A curtain apparatus having a hood with a top plate in which a plurality of slots are positioned approximately parallel to each other. A fixed woven mesh metal curtain is mounted within one slot so that the fixed woven mesh metal curtain remains in a fixed position with respect to the top plate, during operation of a descaler. A moveable woven mesh metal curtain is mounted within another slot so that during operation of the descaler, the moveable woven mesh metal curtain can translate along a longitudinal axis of the slot. The moveable woven mesh metal curtain is detachably engaged with a curtain bracket that is secured to a moveable guide arm.