The process
Milk powder, coffee and flavour spray dryers use filtered, heated supply air and an exhaust fan after cyclones and a bag filter. Hygienic construction, stainless steel, and a wheel that can be washed down.
The gas at the fan
Exhaust from a spray dryer carries fine product that is hygroscopic and sticks to any surface below dew point. A blade form that sheds deposit, insulation on the casing and easy access for cleaning.
Selection for this duty
| Construction | Axial fans in weatherproof cowls, or supply and exhaust units with filters as the air quality requires |
| Density at the fan | At about 100°C the gas density is close to 0.95 kg/m³, 79% 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. |
A packaged unit with fan, filters, cooling or heating coil and mixing box that conditions and delivers supply air. Pre, fine and HEPA filters as the air quality requires. Client-stated blade types for the AHU in general: Backward curved and forward curved.
Industries
Other fans in food and dairy spray dryers
AHU in other processes
Pharmaceutical Clean RoomsAutomotive Paint ShopsNuclear Facility VentilationHospitals and LaboratoriesData Centres and Equipment RoomsSpinning MillsPharmaceutical Coating and Granulation
Information needed to select or quote
- Gas volume and temperature. Actual flow at the inlet, normal and upset temperature, moisture.
- Dust or pollutant. Inlet loading, particle size distribution, whether it is abrasive, sticky, hygroscopic or combustible; for gases, the species and concentration.
- Required outlet. The emission limit or clean gas concentration the unit must meet.
- Site. Available space and height, material of construction preferences, and how the collected material is to be discharged.