STRAINERS

157

The vibrating motion in this strainer is given to the whole vat, the drum re-
volving without shake, and no vibrating diaphragm being necessary. The
body of the vat rests on semicircular brackets which are attached at one end
to a spring, like the wire-frame spring support of a Fourdrinier wet end; the
other end of the bracket is pivoted to the shake arm, which is actuated by a
rod connecting to an eccentric shaft. The moving vat is connected to the
fixed parts by a rubber connection.

The stuff runs into the strainer from above and flows against the revolving
drum, passing through the slits to the inside and thence out at the ends to the
breast box. There is no violent action about the vibrating movement as in
the case of the 'Leith Walk' and Banning and Seybold flappers, the shake
given to the vat being easy and effective. It is claimed that only 25 per cent
of power is required to drive this
strainer compared with the diaphragm
or vibrating drum type.

The plates are interchangeable. The
strainer drum is closed at one end
and discharges stuff at the other, and
double packing strips are used to make
the joint between the drum and vat,
to prevent the mixing of screened and
unscreened stock. There is a spray pipe
at the top, and the water and loosened
stuff are caught in a winged trough.

The Box Strainer is a very old, but
extremely useful, type, which is capable
of dealing with almost any class of
fibres. A metal tank is set very firmly
on a good solid base. Inside this is a brass rectangular framework, on which are
bolted the strainer plates. These may be of any suitable 'cut'. They are
arranged in rows of four, sixteen in all, and form an oblong box. This
box revolves inside the tpnk, being connected at the back side through
packing glands, with a worm and screw gearing. The front side is open
through glands, and connected to a receiving box outside the main tank.
A series of rubber diaphragms or 'bellows' is arranged inside the plate
holder, and vibrated by a small crank and shaft which passes through the
centre of the revolving gear. The first disc or bellows makes the back
end of the plate box air- and water-tight. The strainer being set in motion,
the stuff is run into the outer tank. The vibration of the diaphragms
soon fills the inner box, and the level of the stuff in the receiving box

IBM M*h™ Co. a»d
49.— LATEST TYPE BOD SCREEN