In modern hydrometallurgical operations (Electrorefining and Electrowinning), electrolytic cells are subject to harsh operational demands. They must hold tens of tonnes of corrosive electrolyte, support massive vertical electrode loads (anodes and cathodes), and withstand thermal, hydrostatic, and potential seismic forces over a service life of 20+ years.
At PRS (Precision Technology), we utilize advanced Finite Element Analysis (FEA) to simulate real-world physical and mechanical conditions before a single electrolytic cell is cast. This rigorous engineering approach guarantees structural reliability, eliminates local stress concentrations, and prevents catastrophic leaks or structural failures.
In this technical blog, we walk through the FEA calculation methodology, boundary conditions, load cases, and stress/displacement results for our Vinyl Ester Resin Concrete Monolithically-Cast Electrolytic Cells.
1. Material Properties & Modeling Scope
Our FEA study focuses on two main configurations: the Intermediate Electrolytic Cell and the End Electrolytic Cell.
Both cell types are monolithically cast using high-performance vinyl ester polymer concrete, providing exceptional corrosion resistance and high mechanical strength compared to traditional materials.
Key Material Specifications
Polymer Concrete Material: Vinyl Ester Resin Concrete
Modulus of Elasticity (Bending): 16,671 MPa
Specific Gravity: 2,210 kg/m³
Ultimate Compressive Stress: 53.9 MPa
Ultimate Bending Stress: 23.9 MPa
Electrolyte Specific Gravity: 1.3 kg/m³
2. Realistic Boundary Conditions & Contact Modeling
Accurate boundary condition modeling is critical to achieving trustworthy simulation results.
Static Condition (Adjacent Cell Interaction)
In actual tankhouse layouts, electrolytic cells sit in long, contiguous rows. Adjacent cell walls touch at specified contact regions, providing horizontal support and reaction forces.
- Nonlinear Contact Analysis: Rather than artificially bonding contact points, our simulation establishes realistic contact surfaces that rest directly on support blocks. These support blocks provide positive vertical reaction forces without negative suction, accurately reflecting real-world installation.
Seismic Condition (Worst-Case Analysis)
During a seismic event, top inter-cell contacts may momentarily separate. To ensure maximum safety margins, our Seismic Load Model releases top contact connections and relies solely on bottom support boundaries to simulate the absolute worst-case loading scenario.
3. Applied Loads & Load Combination Cases
Our linear stress analysis evaluates tetrahedral meshed models under two primary load cases:
Key Applied Loads
- Self-Weight: Automatically calculated based on cell volume (2,210 kg/m³) and gravitational acceleration.
- Vertical Mechanical Loads (): Applied to the top rim of the electrolytic cell, simulating approximately 20,000 kg of suspended anodes, cathodes, busbars, and handling equipment.
- Hydrostatic Pressure (): Internally distributed pressure acting on cell sidewalls and bottom, factoring in the electrolyte density ().
- Seismic Loads (): Horizontal forces resulting from earthquake acceleration (). This includes dynamic liquid sloshing forces (compliant with API 650 standards) and unilateral electrode sliding impact
Evaluated Load Cases
- Load Case 1 (L.C.1 – Static Operating): HP+L (Hydrostatic Pressure + Vertical Mechanical Loads)
- Load Case 2 (L.C.2 – Seismic Operating): HP+L+S (Hydrostatic Pressure + Vertical Loads + Superimposed Seismic Forces)
4. FEA Results & Safety Factor Analysis
The FEA software calculations yielded highly favorable stress and displacement profiles for both Intermediate and End electrolytic cells across all loading conditions:
Stress & Safety Factor Summary Table
| Cell Configuration | Load Case | Max Equivalent Stress (MPa) | Material Strength Limit (MPa) | Calculated Safety Factor | Status |
|---|---|---|---|---|---|
| Intermediate Cell | L.C.1 (HP + L) | 8.8 MPa | 23.9 MPa | 2.4 | SAFE |
| Intermediate Cell | L.C.2 (HP + L + S) | 9.6 MPa | 23.9 MPa | 2.2 | SAFE |
| End Cell | L.C.1 (HP + L) | 8.2 MPa | 23.9 MPa | 2.4 | SAFE |
| End Cell | L.C.2 (HP + L + S) | 9.4 MPa | 23.9 MPa | 2.2 | SAFE |
Key Takeaways from the Analysis
- Maximum Stress Concentration: As expected, peak stresses occur under seismic conditions (9.6 MPa max for intermediate cells; 9.4 MPa for end cells) near the bottom support legs and lower corners.
- High Safety Margins: Under all operating conditions, maximum calculated stresses remain well below the ultimate material bending limit (23.9 MPa), yielding robust Safety Factors between 2.2 and 2.4.
- Minimal Deflection: Maximum lateral displacement under static full-load conditions is capped at < 1.85 mm, preventing long-term wall bowing, electrolyte leakage, or electrode misalignments.
5. Conclusion & Engineering Value
Through Finite Element Analysis, PRS validates that our Vinyl Ester Resin Concrete Monolithically-Cast Electrolytic Cells exceed standard operational and structural demands.
Whether subjected to heavy daily electrode harvesting cycles or extreme seismic events, our cell design ensures:
- Zero Leakage Risk: Monolithic casting combined with structural rigidity prevents stress cracking.
- Extended Service Life: High safety margins ensure long-term stability in high-temperature, highly corrosive acid bath environments.
- Turnkey Tankhouse Integration: Fully aligned with modern automated electrode handling cranes and high-density cell house designs.
Partner with PRS for Your Tankhouse Project
Looking for reliable, FEA-validated polymer concrete electrolytic cells or full electrorefining / electrowinning equipment packages? Contact the PRS engineering team today to discuss custom layout, sizing, and structural designs tailored to your refinery’s exact feed rate and site requirements.
