# Calcute Power Consumption Using Specific Heat and Latent Heat

Calculate power consumption using specific heat and latent heat for in Silver Melting Furnace
All the metals have different melting rates at certain power kW. In many cases the melting temperature of one composing metal will be boiling temperature of another composing metal in same liquid metal. In alloy steel, composing metal will have different melting rate at a different power.
In the Silver Melting furnace, theoretical required power (kW) can be calculated using specific heat and latent heat of metal. Each metal have different specific heat and latent heat.
Required power for silver melting furnace can be calculate using following theory.
Specific heat: The specific heat for a substance is defined as the number of joules (or calories) needed to change the temperature of exactly 1g of a substance by exactly 1 C.
Latent heat: The quantity of heat absorbed or released when a substance changes its physical state at constant temperature, e.g. from a solid to a liquid at its melting point, or from a liquid to a gas at its boiling point.
Specific heat of Silver: 0.237 J/g°C
Latent heat of Silver: 11 J/g
Melting temperature of Silver: 961 C
Compared to direct pouring, ladle pouring where the distance traveled from melting furnace to pouring area is more, pouring temperature is on he higher side. In such cases the power requirement is higher for the same production rate. Following temperature losses need to consider during power calculation in Silver melting furnace:
Temperature losses: 45 C furnace to ladle
20-35 C Super heating
So, 961 C + 80 C = 1041 for tapping
Mass = 1 ton = 1000 kg
= 1000 x 10^3 gm
= 1 x 10^6 gm
Required specific heat Q 1= mass x specific heat x change in temp
Q 1= 1 x 10^6 gm x 0.237 J/g C x (1041 – 25) 1041 C = Melting temperature
Q 1= 2.41 x 10^8 J 25 C = Room temperature
Required latent heat Q 2 = mass x latent heat
Q 2 = 1 x 10^6 gm x 1.05 x10^2 J/gm
Q 2 = 1.05 x 10^8 J
Total required energy to melt one ton silver = Specific heat + Latent heat
= Q 1 + Q 2
= 2.41 x 10^8 J + 1.05 x 10^8 J
= 3.19 x 10^8 j
We know, 1 J = 2.78 x 10^ -7 kWh
So, required energy in kWh = 2.78 x 10^-7 x 3.19 x 10^8 = 88.682 kWh
Using the theory above, required power can be calculated for various Induction heating, hardening and melting applications. Here, latent heat is counted for melting application only. Latent heat is only considered when metal gone be phase transfer like solid to liquid. So it will not take into account for heating and hardening application.