Several test proved that the best flame for treatment of plastic materials is an oxiding flame, that is a flame where free oxygen is present in small quantity (0,5 -3 %). The simplest system to get such flame is the pre-mixer arrangement, like in a car carburator. Once you find the right balance between air and gas the problem has always been how to maintain this ratio over time.
Today the generator designed and realized by EsseCi, to generate combustible mixture (gas/air) necessary for feeding the burner, it is made from a gas supply pipe and a fan that sucks air from the environment, pushing it inside a venturi. In the venturi is the mixing between air and gas. The formed mixture, controlled in composition and quantity, is sent to the burner Esseci on Treatment Station. The flow of gas that is necessary to obtain an established ratio and quantity of gas/air mixture for flame treatment is regulated by means of the special GOG device and the GCV1 valve, driven by the Jonoflame J combustion analyzer through the TIC1 temperature regulator. The Jonoflame Analyser is composed of a combustion chamber where a small part of the gaseous mixture, directed to the burner, feeds a burner nozzle. To ensure proper operation, the mixture pressure sent to the nozzle must be controlled.
This system it enables the control, in real time, of mixture composition used, expressing this in terms of a temperature. This combustion temperature is in fact calculated on the basis of the air/gas mixture ratio; the higher is the combustion temperature and the richer in gas is the mixture. Mixtures that contain an excess of air (gas lean mixtures) produce flames in the Jonoflame trans- parent violet in colour, while gas rich mixtures generate flames in the Jonoflame that tend to a greenish colour and that appear surrounded by mist all around themselves.