Calculator inputs
What this tool estimates
It sizes the bed volume, media mass, column diameter, bed depth, service time, treated bed volumes, and pressure drop.
Design approach
The model combines EBCT sizing, adsorption capacity, hydraulic loading, safety factor, and an Ergun pressure drop check.
Export support
Use the built in buttons to save a structured CSV summary or a simple engineering report in document format.
Example data table
| Case | C₀ (mg/L) | Cₜ (mg/L) | Q (m³/h) | EBCT (min) | q (mg/g) | ρb (kg/m³) | Velocity (m/h) | Bed volume (m³) | Diameter (m) | Bed depth (m) | Service time (h) | Pressure drop (kPa) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Base design | 120 | 10 | 8 | 12 | 280 | 480 | 12 | 1.60 | 0.92 | 2.40 | 187.97 | 2.66 |
| Higher flow | 120 | 10 | 12 | 12 | 280 | 480 | 12 | 2.40 | 1.13 | 2.40 | 187.97 | 2.66 |
| Deeper contact | 120 | 10 | 8 | 18 | 280 | 480 | 12 | 2.40 | 0.92 | 3.60 | 281.96 | 4.00 |
Formula used
1) Required removal
Removal (%) = ((C₀ − Cₜ) / C₀) × 100
2) Bed volume from contact time
Bed volume (m³) = Q × (EBCT / 60)
3) Media mass
Adsorbent mass (kg) = Bed volume × Bulk density
4) Contaminant loading
Load (g/h) = Q × (C₀ − Cₜ)
5) Usable cycle capacity
Usable capacity (g) = Adsorbent mass × q / Safety factor
6) Service time
Service time (h) = Usable capacity / Contaminant load
7) Column diameter and bed depth
Area = Q / Superficial velocity and Diameter = √(4 × Area / π) and Bed depth = Bed volume / Area
8) Pressure drop check
ΔP/L = 150(1−ε)²μu/(dp²ε³) + 1.75(1−ε)ρu²/(dpε³) using the Ergun equation.
These calculations give fast preliminary sizing. Final equipment selection should also verify adsorption isotherms, mass transfer limits, breakthrough testing, vessel code requirements, and distributor details.
How to use this calculator
- Enter influent and target effluent concentrations.
- Provide process flow and desired contact time.
- Insert media capacity and packed bulk density.
- Choose a safety factor for conservative design.
- Set superficial velocity, void fraction, and particle size.
- Enter fluid viscosity and density for pressure drop estimation.
- Submit the form to view results above it.
- Review diameter, bed depth, service time, and pressure drop.
- Use the export buttons to save your design summary.
Frequently asked questions
1) What does EBCT control in this design?
EBCT controls the empty bed volume needed to give the fluid enough contact time with the adsorbent. Larger EBCT values increase media volume and often improve removal reliability.
2) Why is a safety factor included?
A safety factor reduces the usable adsorption capacity in the calculation. It helps cover uncertainty from isotherm variation, fouling, mass transfer limits, aging, and field operating swings.
3) Is the service time an exact breakthrough prediction?
No. It is a screening estimate based on capacity and load. Detailed breakthrough behavior still depends on kinetics, temperature, competing species, and full scale column test data.
4) Why does pressure drop rise with smaller particles?
Smaller particles create tighter flow paths. That increases friction and inertial resistance across the bed, which raises pressure drop even when adsorption performance may improve.
5) Should I trust the diameter result directly?
Use it as a preliminary sizing value. Final vessel diameter should also consider internals, wall thickness, distributors, nozzle layout, allowable pressure loss, and fabrication standards.
6) What does bed volumes treated per cycle mean?
It shows how many empty bed volumes pass through the column before the estimated service limit is reached. Engineers often use this value to compare design options quickly.
7) Can I use this for gas phase adsorption?
The structure is most suitable for liquid phase preliminary sizing. Gas systems need careful treatment of compressibility, residence time, density changes, and sorption behavior.
8) When should pilot testing be added?
Pilot testing is valuable when contaminants are mixed, capacities are uncertain, influent varies strongly, or the design has strict compliance targets with expensive media replacement risk.