kWh Per Ton Calculation Question

As far as the difference in the calculation and energy used; have you considered the efficiency of the process, the waste heat, and the energy to operate the equipment?

The system used to melt the two different metals may be the same, and operate at only one temperature, thus the energy cost of operating the equipment would be the same. If you have a furnace that melts steel, it would definitely melt aluminum without modification, however, it would take less time.

Most workers do not want to spend allot of time doing complex calculations. The best method would be to provide a Excel spreadsheet where all they have to do is input the quantity, and the energy use would be displayed. Depending on the accuracy needed, you could print a completed table for the most common amounts.

Also a ton of aluminum will take up allot more volume then a ton of steel. The same weight of the two metals may take different quantity of processes to complete.

Er, it's kWh per ton (not kW per ton; shoot the pedant).

In calculating energy consumption, the energy loss routes need to be established and an appropriate allowance made.

401/660 ≈ 61%. Reasonable, though could do better. It's always worth looking at cost-effective ways of reducing the 660kWh/ton towards the 401kWh/ton figure. Better insulation, perhaps?

Hi all,

Thanks for the comments and answers I will make a few comments back.

Zaphod congrats, you got a good answer mark from me. It was exactly what I was looking for, namely some formula to calculate THEORETICAL energy requirement.

Techno, thanks for your comments. As I said above, i am looking for theoretical calculations first, then I will work in efficiency in the table I give to the operator. I do not know what your background is but the energy requirement for melting Steel and Aluminium is very close to 1:1. Thus it will not be faster to melt aluminium than melting steel (my opinion), if all else stays the same (furnace, energy input etc.). In my case it is not really that they do not want to make the complex calculation, it is more a case of lack of skills and knowledge. So they cannot make the calculation, I have to do it for them. But, because I did not have a plain formula, it took me a few hours to calculate what the different energy requirement would be if we change the material to be melted next. Yes, i am going to print out a table of figures and stick it to the wall, for myself I am going to build a little database with the relevant constants and then can do a quick reference calculation when I want to something different, say Iron Silicide, or Ferro manganese ....

PWSlack: I was just checking to see if you're awake ;). Off course it is kWh per ton, because it takes time. In other words it will take X kW to melt 1 ton in 1 hour. As I mentioned the theoretical values to melt aluminium and steel should be the same. Then you work on volume and temperature and furnace efficiency etc and it will be different. But again, I will keep on posting my progress and continue to study and figure things out.

Thanks for all your help guys, I cannot express how much I have learnt from being part of CR4. It is easier and more productive to post a question here and get all the comments form a host of people, than to ask the question to my colleague with his Masters degree in Metallurgy sitting 6 feet away.

Regards,

TC

I have worked in a Machine shop as a machinist and a welder.

Aluminum melts faster by volume and by temperature.

By weight it would be about the same.

Aluminum melts at a lower temperature. 660 °C

Depending on the carbon content, steel melts between 1540°C and 1400°C,