The aim of optimising the operating behaviour of surface filtration is to maximise the filtration time for dust separation. This is achieved by a slow increase in pressure drop during filtration and a low residual pressure drop after regeneration. These parameters can be specifically influenced by raw gas conditioning. The effect is improved energy efficiency and longevity of the filter system.

A positive influence on the operating behaviour is possible, for example, by increasing the cohesion in the cake layer for improved regeneration. The influence of gas humidity on cohesion and regeneration is known from the literature. However, the complexity of the influence of gas humidity on particle bindings and regeneration only allows targeted influencing to a limited extent. Reinforced bindings between the particles in the cake layer with increasing humidity can be considered favourable. A concomitant increase in the adhesion of the cake layer to the filter medium, on the other hand, is to be categorised as disadvantageous. The concept presented here utilises the deliquescence and efflorescence properties of salt particles to increase cohesion without necessarily increasing adhesion.

As part of the study, the influence of hygroscopic salt particles in the dust cake on the operating behaviour of surface filters was analysed using a filter test rig in accordance with VDI 3926-1. The test rig allows each filter medium to be subjected to a defined mass concentration of a dispersible powder. Furthermore, it is possible to additionally filter airborn dry salt particles and to influence the raw gas humidity by modifying the test rig.

The aim of the investigation is to determine whether the operating behaviour of surface filters is actually improved over a longer process duration when this conditioning concept is used. Based on screening and standard tests carried out, evidence was provided of a significant improvement in cake detachment due to favourable process conditions. In addition to determining ...