Document ID: EPA-HQ-OAR-2002-0039-0041
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2003-08-28T04:00Z

1
Date:
May
29,
2003
Subject:
Meeting
Summary
­
EPA
and
representatives
from
U.
S.
Steel
From:
Chris
Sarsony,
Alpha­
Gamma
Technologies,
Inc
To:
Docket
OAR­
2002
 
0039
I.
Purpose
The
primary
purpose
of
the
meeting
was
to
discuss
U.
S.
Steel's
technical
comments
regarding
operating
limits
for
venturi­
rod
deck
scrubbers
used
to
control
emissions
from
the
indurating
furnace.

II.
Date
May
29,
2003
III.
Attendees
U.
S.
Environmental
Protection
Agency
Conrad
Chin,
OAQPS/
ESD/
MG
Peter
Westlin,
OAQPS/
EMD
U.
S.
Steel
Representatives
Bill
Kubiak,
U.
S.
Steel
Larry
Salmela,
U.
S.
Steel
Tom
Moe,
U.
S.
Steel
Alpha­
Gamma
Technologies
Chris
Sarsony
IV.
Discussion
A.
Operating
Limits
for
Venturi
Rod­
Deck
Scrubbers
°
Issue:
U.
S.
Steel
representatives
stated
that
for
the
venturi
rod­
deck
scrubbers,
they
can
measure
the
pressure
drop,
but
they
cannot
directly
control
it
(
see
OAR­
2002­
0039
IV­
E­
8
2
background
discussion
below).
Therefore,
they
believed
that
they
could
not
establish
a
"
not
to
go
below"
pressure
drop
value
for
these
scrubbers.

°
U.
S.
Steel's
Suggested
Operating
Requirements:
They
requested
that
EPA
require
the
following
for
venturi
rod­
deck
scrubbers
controlling
emissions
from
indurating
furnaces:

S
Must
establish
a
scrubber
water
flow
limit
during
the
initial
compliance
test
and
maintain
a
rate
at
or
above
that
limit.
Any
drop
below
the
established
limit
would
be
an
exceedance.

S
Must
establish
a
scrubber
pressure
drop
level
during
the
initial
compliance
test.
Any
drop
below
the
established
level
and
they
will
do
investigation
within
1
hour
to
see
if
process
and
scrubber
are
functioning
normally.
This
would
not
be
considered
an
exceedance
or
a
violation.

°
Alternative
Operating
Requirements
Explored:

S
Option
1:
Must
establish
a
scrubber
water
flow
limit
during
the
initial
compliance
test
and
maintain
a
rate
at
or
above
that
limit.
Any
drop
below
the
established
limit
would
be
an
exceedance.

Must
establish
a
scrubber
pressure
drop
limit
during
the
initial
compliance
test.
Compliance
with
this
limit
would
be
determined
on
a
7­
day
rollingaverage
basis.
After
the
first
time
and
second
time
they
are
below
the
limit
they
would
have
to
perform
corrective
action.
After
the
third
time
they
are
below
the
limit
in
any
semiannual
period
it
would
be
considered
to
be
an
exceedance.

S
Option
2:
Determine
the
critical
flow
below
which
the
scrubber
no
longer
functions
as
a
venturi.
We
called
Hal
Taylor
of
STS
consulting
(
847­
279­
2541).
Mr.
Taylor
indicated
that
there
were
informal
studies
conducted
in
the
early
`
70'
s
that
showed
that,
for
a
multiple
throat
venturi,
below
2"
of
pressure
drop
the
efficiency
dropped
sharply.
He
indicated
that
in
practice
it
is
hard
to
identify
this
point
and
it
was
not
determined
when
engineering
the
controls
for
U.
S.
Steel.

°
Background
Discussion:
They
cannot
directly
control
the
pressure
drop
across
the
venturi
rod­
deck
scrubbers
because:

S
the
scrubbers
are
of
a
fixed
throat
design,

S
the
fan
operates
at
a
fixed
speed
and
fixed
diameter,
and
S
the
damper
prior
to
the
scrubber
is
used
to
control
the
overall
flow
of
air
3
through
the
system,
therefore,
it
cannot
be
used
to
control
the
pressure
drop
to
the
scrubber
without
affecting
the
entire
process.

°
To
illustrate
their
point
they
presented
a
flow
diagram
of
one
of
their
indurating
furnace
lines
at
Minntac.
They
showed
how
the
damper
leading
to
the
scrubber
controls
the
flow
of
air
through
the
entire
indurating
system.
This
damper
is
opened
more
or
closed
more,
as
necessary,
to
modulate
the
air
flow
as
changes
occur
in
the
process.
Examples
of
process
changes
included
production
rate
changes,
changes
in
the
thickness
of
the
bed
of
pellets,
or
malfunction
conditions,
such
as
the
release
of
fines
onto
the
traveling
grate.
As
production
rate
increases
the
damper
is
opened
more,
and
therefore,
the
pressure
drop
across
the
scrubber
increases.

°
They
characterized
the
change
in
pressure
in
the
system
with
the
following
equation:

 
P
Fan
=
 
P
Scrubber
+
 
P
Bed
+
 
P
Damper
The
fan
is
a
fixed
speed
and
fixed
diameter
fan,
therefore,
they
cannot
control
pressure
drop
via
the
fan.
The
scrubber
is
a
fixed
throat
scrubber,
therefore,
they
cannot
control
pressure
drip
via
the
scrubber.
The
pressure
drop
through
the
bed
of
pellets
is
variable
and
depends
on
the
process
changes
mentioned
above.
The
damper
controls
the
pressure
drop
to
compensate
for
changes
in
the
pressure
drop
through
the
bed
of
pellets.
For
process
lines
4
and
5
the
damper
is
typically
100%
open,
for
process
lines
6
and
7
the
damper
is
typically
85%
open.

°
In
a
previous
meeting,
representatives
from
U.
S.
Steel
indicated
that
if
the
damper
was
open
100%
it
was
a
malfunction.
EPA
asked
for
U.
S.
Steel
representatives
to
clarify
the
apparent
contradiction
of
this
statement
and
the
fact
that
some
of
the
furnaces
operate
normally
with
the
damper
open
100%.
Representatives
from
U.
S.
Steel
indicated
that
a
100%
open
damper
could
indicate
a
malfunction,
but
not
always.
It
would
be
a
malfunction
if
the
damper
were
open
100%
but
the
flow
of
air
through
the
scrubber
is
still
low.
This
can
occur
when
the
bed
of
pellets
on
the
travel
grate
gets
clogged
and
does
not
allow
the
air
to
flow
through
as
it
should.

B.
Gouping
of
Similar
Emission
Units
°
U.
S.
Steel
provided
comments
and
changes
on
the
way
we
grouped
their
units.
Overall,
they
stated
that
their
groupings
are
very
similar
to
our
groupings.
4
C.
Action
Items
°
U.
S.
Steel
to
provide
pressure
drop
data
for
the
rod­
deck
scrubbers
on
indurating
furnaces,
for
all
production
rates,
excluding
malfunctions.
The
data
will
be
provided
as
daily
average
pressure
drop
and
7­
day
average
pressure
drop.