Plug Fan for Ceramic Tunnel and Roller Kilns

The process

Tile, sanitaryware and tableware kilns run on gas with combustion air blowers, a kiln exhaust fan on the preheat zone, and hot air fans that recover cooling zone heat for the dryers. The exhaust carries fluorine and sulphur compounds from the body and glaze.

The gas at the fan

Kiln exhaust with light dust and fluorine or sulphur compounds from the body and glaze. Hot, mildly corrosive; stainless steel or coated construction on the wetted parts.

Selection for this duty

Blade form	Backward inclined or backward curved; the residual dust does not justify a radial wheel
Material of construction	Stainless steel on all wetted parts, grade to suit the gas analysis
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.

A centrifugal impeller without a scroll, plugged through the wall of an oven, dryer or air handling unit so it recirculates the air inside the chamber. Belt driven or direct driven from outside the hot zone. Client-stated blade types for the Plug Fan in general: Backward curved.

Industries

Other fans in ceramic tunnel and roller kilns

Plug Fan in other processes

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.