Complete White Water Treatment
in a Tissue Mill
A. G. Leonard, Jr., President, Stonebridge Paper Company
Wilmington, Illinois
and
R. J. Keating, Graver Water Conditioning Company
New York, New York
A properly designed white water treatment system can produce
many benefits for the user, among them maximum recovery of valuable
fiber and filler, recovery and reuse of treated water, low cost operation
and maintenance, and simplicity of equipment. These benefits can produce an appreciable return for the user which can sometimes pay for the
system in a very short time and thereafter contribute to an economical
operation. On the other hand, a poorly designed system can result in
inadequate treatment, stream pollution, and a waste of materials. In
the end, there is no return on the investment and the treatment system
can cost the plant money on a continuing basis.
The Stonebridge Paper Company of Wilmington, Illinois, manufactures an assortment of specialized quality paper products including dentist bibs, paper napkins, absorbent tissues, and high grade cellulose
wadding. These products are made from wood pulp purchased from a
western mill. Processing water is supplied by drip wells in the area.
The plant operates on a 24-hour-day, 7-day-week basis, and has a rated
output of 40,000 lbs of paper per day. A pressurized flotation save-all
unit had been used to treat white water.
The old method
The old save-all unit at Stonebridge reduced suspended solids in
the white water from 500-1,000 ppm to 50-100 ppm. The unit was very
sensitive to upset and, in addition, it could not clarify the water sufficiently. This resulted in continuous plugging of the showers and felts.
Perhaps most important, the unit could not thicken the pulp sufficiently
for efficient return to the beaters and eventually to the large paper machine. For this reason much of the white water, together with floor
drains, overflows, and intermittent losses from changeovers and wash-
ups had to be discharged to the stream adjacent to the plant. The
stream, Forked Creek, carried the effluent to a river in the area.  Even
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