IMPROVEMENTS IN STEAM. BOILERS
Year: 1861

page_text: LETTERS PATENT to Ludwig William Roddewig, of Sheffield; in the
County of York, Engineer, for the Invention of "IMPROVEMENTS IN STEAM.
BOILERS." A communication from abroad by Frederick Schmidt, of.
Hagen, in the Kingdom of Prussia.
Sealed the 5th November 1861, and dated the 10th May 1861.
PROVISIONAL SPECIFICATION left by the said Ludwig William Roddewig
at the Office of the Commissioners of Patents, with his Petition, on the
10th May 1861.
I, LUDWIG WILLIAM RODDEWIG, of Sheffield, in the County of York,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN STEAM BOILERS," (being a communication to me from abroad by
Frederick Schmidt, of Hagen, in the Kingdom of Prussia,) to be as
follows:-
This Invention consists in the construction of boilers with an inner and an
outer chamber, the inner one of which is in more immediate contact with the
heat of the furnace, and is surrounded by the outer chamber, the water level
in the inner chamber being considerably lower than usual, and that in the
outer chamber being considerably higher than usual.
than usual. There is a pipe com-
municating from the upper part of the outer chamber to the lower part of the
inner chamber, through which the water passes from the former to the latter
when it has attained a sufficiently high level in the former. By this arrange-

page_text: ment the water, being fed into the outer chamber, is made to circulate around
the inner chamber in a direction contrary to that in which the heat passes
along the flue around the outer chamber from the furnace to the chimney.
By this arrangement also the sediment is caused to be collected in that part
of the outer chamber which does not come in contact with the fire.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Ludwig William Roddewig in the Great Seal Patent Office
on the 7th November 1861.
TO ALL TO WHOM THESE. PRESENTS SHALL COME, I, LUDWIG
WILLIAM RODDEWIG, of Sheffield, in the County of York, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of May, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Ludwig William Roddewig, Her special license that I, the said Ludwig
William Roddewig, my executors, administrators, and assigns, or such others.
as I, the said Ludwig William Roddewig, 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 BOILERS," being a communication from abroad by
Frederick Schmidt, of Hagen, in, the Kingdom of Prussia, upon the condition
(amongst others), that, I, the said Ludwig William Roddewig, by an, instru
ment in writing, under, my hand and seal, 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, immediately after the date of the
said, Letters, Patent.
NOW KNOW YE, that I, the said Ludwig William Roddewig, do hereby
declare the, nature of the 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 Drawings hereunto annexed,
and to the letters, and figures marked thereon (that is to say) :-
:-
This Invention of "Improvements in Steam Boilers" consists in the con-

page_text: struction of boilers with an inner and an outer chamber, the inner one of
which is in more immediate contact with the heat of the furnace and is
surrounded by the outer chamber, the water level in the inner chamber being
considerably lower than usual, and that in the outer chamber being consider-
ably higher than usual. There is a pipe communicating from the upper part
of the outer chamber to the lower part of the inner chamber through which
the water passes-from the former to the latter when it has attained a suffi-
ciently high level in the former. By this arrangement the water, being fed
into the outer chamber, is made to circulate around the inner chamber in a
direction contrary to that in which the heat passes along the flue around the
outer chamber from the furnace to the chimney. By this arrangement also
the sediment is caused to be collected in that part of the outer chamber which
does not come in contact with the fire.
Having thus stated the nature of the said Invention, I will proceed to
describe more particularly in what manner the same is to be performed by
the aid of the accompanying Drawings, in which are represented the improve-
ments above referred to.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a cross section of a boiler; Fig. 2 is a longitudinal section; and
Fig. 3 is a horizontal section of the same.
A is the brickwork or seating of the boiler; B, the furnace; C, the inner
chamber, formed by means of plates, as shewn; D, the outer chamber, which
entirely surrounds the inner chamber; E is the pipe through which water is
fed into the outer chamber D; F is the pipe leading from the upper part of
the outer chamber D to the lower part of the inner chamber C, through which
water passes from the former into the latter when it has attained a sufficiently
high level in the former; G, G, are the ordinary flues of the boiler. The
necessary floats and valves for regulating the supply of water to the chambers
and other matters of detail common to boilers are not shewn. On water being
admitted into the outer chamber D through the pipe E it will pass in the
direction shewn by the arrows in Fig. 3, and will fill the chamber up to the
level of the pipe F, which is considerably above the ordinary level. The
water, on being still fed into the chamber, will flow through the pipe Finto
the inner chamber C, which is in immediate contact with the heat of the
furnace B. In this chamber C the water level is considerably lower than
usual, and the principal part of the steam is generated, the outer chamber D
being used for heating the water as it is fed into the boiler preparatory to its
evaporation. Both the chambers C and D are open at the top and com-

page_text: municate with the steam space in the upper part of the boiler. The arrows
in Fig. 2 indicate the passage of the beat from the furnace along the flues,
which it will be seen is in a direction opposite to that of the water and along the
.outer chamber D. The sediment will be deposited principally in the sides of
the outer chamber Dat the lowest parts thereof, which parts are out of contact
with the fire. It will be readily understood that the water in the outer
chamber D will not sink much lower than the pipe F, and the side flues come
up to this line within a few inches, so that there is no danger of heating the
plates by which the chambers are formed. The level of water in the inner
chamber C may sink a good deal before it exposes the plates.
Having thus described the nature of the said Invention, communicated to
me as aforesaid, I would remark that the chambers may be formed in a
different manner from that shewn in the Drawing, and so as to vary their
relative proportions, and the boiler may be of various forms; but I hereby
declare that what I claim as of the Invention is, the construction of boilers
with an inner and an outer chamber, with arrangements by which the water
level is considerably lower than usual in the inner chamber, and considerably
higher than usual in the outer chamber, as herein-before described.
In witness whereof, I, the said Ludwig William Roddewig, have here-
unto set my hand and seal, the Sixth day of November, in the year of
our Lord One thousand eight hundred and sixty-one.
L. W. RODDEWIG. (L.S.)