Abstract: A side for a furnace used in the manufacture of silicon carbide from silicon dioxide and carbon comprises a plurality of gates which are removably affixed to the furnace or plant floor. Each gate has a base portion intended to be supported by a plant floor and a plurality of upstanding supports. Affixed to each of the upstanding supports are a series of vanes which vanes are sloped downwardly and inwardly toward the center line of the furnace. The width, configuration and vertical spacing between vertically adjacent vanes are all chosen such that the silica sand and carbon mixture cannot flow outwardly through the side of the furnace under the effects of gravity while at the same time gases produced during the reaction may flow readily outwardly through the furnace sides.