Improvements in Stuff Chests for Paper Making Machines.
Year: 1887

page_text: Date of Application, 13th Sept., 1887.
Specification Accepted, 14th Oct., 1887
Improvements in Stuff Chests for Paper Making Machines.
I, RICHARD SMITH, of Sherbrooke, in the County of Sherbrooke, Province of
Quebec, Dominion of Canada, Gentleman do hereby declare the nature of my
invention for "1MPROVEMENTS IN STUFF-CHESTS FOR PAPER-MAKING MACHINES," 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 stuff-chests, so called, for paper-making machines, and
consists in the peculiar apparatus connected therewith, by which a more thorough
and complete mixing or stirring of the contents is effected.
These stuff-chests, ordinarily are large cylindrical vats or receptacles in which the
finely comminuted material, termed "stuff" or pulp is stored preparatory to its
delivery upon the paper-making machine, in the process of forming an endless paper
web. Hitherto said stuff-chests have been provided with an ordinary barred stirrer,
which fails in its purpose since the rotary movement produced thereby tends to
separate the heavy from the lighter particles composing the mass.
The object of my invention is to obviate such rotary movement, as tends to
separate the particles by centrifugal force, but yet to maintain a constant and
thorough mixing of the stuff, so long as any of it is retained in the chest. This I
effect by discharging the pulp, or contents of the chest from the latter centrally or
thereabouts then raise said stuff mechanically and finally deliver it into the chest at
the top and near the circumference thereof; thus a continuous flow of pulp is
maintained and no separation of the particles composing it can occur.
The drawings represent in Fig. 1. a plan and Fig. 2 a vertical sectional elevation
of a stuff-chest embodying my invention on line cx in Fig. 1. Fig. 3 represents a
modification.
In such drawings A represents a stuff chest, preferably circular in form, which
is connected with the beating engines from which it receives the pulp to be stored
therein; furthermore a pump, not shown, also connects with it and delivers said
stuff upon the paper-making machine, as it is required. This chest is closed at top
and bottom.
To the walls of the stuff-chest are secured and vertically arranged a series of bent
pipes, or conveyors B B, the lower ends of which are inserted in the bottom C of

page_text: the chest, at or near the center. The upper extremities of said conveyors enter the
top D, preferably at or near the circumference of the chest.
Furthermore each of these conveyors are hollow and contain in the present
instance, a vertically disposed shaft, about and to which is secured a spiral blade ;
the transverse diameter of this latter is equal to the bore of the conveyor and snugly
fits it. Motion of these several shafts a a is obtained by means of a shaft E, which is
stepped on the top D of the stuff-chest and carries a spur-wheel F intermeshing with
pinions c c surmounting the ends of the shafts a a, which, if desired, may be provided
with stuffing boxes at the point, where they emerge from the conveyors to more
effectually prevent escape of pulp, when the latter is in circulation.
The operation of the apparatus is easily perceived, after pulp has been supplied
into the stuff-chest and rotation of the shaft E and spur-wheel commenced by means
of some prime motor. Movement of the latter produces rapid rotation of the shaft a
and spiral blade b, but since the latter is contiguous to the interior of the conveyors
the pulp is forced therethrough, being drawn from the bottom and quickly and rapidly
lifted and discharged into the top of the chest.
Thus a rapid circulation is maintained, continuous even stirring is produced, while
the movement is such that the heavy and light particles do not tend to separate, but
are kept thoroughly commingled and in the best condition to produce a uniform sheet
of paper, dependent upon the proportions and kinds of stock employed.
In Fig. 2 I have employed a filling d d or false bottom for the stuff-chest in order
to cause the pulp to gravitate towards and flow into the conveyors. Thus the chest
can be readily and thoroughly cleansed, while the waste material, such as grit, or
other foreign particles may be removed through the valves e e.
By this method of stirring the contents of a stuff-chest the entire interior of said
chest is free from obstruction, no chance is offered for the formation of strings, so
called, and the mixing of the pulp is more effectual.
I do not desire to be limited to the precise form of lifting apparatus located within
the conveyor, but any device, which will effect a rapid withdrawal of the pulp from
below, and which will discharge the same into the top of the stuff-chest for the purpose
of mixing the contents, I consider within the scope of my invention. Nor do I
desire to be confined to the precise location, or arrangement of the conveyors, as they
may be placed within the chest, if so desired, as shown in Figure 3 of the drawings.
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 :-
1st. In stirring apparatus the combination with a storage receptacle of a series of
conveyors which connect with the top and bottom of the same and spiral lifting devices
ascending in said conveyors, whereby the contents are continuously withdrawn from
the bottom and discharged into the top, substantially as and for the purpose
sct forth.
2nd. The combination with a stuff-chest A, of one or more conveyors attached
thereto, and provided with a continuous rotary shaft a and spiral blade b, operating
substantially as specified.
3rd. The stuff-chest A provided with a bottom interiorly cone-shaped, and a series
of conveyors B B, which enter at the top and bottom thereof, in combination with the
shaft E, spur-wheel F and pinion cc, which actuate the shafts and blades within said
conveyors substantially as described.