405 (16)
236 (500)
472 (1000)
455 (18)
295 (625)
590 (1250)
510 (24)
354 (750)
708 (1500)
The air flow rates listed above are at 0.25 seconds
residence time.
Care should be taken to maintain residence time of
air passing through the carbon adsorber. For
example, placing two adsorbers in series maintains
the residence time while doubling the airflow
capacity.
At 472 sL/s (1,000 scfm) the ASZM-TEDA adsorber uses
a 12 x 30 mesh of carbon media that has a pressure
drop of approximately 1,500 pascals (6 inches wg)
per carbon adsorber stage. Activated carbon
adsorbers, conforming to ASME AG 1 and using 8 x 16
mesh carbon, have a pressure drop of approximately
682 pascals at 472 sL/s (2.75 inches wg at 1,000
scfm) per carbon adsorber stage.
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Carbon adsorbers shall consist of six 50 mm 2 inch thick panels configured
as a V-bed similar to the shape of a Type I cell per IEST RP-CC-008. The
adsorber shall consist of [ASZM-TEDA carbon conforming to EA-DTL-1704]
[non-impregnated highly activated carbon conforming to ASME AG 1, Section
FF]. The carbon adsorber shall meet the requirements for airflow
resistance, refrigerant leak test, and dimethylmethylphosphonate (DMMP)
breakthrough life test, moisture content, cyanogen chloride (CK) gas life,
gas life capacity testing. The carbon adsorber shall have an airflow rate
capacity as indicated and be designed to adsorb chemical vapor with an
overall system minimum residence time of [0.25] [______] seconds. All
inner and outer case materials shall be ASTM A 240/A 240M Type 304
stainless steel. [The adsorber design shall include a means to obtain
samples of the adsorbent. The preferred method incorporates a set of
sample canisters. Other methods or designs are acceptable if it can be
shown that a representative sample of the total bed thickness is produced
without voids or that result in a bypass condition.] Carbon adsorber
frames shall have an integral perimeter [gasket seal] [fluid seal].
2.4.4.1
Airflow Resistance
The airflow resistance shall be [750 Pascal 3.0 IWG +/- 10%] [1,500 Pascal
6.0 IWG] [[_____] Pascal IWG +/- 10%] at the rated air flow with an air
stream temperature of 21 degrees C 70 degrees F and a barometric pressure
of 760 mm 29.92 inches Hg. Each cell to be delivered to the Purchaser
shall have been tested by the manufacturer prior to packaging. Airflow
resistance and certification shall be marked on each cell. Any cell not
meeting the airflow resistance requirement shall be rejected. The cell
shall be installed in the test tunnel in its service orientation and the
airflow through the cell adjusted to [236 L/s 500 SCFM +/- 5%] [472 L/s
1,000 SCFM +/- 5%] [[_____] L/s SCFM +/- 5%]. The following shall be done:
1) Record the barometric pressure. 2) Measure and record the air stream
temperature. 3) Determine and record the difference in the static pressure
head upstream of the cell to that downstream of the cell. The test fixture
resistance must be subtracted so that the recorded resistance is that of
the cell. If testing occurs at nonstandard conditions, the airflow
resistance shall be calculated and recorded, and the test measurements
SECTION 15860A
Page 12
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