EFFECT OF AIR VELOCITY ON CONVEYOR BELT FIRE SUPPRESSION SYSTEMS

J. H. Rowland III, NIOSH, Pittsburgh, PA

H. Verakis, MSHA, Triadelphia, WV

M. A. Hockenberry, MSHA, Triadelphia, WV

A. C. Smith, NIOSH, Pittsburgh, PA

ABSTRACT

Four different types of fire suppression systems were evaluated in

large-scale fire experiments to study the effect of air velocity on the

effectiveness to extinguish conveyor belt fires. The four different types

of suppression systems were water sprinkler, deluge type water spray,

and two different dry chemical fire suppression systems. The largescale fire tests were conducted with 72-in-wide fire resistant rubber belt

that met the Mine Safety and Health Administration flame resistant

requirement specified in Title 30, Code of Federal Regulations, Part

18, section 18.65 (also known as the 2G Flame Test). Each fire

suppression system was tested at air velocities of 500–550 feet per

minute (fpm) and 1350–1500 fpm. Two tests were conducted at both

air velocities for each fire suppression system. Both of the water-based

fire suppression systems were able to suppress the fire to the point

that a miner could extinguish it with a fire extinguisher. However, the

amount of water needed to suppress the fire to the point where a miner

could walk up to extinguish any smoldering belting was greater than

the current MSHA regulations require. MSHA regulations only require

10 minutes of water supply to the suppression system. In the test set

up neither of these systems would have suppressed the fire had the

water been turned off to the system after 10 minutes. The dry

chemical suppression systems produced mixed results. Dry chemical

suppression system A did not suppress the conveyor belt fire at either

air velocity. Dry chemical system B suppressed the fire at 500 fpm air

velocity, but produced mixed results at the higher air velocity. Details

are presented on the large-scale fire test set-up, arrangement of the

fire suppression systems, and conclusions regarding the effect of air

velocity on fire suppression system design and performance.

Disclaimer: The findings and conclusions in this report are those of

the authors and do not necessarily represent the views of NIOSH.

INTRODUCTION

On June 1, 2004, the underground coal mine ventilation safety

standards Code of Federal Regulations, Title 30, Part 75 became

effective for the use of a conveyor belt entry as an intake air course to

ventilate working sections. These standards, also known as the “Belt

Air Rule” contained a section which limited the air velocity in the

conveyor belt entry to no greater than 500 feet per minute (fpm) unless

otherwise approved by Mine Safety and Health Administration (MSHA)

in the mine ventilation plan with respect to fire suppression systems.

The “Belt Air Rule” included the requirement that air velocity be

compatible with fire suppression systems. This requirement was due

to the findings of the MSHA report on the VP 8 mine fire that occurred

on July 15, 2003 (MSHA, 2003). It was determined that the air

velocity at the belt drive where the fire started was in excess of 1,100

fpm and that the air velocity adversely affected the dispersion of the

dry powder chemical fire suppression agent during the fire. A mine

operator challenged the final rule of limiting the air velocity in the belt

entry in the Court of Appeals for the District of Columbia Circuit. The

Court granted the mine operator’s petition and vacated the requirement

on the air velocity cap (MSHA, 2005).

The removal of the air velocity cap from the final rule and the

requirement that air velocity be compatible with fire suppression

systems led to the need for research on the influence of high air

velocity on the performance of fire suppression systems in conveyor

belt entries. Test data was needed illustrating the relationship between

fire suppression system performance and air velocity, especially with

the increased use of wider belts in underground coal mines. To

address this issue, MSHA collaborated with the National Institute for

Occupational Safety and Health (NIOSH) on a research project to

obtain needed fire suppression performance data. Four different types

of fire suppression systems were evaluated in a large-scale fire tunnel;

a water sprinkler, deluge-type water spray, and two different types of

dry chemical fire suppression systems. The suppression systems are

representative of the types that are used in underground coal mines in

the United States. There are few dry chemical powder systems used

in underground coal mines in the United States. The dry chemical

powder systems are primarily used in place of water suppression

systems where temperatures are below freezing. The large-scale fire

tests were conducted using fire-resistant rubber belt, 72-inches in

width that met Title 30, Code of Regulations, Part 18, section 18.65.

Each fire suppression system was tested at air velocities of 500 – 550

fpm and at 1350 – 1500 fpm. A minimum of two tests were conducted

at both air velocities for each fire suppression system. Both the water

sprinkler and deluge-type water spray systems suppressed the fire to

the point where a miner could extinguish it with a fire extinguisher.

However, the amount of water needed to suppress the fire to the point

where a miner could walk up to extinguish any smoldering belting was

greater than the current MSHA regulations require. MSHA regulations

only require 10 minutes of water supply to suppression system. In the

test set up neither of these systems would have suppressed the fire

had the water been turned off to the system after 10 minutes. Dry

chemical suppression system A did not suppress the conveyor belt fire

at either air velocity. Dry chemical system B suppressed the fire at the

lower air velocity but produced mixed results at the higher air velocity.

Details are presented on the large-scale fire test set-up, arrangement

of the fire suppression systems, and conclusions regarding the

influence of air velocity on fire suppression system design and

performance.

FIRE SUPPRESSION FACILITY

All the experiments were conducted at the NIOSH Fire

Suppression Facility (FSF). The FSF, shown in figure 1, is a full-scale,

state-of-the-art fire test facility located on the surface at the Lake Lynn

Laboratory which is located approximately 60 miles southeast of

Pittsburgh, Pennsylvania. The fire tunnel is tee-shaped to simulate a

main entry and crosscut. The main entry is 153-ft long and the

crosscut is 40-ft long. Each entry is 18-ft wide and 7-ft high. The roof

is made of corrugated steel bridge planks with the interior of the roof

coated with 2-in-thick fire resistant material. The ribs are made of 8-inthick solid concrete blocks coated with 1 in fire resistant material. The

floor of the FSF is made of reinforced concrete. A 6-ft diameter

variable speed axial vane fan is located at one end of the tunnel to

provide ventilation. The fan has a pneumatic controller to adjust the

fan blades in order to increase or decrease the air velocity. The fan

can produce an air velocity over the cross-section of the entry of 1500

fpm. As a point of reference, distances were measured from the fan to

the exit of the tunnel, and the fan is designated as the 0-ft mark except

where noted. The crosscut area and main entry are instrumented with
thermocouples. The thermocouples in the main entry protrude down

from the roof approximately 1.2 in and are spaced 10 ft apart down the

center line starting 10 ft from the fan to the end of the entry. Also a 9-

point thermocouple array was set up 150 ft from the fan across the

width and the height of the entry to measure the temperature of the

gas as it exited the entry. These array thermocouples were attached

to three vertical 1⁄2-diameter steel pipes spaced evenly across the width

and were positioned evenly across the height of the entry and from the

roof to the floor.

Figure 1. Fire Suppression Facility.

To measure the gas components produced from a belt burn test,

a 4-point gas monitoring array was set up at the open end of the

tunnel. The array was made of 1⁄2-in diameter black steel pipe

positioned at the center of the entry. A total of four 1/8-in holes were

drilled into the vertical section of the pipe to sample the gases. The

sample holes are equally spaced vertically from the roof to the floor. A

1⁄2 -in tube was connected to the steel pipe and led back to the control

room to a set of infrared gas analyzers. The gas analyzers measure

carbon monoxide (CO), carbon dioxide (CO2), and oxygen (O2) gas

concentrations. The gas concentrations were collected every 2

seconds and were recorded by a computer based data acquisition

system.

The FSF was equipped with two video cameras to record the test

burn. The first camera was mounted on the roof roughly 75 ft from the

fan in the center of the roof. The video camera was connected into a

video recorder and a monitor inside the control room which gave a

frontal view of the conveyor belt structure during the belt burn test.

The second video camera was placed on a stand on the left side of the

tunnel, when facing the open end of the tunnel, upstream from the

conveyor belt structure. This camera was connected to a separate

video recorder and a monitor inside the control room to view the inside

of the conveyor belt drive area where the belt was ignited. The FSF

has a 5000 gallon closed water system that was used to supply water

to the water sprinkler and deluge-type water spray suppression

systems.

The conveyor belt structure is located 85 ft from the fan and is

slightly off center of the entry to allow for heavy equipment to pass on

one side to place the belting onto the structure. The conveyor belt

structure is 50-ft long and 7.25-ft wide. Fifty-five gallon steel drums are

used to simulate the head roller, drive rollers, idler roller and take-up

rollers. The diameter of each drum is 2-ft wide and each drum is 5.6-ft

long. On each end of the drum a steel plate is welded with a 5-in hole

cut out of the center of the drum to allow for a 4-in diameter steel pipe

to be inserted through the center of the drum. The 4-in diameter pipe

is then attached to the structure as shown in figure 2. The trough

idlers are 5-in in diameter and are placed at 5 ft intervals.

Figure 2. Fifty-five gallon drum as drive roller.

To ignite the belt, four sets of natural gas impingement burners

connected in series were placed approximately 6 in below the belt

along the width of the belt next to the drive roller closest to the fan, as

shown in figure 3. Each burner was equipped with 60 stainless steel

jets and had a rated output of 44 to 114 kilowatts. The ignition region

was confined by metal shields on 3 sides, with the fourth side

unshielded toward the open end of the fire tunnel to reduce the effect

the ventilation may have had on the ignition process.

Figure 3. Natural gas burners to ignite belt.

TEST PROCEDURE

A 6-ft wide fire resistant rubber belt that meets 30 CFR Part 18.65

was installed on the conveyor belt structure shown in figure 4.

Typically the length of the belt ranged from 140 ft to 165 ft.

Thermocouples were installed on the belt starting from the head roller

in the center and on each edge of the belt on 10-ft intervals. Each

thermocouple was placed just below the surface of the belt to measure

the belt temperature. Depending on which fire suppression system

was tested, additional thermocouples were placed on the sensors used

to detect the fire. For example the dry chemical fire suppression

system A used 3 point-type heat sensors to detect the fire, so

thermocouples were placed on the end of each point-type heat sensor

to determine which sensor activated the suppression system and at

what temperature. In the case of the water sprinkler fire suppression

system, thermocouples were place on the sprinkler heads in the area

where the fire would most likely activate the sprinkler.

To determine the air velocity for the test a hand held vane

anemometer was positioned over the top belt over the drive area in the

center of the belt and approximately 1 ft from the roof. Two

measurements were taken and averaged together. Each

measurement had to be within 10 percent of the each other before

recording the average as the air velocity. As mentioned previously, a

9-point thermocouple array was set up 150 ft from the fan across the

cross section area of the entry to measure the temperature of the air

as it exited the entry and the air velocity was measured at each of the

nine points where the thermocouples were located. The exit air

velocities at each point were averaged together and recorded as the

exit velocity. It is important to mention that once the air velocity was
determined for the test, at no time was the fan turned off or adjusted

until the test was completed.

Figure 4. Test Set Up.

To ignite the belt, four natural gas burners connected in series

were mounted about 6 in underneath the belt drive roller across the

width of the belt. The gas burners were ignited with a propane torch.

The natural gas was left on for 10 minutes before it was turned off.

Visual observation looking at the monitor in the control room or through

the side window portal on the tunnel was used to determine if the belt

remained ignited after the gas was turned off. If it appeared that the

conveyor belt fire was not self-sustaining, the gas was turned back on

to the burners until the belt was on fire and the fire was able to sustain

itself. In a few cases, the fire suppression system detected the fire and

activated before the end of the 10 minute ignition period. In this case

once the fire suppression system alarmed, the gas supply to the

burners was immediately shut off.

Each fire suppression system was installed according to the

manufacture’s instructions or recommendations and, as applicable,

was armed before the conveyor belt was ignited. Once the fire

suppression system detected the fire and was activated, the fire was

monitored from inside the control room to determine if or when the fire

was extinguished or under control. For the water sprinkler and delugetype spray tests, the water was left on until it was visually determined

the fire was extinguished. Subsequent to the fire suppression test,

hand held 5-gallon water extinguishers were used to extinguish the

remaining fire remnants.

FIRE SUPPRESSION SYSTEM SET INSTALLATION

Four different types of fire suppression systems were evaluated in

study, a water sprinkler suppression system, a deluge-type water

ay suppression system and two different dry chemical powder

ems. The set-up for the water sprinkler fire suppression system

he conveyor structure required 16 sprinklers to cover the 50 ft of

cture. The spacing for the sprinkler system was at intervals of 8 ft

ccordance with 30 CFR 75. 1101-8. The reference point was the

er of the head roller. The first sprinkler, which is denoted as

nkler 1 in figure 5, was located 2.3 ft from the center head roller, 62

ertically from the floor, and 48 in over the center of the belt. The

vation temperature of each sprinkler was 286° F. A thermocouple

placed on each sprinkler head to determine which sprinkler

vated and the time of activation during the test.

The set-up for the deluge-type water spray fire suppression

em required a total of 28 nozzles to protect 50 ft of belt structure.

ke the sprinkler fire suppression system, where the sprinklers were

ed over the center of the belt, the deluge-type water spray system

uires 14 nozzles along one side of the structure and 14 on the

osite side of the structure. The deluge-type water spray system

set up in accordance with 30 CFR 75. 1101-1. Detection and

ation of the system was achieved by 5-point-type heat sensors that

strategically placed on the structure based on 30 CFR 75 and with

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the collaboration of the manufacturer. A thermocouple was placed on

each sensor to determine which sensor activated the system. The

activation temperature for the point-type sensor was 165° F. Once the

activation temperature was reached by any one of the five sensors, the

deluge-type valve was manually opened and water flowed to all 28

nozzles. The location and spacing of the nozzles and sensors are

shown in figure 6.

Figure 5. Water Sprinkler System.

Figure 6. Deluge Water Spray System.

For the dry chemical powder fire suppression system A, the

manufacturer determined that a total of 40 nozzles were needed to

protect 50 ft of structure. Just like the deluge-type water spray

suppression system, half (20) of the nozzles were arranged to protect

one side of the structure and the other half (20) were arranged to

protect the opposite side of the structure. The dry chemical powder

used was ABC powder extinguishment agent. This system has a

nominal weight of 300 pounds (lbs) of ABC powder. To activate the

system, 3-point-type heat sensors were strategically located on the

structure based on 30 CFR 75 and with the collaboration of the

manufacturer. The activation temperature for each point-type sensor

was 286° F. A thermocouple was attached to each point-type sensor

to determine which one activated the system. Once the fire was

detected and the system activated, ABC powder was simultaneously

dispersed through all 40 nozzles. The location and spacing of the

nozzles and point-type heat sensors are shown in figure 7. One

important note to mention is that these systems must be designed for

each particular installation. For these tests, a representative from the

company designed the nozzle installation based on this configuration

set-up.
Figure 7. Dry Chemical Fire Suppression System “A”.

For the second dry chemical fire suppression system, B, the

manufacturer determined that a total of 64 nozzles were needed to

protect the 50 ft of structure. Just like dry chemical system A, half of

the nozzles protected one side of the structure and the other half

protected the opposite side of the structure. This system also used an

ABC powder extinguishment agent. This system required a nominal

weight of 500 lb of ABC powder to protect 50 ft of structure in this set

up. To detect that a fire was present, system B did not use point-type

heat sensors, but instead it used a linear heat detection wire. The wire

was mounted along the outside of the structure 72 in above the

ground. The activation temperature for the linear heat detection wire

was 356° F. Once the fire was detected and the system was activated,

ABC powder was simultaneously dispersed through all 64 nozzles. A

representative from Company B designed and installed the

suppression system on the conveyor belt structure. The location and

spacing of the nozzles are shown in figure 8.

Figure 8. Dry Chemical Fire Suppression System “B”.

RESULTS AND DISCUSSION

The results for all tests at 500-550 fpm are shown in table 1 (see

Appendix), while the results from tests at 1350-1500 fpm are shown in

table 2 (see Appendix). The results of the water sprinkler suppression

tests showed for this set-up the system stopped the flames from

spreading out of the drive area and suppressed the fire at both 500

and 1500 fpm air velocities. At 500 fpm, only the number 8 sprinkler

located between the belts near the ignition area activated. At the 1500

fpm air velocity sprinkler number 10 activated first followed by sprinkler

8. The number 10 sprinkler most likely activated first because the

higher air flow pushed the heat down stream from the ignition area,

where sprinkler 8 was located. The heat release rate at the time of

activation was significantly higher at the high air velocity than the lower

air velocity because more belting was involved in the fire before

sprinkler 10 activated. The heat release rate is computed by the

following equation:

Qtotal = Cp x ρo x Ve x Ao x ΔT

where Cp = heat capacity of air,

ρo = density of air,

Ve = air velocity,

Ao = entry cross section area, and

ΔT = exit temperature – initial temperature.

The heat release rate was calculated based on exit-gas

temperatures, rather than gas concentrations because the gas

concentrations were not available for the entire test suite. Based on

previous research conducted by the Bureau of Mines, the temperature

based heat release rate calculation is typically about 50 percent less

than the average value calculated using carbon monoxide and carbon

dioxide produced from the combustion process and the oxygen

consumed in the combustion process (Litton, DeRosa, and Li, 1987).

This is due to heat loss to the structure and the surrounding

environment.

It should be noted that in this test series, the water supplying the

suppression system was not turned off until 40 to 50 minutes to make

sure the fire was suppressed to the point that any small residual pieces

of belting that were smoldering could be extinguished with a water

extinguisher. However, based on MSHA regulations the supply of

water had to be adequate to provide a constant flow of water for 10

minutes with all sprinklers functioning based on 30 CFR 75 1101-8. If

the water flow would have been turned off after 10 minutes, it is

unlikely that the water sprinkler suppression system would not have

suppressed the fire, based on visual observations.

The results of the deluge-type water spray suppression tests

showed that for this configuration the suppression system stopped the

flames from spreading out of the drive area and suppressed the fire. In

the lower air flow tests, point-type heat sensor D activated the system

while in the high air flow tests there were mixed results. In the first

test, sensor D activated the system while in the second test, sensor C

activated the system. The heat release rates were slightly higher at the

lower air velocity versus the higher air velocity. The water supply to

the deluge-type water spray suppression system was not turned off

until about 30 to 50 minutes. The MSHA regulations for deluge-type

water spray systems require that the water supply shall be adequate to

provide flow for 10 minutes, an exception is that pressure tanks maybe

used as a source of water supply, and shall be of 1000-gallon capacity

for a fire-resistant belt. Also 3000 gallons for a nonfire-resistant belt

may be provided (U.S Code of Federal Regulations 30CFR 75 1101-

3). If the water to the system would have been turned off after 10

minutes, it is unlikely that the fire would not have been suppressed.

The dry chemical fire suppression system A did not suppress the

fire at either air velocity. There were two major issues with this

suppression system, the time it took to detect the fire and the durability

of the hoses. The delay in detection of the fire resulted in a number of

the hoses supplying suppressant agent to the nozzles to be damaged

by the fire. If the fire was detected sooner, the fire would have been

smaller, therefore imposing less damage on the hoses. In both of the

tests, several of the nozzles didn’t disperse any dry chemical agent on

to the belt because they were damaged by fire. In the lower air flow

test, the nozzles that were affected were 5, 6, 7, 8, 16, 18, 19, 20, 24,

31, 33, 34, 35, and 36. Looking at figure 7 all of these nozzles were

controlled by the two 125-lbs tanks. The two 25-lb tanks functioned

properly because the entire dry chemical agent was dispersed on to

the belt. In the high air flow test, there were fewer nozzles that didn’t

disperse compared to the low air velocity test. The nozzles affected

were 22, 24, 28, 34, and 35. The main hose from the 125-lb tank on

the opposite side of the structure was damaged so none of the dry

chemical agent from that tank was discharged on to the belt. The

three remaining tanks functioned properly dispersing the dry chemical

agent onto the belt. In one test at the lower air velocity sensor B
activated the suppression system, while on the other test sensor C

activated the system. At the higher air velocity the same result was

repeated, in one test sensor B activated the suppression system while

sensor C did for the other test.

The dry chemical fire suppression system B produced mixed

results. In the lower air velocity tests, the fire suppression system

completely extinguished the fire. In the higher air velocity tests, the fire

was completely extinguished in one of the tests, but was not

extinguished in the second test. It should be noted that the fire size for

the second test was much larger than the other tests. This may have

been due to the wear factor of the belting. Also, ambient conditions

such as air temperature and humidity may have contributed to the

difference. In the test where the fire was not extinguished, one of the

tanks did not function properly, resulting in nozzles 16 through 32 not

discharging any dry chemical on to the belt. However, the location of

these nozzles shows that this powder would not have contributed to

extinguishing the fire because they are downstream of the fire in the

test set-up. Unlike the dry chemical suppression system A, the hoses

for the dry chemical fire suppression B were not damaged during the

test. The malfunction occurred in the tank activation mechanism. The

system used a linear heat detection system to activate the system. It

was not possible to determine the specific location on the linear

detection wire that activated the system in any of the tests.

CONCLUSION

Four different types of fire suppression systems were tested

under two air-velocity conditions, 500-550-fpm and1350-1500-fpm.

Two water-based suppression systems, a water sprinkle and a delugetype water spray, were able to suppress the fire under the test

conditions in this set-up. However, the amount of water needed to

suppress the fire to the point where a miner could walk up to extinguish

any smoldering belt was greater than the current MSHA regulations

require. MSHA regulations only require 10 minutes of water supply to

the suppression system. In this test set-up, it is unlikely that either of

these systems would have suppressed the fire had the water been

turned off to the system after 10 minutes, based on visual observation.

The two dry chemical suppression systems provided mixed

results. The dry chemical fire suppression system A did not extinguish

the fire in either air-velocity condition. This system uses a nominal

weight of 300 lb of dry chemical agent and 40 nozzles to protect 50 ft

of fire resistant conveyor belt. The primary failure mechanism was

damage to the hoses from the fire prior to system activation. Several of

the nozzles in system A did not discharge any dry chemical agent

because the hoses leading to the nozzles were severely damaged by

the fire. The dry chemical fire suppression system B performed well at

the lower air velocity; however, at the higher air velocity mixed results

were obtained. Dry chemical fire suppression system B required a

nominal weight of 500 lb of dry chemical agent and 64 nozzles to

protect 50 ft of fire resistant conveyor belt. One of the higher air

velocity tests resulted in the fire not being extinguished. In addition

there was a malfunction with one of the four dry chemical supply tanks,

resulting in one tank not discharging any dry chemical to the connected

nozzles. This malfunction, however would not have affected the

extinguishment of the fire, because the nozzles were located outby

(downwind) of the fire area.

The large-scale testing indicated that the air velocity does in fact

have significant effect on the detection, activation, and suppression

capabilities of the fire suppression system. The water-based fire

suppression systems each performed well under both sets of airvelocity conditions, but required more time than the 10 minute

requirement in 30 CFR. The dry chemical systems, however, did not

perform as well, and resulted in failure to extinguish the test fires in

some experiments. Several factors may have contributed to the dry

chemical system not performing well under these large-scale test

conditions. The ventilation rate not only affects the discharge pattern

of the dry-chemical agent, but also contributed greatly to the detection

and actuation of the system. The increased air velocity condition had a

cooling effect on the detection systems which would have allowed the

fire to grow and propagate further before the system detected and

actuated the dry chemical. The importance of early detection was

imperative for any fire condition. The higher air velocity tests may

have actually been larger fires by the time the system discharged,

resulting in a more challenging suppression. A combination of the

larger fire conditions under high air velocity because of detection

cooling, detection location, the transference of dry chemical by the

ventilation, and overall fire suppression system design, all may have

impacted and affected the performance of each system. NIOSH will

conduct research to improve fire suppression systems by evaluating

new technologies, new nozzle designs, spacing of nozzles, and system

activation temperature.

ACKNOWLEDGMENT

The authors would like to thank our colleagues at NIOSH

Pittsburgh Research Laboratory and Lake Lynn Laboratory and the

contractors from Ki for conducting and setting up the experiments.

REFERENCES

Mine Safety and Health Administration, 2003. Coal Mine Safety and

Health, Report of Investigation, Underground Coal Mine Fire,

Non-Injury Mine Fire Accident, April 9 & 10, 2003, VP8, I.D. 44-

03795, Island Creek Coal Company, Mavisdale, Buchanan

County, Virginia, District 5, P.O. Box 560, Wise County Plaza

Norton, Virginia. July 15, 2003. 31 pages.

Mine Safety and Health Administration, 2005. Program Information

Bulletin NO. P05-14 July 27, 2005.

Litton, C., DeRosa, M, and Li, J., 1987, Calculating Fire-Throttling of

Mine Ventilation Airflow, Report of Investigations 9076, U.S.

Bureau of Mines.

U.S. Code of Federal Regulations, 30 CFR 75. 1101-3.
Table 1. All test results for 500 – 550 fpm.

APPENDIX

Air Velocity

Total Duration Time

of Gas Flow ato

Burners

Time System Activated Fire Size at Activations Result

fpm Minutes:seconds Minutes:seconds Megawatts

Sprinkler Test 1 (1) 532 14:00 37:50 0.7 Positive

Sprinkler Test 1 513 14:00 36:06 0.7 Positive

Deluge Water Test 1 (2) 522 15:00 33:03 1.5 Positive

Deluge Water Test 1 503 15:00 23:14 1.2 Positive

Dry Chemical System A Test 1 540 15:00 18:08 4.9 Negative

Dry Chemical System A Test 2 530 13:56 13:56 6.0 Negative

Dry Chemical System B Test 1 540 07:07 07:07 0.2 Positive

Dry Chemical System B Test 2 524 13:28 13:28 0.2 Positive

Positive - suppressed fire under these test conditions

Negative - did not suppress the fire under these test conditions

(1) Burners turned off after 10 minutes then turned back on at the 23.0 minute mark for 4 additional minutes

(2) Burners turned off after 10 minutes then turned back on at the 19.5 minute mark for 4 additional minutes

(3) Burners turned off after 10 minutes then turned back on at the 18.5 minute mark for 4 additional minutes

Table 2. All test results for 1350 – 1500 fpm.

Air Velocity

Total Duration Time

of Gas Flow ato

Burners

Time System Activated Fire Size at Activations Result

fpm Minutes:seconds Minutes:seconds Megawatts

Sprinkler Test 1 (1) 1488 10:00 13:42 5.5 Positive

Sprinkler Test 1 1499 13:00 34:04 2.3 Positive

Deluge Water Test 1 (2) 1427 12:00 20:38 2.6 Positive

Deluge Water Test 1 1411 15:00 20:12 1.7 Positive

Dry Chemical System A Test 1 1478 14:31 14:24 1.1 Negative

Dry Chemical System A Test 2 1494 13:01 13:01 4.4 Negative

Dry Chemical System B Test 1 1367 13:31 13:31 4.6 Positive

Dry Chemical System B Test 2 1397 15:00 19:13 10.8 Negative

(4) Burners turned off after 10 minutes then turned back on at the 18.5 minute mark for 5 additional minutes