Improvements in Air-heating Stoves.
Year: 1892

page_text: Date of Application, 3rd Nov., 1892-Accepted, 11th Mar., 1893
COMPLETE SPECIFICATION.
Improvements in Air-heating Stoves.
I, SAMUEL CLELAND DAVIDSON, of Sirocco Works, Belfast, Ireland, Merchant,
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 reference to air-heating stoves of the class or type described
in the Specification of previous Letters Patent granted to me No. 2703 and dated
15th February 1889 (which Specification is hereinafter referred to as the previous
Specification) in, which one or more series or blocks of flat vertical metal flues are
so arranged end on to the axis of the fire place, that the smoke flues for cooling and
carrying off the products of combustion from the fire, are in alternate order and
parallel with the flues for heating the air.
According to the present improvements the fire place is so constructed, and so
separated from the series or blocks of air and smoke flues referred to in the
previous Specification, that the outer sides of the metal walls of the fire place are
directly exposed to the air, so as to form air heating surfaces within the stove
independently of the flat vertical chambers forming the air and smoke flues above
referred to..
Further, two or more series or blocks of the aforesaid flat vertical flues are
arranged one above another in the same vertical plane or one behind another in the
same horizontal plane but with an interval or space between the adjoining series so
that whilst the smoke can pass from the smoke flues of the one series or block to
the other, conduction of heat from the metal plates of the one series to those of the
other is practically avoided whereby the products of combustion in their passage
from the fire to the chimney are more efficiently cooled, and better results as to
economy of fuel are therefore obtained.
The manner in which the invention can be carried into effect will be fully
understood on reference to the accompanying drawings which represent several
forms of stove in which the improvements are in whole or in part embodied.
Figure 1 is a front elevation, Figure 2 a side elevation, Figure 3 a longitudinal
.vertical section (taken on the left side of the fire place through the smoke flues and
on the right side of the fire place through the air flues of the series or blocks of said
flues) and Figure 4 a cross section on the centre line of Figure 3 of one form of the
improved stove.
'
Figure 5 is a cross section on line A B Figure 3 and Figure 6 a plan of the
stove.
1 is the fire place and 22 are the metal bars or ribs forming the side walls of
same, E E are air spaces which according to this invention are provided between
the said side walls and the lower series or blocks of flues. These air spaces admit
a direct current. of fresh air over the metal walls of the fire place which air while
keeping the walls from becoming overheated is itself thereby heated independently
of the extra temperature to which it may be subsequently raised in passing through
the series of vertical air flues above the fire place. 3 is the ash pit, 4 the back
6 6 are loose side tiles as
plate of fire place and 5 the front plate of same.
described in the previous Specification resting on side fire bars for protecting the
metal side walls of the fire place and supplying highly heated air on the top of the
fire place to better complete combustion; 77 are similar plates protecting the
end plates of the fire place; 8-8 are the fire bars; 9 are metal pedestals
supporting the metal walls of the fire place and the air and smoke flues and
forming the sides of the ashpit; 10-10 are outer pedestals supporting the outer
O ends of the air and smoke flues'; 11-11 are the smoke flues; 12-12 are the air

page_text: 1
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flues; 13, 13 are the top series or blocks and 14, 14 the lower series or blocks of
air and smoke flues; 15, 15 are bars supporting the top blocks of the air and
smoke flues off the lower blocks and producing according to my invention a slight
interval or space between them to prevent conduction from the top blocks to the
lower ones; 16, 16 is a smoke passage between the top and lower blocks of smoke
flues; 17 is a door to this smoke passage; 18 is a smoke exit from the smoke flues
to the main smoke ducts F F.which convey the smoke to the smoke box 19 at the
base of the smoke chimney 20 which in this stove is on the top of the casing; the
ducts F.F.pass. over the outer surface of the casing enclosing the end of the stove,
and the upper side of the hot air reservoir or chamber 24 above the stove; the
smoke in thus passing through the ducts F.keeps the reservoir highly heated and
thereby conserves the heat of the air therein. 21 is a door in the casing to get at
the smoke exit 18 for cleaning purposes and 22 is a door to get at the inside
door 17 of the smoke passage 16; 23, 23 are inlets for cold air to the base of the
Fair flues and to the air spaces E E; 25 is an air duct for conveying away the hot
air from the reservoir or chamber 24 to wherever it may be required for heating or
drying purposes. The arrows on the right hand side of Figure 3 indicate the flow
of the current of air which passes up through each of the alternate air flues 12 and
escapes therefrom by the top openings in same. The arrows on the left hand side
of Figure 3 indicate, the flow of the current of the hot gas and products of
combustion from the fire which in their course to the chimney pass through the
other alternate flues 11.
Figures 7, 8 and 9 (in which reference numbers the same as those in Figures 1
to 6 indicate corresponding parts) are respectively a side elevation, a vertical
section, and a half plan and half section on line C D of Figure 8, of a stove of the
same type as that represented in Figures 1 to 6, but with the smoke chimney 20
placed to one side of the stove instead of on top of the hot air chamber 24 over
same, and with the hot air duct 25 on top of the hot air chamber instead of at the
side as in Figures 1 to 6. The products of combustion pass from the vertical
smoke flues into the main smoke duct F on each side of the ashpit of the fire place,
and are conveyed thence by continuation bends 27 to the smoke box 19 forming
the base of the smoke chimney. 26, 26 are cleaning doors of the smoke flues 11;
90 20 are cleaning doors of the flues F F; 29 is a cleaning door at .the
chimney base.
Figures 10, 11, 12 and 13 show modifications of this type of stove, designed to
suit as house or room heating stoves with an open burning fire grate in which coal
or other solid fuel may be used, or the fire grate may be fitted with any suitable
arrangement to burn either oil or gas. In these modifications a series of flat
ver.ical air and smoke flues of the same general construction as hereinbefore
described, are all placed above, and are supported by the metal side walls of the
fire grate, which, being directly exposed to the air, as in the previously described
modifications also form heating surfaces in addition to. the flat vertical air flues
above same.
In the stove shown in Figures 10 and 11 the air and smoke flues lead from front
to rear of the stove, and the air space is behind the fire grate.
.:
Figure 10 is a vertical section through one of the smoke flues and fire grate.
The arrows show how the heated gases pass from the fire place to the chimney...
This figure also shows the main air space E between the metal plates supporting
the air and smoke flues at the rear of the fire grate and metal sides of fire place,
and through which the air in passing keeps the side of the fire place from becoming
overheated, and is itself thereby more or less heated before entering the air flues,
same as in the modifications herein before described.
..
Figure 11 is a front elevation the arrows indicating the direction of the hot air
current issuing from the top of the stove.
In the stove shown in Figures 12 and 13 the flat vertical air and smoke flues are
arranged to extend to right and left across the top of the fireplace, with the air
space E' on each side of the fire-grate.
08

page_text: Figure 12 is a longitudinal section taken on the left of the centre line of
Figure 13 (which is a front elevation) through the air flues, the passage of the air
being indicated by arrows and on the right of the centre line through the smoke
flues, the passage of the heated gases to the chimney being indicated by arrows.
E is the main air space between the metal plates supporting the air and smoke flues
on each side of the fire place and the metal sides of fire place.
It is obvious that any other suitable means can be adopted for producing the
space or interval between the top series 13 and the lower series 14 of the air and
smoke flues but the supporting bars 15 in connection with the upper edge of the
walls 2 as shown answer the purpose well. Further, the two series of air and
smoke flues 13 and 14 instead of being one above the other can be placed one
behind the other, end on to each other, in the same horizontal plane with a space or
interval between them for the purpose above explained.
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. Constructing air heating stoves of the kind or type herein referred to with the
outer sides of the walls of the fireplace directly exposed to the air so as to form
independent air heating surfaces within the stove in addition to those of the flat
vertical chambers forming the air and smoke flues of same, whereby overheating and
consequent wear of the sides of the fireplace are equivalently prevented, substantially
as hereinbefore described.
2. In air heating stoves of the kind or type herein referred to, arranging two or
more series of flat vertical chambers forming the air and smoke flues one above or
behind another in the same vertical or horizontal plane but with an interval
or space between the adjoining series and so that, whilst the smoke can pass from
the smoke flues of one series to those of another, conduction of heat from the metal
plates of the one series to those of the other is avoided or practically 80, whereby a
better cooling of the products of combustion on their way to the chimney and con-
sequent economy of fuel are effected.
3. The several arrangements or combinations of parts forming improved air
heating stoves, substantially as hereinbefore described and represented in the
accompanying drawings.
D-11
ST
1000
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent