AN IMPROVED MODE OF PRESERVING, OR PROTECTING FROM CORROSION WIRE WEBS AND STRAINER PLATES USED IN THE MANUFACTURE OF PAPER
Year: 1868

page_text: LETTERS PATENT to William Durham, of Currie, in the County of
Mid Lothian, North Britain, for the Invention of " AN IMPROVED MODE
OF PRESERVING, OR PROTECTING FROM CORROSION WIRE WEBS AND STRAINER
PLATES USED IN THE MANUFACTURE OF PAPER."
Sealed the 12th March 1869, and dated the 15th September 1868.
PROVISIONAL SPECIFICATION left by the said William Durham at
the Office of the Commissioners of Patents, with his Petition, on
the 15th September 1868.
I, WILLIAM DURHAM, of Currie, in the County of Mid Lothian, North
Britain, do hereby declare the nature of the said Invention of "An
IMPROVED MODE OF PRESERVING OR PROTECTING FROM CORROSION WIRE WEBS AND
STRAINER PLATES USED IN THE MANUFACTURE OF PAPER," to be as follows, that.
is to say :-
This Invention, which relates to the preservation or prevention from
corrosion of the wire webs and strainer plates used in machines employed
for the manufacture of paper, consists in connecting a piece of metal
which is electro-positive to the wire webs or strainer plates. The piece
of metal is immersed wholly or partly in the fluid pulp, and connected
by a strip of copper to the wire webs or strainer plates to be preserved..

page_text: By this arrangement an electric current passes from the electro-posative
metal through the pulp to the wire or plate to be preserved, and the
effect is to direct all the chemical action upon the electro-positive metal,
while the wire or plate being electro-negative is completely preserved
from corrosion by the chemical substances in the pulp. The metal
which it is preferred to use as the electro-positive is zinc, and to
effectually preserve the wire the zinc plate should have a surface not
less than a tenth part or thereabouts of the surface of the wire covered
at one time by pulp; the plate may be suspended in the pulp as it issues.
from the vat or otherwise conveniently placed. A strip of copper is
attached to the zinc plate; the other end of the copper is fastened to
the brass of the breast roll of the wire web, by which means complete
metallic connection is made between the wire and the zinc. To prescrve
the strainer plates strips of zinc may be placed round and fixed to the
strainer frame, if metallic, so as to dip into the pulp as it is passing
through.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Durham in the Great Seal Patent Office
on the 13th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
DURHAM, of Currie, in the County of Mid Lothian, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Hor
Letters Patent, bearing date the Fifteenth day of September, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Durham, Her special licence
that I, the said William Durham, my executors, administrators, and
assigns, or such others as I, the said William Durham, 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 torm
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 IMPROVED
MODE OF PRESERVING OR PROTECTING FROM CORROSION WIRE WEBS AND STRAINER
PLATES USED IN THE MANUFACTURE OF PAPER," upon the condition (amongst

page_text: others) that 1, the said William Durham, my executors or adminis-
trators, 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 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 William Durham, 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, that is to say :-
The object of this Invention is the preservation of or prevention from
corrosion of the wire webs and strainer plates used in the machines above
mentioned, and consists in the following arrangements of construc-
tion thereof, that is to say, to protect a machine or web wire the
following plan is adopted: - A plate of zinc or other metal clectro-
positive to the wire is immersed in the pulp as ncar the wire as
convenient, and connected by strips of copper or other metal to the
framework of the machinc, so that complete metallic contact is esta-
blished between the wire and the plate of zinc. The plate of zinc must
be supported free from contact with any metallic part of the machine,
except through the copper strips above mentioned. By this arrangement
an electric current passes from the electro-positive metal through the
pulp to the wire or plate to be preserved, and the effect is to direct all
the chemical action upon the electro-positive metal, while the wire or
plate being electro-negative is completely preserved from corrosion by
the chemical substances in the pulp. The metal which it is preferred
to use as the electro-positive is zinc (amalgamated if necessary), and to
effectually preserve the wire the zinc plate should have a surface not
less than a tenth part or thereabouts of the surface of the wire covered
at one time by pulp. The plate may be suspended in the pulp as it issues
from the vat or otherwise conveniently placed. A strip of copper is
attached to the zinc plate; the other end of the copper is fastened to the
brass of the breast roll of the wire web, by which means complete or
metallic connection is made between the wire and the zinc. Rollers of
zinc may be substituted for the copper rolls on which the wire runs.
but this is not recommended, the zinc plate for many reasons being
preferable in most cases. To protect the strainer plates a sunilar

page_text: arrangement of a zinc plate or other metal may be used, or strips or
bands of zinc may be fastened in the strainer frame in such a position
as to be always covered with pulp while the strainer is at work, care
being taken that there is close contact between the zinc and the strainer
plate.
Having thus particularly described the nature of my said Invention,
and stated in what manner the same is to be performed or put in practice
in order that the manner of performing or putting in practice the same
may be fully and particularly described and ascertained in and by these
Presents, I have hereunto annexed the accompanying Drawings or
Diagrams, which I now proceed to describe.
DESCRIPTION OF THE DRAWINGS OR DIAGRAMS.
In these diagrams, A denotes the machine or web wire; B denotes the
plate of zince or other metal positive to the wire; C, the connecting
strips of copper or other metal; D denotes the means of supporting free
from contact, except through the strips.
Having now particularly described and ascertained the nature of the
said Invention, and in what manner the same is to be performed, I
hereby declare that I claim the Invention the nature whereof is
described in the outset of this Specification by the words which precede
the words "Description of the Drawings," it being understood that I do
not claim the details shown by the Drawings and described with
reference thereto, except as constituent parts of the arrangement herein
described.
In witness whereof, I, the said William Durham, have hereunto set
my hand and seal, this Tenth day of March, in the year of our
Lord One thousand eight hundred and sixty-nine.
Witness,
MATTHEW THAIN,
Balerno Mills,
Currie.
WILLIAM DURHAM. (L.S.)