Quality control is an essential part of the sugar production process as manufacturers must ensure that the product complies with the customers’ specifications. Not only the look, texture and taste of the final product depends on the size distribution, but also the solubility, tendency to aggregate, agglomerate and other properties which are important for industrial processes using sugar as a raw material. Hence, care must be taken that particles are neither too small nor too big. Traditionally, the particle size determination is carried out by sieve analysis which is a rather slow, labour-intensive method and commonly subject to measurement errors such as: too much sample material, worn out (uncalibrated) sieves, wrong sieve parameters (amplitude and sieving time) or simple calculation errors. An excellent alternative for the quality control of sugar is Retsch Technology’s CAMSIZER® . CAMSIZER® measurements are fast, automated, accurate and 100% comparable with sieve analysis. With these advantages the instrument can reliably replace sieving.
With several hundred instruments in operation worldwide, the CAMSIZER® is the most successful tool for particle size and shape analysis of dry, flowable bulk products with dynamic image analysis. Due to its wide measuring range of 30 µm to 30 mm (figure 1) and the excellent comparability with sieve analysis (see figure 2), the CAMSIZER® is a powerful alternative to traditional sieving. The main areas where the CAMSIZER® is used are quality control, research and production monitoring. In combination with solutions for the partial or complete measurement automation, continuous sample analysis can also be realized cost-effectively. The patented measuring setup of the CAMSIZER® - two digital cameras as adaptive measuring unit - improves and optimizes particle analysis with digital image processing. Thus it is possible to cover the complete measuring range without any adjustments of the instrument.
In addition to the size analysis the CAMSIZER® can also analyze the shape of the particles (figure 3). This feature is essential for manufacturers who need to measure the amount of pure single crystals compared to twin/poly crystals or other aggregates and irregular shaped particles in the product.
The benefits of using the CAMSIZER® for the quality control of sugar are persuasive: • A large quantity of particles can be measured in a very short time and fully automated. This reduces the workload and guarantees reliable statistics. • The resolution and reproducibility of the CAMSIZER® measurements are much higher than those of sieve analysis. • CAMSIZER® results are 100% compatible to those of sieve analysis. • Automated sample measurement with optional AutoSampler. • Moreover, the CAMSIZER® does not require maintenance and can also be operated online (integrated in the production process) and in extremely dusty environments.
The sample is fed in from the funnel and feed channel so that all particles fall through the measurement field. During the measurement procedure the two cameras (CCD) take over different jobs: the Basic Camera (CCD-B) records large particles, the Zoom Camera (CCD-Z) detects fine particles (figure 4). The contactfree optical measurement is carried out in real time and simultaneously ascertains all the required information about particle size and shape. To make this possible in the context of an automated continuous analysis, an online version was developed which can be customized to the particular requirements. The obtained results can be presented graphically and in tabular form as size fractions, frequency distribution or cumulative distribution. In addition, the CAMSIZER® can determine the number of particles as well as the specific surface, the density and also the transparency of the sugar crystals. All parameters are ascertained with great precision and excellent reproducibility. The CAMSIZER® software also allows the presentation of daily reports, trend analyses, mean value calculations and much more. In accordance with DIN 66165, a well structured customized measurement protocol can be generated. The CAMSIZER® is also highly suitable for the size and shape analysis of beet seeds which can be measured raw and with coating finish.