Siebtechnik Tema manufactures centrifuges and solid-liquid-separation (SLS) process lines. Solid-liquid-separation is amongst the few most significant process unit operations. Centrifuges are used in chemical and food industry, mining and refining of mineral resources – such as fertilizer production, as well as in recycling and ZLD applications. Specific examples could be the separation of lactose, lithium salts, potash, monomer or nitroglycerin, to name just a few.

The presentation starts out with locating SLS within typical up-and downsteam process environments. Brief information is provided on mechanical SLS principles. Material properties, separation behaviour as well as equipment selection will be presented for exemplary applications.

After this section, which intends to create a common understanding for SLS, focus is turned on process intensification matters. Three examples will show how SLS with centrifuges can make a major contribution to operational excellence:

An example will be used to explain how replacing batch equipment with continuous centrifuges can achieve major benefits for the SLS operation and the overall process. The underlying application is demanding and characterized by slow separation behavior and numerous target values – a typical case for batch equipment. It is explained step by step how a suitable type of continuously operating centrifuge could be found for this separation via pilot tests.

In a second example attention is put on innovative process measurement equipment. A measuring technique is presented, which is capable to determine solids concentration within the feed or residual moisture in the solids discharge online. The uses of this technology are diverse. In the simplest case, measured parameters may be visualized in the process control system, thus enabling a more precise monitoring of current process status. Because these measurements are usually highly accurate, it is possible to use them to control parts of the process also:

A continuously measured value for the solids moisture can as an example be used to control a downstream dryer and to minimize the heating energy required to operate the dryer. A final example shows how the performance of centrifuges can be improved by adding simple static aggregates. More specifically, it will be discussed how the novel ScreenCyclone apparatus can be used very effectively to pretreat suspensions with small solid concentrations and thereby improve the performance of centrifuges.