AN IMPROVEMENT IN REMOVING THE SCALE OR DEPOSIT FROM TUBULAR FLUES OF STEAM BOILERS
Year: 1856

page_text: LETTERS PATENT to Robert Baird Lindsay, of Mill Wall Brewery, Poplar,
in the County of Middlesex, for the Invention of "AN IMPROVEMENT IN
REMOVING THE SCALE OR DEPOSIT FROM TUBULAR FLUES OF STEAM BOILERS."
Sealed the 10th October 1856, and dated the 12th April 1856.
PROVISIONAL SPECIFICATION left by the said Robert Baird Lindsay
at the Office of the Commissioners of Patents, with his Petition, on the
12th April 1856.
I, ROBERT BAIRD LINDSAY, of Mill Wall Brewery, Poplar, in the County
of Middlesex, do hereby declare the nature of the Invention for "AN
IMPROVEMENT IN REMOVING THE SCALE OR DEPOSIT FROM TUBULAR FLUES OF STEAM
BOILERS," to be as follows:-
This Invention has for its object an improvement in removing the scale or
deposit from tubular flues of steam boilers, and the Invention consists of
applying to this purpose highly heated air or steam. For this object, atmo-
spheric air (or it may be steam) when highly heated by any suitable apparatus,
such, for instance, as that used in obtaining hot blast or otherwise, or by
passing the same through a suitable fire, is caused to enter and fill the boiler,
and in some cases the tubular flues, by which means the scale or deposit will
be caused to crack and shell off, and it is desirable that the boiler and
tubular flues should at the commencement of the process be in the cold state.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Baird Lindsay in the Great Seal Patent Office on the
10th October 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
BAIRD LINDSAY, of Mill Wall Brewery, Poplar, in the County of Middlesex,
:send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of April, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Robert Baird Lindsay, Her special licence that I, the said Robert Baird
Lindsay, my executors, administrators, and assigns, or such others as I, the
said Robert Baird Lindsay, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 "AN IMPROVEMENT
IN REMOVING THE SCALE OR DEPOSIT FROM TUBULAR FLUES OF STEAM BOILERS,"
upon the condition (amongst others) that I, the said Robert Baird Lindsay, 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 per-
formed, 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 Robert Baird Lindsay, 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 thereof, that is to say:
This Invention has for its object an improvement in removing the scale or
deposit from the tubular flues' of steam boilers; and the Invention consists of
applying to this purpose highly heated air or steam. For this object atmo-
spheric air (or it may be steam) when highly heated by any suitable apparatus,
such, for instance, as that used in obtaining hot blast, or otherwise or by
passing the same through a suitable fire, is caused to enter and fill the boiler,
and in some cases the tubular flues, by which means the scale or deposit will
be caused to crack and shell off, and it is desirable that the boiler and tubular
flues should at the commencement of the process be in the cold state.

page_text: Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
The boiler being empty, and by preference quite cold, I force highly heated
steam into the boiler, so as to pervade it on all parts. For this purpose, I
prefer that the introduction should be as low down in the boiler as may be,
and to allow the heated air or steam to flow off at any opening or man-hole at
the bottom of the boiler, and from this opening or man-hole I make a commu-
nication with the chimney, which by causing a draft therein draws the cold air
through the tubes and cools them internally. The air I cause to be heated
in preference by forcing it through a fire contained in a furnace similar to a
cupola furnace, and communicating at the top with the interior of the boiler;
or it may be heated by passing it through heated pipes, and this is the method
which should be employed when steam is used, but steam will not (as when
using air) require a fan or other blowing apparatus for propelling it through
the heating apparatus and into the steam boiler which is to be cleansed. The
effect of thus introducing heated air or heated steam into a steam boiler will
be to cause the scale or deposit which is on the tubular flues to crack and
separate from the metal surfaces, and the boiler will thus be quickly cleansed;
the scale or deposit may then be removed from the interior of the boiler in the
usual manner. I have generally found that the scale or deposit separates
within twenty to thirty minutes; the time, however, will vary, depending on the
nature and extent of the scale.
In the case of locomotives engines, I find it advisable to admit a jet of steam
to the chimney while the operation is going on, to increase the current of cold
air through the tubes.
In witness whereof, I, the said Robert Baird Lindsay, have hereunto set
my hand and seal, this Third day of October, in the year of our Lord
One thousand eight hundred and fifty-six.
0 Witness,
GEO. PITT,
4, Old Square.
R. B. LINDSAY. (L.S.)