What Is the Packed Bed Absorption Column HTU-NTU Height Calculator?
The HTU-NTU method models continuous differential mass transfer columns where gas and liquid streams remain in uninterrupted contact along packing surfaces.
How Does the Packed Bed Absorption Column HTU-NTU Height Calculator Work?
NTU measures the degree of separation difficulty; HTU represents the physical packing efficiency; their product gives total required packing height.
Packed Bed Absorption Column HTU-NTU Height Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Z = N_{OG} imes H_{OG}, quad N_{OG} = rac{lnleft[ rac{y_1}{y_2}left(1 - rac{1}{A}
ight) + rac{1}{A}
ight]}{1 - rac{1}{A}}, quad A = rac{L}{m G}
Colburn dilute absorption equation for Number of Transfer Units and total packed bed height.
How to Use the Packed Bed Absorption Column HTU-NTU Height Calculator
- Input gas and liquid velocities, inlet/outlet solute mole fractions, equilibrium line slope m, and volumetric mass transfer coefficient.
Step-by-Step Example Calculation
Scrubbing VOC from Industrial Exhaust Stream
Input Values:
gasMassFluxKgM2S:1.6
liquidMassFluxKgM2S:3.5
inletGasMoleFractionY1:0.045
outletGasMoleFractionY2:0.004
equilibriumSlopeM:0.85
overallKogMolM3S:1.4
Worked Steps: Absorption factor A = 2.57, Transfer units N_OG = 2.92, HTU H_OG = 1.14 m, Packed height Z = 3.34 m.
Understanding Your Result
Displays required packing height Z in meters, number of transfer units N_OG, HTU in meters, and absorption factor A.
Factors That Affect the Result
- Operating with absorption factor A = L/(m*G) between 1.4 and 2.0 optimizes column height against solvent recirculation costs.
When Should You Use This Calculator?
- Air pollution wet scrubbers, amine acid gas sweetening, ammonia stripping, and bioprocess off-gas treatment.
Assumptions & Limitations
- Applies to dilute isothermal gas streams with linear Henry equilibrium solubility lines.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard chemical engineering mass transfer formulation.