The basic idea behind the oil burner is to drip a small amount of oil onto hot plates that vaporise the oil , this hot gas then combusts inside the kiln. Several important considerations are:
1. The oil can be of any grade, sump oil from cars through to kerosene can all be used, obviously the more contaminated the oil (like sump oil for instance) the more contaminates and pollution will be caused by burning the oil. Also the oil will need to be filtered to remove any particulate.
2. The metal plates require preheating in the early stages of the firing. This can be achieved with gas burners, or even a wood fire. Once the firebox has got hot the radiant heat will keep the plates hot and the burner becomes more efficient the hotter these plates become.
3. The burners require a decent amount of air flow past them to pull the vaporising and burning oil into the kiln. This can be achieved with a tall chimney or use a forced air system by incorporating a blower into the system (this latter alternative will give a more controlled and efficient burning of the oil)
4. In addition to the dripping oil a small amount of water can also be dripped onto the hot plates, this is recommended only after you reach 1000 degrees and only a very small amount of water is need. The water acts in two ways, firstly it provides steam as a carrier of the oil vapour and also can be beneficial as a reducing agent inside the kiln.
As with all burners a trial period is needed for the potter to come to grips with the system. It can produce vast billowing clouds of smoke if too much oil is used, similarly it can choke up the firebox with clinker is badly adjusted. But when working optimally, with the correct air, water and oil ratio it will produce a clean burning flame. |