Ponderay Newsprint
 The 4-foot diameter, 25-foot tall HTR vessel at Ponderay Newsprint (Usk, WA) uses
vent gases from disc filters and cloudy whitewater to heat whitewater from 130°F
to 170°F. In this system, whitewater is directly contacted with the vent gases to
maximize energy transfer. The system recaptures over 3,400 LB water/HR (at 175°F.)
and saves the company over 7.7 million BTU/HR. No photo is available for this system
because its location is too cramped to be able to step back and get a perspective
on it; therefore we’ve attached part of a CADD (Computer-Aided Design Drawing) file
for illustrative purposes. Direct Contact LLC (DCLLC) is experienced
in fitting large processes into relatively tight spaces.
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Nippon Paper
 DCLLC will install the fourth major
direct contact heat recovery system
in Nippon’s Port Angeles facility in
the spring of 2012. This newest
system is a hybrid with indirect
heat exchange preceding a DCLLC
Hydrothermal Recovery (HTR)
Vessel. The heat source for this
system will come from a new hog-
fuel fired boiler producing steam
both for energy production and the
mill’s process needs. This system
will replace part of the No.8 Boiler
heat recovery system shown in the
picture to the right. The system
heats turbine exhaust condensate
using a flue-gas-to-water indirect
heat exchanger and a water-to-
water indirect heater exchanger
with contact water from the HTR
vessel. Boiler make-up water is
also heated with a heat exchanger
using contact water. In addition,
a second contact water loop is
circulated through two remote
heat exchangers, generating hot
process water and heating central
filtrate water to be used in the pulp
mill. This complex new system
will be integral to the efficient use
of thermal energy throughout the
facility. The system is designed to
recover over 57 million BTUs/HR.
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