Improvements in Furnaces.
Year: 1891

page_text: Date of Application, 10th Nov., 1891-Accepted, 19th Dec., 1891
COMPLETE SPECIFICATION.
Improvements in Furnaces.
I, ABSALOM BACKUS, Junior of 80, Trumbull Avenue, Detroit, in the County of
Wayne and State of Michigan, United States of America, Lumber and Planing
Mill Owner 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 an improvement in furnaces, and has for its object to
provide a furnace of exceedingly simple, durable, and economic construction, and to
provide a means whereby perfect combustion will take place and a uniform maximum
degree of heat may be obtained, and a decided economy in the use of fuel.
.
The invention consists in the novel construction and combination of the several
parts, as will be hereinafter fully set forth and pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar figures and letters of reference indicate corresponding
parts in all the views.
Figure 1 is a longitudinal vertical section through a furnace embodying my
improvements;
Figure 2 is a section taken practically on the line cx of Figure 1; and
Figure 3 is a horizontal section through the fire chamber, taken above the grate
on the line y-y in Figure 2.
The bridge wall 10, of the furnace, is connected at its upper end with the rear
end of an arch 11, located within the fire chamber A, which arch is so placed that
a suitable space intervenes between it and the grate 12, and also between it and the
boiler 13, when the furnace is employed for heating the latter.
The arch extends from side to side of the fire chamber, and terminates longi-
tudinally at a point at or near the centre of the grate or the fire chamber, as is best
illustrated in Figure 1.
The inner end of the grate 12, is supported upon an L or U-shaped bar 14, the
ends of which are secured in the sides of the fire chamber, the said bar being located
some distance in front of the bridge wall 10. The grate may be of any suitable or
approved construction.
Upon the upper horizontal member of the angle bar or beam 14, the forward ends
of a series of spacing bars 15, are supported, the rear ends of which bars are seated
in the bridge wall 10, as shown in Figures 1 and 3. Between the spacing bars 15
a series of gates or dampers 16, is pivoted at their forward or outer ends; the inner
or rear ends of which gates or dampers, when the said dampers are closed, are
adapted to rest upon a shoulder 17, formed in the bridge wall, as shown in
Figure 1, or the said dampers may be otherwise supported, if in practice it be found
desirable.
Each damper has preferably secured to its free end the upper extremity of a
toggle lever 18, the lower ends of the toggle levers being pivoted to any suitable
support formed preferably upon the floor of the ash pit A. To the middle joints
of the toggles are jointed rods 19, which extend below the grate and out through
the front of the ash pit opening, being guided by suitable staples 20, or their
equivalent.
In operation, the amount of air to be supplied to the fire is regulated by the
manipulation of the rods 19, to open or to close the dampers, or to partially open or
close them. The air is supplied to the grate through the ash pit opening, from
whence, when the dampers are open, it passes upward through the spaces at the
rear of the grate, under the arch, and is deflected thereby and forced downward
upon the fire; and, after passing over the fire, the air, together with the products

page_text: .
of combustion passes up over the arch 11 and is there super-heated, and from thence
the products of combustion, which by reason of the oxygen mingled with them, are
in a high state of combustion, pass through the tubes of the boiler and out through
the offtake flue of the furnace.
It will be observed that the air admitted is under perfect control, and that the
heat may come in contact with the boiler throughout its entire length, no obstructions
being in the way. It will be further observed that the arch serves the purpose of a
super-heater, thereby adding materially to the intensity of the heat below the centre
of the boiler.
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. In a furnace, a bridge wall having an arch connected therewith, extending
within the fire chamber over the grate, and also provided with a space between the
grate and the bridge wall, and upward opening dampers located within the said
spaces, with their rear edges next to the bridge wall, as and for the purpose
specified.
2. A furnace provided with an arch connected with the top of the bridge wall
and extending within the fire chamber some distance over the grate, and also
provided with an opening beneath the arch between the grate and the bridge wall,
upward opening dampers located within the said openings with their rear edges next
to the bridge wall, and a mechanism for opening or closing the dampers, substantially
as specified.
3. In a furnace, the combination, with the fire chamber and an arch located at the
rear portion of the fire chamber and connected with the bridge wall or back of
the fire chamber, of a grate of less length than the fire chamber, located beneath the
arch, whereby a space intervenes between the grate and the bridge wall or back of
the chamber, upwardly opening dampers pivoted in the said space with their lear
ends resting on a stop or shoulder 17 on the bridge wall, and a shifting mechanism,
substantially as described, connected with the dampers, whereby they may be raised
or lowered, as and for the purpose specified.
Dated this 10th day of November 1891
ABSALOM BACKUS, JR.
By A. M. & Wm. Clark,
53. Chancery Lane, London, Chartered Patent Agents.