I- PROVEMENTS IN STEAM GENERATORS
Year: 1866

page_text: LETTERS PATENT to William Alexander Lyttle, Officer of the Secretary's
Department, General Post Office, London, for the Invention of "I-
PROVEMENTS IN STEAM GENERATORS."
Sealed the 26th October 1866, and dated the 18th May 1866.
PROVISIONAL SPECIFICATION left by the said William Alexander Lyttle
at the Office of the Commissioners of Patents, with his Petition, on the
18th May 1866.
I, WILLIAM ALEXANDER LYTTLE, Officer of the Secretary's Department,
General Post Office, London, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM GENERATORS," to be as follows:-
I I prepare the fire-box of the steam boiler so that it can be rendered air-
tight in the manner described in the Specification of my Patent of the 10th
July 1865, Number 1820 (upon which this Invention is intended as an
improvement), and I fit the smoke box with a trap plate or valve which can
either be opened to give free passage to the gases from the furnace, or shut
down and weighted by a spring or weight so as to open only upon the exertion
of a certain force. In the next place I adapt to the furnace a blowing
apparatus consisting of a centrifugal or other pump, as described in my
aforesaid Patent.

page_text: To work this engine the trap or valve in the chimney should first be
opened as well as the fire-door so as to enable the fire to be lighted and the
steam got up by a free draught of air; these passages should then be closed
and the blowing apparatus set to work as described in the aforesaid Patent;
the fuel would thus be burned by compressed air, and the bot gases would be
so far retarded in their transit along the flues as to be more thoroughly filtered
of their heat than at present. With the exception that the waste gases are
not allowed to mix with the steam in the boiler, all the other arrangements
described in my aforesaid Specification can, if desired, be applied to this
steam generator, and any existing fuel, whether solid or liquid, can be used.
In the use of liquid fuel with this steam generator it may be found
desirable to adopt a modification of the apparatus now sold by perfumers under
the name of "the atomiser," which consists of two glass tubes placed at right
angles so that a blast of air through one tube rushes across the end of the
other, and by thus causing a vacuum in the latter shall draw up and scatter
in the form of a fine vapour any liquid in which the vacuum tube may be
immersed. By thus arranging a number of vacuum tubes in the blast of the
blowing apparatus of my steam generator it is evident that coal oil or other
liquid fuel may be comminuated and so burned in the fire-box in admixture
with the supply of air. This atomising arrangement may be placed at any
desirable part of the fire-box, such as at one or more of the points at which
the air tubes may be made to enter the fire-box under my Patent, No. 1820
of 1865.
I claim, 1st, the construction of a steam generator for any purpose in such
a way that at one time its fuel shall be burned by air compressed as herein-
before described, and at another time can be used on the ordinary plan by
having its fuel burned with a free draught.
I claim, 2ndly, for the use of steam generators constructed under this
Patent the several details herein-before described although I do not confine
myself to those arrangements in carrying this Iuvention into execution.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed.
by the said William Alexander Lyttle in the Great Seal Patent Office
on the 17th November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ALEXANDER LYTTLE, Officer of the Secretary's Department, General Post
Office, London, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Alexander Lyttle, Her special licence that I, the said William
Alexander Lyttle, my executors, administrators, and assigns, or such others
as I, the said William Alexander Lyttle, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN STEAM GENERATORS," upon the condition (amongst
others) that I, the said William Alexander Lyttle, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office withiu
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Alexander Lyttle do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :-
I prepare the fire-box or furnace of the steam boiler so that it can be
rendered air-tight in the manner described in the Specification of my Patent
of the 10th of July 1865, Number 1820, upon which this Invention is
intended as an improvement, and I fit the smoke box or chimney flue with a
trap plate or valve, or both, which can either be opened to give free passage
to the gases from the furnace, or shut down and weighted by a spring or
weight so as to open only upon the exertion of a certain force. Otherwise,
the chimney may be furnished with a sluice or other valve so fitted that it can
be readily opened or shut at any moment by the fireman, and also, in addition,
with a yielding valve, which when the sluice or other aforesaid valve is shut,
may come into action as a vent for the smoke gases at a certain regular
pressure. In the next place I adapt to the furnace a blowing apparatus
consisting of a centrifugal or other pump, as described in my aforesaid
Patent.
In order to work an engine under this plan the trap or valve in the
chimney should first be opened as well as the outer fire-door, so as to enable

page_text: the fire to be thoroughly lighted and the steam got up by a free draught of
air; these passages should then be closed and the blowing apparatus set to
work as described in the aforesaid Patent; the fuel would thus be burned
by compressed air, and the hot gases would be so far retarded in their transit
along the flues as to be more thoroughly filtered of their heat than at present.
With the exception that the waste gases of combustion are not allowed to mix
with the steam in the boiler, all the other arrangements described in my afore-
said Patent Specification can, if desired, be applied to this steam generator,
and any existing fuel, whether solid or liquid, can be used.
In the use of liquid fuel with this steam generator it may be found desirable
to adopt a modification of the apparatus now known amongst perfumers under
the name of the "atomiser," which consists of two glass tubes placed at
right angles, so that a blast of air through one tube rushes across the end of
the other, and by thus causing a vacuum in the latter draws up and scatters
in the form of a fine vapour any liquid in which the vacuum tube may be
immersed. By thus arranging a number of vacuum tubes in the blast of the
blowing apparatus of my steam generator it is evident that coal oil or other
liquid fuel may be comminuated and so burned in the furnace in admixture
with the supply of air. This atomising arrangement may be placed at any
desirable part of the furnace, such as at one or more of the points at which
the air tubes may be made to enter the furnace under my Patent, No. 1820
of 1865.
The traps or valve in the chimney may be placed at any desired height, and
the interior of the chimney below the trap or valve may be lined with vertical
tubes connected together at the top and also at the bottom, and having a pipe
communicating at their top with the blowing apparatus and at their bottom
with the fire; by this means the cold air would become heated in its passage
down the chimney on its way to the fire and a further economical absorption
of the waste heat would be effected while gaining the advantage of a hot
blast. Instead, however, of placing the yielding valve in question in the
chimney up which the smoke passes when a free draught is used, a second
chimney may be provided. The former chimney should be provided with a
sluice or other convenient valve for closing it when the latter chimney is about
to be brought into requisition. The latter chimney may either be arranged so
that it shall be opened and closed at its bottom by the fireman with a sluice or
other valve separately, or in connexion with the foregoing valve in the first
chimney; or it may be fitted at its bottom with a clack or similarly acting
valve, so that when the first or free-diaught chimney is closed the pressure
caused by the blowing apparatus will open the clack, and the smoke or hot

page_text: gases will thus become "shunted" up the second chimney. The latter
chimney may be not only lined with the vertical air tubes herein-before
described, but it may be so far occupied with such tubes that the hot gases on
their upward passage may be almost completely robbed of their heat through
coming in contact with a larger extent of cooling surface. It may be
preferable, however, to construct the second chimney like a multitubular
boiler placed on end, the hot gases ascending the tubes, and the cold air
descending through the spaces which would in a boiler be occupied with water
and steam. Instead of lining the inner surface of either chimney with air
tubes as described, a metallic casing may be used as an inside lining of the
flue, so that the cold air may pass down from the top to the bottom of tho
chimney between these two casings, a sufficient space between them being left
for the purpose. The yielding valve, by means of which the pressure in the
atmosphere of the furnace is maintained and regulated, may be either at tho
top of the second chimney, or the clack or other valve at the bottom of the
second chimney, already referred to, may be made to perform the function of
regulating the pressure.
In the case of marine engine boilers, or wherever there are a number of
separate furnaces attached to one chimney, it will be necessary that there
should be fitted to the smoke passage of each the sluice or other valve already
described, and also that when two chimneys are used for the purposes herein.
before described the furnaces should have two distinct flues of connexion with
the chimneys, each furnace being provided at its point of connexion to such
flues with the several valves for regulating and guiding the hot gases, as
already above specified; by this means one furnace or set of furnaces may
be worked with a free draught at any time without interfering with the
others. A suitable valve must of course be provided for cutting off the branch
blast when the free air is admitted to any particular fire. The action of the
latter valve and that of the valve closing the chimney may be so connected
that one movement shall work both; thus, that the fireman in moving the
lever or rod for the purpose of opening the chimney to a free draught shall by
the same movement shut off the blast, and vice versa.
Having now specified the nature of my Invention, and some of the best
means kuown to me for carrying it into effect, I claim,-
Isily, the construction of a steam generator for any purpose in such a way
that at one time its fuel shall be burnt with air supplied under pressure,
whether heated or not, as herein-before described, and at another time it can
be used on the ordinary plan by having its fuel burnt with a free draught
of air.

page_text: I claim, 2ndly, for the use of steam generators constructed under this
Patent, the several novel details herein-before described, although I do
not confine myself to those arrangements in carrying this Invention into
execution.
In witness whereof, I, the said William Alexander Lyttle, have hereunto
set my hand and seal, this Seventeenth day of November, in the year
of our Lord One thousand eight hundred and sixty-six.
W. A. LYTTLE. (L.S.)