Year: 1885

page_text: I GEORGE PORTER, of N° 23, Cullum Street, in the city of London, Engineer
do hereby declare the nature of this invention to be as follows:-
This invention consists in a novel construction of hot air stoves whereby the
heating power is greatly increased and the consumption of gas, oil or other fuel
considerably decreased.
Notwithstanding the great heat given off by this stove it does not require a flue
or vent pipe, practically every particle of heat being utilized in its passage
through the chambers of the stove the products reaching the lower chamber
perfectly cold and in a liquid state consequently there are no objectionable gases
passing into the apartment.
In carrying out my invention I construct the stove of number of concentric
tubes or cylinders so as to form vertical chambers, through the interior of which
the heated products of the gas, oil or other fuel pass; the exterior of the said
chambers form passages for pure air to pass through (these passages are sometimes
connected with transverse tubes); the air in its course impinges upon the heated
sides of the chambers and thus causes to be emitted from the stove a continuous
stream of hot air.
The first chamber is formed of two tubes or cylinders placed one within the other
the space between the cylinders being sealed at both ends thus forming a double
cylinder with a central passage through it; the space between the cylinders I term
the heating chamber, heat being given off from the surfaces of the central passage
as well as the exterior surface of the cylinder-I attach great importance to this
central tube because it acts as a deflector of the heat upon the outer tube which
being a large surface affords greater heat than any other part of the stove; the
outer tube acts also as a deflector of heat upon the central tube. Where this central
tube is not used it would be necessary in order to obtain good results to employ
some other kind of deflector either vertical or horizontal. At the bottom end of the
chamber the heat is generated and when gas or oil is employed I use by preference
flat flame burners, but the circular or argand form of burnér may also be used.
burner is mounted preferably in a funnel shaped box having a perforated bottom
or sides which I term a generating chamber and is fixed to the bottom end of the
heating chamber. The funnel or upper part of the generating chamber passes a
short distance up into the heating chamber the remainder projecting below it for
The

page_text: facility of lighting the burner, for reflecting light and also to effect the essential
result of giving off heat at a level near to the floor line but the generating
chamber may be fixed entirely within the heating chamber. From the upper end
of the heating chamber a tube or tubes is or are taken and connected to another
chamber or chambers similar in construction to the heating chamber but which I
term a cooling chamber and which is fixed within the central passage of the
heating chamber leaving an air space all round; in this air space is placed a tube
for the purpose of splitting the air current and shielding the cooling chamber from
the heat given off by the heating chamber. To the bottom of the cooling chamber
is fitted a box or trough in which the products of combustion are collected in a
liquid state. The cooling chambers may be placed outside the heating chamber
instead of being placed in the central passage, in that case the heating chamber
could be made drum shaped without a central passage or tubes through it, but it
would not be so effective as a considerable amount of heating surface would be lost..
In order to obtain still further heat from the stove an air chamber or chambers
is or are formed around the outside of the heating chamber; this may be effected
by a cylinder being fixed so as to allow a current of air to pass up between it and
the heating chamber. But in order to obtain hot air in greater quantities and at a
higher temperature I have discovered that it is necessary that the inner side of the
cylinder should be partially in contact with the heating chamber in order that the
heat may be conveyed from one to the other by means of radiation which thus
considerably increases the power of the heating chambers. This may be effected
by means of ribs or by a number of tubes placed round the heating chamber but I
have found it most advantageous to corrugate a sheet of iron or other metal the
projecting parts of which when the sheet is fixed round the heating chamber form
a series of tubes in themselves and the other parts which touch form radiators.
Another important feature of this outer casing is the prevention of accidents from
fire as there is no possibility of ignition in case of anything coming in contact with
the stove....
I sometimes connect the lower parts of the air chambers with a tube so that it
may be connected to a tube brought from the outer atmosphere; by this means
the apartment is supplied with a continuous stream of fresh hot air.
It will be obvious that my improved stove can also be made with a flue or venț
pipe without detracting from its heating or economical powers; this is effected by
the removal of the condensing box at the bottom and of a shield in one of the air
chambers by which means the products of combustion are re-heated in passing the
lower part of the stove and thereby enter the flue or chimney in a heated state.
Dated the 8th day of December 1885.

page_text: I, GEORGE PORTER of N° 23 Cullum Street in the City of London, Engineer,
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 consists in a novel construction of hot air stoves whereby the
heating power is greatly increased and the consumption of gas, oil or other fuel
considerably decreased.
•
Notwithstanding the great heat given off by this stove it does not require a flue
or vent pipe, practically every particle of heat being utilized in its passage through
the chambers of the stove the products reaching the lower chamber perfectly cold
and in a liquid state, consequently there are no objectionable gases passing into
the apartment.
In carrying out my invention I construct the stove of a number of concentric
tubes or cylinders hereinafter more particularly described so as to form vertical
chambers, through the interior of which the heated products of the gas, oil, or other
fuel pass to a box or trough or to the outside of the stove; the exterior of the said
chambers form passages for pure air to pass through, these passages being sometimes
connected with transverse tubes; the air is admitted at the lower part of the stove
which is left open and in its course impinges upon the heated sides of the chambers
and thus causes to be emitted from the top of the stove a continuous stream of
hot air.
In order to enable my invention to be fully understood I will describe the same
by reference to the accompanying drawing, in which figure 1 represents a vertical
section of a hot air stove constructed according to my invention; Figures 2 and 3
represent horizontal sections on the lines A B and C D respectively of figure 1.
Figures 4 and 5 represent an elevation and plan respectively of a modified form
of part of the stove shewn in figures 1, 2, and 3; figures 6 and 8 are similar views
to figure 1 but shewing slight modifications in the construction of my stove and
figure 7 is a horizontal section on the line EF of figure 6. Similar letters of
reference indicate similar or corresponding parts throughout the several figures
of the drawing.
'I will first describe my invention by reference to figures 1, 2, and 3. a represents
one of the vertical chambers of the stove which chamber is formed of two tubes or
cylinders b and c, the tube b being placed within the other tube c; the space
between the said tubes is sealed at both ends d and e tirus forming a double
cylinder with a central passage f through it; the said space or chamber a between
the cylinders b and c I term the heating chamber, heat being given off from the
surfaces of the central passage f as well as the exterior surface of the cylinder c.
I attach great importance to the central tube b because it acts as a deflector of the
heat upon the outer tube c which being a large surface affords greater heat than
any other part of the stove; the outer tube c acts also as a deflector of heat upon
the central tube b. (Where the central tube b is not used it would be necessary in
order to obtain good results to employ some other kind of deflector either vertical

page_text: or horizontal). At the bottom end d of the chamber a the heat is generated and
when gas or oil is employed I use by preference flat flame burners, but the circular
or Argand form of burner or a Bunsen burner may also be used. gg are the
burners two of which are shewn but I do not confine myself to this number.―
Each of the said burners is mounted in a box or chamber h having a perforated
bottom or sides which box I term a generating chamber, it is fixed to the bottom
end of the heating chamber a. The upper part h', of each of the generating
chambers passes a short distance up into the heating chamber a, as shewn in
figure 1, the remainder projecting below it and having an opening h³ for facility
of lighting the burner and for reflecting light; the said arrangement of the
generating chambers also effects the essential result of giving off heat at a level
near to the floor line. The generating chambers h, h, however may be fixed
entirely within the heating chamber a. From the upper end of the heating
chamber a, pass two (or one or more) tubes a¹, which are connected to another
of the vertical chambers herein before referred to marked i in the drawing (or other
chambers) similar in construction to the heating chamber a, that is to say, formed
of an inner and an outer tube and 2 respectively. The chamber i, I term a
cooling chamber; it is fixed within the central passage f of the heating chamber a
leaving an air space all round; the air enters the passage f from the lower part
of the stove which is open at A, and leaves the stove by passing through the
perforated top or cover p into the room or chamber to be heated; in the air
space is placed a tube or shield j, for the purpose of splitting the air current and
thereby shielding the cooling chamber i, from the heat given off by the heating
chamber a. To the bottom of the cooling chamber is fitted a box or trough k, in
which the products of combustion are collected in a liquid state and discharged
through a pipe into a pan k¹.
The box or trough is formed in two parts k¹ and k² connected together by
tubes l, and having a number of air tubes m and n passing through the said
parts and for the circulation of air so as to cool the said box k as much as
possible.
In order to obtain still further heat from the stove an air chamber or chambers
is or are formed around the outside of the heating chamber a; this may be effected
by a cylinder being fixed so as to allow a current of air to pass up between it and
the heating chamber. But in order to obtain hot air in greater quantities and at
a higher temperature, I have discovered that it is necessary that the inner side of
the cylinder should be partially in contact with the heating chamber in order that
the heat may be conveyed from one to the other by means of conduction which
thus considerably increases the heating power of the stove. This may be effected
by means of ribs or by a number of tubes placed round the heating chamber but
I have found it most advantageous to corrugate a sheet of iron or other metal as
shewn in the drawing at figure 2, the projecting parts o' of which corrugated sheet
when the sheet is fixed round the heating chamber a, as shewn form a series of
tubes o² in themselves and the other parts o³ which touch the tube c of the heating
chamber a form conductors. Another important feature of this outer casing is the
prevention of accidents from fire as there is no possibility of ignition in case of
anything coming in contact with the stove.
The arrows on the drawing indicate the course of the heated air and of the
products of combustion through the stove.
In order to further heat the air passing through the stove before it is passed
through the perforated top or cover p into the room or the like, I find it advan-
tageous to place within the heating chamber a (as shewn in figures 1 and 3) a
chamber or super-heater q of similar construction to the said chamber a, that is to
say, formed by an inner and an outer tube q' and q³ the space between the two
tubes being sealed at the ends q³. This chamber q I connect to the end e of the
heating chamber a, by means of two (or more) air ways r. By this construction
the heated air or a portion of the same at the top of the stove will be caused to
pass down through one of the air ways r, and circulate through the chamber q,

page_text: thereby receiving additional heat and will pass away up through the other
airway r, into the top of the stove.
Instead of forming the super-heater or chamber q, as just described I may form
it as shewn in elevation and plan respectively at figures 4 and 5, the super-heater
being formed seginental in plan so that by forming an opening in the end e of the
heating chamber a, the said superheater can be dropped into the said chamber and
held in position by its flange s resting on the end e of the chamber a.
I provide a partition s¹ which reaches almost to the bottom of the superheater
thereby leaving a small space for the circulation of air as shewn by the arrow in
Figure 4; more than one of this form of super-heater can be used, if required, as
will be obvious.
I sometimes connect the lower part of the air chamber a, with a tube t (as shown
in dotted lines in figure 1) brought from the outer atmosphere, in which case
I prevent the admission of air at the lower part of the stove by means of a plate t¹,
also shewn in dotted lines; by this means the apartment is supplied with a
continuous stream of fresh hot air.
In some cases as shewn in figures 6 and 7 the cooling chamber or chambers can
be placed outside the heating chamber a, instead of being placed in the central
passage fas berein before described and shewn in figures 1, 2 and 3.
In figures 6 and 7 two cooling chambers i, are shewn, one on each side of the.
heating chamber a. The heating chamber a, could in this case be made drum-
shaped without a central passage f, but it would not be so effective, as a consider-
able amount of heating surface would be lost, or instead of providing the beating
chamber a with a single central air passage f, several air passages may be placed
therein.
It will be obvious that my improved stove can also be made with a flue or vent
pipe u, as shewn in figure 8 without detracting from its heating or economical
powers; this is effected by the removal of the condensing box k, at the bottom of the
stove and of the shield j, in the passage or chamber f, by which means the products
of combustion are re-heated in passing the lower part of the stove and thereby
enter the flue or chimney u, in a heated state so as to cause the required draught
to carry off the said products.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In a hot air stove the employment of a number of concentric tubes or
cylinders arranged substantially as herein described and represented so as to form
vertical chambers through which pass the heated products of combustion the
exterior of the said chambers forming passages for the air to be heated by the
stove and supplied to the apartment as herein set forth.
2. The combination of parts forming the improved hot air stoves substantially
as hereinbefore described and represented in the various figures of the accompanying
drawing.