Crossflow impact device

A method for inactivation of insects in a pourable feedstuff or foodstuff product without significantly altering a grain size distribution of the product, wherein said method includes the following step:

• circumferential feeding of the product to be treated to a drum which rotates about a rotational axis and is provided with a plurality of first type blade elements, the plurality of first type blade elements extend approximately parallel to the rotational axis, have an impact surface and are arranged between two end parts of the drum, and
• further providing the drum with a plurality of second type blade elements, which extend approximately parallel to the rotational axis, have a blade face and are arranged between the end parts of the drum, and the blade face of the second type blade elements is inclined between 15 and 75 with reference to the radius of the drum, said circumferential feeding being in a substantially radial direction with respect to the rotational axis of the drum;
• and
• circumferentially removing the product, treated by the drum, at a circumferential location which is spaced from the circumferential feeding of the product to be treated.

An impact device for inactivation of insects in a pourable feedstuff or foodstuff product, said impact device having a housing which comprises respectively at least one inlet opening and one outlet opening for the product to be treated, and a drum which is arranged in the housing so as to be rotatable about a rotational axis,

• wherein a plurality of first type blade elements, which extend approximately parallel to the rotational axis and have an impact surface, are arranged between two end parts of the drum, and
• the drum is surrounded in part circumferentially by a wall of the housing and the at least one net opening and the at least one outlet opening are realized in the wall;
• a plurality of second type blade elements, which extend approximately parallel to the rotational axis, are arranged between the end parts of the drum;
• and
• the blade face of the second type blade elements is inclined between 15° and 75° with reference to a radius of the drum.