This test program was designed to determine adequate sprinkler protection for empty intermediate bulk containers. A total of six tests were conducted investigating several parameters including; plastic pallet versus wood pallet IBCs, quick response versus standard response sprinklers, and the impact of storing the IBCs in a stacked IBC array or rack storage array. Where possible, the level of protection required was optimized.
4.1STACKED IBCS ON PLASTIC PALLETS
Three tests were conducted with empty IBCs on plastic pallets stacked 3-high below a 9.1 m (30 ft) ceiling. To begin this phase of the testing, an initial guess at the protection required was made based on the makeup of the IBC. Since the IBC on a plastic pallet is comprised of almost entirely exposed plastic (minus the wire cage), the initial protection was selected based on existing guidance for solid-piled uncartoned plastic in Data Sheet 8-9 [4].
Test 1 was conducted with K-factor 202 lpm/bar1/2 (14.0 gpm/psi1/2), quick response, 74 oC (165 oF) temperature rated, pendent sprinklers operating at 5.2 bar (75 psi). This pressure is between that required for uncartoned unexpanded plastic (3.5 bar [50 psi]) and uncartoned expanded plastic (6.9 bar [100 psi]). The design pressure of 5.2 bar (75 psi) resulted in a design density of 49 mm/min (1.2 gpm/ft2). During the test, a single sprinkler operated and controlled the fire. Based on this result, the system design pressure was reduced to optimize the required protection for the hazard.
Test 2 was conducted with the same K202 (K14) sprinkler, but the pressure was reduced to 2.2 bar (32 psi) which provided a design density of 33 mm/min (0.8 gpm/ft2). As with Test 1, a single sprinkler was able to control the fire. In an attempt to further reduce the system design pressure required, a third test was conducted at a lower pressure than used in Test 1 and Test 2.
Test 3 was conducted at a design pressure of 1.2 bar (18 psi) which provided a design density of 24 mm/min (0.6 gpm/ft2). In Test 3, six sprinklers operated and the fire was not contained within
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the test array. Fire traveled into the target IBCs and could potentially have traveled farther had additional commodity been provided.
The results from the tests conducted with stacked empty IBCs on plastic pallets are useful in determining the required protection for 3-high storage. Since two different test outcomes were obtained with two different design densities, the required protection was bracketed by Test 2 and Test 3. Adequate protection for the hazard can be achieved with K202 (K14) QR sprinklers operating at 2.2 bar (32 psi).
4.2STACKED IBCS ON WOOD PALLETS
The next phase of the test program was to determine the required protection for empty IBCs on wood pallets stacked 3-high below a 9.1 m (30 ft) ceiling. Since these IBCs have wood pallet bases, it was assumed that the hazard would be lower than that of the IBCs with plastic pallets. Based on that assumption, the adequate protection determined for Test 2 with IBCs on plastic pallets was expected to be adequate for IBCs on wood pallets.
Test 4 was conducted to determine if the level of protection provided in Test 3 (inadequate for IBCs on plastic pallets) would be adequate for the protection of IBCs on wood pallets. As with Test 1-3, the IBCs were stacked 3-high below a 9.1 m (30 ft) ceiling. Ceiling level protection was provided by K-factor 202 lpm/bar1/2 (14.0 gpm/psi1/2), quick response, 74 oC (165 oF) temperature rated, pendent sprinklers operating at 1.2 bar (18 psi). This provided the density of 24 mm/min (0.6 gpm/ft2) used in Test 3.
In Test 4, a single sprinkler operated and was able to control the fire. Based on the result from the test, two conclusions can be made. First, adequate protection of the hazard was provided with the K202 (K14) QR sprinklers operating at 1.2 bar (18 psi). Second, the result confirms that the hazard posed by the IBCs on wood pallets is less than that posed by the plastic pallet version.
Similar to the assumption that wood pallet IBCs were less hazardous than plastic pallet IBCs, metal pallet IBCs were considered to be even less hazardous. Therefore, the protection point
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obtained for the wood pallet IBCs was deemed adequate for the hazard of stacked IBCs on metal pallets. Further optimization of the level of protection was not attempted during this program.
4.3RACK STORAGE OF IBCS ON WOOD PALLETS
An additional test was conducted with rack storage of empty IBCs on wood pallets. As with previous tests, the ceiling height was set to 9.1 m (30 ft). The empty IBCs were stored in a double-row, open-frame rack that was 3-tiers high. The goal of the test was to determine adequate protection for the hazard, to add to the existing data set of rack storage tests in Data Sheet 8-9.
In Test 11, ceiling level protection was provided by K-factor 202 lpm/bar1/2 (14.0 gpm/psi1/2), quick response, 74 oC (165 oF) temperature rated, pendent sprinklers operating at 2.2 bar (32 psi). This provided the density of 33 mm/min (0.8 gpm/ft2). During the test, a single sprinkler operated and was able to control the fire.
The results show that adequate protection of the hazard was provided with the K202 (K14) QR sprinklers operating at 2.2 bar (32 psi). This was the last test of the project and no additional commodity was available for further testing. Therefore, optimization of this protection point was not attempted.
4.4SPRINKLER RESPONSE
One additional aspect of sprinkler protection was investigated during the project. Test 4 and Test 10 were conducted with identical storage arrays and the same design density [24 mm/min (0.6 gpm/ft2)], but with different sprinkler attributes. Both tests were conducted with empty IBCs on wood pallets stacked 3-high below a 9.1 m (30 ft) ceiling. In Test 4, adequate protection was provided by K202 (K14) quick response sprinklers at 1.2 bar (18 psi).
The goal of Test 10 was to determine if adequate protection could be provided by a lower K- factor standard response sprinkler. In Test 10, ceiling level protection was provided by K-factor
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161 lpm/bar1/2 (11.2 gpm/psi1/2), standard response, 68 oC (155 oF) temperature rated, pendent sprinklers operating at 1.9 bar (28 psi).
As expected, the time to first sprinkler operation was longer with the standard response sprinkler used in Test 10. This delay allowed the fire to become more involved in the array prior to the application of water. The roughly one minute delay allowed the fire to develop through the array, with the result that flames were beginning to impact the target IBCs prior to the first sprinkler operation. Additionally, a standard response sprinkler generally puts less water directly below the sprinkler where the fire is developing compared to a quick response sprinkler. The delay, plus the distribution pattern, caused the sprinkler to have little impact on the fire. Several additional sprinklers operated, but the damage exceeded the evaluation threshold prior to the sprinklers bringing the fire under control.
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