Moving Bed Heat Exchanger System
Client
Major Canadian Oil Sands Producer
Location
Fort McMurray, Alberta
Capacity
12,000 kg/hr solids handling
Standards
ASME Section VIII, CSA B51
Project Overview
Designed a high-efficiency moving bed heat exchanger (MBHE) system featuring proprietary pillowed plate technology for a bitumen extraction facility. The system recovers waste heat from hot coke particles to preheat boiler feedwater, achieving 15% faster production cycles while maintaining strict ASME compliance.
Key Challenges
- Abrasive particulate flow causing wear concerns
- Thermal expansion management at 350°C operating temperature
- Maintaining air-tightness in pressurized sections
- Ensuring cleanability for coke dust accumulation
Design Highlights
1
Pillowed Plate Bank Configuration
- Staggered array of 304L stainless steel plates
- Hydraulically formed pillow geometry for structural rigidity
- 5mm gap spacing optimized for particulate flow
- Leak-tight laser welds at all penetrations
2
Material Selection
- Primary plates: 304L SS for corrosion resistance
- Wear liners: AR400 steel in high-abrasion zones
- Gaskets: Graphite-reinforced for high temperature
- Fasteners: A193 B7 studs with Inconel nuts
3
Innovative Features
- Self-cleaning plate surface treatment
- Modular cassette design for maintenance
- Differential thermal expansion accommodation
- Integrated instrumentation ports
Technical Specifications
Performance Metrics
- Heat Transfer Area: 480 m²
- Thermal Efficiency: 78% recovery
- Pressure Drop: ≤ 2.5 kPa
- Solids Throughput: 12 MT/hr
Design Parameters
- Design Pressure: 1,850 kPa
- Design Temperature: 375°C
- Corrosion Allowance: 3mm
- Design Life: 25 years
Validation Methods
- Finite Element Analysis (FEA)
- Computational Fluid Dynamics (CFD)
- ASME Appendix 26 fatigue analysis
- Prototype wear testing
Key Calculations
The plate thickness was verified using ASME Section VIII Division 1 Appendix 13 for stayed construction:
t = p√(0.25P/SC) + CA
Where:
- t = Minimum plate thickness
- p = Pitch between stay points
- P = Design pressure
- S = Allowable stress
- C = Joint efficiency factor
- CA = Corrosion allowance
Project Outcomes
15%
Reduction in energy consumption
20%
Higher throughput than conventional designs
0
Maintenance incidents in first 12 months
100%
ASME compliance verification
Notable Achievements
- Developed novel plate support system reducing deflection by 40%
- Implemented predictive wear modeling extending service life
- Reduced fabrication hours by 30% through modular design
- Achieved client's ROI target in 14 months