Note: Descriptions are shown in the official language in which they were submitted.
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SOLID FUEL STOvE
The present invention relates to solid fuel stoves.
Solid fuel stoves emit a mixture of hot air, solid
particles and volatilised gases to the atmosphere. The latter
two combustion residues contribute to environmental pollution.
It is an object of the present invention to provide a solid
fuel stove in which the amount of environmental pollution
emitted is reduced relative to that emitted by a traditional
stove.
, 10 The present invention provides a solid fuel stove
comprising: (a) a combustion chamber and a door for allowing
access to said chamber, said co~bustion chamber including a
primary combustion chamber having an outlet for smoke and solid
fuel combustion residues and a secondary combustion chamber
which is located downstream of said outlet; (b) combustion
improvement means for heating ambient air and introducing the
heated air into the flow path of the solid fuel combustion
residues to enhance combustion of the residues; and (c) a
baffle disposed between said primary and secondary combustion
- 20 chambers, said baffle being movable between a first position,
in which it restricts said outlet so that in use it restricts
the outflow af the combustion residues and thereby enhances
combustion thereof, and a second position in which said baffle
diverts flow towards said outlet so that in use it deflects the
combustion residues through said outlet, said baffle being
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connected to said door, whereby movement of said door results
in corresponding movement of said baffle so that when said door
; is opened, said baffle is moved relative to said outlet so as
S to prevent the combustion residues escaping from the stove when
the door is open.
Preferably, the combustion improvement means comprises air
,~ ducting which extends from an ambient air inlet, through a
; heating zone in the combustion chamber for heating the ambient
, 10 air, to air outlets into the primary combustion chamber whereby
3 combustion in said primary combustion chamber is enhanced by
the provision of heated combustion air.
Advantageously, the air ducting includes outlets into the
secondary combustion chamber to enhance combustion of residues
in that region.
Conveniently, the secondary combustion chamber is in
thermal communication with the primary combustion chamber below
and thermally insulated above so that in operation a high
temperature prevails.
The invention will now be described more particularly with
reference to the accompanying drawings which show, by way of
example only, one construction of stove according to the
invention. In the drawings:
` Figure 1 is a perspective view of the stove;
Figure 2 is a sectional side elevation of the stove: and
Figure 3 is an enlarged view of a detail of Figure 2.
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Referring to the drawings, and in particular to Figures 1
and 2, the stove comprises the usual conventional components
such as a glass door 1 at the front thereof, a screw adjustable
S a ir i~l et 2 ~Cc~ve the
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glass door l, a primary combustion chamber 3, and an
outlet passageway 4 for combu~tion resldues from the
primary combustion chambex 3, The direction of flow of
- the hot air and residues within the stove is ~ndicated by
arrows.
To reduce the amount of pollution being emitted to
the atmosphere it is desirable that the residues from the
- primary combustion chamber 3 should be subject to as much
combustion as possible. The novel feature~ provided in
10 the stove to achieve additional combustion, and the
operatlon of the stove, will now be described in more
detail.
J ~ot air and combustion residues rise up to the upper
region of the primary combustion chamber 3. A high
temperature prevails ln this upper region, because the
upper reglon is directly above the fire. Furthermore, an
; air ducting system 5 is provided which includes an air
inlet Sa for ambient air and air outlets 5b to the upper
region. Air enter~ the inlet Sa, i5 superheated in the
air ducting system 5, rlses up the air ducting ~ystem 5 by
convective flow, and is emitted through the ports 5b into
the upper region of the prlmary combustion zone.
Introduction of this superheated air enhances combustion.
~y~ The hot air and combustion residues then flow out of
the primary combustion chamber 3 through the restricted
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outlet 6 defined by the fixed plate 7 and the baffle 8.
Because of the restrictive nature of the outlet 6 the
residues spend a longer time in the primary combustion
chamber 3, thereby further enhancing combustion.
The air and combustion residues then enter a
secondary combustion chamber 9, shown on a larger scale in
~igure 3. A high temperature prevails in thi~ secondary
combustion chamber 9 firstly because it is directly over
the fire in the primary combustion chamber 3 and in
0 thermal contact therewith, secondly because the secondary
combustion chamber 9 is very well insulated above by
ceramic wool lining 20, and thirdly because of the
; introduction of heated air from the ducting system through
the nozzle 5b. Further combustion of the residuec takes
place in the secondary combustion chamber 9.
Finally the residues are exhausted to the atmosphere
through the flue 10, shown only in Figure 2.
To add extra fuel the glass door 1 is opened. As the
glass door 1 opens the baffle 8 pivots downwardly ~o that
when the glass door 1 ls fully open the baffle 8 no longer
restricts the outlet 6 from the primary combustion chamber
3 but instead positively deflects combustion residues
through the outlet 6. It will be seen that in this
situation the baffle 8 extends well below the level of the
outlet 6. The purpose of this arrangement is to prevent
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combustion re~idues escaping from the primary combustion
; chamber 3 into the room when the glass door 1 is open.
In order to achieve efficient combustion, the stove
is well insulated. The two side walls are each lined with
S a sheet of ~irebrick (not shown) extending the full height
of the stove. Ceramic wool lining (not shown) i8 also
provided between the flrebrick and the sidewalls,
extending from the bottom of the stove to half the height
thereof.
1G A further desirable feature of the stove, from the
' point of view of cleanliness, is that air entering the
stove through the ad~ustable air inlet 2 passes across the
inside face of the glass door l and thereby keeps the
inside face clean.
A still further desirable feature of the stove, also
from the point of view of cleanlines~, is that a shutter
14 is provided between the primary combustion chamber 3
and the aæh tray 15 and ash box 16. The shutter 14 is
opened from time to time to release accumul~ted ashes from
the prlmary comhustion chamber 3 into the ash tray 15 and
ash box 16, and is then shut again. The ash tray 15 and
ash box 16 are emptied by opening the ash pit door 17 and
withdrawlng the ash tray and ash box. The ash pit door 17
i5 opened, however, only when the shutter 14 is closed and
the ashes have settled in the ash tray 15 and ash box 16.
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In this way there ls less likelihood of loose ashes
blowing about the room. The shutter 14 is operated by
means of a lever (not shown) at one side of the stove.
The stove, including air ducting 5, is made of cast
.~ 5 iron.
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