are
partly utilised in the furnace.
In the above described apparatus, the supply of water is regulated by means of
a cock.
Another special apparatus (Sheet III Figs. 12-14) serves for regulating
automatically the water supply exactly according to the evaporation. This
apparatus consists of an iron vessel & (Fig. 13) connected at its bottom by a pipe
with the water inlet pipe m of the evaporating vessel. In the vessel 8 is a floating
box void of air and made of tin plate, mounting or descending according to the
water level of the evaporating vessel. Through this floating box, which is
provided at its upper end with a nut, passes a threaded rod t (Fig. 13.) in
adjustable connection with the said box, and carrying on its upper end a conical
valve of india-rubber u. Above the latter is a tube in connection with a cistern
or with the water pipe, the valve u bears against the orifice of this tube v and
closes it tightly as long as the steam in the evaporating vessel is at its normal
level. As soon as the water level descends, the floating box will descend too, and
in consequence the conical valve be opened, so that the evaporated water will
immediately be replaced.
Having now particularly described and ascertained the nature of the said
Invention, as communicated to me, and in what manner the same is to be.
performed, I declare that what I claim is :-
1st. The arrangement of all the fire and air flues of the regenerator disposed in
series one over the other at the right and left beneath the furnace, in such a

page_text: manner, that the middle foundation of the furnace will not be touched by them,
(Fig. 1 to 7).
2nd. The disposition of the inlets for the carbonic oxide gas and the heated air
in exactly determined distances one over another, in such way that the mixture of
these two gases and the transformation of them into carbonic acid gas, that is to
say, the production of the highest heat takes place gradually in passing through the
furnace between the retorts, whereby the retorts will be heated in a uniform
manner and particularly the heat be drawn off from the middle retorts, which are
most exposed, so that these retorts will be prevented from being injured in a
short time.
3rd. The arrangement of a closed iron evaporating vessel on both sides of the
regenerator beneath the fire place between the flues for the escaping smoke-gases.
(Fig. 1-7).
4th. The arrangement of an evaporating vessel in such a manner, that the
removal or exchange thereof may be rapidly and easily effected without interrupting
the working of the apparatus by simply unscrewing the steam-pipe leading from
the front cover to the generator. (Fig. 6 and 7).
5th. The heating of the fresh air entering the generator between the double
walls of the generator by receiving the radiated heat from the walls of the
generator.
6th. The arrangement of the outlet for steam and heated air on the two inner
sides of the generator beneath the grate, in such way that an intimate mixture of
the two products and an equalisation of temperature will take place (Figs. 2 & 5).
7th. The arrangement of a division in the generator above the grate, and on the
side of the generator towards the fire place, in order to avoid not only a useless,
but even injurious, circulation of air and steam through the space between the wall
of the generator and the fuel.
8th. The production of steam for generator purposes by means of 'one or several
iron vessels placed between the flues of the retort furnaces or generators, serving
for drawing off the smoke gases and for utilizing the heat of the smoke-gases
escaping from the furnace to the chimney flue.
9th. The combination of a steam escape pipe within the evaporating vessel.
10th. The arrangement of a channel in the evaporating vessel for the purpose of
regulating the water level and of indicating simultaneously a want of water by the
escape of the steam through a blast pipe arranged for this purpose, whereby over
heating and expansion of the steam is avoided.
11th. A regulating apparatus for the purpose of maintaining the water level of
evaporating vessels at the same height consisting of a floating box provided with a
conical valve descending and mounting according to the water level in the
evaporating vessel, whereby an opening and closing of the conical valve will be
effected, so that water may be introduced as required (Fig. 13).
12th. An arrangement for adjusting the floating box by means of a nut placed in
the upper end, whereby the threaded rod of the box is adjusted and the floating
apparatus thus placed exactly at the requisite height (Fig. 13).
Dated this 11th dov of Tul 1991
W. P. THOMPSON & Co.,
Per J. Q. O'Brien,
Of 6, Lord Street, Liverpool,
Agents for the Applicant.