[ASAD MALIK]

I know basic equation for Arc furnace trafo cal Q= m C . delta T
Can anybody explain what the major consideration for Arc furnace trafo calculation is?

I know basic equation for Arc furnace trafo cal Q= m C . delta T
Can anybody explain what the major consideration for Arc furnace trafo calculation is?

Topic

[Hamid]

The electric circuit specifics are determined first of all by the specifics of the arcs themselves. For simplicity sake, let us discuss first the processes which occur in a direct current (DC) arc; similar processes take place in high-power AC arcs. DC arc column between a graphitized electrode (cathode) and either scrap lumps or a furnace bath, is high-temperature plasma consisting of neutral molecules and atoms of various gases and vapors present in the furnace freeboard, as well as of electrically charged particles, i.e., of electrons and ions. Current transfer in the arc is conducted mainly by electrons emitted from the heated cathode. According to various estimates, in high-power furnaces, the temperatures in the arc column range within 6000

[ASAD]

Dear Hamid , I would like to estimate the power requirement , Please suggest : The available data from vender is : – consumption of hot metal : 0.75 – Consumption of DRI : 0.705 – Steel Scrap : 0.045 – Tapping weight (proposed) : 112.8 T per heat – Average electrical power reqd. : 47.6 MW (say 50 MW) (@ 280 KWH/T) – Power on time: : 27 Min. – Blowing time : 31 Min. – Tap to Tap time : 40 Min. (Considering both the vessels) – Nos. of Heats : 36 per day – Productivity based on 320 days/yr. (320 days x 36 heats x 112.8 T/heat) : Approx. 1.3 MTPY On this given information I calculate the power as below : – Tapping weight (proposed) : 112.8 T per heat Energy units required per T : @280 KWH/T Total Energy units required for 1 Heat : 112.8 x 280 = 31584 KWH Power on time: : 27 Min. = 0.45 H – In order produce 112.8 T in 27 min Amount of power required : 31584 /0.45 = Approx 70 MW Please recheck and confirm the conflic in power estimation i.e 70 MW instead of 50 MW ….. Thnx & Regards ASAD

[Hamid]

I think your calculation is very simple and suitable for electrical consumption estimation not for equipments sizing. As mentioned above the Steel arc furnace transformers operate under very severe conditions with regard to frequent over currents and overvoltages generated by short-circuits in the furnace and the operation of the HV circuit breaker (

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