IMPROVEMENTS IN FURNACES
Year: 1877

page_text: LETTERS PATENT to John Hazell Fraser, of the Firm Fraser Brothers, of
Bromley-by-Bow, in the County of Middlesex, Steam Boiler Manufacturers,
for the Invention of "IMPROVEMENTS IN FURNACES."
Sealed the 22nd January 1878, and dated the 24th July 1877.
PROVISIONAL SPECIFICATION left by the said John Hazell Fraser at the
Office of the Commissioners of Patents on the 24th July 1877.
JOHN HAZELL FRASER, of the Firm Fraser Brothers, of Bromley-by-Bow, in
the County of Middlesex, Steam Boiler Manufacturers. "IMPROVEMENTS IN
FURNACES."
"
This Invention is designed to secure, in addition to facility in feeding, more
perfect combustion of solid fuel than obtains in furnaces as at present usually con-
structed, and also the ready removal of the ashes and debris from the furnace or
combustion chamber. For these purposes sets of moving bars arranged one set
above another are employed in such manner that the fuel having been fed by a
hopper or otherwise on to the upper set of bars is whilst burning caused to travel
towards the opposite end (or side) of the furnace or combustion chamber, where it
falls on to a lower set of moving bars, whereon the fuel is returned to the feeding end
(or side) of the furnace or combustion chamber.
In conjunction with the sets of moving bars as described, a guide or deflector
may be arranged to guide the fuel in its descent from the upper to the lower sets of
bars.
The ashes and debris may be allowed to fall into a receptacle placed to receive
them, or may be permitted to accumulate behind a suitable door in readiness for
being removed as may be desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Hazell Fraser in the Great Seal Patent Office on the 24th
January 1878.
JOHN HAZELL FRASER, of the Firm Fraser Brothers, of Bromley-by-Bow, in
the County of Middlesex, Steam Boiler Manufacturers. " IMPROVEMENTS IN
FURNACES."
This Invention is designed to secure, in addition to facility in feeding, more
perfect combustion of solid fuel than obtains in furnaces as at present usually con-
structed, and also the ready removal of the ashes and debris from the furnace or
combustion chamber. For these purposes sets of moving bars arranged one set
above another are employed in such manner that the fuel having been fed by a
hopper or otherwise on to the upper set of bars, is, whilst burning, caused to travel
towards the opposite end (or side) of the furnace or combustion chamber, where it
falls on to a lower set of moving bars, whereon the fuel is returned to the feeding
end (or side) of the furnace or combustion chamber.
In conjunction with the sets of moving bars as described a guide or deflector
may be arranged to guide the fuel in its descent from the upper to the lower sets of
bars.
The ashes and debris may be allowed to fall into a receptacle placed to receive
them, or may be permitted to accumulate behind a suitable door in readiness for being
removed, as may be desired.
My Invention will be readily understood on reference to the accompanying
Drawings, which illustrate one way of carrying my Invention into effect.
Figure 1 is a section, and Figure 2 a front view of a boiler with my moving bars
applied.
A is the upper furnace, and B the lower, each having a set of moving bars C, D,
as plainly shown, and in this instance in endless form passing round rollers at the
front and back of the furnace, the front rollers E, E, revolving in bearings G, G, at
the mouth of the furnace, whilst the back rollers H, H, are carried in a similar
manner within and at the back end, as indicated, the lower set of moving bars being
somewhat longer, and projecting slightly further into the boiler than the upper one
for a reason which will presently be explained.
The fuel is conveyed to the hopper K by a Jacob's ladder, or by manual labour or
otherwise as found convenient, from whence it descends by the guide shoot or
casing L to the front end of the upper set of moving bars C, when it becomes
ignited from the incandescent fuel thereon, and travels slowly towards the back end
of the furnace, at which point it falls on to the projecting back end of the lower
set of moving bars D (they being slightly longer to enable them to catch the partly
burnt fuel as it falls), on which bars it returns with a slow motion at any given
speed until it arrives at the mouth end or front of the furnace, by which time the
fuel is completely burnt, and the ashes and other debris are discharged into a
receptacle placed to receive them, or as desired. The water tubes M serve as
deflectors or guides to the burning fuel as it falls from the upper to the lower set
of bars, at the same time being good generators of steam.
It will be observed that the motion of the top face of the upper set of bars is
inwards, while that of the lower set is outwards, as indicated by the arrows, the
motion being obtained by the worm gearing N, N, as clearly shown, which is
driven from a prime mover, or as desired.
The feed of fuel, which is to the upper furnace only, is controlled by the adjustable
slider P, which regulates the amount of opening at the bottom of the casing L, and
consequently the quantity of fuel which in a given time can pass on to the travelling
bars C, this slider being connected by the chain Q to the balance lever and weight
R carried on the standard S on the top of the boiler.
In the Drawings annexed though I have shown my Invention arranged to cause
the fuel to move from front to back of the furnace, and then to return, it is evident

page_text: I can arrange it so that the movement may be from side to side if desired; neither
is it necessary that the fire-bars should have a continual movement in their
respective opposite directions required by the upper and lower set of bars, as any
noving bars which from their motion will cause the fuel upon them to move so
that it can travel so to speak from its point of entry to its point of discharge can be
made available for the purposes of my Invention; also the upper furnace may be
fitted with moving bars in endless form, and the lower with moving bars not in
endless form, or the lower furnace may have the endless bars if desired.
It is obvious that my Invention though described and shown as applied to a steam
boiler furnace, is applicable to other furnaces.
The advantages of my Invention are,―
1st. Facility of feeding the fuel to the furnace.
2ndly. More perfect combustion of the fuel and avoidance of smoke.
3rdly. A perfect distribution of the fuel upon the bars.
4thly. Facility of removing the ashes and debris from the furnace.
5thly. Fuel of the commonest quality can be utilized in boilers fitted and arranged
according to my Invention.
Having now described the nature of my said Invention, and in what manner the
same is to be performed, I declare that I claim,-
The improvements in furnaces herein-before described and substantially as shown
in the annexed Drawings, consisting of two sets of moving bars arranged in endless
form in furnaces one above the other in combination with a hopper, whereby the
fuel is fed on to the top set of moving bars, where partial combustion takes place,
thence passing to the lower set, where the process of combustion is completed, and
the ashes and other debris discharged as set forth.
Secondly. I claim arranging two furnaces one above the other in combination
with a hopper, each furnace containing a set of moving bars, whereby the fuel is
caused to travel along the face of the top set of bars, and to return along the face
of the bottom set of bars, whence the ashes and debris are discharged.
In witness whereof, I, the said John Hazell Fraser, have hereunto set my
hand and seal, this Twenty-fourth day of January, One thousand eight
hundred and seventy-eight.
JOHN HAZELL FRASER. (L.S.)