Improved Means of Utilising Waste Gases in Regenerative Gas Furnaces.
Year: 1890

page_text: Date of Application, 11th Oct., 1890
Complete Specification Left, 8th July, 1891-Accepted, 8th Aug., 1891
PROVISIONAL SPECIFICATION.
Improved Means of Utilising Waste Gases in Regenerative Gas
Furnaces.
I, FREDERICK SIEMENS, of 10 Queen Anne's Gate, Westminster in the County
of Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:-
In the Specification No. 15,127 of 1884 were described means of utilising waste
gaseous products of combustion in regenerative gas furnaces, by causing a portion
of those gases after doing work in the furnace to pass through hot fuel, so that the
carbonic anhydride of the gases might become converted into carbonic oxide fit for
being burned again.
Also, in the Specifications No. 4644 of 1889 and No. 20,083 of 1889 were
described constructions of furnaces having air regenerators only, and having gas
producers placed near the furnace chamber and supplied in part with waste gases
from the furnace chamber or with heated air from the regenerator.
The present invention applies to regenerative gas furnaces provided with air
regenerators alone, or with gas as well as air regenerators either reversible or
continuous. In the former case, the gaseous products of combustion from the
furnace that are to be introduced into the gas producers may be taken from the
chimney flue, or from the upper part of the air regenerators, or from any place
between these points; in the latter case, the gaseous products of combustion from
the furnace, that are to be introduced into the gas producers, may be taken from
the chimney flue or from either or both of the gas and air regenerators, or from any
point between the furnace chainber and the chimney flue.
The gas producers of such furnaces are placed near them, and are supplied by
the action of steam, air or other injector jets, with the gaseous products of com-
bustion above referred to, the passages to the producers being so arranged in
relation to the flues and reversing valves, when such valves are employed, that gas
or air leaking past them are carried into the producers. The waste gases from
furnaces introduced into gas producers may be mixed with air at their entrance
into them; or air, heated or not, may be introduced into the gas producers by
separate jets or blowers.
Dated this 11th dov of October 1890.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Means of Utilising Waste Gases in Regenerative Gas
Furnaces.
1, FREDERICK SIEMENS, of 10 Queen Anne's Gate, Westminster, London, S.W.
Civil Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
In the Specification No. 15,127 of 1884 were described means of utilising waste
gaseous products of combustion in regenerative gas furnaces, by causing a portion
of those gases, after doing work in the furnace, to pass through hot fuel, so that the
carbonic anhydride of the gases might become converted into carbonic oxide fit for
being burned again.

page_text: described constructions of furnaces having air regenerators only, and having gas
producers placed near the furnace chambers and supplied in part with waste gases
from the furnace chambers or with heated air from the regenerators.
The present invention applies to regenerative gas furnaces provided with air
regenerators alone, or with gas as well as air regenerators, these being in both
cases either reversible or continuous. In the former case, the gaseous products of
combustion from the furnace, that are to be introduced into the gas producers, may
be taken from the chimney flue, or from the upper part of the air regenerators, or
from any place between these points; in the latter case, the gaseous products of
combustion from the furnaces that are to be introduced into the gas producers, may
be taken from the chimney flue, or from either or both of the gas and air
regenerators, or from any point between the furnace chamber and the chimney
flue.
The gas producers of such furnaces are placed near them, and are supplied by
the action of steam, air, or other injector jets, with the gaseous products of com-
bustion above referred to, the passages to the producers being so arranged in
relation to the flues and reversing valves, when such valves are employed, that gas
or air leaking past them are carried into the producers. The waste gases from
furnaces introduced into gas producers may be mixed with air at their entrance
into them or air, heated or not, may be introduced into the gas producers by
separate jets or blowers.
Figure of the accompanying drawings is a vertical section of a regenerative
gas furnace with gas producer arranged according to this invention the section being
taken on the line Y Y of Figure 2 which is a sectional plan on the line X X of
Figure 1.
A is the furnace chamber which may be of considerable length extending over
the gas regenerators B B and the air regenerators B B¹ through a pair of which
the hot products of combustion pass from the furnace on their way to the chimney
flue G while the air and gas pass through the other pair on their way to the furnace,
the action of the two pairs of regenerators being alternated in the usual way by
means of reversing valves W and W2. The air and gas enter the furnace chainber
by ports F D, at its one end, the products of combustion issuing by corresponding
ports at its other end. C is the producer provided with poking and ash doors M M
and with a steam, compressed air or oxygen jet for introducing more or less air
to the ash pit as may be required to maintain the necessary heat. In connection
with the passage to the chimney flue G2 (which is governed by the damper N) is
formed a passage H into the ash pit of the producer, and in this is arranged a
jet K of steam, air or oxygen, by the action of which some of the products of
combustion are drawn from the flue G and driven into the producer, together with
such gas and air as may be mixed with them owing to leakage through the reversing
valves W W or otherwise. The supply to the jet K may be shut off and, the
passage H being closed by the valve U, the producer can be worked without being
supplied with products of combustion, either by means of the jet J or by removing
the doors M M'.
Figure 3 is a sectional plan of the regenerators of a furnace and a producer, and
the latter in this arrangement is shewn to receive supply of products of combustion
from either of the air regenerators B' by passages S or S. Passages might be
formed from the gas regenerators B B to the producer C or to the flues S S' (as
shewn in dotted lines at T T) so that the producer might receive a portion of the
products of combustion either from the air regenerators or from the gas regenerators,
or from both.
Figure 4 is a longitudinal section showing an arrangement of furnace having the
air regenerators B' below, as shewn in Figure 1 of the drawings annexed to my
former Specification No. 4644 of 1889, but having a pair of alternating gas
regenerators (of which one B B is shown) interposed between the producer Č and
the furnace chamber A. Each of these gas regenerators consists of two compart-
ments BB separated, except at the lower part, by a partition X, causing the gases

page_text: to descend the one and ascend the other, but this arrangement may be varied by
constructing suitable gas regenerators without such partition walls as X. The gas
regenerators are connected to the chimney flue G2 by flues governed by valves R.
to the top of the producer C by flues governed by valves V, and to the ash pit
of the gas producer by passages H provided with jets K and valves U. It will be
understood that a portion of the gas which may leak through the valve V
Figure 4 will be carried into the gas producer with the products of combustion by
the action of the jets K. Figure 9 shews a construction of furnace in which the
lower part of the gas producer is at about the same level as the upper part or roof
of the furnace chamber A., with the object of obtaining a pressure of the products
of combustion at the point where they are injected into the gas producer, so as to
facilitate their injection into it. In this form of furnace, gas as well as air
regenerators might be adopted. The gas producer C is shewn with a solid hearth
(instead of a grate) which may be used with advantage in some cases.
In the figures above referred to the regenerators shewn are of the reversible type
but it will be understood that instead of reversible, continuously acting regenerators
may be used for heating both gas and air.
Figure 5 is a part longitudinal section on the line X X of Figure 6 which is a
sectional plan on the line Y Y of Figure 5, and Figure 7 is a transverse section on
the line % of Figure 5 of a furnace with continuously acting air regenerators
arranged on each side of a central producer C. The products of combustion from
the furnace chamber A, which in this case is shewn as applied for heating gas
retorts R, pass along the zigzag flues P P² p³ p towards the chimney flue G,
while the air supply becomes heated by passing along the adjacent zigzag
flues W W W W and is delivered by suitable openings, not shewn, into the
combustion flues D¹ D' where it enters into combustion with gas issuing from the
gas producer C through the ports D D. From the lower flues P on cach side,
passages H lead into the producer C, these passages being provided with jets K.
In these drawings, the air regenerator is shewn divided into two parts, but it will
be understood that, in many cases, it may be preferable to employ one air
regenerator as shewn in Figs. 4 and 5 of my Patent Specification No. 20,083
of 1889, or that air regenerators of the reversible type may be employed as shewn
in Figs. 1, 2, 3, 4 and 9 of this Specification in Figs. 1 and 2 of the Specification
No. 20,083 of 1889 and again in Figs. 1, 3, 6, 8, 9, 11, 13, 14 of the Specification
No. 4644 of 1889. In Figs. 5, 6 and 7 the products of combustion are shewn as
delivered into the gas producer through two openings from the bottom of the air
regenerator, and in Figs. 1 and 2 they are shewn as delivered into the gas producer
from one opening near the chimney fluc, and in Fig. 3 they are shewn as delivered
into the producer from the top part of the gas and air regenerators, and in Fig. 4
they are shewn as delivered into the gas producer from the bottom of the gas
regenerator.
But it will be understood that when air regenerators alone are used the products
of combustion may be taken from any other place between the top of the
regenerator and the chimney flue, and that, when gas and air regenerators are used,
the products of combustion may be taken from any point between the furnace
chamber and the chimney flue and in both cases they may be delivered into the gas
producers through any number of openings, as may be required; whether reversible
or continuously acting regenerators are employed.
Although in Figs. 6 and 7 of the annexed drawings also in Figs. 4 and 5 of the
drawings of my Patent Specification No. 20,083 of 1889, regenerators of zigzag
form are shewn, it is to be understood that I do not limit myself to the use of this
form of continuously acting regenerator, either in furnaces provided with air
regenerators alone, or in furnaces provided with gas and air regenerators, as another
form of regenerator, or the zigzag form of regenerator combined with another form
might be used.
Fig. 8 is a sectional plan of a furnace and gas producer with reversible air

page_text: regenerators arranged so that the flame enters the heating chamber A continuously
from two flame ports B1 B2. the products of combustion passing away continuously
through one opening C. As shewn in the drawing, air issuing from one of the
regenerators by the opening D' flows to the ports B1 and B2 where it meets with
gas issuing from the producer E through the passages B3 B, and the products of
combustion pass through the flue C, to a cross flue C, and are partly directed
under the gas producer E, and partly by the flue F, through one of the
regenerators, and the reversing valve G to the chimney. The direction of
the gaseous currents is indicated by arrows. To reverse the action of the
regenerators, D and should be closed, and D2 and 2 opened by shifting the
sliding dampers in connection with them, and by throwing over the reversing
valve G. Instead of only two flame ports Band B, several may be made, and,
instead of making the outlets for the products of combustion near the middle of the
furnace, the inlet or inlets might be placed there, and the outlets placed near the
ends of the furnace.
The flame ports of furnaces built in accordance with this invention may differ
in construction from those shewn by the annexed drawings, their special con-
struction or arrangement forming no part of this present invention. Although,
in all the furnaces described, it is indicated that products of combustion may
be imroduced into the gas producers, air heated or not may also be introduced
in conjunction with them or otherwise, as set forth in my previous Specification
No. 20,083 of 1889.
Fig. 10 shows a form of gas producer which may be used in furnaces constructed
for regenerating the products of combustion. In this construction, the fuel is
charged through a vertical retort A projecting into the producer chamber Bin
which the fuel is distilled, the issuing gases passing to the chamber C, whence they
are injected with the products of combustion coming from the furnace through the
flue D into the gas producer by means of the injector E. These distilled gases, by
mixture with the highly heated products of combustion, will be transformed into
permanent gases of light specific gravity, and this action will be promoted by
their passage through the incandescent fuel, in company with the other gases
to be converted, whence all the gases pass away through the flue G to the furnace
chamber.
By admitting air or oxygen through the flue F, the combustible gases may be
ignited below the producer grate, and thus help to maintain the heat of the
incandescent fuel, or they may be ignited in the chamber C, by means of air or
oxygen introduced through the pipe H, or otherwise, and mixed in the burnt
condition with the products of combustion coming from the furnace by the flue D
and be drawn into the gas producer by the injector E.
In the Specification of the Patent No. 972 of 1863 granted to my brother, the
late Sir William Siemens and myself conjointly, means were described whereby
the hydro-carbon gases liberated from fuel under decomposition in vertical gas
producers supplied with air by steam injectors could be withdrawn at the top of
the chamber to be dealt with separately from the other gases produced or to be
mixed with them, or these gases could be passed through the incandescent fuel in
the lower part of the apparatus, in order to decompose the heavy hydro-carbon
gases and vapours evolved. Also in the Specifications of Patents Nos. 3018
of 1864, 1513 of 1870, 3374 of 1880, 3792 of 1881, and 663 of 1883 obtained by the
said Sir W. Siemens various means were shewn whereby hydro-carbon gases
liberated from fuel under decomposition in gas producers could be passed through
incandescent fuel in the same producers, for the purpose of converting them into
permanent gases, so as to avoid deposit of tar in flues. Again in the Specification
No. 9103 of 1884 of an invention communicated by myself, several forms of gas
producers were shown and described with means of dealing separately with the
hydro-carbon gases evolved from the upper part of fuel under decomposition, or of
mixing them with the other gases produced, in both cases after the hydrocarbons

page_text: had been intensely heated by passage through heated channels, or by being brought
into contact with incandescent fuel for the purpose of converting tarry constituents
into permanent gases.
All the Specifications above referred to relate to the conversion of heavy hydro-
carbons into permanent gases by passing them, without admixture, through, or in
contact with, incandescent fuel in gas pro lucers, or through channels heated by such
incandescent fuel; whereas the arrangement shewn in Fig. 10 involves the intro-
duction into gas producers of the hydrocarbons mixed with hot products of
combustion, which hydrocarbons may be ignited and burnt below the grate of the
producer, or may be burnt in a separate chamber previous to their introduction into
the gas producer.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a regenerative gas furnace provided with both gas and air regenerators of
the reversible or continuously acting types, means whereby a portion of the products
of combustion may be injected into the gas producer from any part of their course
to the chimney flue, with, or without, a portion of such gas, or air, or both, as may
leak through imperfect appliances, substantially as described.
2. In a regenerative gas furnace provided only with air regenerators of the
reversible or continuously acting types means whereby a portion of the products of
combustion may be injected into the gas producer from the upper part of the
regenerators, or from any part of their course thence to the chimney ilue, substantially
as described.
Dated this 3rd day of July 1891
ABEL & IMRAY,
Agents for the Applicant.