IMPROVEMENTS IN AND APPARATUS FOR REMOVING ENCRUSTA- TION FROM STEAM BOILERS, SALT PANS, AND OTHER SIMILAR APPARATUS, AND PREVENTING SEDIMENT ADHERING THERETO
Year: 1876

page_text: LETTERS PATENT to Israel Swindells, of Warrington, in the County of
Lancaster, and Robert Lancaster, of Widnes, in the same County, for the
Invention of "IMPROVEMENTS IN AND APPARATUS FOR REMOVING ENCRUSTA-
TION FROM STEAM BOILERS, SALT PANS, AND OTHER SIMILAR APPARATUS, AND
PREVENTING SEDIMENT ADHERING THERETO."
Sealed the 19th May 1876, and dated the 3rd March 1876.
PROVISIONAL SPECIFICATION left by the said Israel Swindells and Robert
Lancaster at the Office of the Commissioners of Patents on the 3rd March
1876.
ISRAEL SWINDELLS, of Warrington, in the County of Lancaster, and ROBERT
LANCASTER, of Widnes, in the same County. "IMPROVEMENTS IN AND APPARATUS
FOR REMOVING ENCRUSTATION FROM STEAM BOILERS, SALT PANS, AND
SIMILAR APPARATUS, AND PREVENTING SEDIMENT ADHERING THERETO.
"
OTHER
We place a galvanic apparatus inside a steam boiler, and from which we carry a
copper wire to a series of (by preference) zinc plates suitably disposed in the water
of the boiler, and connected together by copper wires, or we use such series of zinc
plates so connected together without a galvanic battery, and thus in either case we
produce a galvanic action between the plates of the boiler and such zinc plates, and
so remove encrustation or prevent sediment adhering thereto. This apparatus and
inethod of treatment is equally applicable for the same purpose to salt pans and
other similar evaporating or boiling apparatus.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Israel Swindells and Robert Lancaster in the Great Seal Patent Office
on the 2nd September 1876.
ISRAEL SWINDELLS, of Warrington, in the County of Lancaster, and ROBERT
LANCASTER, of Widnes, in the same County. "IMPROVEMENTS IN AND APPARATUS
FOR REMOVING ENCRUSTATION FROM STEAM BOILERS, SALT PANS, AND OTHER
SIMILAR APPARATUS, AND PREVENTING SEDIMENT ADHERING THERETO."
CD 211
"

page_text: We place a series of zinc plates inside a steam boiler suitably disposed beneath
the surface of the water, and connected together by copper wire, and thus we
produce a galvanic action between the plates of the boiler and such zinc plates in
order to remove encrustation or prevent sediment adhering thereto. This apparatus
and method of treatment is equally applicable for the same purpose to salt pans
and other similar evaporating or boiling apparatus.
In carrying out our Invention, for instance, as applied to a double-flued steam
boiler of 30 feet length and 7 feet 6 inches diameter, we take, say nine plates or
blocks of zinc weighing about 14 lbs. each, and place three of such plates or blocks
at equal distances apart on the top of each metallic flue inside the boiler, and the
other three we lay at the bottom of the inside of the boiler. We then produce a
metallic contact between such plates or blocks by connnecting or linking them
together by preference in the form of a continuous chain by copper wire, say No. 7
wire gauge; and one extremity of this wire being screwed we pass the same
through any convenient part of the shell of the boiler to the outer atmosphere,
making a steam-tight joint by the application of a pair of lock nuts in the ordinary
manner. The boiler is thus constituted a galvanic battery, and at the same time
the zinc blocks, having an affinity for the acids contained in the water, a chemical
action takes places, forming, for instance, in the case of lime, sulphate of zinc, and
precipitating the lime as an oxide at the bottom of the boiler, in which state it has
little or no tendency to adhere to the metallic plates. The combined galvanic and
chemical action thus obtained is found useful not only in removing existing
encrustation from steam boilers, salt pans, and other similar apparatus to which the
Invention is applied, but also in preventing sediment adhering to such apparatus.
Although in our Provisional Specification we mentioned the use of a galvanic
battery in conjunction with a series of zinc plates for the purposes of this Invention
we have since ascertained that no such battery is requisite.
Having thus particularly described and ascertained the nature of this our said
Invention, together with the best methods with which we are acquainted for
carrying the same into practical effect, we wish it to be understood that we do not
confine ourselves to the number, size, or shape of the zinc plates or blocks herein-
before described, as the same will vary according to the size of the boiler and nature
of the water or other liquid being evaporated.
We wish it further to be understood that we are aware that zinc plates have
been suspended in certain classes of steam boilors to counteract certain evils arising
from surface condensation feed water, and we therefore make no claim to zinc
plates so suspended, but what we do claim is the use and application of a series of
zine plates or blocks connected together by copper wire, and entirely submerged
in the liquid undergoing evaporation, as and for the purposes herein-before
described.
In witness whereof, we, the said Israel Swindells and Robert Lancaster, have
hereunto set our hands and seals, this First day of September, in the year
of our Lord 1876.
Witness,
JOHN G. WILSON,
Patent Agent,
71, Market St.,
Manchester.
ISRAEL SWINDELLS. (L.S.)
ROBT. LANCASTER.
(L.S.)