improvements in or relating to Steam Generator Furnaces.
Year: 1897

page_text: improvements in or relating to Steam Generator Furnaces.
I, EDWARD BROOK, of 7, Water Street, Huddersfield, in the County of York,
Furnace Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to steam generator furnaces of the kind in which air is
supplied under pressure to the ash pit or air chamber under the fuel bearer or
bearers by steam jet apparatus or other mechanical means; and it has for object
to provide means whereby a portion of the air or blast may be passed in a regulated
quantity from the said ash pit or air chamber to the combustion chamber or space
above the fire for the purpose of assisting the combustion of the gases and prevent-
ing the formation of smoke, and also to automatically reduce or lower the pressure
of air in the ash pit or chamber on opening the firedoor in order to lessen the risk
of flame flashing out of the doorway on opening the fire door for the purpose of
throwing coal or other fuel into the fire.
For this purpose the front of the ash pit or air cliamber is closed by a plate
or casting with the exception of an opening formed in the plate immediately
below the level of the deadplate, and the fire door is made sufficiently large to cover
the said opening in addition to closing the doorway above the level of the dead
plate, and is formed with a recess or passage the lower part of which (when the
door is closed) covers the opening into the ash pit, or air chamber, whilst its upper
part is in communication with the combustion chamber or space above the fuel.
The arrangement is such that a portion of the air or blast admitted to the ash
pit or air chamber can pass from the front end thereof, through the recess or
passage in the fire-door to the combustion chamber or space above the fuel when
the fire door is closed, and upon opening the door the ash pit or air chamber will,
through the opening in its front plate, be automatically placed in communication
with the external atmosphere so that the pressure in such ash pit or air chamber
will be reduced and the risk of flame flashing out of the open doorway lessened:
The communication herein referred to between the ash pit or air chamber and the
combustion chamber may be closed or opened by means of a sliding damper or
other suitably constructed valve carried by the door and arranged to control the
recess or passage therein.
The plate or casting at the front of the ash pit or air chamber may be in one with
the plate or casting closing the front end of the combustion chamber and be formed
with an opening, normally closed by a door, for gaining access to the ash pit or air
chamber.

page_text: Improvements in or relating to Steam Generator Furnaces.
I, EDWARD BROOK, of 7, Water Street, Huddersfield, in the County of York,
Furnace 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:
This invention relates to steam generator furnaces of the kind in which air
is supplied under pressure greater than that of the external atmosphere to the ash
pit or air chamber (hereinafter called the ash pit) under the fuel bearer or bearers
by steam jet apparatus or other mechanical devices, and it has for object to provide
means whereby a portion of the air or blast can be passed in a regulated quantity
from the front end of the said ashpit to the combustion, chamber or space above the 1
fire for the purpose of assisting the combustion of the gases and preventing the
formation of smoke, and also to automatically reduce or lower the pressure of air
in the ash pit on opening the fire door in order to lessen the risk of flame flashing
out of the doorway on opening the fire door for the purpose of throwing coal or
other fuel into the fire.
For this purpose the front of the ash pit is closed by a plate or casting with the
exception of an opening formed in the plate immediately below the level of the
dead plate, and the fire door is made sufficiently large to cover the said opening
in addition to closing the doorway above the level of the dead-plate, and is formed
with a recess or passage the lower part of which (when the door is closed) covers 2
the opening into the ash pit whilst its upper part is in communication with the
combustion chamber or space above the fuel.
Fig. 1 of the accompanying drawings shows in front elevation a steam generator
furnace embodying my invention, the fire door being shown open. Fig. 2 is a
longitudinal section on the line y y of Fig. 1, and Fig. 3 is a horizontal section 2
on the line z z of Fig. 1.
1 is the ashpit closed at the front by a plate or casting 2 in which is formed,
below the level of the dead plate 3, a suitable opening 4, 5 is the fire door so con-
structed that when closed it will cover the said opening 4 and also will close the
doorway 6.above, and will provide a recess or passage 7 between the ash pit 1 and 3
the combustion chamber 8. The arrangement, as will be seen, such that a
portion of the air or blast admitted to the ash-pit can pass from the front end
thereof through the recess er passage in the fire door 5 to the combustion chamber
or space.8 above the fuel when the firedoor is closed; and upon opening the said
door 5, the ashpit will, through the opening 4 in its front plate or wall, be auto- 3
matically placed in communication with the external atniosphere, so that the
pressure in the ash pit will then be reduced, and the risk of flame flashing out of
the open doorway be lessened.
In the example shown, air is supplied to the ash-pit 1 by two sets of steam jet
apparatus or blowers, each comprising an air induction pipe 10 having a conical or
bell-mouthed inlet and diverging outlet, and into which a jet of steam is caused
to pass from a steam supply pipe 10° so as to induce air to flow through the pipe
10 into the ashpit as well understood. Or any other known or suitable means
may be used for supplying air under pressure to the ashpit.
The communication between the front end of the ash pit 1 and the combustion 4
chamber 8 may be closed or opened by means of a sliding damper or other suitably

page_text: constructed valve carried by the door and arranged to control the recess or passage 7
therein so as to regulate or arrest the air passing therethrough.
In Figs. 2 and the valve is shown as a butterfly valve 9 consisting of a metal
plate supported at each end by pivots carried by the fire door 5, one or both pivots
projecting through the end or ends of the door and having a knob, hand wheel or
lever 9 attached thereto for the purpose of enabling the valve to be readily opened
or closed.
s
1
:
Fig. 4 shows in front elevation, and Fig. 5 in longitudinal vertical section, a
modified construction of fire door and air regulating valve. In this case the valve
is made as a damper 9 arranged to slide through a transverse opening 11 in the door
and operated by a transverse shaft 12 which is mounted to rotate in bearings 13
carried by the door 5, and is provided with pinions 14 that gear with suitable teeth.
formed with or attached to the valve, a knob or hand-wheel 9 being provided
whereby the shaft 12 can be readily rotated. The opening 11 in the fire door
through which the damper slides may be formed as a horizontal slot about equal
in depth to the thickness of the damper, or there may be formed in the door, as in
the example shown in Fig. 4, a large horizontal opening 11 which is partly closed
by a loose cover 15, so as to leave a smaller opening through which the sliding
damper 9 can pass.
In some cases, as when the chimney draught is sufficiently powerful, the valve 9
may be made shaped, as shewn in Fig. 6, the part 9 fitting into and controlling
the large air opening 11 formed through the door. On rotating the shaft 12, the
valve is moved outwards, as indicated by dotted lines in Fig. 6, thus allowing air to
pass from the ashpit, as indicated by the arrows a, and at the same time permitting
air to be drawn by the chimney draught through the opening 11, as indicated by the
arrows b.
The plate or casting 2 forming the front of the ashpit 1, may, as in the example
shown, advantageously bo made in one with the plate or casting closing the front
end of the combustion chamber 8, and may be formed with an opening 17, normally
closed by a door 18, for affording access to the ashpit. This plate or casting 2 in
addition to carrying the fire and ashpit doors 5 and 18 respectively, also serves to
carry the air supply apparatus 10; 10³.
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. A furnace of the kind herein referred to wherein the front of the ash-pit or
air chamber is closed but has formed in it, below the level of the dead plate, a
suitable opening, and the fire door is so constructed that when closed it will cover
the said opening and also the doorway, and will provide a passage between the
ashpit and the combustion chamber, the arrangement being such that a portion of
the air or blast admitted under pressure to the ash pit can pass from the front end
thereof through the passage in the fire door to the combustion chamber or space
above the fuel when the door is closed, and upon opening the door, the ash-pit will,
through the opening in its front plate or wall, be automatically placed in com-
munication with the external atmosphere, substantially as described for the pur-
poses specified.
2. Providing a fire door constructed and arranged as and for the purpose referred
to in the preceding claim with a sliding or other valve or damper whereby the
flow of air through the recess or passage in the door can be regulated or controlled
substantially as herein-described.
3. The combination and arrangement of parts substantially as hereinbefore
described with reference to and shown in Figs. 1, 2 and 3 or modified according to
Figs. 4 and 5, or to Fig. 6, of the drawings annexed for enabling a regulated
quantity of air under pressure to pass from the front end of the closed ash pit of
a furnace to the combustion chamber thereof above the fuel when the fire door

page_text: is closed and for automatically placing the ash pit in communication with the
external atmosphere when the fire door is opened as set forth..
Dated this 90th day of March 1898
For the Applicant,
W. LLOYD WISE,
46. Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
For the Applicant,
W. LLOYD WISE,
46. Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.