Energy consumption reduction in glass melting furnace

[deeveeyes]

We have a glass melting furnace 50 KW fed by a furnace transformer,cycloconverter and an uncontrolled rectifier, feeding the furnace at 11V DC. One of the Energy auditors measured the energy consumption at the input of furnace and found that 223 KWH energy was used to melt only around 3.4 Kgs of Glass. Accordingly they told us that system efficiency is only 1.2 %. They are suggesting us to change the transformer to a transformer having tap changer, and a full wave controlled rectifier (eliminate cycloconverter) and change the voltage from 12 V DC to 50 V DC. How do I implement this suggestion ? Is this a correct suggestion.

 

[don01]

hi
now I must admit I'm not sure about the characteristics of melting glass. But 223KWhr of power for 3.4 kg of Glass. Thems bloody expensive bottles. In Australia assume say 20c per KWhr and we get $44.60 or about $14 a kg. the Aussie dollar aint worth a lot but something doesn't sound right here.

I cannot see massive increases in efficiency from the electrical changes, unless the 50vdc has a very big affect.
also I wonder about the 55KW input to the furnace and 223KWhr used does this mean it takes 4 hours to melt 3.4 kg of glass. Did they perchance do these readings when you started a cold furnace?

Now if I'm wrong the so be it but I would ask the consultants to give you a very detailed reprt in writing and explain how they arrive at these figures and how they "justify" (for want of a better word) their recommendations. Then talk to some other specialists.

Please keep us informed I find this interesting
Regards
Don

 

[prc]

A little more detail will enable to analyse the problem further.
what is the spec of trf and rectifier currently used? How the efficiency of 1.2% arrived at?
What is the spec of trf suggested by the consultant?How did he expect to save energy in the proposed system?