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November 2018
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World Cement
dust test. It was decided that data on velocity pressure,
differential pressure, and temperature would be gathered
from the test modules every 10 sec.
Before obtaining the initial set of test data, it was
predicted the 3 year old membrane filters would have
the highest filter drag of the four modules. Due to the
normal seasoning of traditional PTFE membrane filter
bags throughout their life, this seemed like a reasonable
expectation. This normal seasoning occurs in part due to
the pore size of traditional PTFE membrane filters, relative
to the particulate size of the smaller fraction of baghouse
dust filtered in cement kiln baghouses. It was believed the
two new compartments of filters with standard drag filters
from suppliers 1 and 2 would be lower and likely in the
same range, as one another as they were purchased from
longstanding global credible filter suppliers. Lastly, it was
theorised that, due to a radically new membrane structure
optimised for a low-resistance/high-efficiency balance, the
GORE LOW DRAG filter bags would start with the lowest
filter drag.
The demonstration start-up and data
collection
The plant started up following the 2017 winter outage,
during which the new modules of test filter media and the
monitoring equipment were installed. The early trial data
proved to be consistent with the predictions of how each
of the filter media would perform. Shortly after the plant
was up and running, the first set of filter drag data was
collected from the plant’s central data acquisition system.
This data is plotted in Figure 4 and the initial filter drag
values can be seen in Table 2.
Figure 6. After 8 months in operation, the GORE LOW
DRAG filter bags compartment is dust free.
Table 2.
Initial filter drag data (gathered during the first month of the demonstration).
Compartment Filter media type
Life to date at the
beginning of the trial
Trendline Filter drag during the initial part of
the test (in. water/ft/min)
Module 6
Membrane supplier 1 3 years old
–
standard
drag
Blue
3.6
Module A
Membrane supplier 1 Brand new
–
standard
drag
Purple
2.2
Module 8
Membrane supplier 2 Brand new
–
standard
drag
Red
2.1
Module 9
Membrane supplier 2 Brand new
–
low drag Green
1.9
Table 3.
Filter drag data during the last two weeks of December 2017.
Compartment Filter
media type
8 months into trial
Trendline
Filter drag during the last two
weeks of December 2017 (in.
water/ft/min.)
Module 6
Membrane
supplier 1
3 years
–
8 month
old standard drag
Blue
4.0
Module A
Membrane
supplier 1
8 month old
–
standard drag
Purple
2.7
Module 8
Membrane
supplier 2
8 month old
–
standard drag
Red
2.8
Module 9
Membrane
supplier 2
8 month old
–
low
drag
Green
2.1
Figure 5. Filter drag trends from April 2017 – January 2018.