초록 ▼

A scrap preheating system of the type employing a conveyor upon which the scrap is placed, an elongate burner hood surrounding the conveyor and burners within the hood which direct flames upon the scrap. The side walls of the burner hood include an elongate exhaust chamber and side wall ports betwee

A scrap preheating system of the type employing a conveyor upon which the scrap is placed, an elongate burner hood surrounding the conveyor and burners within the hood which direct flames upon the scrap. The side walls of the burner hood include an elongate exhaust chamber and side wall ports between the exhaust chamber and the interior of the hood. An exhaust fan induces a negative pressure under the hood through the exhaust chambers which pulls the unburned hydrocarbons from under the hood through the side wall ports into the exhaust chamber. Additionally, air is drawn upwardly between the conveyor and side walls of the hood and through the side wall ports into the exhaust chambers wherein combustion is completed and pollution reduced. The length of hood and burner array exceeds the length of scrap material on the conveyor. The conveyor is periodically jogged during the preheating cycle to slightly advance and mix the scrap and only those burners positioned above the scrap are operated as it advances. The burners are initially operated with a slightly oxidizing flame until hydrocarbons are burned from the scrap and thereafter operated with a slightly reducing flame to prevent significant oxidation of the metal.

대표청구항 ▼

In a scrap preheating system including a conveyor on which the scrap to be pReheated is positioned, enclosure means positioned over the conveyor and burner means associated with the enclosure means for directing flames upon the scrap, the improvements for eliminating unburned hydrocarbons comprising

In a scrap preheating system including a conveyor on which the scrap to be pReheated is positioned, enclosure means positioned over the conveyor and burner means associated with the enclosure means for directing flames upon the scrap, the improvements for eliminating unburned hydrocarbons comprising: an elongate exhaust chamber extending along and adjacent the enclosure means; communication means providing communication between the enclosure means and the exhaust means generally along the length thereof; air bleeding means for introducing air to the exhaust chamber generally along the length thereof; and exhaust means for inducing a negative pressure within the exhaust chamber for drawing the unburned hydrocarbons through the exhaust chamber wherein they are mixed with the air and burned.