Answer:
To determine the minimum number of portable fire extinguishers required for the plant, we need to follow the guidelines set out by NFPA 10.
Step 1: Determine the floor area of the plant
The estimated floor area per floor is 150m x 75m = 11,250 m²
Therefore, the total floor area of the plant is 3 x 11,250 m² = 33,750 m²
Step 2: Determine the maximum travel distance to an extinguisher
According to NFPA 10, the maximum travel distance to an extinguisher should not exceed 30 meters. Since the distance between each floor is about 8 meters, we need to place fire extinguishers on each floor.
Step 3: Determine the minimum number of extinguishers required
We need to calculate the minimum number of extinguishers required for each floor, using the formula:
Minimum number of extinguishers = (Floor area / Maximum travel distance to an extinguisher) x (1/75% of floor area covered by an extinguisher)
For the 1st and 2nd floors, the minimum number of extinguishers required is:
Minimum number of extinguishers = (11,250 m² / 30 m) x (1/75%) = 150 x 1.33 = 200
Therefore, we need a total of 200 extinguishers for each of the 1st and 2nd floors.
For the ground floor, we need to add an extra 10% of extinguishers for protection of high hazard areas, such as those containing electrical equipment. Therefore, the minimum number of extinguishers required for the ground floor is:
Minimum number of extinguishers = (11,250 m² / 30 m) x (1/75%) x 1.1 = 165 x 1.33 x 1.1 = 246
Therefore, we need a total of 246 extinguishers for the ground floor.
Overall, we need a total of 200 + 200 + 246 = 646 portable fire extinguishers for the plant