Improvements in Gas and Oil Condensing Stoves.
Year: 1898

page_text: Date of Application, 7th Feb., 1898
Complete Specification Left, 6th Dec., 1898-Accepted, 14th Jan.,
1899
PROVISIONAL SPECIFICATION.
Improvements in Gas and Oil Condensing Stoves.
We, THOMAS FLETCHER and ALEXANDER NEIL, Managing Directors, and FLETCHER,
RUSSELL & Co. LIMITED, all of Thynne Street, Warrington, in the County of Lan-
caster, Gas Apparatus Manufacturers, do hereby declare the nature of this invention
to be as follows:-
Well known types of condensing stoves in which the condensible products of com-
bustion of gaseous and liquid fuels have been separated have had the products of
combustion conveyed through them in ascending and descending tubes.
Our present improvements have been designed with the object of increasing the
power of stoves of this type without increasing their bulk or of adding materially to
their cost. For this purpose we arrange within each condensing tube an additional
air tube concentric therewith thus constituting an annular passage through which
the products of combustion are compelled to pass. Since both the inner and the
outer walls of this passage are exposed to the air, there is necessarily a larger con-
densing effect and it follows that for the same length of tube a larger volume of air
is heated. When the burner is placed immediately below a condensing tube it is
sometimes difficult to arrange the inner air tube open both at the top and bottom.
In such cases we may employ within the body of the condensing tube or the body of
the stove, an intermediate tube closed at the bottom and the inner air tube within
the intermediate tube. The air is introduced through the air tube near to the
bottom of the intermediate tube and flows upwards through the annular space
between the air and intermediate tubes. Various other modifications may also be
adopted.
Improvements in Gas and Oil Condensing Stoves.
We, THOMAS FLETCHER and ALEXANDER NIEL, Managing Directors, and FLETCHER
RUSSELL & Co. LIMITED, all of Thynne Street, Warrington, in the County of
Lancaster, Gas Apparatus Manufacturers, do hereby declare the nature of thie
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
Well known types of condensing stoves in which the condensible products of
combustion of gaseous and liquid fuels have been separated, have had the products
of combustion conveyed through them in ascending and descending tubes.
Our present improvements have been designed with the object of increasing the
power of stoves of this type without increasing their bulk or adding materially to

page_text: their cost.
For this purpose we arrange within each condensing tube an additional
air tube thus constituting an annular or equivalent passage through which the pro-
ducts of combustion are compelled to pa Since both the inner and outer walls of
this passage are exposed to air, there i necessarily a larger cooling surface and a
larger condensing effect, and it follows that for the same length of tube, a larger
volume of air is heated. When the br.ner is placed immediately below a condensing
tube it is sometimes difficult to arrange the inner air tube open both at the top
and at the bottom. In such cases we may employ within the condensing tube or
body of the stove an intermediate ube closed at the bottom, and arrange the inner
air tube within the intermediate tube. The air is introduced through the air tube
near to the bottom of the intermediate tube and flows upwards through the annular
space between the air and intermediate tubes.
The accompanying drawings and the following description thereof will clearly
show how our invention may be carried into practical effect.
Fig. 1 is a vertical section, and Fig. 2 a horizontal section of so much of a con-
densing gas stove as is necessary to illustrate this invention. Fig. 3 shews a modi-
fication hereafter described. :
Figs. 4 and 5 are respec ively vertical and horizontal sections of another form of
stove above referred to, ard hereafter explained.
Referring to Figs. 1 and 2, is the central tube of the stove, from the top of
which the fumes or products of combustion escape, by the passages b, to the con-
densing tubes c, in each of which is arranged the concentric air tude d. This forms
an annular passage inside the tubes c through which the products of combustion
pass downwards to the usual outlet.
Referring to Fig. 3, the central tube a is arranged, as a condensing tube above
the burner x. An air tube or tubes d¹ is or are in such cases arranged therein
serving to cool the fumes as they rise in the tube a.
In some cases above referred to we provide within the central condensing 'tube a'a
concentric air tube e and an intermediate concentric tube f closed at the bottom,
as seen at Figs. 4 and 5.
We form openings or slots near the bottom of the tube e (which is also preferably
closed as shewn) so that the air can enter at the top of the tube e and pass into the
tube (at the bottom thereof), and rise in this tube escaping through suitable
openings at the top thereof. This air will become heated as it rises in f and assist
in cooling the products of combustion as they rise in the annular passage between
the tubes f and a.
The modification necessary to apply this invention to the various forms of con-
densing gas stoves in use will be obvious without further illustration.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we declare that what we
claim is
1. In gas and oil condensing stoves, the combination with a condensing tube of an
internal air tube up which cool air can pass substantially as and for the purposes
berein before described.
2. In gas and oil condensing stoves, the combination with a condensing tube
a ranged above the burner of a concentric air tube and an intermediate tube closed
at the bottom, so that air can pass from the lower end of the air tube to the lower
end of the intermediate tube and rise upwards in the latter as and for the purposes
herein before described.
Dated this Jan
T
1000
GEO. DAVIES & Co.,
Agents for the Applicants, 4, St. Ann's Square, Manchester,