RSiC-walls were tested in the heat exchanger with different porosities, pore sizes and basic structures, including solid material and a channelled structure. The channelled walls, cut as slices from diesel particulate filters, appear appropriate due to their small wall thickness and high open porosity of 45 %. Additionally, they provide a cleaning option against clogging by applying pressure from the channels. However, wall cracks were detected after short operation time, which are attributed to the pressure forces on the walls coinciding with strains of the clamping. The solid walls with porosity of 25 % disposed of excellent mechanical strength at the cost of extreme pressure drop and were not used for this reason.

In view of the project deadline further experimental work was focussed on the heat transfer analysis. To realize principle operation the ceramic walls were replaced by temperature resistant steel screens with thermal strength up to 1300 °C.