Candle Filter vs Bag Filter: Why CakeFil Wins on Total Cost in High-Duty Applications

What a bag filter actually costs in a high-duty chemical application

In a chemical or food processing application with moderate suspended solids loading, filter bags are replaced every one to three weeks. At $50–$200 per bag with four to eight housings on a typical process circuit, the annual bag cost is $5,000–$40,000. Add the labour cost of bag changes — 30 to 60 minutes per housing at $40–$60 per hour shop rate — and annual labour is $2,500–$12,000. Add disposal cost for bags saturated with process chemicals (regulated industrial waste at $0.50–$1.50 per pound), and the downtime cost of each change event, and a "simple" bag filter installation costs $15,000–$80,000 per year in operating cost for a moderate-duty application.

CakeFil operating cost for an equivalent application: filter cloth replacement every 6–24 months (cloth life depends on the solids filtered, but LENZING's 80% better pore cleaning per backwash directly extends this interval). Annual cloth cost: $2,000–$8,000. Labour: minimal — CakeFil operates fully automatically. Disposal: the cake discharges as controlled slurry or dry solid directly from the automated system. Total annual operating cost: $3,000–$12,000. Three-year comparison on a moderate-duty application: bag filter $45,000–$240,000; CakeFil $25,000–$60,000 including capital amortisation. CakeFil pays back in 18–36 months and delivers permanently lower operating cost thereafter.

Three applications where CakeFil is the only viable technology

1. Sub-micron particle separation at high flow rate. Bag filters are limited to approximately 1 micron nominal at very low flow rates per housing. CakeFil achieves below 1 micron via filter cake formation at flows above 1,000 m³/h in a single vessel. There is no bag filter configuration that delivers this combination.
2. Dry cake discharge for downstream processing. Bag filters produce wet, contaminated bags that go directly to waste. CakeFil's dry discharge mode produces a filter cake with controlled, low moisture content suitable for washing, further drying, or direct recycling — essential for catalyst recovery, mineral concentrate dewatering, and pharmaceutical solid isolation where the cake itself has economic value.
3. Fully automated continuous operation. Bag filters require manual intervention every 1–3 weeks in moderate-duty applications. In hazardous chemical environments, each intervention is a safety event requiring PPE, containment, and waste handling. CakeFil operates for months without manual intervention — the automated backwash cycle maintains filtration performance continuously within a closed system.