Method and apparatus for handling a product

A method for processing a highly viscous, pasty product, by at least one rotating shaft (3, 11) in a product space (5), wherein a drive axle (11) of the shaft (3) is mounted and sealed outside of the product space (5), in a housing composed of a plurality of parts (7, 8, 12), and the sealing is effected by at least two seals (2, 4), wherein a dynamic seal (2) follows an eccentric motion of the shaft (3) and effects dynamic sealing of the rotating shaft (3), while another seal (4), by plastic or elastic deformation, compensates an eccentric motion of the shaft (3) in relation to the housing and thus prevents an untightness between the eccentrically moving housing part (12) and a rigid housing (10),

• wherein, in the case of vacuum operation, a defined quantity of liquid, which serves as a blocking and lubricating medium for the dynamic seal (2) of the shaft (3) toward the housing part (7), is applied to the dynamic seal (2) from the outside, which liquid, apart from a residual excess, is drawn into the dynamic seal (2) by the vacuum therewithin and thereby forms an effective block and seal, whereas, in the case of pressure operation, the blocking and lubricating liquid is introduced between the dynamic seal (2) and the other seal (4).