Air curtain design

In the following we apply the dynamic method of air curtain design (see Fig. 7.92). The basic dependency is illustrated for a one-sided air curtain that is supplied at angle a and developed on the plane surface XOY. Since the jet of the air curtain is bent by the effect of differential pressure from outside and inside (P ) the building, the jet of the air curtain flows to the opposite side of the aperture and splits into two parts. After the division, one part of the jet flows along the outer surface of the enclosure and the other one enters the room at an angle (i to the plane surface of the aperture. We isolate the... 

Air Curtain and Exhaust Off-Take Air curtain design and exhaust offtake location are very important considerations. The air curtain is applied on roof openings that are typically 2 to 3 m wide and used for crane rope access. The opening may extend over the length of the enclosure and should, therefore, be served by two sets of independently operated doors— one for tapping and one for charging. This feature minimizes the pen area when one of the two events occurs. 

The air curtain design equations are outlined in Chapter 7. The plume data for furnace charging are used in this calculation step. Note that the plume volume flow impinging on the width of the slot should be used rather than the whole plume flow. 

During melting, the air curtain should efficiently direct fume towards the exhaust off-take without allowing recirculation within the enclosure. The air curtain design should therefore also consider the fume trajectory when a lower updraft velocity from melting is experienced. 

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