CERTAIN IMPROVEMENTS IN MUR CONSTRUCTION OF STEAM BOILERS
Year: 1860

page_text: LETTERS PATENT to Richard Pollit, of Bolton-le-Moors, in the County
of Lancaster, Boiler Maker, for the Invention of "CERTAIN IMPROVEMENTS
IN MUR CONSTRUCTION OF STEAM BOILERS."
Scaled the 28th December 1860, and dated the 9th July 1860.
PROVISIONAL SPECIFICATION left by the said Richard Pollit at the
Office of the Commissioners of Patents, with his Petition, on the
9th July 1860.
I, RICHARD POLLIT, of Bolton-le-Moors, in the County of Lancaster,
Boiler Maker, do hereby declare the nature of the said Invention for "CEB-
TAIN IMPROVEMENTS IN THE CONSTRUCTION OF STEAM BOILERS," to be as
follows:-
The object of my Invention is to obtain a large amount of effective heating
surface, a perfect combustion of the fuel, a good circulation in the water, a
inore equal expansion in the various parts of the boiler, and great strength.
The casing of my improved boiler is cylindrical, with flat or hemispherical
ends; the fire grates are placed in, one, two, or more flues, which are bent
downwards into a flue which conveys the products of combustion along the
bottom to the end of the boiler; they then enter into a double fluo which
conveys them towards the firing end of the boiler, and back again to the other
end; the products of combustion are then taken by flues all round the boiler,

page_text: and thence into the chimney. The above description refers to a boiler with
two fire flues, but it is capable of being modified. In order to increase the
combustion of the fuel, I connect the upper part of the firing flue near the
bridge to the atmosphere, by a pipe which serves as a stay, and is furnished
with a damper or regulating valve to vary the quantity of air admitted.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Pollit in the Great Seal Patent Office on the
9th January 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
POLLIT, of Bolton-le-Moors, in the County of Lancaster, Boiler Maker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of July, in the year of our Lord One
thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Richard Pollit, Her special licence that I, the said Richard Pollit, my exe-
cutors, administrators, and assigns, or such others as I, the said Richard
Pollit, 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 "CERTAIN IMPROVEMENTS
IN THE CONSTRUCTION OF STEAM BOILERS," upon the condition (amongst others)
that I, the said Richard Pollit, my executors or administrators, by an instru-
ment 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 within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Richard Pollit, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
The object of my Invention is to obtain a large amount of effective heating
surface, a perfect combustion of the fuel, a good circulation in the water. a
more equal expansion in the various parts of the boiler, and great strength.

page_text: The casing of my improved boiler is cylindrical, with flat or hemispherical
ends; the fire grates are placed in one, two, or more flues, which are bent
downwards into a flue which conveys the products of combustion along the
bottom to the end of the boiler; they then enter. into a double flue which
conveys them towards the firing end of the boiler, and back again to the
other end; the products of combustion are then taken by flues all around the
boiler, and thence into the chimney. The above description refers to a boiler
with two fire flues, but it is capable of being modified. In order to increase
the combustion of the fuel, I connect the upper part of the firing flue near the
bridge to the atmosphere, by a pipe which serves as a stay, and is furnished
with a damper or regulating valve to vary the quantity of air admitted.
And in order that my Invention may be fully understood and readily carried
into effect, I will proceed to describe the accompanying Sheet of Drawings,
reference being had to the figures and letters marked thereon.
Figure 1 is an elevation in section of my improved boiler and seating;
Figure 2 is a plan of the same; Figure 3 is a transverse section through A, B,
on Figure 2; and Figure 4 is another transverse section through C, D, on
Figure 2.
a is the outer shell or casing of the boiler; and b, b, the ends, which are
shewn flat, but may be hemispherical if preferred; c, c, are the fire grates,
which are placed in the flues d, d, as shewn in Figure 1; these flues are
bent downwards beyond the bridge, and are both in communication with the
flue f, which extends along the bottom of the boiler, and guides the products
of combustion to one end of the double flue g; this double flue extends within
the boiler to near the flues d, where it is bent back, and then opens into the
flue h, which is carried along the outside of the boiler to the firing end, then
under the boiler, and thence along the other side to the flue i, which commu-
nicates with the chimney. The double flue g is supported from the bottom of
the boiler by the stays j, and if desirable, it may be stayed to the rounded
ends of the flues d. The pipes k placed above the firing flues d, and the
pipes which are placed above the pipes k, are for the purpose of admitting
air beyond the bridge of the fire grate in order to increase the combustion of
the fuel. Each pipe is furnished with a damper or valve m, by which the
quantity of air admitted can be regulated at pleasure; the rods and levers for
opening and closing these regulating valves, can be worked by the attendant,
or they may be in communication with the firing doors to admit air when
the firing door is opened to supply the fuel. I wish to remark that I do not
limit myself to the use of two firing flues d, as a single firing flue, or more
than two, may be applied. I prefer however, the use of two flues, as the

page_text: fires can then be fed alternately, thereby ensuring a perfect combustion
of the fuel.
Having thus stated the nature of my Invention, and described the manner
of performing the same, I declare that I claim, the general arrangement of
the parts forming a steam boiler as herein-before described and shewn in the
Drawing, and the apparatus for admitting air to the flues d as described.
In witness whereof, I, the said Richard Pullit, have hereto set my hand
and seal, this Seventh day of January, in the year of our Lord One
thousand cight hundred and sixty-one.
RICHARD POLLIT. (L.B.)