If 10,000 lbs/hr of airflow at 70°F is raised to 25,000°F, what is the equivalent SCFM, given the density of air at 70°F is 0.075 lbs/ft³?

• A. 1000
• B. 2222
• C. 1500
• D. 3000

Answer: (B)

To find the equivalent standard cubic feet per minute (SCFM) from a mass flow rate given in pounds per hour, you can follow these steps:

First, we need to convert the mass flow rate to a volume flow rate using the density of air at the reference temperature (which is 70°F in this case). The formula to convert mass flow rate to volume flow rate is:

[

\text{Volume Flow Rate (Cubic Feet per Hour)} = \frac{\text{Mass Flow Rate (lbs/hr)}}{\text{Density (lbs/ft³)}}

]

Given that the mass flow rate is 10,000 lbs/hr and the density at 70°F is 0.075 lbs/ft³, we can calculate the volume flow rate:

[

\text{Volume Flow Rate} = \frac{10,000 \text{ lbs/hr}}{0.075 \text{ lbs/ft³}} = 133,333.33 \text{ ft³/hr}

]

Next, to convert this volume flow rate from cubic feet per hour to SCFM, we need to note that SCFM represents the volume flow rate at standard conditions, typically at a pressure of 14.7 psi and