The invention discloses a
scrap preheater of an electric-arc furnace step disturbance
culvert. The
scrap preheater comprises a heat-exchanging
culvert, the low side of the heat-exchanging
culvert is connected with a furnace, the high side of the heat-exchanging culvert is respectively connected with a
smoke-collecting and dust-removing
pipe and a feed sealing device, the heat-exchanging culvert comprises a material- conveying groove and a
smoke guide cover, the material-conveying groove is used for conveying steel
scrap materials to the electric-arc furnace, the
smoke guide cover is covered on the material- conveying groove and is used for guiding smoke, the heat-exchanging culvert is provided with at least one cross-section abrupt change structure in the height-extending direction, and the cross-section abrupt change structure is used for disturbing the steel scrap
material flow state and the
smoke flow state. The invention further discloses a preheating method of the electric-arc furnace step disturbance culvert, and the steel scrap materials can be added to the material-conveying groove by the feed sealing device; the steel scrap
material flow state is disturbed under the combined action of the cross-section abrupt change structure on the heat-exchanging culvert and horizontal vibration, so that the steel scrap materials have air permeability in a certain area; and the
smoke flow state can be disturbed in the smoke guide cover, so that the smoke and the steel scrap materials can be subjected to heat exchanging fully.