IMPROVEMENTS IN THE CONSTRUCTION OF OVENS HEATED A
Year: 1882

page_text: LETTERS PATENT to William Arden Crommelin, John Lees, Henry Spain and
William Henry Thompson all of 76 Coleman Street in the City of London
for an Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF OVENS HEATED
A
PROVISIONAL SPECIFICATION left by the said William Arden Crommelin,
John Lees, Henry Spain and William Henry Thompson at the Office of the
Commissioners of Patents on the 21st December 1882.
WILLIAM ARDEN CROMMELIN, JOHN LEES, HENRY SPAIN and WILLIAM HENRY
THOMPSON, all of 76 Coleman Street, in the City of London,
"IMPROVEMENTS IN
THE CONSTRUCTION OF OVENS HEATED BY GAS,"
The objects of our said invention are to construct Bakers' and other ovens, in
such a manner that there shall be no smoke arising from the combustion of the
fuel, such fuel being either ordinary coal gas, or any other suitable and available
gas for the purpose. Also to promote economy in the consumption of gas by the
means and arrangements for utilising the caloric arising from or produced by the
combustion thereof, and also to enable the operatives to have the desired
temperature under perfect control at all times.
In constructing ovens in accordance with our said invention, we make use of
Bunsen or other Gas burners, and place the same either vertically, horizontally, or
diagonally, in such a manner that the flames enter suitably formed Blues, surround-
ing or partially surrounding the internal walls forming the shell or lining of the
oven. "A sufficient number of gas burners entering separated fues, are provided,
in order to cause a sufficiently bigh temperature to be distributed in and around
the oven, for effectually carrying out the desired operations. When bunsen burners
are used, suitable regulating valves are fitted to allow. a proper supply of atmo-
spheric air to enter and mix with the gas. Suitable arrangements are also made to
cause the air and gas to take up and utilise the waste heat which would otherwise
pass away to the chimney, by which means the air and gas arrive at and pass
through the burners superheated, thus greatly conducing to economy.
The flues through which the heated gases pass are carried in horizontal channels

page_text: under the bottom: in vertical or parallel tiers of horizontal channels in the sides:
in horizontal channels under or over the roof lining: and finally sometimes in
descending channels to the foot of the chimney; and such channels may be
formed of fire-brick, fir-clay, cast or wrought metal, or pipes of various sectional
forms.
Between the inner walls or shell of the oven and the outer walls thereof we
interpose a layer or layers of wool slag, abestos, or other suitable non-conducting
material, in order to prevent loss of heat by conduction or radiation, and to render
the same economical in fuel, and effectual in working.
In cases where our said improved ovens are constructed for baking bread, the
space between the floor of the oven and the ordinary ground line may be fitted up
as a proving oven or ovens.
The usual flue over the door is constructed with a moveable door or valve
thereto, and dampers are fitted to the chimney and flues, where necessary.
Our said improvements are applicable and adaptable to the construction of
ovens for cooking, baking bread, pastry, pottery, porcelain, Art tiles, and otherwise
where definite and controllable degrees of heat are desirable or necessary.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Arden Crommelin, John Lees, Henry Spain and William
Henry Thompson in the Great Seal Patent Office on the 21st June 1883.
WILLIAM ARDEN CROMMELIN, JOHN LEES, HENRY SPAIN, and WILLIAM HENRY
THOMPSON, all of 76. Coleman Street, in the City of London IMPROVEMENTS IN
THE CONSTRUCTION OF OVENS HEATED BY GAS
The objects of our said invention are to construct Bakers' and other Ovens in
such a manner that there shall be no smoke arising from the combustion of the
fuel such fuel being either ordinary coal gas or any other suitable and available
gas for the purpose Also to promote economy in the consumption of gas by the
means and arrangements for utilising the caloric arising from or produced by the
combustion thereof and also to enable the Operatives to have the desired temperature
under perfect control at all times.
In constructing Ovens in accordance with our said Invention we make use of
Bunsen or other Gas burners and place the same either vertically horizontally or
diagonally in such a manner that the flames enter suitably formed flues surrounding
or partially surrounding the internal walls forming the shell or lining of the Oven.
A sufficient number of gas burners entering separated flues are provided in order
to cause a sufficiently high temperature to be distributed in and around the oven
for effectually carrying out the desired operations. When Bunsen burners are
used suitable regulating valves are fitted to allow a proper supply of atmospheric
air to enter and mix with the gas. Suitable arrangements are also made to cause
the air and gas to take up and utilise the waste heat which would otherwise pass
away to the chimney by which means the air and gas arrive at and pass through
the burners superheated thus greatly conducing to economy. The flues through
which the heated gases pass are carried in horizontal channels under the bottom
in vertical or parallel tiers of horizontal channels in the sides;-in horizontal
channels under or over the roof lining and finally sometimes in descending channels
to the foot of the chimney and such channels may be formed of fire-brick fire-clay
cast or wrought metal or pipes of various sectional forms. Between the inner walls
or shell of the oven and the outer walls thereof we interpose a layer or layers of
wool slag, asbestos, or other suitable non-conducting material in order to prevent
loss of heat by conduction or radiation and to render the same economical in fuel
and effectual in working. The usual flue over the door is constructed with a
moveable door or valve thereto and dampers are fitted to the chimney and flues
where necessary. Our said improvements are applicable and adaptable to the
construction of ovens for cooking, baking bread, pastry, pottery, porcelain, art tiles,
and otherwise where definite and controllable degrees of heat are desirable or
necessary. And in order that our said Invention may be clearly understood
reference is hereby made to the accompanying Drawings in which similar letters
of reference indicate corresponding parts in the several figures: Fig: 1 is an
external front elevation of an oven constructed in accordance with our said
Invention. Fig: 2 is a transverse sectional elevation the left hand side thereof
being on the line E. F. of Fig: 3 and the right hand side thereof being on the
line C. D. of Fig 3.-Fig: 3 is a longitudinal sectional elevation of the oven.
Fig: 4 is a Plan partly of the top of the oven and partly on the line A. B. of Fig 3.
The burners a are arranged as shewn in Fig: 3 doors m are provided for lighting
the same
The heat arising from the combustion of the gas and air passes from the
combustion chamber c into the lower row of metallic tubes d. which are embedded
in sand. Under the floor of the oven a layer of sheet lead e. is laid to prevent

page_text: damp from rising.-Over this is laid a bed of fossil meal four inches thick as shewn
at f. Fig 3 and upon this is laid a bed of sand in which the lower row of metallic
flues d. are laid. These flues carry the heated gases from front to back and open
into the back flue g. This flue carries or conducts the heated products of com-
bustion to the upper row of metallic flues h. h. These upper flues are uncovered
.and their outward surfaces are in contact with the air in the oven. A portion of
the heat is utilised by the lower flues and passed to the floor of the oven These
tubes however being embedded in sand only pass a modified portion of the heat to
the floor of the oven reserving the remainder of the useful heat for absorption by
the air of the oven by means of the upper row of uncovered metallic tubes. By
:these means and modifications thereof we are enabled to arrange the distribution
of the heat to the top and bottom of the oven respectively as found desirable
according to the nature of the articles goods or materials to which the heat is
applied. The near ends of the upper metallic flues open into a transverse flue i. as
shewn in Fig: 3 and this flue opens into down-cast side flues which act as heat
traps and convey the residue of the products of combustion down to the foot of the
chimney. Dampers k. k. Fig: 1 control the currents in these flues. A cistern for
heating water is placed upon the oven to utilise waste heat. Air is allowed to
enter and traverse the flues . for the purpose of absorbing some of the waste heat.
This air is conducted to the space a. Fig: 3 where it mixes (in a highly heated
state) with the gas and therewith is burnt in the combustion chamber c.
doors m. m. Fig: 1 are for the purpose of lighting the burners. the doors n. n. are
for the purpose of regulating the cocks of the burners and the door o is for the
'purpose of regulating the admission of cold air to the regenerative flues.
The
Having thus particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we claim :-The use
and construction of improved smokeless ovens and the means and manner of
heating the same by the combustion of gas fuel formed and arranged substantially
as herein before described and shown on the Drawings.
In witness whereof I, the said William Henry Thompson on behalf of myself
and the said William Arden Crommelin, John Lees, and Henry Spain,
have hereunto set my hand and seal. this twenty first day of June in the
year of Our Lord One thousand eight hundred and eighty three.
WITT TAM HENRY THOMPSON