Demineralizer Sizing Calculator

Plan cation and anion units with confidence today. Check loading rates, bed depth, and margins. Generate clean exports for approvals, procurement, and installation teams.

Inputs

Used as a practical ionic loading proxy for preliminary sizing.
Accounts for leakage limits, reserve, and operational conservatism.
Reset

Example Data Table

Scenario Demand (m³/day) Hours (h/day) Peak (%) TDS (mg/L) Trains Design run (h) Typical output highlights
Utility makeup 250 20 35 450 1 10 Design flow ≈ 16–18 m³/h, resin sized per ionic load.
Process skid 120 16 25 800 2 8 Smaller diameters per train, higher resin requirement from TDS.
Intermittent users 60 10 50 300 1 12 Peak-driven flow dominates; check service velocity limits.

Formula Used

This is a preliminary sizing method that treats feed TDS (as CaCO₃) as a single loading parameter. For final design, include CO₂, silica, alkalinity, temperature, and specified effluent quality.

How to Use This Calculator

  1. Enter your daily makeup demand and operating hours.
  2. Set peak and safety factors to match project conditions.
  3. Input feed TDS (as CaCO₃) from the latest water analysis.
  4. Choose the desired run time between regenerations.
  5. Adjust resin capacities and utilization to match vendor guidance.
  6. Set bed depth and maximum service velocity to reflect standards.
  7. Click Calculate to view results above the form.
  8. Export the summary using the CSV or PDF buttons.

Professional Article

1) Project uses and sizing objective

Demineralizers supply low‑conductivity water for boilers, pressure testing, and sensitive process packages. Correct sizing balances capital cost with regeneration frequency. This calculator converts site demand and operating hours into average and peak flows, then applies a safety margin to establish a design flow for equipment selection.

2) Loading estimate from feed chemistry

Feed chemistry drives resin consumption. For preliminary estimating, total dissolved solids expressed as CaCO₃ is treated as an ionic loading proxy. Converting mg/L to kg/m³ and multiplying by the planned production volume per run estimates ionic mass removed. Dividing by effective resin capacity—rated capacity multiplied by utilization—yields required cation and anion resin volumes.

3) Service flow, velocity, and vessel diameter

Hydraulics determine vessel diameter. Service flow per train is checked against a maximum superficial velocity to protect contact time and minimize channeling. Diameter is also checked against bed depth so the selected area can physically contain the resin volume. The calculator selects the governing area and reports resulting diameters for each train.

4) Bed depth, freeboard, and practical height

Height allowances ensure operability. Freeboard is sized as a percentage of bed depth to accommodate backwash expansion and prevent resin loss. Additional allowances for underdrains and distributors provide a practical shell height for early layouts and structural coordination, including platform elevations and access clearances.

5) Regeneration planning and design checks

Operational planning benefits from an estimated regeneration interval. Using average flow, the calculator estimates how many hours and days the cation bed can treat before exhaustion under the assumed loading and utilization. Treat this as a planning value; confirm final cycle time with vendor leakage curves, silica and CO₂ considerations, temperature effects, and neutralization or wastewater constraints.

To improve accuracy, use recent laboratory analysis and specify target product quality, such as conductivity, silica, and sodium limits. Consider pretreatment, temperature, fouling potential, and standby redundancy. When in doubt, select two trains for maintenance flexibility and safer commissioning schedules during critical milestones.

FAQs

1) Is TDS alone enough for final design?

No. TDS is a fast proxy for preliminary sizing. Final design should include alkalinity, CO₂, silica, temperature, specific ion balance, and required product quality targets.

2) Why do cation and anion resin volumes differ?

They use different chemistries and capacities, and the feed’s ion composition affects exhaustion. The calculator sizes each bed using its own effective capacity for planning.

3) What utilization factor should I choose?

Typical planning values are 0.65–0.85. Use lower values for strict leakage limits, variable feed, or when you want more operating reserve between regenerations.

4) How do I pick the design run time?

Select a run time that fits operations, neutralization, and discharge capacity. Longer runs reduce regeneration count but usually increase resin volume and vessel size.

5) What does maximum service velocity control?

It limits hydraulic loading through the bed. Exceeding it can reduce contact time and worsen performance. If velocity is high, add trains or increase vessel diameter.

6) Why is freeboard included in height?

Freeboard supports backwash expansion and reduces carryover risk. Height allowances also include underdrain and distributor space to reflect a practical shell estimate.

7) Can I use this for mixed-bed polishing?

Yes for early estimates, but mixed beds have different capacities and regeneration methods. Confirm polishing duty, resin data, and quality limits with the selected vendor.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.