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United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/6GO/S2-85/071 Aug. 1985
&EPA Project Summary
Engineering Evaluation to
Examine Air Pollution Control
Technology Used in Foreign
Practice of Steelmaking
David W. Coy, Benjamin H. Carpenter,
James J. Spivey, and Richard Jablin
A study was conducted to determine
if technology used to capture and con-
trol fugitive dust emissions in the for-
eign practice of Steelmaking is superior
to that in use domestically. Foreign
technology was compared to that in
use domestically. Where apparently su-
perior technology was identified, a fea-
sibility study was performed to show
the technology's domestic applicabil-
ity. ,
Roof-mounted electrostatic precipi-
tators (REPs) were identified as poten-
tially superior technology. Using engi-
neering data from an existing U.S. basic
oxygen furnace shop and engineering
design details for a Japanese supplied
REP, costs of retrofitting the technol-
ogy to an existing plant were estimated
along with energy consumption, build-
ing modifications necessary, utility and
wastewater treatment needs, and ex-
pected performance.
A visible emissions evaluation pro-
gram was conducted in a Japanese
Steelmaking plant to determine the ef-
fectiveness of REPs in capturing and
controlling fugitive emissions. REP
electrical performance data obtained
during this program and dust charac-
teristics data from three fugitive dust
sources in Steelmaking operations
were input to an electrostatic precipita-
tor (ESP) computer model, and esti-
mated performance was calculated.
Good agreement was obtained be-
tween the actual measured perfor-
mance of the REP and the computer
predicted performance for the source
where the evaluation program was per-
formed.
This Project Summary was devel-
oped by EPA's Air and Energy Engineer-
ing Research Laboratory, Research Tri-
angle Park, NC, to announce key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report or-
dering information at back).
Introduction
The purpose of this project was to
perform an engineering evaluation of
fugitive emission control technology in
use in Japan and Western Europe, and
(where judged to be superior to domes-
tic technology) to show the foreign tech-
nology's applicability to domestic steel-
making practice. In evaluating foreign
technology, emphasis was to be given
to technology applicable to basic oxy-
gen furnace (BOF) Steelmaking. Follow-
ing identification of apparently superior
technology, on-site test programs to
measure control effectiveness were
planned for two sites.
Both foreign and domestic technolo-
gies were evaluated on data gathered
by a literature search and plant visits.
Five plants were visited in Western Eu-
rope and 12 plants in Japan. Technol-
ogy and performance were compared
between three recently constructed U.S.
BOF shops and the foreign facilities.
Based on these comparisons, only one
foreign technology offers substantial
performance effectiveness improve-
ment with significantly reduced energy
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consumption: roof-mounted electro-
static precipitators (REPs). Two other
technologies were identified as offering
some improvement in capture and con-
trol effectiveness when applied to a spe-
cific furnace type or a furnace enclo-
sure: an automatic sampling lance
(which eliminates the need to turn down
a BOF vessel to get a metal sample);
and compressed air curtains (to prevent
leakage from viewing ports in a furnace
enclosure).
A feasibility study was performed to
determine the applicability of REPs to
existing domestic BOF fugitive dust
sources. Among the factors considered
in the feasibility study were changes
needed to existing plant facilities, esti-
mated cost to modify the old facilities
and add the new equipment, and the
expected performance of the REPs.
Due to the difficulties in securing per-
mission to test in foreign facilities,
on-site performance was evaluated in
only one plant. The desired site for eval-
uation was a BOF shop with REPs. Per-
mission to test in BOF shops could not
be obtained from the plants' owners. A
visible emissions performance evalua-
tion was finally arranged in an electric
arc furnace steelmaking shop with an
REP.
Data obtained during the perfor-
mance evaluation was used in conjunc-
tion with an ESP computer model to
predict performance of REPs on other
fugitive dust sources in iron and steel-
making.
Summary and Conclusions
The two categories of systems for
BOF secondary emissions capture and
control seen in the foreign plants were
based on: (1) local hooding only, and
(2) local hooding plus partial building
evacuation.
Plants with only local hooding pre-
dominated for the plants visited. In re-
spect to the performance or capture
capability of the local hooding applica-
tions, the best systems observed cap-
tured virtually all of the secondary emis-
sions. The method of estimating
capture efficiency was subjective, but
best performance for all secondary
emission sources was in the range of
90-100 percent capture.
While the partial building evacuation
systems for furnace emissions were not
in the majority, in several situations,
such installations may offer advantages
over the use of only local hooding. In
particular, the use of REPs with no fans
or minimal fan assistance, and there-
fore no significant energy costs, may be
a cost effective alternative to complete
reliance on local hooding connected to
fabric filters.
The particulate collection device in
most common use for secondary emis-
sion control systems is the fabric filter.
Scrubbers and ESPs were used in only a
few of the plants visited.
Based on performance observations
and design data, the Italsider Taranto
Works and Nippon Steel Yawata Works
were selected as the plants with the best
overall secondary emission control sys-
tems for top-blown furnaces in Western
Europe and Japan, respectively.
A comparison of visible emissions
evaluation data and engineering design
data for the Kaiser Steel Fontana BOF
shop (a new U.S. plant completed in
1978 with similar control systems) with
data obtained during visits to the
Italsider Taranto Works and the Nippon
Steel Yawata Works suggests that the
technology in use in these plants is
equivalent.
The only foreign bottom-blown facil-
ity visited was Kawasaki Steel's Chiba
Works. Comparison of hood capture ef-
fectiveness estimates for furnace sec-
ondary emissions between the Chiba
Works and Republic Steel's Q-BOP at
South Chicago indicates that the
Japanese plant capture is at least as
good or better. Given that furnace emis-
sion escaping capture at the Chiba
Works furnace enclosure are further
subject to capture in the REPs, the impli-
cation is that overall effectiveness is
better at the Chiba Works than at Re-
public Steel.
No REPs are in use in the U.S. A feasi-
bility study was conducted on the appli-
cability of the technology to a typical
U.S. BOF shop. For a typical facility
which contains two BOF furnaces of 273
tonne (300 ton) capacity each, the esti-
mated cost, delivered and erected on
site is $3,020,000 or 60 percent of the
estimated project cost. The remaining
costs are absorbed primarily by struc-
tural reinforcement and modification of
the existing BOF building. The total esti-
mated project cost is $5,010,000. Esti-
mated annual operating costs are
$654,000. (All costs are estimated in
third quarter 1982 dollars.)
The existing BOF building chosen for
study would require extensive bracing
and reinforcement to sustain the loads
imposed by the REPs, primarily against
wind loads at right angles to the build-
ing aisles. A computer analysis was per-
formed on the existing BOF building. At
crosswind speeds of 100 mph (161
km/hr), drift of the structure may be a
problem which requires further struc-
tural analysis.
The critical phase of furnace opera-
tion with respect to REP performance is
hot metal charging. Using emission fac-
tors and several assumptions, the inlet
concentration during hot metal charg-
ing is estimated as 0.96 g/acm (0.42
gr/acf), giving an estimated outlet con-
centration of 0.082 g/acm (0.036 gr/acf)
where only one REP receives the fumes.
The range of concentrations estimated
to produce 20 percent opacity at the REP
discharge is 0.112-0.222 g/acm
(0.049-0.097 gr/acf). Therefore, it ap-
pears that the REP installation can
achieve discharges of less than 20 per-
cent opacity during hot metal charging.
A number of assumptions were neces-
sary to make these performance esti-
mates. It is important to verify the valid-
ity of some of these assumptions prior
to proceeding with an installation.
A visible emissions performance
evaluation was made on an REP applied
to a Japanese electric arc furnace (EAF)
steelmaking shop. The visible emis-
sions performance data showed 95 per-
cent of the 6-minute average opacities
were 6 percent or less, with less than 1
percent of the averages exceeding 10
percent opacity. This performance is
relatively good, but not quite as good as
required for compliance with the pro-
posed NSPS for EAF building dis-
charges; i.e., no reading exceeding 6
percent opacity. Analysis and compari-
son of the Japanese furnace operating
practices to U.S. practice suggests that
the Tokyo Steel practice provides a
greater potential for fugitive emissions
and, therefore, represents a more diffi-
cult control situation than would be typ-
ical of a U.S. plant at present. Operator
training, revisions to the furnace offtake
duct design, and adequate operating
practice information at the time of REP
design are potential means for improv-
ing the REP performance.
Subsequent to the visible emissions
performance evaluation at the Jap-
anese EAF plant, a study was under-
taken to determine the applicability of
the EPA/Southern Research Institute
computer model of ESP to the REP. REP
electrical data and EAF dust characteris-
tics data were used as model inputs,
and REP efficiency and stack opacities
were computed. The computer model
predictions were in good agreement
with previously measured performance.
Performance was predicted for other
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steel plant sources using dust charac-
teristic data appropriate for those
sources.
Results show that the ESP computer
model can be useful in investigating
ESPs applied to industries other than
coal-fired boilers. The model study sug-
gests that an REP can be equally effec-
tive when applied to BOF fugitive emis-
sions and blast furnace casthouse
fugitive emissions. Additional tests of
the model for various sources in the
iron and steel industry are necessary to
provide the same level of confidence in
the model as exists in the utility indus-
try. Such tests should include measure-
ment of in-situ electrical resistivity and
simultaneous measurement of inlet and
outlet particulate size distribution and
mass loading.
D. Coy, B. Carpenter, andJ. Spiveyare with Research Triangle Institute, Research
Triangle Park, NC 27709; R. Jablin is with Jablin Associates, Durham, NC
27705.
Robert C. McCrillis is the EPA Project Officer (see below).
The complete report, entitled "Engineering Evaluation to Examine Air Pollution
Control Technology Used in Foreign Practice of Steelmaking," (Order No. PB
85-216 596/AS; Cost: $25.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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