2017 International Forest Industries Magazines October November 2017 | Page 25

SAWLINES – SHIFTING & SORTING: USNR
to accommodate cut-n-two boards
in a smaller sorting footprint than
would traditionally be required for
so many sorts:
• Split diverter shafts: The first
sorting solution involves split
diverter shafts in the sorter top.
Each split diverter shaft has its
own dedicated cylinder and valve
at the nearest end of the bin.
One portion of the split shaft
actuates to pick out one of the
cut-n-two board pieces, or both
portions of the shafts actuate
together for a full-length board.
The diverter shafts can be split in
differing locations for a variety of
product mixes. With this design,
the sorter is divided into zones
for various products, and each
zone has its own configuration
for bin walls.
As an example, for a 20 ft
system, Zone 1 could sort 8 ft or
10 ft clear line boards, and in the
same zone could sort 8 ft, 10 ft
or 12 ft lumber line boards. As
well, Zone 1 bins could sort full
length lumber line products. Zone
1 bin walls would be configured
to accommodate these board
products to clear line and to lumber
line.
In the same example, Zone 2
could sort 8 ft, 10 ft or 12 ft clear
line boards, and 8 ft lumber line
boards. Zone 2 bins could also
sort full length products. Zone 2
bin walls would be configured to
accommodate these clear line and
lumber line board products.
Zone 3 bins would be standard
bins and accommodate full length
board products, with the option
to also accept any cut-n-two
lumber line boards. Zone 3 would
be fitted with single bin diverter
shafts and cylinders for each bin.
Bin discharge chains would be
configured to handle near side and
clear line side end boards.
• T  andem bins: With a tandem
bin sorting configuration, two
short length sorters are located
side-by-side with independent
bin floors. They are contained
under a single sorter top, with
dedicated diverters, shafts,
and floors for lumber line and
clear line, as well as dedicated
discharge chains with an
interchange rollcase. A standard
full width sorter is located
behind either of the side-by-side
sorters.
With this example, for a 20
ft system, the clear line tandem
bins accept 8 ft, 10 ft or 12 ft clear
LUMBER PROCESSING
line products. The lumber line
tandem bins accept 8 ft, 10 ft or
12 ft lumber line products. Clear
line bins reverse discharge to an
interchange rollcase, then travel on
to the stacker in the same direction
as the lumber line bins and full-
length bins.
The full-length standard bins
accept any full-length lumber line
boards, with the option to accept
any cut-n-two lumber line boards.
It shares the same sorter top as the
tandem bins.
Considerations
The benefits of these options can
be huge for mills that produce
a high percentage of cut-n-two
products. As the percentage goes
up, the return on investment is
increased.
“The configuration that
may appeal to a particular mill
will depend on factors such as
space availability, cost of capital
equipment, the number of
products (sorts) and the level of
product flexibility a mill requires
to gain the highest return,” the
manufacturer said. “Be assured,
these configurations are all
installed and operating in multiple
locations, and we can arrange for
lumber processors to view them
first hand.”
USNR’s WinTally sorter
management system
accommodates any of these
options, and MyMill mobile sorter
control can make it easy to manage
the wide variety of products
produced, from anywhere in the
mill.
Tandem bins: With a tandem
bin sorting configuration,
two short length sorters are
located side-by-side with
independent bin floors. A
standard full width sorter is
located behind either of the
other side-by-side sorters
International Forest Industries | OCTOBER / NOVEMBER 2017 23