Dust Collector Fan for Gypsum Calcining Plants

The process

Gypsum is calcined in kettles or flash calciners and the plaster moved by air slides. The calciner exhaust carries fine gypsum dust at temperature, and air slide blowers aerate the plaster on the way to the silos and packers.

The gas at the fan

Clean air at elevated temperature from a dryer, oven or cooling duty. The selection is made at the hot density, with the shaft and bearings arranged for continuous hot running.

Selection for this duty

Blade form	Backward curved or aerofoil for the best efficiency on clean gas
Material of construction	Mild steel
Drive and bearings	Direct coupled, shaft cooling disc, bearings in a pedestal outside the gas stream, allowance for thermal growth
Density at the fan	At about 250°C the gas density is close to 0.67 kg/m³, 56% 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.

The fan behind a bag filter, cyclone or multiclone on a dust extraction system. Placed on the clean side where possible so the blade can be chosen for efficiency. Client-stated blade types for the Dust Collector Fan in general: Backward inclined and radial tipped.

Industries

Other fans in gypsum calcining plants

Dust Collector Fan in other processes

Services on this fan

Information needed to select or quote

1. Duty point. Volume flow and static pressure at the fan inlet, with the gas density and temperature or the conditions to derive it.
2. Operating conditions. Site altitude, normal operating temperature and continuous or intermittent duty.
3. Gas stream. Dust loading and particle size, corrosive species, moisture, upset temperature and any tendency of the material to deposit on the impeller.
4. Mechanical. Rotation viewed from the drive end, discharge orientation and motor power.