Improvements in or connected with Mechanical Stokers.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with Mechanical Stokers.
We, THOMAS VICARS and JOHN VICARS, both of 56, Seel Street, Liverpool, in
the County of Lancaster, Engineers, do hereby declare the nature of this inven-
tion to be as follows:-
The object of the invention is to provide means, in combination with mech-
anical stoking appliances whereby forced draught may be used in conjunction
with such stoking appliances in such manner that a steady pressure of air may
be maintained both above and below the fire bars with little or no liability
to eddy currents in the furnace, and with no liability to blowing back of the
flame through any interstices or joints of the working parts.
For these purposes we form with or attach to the framework of the stoker a
casing fitting against the front of the boiler or furnace and against the feed
hopper so as to make a tight joint therewith, and projecting in front of the
mechanism for operating the fire bars. The plungers for feeding the coal to
the furnace are also arranged within the casing. The sides of the casing are
closely fitted to the bearings of the shaft for operating the fire bars when, such
shaft passes through the sides of the casing, to prevent escape of air. The front
of the casing is closed by doors arranged so that when they are opened the whole
of the working parts of the stoker are freely accessible, and so that the furnace
may be used with natural draught: and the bottom of the casing is so arranged
that ashes &c. may be readily removed from the furnace. Air is forced into the
casing by a steam jet or fan in any desired way. By the above arrangement a
large space is enclosed so that eddy currents and variations of pressure in the
casing are avoided and there is a pressure of air into the furnace both above and
below the fire bars so that there is no liability of flame being blown back.
Dated this Tighteenth day of December 1899
COMPLETE SPECIFICATION.
Improvements in or connected with Mechanical Stokers.
We, THOMAS VICARS and JOHN VICARS, both of 56, Seel Street, Liverpool, in
the County of Lancaster, Engineers, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly de-
scribed and ascertained in and by the following statement, reference being had
to the accompanying drawings:-
-
The object of the invention is to provide means, in combination with mech-

page_text: anical stoking appliances whereby forced draught may be used in conjunction
with such stoking appliances in such manner that a steady pressure of air may
be maintained both above and below the fire bars with little or no liability
to eddy currents in the furnace, and with no liability to blowing back of the
flame through any interstices or joints of the working parts.
In carrying our invention into effect we make use of appliances such as are
shown on the accompanying drawings where Fig. 1 is a front view partly in
elevation and partly in section of appliances under our invention as applied to
a boiler of the Lancashire type. Fig. 2 is a longitudinal section at the line A A
on Fig. 1. Fig. 3 is a horizontal section at the line B, B on Fig. 1.
For the purposes of the invention we form with or attach to the framework a
of the stoker a casing b which may be formed in several parts as shown for con-
venience of construction. The casing fits against the front of the boiler c, or
the front of furnace. as at c¹ and also against the feed hopper d as at d¹ so as to
make tight joints therewith to prevent escape of air. The casing projects in
front of the ordinary mechanism e for operating the usual reciprocating fire
bars. The plungers f for feeding the coal to the furnace from the hopper d,
and also the plunger operating shaft f¹ are also arranged within the casing so
that air or flame cannot be blown outwards through the joints of the plungers.
The sides of the casing e are closely fitted to the bearings f of the shaft fi and
also to the bearings g¹ of the shaft which operates the fire bars, when such
shafts pass, as shown, through the sides of the casing. This close fitting
is desirable to prevent escape of air around the bearings. The front of the
casing b is closed by doors h so arranged, by being hung on hinges i, that when
such doors are opened the whole of the working parts of the stoker are freely
accessible. The doors h are preferably made to overlap in the centre and are
fastened by catches or bolts of any suitable kind. The doors where they meet
and also at their junction with the casing b are closely fitted so as to prevent
escape of air. When the doors are left open the furnace may be used in the
ordinary way with natural draught. The bottom of the casing b is preferably
so arranged below the bottom of the flue as shown that ashes etc. may be readily
removed from the furnace flue by being drawn into the bottom of the casing
and then up at the sloping surface at k near the front of the casing and out
through the doors. 7 are pipes passing through the top of the casing b, through
which pipes air may be forced into the casing by a steam jet or fan in any desired
way. These pipes or other suitable passages may however be placed in other
positions in the casing as found convenient. In some cases it may be desirable
to lead the air supply through the bottom of the casing near the front. m are
spy holes in the doors h and covered with glass so that the furnace can be
observed without opening the said doors.
By the above arrangements a large space is enclosed by the casing 6 so that
eddy currents which might be caused by the blast from the pipes 7 and variations
of air pressure at different points in the easing are avoided. and there is a steady
pressure of air into the furnace both below the fire bars and also above the fire
hars through the fire door and to some extent through the fuel feed openings so
that there is no liability of flame being blown back through the fire door or any
openings or through any joints of the working parts.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
I claim is:
First, The combination with mechanical stoking appliances of a casing
enclosing the fire bar and fuel feed plunger operating mechanism and fuel feed
plungers such casing being closely jointed to the boiler or furnace front. doors
for closing the front of the casing, and means for admitting air under pressure
to the interior of the casing, substantially as and for the purposes set forth.
Second. The combination with mechanical stoking appliances of a casing

page_text: enclosing the fire bar and fuel feed plunger operating mechanism and fuel feed
plungers such casing being closely jointed to the boiler or furnace the bottom.
of such casing being arranged below the furnace flue and provided with a surface
sloping upwards near the front, doors for closing the front of the casing, and
means for admitting air under pressure to the interior of the casing, substantially
as and for the purposes set forth.
Dated this Seventeenth day of September 1900.
W. B. JOHNSON,
4, Clayton Square, Liverpool, Agent.