Improvements in Apparatus for Straining Paper Pulp.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Straining Paper Pulp.
I, JOHN WHITE, of the Firm of James Bertram and Son, Limited, Leith Walk
Foundry, in the City of Edinburgh, Engineer, do hereby declare the nature of
this invention to be as follows;-
This invention relates to pulp straining apparatus in which a rocking, tilting
or oscillating motion is imparted to the strainer plates through which the pulp
flows. In such apparatus as hitherto constructed, and as exemplified in the
specification of my Patent No. 17022 of 1891, the oscillating motion is generally
imparted to the vat containing the pulp and in which the strainer plates are fixed.
According to my present invention the main frame with the vat is made
stationary and secured to the sole plate or floor whilst the strainer plates are
carried in a framing which is suspended or supported in the vat and on the main
frame, and has a slow rocking, tilting or oscillating motion inparted to it. This
arrangement has the advantage of allowing of the framing carrying the strainer
plates being readily removed for cleaning or for changing the plates, whilst the
pulsating diaphragm having no longer to rock with the vat, may be operated by
any of the usual mechanical devices without risk of applying undue strain to the
flexible webs connecting it to the vat.
The vat, which may be of rectangular, circular or other shape and is formed
at the upper part of the stationary framing, has a deep channel or well formed
all round its outer edge or outwith the pulsating diaphragm or vibrating bottom
which is attached by the usual flexible webs to the inner wall of the channel.
Over the vat is placed the oscillating frame carrying the strainer plates the said
frame being of a shape corresponding with that of the vat, and being formed with
downwardly projecting sides or side plates which dip into the channel formed
round the vat. The oscillating frame may be suspended by links or carried by
knife edge bearings or trunnions at the upper part of the stationary framing and
above the strainer plates, or it may be supported at the lower edge of any of the
depending sides or elsewhere at or below the level of the strainer plates, but in
each case so that it is free to be rocked, tilted, swung or oscillated regularly
or intermittently in order to effect the required wash of the pulp across the
strainer plates. The mechanism for imparting the rocking, swinging, tilting or
oscillating motion to the frame with the strainer plates is preferably situated out-
with the vat but it may be carried through the vat or the channel around it. The
oscillating frame is connected by a flexible passage to the usual discharge box
which is secured to the side or end of the vat.
In the operation of the apparatus the stuff from the sand tables is fed into the
vat and flows into the side channel or well, around the dipping sides of the oscil-
lating frame to the upper side of the pulsating diaphragm and thence upwards
through the slits of the strainer plates and by the connecting passage to the
discharge box. The floating refuse matter cannot pass the dipping sides of the
oscillating frame, and thus never reaches the strainer plates, whilst the heavy

page_text: matter sinks to the bottom of the channel or well, (which acts as a trap) and may
be run to the auxiliary strainer through openings provided with cocks, piston
valves or like devices.
The slow oscillating motion imparted to the frame carrying the strainer plates
effectually prevents the good stuff settling in the channel or well, which latter in
conjunction with the dipping edges of the oscillating frame also ensures that the
motion of the pulsating diaphragm will send the pulp through the plates instead
of upwards around them.
The direction of flow of the pulp may however be reversed, that is to say, the
stuff may be led directly on to the upper surface of the plates and flow through
the slits in them into the vat below and thence through the channel or well to the
delivery box.
1
100
T
0
1
1000
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents, 62, Saint Vincent Street, Glasgow,
Agent for the Applicant.
I, JOIN WHITE, of the Firm of James Bertram and Son, Limited, Leith Walk
Foundry, in the City of Edinburgh, Engineer, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:
This invention relates to pulp-straining apparatus in which a rocking, tilting,
or oscillating motion is imparted to the strainer plates through which the puly
flows. In such apparatus as hitherto constructed the oscillating motion is
generally imparted to the vat containing the pulp and in which the strainer plates
are fixed.
The invention is illustrated by the accompanying drawings, in which Figure 1
is a longitudinal vertical section; Figure 2 a plan, and Figure 3 a transverse
vertical section. Figures 4, and 5 are transverse vertical sections of two slightly
modified forms of the invention, and Figure 6 a part longitudinal section of yet
another form.
According to my present invention the main frame A, with the vat A¹, is made
stationary and secured to the sole-plate B or floor, while the strainer plates are
carried in a framing D, which is suspended or supported in the vat and on the
main frame and has a slow rocking, tilting, or oscillating motion imparted to it.
This arrangement has the advantage of allowing of the framing D, carrying the
strainer plates C, being readily removed for cleaning or for changing the plates C,
while the pulsating diaphragm A2, having no longer to rock with the vat A', may
be operated by any of the usual mechanical devices without risk of applying
undue strain to the flexible webs E, connecting it to the vat.
The vat A', which may be of rectangular, circular or other shape and is formed
at the upper part of the stationary framing A, has a deep channel or well A³
formed all around its outer edge or without the pulsating diaphragm or vibrating
bottom A3, which is attached by the usual flexible webs E to the inner wall of the
channel A³. The deep narrow channel A³ is advantageous for several reasons,
e.g., it provides a trap without requiring a large body of material therein, as

page_text: would be the case if the floor A² were at or near the level of the bottom of the
channel A3 and the inner walls of the channels omitted. Over the vat is placed
the oscillating frame D, before referred to, carrying the strainer plates C, the
said frame D being of a shape corresponding with that of the vat A and being
formed with downwardly-projecting sides or side plates D', which dip into the
channel A", formed around the vat A¹. The oscillating frame 1) may be suspended
by links or carried by knife-edge bearings or trunnions F at the upper part of the
stationary framing A and above the strainer plates C, or it may be supported at
the lower edge of any of the depending sides or elsewhere at or below the level
of the strainer plates C, but in each case so that it is free to be rotated, tilted,
swung or oscillated regularly or intermittently in order to effect the required
wash of the pulp across the strainer plates.
The mechanism for imparting the rocking, swinging, tilting, or oscillating
motion to the frame D with the strainer plates C is preferably situated without the
vat A¹ and consists, as shown, of a rotating shaft I, carrying a cam J, which acts
on rollers K¹, carried on a connecting rod K, but may be carried through the rat
or the channel around it. The oscillating frame D is connected by flexible pas-
sages G forming canals which carry over the stuff from the oscillating frame D
to the usual discharge box H, which is secured to the side or end of the vat A¹.
The passages G, which are preferably made of rubber, leather, or similar
material, are flexible, yielding, or movable in such manner as to maintain their
operative position notwithstanding the oscillating motion of frame 1 which sup-
ports one end of said passages, the other end of said passages being supported on
a fixed part-namely, the vat A¹.
In the operation of the apparatus the stuff from the sand tables is fed into the
vat A1 and A20 and flows into the side channel or well A3, around the dipping sides
of the oscillating frame to the upper side of the pulsating diaphragm A2, and
thence upward through the slits of the strainer plates C and by the connecting
passage to the discharge box H. The floating refuse matter cannot pass the
dipping sides of the oscillating frame, and thus never reaches the strainer plates C,
while the heavy matter sinks to the bottom of the channel or well A3 (which acts
as a trap) and may be run to the auxiliary strainer through openings provided
with cocks, piston valves, or like devices. The slow oscillating motion imparted
to the frame D, carrying the strainer plates C, effectually prevents the good stuff
settling in, the channel or well A³, which latter, in conjunction with the dipping
edges D¹ of the oscillating frame D, also insures that the motion of the pulsating
diaphragm A2 will send the pulp through the plates C instead of upward around
them. The direction of flow of the pulp may, however, be reversed that is to
say, the stuff may be led directly on to the upper surface of the plates C and
flow through the slits in them into the vat A₁ below and thence through the
channel or well A to the delivery box H. In such a case the passages Gare
dispensed with and connection made direct between the vat A¹ and the delivery
box, as shown at Figure 6.
Instead of providing a pulsating diaphragm to form the bottom of the vat A¹
the bottom may, as shown at Fig. 4, he inflexible, and the framing D, carrying
the strainer plates C, besides having the oscillating motion imparted to it in the
manner already described, may be further reciprocated vertically by means of
connecting-rods L, at the upper ends of which the framing D is centred, these
rods being guided in bushes O and actuated at the lower ends by a cam M on a
rotating shaft N.
In the modification illustrated by Figure 5, the framing D carrying the strainer
plates is suspended at both ends from cams of eccentrics Q working in conjunction
with adjustable stops P, P, secured in the sides of the vat A'. The action
in this case is as follows;-As the cams or eccentrics Q revolve the frame D is
moved vertically and from side to side of the normal centre line and on the latter
movements taking place the sides of the frame I will come in contact with the
stops P', P, and so give the frame D the necessary tilt or oscillation. Should the

page_text: adjustable stops P, P, be moved out of contact with the sides of the frame D,
the motion of said frame D will follow the path of the cams or eccentrics Q.
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
·
1. In a pulp strainer the combination with the stationary main frame and vat
of a strainer plate carrying frame pivoted thereon and mechanism for imparting
a rocking, tilting, swinging or oscillating motion to said frame upon its pivot,
substantially as described.
2. In a pulp strainer the combination with a stationary main frame and vat
having a well or channel formed around it and extending below the bottom of the
vat, of a strainer plate-carrying frame pivoted to the main frame and having down-
wardly-projecting sides or side plates dipping into said well and also extending
below the bottom of the vat, substantially as described.
3. In a pulp strainer the combination of a stationary main vat, a vibratory
bottom for said vat, the vat having a channel formed around it, a strainer plate-
carrying frame pivotally supported in said vat and downwardly-projecting plates
dipping into the channel and extending below the bottom of the vat.
4. In a pulp strainer the combination of a stationary main vat, a vibratory
bottom for said vat having a channel formed around it extending below the
bottom of the vat, flexible webs E connecting the bottom to the inner wall of
said channel, a strainer plate-carrying frame pivotally supported in said vat, and
downwardly-projecting plates dipping into the channel.
5. In a pulp strainer the combination of a stationary main vat, a vibratory
bottom, the vat having a channel formed around it, a strainer plate-carrying
frame pivotally supported in said vat a discharge-box, and passages between the
strainer carrying frame and the discharge-box so arranged as to allow movement
of the strainer frame supporting one end of such passage, while the support of the
other end of the passage remains stationary.
Doted th 1141.
ex
1000
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents, 62, Saint Vincent Street, Glasgow,
Agent for the Applicant.