LED lighting for food production at Weyermann^® specialty malting

Lighting in high humidity conditions

Barley germinates vigorously in the Saladin box. In this box, innumerable barley grains are kept constantly moist and automatically turned. After a maximum of one week, the germinated grain – the green malt – is removed from the germination box and transported to the kiln, where the water is removed from the grain. Weyermann^® uses this kilned malt to produce malt extracts or its own roasted malt beer. The latter is renowned because it has been brewed according to the same recipe since 1902 – behind mighty brick façades that are now protected as historic monuments.

Inside these listed buildings, state-of-the-art technology works in line with the latest hygiene standards. To ensure this, the company is successively upgrading the building fabric and plant technology, for example, the chambers where germination takes place. Recently, renovated germination box 7 went into operation. With a length of almost 30 metres and a width of 6 metres, it holds about 100 tonnes of fresh grain. To ensure the germination process runs smoothly, a very specific type of micro-climate is needed along with high humidity of 100 per cent and an air temperature of 12 to 17 °C. These factors produce condensation on all of the surfaces, on the tiled walls, the stainless steel areas and even on the NORKA ZUG LED tubular luminaires that run the length of the room on the ceiling. The medium beam luminaires are activated when staff check the germination process or take samples. This happens twice a day. It was thus key that not only the box but also the narrow maintenance corridor along its long side were sufficiently illuminated. For safety reasons, 250 lux was required, and the appropriate positioning of the luminaires was calculated and optimised by simulation.

The ZUG LED tubular luminaires used in the germination box are specially designed to meet the requirements of production areas in the food industry. They comply with several protection classes, including IP69K, which allows cleaning with a high-pressure cleaner. The cylindrical cover made of fracture proof polycarbonate serves as a diffuser; the driver is safely integrated. With a rated power of 50 watts each, a luminaire produces a luminous flux of 7450 luminous flux. Due to the above-average exposure to moisture, the end caps of the luminaires have been partially mould-sealed with the connecting cables.