Improvements in or in connection with Steam Boiler Furnaces.
Year: 1896

page_text: Date of Application, 12th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in or in connection with Steam Boiler Furnaces.
I, SAMUEL BUTTERWORTII of 173, Rochdale Road, Shaw in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements principally in connection with the
firebars of Lancashire and Cornish boilers though it is applicable to the firebars
of other types of steam boilers and its object is to provide firebars that will
economise fuel and lessen the emission of smoke or in other words tend to effect
more perfect combustion than has hitherto been the case.
In carrying out my invention I dispense with the firebars now in use and which
run parallel to the sides of the furnace and in their place I use firebars placed
at right angles or so to the sides of the furnace. These bars I prefer to make
in sections of say six or more bars, which sections may extend across the full
width of the furnace though I by preference use sections to extend only half
way across the furnace, each section making joint with the section immediately
opposite and side by side with it. The bars composing each section or block
are in plan of a wavy, zig-zag, or undulating character either in a transverse
or longitudinal direction-and are cast in one with one or more transverse welis
which determine their distance apart from each other. At the end of the
block nearest to the side of the furnace the bars may extend a little in teeth-like
form so that the joint between them and the furnace shall not be continuous.
At the end coinciding with the centre line of the furnace they may be formed
in a somewhat similar way but so that the ends of the bars on one block would
pass between the spaces on the other block and so keep the opposite sections in
position. Instead of this arrangement, however, I prefer to let the ends of the
bars nearest the centre come up to or finish off at the transverse web and to make
the latter of an undulating or zigzag character so that the highest or rather more
outstanding parts of each web would interlock with the shallow portions of the
opposite web.
Looking at or viewing the bars from the front of the boiler they are considerably
cambered in the middle, the cambered portion Tising above the level of the
"dead" plate. From the centre the bars decline towards the sides of the furnace
the lowest point at each side of centre of furnace being below the dead plate.
From here the bars rise a little till they reach the furnace sides. The bridge
plate at the farther end of the furnace is also of a similar formation and its upper
surface contrary to general practice, is level with the upper surface of the fire-
bars. It may, however, together with the brick arch be raised above the level
of the firebars. The complete sections of bars making up the total grate surface
are supported by two or more longitudinal bars the front ends of which are dove-
tailed or dowel shaped and fit into correspondingly shaped recesses formed in
the dead plate. The back ends are made of T or similar shape and fit into

page_text: correspondingly shaped recesses in the bridge plate, provision, however, being here
allowed for expansion.
By these means I obtain a grate surface of larger area within the same boundary
as before and as this surface is higher in the middle the fuel is thinner there
because the tendency is for it to slide down towards the lower surface on each
side. This sliding action prevents the formation of clinkers and tends to keep
a cleaner fire than under the old arrangement whilst more perfect combustion is
ensured by reason of the incoming air passing more freely through the centre
of the fire and thus intermixing with the products of combustion rising from
the sides of the furnace.
Dated the 10th day of November 1896.
SAMUEL BUTTERWORTH,
Applicant.
Improvements in or in connection with Steam Boiler Furnaces.
I, SAMUEL BUTTERWORTH late of 173 but now of 180 Rochdale Road, Shaw,
near Oldham, in the County of Lancaster, Engineer, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
This invention relates to improvements principally in connection with the fire-
bars of Lancashire and Cornish boilers though it may be applied to the firebars
of other types of steam boilers and its object is to provide firebars that will
economise fuel and lessen the emission of smoke from the furnace or in other
words tend to effect a more perfect combustion of fuel than has hitherto been
the case.
My invention will be fully described with reference to the accompanying
drawings in which
Fig. 1 is a side elevation of the "dead" plate and bridge plate connected
together by longitudinal bars.
Figs. 2 and 3 front elevation and plan of the "dead" plate.
Figs. 4 and 5 similar views of the bridge plate and
Figs. 6 and 7 front elevation and plan of sections of the firebars proper.
In carrying out my invention I dispense with the ordinary firebars now in
use and which run parallel to the sides of the boiler furnace and in their place
use firebars placed at right angles or so to the sides of the furnace. These bars
I prefer to make in sections A. (Figs. 6 and 7) of say six or more bars a, which
sections may extend across the full width of the furnace A', though I, by pre-
ference, use sections to extend only half way across the furnace, as shown in
Figs. 6 and 7, each section making joint with the section immediately opposite,
at the centre B, or thereabouts, and those alongside it. The bars a comprising
each section or block A are, in plan, of a straight, wavy, zigzag or undulating
character as shown, and are cast in one with one or more transverse webs b which
determine their distance apart from each other and which moreover, may also
be made of a sinuous character instead of being straight as indicated in the draw-
ings. At the end of each section or block A nearest to the sides of the furnace A,
the bars a are extended in teeth-like form a¹ so that the joint between their ends
and the furnace sides shall not be continuous. At the end coinciding with the
centre line of the furnace, or there-about, they may be formed in a somewhat
similar way. The method I adopt is to form teeth-like projections C on one

page_text: section A and on the section immediately opposite a straight or sinuous transverse
web c which, of course, really forms one of the webs connecting the bars a.
The projections C do not come into contact with the web c but leave a little space
between them so that in replacing a section A, the latter may be taken out and
the others pushed along the longitudinal supporting bars and the new section be
dropped in at the front of the furnace, if desired.
Instead of forming the ends as just described, the ends of the hars a on one
block may pass between the ends on the opposite section, or cach block may
terminate in a straight or sinuous, xig-zag or similarly formed web, each web
interlocking or not with the other.
One of the principal features of my invention consists in the peculiar formation
of the upper surface of the sections A. For instance, looking at, or viewing,
the sections of bars a from the front of the furnace they are considerably cambered
at or about their central portion D, the cambered portion rising say some two
or three inches above the level of the dead plate E. From the centre, the bars
decline towards the sides of the furnace, the lowest points being say, some two or
three inches below the level of the dead plate, or at F. I do not, however confine
myself to the stated dimensions. From the point the hars again rise towards
the sides of the furnace as shown. Those portions of the dead plate E and bridge
plate H nearest to the bars a are made of a similar charcter to the latter so far
as their upper surface is concerned, the surface in the case of the dead plate
gradually declining towards the front of the furnace, as shown in Fig. 1, until
it is level with the flat portion g of the plate. The flat portion is supported
at the front of the furnace in the usual way. The upper surface of the bridge
plate H, or some portion of it, such as h may be raised above the level of the
firebars and have formed in it, if required, air holes A. By means of the holes h
and the space A in the bridge plate the air can freely circulate and therefore
stimulate combustion near the bridge of the furnace. The brick arch J. may be
level with the fire bars or raised above them and the bridge plate, if desired,
but I find that the best results are obtained by making it as shown in Fig. 1,
and letting the part of the bridge plate H. take the place of the top part of
the brick arch and be not more than an inch or two higher than the highest
portion of the firebars.
The complete sections A of firebars making up the total grate surface of the
furnace are supported by two or more longitudinal bars K, the front ends of which
are dovetailed or dowel-shaped and fit into correspondingly shaped, recesses
formed in the dead plate E. The rear ends of the bars K are made of Tor
similar shape and are passed through correspondingly shaped holes formed in
the bridge plate the T shaped ends being of such a character as to admit of the
bars K expanding under heat without injury.
By the means described I obtain a grate surface of larger area than hitherto
within the same boundary, or the same area of grate surface in less space, and
as this surface is higher in the centre than at other parts the fuel is thinner there
because the tendency is for it to slide down towards the lower surface at each
side. This sliding action prevents the formation of clinkers and tends to keep
a cleaner fire than under the old arrangement, whilst more perfect combustion
is ensured by reason of the incoming air passing more freely through the central
portion of the fire and thus intermixing with the products of combustion rising
from the sides of the furnace. By the improved arrangement I am also enabled
to utilise an inferior class of fuel and yet obtain equally good results of steam
generation.
In conclusion I would have it understood that the details of construction may
be departed from without affecting the spirit of the invention and also that I
am aware that firebars running transversely of the boiler furnace have been in
use prior to the date of my invention and that some of these have had centrally
cambered surfaces. I am also aware that firebars have been made in sections.
To none of these do I lay claim; but

page_text: Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
do claim is:—
1. Firebars for Lancashire or other boilers constructed in sections, said sections
consisting of straight, wavy, zig-zag or similarly formed longitudinal and trans-
verse bars the upper surfaces of which are cambered in their central portions
from which they decline and again rise to the sides of the furnace, substantially
as and for the purposes described.
2. The general arrangement and combination of parts-consisting of firebar
sections, as referred to in Claim 1, dead plate, bridge plate and longitudinal
supporting bars-forming my improvements in firebars, constructed and arranged
substantially as described and as shown in the accompanying drawings.
Dated this 10th day of August 1897.
WILLIAM H. TAYLOR,
Swan Chambers, 69, Market Street, Manchester, Agent for the Applicant.