Improvements in Connection with the Pulp Strainers of Paper Making Machines, the same being Applicable to Paper Pulp Strainers Generally.
Year: 1888

page_text: Date of Application, 28th July, 1888
Complete Specification Left, 9th Jan., 1889
Complete Specification Accepted, 23rd Feb., 1889
PROVISIONAL SPECIFICATION.
Improvements in Connection with the Pulp Strainers of Paper
Making Machines, the same being Applicable to Paper Pulp
Strainers Generally.
I. WILLIAM DICKSON GROZIER of Bowling, in the County of Dumbarton, North
Britain, Paper Mill Manager do hereby declare the nature of this invention to be as
follows:-
This Invention, which relates to improvements in connection with the construction
and working of strainers for straining pulp in paper making machines or for straining
pulp in strainers separate from or not connected with paper making machines, has for
its object to generally increase the efficiency of such strainers.
The Invention consists in providing one or more openings of sufficient size to allow
an influx of air into the strainer during the straining operations so that the amount of
vacuum in the strainer is diminished or less than has been used in the operation of
pulp straining as hitherto practised. The quantity of air admitted into the strainer
varies with the quantity of pulp being strained. -
A convenient arrangement of providing the openings for the admission of air is to
This may be
keep a portion of the slits or cuts in the knotter plates uncovered.
effected by placing one or more slips or frames of wood, metal or other material upon
the knotter plates standing up a sufficient height above the layer of pulp to prevent it
flowing over the said portions of the slits on which the said slips or frames are
situated ; or it may be effected by making one or more openings of sufficient size in
the ends or sides of the strainers; and it may also be effected by passing air through
one or more pipes leading up through the bottom of the vat to the underside of the
strainer plates.
Dated this 97th day of July 1888.
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Petitioner's Agent.

page_text: Improvements in Connection with the Pulp Strainers of Paper
Making Machines, the same being Applicable to Paper Pulp
Strainers Generally.
I, WILLIAM DICKSON GROZIER of Bowling, in the County of Dumbarton, North
Britain, Paper Mill Manager 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 :-
My Invention, which relates to improvements in connection with the construction
and working of strainers for straining pulp in paper making machines or for straining
pulp in strainers separate from or not connected with paper making machines, has for
its object to generally increase the efficiency of such strainers.
My Invention consists in providing one or more openings of sufficient size to allow
an influx of air into the strainer during the straining operations so that the amount of
vacuum in the strainer is diminished or less than has been used in the operation of
pulp straining as hitherto practised. The quantity of air admitted into the strainer
varies with the quantity of pulp being strained.
My Invention may be carried out in several ways for example, by means of one or
more adjustable valves fixed either in the strainer plates or at the sides or ends of the
strainer, whilst another convenient arrangement of providing the openings for the
admission of air is to keep a portion of the slits or cuts in the knotter plates uncovered.
This may be effected by placing one or more slips or frames of wood, metal or other
material upon the knotter plates standing up a sufficient height above the layer of
pulp to prevent it flowing over the said portions of the slits on which the said slips or
frames are situated; or it may be effected by making one or more openings of
sufficient size in the ends or sides of the strainer and it may also be effected by
passing air through one or more pipes leading up through the bottom of the vat to the
underside of the strainer plates.
In order that my Invention may be properly understood and readily carried into
effect, I have hereunto appended five sheets of drawings on the several Figures of
which corresponding parts are marked with the same letters of reference.
.
"
Figure 1, is a longitudinal section partly in elevation of a strainer commonly known
as Watson's strainer" and as made by Messrs. Henry Watson & Sons, High Bridge
Works, Newcastle-upon-Tyne.
Figure 2, is a plan of the same, and Figure 3, a transverse section partly in
elevation. As the construction and mode of operation of the strainers shewn at
Figures 1, 2, and 3, is well-known to persons practically conversant with the straining
of paper pulp, there is no occasion to here further describe the said drawings than in
so far as relates to the methods or means for regulating and admitting air into the
said strainers according to my Invention. In the said Figures 1, 2, and 3, the
strainer plates are marked A, these being of the ordinary kind and formed with a
great number of narrow slits or slots or cuts B, as shewn at a portion of one end of
Figure 2. In one of the strainer plates A, (Figure 1) the air regulator C, is shewn
applied by being screwed thereinto. This regulator which is the form I prefer to
employ is shewn in enlarged detailed views at Figures 4 and 5, of which Figure 4, is
an elevation and Figure 5, a vertical section. The air regulator as shown at these
Figures consists of a hollow vertical stem D, screwed into the knotter or strainer
plate and in the upper part of which there is a valve seat E, for the purpose of
enabling the valve F, to be closed down upon or raised therefrom. Above the valve.

page_text: seat E, there is a hollow cup G, upon which the cover H, is screwed as shewn.
The spindle I, of the valve F, is formed with a screw as shown at Figure 5, and
this passes through a corresponding nut in the cover H, so that according to the
direction in which the screw I, is turned in the aforesaid nut, so the extent of
air space or opening between the valve F, and its seat E, is regulated. The
cover H, is also formed with perforations J, to allow air to be drawn in through
the valve opening by the sucking action of the strainer. The stem of the valve
spindle I, is provided with a hand wheel K, for turning it, and as a convenient
method of retaining the valve in its adjustable position a spring L, is used which
presses sufficiently against the rim of the wheel K, to prevent it from turning by
accident.
Besides attaching or applying the air regulating apparatus to the strainer plate it
may also be applid to a branch M, leading from the side of the strainer as shewn
at Figures 2 and 3, or such air regulators or equivalent regulators may be applied
both to the strainer plates and to one or more branches M, as shewn in plan
Figure 2.
At Figure 6, there is shewn in transverse section partly in elevation a strainer
of the kind known as Wrigly and Robertson's and which is fully described in the
specification of the said Wrigly and Robertson No. 5201 A.D. 1882. The strainer
plates in this case are also marked A, and into them the air regulator is fixed
in a manner similar to what is herein described with reference to Figures 1, 2
and 3.
On Figure 7, of the annexed drawings, I have shewn in vertical section of a
strainer of paper pulp commonly known as "Goodall's strainers," which strainer is
fully described and shewn in the Complete Specification and drawings of the said
Goodall and Webster No. 5528 A.D. 1887. In this arrangement of strainer two
air regulators C, are shewn applied, one at either side and at the upper part of
the vat containing the pulp to be strained.
At Figure 8, I have shewn a vertical section partly in elevation of a strainer for
paper pulp generally known as Amos and Clark's strainer and fully described in the
specification of Patent No. 12836 A.D. 1849. In this Figure 1 have shewn the air
regulator as applied both to the strainer plate A, as well as to a branch M, leading
from the side of the vat wherein the strainers are placed or contained.
It is to be understood that the foregoing represents some instances only of the kind
of paper pulp strainers to which my Invention is applicable and I wish it understood
that my Invention is applicable to pulp strainers generally. I also desire it to be
understood that I do not limit myself to any particular mode or construction of
regulator or equivalent apparatus by which the admission of air to paper pulp
strainers is effected.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
Providing one or more openings in pulp strainers to allow of the inflow thereinto
during the straining operations of any regulated amount of air so that the degree of
vacuum in the strainer is thereby diminished or made less than has been the practice
to use hitherto in the operation of straining pulp, substantially as hereinbefore
described and shewn upon the annexed sheets of drawings.
Dated this 8th day of January 1889.