Evaluation of an on farm press


Blake, J.A.

Publication, American Society of Agricultural Engineers (4-82): 247-251

1982


A farm scale press was evaluated in terms of throughput, oil removal, quality of oil, and effect of seed conditions on throughput and oil quality of rapeseed. The press consists of a driven constant pitch worm inside a cage of 12 triangular shaped plates arranged perpendicularly to the axis of the worm. Preliminary indications are that the press is very reliable. Oil output of 9-10 litres/hr has been attained for seed with an m.c. of 6-7%. Throughput drops off from 25 to 15 kg/hr and oil removal worsens considerably when seed with an m.c. of 9-10% is expelled.

EVALUATION
OF
AN
ON
FARM
PRESS
J.
A.
Blake
POS
PILOT PLANT
CORPORATION
U
of
S
Campus
Saskatoon,
Saskatchewan
ABSTRACT
POS
has
evaluated
the
Simon-Rosedowns
mini-40
farm
scale
press
in
terms
of
throughput,
oil
removal,
quality
of
oil,
and
effect
of
seed
conditions
on
throughput
and
oil
quality.
Preliminary
indications
are
that
the
press
is
very
reliable
and
rugged.
Oil
output
of
9-10
litres/hour
has
been
attained
for
6-7%
moisture
seed.
Throughput
drops
off
from
25
to
15
kg/hr
and
oil
removal
worsens
considerably
when
9-10%
moisture
seed
is
expelled.
EVALUATION
OF
AN
ON
FARM
PRESS
POS
Pilot
Plant
Corporation,
Saskatchewan
Research
Council
and
the
Department
of
Agricultural
Engineering,
University
of
Saskatchewan
have
been
engaged
in
a
joint
project
to
evaluate
the
use
of
Canola
oil
as
a
diesel
fuel
extender/
replacer
in
diesel
engines.
One
aspect
of
this
project
is
the
evaluation
at
POS
of
the
Simon-Rosedowns
Mini-40
screw
press
as
a
farm
scale
screw-press
to
expell
the
oil
from
Canola
seed.
(Canola
is
a
low
erucic
acid,
low
glucosinolate
type
of
rapeseed
which
has
been
developed
in
Canada
for
its
nutritional
qualities).
The
Simon-Rosedowns
press,
(Figure
1)
consists
of
a
driven
constant
pitch
worm
inside
a
cage
of
twelve
triangular
shaped
plates
arranged
perpendicularly
to
the
axis
of
the
worm.
At
the
exit
end
of
the
cage,
the
worm
has
a
smooth
tapered
section.
The
entire
worm
can
be
moved
axially
by
a
hand
operated
drive
in
order
to
narrow
down
the
exit
opening
and
thus
adjust
the
exit
cake
thickness
and
the
back
pressure
on
the
material
between
the
worm
and
the
cage.
The
cage
section
mounts
between
two
heavy
metal
plates
and
is
held
in
place
by
3
bolts
which
pass
through
the
apices
of
each
triangular
section
and
through
each
heavy
plate.
The
distance
between
each
cage
is
adjusted
by
placing
metal
washers
of
0.13,
0.25,
0.51,
or
0.76mm
on
the
bolts
between
the
sections.
In
addition,
part
of
each
side
of
each
plate
is
hollowed
out
so
that
oil
expelled
outward
between
the
plates
does
not
have
to
travel
the
entire
thickness
of
the
plates
but
only
a
narrow
region
(land)
surrounding
the
worm.
The
original
cross-section
of
the
centre
hole
in
each
plate
was
circular.
Feed
is
by
gravity
into
a
hopper
arranged
just
in
front
of
the
cage.
The
initial
arrangement
had
0.76mm
spacers
on
the
first
6
plates
at
the
feed
end
and
0.25mm
spacers
at
the
cake
end.
This
configuration
and
a
number
of
variations
of
spacing
were
of
little
use
for
the
expelling
of
Canola.
Feed
rate
was
less
than
15
kg/hr
and
the
machine
was
prone
to
blockage,
excessive
fine
material
in
the
oil
and
puddling
of
oil
inside
the
machine.
This
latter
effect
over
lubricated
the
cage
and
throughput
dropped
drastically
or
ceased
altogether.
247
-1---Choke
Setting
'Choke
Lock
Driv
Triangular
Plate
Inlet
Cage
'
403
044AOXP
Worm
Figure
1.
Schematic
Diagram
of
Mini-Press
Simon-Rosedowns
provided
a
new
cage.
This
cage
has
narrower
lands
and
the
central
hole
has
3
roughened
cusps
or
lobes
arranged
equilaterally
around
the
central
hole.
Simon-Rosedowns
also
recommended
reducing
the
taper
of
the
worm
These
changes
improved
the
operation
of
the
press
but
major
problems
were
not
eliminated until
we
switched
from
controlled
flow
to
fully
flooded
input.
The
machine
works
best
with
a
full
hopper
and
no
attempt
to
control
feedrate.
Flooded
input
allowed
us
to
operate
continuously,
but
there
were
still
problems
with
excessive
fines
and
poor
oil
removal.
After
trying
a
variety
of
cage
spacings,
we
carried
out
most
of
our
work
with
the
first
3
spacings
at
0.76mm,
the
next
2
at
0.51mm
and
the
last
6
at
0.25mm.
This
configuration
has
given
oil
with
moderate
fines
level.
Recently
we
have
shown
that
changing
the
last
3
spacings
to
0.13mm
reduces
the
fines
further.
We
have
no
exact
value
for
fines
as
yet
as
we
are
developing
a
filtering
system
which
will
allow
a
more
exact
quantitation
of
fines.
Oil
removal
depends
on
choke
setting,
seed
moisture,
and
characteristics
of
the
seed.
Choke
setting
is
taken
as
a
number
engraved
on
a
choke
lock
and
varies
from
0
fully
open,
to
30
fully
closed.
The
practical
range
is
from
20
to
26
or
to
cake
thicknesses
of
0.9
to
0.45mm
(Figure
2).
The
good
correlation
exemplified
between
the
cake
thickness
and
choke
setting
is
not
carried
over
into
the
relationship
of
cake
thickness
to
residual
oil
con-
tent
or
to
feed
rate
when
data
for
all
seed
moistures
are
included.
A
plot
of
percentage
oil
remaining
vs.
choke
setting
is
approximately
linear
only
if
dry
seed
(less
than
7%
moisture)
is
pressed.
248
Ca
ke
T
h
ic
kness
1
1.
0.8
0.6
1.6
1.4
1.
S
0.
0.2
14
16
18
20
22
24
26
Choke
Setting
Figure
2.
The
Relationship
of
Cake
Thickness
to
Choke
Setting
A
moisture
content
in
excess
of
9%
adversely
affects
operation
of
the
pr4ss.
Throughput
is
reduced
to
about
60%
of
normal
and
it
is
difficult
to
obtain
a
residual
oil
content
less
than
25%.
The
cake
also
breaks
into
small
soft
pieces
instead
of
the
large
leathery
pieces
obtainable
at
lower
moistures.
We
have
not
ascertained
as
yet
the
upper
limit
of
moisture
for
practical
operation
of
the
press
but
it
appears
to
be
in
the
7-8%
moisture
range.
Feed
rate
is
usually
25
kg/hr
or
less
for
residual
oil
less
than
20%
but
in
one
run
we
attained
28.4
kg/hr
and
17.3%
residual
oil.
This
was
achieved
with
approximately
7%
moisture
seed.
Our
usual
throughput
is
about
60-70%
of
rated
throughput.
Oil
quality
is
excellent.
Free
fatty
acid
(ffa)
is
0.13
to
0.38%
on
one
lot
of
seed
and
0.5
on
another.
The
higher
value
on
the
first
lot
of
seed
occurred
when
we
pressed
10%
moisture
seed.
The
free
fatty
acid
values
probably
reflect
the
free
fatty
acid
valbes
in
the
seed.
Expulsion
of
good
seed
by
the
normal
cooking
prepressing
rpute
would
give
0.3
-
0.5%
ffa.
Peroxide
values
are
excellent
at
0.3
-
0.5
meq/kg. These
values
show
that
the
minipress
oil
is
of
excellent
edible
quality
and
that
it
should
not
oxidize
readily.
Phosphorous
content
in
the
oil
is
in
the
range
8-50
ppm.
This
is
much
lower
than
the
200-300
ppm
normal
for
oil
produced
by
conventional
expelling.
This
level
of
gums
should
give
no
problems
in
diesel
fuel
use.
Sulphur
levels
at
6-7
ppm
are
high
for
edible
use
but
negligible
for
diesel
conditions.
249
36
.
34.
32.
8
1-10-82
X
30.
I
1-10-82
28.
r
1-10-82
26.
15-12-82
••• 4
24.
22.
20.
1-12-82
18.
2-16-82
2-12-82
16.
L
1-16-82
144
12
14
16
18
20
22
24
26
Choke
Setting
Figure
3.
Percentage
oil
remaining
in
the
seed
vs.
choke
setting
for
Regent
seed
of
less
than
71
moisture.
The
numbers
on
the
graph
are
run
numbers.
We
have
also
expelled
two
lots
of
cold
seed.
Unfortunately,
the
press
is
mounted
in
a
heated
room
and
seed
at
-12
°
C
warmed
to
as
much
as
12
°
C
while
sitting
in
the
input
hopper.
Even
under
these
conditions
we
noticed
a
discharge
of
dry
material
from
the
front
cage
openings
and
a
slightly
higher
residual
oil
content
in
the
cake.
Cake
temperatures
vary
from
as
low
as
70
°
C
to
as
high
as
120
°
C.
Oil
temperature
is
only
50-60
°
C
as
most
of
the
oil
is
expelled
in
the
middle
part
of
the
press
before
the
frictionally
generated
temperature
rises
very
much.
The
press
has
been
very
reliable
in
operation.
Approximately
5
tonnes
of
seed
have
been
pressed
including
1
tonne
of
dehulled
Canola
pressed
at
very
high
pressure
and
low
throughput.
In
this
time
only
one
thrust
bearing
has
been
replaced.
Start-up
is
almost
immediate.
We
have
obtained
good
oil
removal
from
as
little
as
4
kg
of
seed.
There
is
no
point
in
recycling
cake,
however,
as
oil
removal
from
recycled
cake
is
negligible.
Rate
of
oil
production
varies
with
conditions
of
operation
but
averaged
9
to
10
litres/hour
(2.2
Imperial
gallons/hour)
for
dry
seed
and
residual
oil
in
the
cake
of
16-20%.
Our
major
goal
in
this
work
has
been
to
raise
the
capacity
of
the
press
while
maintaining
good
oil
removal.
250
We
have
not
been
able
to
reach
the
rated
capacity
with
good
oil
removal.
While
capacity
enhancement
has
been
our
main
goal,
we
have
also
tried
to
determine
relationships
among
choke
settings
and
throughput,
percentage
oil
in
the
cake,
effect
of
moisture
in
the
seed.
This
work
is
still
ongoing
and
we
hope
for
more
definite
correlations
in
the
near
future.
251