IMPROVEMENTS IN GAS-STOVES
Year: 1879

page_text: LETTERS PATENT to James Adams, of Glasgow, in the County of Lanark,
North Britain, Doctor of Medicine, for the Invention of "IMPROVEMENTS IN
GAS-STOVES."
Sealed the 29th August 1879, and dated the 19th March 1879.
PROVISIONAL SPECIFICATION left by the said James Adams at the Office of
the Commissioners of Patents on the 19th March 1879.
JAMES ADAMS, of Glasgow, in the County of Lanark, North Britain, Doctor
of Medicine. "IMPROVEMENTS IN GAS-STOVES."
This said Invention relates to certain novel improvements in the construction
and arrangement or combination of the parts of a gas stove, capable of various
modifications for different purposes, and its action for heating the dwelling and
other apartments of houses and other buildings, or for other general or special
heating or ventilating, and it may be for cooking purposes, by the burning of coal
gases or other hydrocarbon gases. The improvements in the construction and
effect of this stove (made in accordance with this Invention) are such that it is far
more perfect in its action and use, conformably with the scientific laws of the
perfect combustion of the gases, for producing and utilizing the greatest possible
amount of heat therefrom, and for the more perfect ventilation of the gases and
heated air or currents in and to or from the stove in the apartment more con-
sistently with the best sanitary laws of health than with or by any of the stoves
heretofore in use.
The purposes or objects and advantages of the Invention or improvements are
that the waste products of combustion are not permitted to mix with or vitiate the
atmosphere of the apartment that is heated, but are conveyed away by special
conducting ducts, flues, and pipes, the sides and surfaces of which receive and con-
duct or radiate the heat through them to the air entering the apartment. The hot
gases generated within the stove are not permitted to escape quickly as in all
other previous gas stoves, but are detained within the stove until they have
imparted all their practically effective heat to the apparatus and cold air of the
apartment. The hot gases generated within the stove are not diluted or cooled
down and robbed of their heat, as in all previous stoves, by the admission of
needlessly great quantities or currents of atmospheric air. Only such a carefully

page_text: regulated supply of air is admitted into the combustion part or chamber of the
stove as science has shown to be essential for the complete combustion of the gas,
and as numerous special experiments have demonstrated to be necessary for the
escape of the gases and the due ventilation of the stove itself. The pure air which
is heated by the stove is not unpleasantly and unhealthfully scorched, as is the case
with ordinary open gas or quick combustion carbon fuel stoves, but it retains the
character of mild warmth that is imparted by hot water pipes when used for
warming purposes. The pure air warmed by the stove is not deprived of the due
proportion of moisture which is essential for a healthy atmosphere, and there are
no "cold foot bath" currents of air attendant upon the use of this stove, as caused
by the lower and colder strata of air in the apartment rushing towards the stove
to feed combustion and produce ventilation as in ordinary stoves. The air vitiated
by the respiration of the inmates or by the burning of artificial lights is carried
away by automatic action through a special arrangement for securing ventilation
in connection with stove. The heating power of the stove is susceptible of
being increased or diminished as may be found desirable, the heat becoming strong
and effective immediately after the gas is turned on and ignited, and for a given
amount of gas the effective heating power of the stove is very much greater (as,
say, from three to four times) than any gas stove heretofore in use.
"
And the nature and novelty of the Invention and mode and means of carrying
out the several improvements thereof for obtaining the said results consist all as
follows: The gas is burned by one or other of three alternative methods,-Firstly.
By the atmospheric gas. burner commonly employed in gas stoves, and which is a
modification of the well known "Bunsen burner." As employed in this stove there
are two tubes or channels of a circular, or they might be of a square or polygonal
form, ranged flat or horizontally with the jet holes or burners in the upper side or
edges, the lesser tube being within the circumference of the greater. Each tube
has a separate stop cock for the admission of gas and mixed supply of atmospheric
air, so that one or other, or both, may be lighted or brought into use. Secondly.
By an upright "Bunsen burner" provided with a cluster of tubes, or with one or
more circles analogous to that of an "argand burner," or as a tube with a hollow
broad metal top perforated with numerous minute holes. But when these burners
are on the "Bunsen" principle they are liable to a practical drawback at the timè
and while the gas is lowered, and when any current of air momentarily interferes
with the continuous delivery of the gas into the air bulb, where the gas and air
first meet to be admixed prior to being ignited. In such circumstances the pale
luminous flame is liable to "strike back and run down the tube to the jet or
nozzle where the gas is delivered. The gas then burns with a smoky luminous
Blame, producing a large volume of soot (unconsumed carbon), which is deposited
within and chokes up or injures the flues of the stove. Thirdly. To entirely obviate
these inconveniences arising out of the ordinary method of heating gas stoves there
is employed in one modification of this gas stove a burner used in chemists'
laboratories, called the "Hofmann burner," which consists of a fireclay tube, about
three inches long, one inch wide, closed at the upper and open at the lower end,
the inside bore being about half an inch in diameter. The walls of the tube are
perforated with a great number of fine holes each of a size to admit a bristle,
and burn with a small blue jet. This tube is supported in a vertical
position over a gas jet, the arrangement for supporting the tube as well as the
gas jet employed being both specially designed to answer for use in this con-
struction of stove. The jet of gas, together with an accompanying current of
atmospheric air, ascend within the tube, and in this partially admixed condition
issue through the small apertures to the exterior of the tube in jets where they
meet that further complement of atmospheric air that is necessary for perfect com-
bustion. The mixture, when ignited, developes an intense heat that rapidly causes
the fire clay tube to become incandescent. A number of these tubes, as seven or
more, according to the power desired in the stove, are arranged in a cluster or in
circles or rows, the spaces hetween being carefully regulated to about a quarter of

page_text: an inch, so as to prevent the introduction of superfluous and chilling currents of
atmospheric air. These fire clay burners are supplied with gas from a shallow box
reservoir, specially designed for the uses of this stove, and so placed that the gas
and air passing up the centre and the air on the outside becomes considerably heated
previous to combustion, and thus promotes complete combustion, and the heating
efficiency of the flame at the moment of ignition. The flame or hot products of
combustion from the burners are made to play up upon a thick plate of fire clay or
other refractory or fire resisting material, preferably suspended within an inch or
two above the top of the arrangement of "Hofinann" tubes, with the twofold object
of protecting the ironwork of the stove from the destructive action of the intensely
heated flame, and of maintaining the incandescent condition of the " Hofmann" tubes.
These important advantages are ensured by this method of burning the gas, namely:-
First. The most perfect combustion and the most intense heat of which gas is capable;
second, the power of checking the consumpt of gas, and of lessening the heat of the
stove by lowering the supply of gas without at the same time incurring the risk of
the flame "striking back" and producing a smoky flame with imperfect combustion,
which, as already stated, which, as already stated, is liable to occur under the
use of the ordinary "Bunsen" or atmospheric gas burner, unless the gas is turned
on full; third, the retention within the body, and particularly at the base of the
stroke of a reserve of heat in the fire clay material. When the gas is turned off
this reserve of heat is slowly imparted and maintains such a gradually diminishing
temperature throughout the stove as prevents the unpleasant effects of too rapid
cooling. This new or improved construction or arrangement of "Hofmann" burner
is new as adapted for use in gas stoves for heating apartments or for cooking purposes,
and for the subsidiary arrangements specially designed to utilize it in connection with
this new stove. The outlet flue which conveys away the waste products of combus
tion from the close heating chamber of the stove is of the ordinary kind, and presents
no distinctive character, except that its diameter and size is in accordance with the
size that numerous experiments have proved to be the most practically useful in
connection with this stove, and with relation to the different sizes and varying
consumpt of gas in the stoves as designed under this Invention, and which may
be fitted with a regulating valve or exit port to modify the rate of discharge when
desired, as when different powers of combustion and heating are used by the burners
with the stove. The heat is generated at the base of the stove at the lowest point
possible, preferably in a recess at the centre for the reception of the gas supply pipe
or chamber and burners, and the hot gases in their ascent therefrom are made to
traverse a series of horizontal interrupted flues, that is, abrupt reversing flues with
elbows and contracted openings within the internal hot gas chamber, and which
arrangement constitutes an important feature of this Invention. In previously
existing arrangements of gas stoves for utilizing the heat contained in the heated
products of combustion, these heated products are carried off in one of three ways.
First. They ascend instantly and without obstruction, and pass away rapidly by
the exit flues; second, they ascend and descend in vertical flues, by which arrange-
ment a certain delay (but of little effect for the object aimed at) is caused by the
progress down a descending flue; third, they ascend vertically in a chamber in a
mass of vapour made. to undulate in a wave-like continuous upward movement.
This undulating oblique movement is caused by projections from the sides of the
stove chamber or flue; but the practical effect is little, because the heated
gases still ascend rapidly in a vertical or continuous undulating manner, and
although a mass of warm vapour may fill the chamber because its outlet is
obstructed by a damper or narrow exit, yet the escaping portion of the vapour
is always the hotest, and so passes away rapidly. In the stove according
to this Invention, the arrangement for delaying the passing away of the heated
vapours is such that the stove is practically converted into one long pipe,
doubled up and folded and re-folded in horizontal lines superimposed in gradation,
like a series of superimposed rings encircling the stove. In a square stove of
18 inches, with six of these superimposed lengths of flue, the pipe is practically 35

page_text: feet long, or from 10 to 12 times the length of the stove, while in the best previous
arrangements the flue never exceeds, and rarely equals, a length equivalent to twice
the length of the stove. Moreover the movement of the escaping gases in the stove
is an ascent, not in a continuous or undulating or wave-like movement, but in
abrupt steps or sharply broken gradations, which cause a rugged broken current,
and effect a thorough mixture and agitation of the hot gaseous particles, maintaining
the equal temperature of the whole, so that the entire current progresses in a retarded
flow through the flues at mean temperature. In the continuous rapid currents of
other stoves, the hotest particles of gaseous matter invariably occupy the centre of
the current and pass rapidly away, giving off little of their heat, while the colder
products progress at a slower rate in contact with the sides of the chamber or flue,
whereby they impart a very small modicum of their heat. In such undulating
flues there exists practically two currents, the one hot, the other much colder, and
the hot current passes away rapidly. But in this new stove kneed or sudden
reversing flues constitute a novel and distinctive feature of this Invention, and give
great advantages over plain undulating or merely coil flues, by having greater length
and surface over which the hot vapour is conducted, and caused to make abrupt
turnings by impinging against the elbows or reversing vanes with sufficient force to
partially arrest and invert the internal current, and thus a new stratum of hot
vapour from the centre of the current is brought more frequently in contact with
the sides of the flues, and particularly with the lowest half of the horizontal flue,
thus making it much more effective in absorbing heat from the hot vapours. The
uniform area of these flues is also by these improvements diminished in accordance
with careful theoretical considerations, and with experimental results to that found
necessary to prevent the forcing of the gases through the flues faster than they
give off their heat to the surfaces of the flues. By the friction caused in a contracted
flue the current of vapours is retarded, while the smallness of the flue in diameter,
always within practically ascertained limits, exposes a greater part of its walls to
the hot vapours. By means of these several carefully planned mechanical arrange-
ments, the hot products of combustion, which are generated at a temperature
exceeding 1800° Fahrenheit, are made to give out their contained heat in a gradual
manner to the surfaces of the stove, and from thence to the pure air outside, or
circulating in the heated air chambers or ducts, until ultimately at their point of
escape from the outlet of the flue, the hot waste products retain only a temperature
of 200° to 250° Faht., that being as near as possible the practical limit to which
they should be cooled, and still retain sufficient heat to give them ascentional force
within the chimney. In no gas stove heretofore publicly used are these several
principles and mechanical arrangements given effect to; they constitute therefore a
marked and distinctive improvement in the construction of these gas stoves, for
which protection is sought. No atmospheric air has access to the burners and gas
flues, excepting by a small aperture, the size of which is carefully regulated, so as to
supply only the approximate quantity that science and practical experiment have
shown to be essential for the complete combustion of the gas, which is approximately
about ten volumes of air for one of gas; all above this quantity deteriorates the
heating efficiency of the stove. In all existing gas stoves the amount of air admitted
is not regulated, being practically unlimited, and rarely less than 100 times the
quantity necessary. In such ordinary stoves the heat generated goes to warm
moderately a large volume of cold air, which is immediately afterwards hurried up
the chimney, having contributed usefully rarely more than 25% of the heat
generated. In the gas stove, according to this Invention, the arrangements of the
sizes of ducts, or slides, or valves for admitting and restricting the quantity of
atmospheric air necessary for supplying combustion as herein specified, form a
further improvement of this Invention. The stove presents a very large external
surface, over which the heat generated within the stove is diffused by conduction or
radiation. This extended outer heating surface is obtained by duplications of the
external casings, forming one or more annular or other vertical air current channels
below a close inlet air chamber forming the base of the stove, and an exit top

page_text: 1orming the capital and top of the stove, and through which the pure air is made to
pass in large quantity and becomes warmed to a mild heat, and a further greatly
extended heating surface is obtained by introducing within the body of the stove a
greater or lesser number of pipes or caliducts arranged vertically or obliquely right
through the heating gas flues, so that the air to be warmed may escape rapidly from
the heating surface, and not get overheated or scorched. The mechanical arrange-
ments through which the external walls of the stove are duplicated, and by which
the conduits for warming pure air within the body of the stove are placed in
position, are peculiar to this Invention, and form a special novelty thereof.
The air thus warmed by connection and conduction or radiation within the dupli-
cate casings and air warming tubes and conduits ascends to the top of the stove, and
is there deflected by a covering lid with lateral openings, through which it is
delivered into the apartment. A continuous gutter made to contain water runs
round the circumference of the stove at the top, and is protected and partly con-
cealed by the covering lid. The warm air (delivered through the lateral opening)
is made to pass over this water reservoir, from which it absorbs moisture in a
quantity sufficient to replace that which it lost in passing through the warm air
conduits and duplicate linings. The gutter reservoir presents gradations of depth
and surface, being widest at top. and narrowest at bottom, stepwise, so that,
according to the height to which the water is filled into this, it gives more or less
heating surface for the hot air to pass over, and so takes up moisture propor-
tionately; consequently a dry or humid atmosphere may be procured to any
degree that may be desired to meet medical requirements or individual peculiarities
of sensation. This improved means of supplying water or moisture to the heated
air forms another improvement of this Invention, and may be adjusted in accordance
with rules framed from the indications of a wet and dry bulb thermometer. The
gutter reservoir is so placed in an overhanging position around the top of the stove
that the water does not get overheated so as to boil or give off visible steam, as
occurs in the arrangements connected with other stoves where this object of sup-
plying lost moisture is sought to be obtained. By another improvement of this
Invention the air supplied for gas combustion, together with the air to be warmed
within the stove, does not enter at the base, as in all existing arrangements, but is
taken in through openings in the upper part of the stove, or by other air passages
specially designed in connection with the stove, and carried down to an air inlet-
chamber at the bottom of the stove. From this chamber by a special arrangement
a regulated supply of atmospheric air is given off for gas combustion to any of the
arrangements of burners herein described. From the same chamber the air in large
volume ascends through the annular or duplicate casings and tubes, or both, when
fitted with these, as already described, to the upper part of the stove, to be there
distributed in lateral currents to the apartments. This method of supplying the air
both for combustion and heating the apartment from above prevents "cold foot
bath" currents coming along the floor towards this heating stove, and obviates at
the same time the need of resorting to costly, inconvenient, and often less practical
structural arrangements, whereby air is supplied through the walls of an apartment
from the outer air. The stove exit pipe for conveying the waste gases to the
chimney is surrounded with another tube, forming, an annular duct round the former
opening into the chimney, partially closed at the inner end by a valve or otherwise.
The external tube is formed with an angular or square slot or opening, which
always remains open in the absence of other ventilating arrangements, and pre-
ferably fitted with a sliding or swivelling sleeve to regulate the amount of opening,
thereby securing two objects, namely, a continuous drawing off from the apartment
of a quantity of vitiated air, and also with a light hanging safety valve or other
equivalent which would open with the slightest back draught, making safe provi-
sion against a "blow down" in the chimney, which would interfere with the proper
ction of the stove. The slide or cover on the opening would regulate the amount
of ventilation desired in the apartment, and the construction of this addition forms.
nother important improvement connected with this gas stove. A typical construc-

page_text: tion or combination of the parts of this Invention or improvements as adapted and
preferred for a gas stove for general heating purposes, as for heating the rooms or
apartments of houses, offices, or halls, and other places, consists in fitting preferably
two concentric rings of gas pipes or ducts, or a chamber with small jet holes or
burners to burn either in the Bunsen or the Hofmann system, with a great part of
the air required for combustion passed in and admixed with the hydrocarbon or
ordinary inflammable coal gas used for illuminating purposes within the Bunsen jet
tubes or the Hofmann vertical fire-clay burner, and thus made to burn with the
blue flame, which gives off more heat than light, but preferably made so that the
blue jets play upwards at an angle towards each other in the Bunsen arrangement
over an annular opening for admitting air to assist complete combustion outside the
jet rings, which are set in the lower centre closed in part of the combustion
chamber of the stove, having a fire-clay block, perforated dome, or other equivalent
above, and placed within a recess in the middle of the basement closed-in, air-
receiving, circulating, and heat-absorbing part or chamber of the stove, formed with
an outer vertical, cylindrical, or other shaped case or cases surmounted with a corre-
sponding closing chambered top or capital, which, as well as the base, might have
an ornamental appearance or character, all surmounted with an ornamental, curved,
or plate cover above this chambered capital, with a narrow open recess between
them for the escape of the circulating heated air laterally into the apartment over
an open, annular, or other water vessel or gutter formed in the top chamber round
its outer edge or capital, up into which the current of heated fresh air is led from
the lower chamber through the outer casing, and by a ring or other set of vertical
tubes jointed or opening up from the bottom inlet close air chamber, into which
the air is led down preferably from above by two, three, or more outside
pilaster-like pipes or tubes (or other equivalent) opening into the lower close
basement air chamber, these tubes being either led up through the top
cover to receive the circulating air from above this, or made shorter and
closed at the upper end, and formed to receive the air through a slit or opening at
the back part of the top of each column, tube, or through openings in their ornamental
capital, and preferably regulated by slides or sleeves. A central case, closed at the
lower end, is also fitted over the gas burner, opening into the top escape hot air
circulating chamber, with a smaller central downward conducting current air tube
or pipe opening and led down from above the plate top or cover, and opening into
and near the closed-in bottom of the larger central heating chamber. The annular
close flue space or chamber between these central air circulating pipes and the outer
annular case or shell of the stove (above the gas burners and flame or fire chamber)
all round the heat receiving air tubes is fitted with two, three, or more horizontal
discs or division galleries, dividing this into elbowed kneed spaces or flues fitted
with up-take openings at each alternate opposite side, and with vertical baffle plates
or vanes at the outer or inner edges between the tubes and sides, or projecting down
or up from the horizontal divisions, so as to reverse, retard, or invert the upward
current of the hot waste gaseous products of combustion on their course from the
burners to the top escaping division fitted with the outlet flue leading to the
chimney below the top air chamber or capital. Thus these gases are caused to
traverse alternately from side to side in each division flue as they ascend, and by
curling and agitating them they are also caused to circulate round and impinge on
the sides of the air tubes and case, so as to impart their heat thereto, which is
taken up by the air circulating up through these, and which escapes at the top of
the stove by preference laterally, to mix with and heat the air of the apartment,
receiving a regulated supply of moisture as it escapes over the water gutter round.
the top chamber under the lid or top. For the perfect combustion of the gas or
hydrogen and carbon therein, and the production of the greatest amount of heat
possible therefrom, the proper proportion or amount of air to be mixed or led thereto
is regulated by a valve slide or sleeve on the several inlet ducts or openings, and a
damper may also be fitted in the escape flue or pipe or the waste gases leading to
the chimney. Such regulating valves may also be fitted on the inlet or outlet air

page_text: ducts of the heat receiving and circulating air chambers to regulate the currents
through them to maintain the best uniform or mean heat of the stove for taking up
and utilizing the greatest amount of heat possible from the heated gaseous products
of combustion during their ascension up the inner reversing current divided flue
chamber, and to suit the number of gas jets burning at the time, that is, either of
the minimum, medium, or maximum heating power respectively of the stove in use
for the time being, as when the smaller inner or the larger outer ring of jets are
lighted, or when both rings of jets are lighted; and, further, these gas holes or burners
should be small, and preferably so close that the gases and air in passing to or
through the small holes thereof would be heated to near the combustion tempera-
ture to burn with a hot blue flame, and not with any of the yellow or white flame
which produces smoke, and is wasteful when applied for heating stoves. It will be
understood however that one or any other number of rings or straight or polygonal
rows of the Bunsen jet tubes (or the Hofmann vertical multiple jet burner) may be
used, although two rows only have been described in this first modification, and
that when a cheerful appearance of light is desired in these gas-heating stoves the
jets may be made to play on and heat asbestos or other such material to a white
heat, and be reflected or made to shine through transparent windows in the outer
case of the stove, formed of glass, mica, or other material.
Where very high temperatures are desired or required in such heating stoves in
smaller space than by the Bunsen burners, as for the heating or drying of articles, or
for cooking purposes, it is preferred to use the Hofmann fire-clay burners, or small
vertical cylindrical cap of a considerable thickness (as from 1 th to th of an inch)
pierced all round the circumference with very fine holes, and close ends above, with the
lower open end of each set on three pronged galleries or equivalent supports over a
small vertical short gas tube projecting up from the gas vessel, and with a small hole or
metal burner in it entering some little distance into the Hofmann burner, and all pre-
ferably ranged in a circle or cluster, each burner being about a fourth of an inch or so
apart from the other to allow the small blue jets to burn freely all round each tube
burner. The spaces between their short supporting tubes admit the air to the under
open end of the inner burners of the set or cluster, the heat of which would heat the air
and the gas supply rings or chambers carrying the whole of the burners, as well as
heat the large fire-clay gas-burners to a red heat, so as to heat the gas and air
passing through the fine holes in their thick sides to nearly the combustion tempe-
rature, and also heat any little air passing up to the jets round their outer circum-
ference, which has the effect of producing a very high local red heat when surmounted
by a disc or ring of asbestos or block of fire-clay, with free escape for the upward
currents of heat round or through openings in these, so as to answer for the
said warming or cooking purposes, and protect the metal cases, suitable also
for close and open fire ranges used for cooking. These new or improved con-
structions of gas heating stoves would generally have their shells or cases and
air current and circulating tubes formed of thin sheet iron, steel, or other metal,
with smooth or corrugated hard rolled or clean surfaces (or they may be tinned or
galvanized) to prevent corrosion as much as possible, coatings of tar, black varnish,
or other substance which would give off noxious gases being preferably dispensed,
with; but for some purposes, when desired, these cases or ducts might be made of
fire-clay, or of double cases of thin sheet metal fitted with corrugated or other fire-
clay blocks along their sides, or filled or partially filled with broken, granulated, or
crushed fire-clay bricks or blocks, or other equivalent inoxious and fire resisting
material, as for the sides of the fire chambers of these cooking gas stoves, which
would either be set in recesses like fireplaces, or have wide conducting inverted
funnel shaped conduits or other equivalents to conduct the waste deleterious gases of
combustion upwards through the roof or to the chimney, so as not to mix with the
air of the apartment where these hot open cooking stoves are in use; or these
waste gas conducting covers might be made movable to lift up and down when
these gas heating or cooking stoves are used open within the apartments. And as

page_text: a general rule the drawing off pipes or flues for the waste combustion gases ought
to be made as small as will properly conduct them off at the lowest temperature
and expansion that will carry them up and out of the rising discharge column, and
these gases being much heavier than air, this temperature, it seems from experi-
mental tests, should not be reduced below 200° or 250° Fahrenheit, and not at a
greater speed than would carry off all the products of the gas and air burned as
admitted to the combustion chamber, and about 7 to 10 times the quantity or cubic
feet of air to that of gas requires to be admitted to the burners or to the jets in the
combustion chamber to give complete combustion with the blue or pale luminous
flame, which gives the maximum of heat from the gas. The length and peculiar
kneed and retarding construction' of the gas heating flues for reversing the currents
are made such as to prevent the escape of the waste gases at a higher temperature
than from 200° to 250° Fahrenheit, so as to utilize all the heat produced by the
combustion of the gases in these new or improved gas stoves; and it will be under-
stood that although a circular and annular arrangement of the case of the stove and
its air circulating tubes have been described, they may be of a rectangular, polygonal,
oval, or other shape, and either with or without the outer circulating narrow air
case or the tubes, as may be desired, and the fire-clay blocks or cases might be
made to protect the air circulating tubes and deflect the gases as desired; and the
air to be heated, instead of being conveyed down by outer column tubes or pilasters,
might be led down by openings at the top of the outer casing, and through it to
the lower air chamber, or by other special tubes or ducts for the purpose from the
upper part of the apartment, or it might be from the outside of the house.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Adams in the Great Seal Patent Office on the 19th
September 1879.
:
JAMES ADAMS, of Glasgow, in the County of Lanark, North Britain, Doctor of
Medicine. IMPROVEMENTS IN GAS STOVES."
"
My said Invention relates to improvements in the constructions and arrangement
or combination of the parts of gas stoves.
I employ in gas stoves a burner consisting of a group of hollow perforated tubes
or other forms of fire clay or other refractory material supplied internally with a
mixture of gas and air, which passing through the perforations burns on the outer
surface. These refractory tubes or forms are enclosed in a case or chamber
which prevents free access of air to their exteriors where combustion takes place,
but by perforations a small quantity of air is admitted and allowed to pass around
and between the refractory burner tubes or forms to ensure complete combustion,
thus only the smallest practicable excess of unconsumed air is permitted to mix
with the products of combustion.
The products of combustion are led to a chimney by a ziz-zag ascending channel
or flue in which they are detained until they have parted with all their available
heat, and other channels or ducts lead currents of pure air along the heated walls
of the flue channel, and the air so warmed is allowed to re-enter the room or apart-
ment in which the stove is used.
The walls of the air channels or ducts present an extensive surface to take up
the heat from the products of combustion traversing the flue channel, and conse-
quently these surfaces do not become over heated.
The air entering the stove is caused to pass in at or near the top and thus a supply
free from dust is ensured and drafts along the floor of the apartment are avoided.
The warm air issuing from the stove is caused to pass over water contained in a
trough so formed that by filling it more or less the surface of water exposed to the
warin air may be varied in extent.
The burner as I prefer to construct it consists of a group of fire clay tubes of
from two to three inches in length or height, and from three quarters to an inch in
diameter, closed at the upper end and open at the lower, the inside bore being about
half an inch in diameter. The walls of this fire clay tubular burner are perforated
with a great number of fine holes, each of a size to admit of a bristle. Such
refractory burner tubes are at the present time occasionally employed in chemists'
laboratories. I arrange these burner tubes in a vertical position over gas jets. The
jet of gas enters the lower open end of the fire clay tube by a small central nozzle,
together with an accompanying current of atmospheric air entering by the annular
space round the gas jet. The air and gas ascends in a mixed state up the centre of
the fire-clay tube, issuing in minute jets through the small apertures in its walls to
the outer surface, where it meets that further complement of atmospheric air neces-
sary for perfect combustion. The mixture when ignited burns with a pale blue
flame and develops an intense heat that rapidly causes the fire clay tube to become
incandescent. A number of these tubes, less or more, according to the power or
heat desired in the stove, are arranged in a cluster, or in circles or rows at the lower
part of a chamber which shelters them from the free access of air, and the space
between them is such as to prevent the introduction or circulation of superfluous
and chilling currents. These fireclay burners are supplied with gas from a shallow
box, and the pressure at which the gas is admitted to this box is uniformly main-
tained by the employment of an efficient gas pressure regulator. The gas box is so
placed that the gas and air required for combustion become considerably heated
previous to ignition and thus promotes the complete interpenetration of gas and
The flame or hot products of combustion from the burners is made to
air.

page_text: play upon fireclay or other fire resisting material with the twofold object of
protecting the iron-work of the stove from the destructive action of the flame
and at the same time accumulating and maintaining in a solid reservoir an
intense heat in the central lower part of the stove and a high heat at burner.
Three important advantages are ensured by the use of this burner, namely,
first, perfect combustion and the development of intense heat; second, the power
of checking the consumption of gas and of lessening the heat of the stove by
lowering the supply of gas without at the same time incurring the risk of the
flame striking back and producing a smokey flame with imperfect combustion,
which is liable to occur under the use of the ordinary Bunsen tubular atmo-
spheric gas burner unless the gas is turned on full; third, the retention within
the body, and particularly within the base of the stove, of a reserve of heat in
the said fireclay or other material. The hot gases in their ascent from the burner
are made to traverse a series of superimposed chambers, which by communicating
opening become a zig-zag flue within the stove.
This arrangement delays the passing away of the hot gases. In a vertical cylin-
drical stove of 18 inches in diameter with six of these superimposed lengths of
chamber this flue is practically 35 feet long, or from 10 to 12 times the length of
the stove. Consequently there is sufficient capacity in the flue to ensure the pro-
ducts of combustion being retained until they have parted with all their available
heat.
:
Moreover, the movement of the escaping gases in the flue being by abrupt steps
a thorough mixture and agitation of the hot gaseous particles is effected, thereby
maintaining the equal temperature of the whole. In the continuous rapid currents
of other stoves, the hottest particles of gaseous matter occupy the centre of the
current, and pass rapidly away, giving off little of their heat, while the colder
products progress at a slower rate in contact with the sides of the flue, to which
they thus impart but a very small modicum of their heat.
An extended surface for imparting heat to the currents of air passed through the
stove is obtained by duplication of the casing to form a pure air conduct; and a
further extended heating surface is obtained by introducing air pipes passing down
through the body of the stove and through the zig-zag flue. By all these air ducts
air ascends from a closed air chamber in the basement of the stove, to which
chamber the air is supplied by other descending cold air ducts or channels. The
air warmed within the double casing, and air warming tubes and conduits, ascends
to the top of the stove, and is there deflected through lateral openings by which it
is delivered in a heated state into the apartment. A continuous gutter made to
contain water is formed or fitted round the circumference of the stove at the top,
and is protected and partly concealed by the covering lid. The warm air delivered
through the lateral opening is made to pass over this water reservoir from which it
absorbs the water in a quantity sufficient to restore its moisture which is lost in
passing through the warming ducts or channels. The gutter reservoir is widest at
the top, and becomes narrow towards the bottom, stepwise, so that according to the
height to which it is filled, there is a more or less moistening surface for the hot
air to pass over. Consequently, a dry or humid atmosphere may be procured to
any degree that may be desired to meet medical requirements or individual
peculiarities of sensation. My improvement burner is applicable also to cooking
and other gas stoves, and the arrangement of flues and air ducts which I have
described, and other parts of my Invention are applicable to gas stoves in which
my improved burner is not employed.
In order that my said Invention may be fully understood and readily carried
into effect, I shall now describe the Drawings hereunto annexed.
.
Figures 1 and 2 are a vertical section and a horizontal section respectively taken
near the lines 1 - 1 and 2-2, each on the other. They represent the general
arrangement or combination of the parts of a gas heating stove, constructed in
accordance with my Invention, and this arrangement is typical and illustrative of
the Invention as applied to stoves for heating the rooms or apartments,

page_text: --
Figures 3 and 4 are a vertical and a horizontal section taken respectively on the
lines 3- 3 and 4- 4, each on the other, of a more simple and inexpensive
arrangement and combination of the parts of a gas stove constructed in accordance
with my Invention. Figures 5, 6, and 7, are a vertical section and two horizontal
sections respectively, the first taken near the irregular line 5 - 5 in Figure 6, and
the two latter near the lines 6 - 6 and 77, 7' 7' in Figure 5, of a gas
cooking stove constructed in accordance with my Invention.
--
Figures 8 and 9 are vertical aud horizontal sections respectively taken on the
lines 88 and 9 - 9, each on the other, of a gas stove for heating tailors' or
laundry irons, constructed in accordance with my Invention. Figure 10 shews to a
larger scale a vertical section of the parts constituting the burner, and having
immediately to do with the maintenance of proper combustion. The burner in this
case is provided with a hollow perforated fire clay dome B over the fire clay tubes
b, as an accumulator and protector, to concentrate the heat in the burner, and
provide for its dispersion, without injury to the surrounding metal work. Referring
particularly to Figures 1 and 2, A is a shallow gas supply box fitting to the central
part of the hollow close caseinent air chamber D, immediately beneath the burner
chamber B. Gas at uniform pressure is led into the box A by gas pipe g controlled
by the stop cock g'. The cover or top of the gas chamber A is fitted with the
cluster of short gas jet tubes a, screwed into the top of the gas box A, and over this
box there is an air supply chamber a' with narrow openings all, for admitting to it
a suitable quantity of air from the basement chamber D. The chamber B contains
the sét of fire-clay tubes b, which are each mounted over a gas tubo a in sockets.
These sockets are formed in a closing in plate 6', which closes at the top the air
space a' above the gas box A, except that there is a ring of small holes b¹¹ in
the plate b round each tube b, to adinit sufficient air to supply the jets burning
outside the tubes b, besides that which ascends the tubes b along with the gas. The
tubes are ranged vertically within the burner chamber B, which opens into the
internal heating chamber B¹, C, of the stove through which the hot gaseous
products of combustion pass upwards. The proper quantity of air for each tube b
passes by a small annular hole a², round each gas tube a in the closing in plate a³,
mounted just above the inlet air openings a', and some distance below the tubes b.
When desired, a ring sleeve, as at I*, on the outside of the case B in Figures 1 and
10, may be used for controlling the inlet of the air through the apertures a¹¹, and
this may be shifted or set by a suitable handle for the purpose from the outside of
the basement chamber D of the stove. The stove rests on low feet f, to keep it a
little off the floor. In place of the tubes b, other hollow perforated forms of
refractory material may be employed, as is illustrated by the Figures 13, 14, and
15. Other refractory substances may be employed in place of burnt fire clay, but
this material is very suitable.
The body of the stove is cylindrical outside with double cases D¹¹, D², jointed
air-tight in sockets in the top of the basement chamber D, and surmounted with a
corresponding tight closing top D' and chambered capital E, E'. There are openings
round the edge of the top chamber which direct the heated air laterally into the
apartment over the surface of the water contained in the water vessel or gutter Eu
formed in the top D¹ round its outer edge or capital. A great part of the air to be
heated is led down to the air chamber D from the upper part of the stove by outside
hollow pilaster like pipes or tubes G opening into the bottom air chamber D. These
tubes G are closed at the extreme upper ends in the top D¹ of the stove, but have
each at the back and just below the upper end a concealed slot or opening G₁ to
admit the air. These air inlet openings G in the tubes G are each preferably fitted
with a regulating slide or sleeve G" to control the admission of air. The air to be
heated is led up from the lower chamber D through the double casing D1, D2, d,
and through a ring or set of vertical tubes F opening up from the bottom air
chainber D into the top chamber D¹, E. A large tube or case H closed at the lower
end by the fire-clay block B is fitted vertically in the centre of the stove and
heating chamber B, C, over the cluster of refractory tubes b, with a smaller hanging

page_text: tube H mounted in the centre which conducts a current of fresh air from above
the stove down into the bottom of the chamber H, where the current is reversed
and passes upwards through the annular duct or chamber h between the outside of
the central tube H' and the exterior tube H. This air escapes in a heated condition
nt the top, as indicated by the arrows over the ring water trough E. The flue
chamber or space B, C, which receives the heated products of combustion is divided
by horizontal division plate C¹ forming horizontal flue chambers with uptake
openings c alternately on opposite sides. The hot products of combustion from the
burner are deflected from the fireclay block B and traverse alternately from side
to side through the openings c, c, in each horizontal flue chamber as they ascend,
and they are made to impinge effectively on the sides or walls of the flue and of
the air heating and circulating channels or ducts by which pure air ascends from
the basement air chamber D so as to impart their heat thereto. The heat is
absorbed and taken up by the pure air which escaping at E mixes with and
warins the air of the apartment.
The arrows on the Drawing represent the air currents, and the darts the hot
products of combustion.
The stove exit pipe J for conveying the waste products to the chimney is
surrounded with another tube J₁ forming an annular duct j round the outside of
the former opening into the chimney. This duct is partially closed at j₁ but is fitted
also with a swinging automatically acting valve j". The external tube J' is formed
with a slot on the upper side which should always remain open in the absence of
other ventilating arrangements in the apartment. The light hanging valve j¹¹ fitted
at the end of the annular channel j opens with the slightest back draught so as to
make a provision against any blow down in the chimney which might interfere with
the proper action of the stove.
When a cheerful appearance of light is desired on the outside of the stove an
entrance passage or channel K may be provided as indicated in Figure 2, which
answers also for lighting from the outside, or when desired a small pilot light may
be kept burning to ignite the gas jets.
Referring to the modification of the improved heating stove, shewn in Figures 3
and 4, it will be seen that it is substantially the same as that described in reference to
and shewn in the former Figures 1 and 2, except that it is very much simplified by
dispensing with the inlet air ornamental column tubes G and substituting one inlet
rectangular duct or channel G* at the back of the stove where it draws the supply
of air from the apartment near the upper part of the stove to prevent floor or foot
draughts and leads it down into air chamber D at the base of the stove. The set
of air heating tubes F are also dispensed with, so that the central air heating tubes
Hand H are enabled to be made much larger with greater heating surface than in
the stove represented by Figures 1 and 2. This stove also is shewn without a fire-
clay block or dome B or B2.
Figures 5 to 7 inclusive represent a cooking stove, constructed according to my
Invention. It has a basement air receiving chamber d', D, preferably made of cast
iron, and carried on feet ƒ a short distance off the floor. The air led into it by the
vertical duct G* led down from the upper part of the stove or apartment. This
basement chamber D, d, has erected or formed over it, (first), the large main body
cylindrical chamber C, forming the roasting and baking oven, communicating at
top; (secondly), the chamber C above, into which the hot gaseous products of
combustion from the oven C are discharged, and within and over which the various
operations of stewing, broiling, toasting, or other like cooking operations are or
may be carried on; and (third), the hot plate top C³ over the chamber C. The
top plate is pierced with openings C, fitted with closing flat covering plates C³, as
in any ordinary cooking stoves. The wells and main body parts C, C, of the stove
are made with a double case C, C, as also the large door Cinto the oven C
in front, preferably of good strong tin plate having a bright or polished surface.
The space or jacket C* between these outer cases C, C1, is closed in, quite air
tight and made wide enough, as from an inch to two inches, to enclose or confine a
.

page_text: layer or sheet of air all round the stove. This space may also be filled with other
slow conductors of heat when desired. The sole plate C¹ of the upper cooking
chamber C. forming the roof of the oven, as also the top hot plate C³, are for
stability preferred to be made of cast iron. This stove is shewn as cylindrical or
drum shaped, which I prefer for small sizes, but they might be made square or
polygonal when desired. The upper sole plate D is pierced with holes a; fifteen is
the number shewn; the gas vessel or pipe A is attached to the under side of the
said sole plate D, and is also pierced with holes into which the stems 6111 are screwed
of the supporting galleries b¹ of the fire clay tubes b, as shewn particularly and to a
large scale in Figures 11 and 12.
The holes a in the sole plate D are so large as to leave a free margin of open
space round the stem 61 of the holder b', of a size as shown, that will pass only a
suitable quantity of air, and the spaces by which air is permitted to ascend to com-
plete the combustion at the exterior of the refractory tubes b are of small size
so that no more may enter than is necessary to ensure perfect combustion.
On the under side of the sole plate D is formed or fitted an air chamber which is
supplied by a rising pipe G*. A screen B¹ of thin sheet iron is fitted and secured
upon the sole plate D and it extends upwards to within a few inches of the top of
the oven C, and laterally to a distance sufficient to enclose the lower burner. The
screen B¹ as it ascends inclines towards the side and back wall C of the oven C
so that there is a space of half an inch or thereby between the top of the screen B¹
and the wall C of the oven C, thus a deep longitudinal combustion chamber B*,
about one and a half inches wide at bottom and half an inch wide at top is formed,
within which the hollow refractory burner tubes b are enclosed.
A hole in the screen B¹, covered by a revolving flap B² gives admission to the
burners b for lighting. The sole plate D is perforated with a small drain hole or
duct o into which the outlet or drain o¹ of a small dripping pan ol is fitted for con-
veying juices of meat or fluid from the oven C into a flat dish O, resting on the
ground and partially filled with water into which the beak o of the drain pipes
dips, thus air is excluded from entering the stove through that channel. The hot
products of combustion enter in top chamber C2, in front by the duct C, and in
passing back are interrupted by baffle plates c', c' projecting down from the top
and a screen c¹, by means of which the hot vapours are made to traverse from side
to side and from top to bottom of the chamber C2, so as to delay their final discharge
through the stove pipe J at the back leading to the chimney. Into the openings C
there may be lowered saucepans, kettles, vegetable, pudding, or other dishes, and.
the hot vapours then circulate round the sides of these vessels. There is also fitted
in the top of the stove another burner of my improved construction, within a burner
chamber or jacket B. This top gas burner B is designed for grilling, toasting, or
boiling operations, and air for combustion is led direct from the outside of the stove
to it through a shallow trunk a¹¹.
Figures 5 and 6ª shew a vertical elevation and a plan, half in section, respec-
tively, on the lines 1- -1 and 2- -2, each on the other, of a simple construction of
cooking stove. This cooking stove consists of a cast iron bottom plate D and upper
plate D, bolted together with a short fire-clay cylinder B and outer sheet metal
case D between them, d is the air supply space outside and B the burner chamber
inside. The burner and part immediately concerned with the combustion are sub-
stantially as already described, and are clearly shewn by the Drawing. The air
enters the jacket d by the opening d", at the upper edge of the case D", and the
narrow slit or ring of small holes a" admits the air to the air feeding chamber a'
surrounding the gas tubes a and gas supply vessel A.
The top plate D' has formed on its upper surface a short ring of projections for
setting pots or pans or other cooking utensils on or over the burner chamber, and
for steadying the shallow portable removable gallery L.
This movable gallery has open sides, and carries a thin fire-clay plate or tile L.
A hot chamber L² is formed over and around the plate L by the use of the outer
removable cylindrical case L³ fitted with a finely perforated disc Llll on the top

page_text: The upper surface is provided with short barbs or pins, and is used as a hot plate
for keeping a kettle or other vessel warm. It has a contracted rim to converge the
hot escaping currents against the vessels.
A door L is fitted in front of the body of this case or cooking chamber L². The
top enclosure or entire stove may be made of cast metal.
Figures 8 and 9 represent a gas stove for heating tailors' or laundry irons. This
stove is constructed of a square or rectangular form, with a basement plate and air
supply chamber D, supported on feet fa little off the floor, and fitted with cluster
or double rows of refractory burner tubes b, and the other gas and air adjustments
ranged in the form of the letter H within an enclosing chamber B, with gas and
air supply box and details, all substantially as already described.
The burner chamber B is covered by a perforated cap B2 in the lower central
part of the main heating chamber C, in which the irons U are placed to be heated.
The sides of this chamber are made double or cased, preferably by inner cast iron
plates cand an outer sheet iron case c¹¹. This stove is divided into two separate
compartments by the two strong perforated plates or supporting galleries T and T.
Three irons are mounted on each gallery over openings formed under them nearly
the shape of the iron, and on ridges on the upper surface of the supports T, T..
The double cased doors C in front are hinged at their top edge to cross bars
at C, so as to close as nearly air tight as possible at their lower edges by their
own weight on angled cross bars at C*.
Above the top plate C¹ of the heating chamber C a closed in chamber C² is formed
with a strong cast iron plate C³ above for use in a hot plate when required.
In this arrangement the air enters, as in Figures 3 and 5, by a special pipe G*
from the upper part of the stove, and is led into the air chambers D and A under
the burner to support combustion. The hot products of combustion ascend through
the chamber C acting on the under side of the irons U, partly by direct radiation
and partly by contact of the hot products of combustion. The waste gases pass
off by the escape port c in the front of the upper plate c¹ through the upper
chamber C2 fitted with the baffle plates projecting up from the plate C¹ and down
from the plate C³, so as to retard the escaping gaseous products, and cause them to
impinge and act more effectually on the under surface of the plate C³.
Having thus particularly described the nature of my said Invention, and the
nanner by which it is to be performed, I would have it understood that I
claim,―
First. The combination in a gas stove, substantially as described, of a burner fed
with a mixture of gas and air, and consisting of hollow perforated forms or tubes
of fire-clay or like refractory slowly conducting material, with flues for leading
away the heated products of combustion, and with ducts or passages heated by the
said flues, such ducts or passages being employed to warm air, which when thus
warmed is permitted to escape into the room or place in which the stove is
employed.
Second. The construction of the burner, substantially as described, such burner
consisting of hollow perforated forms or tubes of fire-clay or other refractory slowly
conducting material, supplied internally with a mixture of gas and air, and enclosed
in a casing or chamber preventing the free and uncontrolled passage of air around
and amongst such burner tubes or forms, but by suitable perforations or apertures
permitting a small and suitable quantity of air to enter to complete the com-
bustion.
Third. The arrangement and use in gas stoves, substantially as described, of air
inlet ducts having their mouths or open ends by which air is taken into the stove
at or near the top of the stove.
Fourth. The combination and use in gas stoves of double outer casings (D¹¹, D²)
and of internal vertical tubes (F, H, H¹) for the circulation and heating of the pure
air, substantially as described.
Fifth. The arrangement and use in gas heating stoves of a series of superimposed.
chambers forming horizontal flues (C, C), communicating with each other by

page_text: openings, so arranged that the whole forms an ascending zig-zag flue for conveying
away the heated products of combustion, substantially as described.
Sixth. The arrangement and use in gas heating stoves of a gutter (E) for con-
taining water, made with gradations of depth and surface, and so placed that the
heated air may pass over the water surface, substantially as described.
Seventh. The general construction or combination of the parts of gas stoves, sub-
stantially as described and illustrated by the accompanying Drawings.
In witness whereof, I, the said James Adams, have hereunto set my hand
and seal, this Sixteenth day of September, in the year of our Lord One
thousand eight hundred and seventy nine.
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
JAMES ADAMS, M.D. (L.S.)