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VERSION:2.0
METHOD:PUBLISH
BEGIN:VEVENT
ORGANIZER;CN='8th ECIC & 9th ICSTI 2022':MAILTO:info@ecic-icsti.com
LOCATION:Room „Danzig“
SUMMARY:Channelling in the blast furnace
DESCRIPTION:Title:	Channelling in the blast furnace

Oscar Lingiardi (1), Rob van Opbergen (2) and Maarten Geerdes(3) 
1)	Ternium, Argentina, olingiardi@gmail.com 
2)	Danieli-Corus, The Netherlands, Rob.van-Opbergen@danieli-corus.com
3)    Geerdes Advies, The Netherlands, geerdes@mgeerdes.nl

Channelling in a blast furnace is a local, preferential gas flow through an area with the lowest gas resistance. Channelling occurs frequently and has major impact in loss of chemical and physical energy of the gas.
Most of the channelling starts along the wall of the furnace. Because of the inverse conical shape of the shaft a gap is easily formed when burden descends. Channels have a self-enhancing effect: a strong gas flow blows away materials, preventing materials collapse in the channel. Therefore channels are observable from strong decrease of the gas utilization, locally high heat losses and/or stave temperatures as well as pressure taps.

Experience shows, that channels can be caused by irregular burden descent, because fast descent creates a gap between wall and burden. Irregular burden descent is caused by uneven melting of the cohesive zone. This can be caused by
-	Concentration of fines. 
-	Drainage of primary slag because of poor melting.
-	Unstable burden descent.  
Remedial actions for channelling are the following. 
-	In the very short run an operator will try to have the channels collapse by checking and operate at a lower blast volume.
-	In the long run, the occurrence of channels has to be prevented by having stable burden descent. 

The paper will show, that effects on ETA CO, stave temperatures, heat losses and pressure taps indicate the same channelling phenomenon. Remedial actions are discussed and operational examples will be given.

CLASS:PUBLIC
DTSTART:20220831T132000
DTEND:20220831T134500
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