What is the detention time for a 400 gal mixing tank with a water flow of 15 pounds per minute?

To determine the detention time for a mixing tank, you can use the formula:

[

\text{Detention Time (hrs)} = \frac{\text{Tank Volume (gallons)}}{\text{Flow Rate (gallons per minute)} \times 60}

]

In this case, the tank volume is 400 gallons. The flow rate needs to be converted from pounds per minute to gallons per minute. Since water has a density of approximately 8.34 pounds per gallon, you can calculate the flow rate in gallons per minute as follows:

[

\text{Flow Rate (gallons/min)} = \frac{\text{Flow Rate (pounds/min)}}{\text{Density (pounds/gallon)}}

]

Substituting the values:

[

\text{Flow Rate (gallons/min)} = \frac{15 , \text{pounds/min}}{8.34 , \text{pounds/gallon}} \approx 1.80 , \text{gallons/min}

]

Now, plugging this flow rate back into the detention time formula:

[

\text{Detention Time (hrs)} = \frac{400 ,