Year: 1895

page_text: Date of Application, 31st May, 1895-Accepted, 29th Feb., 1896
I, JOHN GJERS, of Ayresome Iron Works, Middlesborough-on-Tees, in the
County of York, Ironmaster, 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 of Letters Patent No. 2720 of 1894 granted to me, I have
described furnaces in which the fuel is contained in a close combustion chamber
having a solid bottom, and is supplied with hot air for surface combustion through
an air inlet or passage that is in communication with an air heater, the arrange-
ment being such that hot air is caused to impinge upon the surface of the fuel and
the resulting flame and hot gases then pass into the chamber or place where the
heat thereof is to be utilized.
Now this present invention has reference to improved apparatus for generating
steam in which I combine and suitably arrange together a vessel or vessels (herein-
after called the steam generating vessel or vessels) for containing water and
wherein steam can be generated from such water and a furnace or furnaces
designed to operate on the surface combustion principle already referred to
(or modified according to my other application for Patent of even date herewith
No. 10815) with means for imparting to the air that is to be used to support
combustion heat from the hot gases passing away after the products of combustion
have been used for imparting heat to the heating surfaces of the steam generating
vessel or vessels.
Referring to the accompanying illustrative drawings
Fig. 1 is a vertical section on the line A B of Fig. 2; Fig. 2 a sectional plan,
partly on the line C D and partly on the line EF of Fig. 1; and Fig. 3 an
end elevation, partly in cross section on the line G H of Fig. 1 showing one
arrangement of steam generating apparatus, according to this invention.
1, 1 are two steam generating vessels of the multitubular type, arranged
horizontally side by side at a suitable distance apart, and preferably connected at
top and bottom by large transverse steam and water tubes 2 and 3 respectively, so
that the same steam pressure and water level shall obtain in the two vessels. At
the front end of each steam generating vessel is a combustion chamber 4 having a
solid hearth 5 for coal or like fuel 6. It is formed in refractory material 7, and is
provided with openings 8 for introduction of solid fuel, and openings 9 for removal
of ashes, these openings being normally closed by close fitting doors 8" and "
respectively. At the rear ends of the steam generating vessels is a flue 10 common
to and connecting the flue spaces of the two vessels. The rear wall of this flue
is formed partly by plates 10ª in which are holes 10' that are normally closed, but
through which a suitable tool can be introduced when necessary for cleaning the
tubes 1 of the steam generating vessels. The plates 10%, as well as the tube
plates are protected from direct contact with flame and hot gases by refractory
material as shown.
Above each combustion chamber 4 is a regenerator 11 that may be of any
suitable kind. That shown, which is similar to those shown in my said former
Specification, consists of a vertical cylinder with cellular firebrick filling 11"
through which can flow hot gases in the direction of the arrows shown in Fig. 3,
and afterwards air in the direction of the arrows shown in Fig. 1, the central

page_text: shaft being in communication at the bottom by a passage 11° with the corre-
sponding combustion chamber 4, and the outer row of cellular passages 11ª being
in communication at the top with a chimney 12 of suitable size and height. Each
combustion chamber 4 and its regenerator 11, forms one cylindrical structure
enclosed in a metal casing.
Each chimney is provided at the top with a close-fitting valve 13 that can be
opened and closed from the ground by suitable means, as for example through the
medium of a lever 13ª and chain 13b, and also the chimneys have each near its
base, an air inlet passage 14 controlled by an air admission valve 15, which is also
arranged to be opened and closed by suitable means from the ground, as for
example through the medium of a chain 15ª passing over a pulley 15, as in my
previous Specification No. 2720 of 1894.
The mode of working is as follows:-
After a good fire has been prepared in each combustion chamber 4, the valves 13
of both chimneys and the fire doors 8* of both combustion chambers being open to
allow of this being done-the said fire doors are closed; the chimney valve 13
corresponding to say steam generating vessel 1 is also closed and the corresponding
air valve 15 opened, and the chimney valve corresponding to steam generating
vessel 1 is opened and the corresponding air valve closed. Air then enters the
air inlet passage 14 of the regenerator 11 corresponding to the steam generating
vessel 1, such air passing down the outer cellular passages 11d of the regenerator,
and up the inner ones and down the central shaft 11b, as shown by the arrows in
Fig. 1 and at the left hand side of Fig. 3. The air finally emerges from the
passage 11 and impinges upon the fuel in the combustion chamber where rapid
combustion takes place, the resulting flame and hot gases then passing through the
tubes 1 of the steam generating vessel 1. From the rear ends of these tubes, the
hot gases pass by the connecting flue 10 to the tubes 1* of steam generating
vessel 1ª through which they flow, and then pass over the top of the fire in the
corresponding combustion chamber 4 to the central shaft 11" and passages 11ª of the
regenerator above, and thence out through the open valve 13 of the corresponding
chimney 12. After this action has gone on for a sufficient length of time to
considerably reduce the temperature of the regenerator 11 of steam generating
vessel 1 and to increase that of the regenerator of steam generating vessel 1ª, the
direction of the flow of the flame and products of combustion is reversed. To do
this the air valve 15 corresponding to steam generating vessel 1 is closed and, that
corresponding to steam generating vessel 1ª opened, and the chimney valve 13
corresponding to steam generating vessel 1 is opened and that corresponding to
steam generating vessel 1ª closed, so that the combustion of the fuel in the com-
bustion chamber of the second steam generating vessel 1ª will be effected and the
resulting flame and hot gases caused to flow in the opposite direction, so hesting up
the regenerator of steam generating vessel 1 and the air for such combustion taking
up heat stored in the regenerator of steam generating vessel 1ª. Fresh fuel is
added from time to time to the combustion chamber that is being supplied with
heated air, but the fire is preferably allowed to burn down low before reversing, so
that after reversing the hot gases will pass over the fuel without impinging too
much upon it, on their way to the regenerator above.
Each combustion chamber 4, instead of having a solid hearth 5, may be con-
structed in accordance with the invention forming the subject of my before
mentioned application for Patent of even date and which peculiar construction, by
itself is not herein separately claimed. In this case there will be a firegrate with
ash pit that is closed against access of air and is provided with means such as a
pipe by which steam can be introduced thereto when the corresponding combus-
tion chamber is in action the object being not only to prevent excessive heating of
the fire bars at this time but also to increase the heating capacity of the furnace
by the production of combustible gases by decomposition of the steam as it passes
through the bed of ignited fuel. Also, if desirable instead of providing each

page_text: regenerator with a separate chimney and air valve, one chimney may be made_to.
serve both regenerators as in the modified arrangement shown in Fig. 3ª of the
drawings attached to the Specification of my before mentioned Patent.
The air used, may if desired, be either forced or drawn through the regenerators
by means of a fan, or a steam jet, or a compressed air jet, in which case the
chimney or chimneys 12 can be dispensed with.
Fig. 4 is a vertical section on the line I K of Fig. 5; Fig. 5 a sectional plan
half on the line L M and half on the line L' M of Fig. 4; and Fig. 6 a cross
section on the line NO of Fig. 4, showing another arrangement of steam
generating apparatus according to my-present-invention
The steam generating vessel in this case is composed of two cylindrical shells 11*
arranged one above the other and each provided with a number of fire tubes 1*
the two shells being connected together by large circulating tubes 1b in each of
which is fixed a concentrically arranged tube 1 having flaring ends, with the object
of facilitating circulation.
The combustion chamber 4 is arranged opposite the front end of the lower
shell 1 and is provided with ordinary firebars 4" below which is an ash pit 4..
This ash-pit has a water-bottom 4° and is normally closed against access of air by
a hinged flap valve 4 the lower end of which dips into the water constituting the
water-bottom and is thus sealed. The water is gradually converted into steam
which serves to prevent overheating of the fire-grate and by decomposition as it
passes through the bed of ignited fuel, to produce an additional quantity of
combustible gases, as in the arrangement hereinbefore described according to the
invention the subject of my other application for Patent of even date herewith
No. 10815, fresh water being supplied from time to time (it may be by an automatic.
feed) to compensate for that evaporated.
Instead of using a water-bottom, live steam may, for a like purpose, be intro-
duced into the ash pit 4b below the fire bars 4ª according to my other invention
the subject of my application of even date herewith, the ashpit being closed
against access of air by one or more air-tight doors.
At the rear end of the steam generating vessel is a vertical flue, 10 that connects.
the two sets of fire tubes 1* together and serves to carry the hot gases from the
lower set of tubes to the upper one whence they escape into a smoke box or
chamber 10* and thence into a recuperator 11 arranged above the smoke box or
chamber 10 and the combustion chamber 4. The recuperator may be of any
form by which the heat contained in the hot gases passing to the chimney 12 above,.
can be transmitted by continuous conduction through the thin walls of flues tubes
or passages to the air which is being brought in for combustion of the fuel in the
combustion chamber, and which in its passage is brought in contact with such
walls.
The recuperator shown consists of a number of narrow horizontal flues 11ª
separated from a number of similar passages 11e by thin firebrick walls 11ª that.
serve to absorb heat from the hot gases flowing through the flues 11ª and transmit
it to the air flowing through the passages 11. There are several tiers of these
alternately arranged gas flues and air passages, placed one tier above the other,
each gas flue and air passage being connected in an alternate manner to the corre--
sponding gas flues and air passages above and below it so as to impart a zig-zag
course to the hot gases and air respectively, as indicated by the arrows in Figs. 4
and 6. The whole is walled round so as to form a rectangular brick tower, the
lower portion of which contains the combustion chamber 4 and above it the smoke
chamber 10, the upper part containing the recuperator on the top of which is a
chimney 12 into which the flues 11ª constituting the top tier, open.
The air passages 11° of the top tier are open to the atmosphere at one side of
the recuperator as shown at 11', such openings being controlled by suitable
dampers or valves 118 adapted to be operated from the ground as by a chain 11¹..
The flues 11 of the bottom tier are open to the smoke box or chamber 10* of the.

page_text: "steam generating vessel, and the air passages 11 of the bottom tier communicate
by similar but vertical passages 11° with the combustion chambers 4.
:―
The method of working in this case is as follows:-
A good fire is first prepared on the firegrate 4ª of the combustion chamber 4,
coal or other solid fuel being introduced through the normally closed openings 8,
and the dampers or valves 118 for admitting air for combustion into the top tier of
air passages 11° in the recuperator being opened sufficiently for that purpose. The
flame and hot gases, pass through the fire tubes in the lower shell 1" of the steam
generating vessel into the connecting flue 10, then through the fire tubes of the
upper shell 1 into the smoke box or chamber 10* from which the hot gases pass
into the narrow gas flues 11" in the recuperator through which they flow in a zig-
zag course and finally pass off at the top of the chimney. The hot gases in their
course through the recuperator, give up part of their heat to the thin brick
walls 11 which conduct it to the air flowing through the adjoining narrow air
passages 11 on either side, the air thus heated, after traversing the zig-zag course
of the air passages, finally emerging into the combustion chamber 4 in thin streams
that impinge upon the fuel and thus cause efficient combustion thereof.
If desired, the combustion chamber 4 may be provided with a solid hearth, like
the combustion chambers in the arrangement shown in Figs. 1, 2 and 3, instead of
with fire-bars and closed ash-pit with water-bottom.
Although I have shown my invention as carried out with steam generating
vessels of multitubular type, other types can obviously be used.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. An apparatus for generating steam comprising a steam generating vessel,
or vessels, a furnace or furnaces, having a close combustion chamber or chambers
adapted for surface combustion of solid fuel therein, and means whereby air to
support combustion is heated by heat abstracted from the hot gases as they pass
away after they have imparted heat to the boiler heating surface, substantially as
herein described.
2. Steam generating apparatus according to Claim 1 with the steam generating
vessel or vessels arranged between two close combustion chambers adapted for
alternate use and each of which is in connection with a regenerator as and for the
purpose set forth.
3. Steam generating apparatus comprising the arrangement in combination of a
steam generating vessel or vessels, a close combustion chamber adapted for surface
combustion of solid fuel, and a recuperator wherein heat contained in the escaping
hot gases is transmitted by continuous conduction through the walls of flues or
tubes to air on its way to the said combustion chamber, substantially as herein
described.
4. The combination and arrangement of parts constituting the improved
apparatus for generating steam constructed arranged and operating substantially as
herein before described with reference to and shewn by Figs. 1, 2 and 3 of the
drawings annexed, or modified as set forth.
5. The combination and arrangement of parts constituting the improved
apparatus for generating steam constructed arranged and operating substantially as
herein before described with reference to and shewn by Figs. 4, 5 and 6 of the
drawings annexed, or modified as set forth.
Dated this 31st der of Mar 1905
■ Dated this 31st day of May 1905.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.