es
from one chest to the next.

The pulp material with which the apparatus herein illustrated is
intended to be used is retained in suspension in the bleaching liquid
and flows readily through ducts or passages provided for it in the
apparatus in which the pulp to be bleached and the bleaching liquid
are introduced together at the bottom of each chest and flow upward
therethrough, while at the top of each chest there are two conveyors,
one for carrying the pulp from one chest to the next in order, while
the other carries the bleaching liquid from one tank to the next in
the reverse order, the said conveyors also acting to partially
separate the pulp from the liquid in which it has been suspended
during its upward passage through the chest.

Suitable agitators may be employed for thoroughly mixing the materials
in the chest and in the apparatus shown the bleaching agent and
material to be bleached pass through each chest in the same
direction--namely from the bottom to the top--although they are
carried from one chest to the next in the reverse order, the material
to be bleached being primarily introduced into the chest at one end of
the series, while the bleaching agent or solution is introduced
primarily into the chest at the other end of the series.

Fig. 1 is a plan view of an apparatus for bleaching in accordance with
this invention, comprising a series of four chests, and Fig. 2 is a
vertical longitudinal section of a modified arrangement of two chests
in line with one another, and with the conveyor for the material to be
bleached and the passage through which said material passes from the
top of one chest into the bottom of the next chest in the plane of
section.

[Illustration: Fig. 1]

The chests, _a_ _a2_ _a3_ _a4_, may be of any desired shape
and dimensions and any desired number may be used. Each of said chests
is provided with an inlet passage, _b_, opening into the same near its
bottom, and through this passage the materials are introduced. The
unbleached material, which may be paper pulp or material which is
readily held in suspension in a liquid and is capable of flowing or
being conveyed from one point to another in a semi-fluid condition, is
introduced through the inlet passage, _b_, to the first chest, _a_, of
the series, said pulp preferably having had as much as possible of the
liquid in which it was previously suspended removed without, however,
drying it, and, together with the said pulp, th