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Q: melting scrap steel ( Answered 3 out of 5 stars,   2 Comments )
Subject: melting scrap steel
Category: Business and Money
Asked by: papiton-ga
List Price: $25.00
Posted: 11 Jul 2003 13:55 PDT
Expires: 10 Aug 2003 13:55 PDT
Question ID: 227950
1. Am seeking an energy consumption comparison for steel melting
furnaces between an Electric Arc Furnace and an Induction Furnace.

2. The relevant data would be in kilowatt hours of electric power per
ton of steel melted.  (KWH/ton)
Subject: Re: melting scrap steel
Answered By: pafalafa-ga on 11 Jul 2003 15:23 PDT
Rated:3 out of 5 stars
Hello papiton-ga,

I've actually had the opportunity to visit a few steel-making plants
in the U.S., and it's hard to think of any human activity quite as
impressively hot.

I think you'll find the following document has exactly what you need
in terms of comparing energy profiles:

Draft Reference Document on
Best Available Techniques in the Smitheries and Foundries Industry
Draft November 2002

It is a European Union report, and is available in PDF format at: brefs/PDFs/smitheries.pdf

I've extracted the relevant information below, but you really might
want to look at the full report for a discussion of furnace
efficiencies and comparisions.


Section 3.2.3 on Electric Arc Furnaces:   

500 - 600 kWh of electricity is used to melt and raise one tonne of
steel to its casting temperature. Furnaces are normally rated at 500
kVA per tonne, giving a melting time of about 1.5 hours.

Section 3.2.4 on Induction Furnaces:   

Surveys of foundries show that consumptions of 520 - 800 kWh/tonne
metal charge are common, the variation being due to individual melting
practice such as the rate at which the pouring line will accept the
molten metal and whether furnace lids are used effectively. Attention
to energy saving measures should allow figures of 550 - 650 kWh/tonne
metal charge to be achieved.


I trust this answers your question fully, but if anything is unclear
-- or if you need additional information -- just let me know by
posting a Request for Clarification, and I'll be happy to assist you


Request for Answer Clarification by papiton-ga on 12 Jul 2003 11:54 PDT
Sorry I did not answer sooner - my server was down and just reopened.

What I had hoped was a more specific comparison.  For example, the arc
furnance has more emissions and requires a larger bag house.  Charging
can require two or more steps while the scrap is melted that would
cause heat loss.

It takes so many KWH to melt steel, regardless of the energy source. 
It would be the total system KWH consumption and efficiency of melting
(percentage of scrap to steel) that would impact the economics of one
system or the other.

My research does not reveal such information, hence the posted


Clarification of Answer by pafalafa-ga on 12 Jul 2003 14:17 PDT
Hello again Papiton,

I noticed you are a first-time user of Google Answers, and it's a
shame that your experience here so far has not been to your
satisfaction.  I hope I can correct that as we go forward.

For future reference, it is best not to rate an answer until the
process is finished.  The researchers here are generally more than
happy to continue working on a question until a customer receives a
"five star" response.  But rating a question prematurely can sometimes
put an end to the process of improving upon an initial answer.

In order to best assist you in your work, I would like to ask a
question:  have you been able to look at the document I mentioned in
my original answer?  Here is the link again (which didn't seem to
reproduce correctly the first time):

This document has a very comprehensive comparison of EAF and IF
performance across a wide variety of parameters.  From what I
understand of your question, it seems to have all the information you

Are you looking for me to summarize this information for you?  

Or is their some sort of information you need that isn't contained in
the document?  If the latter, let me know what it is, and perhaps I
can find it elsewhere.

Please let me know what it is you need at this point, so that I can
continue working on this, and give you the "five star" answer that you


Request for Answer Clarification by papiton-ga on 12 Jul 2003 16:12 PDT
Thanks for the timely response - I will be more judicious and
restrained on my rating in the future :).

Also, the link did come through this time and I was able to skim the
document.  I have not read in detail but will study to see if an
answer to my question is contained in the paper.


Clarification of Answer by pafalafa-ga on 12 Jul 2003 16:16 PDT
Good...glad you got it.

Let me know if I can help.

papiton-ga rated this answer:3 out of 5 stars

Subject: Re: melting scrap steel
From: neilzero-ga on 12 Jul 2003 09:15 PDT
Assuming the heating time for the arc furnace is also 1.5 hours, the
induction furnace uses slightly less electricity. There should be
little difference, but my guess is the induction furnace is more
reliable. The answer is in the details such as thermal insulation and
the furnace lids.  Neil
Subject: Re: melting scrap steel
From: neilzero-ga on 12 Jul 2003 09:35 PDT
Sorry, I did not read the pafilfa summary carefully enough. The arc
furnace appears to be more thrifty with electricity, perhaps because
the induction coils need to be cooled. Perhaps the induction furnace
takes more than 1.5 hours to reach proper temperature. Longer would
meen more heat loss and less production from the same capacity
furnace. The induction furnace is likely a bit larger on the outside
and may have some features that are desirable as it is newer
technology. Neil

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