Improvements in or relating to Cooking by Steam.
Year: 1897

page_text: Date of Application, 24th Mar., 1897
PROVISIONAL SPECIFICATION.
Improvements in or relating to Cooking by Steam.
I, HUBERT HIGGINS, of 4, Trinity Street, Cambridge, in the County of Cam-
bridge, Demonstrator of Anatomy to Cambridge University, do hereby declare
the nature of this invention to be as follows:-
The object of this invention is to enable cooking processes to be safely and
conveniently carried out by the utilisation of steam, primarily produced for other
purposes.
Great difficulty has hitherto been experienced in employing steam, generated,
for instance to work the engines of a steam ship, or for manufacturing or other
purposes, for culinary processes owing to the high pressures usually employed,
and the rapid condensation caused by passing it into a cold chamber.
The apparatus employed in carrying out this invention consists of a cooking
chamber and superheater.
The cooking chamber consists of an inner chamber, of suitable size and material,
provided with shelves, and is completely surrounded by an outer chamber of
somewhat larger size, forming what is commonly known as a jacket. Proper
provision is made for doors and necessary fittings, and both inner chamber and
jacket are connected with the superheater. The jacket is likewise provided with
a cock to carry off the water of condensation, and may be suitably lagged.
The superheater may be of any convenient form and heated in any suitable
manner, but arranged so that the whole or a part of it may be used at will for the
purpose of regulating the temperature of the steam. It receives its steam by
means of a pipe either direct from the boiler or from any convenient steam pipe
forming part of the main power plant of the building, factory or steam ship etc.
in which it is placed, the supply being regulated by a reducing or other valve.
When employing the apparatus, a current of steam, reduced to substantially
atmospheric pressure is first circulated through the jacket, so as to raise the cook-
ing chamber to a temperature that will obviate condensation of the steam intro-
duced into the cooking chamber. When this has taken place a current of steam
is passed through the cooking chamber itself till the process is completed. This
steam may have passed through whole or part of the superheater or can have been
derived directly from the boiler, the jacket meanwhile being maintained, or
maintaining itself at such a temperature as to entirely prevent any condensation
of steam within the cooking chamber.
Dated this 94th dor of Hamah
100%
BOULT & WADE,
Agents for the Applicant.

page_text: Improvements in or relating to Cooking by Steam.
I, Hubert HIGGINS, of 4, Trinity Street, Cambridge, in the County of Cam-
bridge, Demonstrator of Anatomy to Cambridge University, 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:-
The object of this invention is to enable cooking processes to be safely and
conveniently carried out by the utilisation of steam primarily produced for other
purposes, whereby in the same apparatus, a constant current of steam may be
employed at a temperature of about 100° C, or at any desired temperature above
that point, the steam in all cases being kept substantially at atmospheric pressure,
whatever may be the pressure at the source from whence it is obtained.
Great difficulty has hitherto been experienced in employing steam, generated,
for instance to work, the engines of a steam ship, or for manufacturing or other
purposes, for culinary processes owing to the high pressures usually employed,
and the rapid condensation caused by passing it into a cold chamber.
The apparatus employed in carrying out this invention comprises a chamber
and a steam superheater, with the necessary heating apparatus, connected with
the source of supply through the medium of a reducing valve.
The accompanying drawing shows diagrammatically a chamber and super-
heater with its connecting valves constructed according to this invention.
The chamber consists of an inner chamber A preferably completely surrounded
by an outer chamber B of somewhat larger size forming what is commonly known
as a jacket.
.
The chamber A may be of any suitable size and material, and provided with
shelves or other fittings according to the purpose for which it is intended, such
as cooking, drying or sterilizing. Proper provision is made for doors and it is
connected by the pipe D with the superheater C, a pipe A' being likewise provided
for carrying away the steam.
The superheater may be of any ordinary construction that gives a prolonged
travel to the steam and is provided with openings, controlled by valves, at various
portions of its length, so that the steam can be withdrawn at will after a greater
or less exposure to the heating medium. A convenient form consists of a coil,
as shown at C, receiving its steam through a pipe controlled by a reducing
valve C, and stop valve C, and having openings controlled by valves C³, C³,
C4, C5, into the pipe D connected with the chamber A.
The coil may be of any convenient form, either helical as shown or consisting of
zig-zag or parallel tubes united by return bends, the essential point being the
faculty of controlling the length of travel of the steam when exposed to the heat-
ing medium.
Four connections are shown as a convenient number, but more or less may
be used according to the range of temperature which may be desired to be em-
ployed in the chamber.
The superheater may be heated in any convenient manner, either directly by
a gas or other furnace, or by the products of combustion from the generator fur-
nace.
The supply of steam to the superheater may be obtained from generators
primarily intended for other purposes, such as the main boilers of a factory or of

page_text: a steam ship. The supply may be drawn either directly from the boiler, or from
the main or other stean pipe, the connection being made in any convenient manner,
a reducing valve C6 constructed in a manner well known being provided in
addition to the stop-valve C', so as to reduce the high pressure steam to atmos-
pheric pressure before its entry into the superheater.
In order to prevent condensation of steam within the chamber A, it may be
provided with a jacket B, heated either (a) by passing through it the whole or
a sufficient proportion of the combustion gases from the heating apparatus of
the boiler or superheater, or (b) by the direct application of heat to the exterior
of the jacket, or (c) by passing a current of steam from the superheater through
the jacket. The necessary pipes, dampers, etc., are provided on each case so that
the temperature is under control and the jacket is preferably lagged.
The pipe D may be connected direct with the steam supply by a valve D',
so that if desired steam may be passed through the chamber without first passing
through the superheater. If the steam is obtained from a high pressure supply
this connection must be supplied with a reducing valve, so that only low pressure
steam is admitted to the chamber.
All necessary gauges, pyrometers, and fittings are provided for properly work-
ing and controlling the apparatus.
Two or more chambers may be used and the steam passed from one to the
other, a superheater being provided between each chamber if desired.
When in operation the jacket B is first heated so as to warm the chamber A and
prevent condensation on the initial admission of steam therein, and this heating
may be continued throughout tlie operation if desired.
The steam is admitted to the superheater C through the valves Co; C¹ being
reduced to substantially atmospheric pressure by the operation of the reducing
valve C. One of the cocks C, C, C+, C, is then opened and a continuous current
of steam passes into the chamber A through the pipe D, escaping therefrom by
the valve A. According as the temperature is required to be raised or lowered
the steam is allowed to travel through a greater or less length of the superheater.
If a temperature is required only slightly in excess of 100° C, the cock C is opened
and the steam passes through only a short portion of the superheater before enter-
ing the chamber A through the pipe D. To raise the temperature the cock C³
is opened and C3 closed, giving the steam a longer exposure to the heating medium,
the highest temperature being obtained by passing the steam through the whole
length of the superheater by opening the cock C, the others being closed.
this means whilst the initial pressure of the steam forming the supply may be
high, the pressure in the chamber is maintained at substantially atmospheric
pressure, whilst a perfect control of the temperature within the chamber is
obtained.
By
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is: -
1. In steam cooking apparatus the use of a superheater which enables the
temperature of the cooking steam to be varied without thereby necessitating a.
change of pressure and which is provided with a reducing valve.
2. In steam cooking apparatus the use of steam at fixed (and preferably atmos-
pheric) pressure but at varying temperature such temperature being obtained
by means of a superheater and regulated as herein described.
8. In steam cooking apparatus the combination of a jacketted chamber and a
superheater capable of regulation and provided with a reducing valve substan-
tially as described.
4. In steam cooking apparatus a superheater such as C provided with a reducing
valve and branches controlled by valves substantially as and for the purpose
described.

page_text: 5. The compiete steam cooking apparatus substantially as described and illus-
trated.
1008
BOULT & WADE,
Agents for the Applicant.