Improvements in Fire Grates and Furnaces of Steam Boilers.
Year: 1896

page_text: Date of Application, 16th Apr., 1896
Complete Specification Left 5th Sent 1806 Accented 17th Oct
1806
PROVISIONAL SPECIFICATION.
Improvements in Fire Grates and Furnaces of Steam Boilers.
I, SAMUEL ALBERT JOHNSON of No. 130 High Street Poplar in the County
of London Marine Engineer, do hereby declare the nature of the said invention to
be as follows:-
This invention has for its object improvements in fire grates and furnaces of
steam boilers whereby more perfect combustion is ensured, the furnace bars will not
burn or clinker and at the same time small coal may be used.
According to this invention I construct a fire grate or furnace of any desired
pattern but instead of employing cast iron fire bars as at present I employ a
series of metal tubes, a distance apart and extending the whole length of the
furnace.
The inner ends of these tubes are connected to and pass through an iron box or
chest situate in the rear of the fire bridge, such box or chest is in connection with
the main boiler.
To secure these tubes, which pass through the box or chest, and which form the
bed of the furnace I provide them with lock nuts and caps, and to ensure the
proper free circulation of the water, ports or openings are provided near the ends
of the tubes in the said box or chest.
The outer ends of the tubes are similarly connected to another box or chest
outside the furnace which is in connection with the steam chamber of the boiler,
thus the steam generated in the tubes will pass to such steam chamber.
The spaces between the tubes forming the bed of the furnace are filled in with
ordinary fire bars which are capable of being raised by means of a lever or
suitable apparatus, from the stoke hole, thereby ensuring proper combustion when
using small coal.
Dated this 16th day of April 1896.
.COMPLETE SPECIFICATION.
Improvements in Fire Grates and Furnaces of Steam Boilers.
I, SAMUEL ALBERT JOHNSON, of No. 130 High Street Poplar in the County
of London, Marine 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 has for its object "Improvements in fire grates and furnaces of
steam boilers," whereby more perfect combustion is ensured, the furnace bars will
not burn or clinker and at the same time small coal may be used.
According to this invention I construct a fire grate or furnace of any desired
pattern, but instead of employing cast iron fire bars as at present, I employ a
series of metal tubes a suitable distance apart extending the whole length of the
furnace, and having water continually circulating through them.
The inner ends of these said water tubes are connected to and pass through an
iron box or chest situate in the rear of the fire bridge. such box or chest being in
connection with the main boiler.
3

page_text: Te secure these tubes which pass through the box or chest, and which form the
bed of the furnace, I provide them with nuts and caps, and to ensure the proper
free circulation of water through the said tubes, ports or openings are provided
near the ends of such tubes in the said box or chest.
The outer ends of the tubes are similarly disposed and connected to another box
or chest outside the furnace which is in connection with the steam chamber of the
boiler, thus the steam generated within the tubes is permitted to pass freely into
the said steam chamber.
The spaces between the tubes forming the bed of the furnace are filled in with
ordinary fire bare, which are capable of being raised by means of a lever or suitable
apparatus from the stoke hole thereby ensuring proper combustion when using
small coal,
In the accompanying two sheets of drawings hereunto annexed I have shewn my
method as applied to a Cornish boiler, wherein as at
Sheet 1. Figure 1. exhibits a longitudinal section of same, and Figure 2 a front
elevation.
In Sheet 2-Fig. 3, shews a cross or longitudinal sectional plan of the furnace,
and Fig. 4 an underneath or bottom plan of same looking upwards.
Figure 5. a cross section of the front portion of the boiler, and, Fig. 6, an
enlarged detached horizontal sectional view of a portion of one of the circulating
water tubes, and method of fitting or securing them in position at the ends of each
of the respective front and rear circulating water chambers.
In the several views as shewn in the drawings Sheets 1 and 2-it will be
understood that the letters given thereto refer to like, or corresponding parts
throughout same-wherein A. A. are the metal circulating water tubes extending
the whole length of the furnace.
The inner ends of these tubes A. A. 'with water circulating through them,
pass through an iron chest, or circulating water chamber B, at the rear of the fire.
bridge C.
The said iron chest or circulating chamber B, would be connected to the lower
portion of the main boiler by means of the water pipe or tube D. as more
particularly shewn at Fig. 4-Sheet 2.
The outer ends of the tubes A A. are likewise connected to, and pass through
an iron chest or circulating chamber E, at the front or outside part of the boiler,
and to which a steam pipe or tube connections F F are connected which com-
municates with the steam chamber of the main boiler as shewn at Figures, 1 and 2
Sheet 1:
The tubes A A are suitably spaced apart to receive the ordinary class of fire
bars G. G, which are so arranged as to be capable of being raised or tilted
upwards at the fore or front portion of the furnace which would be effected by
means of a lever H. and cross. bar connection H', just under and across the fore
portions of the respective fire bars working on a pivot, and supported by the under
frame K. as shewn in the several figures (but more particularly as in Fig. 1). The
leverage being applied by means of a bar connection L, and lever handle L, with
socket to fit thereon so as to be readily applied, and taken off as may be required,
and the raising or tilting of the fire bars upwardly at the fore or front portion of
the boiler would be effected as in manner described, or other suitable mechanical
means for raising or lifting same may be employed to admit of the required admission
of air as shewn by the dotted lines at Figures 1. Sheet 1, and by the cross section
of the flue portion of the furnace Fig. 5. Sheet 2.
The circulating water tubes A. A. which respectively pass through the circulating
chambers B and E, would have screw nuts O, and caps M, to permit of their being
screwed up, or taken off when required, and with necessary washers to ensure
their being suitably and securely held in position so as to be water and steam
tight.
Near the ends of the tubes A A. ports or openings N. N. would be formed for
the free admission and circulation of water from the boiler.

page_text: The said ports or openings N. N. as provided would be formed within each of
the respective circulating chambers C. and E.
In the enlarged detailed sectional view Fig. 6. Sheet 2, both the method of
securing the tubes by the aforesaid nuts and caps, likewise the ports or openings
within the chambers will be more clearly seen.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The use or employment of water tube fire bars or tubes in connection with
circulating water chambers at the back and front and in direct communication with
the main boiler.
2. In the particular method of arranging fire bars so that they may be tilted or
raised at the front portion of the boiler for the required admission of air and
regulated by a lever at the stoke hole end, and at will, for burning fine or dust
coal, sawdust or other refuse of waste from wood working machinery as in manner
and for the purpose herein set forth, illustrated and described.
Dated this Fifth day of September 1896.
S. A. JOHNSON.