2026-10-31
A 300 MW coal-fired thermal power generation facility located in South Sumatra, Indonesia, operates a continuous condensate water loop with a total recirculating flow rate of 850 m³/h. Condensed steam from the main steam turbine is collected in the hotwell and pumped through a primary condensate filtration unit before passing into condensate polishing mixed-bed ion exchange polishers and low-pressure feedwater heaters.
During boiler start-up, load adjustments, and steady-state thermal cycling, the condensate water picks up fine suspended magnetite ($Fe_3O_4$), hematite ($Fe_2O_3$) scale flakes, silica dust, and trace brass erosion products from steam piping and condenser tubes. Total suspended solids (TSS) during thermal load swings typically surge from a baseline of 2 mg/L up to 45 mg/L.
The facility originally operated legacy 2.5-inch outer diameter (OD) melt-blown depth filter elements housed in a massive multi-cartridge pressure vessel holding 120 elements. The legacy elements suffered from rapid surface cake compaction during load surges, causing differential pressure ($\Delta P$) spikes from 0.05 MPa to over 0.28 MPa within hours. This restricted condensate return flow, forced pump throttling, and destabilized boiler drum water levels. The plant engineering manager contracted LEFILTER to deploy a high-flow cartridge system specifically designed to stabilize flow velocity under high solids loading.
Flow Rate Fluctuations & Boiler Drum Instability: Sudden differential pressure spikes across the legacy 2.5" cartridges reduced condensate pump delivery by up to 30% (dropping flow from 850 m³/h to below 600 m³/h). This threatened steam drum water inventory and forced operators to lower turbine power output.
High Mechanical Media Deformation: Standard melt-blown filter cartridges lacked structural inner core support and pleated surface geometry. Under high differential pressure, the filter pores collapsed, causing channeling bypass and releasing captured iron scale back into the polished condensate stream.
Exhaustive Maintenance Changeout Times: Replacing 120 legacy 40-inch standard cartridges required a 4-man maintenance crew over 4.5 hours to unbolt vessel covers, loosen alignment caps, and manually extract spent elements, causing long filtration downtime.
High Media Inventory & Disposal Volume: Consuming over 1,400 standard 40-inch melt-blown cartridges quarterly created severe warehouse storage bottlenecks and high hazardous waste disposal fees.
LEFILTER’s power engineering division redesigned the condensate primary filtration skid, replacing the multi-cartridge vessel with a compact LEFILTER HF-Series High-Flow Filter Housing equipped with 60-inch large-diameter pleated filter elements.
High Surface Area Pleated Media Geometry: Each LEFILTER 60-inch element provides over 9.5 m² of effective filtration surface area. The rigid thermally-bonded polypropylene pleat structure resists pleat crowding and fluid channeling under heavy particulate loads.
High-Flow Capacity (Up to 120 m³/h per Element): The 6.7-inch (170 mm) large-diameter design allows single-element flow rates up to 120 m³/h, allowing seven 60-inch cartridges to handle the entire 850 m³/h condensate volume within a compact vessel shell.
Flow Stabilization Structural Core: The elements feature a high-strength inner polypropylene cage and outer protective net rated for high differential pressure ($\Delta P > 0.34\text{ MPa}$), maintaining structural pore stability even during violent boiler startup thermal surges.
Quick-Opening Vessel Design: The vertical 316L stainless steel pressure vessel was equipped with a swing-bolt quick-opening davit cover and ergonomic cartridge insertion guides, simplifying element replacement.
Turnkey Execution & Delivery: LEFILTER manufactured the complete vessel skid, conducted 1.6 MPa hydrostatic pressure testing, shipped the unit directly to Sumatra, and deployed field engineers to supervise piping tie-ins and startup flow balancing.


Following 14 months of continuous commercial operation at the Sumatran power plant, the LEFILTER High-Flow filtration skid achieved stellar performance metrics:
Uncompromised Flow Rate Stability: Condensate supply flow remained completely stable at a continuous 850 m³/h ($\pm 1.2\%$) across all operating conditions, eliminating turbine load cutbacks and boiler drum water level fluctuations.
Differential Pressure Control: Baseline clean differential pressure dropped from 0.05 MPa to 0.012 MPa, while terminal service life was extended to over 110 days per cartridge set before reaching the 0.15 MPa changeout threshold.
95% Reduction in Changeout Labor: Replacing the 7 high-flow cartridges takes a 2-man crew just 20 minutes, compared to 4.5 hours for the legacy 120-element assembly, reducing maintenance labor by over 92%.
Suspended Iron Scale Removal: Maintained a consistent 99.4% removal rate of particulate magnetite and rust $> 5\,\mu\text{m}$, stabilizing feed stream turbidity below 0.15 NTU.
Project Financial Payback: Lower media consumption, zero turbine load drop incidents, and reduced maintenance labor fully amortized the capital cost of the LEFILTER system within 4.8 months of startup.