Energy saving options with two-piece ovens

In the past, production line ovens were seen as a major unit that needed very little attention, with most can makers running their ovens at the same setting year after year. Today things have changed as water-based paints replace the old solvent-based ones. To eliminate the explosion hazard of solvent-based paints, ovens would typically be run with exhaust rates of 10,000nm³/h or higher to keep the air/solvent mixture below flashpoint. With water-based materials this exhaust rate can be reduced to less than 5,000nm³/h, thus halving the volume of replacement air that must be heated from ambient to oven-operating temperature. Since heating fresh air accounts for a large proportion of a drying oven’s gas consumption, this is a very substantial energy saving. It also reduces the amount of potentially contaminated air being sucked into the production area.

A second big consumer of energy are steel conveyor belts. This is because far more energy goes into heating the belt than drying the cans. An average steel belt requires a heat input of roughly 90kW (depending in width, weight and line speed). The proven synthetic conveyor belt introduced by KBA-MetalPrint (formally LTG) consumes just 3kW, which represents a substantial reduction.

KBA-MetalPrint has worked with can makers to develop a procedure for evaluating potential energy savings at the ovens. As a first step the plant completes a questionnaire which provides some basic production and oven-specific data. KBA Metal-Print then uses the data to calculate theoretical power requirements and potential energy savings. Both the calculation and evaluation are provided free of charge.If the potential energy savings revealed by these calculations are sufficiently large, then the ovens are examined and proposals submitted clarifying the savings that can be made. In most plants we are able to return an immediate energy saving simply by optimising the exhaust streams from the ovens.

Ovens can deliver huge energy savings, achieved through a range of remedies from simple adjustments to heat-recovery and air-purification systems. Depending on the production line, it is possible to achieve savings of between 500 and 1500 kW.

Why not take the first step towards turning energy costs into profits by contacting KBA-MetalPrint about this useful free service.