Field of the Invention
[0001] This invention relates to stoves and, in particular, to gas stoves.
[0002] It is an object of the present invention to provide an improved form of high-efficiency
gas stove, in particular one which is safer and more installation-friendly.
Summary of the Invention
[0003] According to the present invention there is provided a stove, particularly a gas
stove, which includes a housing in the form of a sealed unit in the front part of
which a burner assembly is located, the interior of the housing containing an internal
baffle which is located to the rear of the burner assembly and extends (or includes
a part which extends) downwardly and rearwardly with its lower end spaced from the
rear and the base of the housing, and a flue extending from the housing, the flue
including a first passageway for the discharge of the products of combustion from
that part of the interior of the housing in front of the baffle, and a second passageway
for the supply of air to that part of the interior of the housing to the rear of the
baffle, with the arrangement such that, during operation of the burner assembly, a
flow of air through the second passageway is induced and a balanced flue system is
obtained.
[0004] The inclination of the internal baffle (or of the inclined part of the baffle) to
the vertical is preferably just under 20°, for example, 18°. The dimensions of the
baffle and the housing are preferably such that the spacing of the lower edge of the
baffle from the rear wall of the housing is substantially the same as the spacing
of said lower edge from the base of the housing.
[0005] The baffle may comprise an upper vertical portion and a lower inclined portion, with
the upper portion formed with a substantially centrally located aperture through which
the combustion products enter the first passageway of the flue.
[0006] The flue preferably terminates, at its end remote from the housing, in a flue terminal
or cowl.
[0007] Said first passageway of the flue is preferably a tubular pipe which, between the
housing of the stove and the flue terminal or cowl, is wholly contained within the
second passageway. This arrangement serves to provide a degree of pre-heating of the
fresh air for combustion.
[0008] The burner assembly may be constructed and arranged to operate in the manner described
in British Patent Specification No. 2 310 276, to which reference should be made.
Brief Description of the Drawings
[0009]
Figure 1 is a diagrammatical representation of a gas stove having a rear flue assembly,
Figure 2 is a diagrammatical representation of a gas stove having a top flue assembly,
Figure 3 is a sectional side view of the stove housing of Figure 1,
Figure 4 is a rear view of the stove housing of Figure 1,
Figure 5 is a sectional plan view of the stove housing of Figure 1,
Figure 6 is a sectional side view of the stove housing of Figure 2,
Figure 7 is a rear view of the stove housing of Figure 2,
Figure 8 is a sectional plan view of the stove housing of Figure 2,
Figures 9 and 10 show the internal baffle assembly of the stove of Figure 2,
Figures 9A and 10A show the internal baffle assembly of the stove of Figure 1,
Figures 11 to 14 show the internal baffle for either the stove of Figure 1 or the
stove of Figure 2,
Figures 15 to 17 show the flue cowl of the stove of Figure 1,
Figures 18 and 19 show the flue cowl of the stove of Figure 2,
Figure 20 shows a stove having a further form of cowl,
Figure 21 is a plan view of the cowl shown in Figure 20,
Figure 22 is a side view of the cowl shown in Figure 20,
Figures 23 and 24 show the exhaust of the cowl of Figure 20,
Figures 25 and 26 show a combined back plate and shield forming part of the cowl of
Figure 20, and
Figure 27 shows the cover of the cowl of Figure 20.
Description of the Preferred Embodiments
[0010] Figure 1 shows a balanced flue stove 10 having a rear flue assembly 11, while Figure
2 shows a balanced flue stove 12 having a top flue assembly 13. Each of the stoves
10, 11 has a housing in the form of a sealed unit so that there is no flow of air
from within the room or other space being heated into the interior of the housing
or vice versa. Operation of the stove thus does not cause cold air to be drawn into
the room or other space being heated and does not create draughts.
[0011] As shown in Figure 3, the interior of the stove 10 is divided by a baffle 14 into
a front part (in which the burner assembly is located) and a rear part. The baffle
14 has a configuration as shown in Figures 11 to 13 and is produced by folding a blank
15 having the configuration shown in Figure 14. As shown, the baffle 14 includes an
upper portion 16 which, when the baffle is fitted within the stove 10, extends vertically,
and a lower portion 17 which extends at an inclination of 18° to the vertical. Within
the stove 10, the lower portion 17 of the baffle 14 extends downwardly and rearwardly
from the upper portion 16. The length of the baffle 14 and its location in relation
to the base 18 and the rear wall 19 of the stove 10 are such that the distance between
the lower edge of the baffle 14 and the base 18 is the same as the distance between
the lower edge of the baffle 14 and the rear wall 19.
[0012] The upper portion 16 of the baffle 14 is formed with a generally centrally located
circular aperture 20 to which a cylindrical discharge tube 21 is connected so as to
provide communication between the part of the interior of the housing of the stove
11 in front of the baffle 14 and the central element 22 of the rear flue assembly
11. A burner assembly constructed and arranged to operate as described in Patent Specification
No. 2 310 276 is disposed within the housing of the stove 10 at the position indicated
generally as 23 in Figure 5.
[0013] The rear flue assembly 11 also includes an outer generally tubular element 24, within
which the inner element 22 is contained, with the outer tubular element 24 connected
to a collar 25 which provides communication between the outer tubular element 24 and
the part of the interior of the housing of the stove 10 to the rear of the internal
baffle 14. The rear flue assembly 11 terminates in a cowl 26 constructed as shown
in Figures 15 to 17.
[0014] The cowl 26 comprises a box-like fitting having a horizontal partition 27 formed
with a central circular aperture to which a sleeve 28 is connected so as to provide
communication between the inner tubular element 22 of the rear flue assembly 11 and
the space within the cowl 26 above the partition 27. One side wall of the cowl 26
is solid and fits against the building 29 (as shown in Figure 1), while the other
three walls are formed, above the level of the partition 27, with arrays of apertures
30 through which hot combustion products can exit into the atmosphere. The three walls
of the cowl 26 are also formed with second arrays of apertures 31 which are located
below the level of the partition 27.
[0015] The part of the interior of the cowl 26 beneath the partition 27 and surrounding
the sleeve 28 is connected to a second sleeve 32 which is connected to the outer tubular
element 24 of the rear flue assembly 11. Air from the atmosphere can thus be drawn
into the interior of the cowl 26 below the partition 27 through the apertures 31.
It will then pass along the outer tubular element 24 into the rear portion of the
interior of the stove 10 behind the baffle 14 before flowing under the lower edge
of the baffle 14 so as to be available to the burner assembly.
[0016] In operation of the stove 10, the hot combustion products from the burner assembly
will pass through the inner tubular element 22 for discharge into the atmosphere through
the apertures 30 of the cowl 26. At the same time, air for combustion will be drawn
into the interior of the stove 10 from the atmosphere through the apertures 31 of
the cowl 26. Heat exchange will occur between the hot combustion products and the
air for combustion, thereby providing a pre-heating effect. A high-efficiency, balanced
flue stove is thus provided. Efficient operation of the stove 10 will be obtained
as well as efficient heating of the room or other space in which the stove 10 is located.
[0017] An important advantage of the balanced flue stove is that, as the stove is a sealed
unit, no air is withdrawn from the room in which the stove is located and no combustion
products can enter the room in which the stove is located. This has health and safety
advantages and is of particular benefit to sufferers from chest diseases or respiratory
infections, e.g. sufferers from bronchitis.
[0018] A further advantage of the stove of the present invention is that it is installation-friendly.
No chimney is required and the stove can thus be fitted simply and economically in
a room or other location which is to be heated.
[0019] The stove 12 shown in Figure 2 has a top flue assembly 13 which terminates in a cowl
33 constructed as shown in Figures 18 and 19. It contains an internal baffle assembly
34 constructed as shown in Figures 9 and 10 so as to provide communication between
the part of the interior of the stove 12 in front of the baffle 34 and the inner tubular
element of the top flue assembly 13. The construction and mode of operation of the
strove 12 will be readily apparent from the drawings and from the detailed description
given above of the stove 10.
[0020] Figure 20 shows an arrangement which includes a stove 35 having a lower output that
the stoves 10 and 12 described above. The housing of the stove 35 contains an internal
baffle (not shown) and a burner assembly (also not shown) each constructed and arranged
as described above with reference to stoves 10 and 12. The stove 35 has a rear flue
assembly 36 which includes an outer tubular element 37 and an inner tubular element
38. Air for combustion flows through the outer tubular element 37 into the rear portion
of the stove 35 behind the baffle before flowing under the lower edge of the baffle
so as to be available to the burner assembly. The hot combustion products from the
burner assembly will then pass through the inner tubular element 38 of the rear flue
assembly 36 to a cowl 39.
[0021] The cowl 39 is in the form of a box-like housing having an outer cover 40 (see particularly
Figure 27) produced as a steel fabrication with parts 41, 42, 43, 44, 45 and 46 constituted
by steel gauze so as to allow the free flow of air into the interior of the outer
cover 40. The outer cover 40 is connected to a combined back plate and shield 47 which,
in turn, is connected to the outer tubular element 37 of the rear flue assembly 36.
The cowl 39 also includes an exhaust 48 (see Figures 23 and 24) which is connected
to the inner tubular element 38 of the rear flue assembly 36.
[0022] The exhaust 48 includes a first section 49, an intermediate section 50 and an end
section 51 to which is attached a plate 52 formed with a plurality of apertures 53
so that, in the assembled condition of the cowl 39, air can flow through the apertures
35 into the space within the cowl 39 around the exhaust 48.
[0023] The combined back plate and shield 47 includes a first portion 54 which forms a sold
wall for that side of the cowl 39 adjacent the surface of the wall 55 through which
the flue assembly 36 is arranged to pass. The combined back plate and shield 47 includes
a second portion 56, of cylindrical form, which is attached to the outer tubular element
37 of the flue assembly 36, and a third portion 57 which acts as a wind-shield and
is formed with a drainage hole 58.
[0024] The areas of gauze 41 to 46 allow the free flow of air into the space within the
cowl 39 around the cowl 48, and thence through the cylindrical portion 56 of the combined
backplate and shield 47 into the outer tubular element 37 of the flue assembly 36.
The portion 57 of the combined backplate and shield 47 ensures that, even in severe
gale conditions, the velocity of the air flow through the outer tubular element 37
of the flue assembly 36 will not be such as to "blow out" the flame produced by the
burner assembly.
[0025] In a further embodiment of the invention, not shown in the drawings, the flue assembly
is arranged so that it passes upwardly through an existing chimney of the room in
which it is fitted, rather than passing through a wall. The upper end of the flue
assembly, which will be at about the level of the top of the chimney stack, will then
be provided with a suitable cowl permitting the exit of the hot combustion products
from the flue assembly and the entry of air for combustion into the flue assembly.
1. A stove which includes a housing in the form of a sealed unit in the front part of
which a burner assembly is located, the interior of the housing containing an internal
baffle which is located to the rear of the burner assembly and extends (or includes
a part which extends) downwardly and rearwardly with its lower end spaced from the
rear and the base of the housing, and a flue extending from the housing, the flue
including a first passageway for the discharge of the products of combustion from
that part of the interior of the housing in front of the baffle, and a second passageway
for the supply of air to that part of the interior of the housing to the rear of the
baffle, with the arrangement such that, during operation of the burner assembly, a
flow of air through the second passageway is induced and a balanced flue system is
obtained.
2. A stove as claimed in Claim 1, in which the inclination of the internal baffle (or
of the inclined part of the baffle) to the vertical is just under 20°.
3. A stove as claimed in Claim 2, in which the inclination of the baffle (or of the inclined
part of the baffle) to the vertical is 18°.
4. A stove as claimed in any one of the preceding claims, in which the dimensions of
the baffle and the housing are such that the spacing of the lower edge of the baffle
from the rear wall of the housing is substantially the same as the spacing of said
lower edge from the base of the housing.
5. A stove as claimed in any one of the preceding claims, in which the baffle comprises
an upper vertical portion and a lower inclined portion.
6. A stove as claimed in Claim 5, in which the upper portion of the baffle is formed
with a substantially centrally located aperture through which the combustion products
enter the first passageway of the flue.
7. A stove as claimed in any one of the preceding claims, in which the flue terminates,
at its end remote from the housing in a flue terminal or cowl.
8. A stove as claimed in Claim 7, in which the first passageway of the flue is a tubular
pipe which, between the housing of the stove and the flue terminal or cowl, is wholly
contained within the second passageway of the flue.
9. A gas stove as claimed in Claim 8, in which the flue terminal or cowl comprises a
box-like housing including an outer cover parts of which are formed from steel gauze.
10. A gas stove as claimed in Claim 9, in which a wall of the housing is formed by part
of a combined backplate and shield.