Method and furnace installation for heat treating metal strip
AssigneeAndritz Technology and Asset Management GmbH
InventorsPierre-Jerome Borrel, Eric Blake
Life of this patent
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Abstract
A method for heat-treating a metal strip, where the metal strip is pre-heated continuously in a pre-heating zone with the aid of hot gas and subsequently undergoes further heat treatment in a directly fired furnace in a reducing and/or oxidizing atmosphere. The metal strip is pre-heated in the pre-heating zone with hot inert gas and further heated with an electric heating system before entering the directly fired furnace. A furnace plant for implementing the process and a related heat recovery system are also disclosed.
Claims17
A method for treating a metal strip (1), comprising:
- (a) pre-heating the metal strip (1) with a hot inert gas (6) in a pre-heating zone (3) to reach a pre-heated metal strip;
- (b) further heating the pre-heated metal strip after step (a) in a directly fired furnace (8) in one or more of a reducing atmosphere and an oxidizing atmosphere, the directly fired furnace (8) generating exhaust gases (11), wherein
- the metal strip (1) is further heated by an electric heating system (5) after step (a) of pre-heating with inert gas (6) and before entering the directly heated furnace (8) in step (b), and
- heat in the exhaust gases (11) from the directly fired furnace (8) is used to pre-heat the inert gas (6) for use within the pre-heating zone (3).
A method of treating a metal strip (1), comprising:
- (i) conveying the metal strip (1) to a pre-heating zone (3) within which the metal strip (1) is pre-heated to above 200° C. with a hot inert gas (6), thereby forming a pre-heated metal strip;
- (ii) conveying the pre-heated metal strip through an electric heating system (5) positioned downstream of pre-heating zone (3) for further heat treatment in either an inert gas atmosphere or a reducing atmosphere of an inert gas with hydrogen to more than approximately 350° C., thereby forming an electrically heated metal strip;
- and
- (iii) feeding the electrically heated metal strip through a directly fired furnace (8) positioned downstream of the electric heating system (5) for treatment in one or more of a reducing atmosphere and an oxidizing atmosphere, the directly fired furnace (8) generating exhaust gases (11), wherein
- heat in the exhaust gases (11) from the directly fired furnace (8) is used to pre-heat the inert gas (6) for use in the pre-heating zone (3).
Dependencies are inferred from the claim text.