Detention Time Calculator
Calculate detention (retention) time for tanks, reactors, and treatment systems
Calculate Detention Time
Volume of the tank, vessel, or treatment system
Volumetric flow rate through the system
Detention Time Results
Formula used: DT = V / Q
Volume: 0.000 m³, Flow Rate: 0.000000 m³/min
Primary result: 0.00 hours
Application Analysis
Example Calculation
Three-Phase Separator
Volume: 2,100 ft³
Flow Rate: 15 MBPD (thousands barrels/day)
Conversion: 1 bbl = 4.211 ft³
Step-by-Step
1. Convert flow: 15,000 bbl/day × 4.211 ft³/bbl = 63,165 ft³/day
2. Apply formula: DT = 2,100 ft³ ÷ 63,165 ft³/day
3. Calculate: DT = 0.0332 days
Result: 47.9 minutes
Typical Detention Times
Seconds
Flash mixing chambers
Hydrocyclones
Distillation columns
Minutes
Flocculation basins
2-phase & 3-phase separators
Deaerators
Hours
Sedimentation tanks
Clarifiers
Reactors, oxidation ditches
Days
Wastewater ponds
Storage tanks
Long-term treatment systems
Design Tips
Ensure detention time matches process requirements
Consider flow pattern effects (plug vs mixed flow)
Account for dead volume in actual systems
Use consistent units throughout calculations
Understanding Detention Time
What is Detention Time?
Detention time (DT), also known as retention time or residence time, refers to the average amount of time that fluid is retained in a tank, reservoir, or system from the moment it enters until it flows out. It's the time it would take to fill or empty the system.
Why is it Important?
- •Ensures adequate contact time for reactions
- •Allows proper separation of phases by density
- •Maintains system hydraulic stability
- •Optimizes treatment efficiency
Formula Explanation
DT = V / Q
- DT: Detention time
- V: Volume of the vessel or tank
- Q: Volumetric flow rate
Note: This formula assumes perfect mixing. Real systems may have dead zones or short-circuiting that affect actual detention time.
Applications
- • Water and wastewater treatment
- • Chemical reactors and mixing tanks
- • Oil-water separators
- • Pharmaceutical processing
- • Food processing equipment