IMPROVEMENTS IN THE GENERATION OF STEAK AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
28th August 1871.-A communication from abroad by Augustus
Collingridge, Master Mariner, and William Stephen, Barrister-
at-Law, both of Dunkerque, France.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE GENERATION OF STEAK AND IN THE
APPARATUS EMPLOYED THEREIN," a communication to me from abroad by
Augustus Collingridge, Master Mariner, and William Stephen, Barrister-
at-Law, both of Dunkerque, France, to be as follows :-
-
Hitherto the generation of steam has been usually effected by the
application of fire to the external surface of a boiler containing the
main body of water or other fluid from which the steam is to be raised.
Various contrivances are in use with the view of exposing the greatest
possible area of surface to the action of ignited fuel. But the mode
of construction and of disposition of boilers and furnaces alike preclude

page_text: "
the entire utilization of the total amount of heat as ropresented by the
quantity of fuel consumed. Hence arises the fact that although in
theory the consumption of a given weight of fuel composed of certain
ingredients should convert a fixed quantity of water into steam the
result is seldom attained in practico, a large per-centage varying with
special circumstances requiring to be allowed for waste of caloric.
In order to effect the more rapid and economical generation of steam
a small closed vessel is used constructed in copper or in malleable iron
.or in other suitable material of sufficient strength to resist a pressure of
at least two atmospheres, such vessel being furnished with two tubes or :
pipes, one end of each pipe communicating with the interior of the
vessel. Each pipe is fitted with a self-acting valve so constructed to
operate that the valve of one pipe allows fluid to flow inwards only into
the interior of the closed vessel, and that the valve of the other pipe
allows of the fluid when greatly dilated with heat or converted into
steam to flow outwards only.
The dimensions of the closed vessel and its outward form and the
length of the pipes and their diameter, and whether such pipes should
be straight or curved, must be governed by circumstances, but by
preference the closed vessel is constructed in the form of an inverted
cone, and the diameter of the pipes in ordinary cases is fixed at
one-fourth of the greatest diameter of the closed vessel to which they
are annexed.
"
.
The top or cover of the vessel should allow of being removed or of
being securely fastened down at the will of the operator. The entire ?
apparatus should be steam-tight in every joint. A safety' valve may be
added with advantage to the cover if raising steam from any admixture
of water and volatile matter such as ether or alcohol.
To work the apparatus the closed vessel should be charged with a
small portion of fluid analogous to the main body of fluid requiring 3
to be heated or converted into steam, the cover fixed securely on the
pipes so arranged that the orifices of the extremities furthest from the
vessel lead into the main body of fluid, penetrating deep below the
surface. Active heat being applied to the exterior of the closed vessel
steam is rapidly generated and escapes into the main body of fluid 8
through the pipe with the valve opening outwards. The immediate
result is the formation of a vacuum inside the vessel. "This vacuum in

page_text: its turn is quickly filled by an influx of a portion of the main body of
fluid, which rushes in with extreme velocity through the pipe with the
valve opening inwards only. This portion of fluid is converted into
steam and escapes in that form as before, leaving a vacuum again to be
refilled from the main body.
The successive processes of the convertion of fluid into steam, the
formation of a vaccum, the repletion of such vacuum, and the generation
of steam are reproduced with great celerity by means of the combinations
in the apparatus described. A constant circulation of fluid is ensured,
whereby every particle of fluid is successively brought in contact with
the internal surface of the heated sides of the covered vessel within
which a vaccum has been produced.
It is well known that the diminution of atmospheric pressure has
often been effected by air pumps and other mechanical contrivances
fitted to closed boilers with the view of heating fluids under diminished
atmospheric pressure, but any vacuum produced by such methods as are
now in use is only partial, whereas the vacuum produced by means of
the combinations in the apparatus above described is very complete and
perfect, and consequently fuel and time are proportionately economised.