In late February 2026, the manufacturer expanded its fibreglass-reinforced plastic (FRP) centrifugal fan range to size No. 20, reaching airflow up to 50,000 m³/h for corrosive exhaust in chemical and wastewater applications.
Corrosive exhaust is one of the most misunderstood duties in ventilation, because the failure mode is silent: a metal housing thinned by acid mist does not announce itself until it cracks, and by then the extraction train is down. Fibreglass-reinforced plastic answers that threat at the molecular level, but only if the resin system matches the actual effluent, since a generic 'FRP' label says nothing about which chemical it resists. Extending a proven FRP line to larger single units is therefore a capacity answer as much as a corrosion answer, letting plants consolidate duty instead of paralleling smaller fans.
Why FRP, and Why Larger
Standard painted or galvanised steel fails quickly when the airstream carries acid mist, chloride, or wet scrubber discharge. FRP construction resists a broad range of chemicals while keeping weight manageable, which is why it is the default choice for scrubber outlets and tank-farm ventilation. The gap until now was size: many plants needed larger single-unit capacity than the range offered and had to parallel smaller fans.
Extending to No. 20 lets a single fan serve bigger ducts without splitting duty across multiple smaller units, simplifying structure, supports, and control. For a wastewater treatment plant, that can mean one corrosion-resistant unit handling a large aeration or odour-extraction zone instead of three smaller ones fighting for duct space.
Larger FRP housings also demand better laminate control. Peripheral speeds rise with size, so the new sizes use reinforced wall construction and carefully tuned resin content to keep deflection within limits that protect the impeller clearance and the structural seal.
Expanded Range at a Glance
The larger sizes follow the same backward-curved impeller logic as the smaller FRP units, with reinforced housings for the higher peripheral speeds. Representative duty points are listed below.
| Size | Max airflow | Typical static pressure | Application |
|---|---|---|---|
| No. 10 | 12,000 m³/h | 1,500 Pa | Lab exhaust |
| No. 14 | 25,000 m³/h | 2,000 Pa | Scrubber outlet |
| No. 18 | 40,000 m³/h | 2,200 Pa | Wastewater odour |
| No. 20 | 50,000 m³/h | 2,500 Pa | Chemical plant |
Resin choice matters as much as size. Vinyl ester laminates suit strong acid streams, while modified epoxy systems handle broader chemical mixes; the correct selection depends on the specific effluent, not a generic "FRP" label. A wrong resin fails invisibly as the laminate softens and the housing loses stiffness.
Temperature is the other limit. FRP has a working ceiling well below steel, so the peak exhaust temperature, including upset conditions, must stay within the laminate's rated range with margin. Specifiers who ignore a hot excursion risk a housing that deforms and jams the impeller.
Selection Checklist for Corrosive Duty
Engineers specifying FRP fans should work through these points before releasing an order:
- Identify the chemical: Match resin (vinyl ester vs epoxy) to the actual stream, including trace contaminants that may be more aggressive than the bulk fluid.
- Confirm temperature: FRP has a working-temperature ceiling; verify against peak exhaust heat, not the average, and add margin for upsets.
- Size on duty point: Select at the required pressure and flow, not the catalogue maximum, so the unit runs near its efficient zone.
- Plan access: Corrosive duty needs frequent inspection; specify externally accessible drains and a hatch so internal checks do not require cutting the housing.
- Motor isolation: Keep the motor out of the airstream where possible to extend life and simplify maintenance in a hostile environment.
- Document the spec: Record resin, temperature, and chemical basis so future replacements match the original intent.
Significance for Plant Operators
Keruite has built fans for 30+ years from its 80,000 m² Dezhou base and holds CCC and ISO 9001:2015 certifications, so the larger FRP range extends proven corrosion practice to bigger single-unit duties. For operators, the practical benefit is fewer parallel fans and a simpler, more reliable corrosive-exhaust train.
Plants planning capacity increases can now specify one unit where two were previously required, cutting structural and control complexity. the company supports the selection with in-house performance testing so the quoted duty is backed by measured data rather than an estimate.
For specifiers, the discipline is to name the chemical and the peak temperature, not just the flow and pressure, because FRP has a working-temperature ceiling well below steel and a wrong resin softens invisibly over time. Vinyl ester laminates suit strong acid streams while modified epoxy handles broader mixes, and the choice should follow the plant's real discharge, including trace contaminants. The company's 30+ years of fan manufacturing, its CCC and ISO 9001:2015 certifications, and the 80,000 m² Dezhou facility together let the larger FRP range be offered with in-house performance testing that confirms the quoted duty against the actual curve.
Engineers in Dezhou respond to selection enquiries within 24 hours, and the factory ships most standard fans from its 80,000 m² site within agreed lead times.