Integrated sensor technology within the filter plates enhances the comprehension of the filtration process in filter presses and enables its optimization. In situ measurement of cake water content, feed pressure, and diaphragm squeeze pressure provides real-time visualization and facilitates the identification of areas for improvement. Tests were conducted on a pilot filter press, involving varying filtration pressure and different diaphragm squeeze pressures for this purpose. A sensor for measuring cake water content was positioned in the head plate (Lenser i-Plate), while additional sensors on the periphery of the filter press measured feed and diaphragm squeeze pressure.

Figure 1 illustrates an example of in situ measured data of a non-optimized filtration cycle. Through the measurement of cake water content, feed pressure, and squeezing pressure, it becomes possible to precisely delineate the different stages of the filtration process. The initial increase of the cake water signal up to a peak marks the end of the filling phase. Subsequently, a decrease in cake water content and a rise in feed pressure indicate the cake build-up. At some point the maximum possible pump pressure is reached. Ideally, this...

Furthermore, the diaphragm squeeze stage is divided into two sections: a phase of continuous cake water decrease, highlighted in green, and an avoidable extension, marked in red due to lack of optimization. By eliminating the red segment, the process can be shortened significantly, reducing cycle time.

Speaking on an industrial scale, this optimization of the filter press performance will facilitate the operation of more cycles per day and enhance plant throughput. A second optimization potential resulting from in situ measurement involves obtaining additional data. Typically, measuring cake water content is only feasible after the filter press is opened. Employing an in situ sensor allows for a thorough examination of the impacts of the different process parameters at each stage of the filtration cycle.

In conclusion, it can be stated that ...