Lightweight container by NNPB is the strictest target of every container glass producer. Falorni Tech is presenting its Flexible Glass Conditioning System to make NNPB production possible. This customer-driven solution is crucial for achieving suitable thermal homogeneity at the spout entry.
The ability to be flexible and agile is one of the key qualities for being competitive in the glass container market: glass containers have to be maximally light, as well as less expensive, and at the same time they have to withstand maximal mechanical loads, greater internal pressure, thermal shocks (pasteurization), etc. For the glass containers to be able to meet these requirements, apart from a well-designed container it is necessary to achieve also excellent glass distribution (uniform thickness of glass container wall), which can be achieved by the production procedure of NNPB (narrow neck press and blow process).
Compared with the conventional Blow-Blow process, NNPB demands more rigorous requirements of the process variables and general setup. However, it should be emphasized that despite the relevance of a cutting-edge IS machine, the key issue in NNPB production is the thermal homogeneity of the melted glass achieved in the conditioning forehearth. Only by the proper combination of technologies that involve the whole forehearth, the achievement of suitable thermal homogeneity can be possible. The Flexible Glass Conditioning System by Falorni Tech has been developed to serve this objective: before all, the glassmaker who wants to turn its production in NNPB must be sure of the performance of its glass conditioning system. And the FLEX-COND system represents the optimal combination of technologies, properly upgraded since 2010, that works for reaching the highest level of the Thermal Homogeneity Index (THI) with values beyond 98% with flint glass.
In the FLEX-COND forehearths, the channel zones superstructure is designed with a winged roof profile that creates independent and separated areas across the channel width. This means the possibility to manage separately the cooling and heating effect not only within the channel length but within every single zone (two-dimension control of heating/cooling distribution). The superstructure is then provided with a composite ducting system in which hot gases and/or cold air are managed to flow by the action of dampers and forced air. The FLEX-COND superstructure has a modular design and can be used both in distributor and forehearths. The standard design size is for channel width from 26” to 48”. Tailored and bigger dimensions can be designed as well up to 54” (tandem massive production). The geometry of the forehearth (width, length) is calculated considering the required range of pull rate, glass color, inlet conditions, and layout so that there’s normally not a straight and unique solution possible. The capacity of production required for one single forehearth can range from 30 tons/day (smallest units) up to more than 200 tons/day, for the biggest and massive production of containers.
How does FLEX-COND work
When the glass reaches the channel entrance, the mission of the forehearth itself is to carry the glass to the spout entrance at due temperature granting meantime the most homogeneous temperature in the mass.
As every operator knows, the issue is to determine the suitable energy setting along the forehearth which grants the right balance among Forced heat supply (combustion), Natural heat losses (heat losses through the walls), and Forced heat losses (cooling). Being each forehearth of invariable geometry (length, width, and zone arrangement cannot be modified during operation), the only possibility to manage the glass conditioning is to modify the combination of these three energy contributions. FLEX-COND allows managing the forehearth superstructure heating/cooling geometry with a large number of combinations that make possible the synchronized effect of the combustion and the cooling functions. The operator can “drive” the glass temperature profile by reading the 9-points grid temperatures and then adjusting, easily and without a particular setting, the forehearth zoning up to the achievement of the due performance. FLEX-COND, or Flexible Glass Conditioning, is exactly this concept: finding easily and quickly the forehearth setup within any pull range of the channel, in the function of the number of cavity and gob weight.
In each zone, the operator can decide to heat channel sides while the central section can provide “no heating” or, also, “cooling”. One of the key features of the FLEX-COND is the possibility to manage in the middle section Direct Cooling or Indirect Cooling depending on glass characteristics (color and oxidation) or temperature target. FLEX-COND forehearths can process any kind of oxidized or reduced glass (Flint, Green, Amber, Dead Leaf, etc.) without any particular setting and granting the highest level of Thermal Homogeneity Index THI.
FLEX-COND is a combination of integrated technologies
The right concept and a rigorous design path are the cornerstones of FLEX-COND, which embeds integrated solutions that contribute to the overall performance of the glass conditioning system.
The channel heating is supported by a combustion system based on Falorni Tech AQRatio (Accurate Air/Gas Ratio Control System). This system is designed to guarantee a constant and stable Air/Gas ratio at any heating range. The airflow is controlled by a servo linear flow valve which provides repeatable and exact flow value within the entire range of action. The Gas flow is controlled through a servo-mechanical actuator by which the gas flow amount is linearly proportional to the airflow at any flow range. The Air/gas ratio is kept constant during the regulation fluctuations driven by the temperature profile demand and is independent of the pressure losses in the air/gas mixture line downstream the regulation skid due to fouling in the pipe or the burners.
FLEX-COND is supported by Falorni Tech ICS (Interactive Control System) a controller based on a unique technology that supports the whole conditioning phase.
Falorni Tech’s IT Team in cooperation with the University of Pisa is developing the next version of ICS: it is conceived to generate a database of experience directly from the daily field use, as a platform to enhance efficiency by providing quick response for problem-solving, fast setting, sharing of experience. A new controller philosophy, which provides the standard control capabilities but with additional features as the systematization of logical decisions for the operator’s risk reduction, support to the operator on process status and data reading, an automatic control of a set of working parameters to reduce to the occurrence of damages/shutdowns. Falorni Tech ICS is conceived as concrete support for the operator who will be able to increase the efficiency and efficacy of the system in terms of glass quality, energy efficiency, thermal homogeneity, and boost the production output.
Last but not least is Falorni Tech COR-DIS (Cords Dissolution System). It is a stirring device designed to be used in all forehearths. It can be equipped with 2 to 4 stirrers and allows easy operation and maintenance. The system performs the dispersion by mixing the impurities present in the bottom of the forehearth and allows to set the stirrer with an inclination, boosting the bottom glass mixing.