Note: Descriptions are shown in the official language in which they were submitted.
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HEATER
lrhis invention relates to heaters and refers
particularly, though not exclusively, to heaters for the
burning of combustible fuels such as, for example, wood and
briquettes.
It is the principal object of the present invention
to provide a heater whereby the combustion of the fuel is
maximised, and the heat generated thereby is also used to the
maximum extent.
With the above and other objects in mind, the
present invention provides a heater having a fire box; said
fire box having a front wall, a rear wall, two parallel side
walls, a top and a base, a door in said front wall, a primary
air inlet to said fire box above said door, a secondary air
inlet to said fire box in said rear wall, and a tertiary air
inlet to said fire box, said heater also having a second skin
over said fire box so that air passes in a gap between said
second skin and said fire box before passing through said
secondary air inlet and said tertiary air inlet.
In order that the invention may be better understood
there shall now be described a preferred construction of a
heater incorporating the preferred features of the present
invention, the description being by way of non-limitative
example and with reference to the accompanying illustrative
drawings. In the drawings:
Figure 1 is a front perspective view of the heater;
Figure 2 is a vertical cross-sectional view along
the longitudinal axis of the heater of Figure 1;
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Figure 3 is a full vertical cross-sectional view
along the lines of and in the direction of arrows 3-3 of
Figure 2; and
Figure 4 is a full vertical cross-sectional view
along the lines of and in the direction of arrows 4-4 of
Figure 2.
The heater illustrated comprises a heater 10, a
chimney or flue 12, a pedestal 14 and a base 16.
The heater 10 is a cuboid and has a front 18, rear
20, and two sides 22. The front 18 has an opening 24 closable
by a door 26. The door 26 has a peripheral frame 28 which has
one side hingedly connected to the front 18 adjacent the
opening 24, and the other side provided with a handle 30,
which also allows the door 26 to be locked shut. A
transparent panel 32 mounted in an insulating seal 34
completes the door 26.
The rear 20 and the two sides 22 of the heater 10,
as well as part of the front 18 are made with a double skin.
There is an interior skin generally designated as 36 which
constitutes a fire box and a second skin 38 comprising the
front 18, rear 20 and two sides 22. The fire box 36 has a top
40, a rear wall 42, sides 44, bottom 46 and front sections 48.
In front 18 below door 26 there are a plurality of
openings 50 which have a slider control 52 so that the area of
the openings 50 can be varied so as to control the rate of
primary airflow into the heater 10. The air passes through
the openings 50 and into the space between front 18 and the
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front 48 of ~he fire box 36. It passes up the space on either
side of opening 24 to the space above the opening 24. There
it can enter the fire box 36 through an access opening 54
immediately above and adjacent door 26. A deflector plate 56
deflects the air towards door 26. From the time the air
enters openings 50 to the time it passes through the access
opening 54 the air is continually heated by the front wall 48
of fire box 36. The air also helps to cool front 18.
As the air passes down the inside of panel 32 it
heats further, also helping to cool panel 32. A lower
deflector plate 58 deflects the air towards bottom 46 of fire
box 36. There may be provided a grate 60 on bottom 46 and
which holds the burning material. The air off the lower
deflector plate 58 then passes through to and is consumed in
the combustion of the material in the grate 60.
When most material burns, gases are given off.
These gases are, in the main, combustible. However, there is
normally no means for igniting these gases. To utilise the
potential heat in these unburnt gases the present invention
provides secondary and tertiary air induction so as to cause
secondary and tertiary combustion.
To do this, the base 16 has an opening 62
therethrough to allow air to enter the hollow interior 64 of
pedestal 14. An electric fan 66 may be provided to assist in
the air flow. The fan 66 is preferably mounted on a plate 68
hingedly connected to lower plate 70 at the rear thereof. The
plate 68 is connected to a control rod 72 which passes through
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an L-shaped opening 74 in the front 76 of the pedestal 14.
When the rod 72 is in the position shown in Figure 1, the fan
66 is in the position shown in Figure 2. However, if the rod
72 is moved to the lowermost point 78 of opening 7~, the fan
66 is lowered so as to allow greater air flow due to natural
convection.
The air passes into the space between lower plate 70
and the bottom 46 of the fire box 36. From there it can
travel up the space between the sides 22 and the sides of fire
box 36, all the time being heated. One possible course for
the air is to travel to and pass over the top 40 fire box 36
and out through lowexed openings 80 in front 18. This air has
been heated and has also assisted in cooling the sides 22 and
top 82 of heater 10.
Another route followed by the air entering through
pedestal 14 is up between rear 20 and the rear wall 42 of fire
box 36. This air would also be heated as it rises and would
also pass over top 40 of fire box 36 and out through lowered
openings 80, thus helping cool the rear 42 and top 82.
To allow for a secondary air Lnlet into fire box 36,
two riser tubes 84 are provided and which allow air to enter
through the lower space 860 As the air rises through the
riser tubes 84 it is heated. The air then enters a secondarY
manifold 88 extending the full width of rear ~2 of fire box
36. The manifold 88 has a plurality of openings 90 along its
length. Heated air flows through the openings 90 into the
fire box 36 to mix with the unburnt gases, thus providing the
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necessary oxygen input to allow the unburnt gases to ignite
and burn. This increases the heat output of the heater 10. A
secondary deflection plate 92 is provided to prevent the
openings sooting-up, and to deflect the flow of unburnt gases
past the air inlet stream.
There is also provided a hollow baffle 94 open at
the rear 96 to enable air to enter the interior 98 of baffle
94 from the rear space 100. Thé baffle 94 is also open at
each side 102 so that air can also enter the interior 98 of
baffle 94 from the side space 104. The air entry helps to
cool the baffle 94, particularly the lower plate 106. As
baffles in fire boxes tend to have a short life-span, this
flow of cooling air increases the life-span of the baffle g4.
The baffle 94 has a front 108 having a plurality of
holes 110 therein. These holes 110 allow heated air to pass
through in the manner shown in Figure 2 to mix with any
unburnt gases to cause final or tertiary combustion.
This should complete the combustion of all unburnt
gases, if the heater is operating effectively. The remaining
gases and the smoke pass up through the flue 12 by means of a
hole 112 in top 40.
Preferably, the openings 50 in front 18 are not all
circular so that as the slider control 52 moves across the
changa in the area open is linear to provide for more accurate
control. Also, this can allow proper ~alance of air flow so
that it is not all through one side but evenly, to assist with
an even burning.
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Also, an outer skin 114 may be provided over the
sides 22, rear 20 and top 82 so that contact by a person would
not cause burning, The outer skin 114 is spaced from the
sides 22,-rear 20 and top 82 to allow an air gap 116. This
air gap 116 is open at the bottom 118 to enable air to pass up
through the gap 116 and out through lowered openings 120 in
the top 122 of the outer skin 114. This air would be heated
by rear 20, sides 22 and top 82, and would also keep the outer
skin 114 cool.
The sides 44 and top 40 may be provided with air
baffles 124 to control and direct the air flow so that an even
air flow and heating of the air can result.
Whilst there has been described in the foregoing
description a heater incorporating the preferred features of
the present invention, it will be understood by those skilled
in the technology concerned that many variations or
modifications in details of design or construction may be made
without departing from the present invention, the scope of
which is to be determined from the foregoing description.
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