Improvements in the Construction of Strainers Used for Straining Pulp in the Manufacture of Paper and Paper Boards, and for Preparing "Half Stuff" from Wood, Straw, and other Materials for Straining, Clearing, or Separating the Sheaves and other Impurities from the some PROVISIONAL SPECIFICATION. STRERS PU IN THE MANUFACTURE OF PAPER PAPER BOARDS AND FOR PREPARING " FF FROM WOOD STRAW AND OTHER MATERIALS FOR STRAINING CLEARING OR SEPARATING THE SHEAVES AND OTHER IMPURITIES FROM THE SAME
Year: 1884

page_text: Improvements in the Construction of Strainers Used for Straining
Pulp in the Manufacture of Paper and Paper Boards, and
for Preparing "Half Stuff" from Wood, Straw, and other
Materials for Straining, Clearing, or Separating the Sheaves
and other Impurities from the some
PROVISIONAL SPECIFICATION.
I GEORGE TIDCOMBE Junior of Watford Iron Works Watford in the County
of Herts Paper Makers' Engineer do hereby declare the nature of my said
Invention for IMPROVEMENTS IN THE CONSTRUCTION OF STRAINERS USED FOR
STRAINING PULP IN THE MANUFACTURE OF PAPER AND PAPER BOARDS AND
FOR PREPARING "HALF STUFF FROM WOOD STRAW AND OTHER MATERIALS
FOR STRAINING CLEARING OR SEPARATING THE SHEAVES AND OTHER IMPURITIES
FROM THE SAME, to be as follows:-
33
This Invention relates to certain improvements in the construction of strainers
used for straining pulp in the manufacture of paper and paper boards and for
preparing half stuff from wood straw and other materials for straining clearing
or separating the sheaves and other impurities, from the same the object being to
prevent the accumulation of strings clots and lumps and to remove all sheaves
and other kinds of impurities left in strainers so as also to pass a greater quantity
of good pulp through a given strainer surface in a given time; and this I effect
as follows:-
In the construction of flat strainers I employ a travelling cleanser working upon
the surface of the plates this cleanser having a series of doctor strips or thin
cleanser edges attached to a travelling band carried on pulleys.
For the purpose of working this doctor cleanser accurately I form one end of
the strainer into a bay, lip or dam the side and edge of which is equidistant
radially from the contre of one of the pulleys at that end of the strainer so that
the travelling doctor strips may regularly carry the coarse matter and impurities
into the bay lip or dam. This bay or reservoir is partly or entirely surrounded
by a fine wire gauze or strainer surface forming in itself with the pulp contained
therein a filter or drainer and is surrounded by a trough which conveys the
extracted fluid to the "back water" of the paper making machine with which
back water it mixes and becomes used up in the paper being made or passes on to
a saveall and is treated by ordinary means whilst the solid portion and impurities
are removed and dealt with according to their value; at the bottom of the bay is
Din li

page_text: a pair of squeezing rollers through which the removed portions from the cleanser
may be passed.
Ordinary cleansers, scrapers, or brushes acting upon strainer plates are irregular
in their effect because in their backward and forward passage over the slits of the
strainer plates they usually cover too many slits longitudinally in the course of
their operation. I obviate this defect by working my doctor cleanser edges across
the slits thereby presenting only a thin edge across them.
The number of cleansers which I use are equally distributed so that an equal
result is produced by the straining plates. For the purpose of working this
strainer I adapt the driving motions underneath such strainers as follows:
==
I employ knuckle joints as described in my former Patent for strainers N° 1908
dated 21 April 1882 or an arrangement of vertical springs acted upon by a crank
or cam where a reciprocating motion is required for slow speeds and an oval chuck
motion or direct acting balanced cranks for high speeds.
Dated this Ninth day of Ion 188.1

page_text: I GEORGE TIDCOMBE, Junior, of Watford Iron Works Watford, in the County
of Herts, Paper Makers Engineer do hereby declare the nature of my said
Invention for IMPROVEMENTS IN THE CONSTRUCTION OF STRAINERS USED FOR
STRAINING PULP IN THE MANUFACTURE OF PAPER AND PAPER BOARDS AND
PREPARING HALF STUFF FROM WOOD, STRAW AND OTHER MATERIALS FOR
STRAINING AND CLEARING OR SEPARATING THE SHEAVES AND OTHER IMPURITIES
FROM THE SAME and in what manner the same is to be performed, to bo
particularly described and ascertained in and by the following statement :—
"
This Invention relates to certain improvements in the construction of strainers
used for straining pulp in the manufacture of paper and paper boards and for
preparing half stuff from wood, straw and other materials, for straining, clearing
or separating the sheaves and other impurities from the same the object being to
provent the accumulation of strings, clots and lumps upon the strainer surface in
the flow of the stuff and to remove all sheaves and other kinds of impurities left
in strainers so as also to pass a greater quantity of good pulp through a given
strainer surface in a given time.
To obtain the best effect with an auxiliary strainer it is necessary to have a
large quantity of the flow continually running over the strainer surface with
sufficient force to wash the knots and impurities away which quantity has to bo
relifted. I obtain the requisite force of flow and avoid this excessive lifting of
such a quantity of stuff as well as the cost of working an auxiliary.strainer by
this Invention.
In Fig. 1 of the Drawings is shown the construction of a flat strainer with this
Invention applied; A is a travelling cleanser working upon the surface of the
strainer plates a this cleanser having a series of doctor strips A¹, or thin cleanser
edges attached to travelling band A, carried on pulleys B, and I form one end
(shown to the left in the Drawing) of the strainer into an upwardly extending
lip C, and bay D, the side and edge of which lip C, is equidistant radially from
the centre of one of the pulleys at that end of the strainer; so that the travelling
doctor strips A', may regularly carry the coarse matter and impurities up the
lip C, and into the bay D. This bay or reservoir D, is perforated and partly or
entirely surrounded by a fine wire gauze or strainer surface d, forming in itself
with the pulp contained therein a filter or drainer and is surrounded by a trough E,
which convoys the extracted fluid to the backwater of the paper making machine
with which backwater it mixes and becomes used up in the pulp for the paper
being made or passes to a saveall and is treated by ordinary means whilst the solid
portion and impurities are removed and dealt with according to their value. At
the bottom of the bay a pair of squeezing rollers may be provided through which
the removed portions from the cleanser may be passed. The number of cleansers
which I use are equally distributed on the band A, so that an equal result is
produced in the flow and by tho straining plates.
Fig. 14, shows in plan a portion of bay D, fitted transversely with perforated
or slitted division plates d¹, or frames of wire gauze so that a further area of
straining surface will be provided for the knots and lumps, which can be removed
and cleansed leaving the cakes of refuse matter behind. The perforated slitted or
wire gauze division plates can be readily removed so as to cleanse them during and
without stopping the working of the strainer. Fig. 2, shows section of a travelling
doctor strip which I employ forming in itself by its serrations, or angular corru-
gations f, a comb, or collector and each groove of which acts as a receptacle or
holder for the knots which would otherwise slip away. This form of cleanser need

page_text: not be the width of the strainer because each groove serration or corrugation
serves as a holder and secures the knots over that part of the plate a, on which it
travels and the good stuff will be left behind and pass through the plates a. These
doctors A¹, are of an elastic material or of any material soft enough not to injure
the plates, vulcanized rubber is. convenient.
Fig. 24, is a transverse view of the strainer plates a, travelling band A, doctors A¹,
and means for securing the doctors to the band A. For very long fibres I use a
combing doctor A², to comb the fibres away, as shown in Fig. 3, of such form that
the liquid portions may pass between or round the sides and these are made of a
similar material as above explained, or of metal softer than the plates a, so as not
to injure them. The carriages or bearings which carry the travelling cleansers are
mounted on a light framework fixed to the strainer framing with adjustable
bearings for adjusting the tension of the band vertically and lengthwise and so
that the said cleansers can be readily unfixed and replaced in their entirety and the
whole be adjusted in position.
I prefer to drive the underneath part of the strainer by the knuckle joint motion
explained in my former Patent N° 1908 dated 20th April 1882 and driven by
central double balanced crank as shown in Fig. 1 or I may use vertical steel blade
springs instead.
The Drawing Fig. 1 shows at G the ordinary method of leading the strained
stuff from the middle of the bottom of the strainer but it may be led out at the
end X or at the side Y thereby not reducing the suctional area of the bottom G¹
but giving an equal suction under the whole surface of the plates a.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is =
Firstly. In a strainer for straining pulp the curved end or lip C and bay D,
combined with the travelling doctor cleansers as herein described for effecting the
flow of the stuff and for discharging the knots lumps and accumulations of the
flow up and over the curved end C into the bay D as and for the purpose herein
set forth and shown by the Drawings.
Secondly. The strainer as herein described and shown by the Drawings having
in combination with the travelling doctor cleansers and the curved lip and bay,
the movablo framework and adjustable bearings for carrying and setting the
travelling cleansers as herein specified.
... nnu. JT1001