To obtain the best thermal and metallic yields, furnaces must have well-adapted heating equipment.
For this, Dross Engineering has developed its own burners using gas as fuel and air or oxygen or both as combustive.
3 models :
• 500 kW.
• 1000/1500 kW.
• 2000/3000 kW.
Why use the hybrid burner (air + O2 + gas)
Furnaces for metallurgy are heated with gas or oil
Its combustion requires "oxidizing" air or, more precisely, oxygen in sufficient quantity to allow the hydrogen and carbon of the gas to oxidize ("burn") completely.
By oxidizing, hydrogen forms water vapor (H₂O) while carbon forms carbon dioxide, this famous CO2 which contributes to the greenhouse effect.
To completely burn a volume of methane, it must be given two volumes of oxygen and the smoke must consist of one volume of CO2 and two volumes of water vapor.
Unfortunately, nature does not provide us with pure oxygen but a mixture of nitrogen and oxygen : “the air we breathe. "
It contains around 78% nitrogen (N2), 21% oxygen (O2) and 1% so-called "rare" gas, the main one being argon (Ar).
In industrial practice, things are generally simplified by considering that the air is made of 79% nitrogen and 21% oxygen.
It is therefore important to realize that to supply a volume of oxygen to a fuel (our pure methane for example), we take with it 79/21 = 3.76 volumes of nitrogen.
However, this nitrogen does not participate in combustion (except the formation of a few ppm of nitrogen oxides : "NOx") and passes through the furnace, cooling it in the process !
To maintain the desired temperature, we must therefore agree to burn more fuel than would be necessary if we operate with air rather than oxygen.
The use of oxygen reduces fuel consumption, but oxygen has two faults :
1 / its price in certain countries
2 / the high price of the equipment
Hence the interest in using a very old system (oxygen doped burner) which we call hybrid
This burner has a warmer flame temperature + 200 ° C
10% lower gas consumption
Reduced oxygen consumption, example for a 1000 kW burner : 40 m3 of oxygen
The price has a very slight gain of 10%
This Hybrid burner is recommended for products that require high temperatures such as lead recycling because the reduction of oxides and sulfates is done at more than 1000°C
This burner on the other hand, is not recommended for recycling aluminium or zinc except to produce oxides
Since 2019, all our TRF furnaces have been delivered with hybrid burners of our design.