IMPROVED APPLIANCES FOR STEAM BOILER FURNACES
Year: 1885

page_text: HENRY CALLAS, 4 Kemble Street W.C. London in the County of Middlesex,
Engineer do hereby declare the nature of my invention for IMPROVED APPLIANCES
FOR STEAM BOILER FURNACES to be as follows:-
My invention relates to improvements in the Fire Doors, and Fuel Supports or
Grate Bars of the furnaces for Marine, Land and Locomotive Steam Boilers, and
in perfecting these improvements my principal object has been to place within the
reach of all users of Steam Power, a furnace, combining in an extremely simple,
inexpensive yet eminently scientific manner, and without the aid of any complicated
machinery, all that is necessary for obtaining the most perfect combustion
practically attainable.
From actual experience, I am perfectly satisfied the demand for oxygen above
the burning fuel in furnaces, is not intermittent but constant, and to make the fire
doors of my furnaces available for assisting to supply the demand for oxygen,
I provide a suitable opening for the admission of air in the door itself, and attached
to the door is a lining or inner door with plain solid sides, but having its face
surface formed by a series of ridges and furrows, in which are provided a suitable
number of slits or perforations. In the space between the front and inner doors,
I place a solid plate or diaphragm of metal, so constructed as to leave an open
space between its edges and the solid sides of the inner lining, this diaphragm is
supported on the pins that connect the front and inner doors, and is so arranged
that it can be used to entirely close the opening for air in the front door, or be
permanently fixed in such a position as to admit the quantity of air considered
desirable. The air in passing from the opening in the front door to the body of
the furnace, through the perforations in the inner door, is compelled to impinge on
the surface of the diaphragm, having its temperature greatly increased before
entering the furnace.
As my furnaces are intended for using either Anthracite or Bituminous coal, I use
a form of grate bar specially adapted for the purpose.
For forced fires, or
Anthracite, I make my grate bars with a castweb, the top surface, or actual fuel
supports, being formed of ordinary wrought bar iron, cut off to any desired length
for forming the width of the grate bar, and placed either at right angles, or
obliquely to the axis of the main web.

page_text: To produce this furnace grate bar, a pattern is made in the ordinary manner for
moulding from it, and when the pattern is removed from the sand, the impressions
of the fuel supports are filled up with the peices of wrought bars beforementioned,
the space for the main web is of course left vacant, and when the molten cast iron
is poured in, it will unite with the wrought bars, forming a strong furnace grate bar
of cast and wrought iron. For locomotive furnaces, I prefer to use this bar in the
form known as the rocking bar, my improvement being the making of the rocking
arm or lever separate from the bar itself, the journal of the bar merely resting in
a seat in the arm, which works in a seating provided for it, in a bearing bar
suitably adapted for the purpose.
For ordinary furnaces when only bituminous coal is used, I make my furnace
bars in sections of suitable length and width, using two, or more sections to form
one complete bar. The sections have V shaped supports at each end which rest on
a correspondingly shaped bearing bar. When the bearing bars are once in place,
they will never require renewal; but when any particular section, forming the grate
bar, is worn out, it can be at once easily replaced by a new one, whereas, in
ordinary grate bars, if only a small portion of one is destroyed, the entire bar must
be renewed. When it is desirable to do so, I use next the bridge wall of the
furnace, sections having at one end, an opening adapted to receive a short socket,
for the purpose of conveying air from the ash pit, to the top surface of the fuel,
near the bridge wall. When in certain cases, I am obliged to use a narrow furnace
grate bar, I make its top surface of a zig-zag forin, or a series of short straight
lines placed at right angles to each other, so as to ensure an uniform width of
metal being exposed to the action of the fire, this is important for increasing the
longevity of the bar itself, but more particularly for the thorough diffusion of air
through the burning fuel.

page_text: COMPLEIE DIECIFICATION.
Improved Appliances for Steam Boiler Furnaces.
I HENRY CALLAS of N° 4 Kemble Street in the City of London in the County
of Middlesex, 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 :-
My Invention relates to improvements in the fire doors and fuel supports or
grate bars of the furnaces of marine, land and stationary steam engine boilers.
The arrangements for admitting air through the fire door are specially designed
to regulate the admission of air in the proportion and manner best suited for
preventing waste of fuel and heat.-It is important to avoid either excess or defect
in the supply of air to the furnace the former involving waste of fuel and the
latter waste of heat.
From actual experience I have found that the demand for a supply of oxygen
above or over the burning fuel is not intermittent but nearly constant, and for
this purpose the air should be admitted through the door in finely divided streams
caused to pass into the furnace in a heated state and without undue velocity. And
it is in order to fulfil these conditions that the door is constructed and its parts
arranged in the manner hereinafter described.
I provide a suitable opening for the admission of air in the door itself, and fitted
thereto is a lining or inner door with plain solid sides hut having its surface
corrugated or formed with a series of alternate ridges and furrows in which are
provided a suitable number of slits or perforations adapted to divide the admitted
air into fine streams as required. In the space between the front and inner doors
there is inserted a solid plate or diaphragm so constructed as to leave an open
space between its edges and the solid sides of the inner lining. This diaphragm is
supported by and slides on the pins that connect the front and inner doors, and is
so arranged that it can be made either to entirely close the opening for air in the
front door or be permanently fixed in such a position as to admit any required
quantity of air. The air in passing from the opening in the front door to the
body of the furnace through the slits or perforations in the inner door, is caused to
impinge on the surface of the diaphragm and receive a considerable increase of
temperature before passing through the said slits or perforations. The corrugated
surface of the inner door prevents it from becoming overheated owing to the
radiating heat impinging obliquely on such surface.
As my furnaces are intended for the use either of anthracite or large or small
Bituminous coal, I use a form of grate bar specially adapted for the purpose. For
forced fires or anthracite I make my grate bars with a cast iron or steel web the
actual fuel supports or top surface of the bars being formed of ordinary wrought
iron bars cut off to any desired length to form the width of the furnace bars and
placed either at right angles or obliquely to the axis of the main bar. In order to
produce this furnace bar a pattern is made in the ordinary manner for moulding
from it, and when the pattern is removed from the sand after moulding the

page_text: Figures 1. 2 and 3 relate to the improvements in fire doors.
Fig: 1 is a front elevation of the door-Fig. 2 is a vertical section on the line A. B
of Fig. 1 and Fig. 3 is a horizontal section on the line CD of Fig. 1. E is the
opening in the front of the door for the constant admission of air.
F is the lining
or inner door which is corrugated as shewn in Fig. 3 and perforated as shewn in
Figures 2 and 3. G is the diaphragm fitted between the opening E and the lining
or inner door F and is supported on the pins H H which connect the front and
inner doors. The diaphragm G is made so as to leave a space round its edges for
the passage of air and is fitted with an adjusting screw I by means of which it can
be moved on the pins either so as to entirely close the opening E and prevent the
admission of air thereat, or be securely fixed in position by means of a set nut as
shewn so as to admit any required quantity of air. Assuming the diaphragm G to
be in the position shewn in Figures 2 and 3 the external air on entering at the
opening E will be caused to impinge on the diaphragm G by which the temperature
of the air will be raised, which diaphragm will also act as a baffling plate and cause
the warm air to pass rounds the edges of it into the space between the diaphragm
and the inner door F, whence it will pass through the slots or perforations therein
and enter the furnace in divided streams as required. The corrugated surface of
the inner door F will serve to prevent the air from becoming over-heated as
required in order to ensure the supply of a greater amount of oxygen than would
be the case if the air were to be more highly heated and correspondingly expanded
before entering the furnace.
By the combined apparatus or means above described, it will be seen that the
admission of air through the door may be made constant, also that it will become
moderately heated and be eventually introduced into the furnace in divided streams
in such a manner as to enable it to mix readily with the combustible gases therein,
thereby insuring their ignition.
I is a sight hole through which the action of the fire can be observed.
Figures 4 to 15 relate to my improvements in fire-bars.
In figures 4. 5 and 6 are represented in longitudinal elevation transverse section
and plan or horizontal view, ny mode of constructing grate bars adapted for use in

page_text: forced fires or those actuated by a blast when anthracite or refractory coal is used.
K is the cast iron or steel web, L L are the supports for the fuel consisting of wrought
iron bars cut off to any desired length in order to form the width of the bars as
shewn in Figures 4 and 5. In Figure 4 the supports L, L, are shown as placed
obliquely in order to enable the pricking bar to pass readily over the surface of the
bars when placed longitudinally in the furnace. The mode of producing these bars
has been herein before described.
Fig. 7 is a half end view and half section of a boiler fitted with my improved
rocking or dumping bar showing the rocking or dumping levers M M. Fig. 8 is
a longitudinal section and Fig. 9 a horizontal section on the lines B B and C. C.
of Fig. 7.
Fig. 10 is a side elevation of a detached grate bar having a raised fuel supporting
surface of a zig-zag form composed of a series of straight lines placed at right angles
to each other.
Fig. 11 is a transverse vertical section and. Fig. 12 a plan or horizontal view of
the same. Fig. 13 is a section on an enlarged scale of one of the frames of bars
shown in Figures 8 and 9. Fig. 14 is a plan or horizontal view of the same and
Fig. 15 is a section on the line x. y. of Fig. 14.
In the foregoing figures 8 to 15 are shewn my special construction of fire-bars in
order to insure an uniform thickness of metal throughout the metal supports
exposed to the action of the fire and an equal distribution of air spaces between
such supports, thereby adding to the durability of the bars in use or working.
In Figures 10 11 and 12 K is shewn a cast iron bar having raised fuel supports L L
arranged so as to admit of the passage of the air between them as indicated by the
arrows in Fig. 12 In this figure also the fuel supports L are shown of uniform
thickness throughout.
In Figures 8 and 9 are shewn frames or sections N for holding separate, bars such
frames consisting of only two sides and the two ends the intermediate space being
filled up with loose grate bars which rest in seatings made in the ends of the frames
to receive them, so that any particular bar can be readily removed and replaced as
required without removing the frame.
The frames or sections N N are also shewn on an enlarged scale in Figures 13
and 14 together with the arms or levers O. O. by which they are worked through
the levers M M shewn in Figures 7. 8 and 9, one lever on one side of the grate
acting on the front frames and the other lever acting on the hinder frames. In
Figures 14 and 15 P is a portion of the shell of the boiler, Q is the bearing bar on
which rests the arm or lever O, in which is a seating for the journal R of the fire-bar
frame N. By this arrangement the several frames N N can be rocked or dumped
as required by means of the levers M M being connected to the ends of the arms
or levers O. O. and moving the frames N N on their journals R R while the arms
or levers O. O. are separate from the bars and rest on the bearing bar as above
described.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
First. The fire-door for steam boiler furnaces so constructed as to be capable of
a constant admission of air warmed and in divided streams substantially in the
manner described.
Secondly. In such fire-door for steam boiler furnaces, the combination of an
aperture for the constant admission of air with an adjustable regulating diaphragm,
and a corrugated inner door or lining with slits or perforations therein, substantially
as and for the purposes described.
Thirdly. The construction of grate-bars of wrought and cast iron combined,
the fuel supports being composed of wrought iron substantially as described and
represented in Figures 4. 5. and 6 of the drawings.

page_text: Fourthly. The construction of fire-bars as represented in Figures 10. 11 and 12
and described, whereby the fuel supports are of uniform thickness in the parts
exposed to the action of the fire with longitudinal and transverse air spaces
uniformly distributed, all substantially as and for the purposes described.
And lastly. The method of constructing the frames composing the rocking bars
whereby such frames can readily be removed without interference with the connecting
gear, in the manner substantially as hereinbefore described.