Pleated Filter Cartridge Application Case in Chemical Filtration
23th Oct, 2023, A large fine chemical manufacturer in Taiyuan City, Shanxi Province, encountered frequent blockages in pipelines and processing equipment due to impurities present in reaction liquids, solvent recovery streams, and intermediates. The chemical media involved were complex, including acids, weak alkaline solutions, alcohols, organic solvents, and trace metal ions. To ensure long-term stable operation, the customer sought filtration solutions with strong chemical resistance, stable filtration accuracy, and long operating cycles.
Key issues included:
- Rising differential pressure
- Insufficient flow
- Sediment buildup
- Unstable temperature control in downstream equipment such as distillation columns, heat exchangers, and metering pumps
Original Filtration Problems:
- Traditional metal mesh filters had limited filtration accuracy (50–80 μm)
- Differential pressure increased rapidly
- Required shutdown every 3–4 days for cleaning
- Caused unstable production and reduced throughput
On-site sampling and laboratory analysis revealed the following:
- Chemical Media Characteristics
- Corrosive and viscous mixture of organic chemicals
- Particle size distribution ranged from 1–50 μm
- Media temperature fluctuated between 60–90°C, pressure between 0.6–1.2 MPa
- High demand for filter mechanical strength and chemical compatibility
Filtration Solution:
Introduced 316L stainless steel filter housings with enhanced corrosion resistance, upgraded to multi-cartridge configurations to increase filtration area, integrated differential pressure monitoring, adopted duplex filter housings to enable online cartridge replacement without shutdown.
Filter Cartridge Selection:
A. PTFE Membrane Pleated Filter (1–3 μm)
Suitable for organic solvents, weak acids/bases, alcohols
Excellent chemical resistance
Smooth membrane surface prevents clogging
Can be backwashed for extended service life
B. Fiberglass Depth Filter (5–10 μm)
Serves as primary filtration
Large dirt-holding capacity
Effectively captures colloids, gels, flocs, and oversize particles
C. Polypropylene (PP) Filter (Final Polishing)
Ensures product clarity
Low cost and long replacement cycle
Stage Filtration Design
Final process adopted:
Coarse Filtration (Fiberglass) → Fine Filtration (PTFE) → Final Polishing (PP)
Online Switching
A duplex filter system was added to enable uninterrupted production during filter cartridge replacement.
Real-time Monitoring
Continuous tracking of: differential pressure filtration cycle
Temperature fluctuations
This allowed optimization of maintenance intervals and performance models.
Performance Evaluation (After 4 Months of Operation)
Significant Filtration Improvement:
| Item | Before | After |
| Filtration accuracy: | 50–80 μm | 1 μm |
| Solid content: | 100–200 mg/L | 5–10 mg/L |
| Filter cycle: | 3–4 days | 2–3 weeks |
Equipment Stability:
| Distillation column fouling reduced by 70% |
| Heat exchanger performance improved by 15–20% |
| Metering pump wear decreased by 60% |
Economic Benefits:
| Annual savings in maintenance and downtime: USD 60,000–90,000 |
| Product yield improved by 2–3% |
| Filter replacement cycle extended from 4 days to 20–25 days |
