IMPROVEMENTS IN AND APPLICABLE TO STEAM BOILERS
Year: 1874

page_text: LETTERS PATENT to William Cunningham Lang, of Liverpool, in the
County of Lancaster, Consulting Engineer, for the Invention of
65 IMPROVEMENTS IN AND APPLICABLE TO STEAM BOILERS,'
Sealed the 18th June 1875, and dated the 19th December 1874.
PROVISIONAL SPECIFICATION loft by the said William Cunningham
Lang at the Office of the Commissioners of Patents, with his
Petition, on the 19th December 1874.
I, WILLIAM CUNNINGHAM LANG, of Liverpool, in the County of
Lancaster, Consulting Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN AND APPLICABLE TO STEAM BOILERS," to be
as follows:-
-
The object of my Invention is to prevent the leakage, corrosion,
pitting, and deterioration of steam boilers (more especially marine steam
boilers) which have taken place, and are probably due to unequal expan-
sion and contraction of the boiler shells when in use by reason of the
water near the bottom of the boilers being at a much lower temperature
than that over the fire-places.
For the above purposes I cause the water to circulate from the lowest
portion of the boiler through the shell, thence upwards into the water

page_text: space at a higher level or into the steam space. The circulation of tho
water is ensured either by heat, as in causing such water to pass through
hollow fire-bars or pipes alongside or through the fire-places, or by fans
or other mechanical appliances.
To ensure that the water shall be caused to circulate from the bottom
of the boiler to a higher level, that is, to a position where there is a
higher temperature, I attach to the lowest portion of the boiler one or
more water boxes, from which the water is drawn off. By drawing off
the comparatively cold water from the sides of the boxes the lower
portions of such boxes will serve as collectors for sediment or mud,
which can be removed from time to time.
To prevent the water in the boiler descending in a straight column
into the boxes I interpose one or more baffle plates over the opening of
such boxes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Cunningham Lang in the Great Seal Patent
Office on the 19th June 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CUNNINGHAM LANG, of Liverpool, in the County of Lancaster, Con-
sulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of December, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Cunningham Lang, Her special
licence that I, the said William Cunningham Lang, my executors, admi-
nistrators, and assigns, or such others as I, the said William Cunning-
ham Lang, 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 Inven-
tion for "IMPROVEMENTS IN AND APPLICABLE TO STEAM BOILERS," upon the
condition (amongst others) that I, the said William Cunningham Lang,
my executors or administrators, by an instrument in writing under my,

page_text: 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 William Cunningham Lang, 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, reference being had to the accompanying
Sheet of illustrative Drawings and to the figures and letters marked
thereon, that is to say :-
.
The object of my Invention is to prevent the leakage, corrosion,
pitting, and deterioration of steam boilers (more especially marine steam
boilers) which have taken place, and are probably due to unequal expan-
sion and contraction of the boiler shells when in use by reason of the
water near the bottom of the boilers being at a much lower temperature
than that over the fire-places.
For the above purposes I cause the water to circulate from the lowest
portion of the boiler through the shell, thence upwards into the water
space at a higher level or into the steam space. The circulation of the
water is ensured either by heat, as in causing such water to pass through
hollow fire-bars or pipes alongside or through the fire-places, or by fans
or other mechanical appliances.
To ensure that the water shall be caused to circulate from the bottom
of the boiler to a higher level, that is, to a position where there is a
higher temperature, I attach to the lowest portion of the boiler one or
more water boxes, from which the water is drawn off. By drawing off
the comparatively cold water from the sides of the boxes the lower
portions of such boxes will serve as collectors for sediment or mud,
which can be removed from time to time.
To prevent the water in the boiler descending in a straight column
into the boxes I sometimes interpose one or more baffle plates over tho
opening of such box.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a view partly in section and partly in elevation illustrative of

page_text: b, furnaces; c, box attached to the lowest part of boiler; e, circulation
pipes connected to the hollow fire-bars f;.g, stop valve; h, cock through
which mud and sediment in c can be drawn off.
Fig. 2 is a sectional view of a further modification. i, boiler; j, water
box; k, baffle plate; 1, circulation pipe. The circulation through is
assisted by a pump or suitable means.
Figs. 3 and 4 are sectional side. and end views showing my improve-
ments applied to a double ended four-furnaced boiler. The arrangement
is the same as in Fig. 1.
The same letters apply to similar parts.
The circulation pipes e¹ are by preference caused to enter the boiler at
a higher level than shown on the Drawings.
When the circulation is caused by means of hollow fire-bars check
valves may be placed in the circulation pipes below such fire-bars.
Having now described and ascertained the nature of my said Inven-
tion so that others will be enabled to carry my improvements into effect,
I claim,-
First. Causing the water to circulate from the lowest part of the boiler,
substantially as and for the purposes set forth.
Second. The means and apparatus for causing the circulation of water a
in steam boilers, constructed, arranged, and combined substantially as
described and illustrated for the purposes set forth.
In witness whereof, I, the said William Cunningham Lang, have
hereunto set my hand and seal, the Eighteenth day of June,
in the year of our Lord One thousand eight hundred and seventy- 2
five
J. JOHNSON,
Patent Office,
4, Clayton Square,
Liverpool.
W. C. LANG. (L.S.)