Level measurement in the bleaching tower with VEGAPULS 68 radar sensor

A number of different measuring principles are implemented for level measurement in the bleaching tower. But high pulp density, material cones, build-up or high temperatures create difficult measuring conditions and bring ultrasonic, hydrostatic, guided microwave and even radar instruments close to their limits.

Ordinary radar sensors are designed for liquids. The high density bleached material in the upper part of the bleaching tower, however, is very dry and, like bulk solids in general, has poor reflective properties.

The VEGAPULS 68 radar sensor in K-Band technology was especially designed for level measurement of bulk solids. Through improved hard and software, the dynamics were increased by 30 dB. VEGAPULS 68 can thus detect echoes that are a thousand times smaller than those radar sensors for liquids can normally detect. Reliable measuring results are delivered even during filling. This is especially important for continuously operating bleaching towers. The energy requirement is so low that VEGAPULS 68 can be operated as a two-wire instrument.

These properties make VEGAPULS 68 the ideal solution for difficult level measuring applications in the paper industry. With its newly developed horn antenna (with a diameter of only 95 mm and flanges from DN 50) VEGAPULS 68 is well suited for retrofitting or reequipping silos used for chips, starch, ash and sludge.

VEGAPULS 68 is integrated in VEGA's sensor concept plics. Housing versions in plastic, aluminium or stainless steel belong to the broad selection of options. Even the electronics leave nothing to be desired: the 4 ... 20 mA model is available in two or four-wire technology, the fieldbus model is available in Profibus PA or Foundation Fieldbus version.