Dead Void Volume

Dead volume refers to the volume within an apparatus or system that is not actively involved in the separation or transport process. In chromatography, Wikipedia defines dead volume as “volume not involved in separation, which includes spaces before and after the stationary phase as well as gaps within the medium.” Applied to filtration and conveying systems, dead volume means cavities where the medium stagnates, mixes, or is not renewed. Excessive dead volume leads to longer residence times, blurred separation profiles, increased product loss, and higher cleaning effort.
In filters, pumps, or pipelines, dead volumes mainly occur due to poorly designed housings, dead angles, pipes with large diameter changes, or excessively long connection hoses. These areas are barely flushed by the main flow, causing deposits, product retention, and in the worst case, contamination. In the food and pharmaceutical industries, minimal dead volume is essential to maintain hygienic standards. In chemical process engineering, dead volume affects reaction time and can lead to unwanted side reactions.
When designing filtration systems, we ensure dead volume is kept as low as possible. Housings for our candle filters and screen filters are flow-optimized to avoid dead spaces. Process belts and endless fabrics are precisely adapted to the dimensions of the filter housings so that no unused cavities occur. We also use hygienic quick couplings with defined transitions that do not create additional dead volume. In pilot plants, the so-called dead time t₀ is often measured – the time a medium needs to pass through the apparatus without interaction. This parameter helps determine and optimize dead volumes.
Reducing dead volume impacts not only product quality but also efficiency and sustainability. Less dead volume means less product loss, shorter rinsing times, and lower chemical consumption during cleaning. For customers in environmental technology or the food industry who require CIP-capable (Cleaning-in-Place) systems, we develop fabrics and filter housings that can be completely cleaned thanks to minimal dead space.