Inline NIR Installations for Powder in Ducts/Pipes and Fluid Beds

By Kenneth Rasmussen, Insatech A/S

Wide experience has been gathered with a reliable and accurate inline NIR solution for moisture, fat and protein analysis for solid materials. For homogeneous products like powders and fine granules you can achieve an accuracy down to +/- 0.1 pct by weight (1σ) against your reference (e.g. moisture). A major advantage with these NIR solutions is to provide you with a high accuracy without the need for extensive and time consuming chemometrics. The solution uses fixed filter NIR and is easily calibrated to your type of products, using your normal samples, in no time.

Installation in ducts/pipes

In ducts and vertical pipes with falling product, a “powdervision” insertion tube can be installed as shown in Figure 1. The cup is filled with product, a measurement is made through the sapphire window and the cup is then blown empty with dry instrument air. This cycle repeats itself and gives you fast updates for your process parameters to control.

Figure 1

In Figure 2 you see the solution installed at Andels-Kartoffelmelsfabrikken Sønderjylland, a potato starch factory. The NIR solution is their primary tool to control the drying process and it is therefore possible to achieve a specific water content closer to their set point and hence maximize their profit.

Figure 2


Installation in fluid beds

In fluid beds inline installation can easily be made. A sapphire flange is installed in the fluidized layer so that the product covers the sapphire window as shown in Figure 3. During drying, the product moves against the window having a self-cleaning effect. The measurement is made through the window real time and gives you a second by second moisture profile. Maribo Seed International ApS have invested in a NIR solution for two fluid beds. The installation is shown in Figure 4.

Figure 3


Figure 4

At Maribo Seed the NIR solution has given them a repeatable drying process that eliminates under- and over-drying. The energy savings from less drying is the major benefit from the NIR solution and they now dry down to a given set point without the need for frequent analysis of samples during the drying process.


Kenneth Rasmussen, M.Sc. Chem. Eng., Product Manager – Analytical

Insatech A/S

Tel.: +45 55372095