IMPROVEMENTS IN GENERATING STEAM AND EVAPORATING LIQUIDS
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME I, FREDERIC
LESNARD, of Keppel Street, in the County of Middlesex, Engineer, send
greeting.
9
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-ninth day of April, in the eighth year of Her
reign, did, for Herself, Iler heirs and successors, give and grant unto me;
the said Frederic Lesuard, Her especial license; full power, sole privilege
and authority, that I, the said Frederic Lesuard, my executors, admini-
strators, and assigns, and such others as I, the said Frederic Lesnard, my
executors, administrators, or assigns, should at any time" agree with, and no
others, from time to time and at all times during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
England, Wales, the Town of Berwick-upon-Tweed, and in all Her Majesty's
Colonies and Plantations abroad, and in the Islands of Jersey, Guernsey,
Alderney, Sark, and Man, my Invention of "IMPROVEMENTS IN GENERATING STEAM
AND EVAPORATING LIQUIDS;" in which said Letters Patent is contained a proviso
obliging me, the said Frederic Lesnard, by an instrument in writing under my
hand and seal, particularly to describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, and to cause the
same to be inrolled in Her Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part recited
Letters Patent, as in and by. the same, reference being thereunto had, will
more fully and at large appear.
.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Frederic Lesnard, do hereby declare that the nature of my said Invention and
the manner in which the same is to be performed, is particularly described and
ascertained in and by the following description thereof, reference being had to
the Drawings hereunto annexed and to the letters and figures marked thereon
(that is to say):
These improvements in generating steam and evaporating liquids consist in
employing a bath of oil or other fatty matter as the heating medium by which
water shall be evaporated or converted into steam. In ordinary steam boilers
the extended surfaces of the furnace and its flues with which the water is
brought in contact being exposed to the immediate action of the fire, it
sometimes happens, owing to the inattention of the engineer or from
some other cause, when the water becomes low, that little besides
steam is left in the boiler, at which time there is great probability
of accident either of explosion or collapsing in consequence of the boiler
becoming red hot. The object of these improvements, therefore, is to
òbviate this evil, by employing a bath of fluid matter between the heated surface
of the boiler and the water which shall be capable of communicating the
required heat without exposing the water to the action of the heated metallic
surfaces of the furnace or its flues. For this purpose I charge the boiler with
fish oil or other fatty matter, which will retain a much greater quantity of
heat before it boils than water will; and when the oil or other fatty matter
has been raised to a suitably high temperature I then pass jets of water
through the fatty fluid, which water in its passage will take up the heat and
immediately flash into steam. These fatty matters, which are insoluble in
water are capable of being heated to such a temperature as to evaporize water
at from 212 to 320 degrees Fahrenheit, without being themselves decomposed.
They may even be raised to a higher temperature than this, as the decompo-
sition of fatty substances does not take place until they reach the boiling point,
which ranges very much above that of water.
The manner in which I propose to apply this Invention to boilers for gene-
rating steam is shewn in the accompanying Drawings, of which Fig. 1 is a
longitudinal section of a steam boiler taken vertically through the furnace and
part of its flue; Fig. 2 represents a double boiler, the portion A being in trans-
verse section taken in the vertical line Y, Z, of Fig. 1, and the portion B being
an end elevation of the front of the boiler; Fig. 3, is a horizontal represen-
tation of the double boiler, the portion B shewing its upper external surface,
the portion A being a section taken horizontally in the line W, X. of Fig. 1,
the similar letters of reference pointing out the same parts in all the figures.

page_text: The boiler may be constructed of plates of metal bent and rivetted
together in the ordinary way of making steam boilers, but I do not limit
myself to any particular form, provided such form be adopted as may be
capable of carrying out my improved mode of generating steam, of which
that shewn in the Drawings is one. a, a, are the furnaces furnished with fire
grates b, b, and ash pits c, c, below; d, d, are the feeding doors for introducing
the fuel; e, e, flaps for covering the mouths of the ash pits, in order to damp the
fire, but which should be left open when the boiler is in full operation, to
admit air for supporting the combustion of the fuel; f.f.f, zigzag or contorted
flues passing from the furnaces through and round the boiler, from which the
smoke and vapours emitted by the combustion are discharged into the
chimney g; the lower parts of the boiler at h, h, h, h, may be occupied with
water, and upon the top of this I fill up the boiler as at i, i, i, i, i, to
about the level shewn in the Drawing, with fish oil or other oily or
fatty matters capable of being rendered fluid; k, k, are long flat tubes,
extending in horizontal directions through the boilers, from end to end,
below the surface of the oil i, i; these tubes are to contain water, sup-
plied by a force pump 1, or otherwise, which water is conducted through
pipes m, m, communicating with the flat tubes k, k; and the tubes are per-
forated with a multitude of small holes, through which the water may escape.
The only matter, i, i, i, in the boiler being heated to a high degree of tem-
perature by the furnace, the pump 7 is then made to force water through the
pipes m, m, into the tubes k, k, from whence it will pass in a multitude of jets
through the apertures into the oily fluid, and there taking up the heat will
immediately flash into steam, and rise to the upper part of the boiler n, n, and
into the steam chamber p, from whence the steam will proceed by the pipe q
to work a steam engine, or for any other use. In order to prevent the oily
matter i, i, flowing principally to one side of the boiler, which might occa-
sionally be the case on shipboard, a vertical partition plate r, r, is placed along
the boiler, but it must have openings as at 8, s, s, to allow of the free passage of
the steam to the steam chamber. It is the safety valve, and u is the man-hole
for gaining access to the interior of the boiler, when it may be necessary to
clean it.
Having now described the manner in which I generate steam and
evaporate liquors, by throwing jets of water into or upon heated fatty matters,
I desire it to be understood that I do not intend to confine myself to any
particular form of boiler, provided that the construction is such as will admit
of water being in jets brought in contact with the heated oil or other fatty fluid
matter, so as to generate steam instanter. And I do not intend to confine

page_text: myself to the position of the jet tubes as described below the surface of the
heated oil, as an effect of the same kind might be attained by throwing jets
of water upon the surface of the heated oil, but I prefer the tube to be
immersed.
Inrolled the same. Twenty-ninth day of October, in the year above I
written..