Improvements in Strainers for Straining Paper Pulp.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Strainers for Straining Paper Pulp.
I, HENRY JOHN ROGERS, of Lavington, Watford, in the County of Hertford,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object an improved form of strainer for straining
paper pulp and consists of a conical vat of cast iron or other suitable material
constructed either square, circular, octagonal or hexagonal in plan, and preferably
being deeper at one part of its lower circumferential area so that the heavy or
waste particles of the pulp will gravitate to that point for ultimate exit to the
auxiliary strainer. In the interior of this conical vat is placed a framework
of gunmetal or other suitable material corresponding in area and configuration
to the vat already discribed, a prescribed space being left between the inner cir-
cumference of the vat and the outer circumference of the said framework, into
which the pulp to be strained is admitted in any suitable manner but preferably
in such a manner that its course follows the circumference of the vat so that
the centrifugal action of the flow of the pulp will cause the heavy or waste
particles thereof to pass rather to the outside of the above area into which the
pulp is admitted, than to the inside. The said framework of gunmetal or other
suitable material is constructed of two or more horizontal rings, cylindrical,
octagonal or hexagonal or of other approved form joined together by vertical
bars between which bars are fixed by set screws or otherwise the plates through
which the pulp is to be strained, or V shaped grooves or slots may be planed in
the said vertical bars so that the plates, which are themselves conical in form
and may have corresponding V edges, may be forced into the said V grooves and
be held firmly therein without the aid of set screws. This is an important im-
provement in the construction of strainers as it enables the plates to be removed
in a very short time for washing up or for
changing sorts" or for any
other purpose.
i.
"
Fixed at the bottom of the vat and framework is a strong stand of large area
at its base to give rigidity to the strainer under action, and an outlet from
the space enclosed by the strainer plates (or "inner vat") is constructed to carry
away the strained pulp to the paper making machine. The whole of the above
parts of the strainer are stationary and the passage of the pulp through the
slits of the strainer plates is caused by a plunger of form corresponding to the
internal area of the framework containing the plates. This plunger is attached
to the framework supporting the plates by a diaphragm of rubber or other elastic
material and floats in the strained pulp, it is caused to rise and fall rapidly
therein by means of tappets or cams impinging on studs affixed to its upper
surface which after every contact between the cams and the studs depress the
plunger in the pulp the said plunger being as frequently raised by strong springs
which encircle guide rods fixed to the upper part of the vat, the effect of this
vibratory action being that every time the plunger is raised a vacuum is formed
which draws the pulp through the slits of the plates and every corresponding
depression of the plunger cleanses the slits ready for the next passage of pulp
through them. The cams or tappets may be actuated by a pulley-driven shaft in

page_text: the usual way or by other suitable means. In some cases the diaphragm may
be dispensed with and the passage of the pulp effected by means of the alternate
rising and falling of the plunger alone or there may be a diaphragm at the
bottom of the plunger, the plunger in that case being actuated from the bottom
instead of from the top in the same manner as already described. The great
advantages of a strainer constructed as above are:-.
1. The small area it occupies.
2. The small amount of power required to drive it.
3. The very considerably increased straining area and suction power in com-
parison with its corresponding size.
4. Its cleanliness, as no dirt or knots or hanks remain on the surface of the
plates.
5. The waste of the pulp being reduced to a minimum as the vat of the strainer
can be entirely emptied of its contents and
6. Its noiselessness.
Improvements in Strainers for Straining Paper Pulp.
I, HENRY JOHN ROGERS, of Lavington, Watford, in the County of Hertford,
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 has for its object an improved form of strainer for straining
paper pulp and consists of a conical vat a of cast iron or other suitable material
constructed either square oblong circular octagonal or hexagonal in plan, the
said vat being preferably deeper at one part so that the heavy or waste particles
of the pulp will gravitate to that point for ultimate exit to the auxiliary strainer, by
means of the outlet 6. In the interior of this conical vat is placed a frame-
work of gunmetal or other suitable material, corresponding in area and configura-
tion to the vat already described a space being left between the inner circum-
ference of the vat and the outer circumference of the said framework (when the
strainer is constructed of a circular form) into which the pulp to be strained is
admitted in any suitable manner, but preferably in such a manner that its course
follows the circumference of the vat so that the centrifugal action of the flow
of the pulp will cause the heavy or waste particles thereof to pass rather to the
outside of the above area into which the pulp is admitted, than to the inside.
The accompanying drawings shew the strainer made in accordance with this
invention of an oblong shape see Fig. 1 which represents the said strainer in
elevation Fig. 2 in plan and Figs. 3 and 4 in end elevation.
The said framework of gunmetal or other suitable material is constructed of
two or more vertical bars d joined at the top and bottom and supported by
studs and collars e between which bars are fixed by set screws or otherwise
the plates through which the pulp is to be strained or ✓ shaped grooves or
slots may be planed in the said vertical bars d so that the plates f which may
have corresponding V edges may be forced into the said V grooves and be held
firmly therein without the aid of set screws. This is an important improvement
in the construction of strainers as it enables the plates to be removed in a very
short time for "washing up" or for "changing sorts or for any other purpose,
but in some cases set screws may be used for fixing the plates if desirable.
"

page_text: Fixed at the bottom of the vat a and framework d is a strong stand h of large
area at its base to give rigidity to the strainer under action and an outlet i
from the space enclosed by the strainer plates (or "inner vat") is constructed to
carry away the strained pulp to the paper making machine.
The whole of the above parts of the strainer are stationary and the passage of
the pulp through the slits of the strainer plates is caused by a plunger j of
form corresponding to the internal area of the surface of the plates f. This
plunger is attached to the framework supporting the plates or to the plates
themselves by a diaphragm k of rubber or other elastic material and floats in the
strained pulp it is caused to rise and fall rapidly therein by means of tappets
or cams impringing on studs m which after every contact between the cams
and the studs raise the plunger in the pulp, the said plunger being as frequently
depressed by strong springs n which encircle guide rods o fixed to the upper part
of the vat a the effect of this vibratory action being that every time the plunger j
is raised a vacuum is formed which draws the pulp through the slits of the plates f
and every corresponding depression of the plunger cleanses the slits ready for the
next passage of pulp through them. The cams or tappets may be actuated by a
pulley driven shaft p in the usual way or by other suitable means.
In some
cases the diaphragm may be dispensed with and the passage of the pulp effected
by means of the alternate rising and falling of the plunger alone. Bends ŕ aro
placed at the end of the vat a to keep the pulp level therein.
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. The method of passing the pulp through the strainer plates f by means of
the plunger rising and falling in close proximity to the plate surface by means
of which the pulp is sucked through the plates f as described and illustrated.
2. The diaphragm k placed over the area between the plate surface f and the
said plunger to assist in forming the vacuum caused by the rise and fall of
the said plunger j.
Tatod this 94th 1 of Tannow in the won
Law 1900