The process
The dryer hood takes in heated air and exhausts the saturated air from the drying cylinders through heat recovery. Supply and exhaust fans handle warm, humid, fibre-laden air in stainless steel, with mist elimination on the exhaust.
The gas at the fan
Dryer hood exhaust is saturated, warm and carries fibre and chemical traces. Stainless steel construction, drainage and a design that does not trap fibre.
Selection for this duty
| Impeller | Steel or cast aluminium impeller; PAG is not used above its temperature limit |
| Form | Tube axial for low pressure; vane axial where the pressure or the downstream distribution calls for it; bifurcated where the motor must be out of hot or contaminated air |
| Density at the fan | At about 90°C the gas density is close to 0.97 kg/m³, 81% of standard air. Pressure developed and power drawn fall in the same ratio, so the selection is made at this density and the motor is checked at cold start. |
Supply, return and exhaust fans for heating, ventilation and air conditioning of plant and office space. Low pressure, so efficiency and noise govern. Client-stated blade types for the HVAC in general: Axial, backward inclined and forward curved.
Industries
Other fans in paper machine dryer sections
HVAC in other processes
Pharmaceutical Clean RoomsGas Compressor StationsTobacco Primary ProcessingFood Ovens and FryersDyeing and Finishing HousesAutomotive Paint ShopsTyre Plant Mixing and Carbon Black HandlingTyre Curing PressesGenerator and Engine RoomsCar Parks and TunnelsFactory Shed VentilationNuclear Facility VentilationCold Rolling MillsRubber and Plastics CompoundingHospitals and LaboratoriesData Centres and Equipment RoomsSpinning MillsPharmaceutical Coating and GranulationJute Mills
Services on this fan
Information needed to select or quote
- Duty point. Volume flow and static pressure at the fan inlet, with the gas density and temperature or the conditions to derive it.
- Operating conditions. Site altitude, normal operating temperature and continuous or intermittent duty.
- Gas stream. Dust loading and particle size, corrosive species, moisture, upset temperature and any tendency of the material to deposit on the impeller.
- Mechanical. Rotation viewed from the drive end, discharge orientation and motor power.