Improvements in Gas Stoves.
Year: 1895

page_text: Date of Application, 11th June, 1895
Complete Specification Left, 11th Mar., 1896-Accepted, 11th Apr., 1898
Improvements in Gas Stoves.
We ROBERT MORTON, Gentleman, of 64 Hamilton Terrace, London, N.W.
and ROBERT PRINGLE, M.D. of 11 Eliot Park, Blackheath, London, S.E. do
hereby declare the nature of this invention to be as follows :-
This invention has for its object to provide a regenerative gas stove of simple
and economical construction, in which ordinary burners such as are commonly
employed for illuminating may be used for heating or illuminating purposes,
without the highly deleterious effects which the employment of such burners for
heating or illuminating purposes at present entails.
This object is attained by utilizing the hot products of combustion in order to
raise to a high temperature both the gas and air supplies before these meet at the
point of ignition, so that the process of combustion may be thoroughly completed
in the flame, and that consequently neither shali any soot be deposited within
the stove itself, nor shall any of the constituents of the gas be allowed to escape
from the stove in an unconsumed state.
The method of heating the air supply is as follows:--From apertures formed in
a tube plate spanning the upper part of the stove casing, a series of vertical tubes,
open at both ends, are suspended one over each burner or small group of burners,
the lower end of each tube terminating at or near the level of the burners, these
tubes thus forming flues to receive and carry off the ascending hot products of
combustion.
A short distance below the tube plate above described, another tube plate also
spans the stove casing. Each of the apertures necessarily formed in this second
and lower plate to admit of the flue tubes just described passing through it, is
made large enough to accommodate an outer vertical tube or sleeve which is
suspended from the lower tube plate so as to enclose one of the flue tubes and
at the same time to leave an annulus or space between that inner tube and the
outer sleeve, the lower end of each sleeve opening slightly below the lower end
of the flue tube within it.
The annulus above mentioned forms a chanuel for the inflowing current of fresh
air, which, by contact with the inner flue tube, is raised to a high temperature in
its downward passage from the upper chamber enclosed between the two tube
plates; whilst further in order that no air shall pass to the burners excepting
through the annulus, the bottom of the stove casing is closed by a diaphragm
below the level of the burners.
The supply of fresh air to the upper chamber enclosed between the two tube
plates is maintained through a series of vertical tubes placed between the tubes
already described, and connecting openings in the lower tube plate with corre-
sponding inlet openings in the bottom diaphragm which is raised a sufficient
distance above the ground by the feet of the stove. It will thus be seen that
the fresh outer air, in order to reach the burners, must first pass through the
openings in the bottom diaphragm upwards by way of the tubes connected to
those openings to the upper chamber between the tube plates, thence downwards
through the annuli surrounding the flue tubes, to the point of ignition. It will
also be obvious that the temperature of the inflowing fresh air is materially raised,
not merely in the downward passage through the annuli, but also in the upper
chamber and in the tubes which supply the latter.

page_text: The heating of the incoming supply of gas is effected by allowing the hot
products of combustion from one or more of the burners to impinge upon a
heating chamber forming an enlargement upon the supply pipe, which is arranged
to descend vertically through one of the above described flue tubes (preferably a
central one) made wider for the purpose, the burners being fed through branches
led off radially just above the bottom diaphragm of the stove casing. The gas
supply pipe may enter the stove casing in the first instance either at the top or
bottom of the latter but preferably at bottom in which case the pipe must obviously
be first led upwards and bent over so as to be capable of descending through the
enlarged heating chamber as described.
In
The top of the stove casing is formed by a removable cover raised a short
distance above the upper tube plate, the discharge of the products of combustion
taking place through peripheral openings between the tube plate and cover.
order that the said discharge may, when required, be directed downwards, a
deflecting plate, reversible or removable at will, is arranged to rest upon the
cover, its edges projecting some distance beyond the sides of the stove casing
and being dished so as when turned downwards to direct the current escaping
'through the peripheral openings above described. Openings for the reception of
cooking utensils, and furnished with removable lids in the usual manner, may be
provided in the cover and deflecting plate. Close fitting doors are provided in the
sides of the stove casing opposite to the burners so as to give access to the
latter for lighting or renewal. For the purpose of transmitting light, these
doors are fitted with transparent material.
Gills or vertical channels, open top and bottom may be attached to the outside
of the casing between the doors, in order by becoming heated, to ensure a inore
thorough circulation of the atmosphere in the immediate neighbourhood of
the stove.
The above described stove is intended to be ordinarily constructed of sheet
metal, but any portion of it may be composed of, or lined with, suitable refractory
material, such as fireclay.
In order to further adapt the apparatus for illuminating purposes, one or more
of the radial branches of the gas supply pipe may extend through apertures in the
stove casing and be provided with a burner of any approved construction.
Dated this 11th day of June 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
We, ROBERT MORTON, Gentleman, of 64, Hamilton Terrace, London, N.W.
and ROBERT PRINGLE M.D. of 11, Eliot Park, Blackheath, London, S.E. 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 of an improved gas stove of simple and inexpensive
construction, whereby absolutely complete combustion of the constituents of coal
gas is obtained by the use of ordinary (or non-atmospheric) burners, producing
clear bright luminiferous flammes which do not impinge upon any part of the stove
it being only to the currents of heated air generated by the combustion that the
metallic surfaces of the stove are exposed. The attainment of perfect combustion
is ensured by so proportioning the gas and air supplies that the process of combustion
shall be thoroughly completed in the flame, and by utilizing part of the heat of
combustion to gradually raise to the necessary temperature both the gas to be

page_text: consumed and the air admitted to support combustion before the gas and air meet
at the point of ignition, so that they are so to speak prepared for the complete
oxidation.
There is therefore no reduction of the heat of the flames either by contact with
cooling surfaces or by the inrush of either cool air or gas, and the conditions are
such as to be eminently calculated to ensure perfectly complete combustion of the
constituents of the gas and avoid the highly deleterious effects produced by the
combustion of gas in ordinary non-atmospheric burners. There is consequently no
deposit of soot within the stove itself, nor the possibility of any of the constituents
of the gas escaping in an unconsumed or partially consumed state, so that the
combustion of coal gas in this stove is unaccompanied by any objectionable smell.
The injurious gases acetylene, carbonic oxide, and sulphuretted hydrogen, which
result from incomplete combustion are entirely absent, the only products escaping
being those which are the inevitable result of complete combustion, namely watery
vapour and carbonic acid which are hygienically quite innocuous if the apartment
in which the stove is placed is provided with ordinary means of ventilation.
The improved construction of gas stove is illustrated in the accompanying
drawings forming part of this Specification wherein
Figures 1 to 5 represent a stove of circular form having tubes symmetrically
disposed around a central burner; and
Figures 6 and 7 shew a stove of square form in which the tubes are fewer
and differently arranged;
Figure 1 represents a vertical sectional elevation of the circular stove taken on
line 1-1 Figure 5.
Figure 2 is an external elevation and Figures 3 4 5 are horizontal sections
respectively taken on lines 3-3, 4-4, 5-5, Figure 1.
Figure 6 is a vertical section and Figure 7 a horizontal section of the square
stove.
The same letters of reference indicate the same parts in all the figures.
Referring first to Figures 1 to 5, A is the casing of the stove made of sheet
metal of cylindrical, oval, or other shape in cross section, in which are fixed
horizontal diaphragms or tube-plates BC D. Vertical flue tubes E preferably
made of fireclay and open at both ends are suspended by their upper ends in
apertures in the top tube plate B, the lower end of each tube terminating above
the level of the burners, these tubes being preferably equally spaced around a
central similar tube and forming with the central tube upcast flues to receive the
ascending current of hot air and products of combustion. Below the tube plate B
is another tube plate C apertured to carry the tubes F which give passage to the
flue tubes E and form downcast flues for the admission of the inflowing heated
current of fresh air. The bottom of the stove casing is closed by the lowermost
diaphragm D below the level of the burners so that no direct access of cold air to
the burners is possible. Vertical tubes G of sheet metal arranged alternately with
the tubes already described are fixed in apertures in the tube plate C and in corre-
sponding openings in the bottom plate D which is raised by the feet of the stove a
sufficient distance above the ground to permit fresh air to pass up through the
tubes G to the chamber H enclosed between plates B and C, the temperature of
the inflowing fresh air being raised in ascending through the tubes G in the upper
chamber H and by contact with the highly heated Hues E.
In one of the flues E, preferably the central one of the series, is placed a gas
heating chamber I forming an enlargement of the gas supply pipe J which descends
vertically through that flue, the burners jj being placed on radial branches J¹ just
above the bottom diaphragm D of the stove casing, the gas supply pipe entering
the stove casing either at the top or bottom but preferably at bottom as shewn,
in which case the pipe is preferably first led upwards through the bottom
5 plate D within the casing A between the tubes and through and over the
top tube plate B to the central flue E in which it is connected to the heating
chamber as described. The burners j are respectively placed each centrally

page_text: beneath one of the flue tubes E whilst the burners are preferably place:
not immediately below the central flue E in which the gas heating vessel I is
placed, but beneath a sheet metal funnel-shaped deflector projecting downwards
from the central flue E as shewn so that not only can the flames not impinge
directly on the gas pipe and heating vessel but are at such distance therefrom
that the heat of the ascending current through the central flue is moderated so that
whilst the gas is sufficiently heated to avoid cooling the flame and ensure perfect
combustion under the conditions described overheating of the gas which would
have the effect of causing a deposit of carbon in the heating vessel and the
impoverishment of the gas to the detriment of the heating power of the flames,
is practically avoided, although provision is made by plugs ii at top and bottom
for cleaning out the heating vessel in case of any accidental deposit therein. The
absence of this troublesome deposit of carbon in the gas heating vessel in normal
working is a feature distinguishing this improved stove from all others in which the
preliminary heating, or rather overheating, of the gas has been attempted. The
tubes and other parts of the stove are so proportioned, and the consumption of gas
and air so adjusted, that the flames burn with a pure white light and perfect
steadiness and thereby afford a means of ascertaining the proper working condition
of the stove. The quantity of gas consumed is very small. The other flues E
may also have similar downwardly projecting funnel-shaped prolongations as
indicated in dotted lines and the burners j' may be of the smallest size used for
lighting purposes, the size of the burners beneath the flues E depending on the
size of the stove and the amount of air supplied for combustion. For a consumption
of 20 cubic feet of gas per hour the air inlet tubes G should have an aggregate
area of approximately 50 square inches and a height of about 18 inches. After the
siove has been thoroughly heated the gas supply may be so diminished as to lower
the flames below the normal capacity of the burners.
The top K fits removably in the sides of the stove casing and is a short distance
above the top tube plate B the products of combustion being discharged through
side openings in the flange of the cover. In order that the discharge may when
required be directed downwards a deflecting plate L reversible or removable at will
is placed upon the cover its inclined marginal portion projecting some distance
beyond the sides of the stove casing so as to direct downwards the current escaping
through the openings k. Openings for the reception of cooking utensils and
furnished with removable lids in the usual manner, may be provided in the cover
and deflecting plate. Close fitting doors M are fitted on the sides of the stove
casing over apertures opposite to the burners so as to give access to the latter for
lighting or renewal. For lighting purposes these doors are apertured and fitted
with transparent material. External gills, in the form of vertical channels O,
open at top and bottom, may be attached to the outside of the casing in order to
ensure a more thorough circulation of the atmosphere in the immediate neighbour-
hood of the stove. These channels are preferably of U-section with lateral flanges
either fitting in grooves provided on the casing so as to be removable at will or
permanently fixed.
The sheet metal may if desired be lined with refractory material such as fireclay.
If it be desired to use the beated gas for illuminating or cooking purposes at another
part of the apartment, a gas pipe N may be led off from beneath the stove to the
point where the gas is to be consumed.
A small stove of oval or flattened section may comprise merely the central flue E
enclosing the gas heater and surrounded by its downcast annulus with an upcast air
tube at either side, the construction and operation otherwise remaining the same.
Referring now to Figures 6 and 7, the parts indicated by the same reference
letters as in the other figures fulfil the same functions although the form and
arrangement are somewhat different. There is but one upcast flue E shewn,
although there might be two or more arranged side by side, whilst the downcast air
passage is rectangular in form and surrounds on three sides only and at a distance
the flue E, the air being heated by direct contact with the upper part of the flue E

page_text: in the chamber H as in the other arrangement and by radiation from the lower
part of the flue and the passage F opening so far below the level of the lower end
of the upcast fiue E as to enable deflectors such as those before described, to be
dispensed with.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. The herein described arrangements of gas stove constructed with flues and
chambers as described whereby to cause the incoming air and likewise the gas to
be gradually heated before reaching the burners substantially as specified.
2. A gas stove constructed of a casing enclosing upcast flues of refractory
material suspended in a tube plate forming the top of an air heating chamber,
downcast air tubes suspended in a second tube plate forming the bottom of the air
heating chamber, upcast air tubes fixed in and opening through the bottom of said
chamber and the bottom of the stove casing, burners arranged as described in the
space below the suspended upcast flues and connected with a gas heating chamber
contained in one of the upcast flues substantially as specified.
Dated this 11th day of March 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.