6 with a planar supporting surface and through bores analogous to the through bores 5 of the plates 1 2 and on the outer side a planar sealing strip 7 with analogous through bores a further crosshead 8 may be placed on the sealing plate the positionally fixed fastening of the individual elements takes place as depicted by means of screw connections 9 the outer regions of the sealing strip 7 are l shaped parallel to the path of the sealing gap 4 so that a flexible sealing element here a silicone tube 10 can be additionally placed between the sealing strip 7 and the plates 1 2 as a result of the screw connections 9 adequate sealing of the separating gap 4 against vapor or gases is consequently obtained if need be however a further sealing plate 11 may be provided as depicted between the separating gap 4 and the sealing strip 7 or the top crosshead 6 positional compensation perpendicular to the plane of the separating gap 4 is possible in the case of a sealing joint according to fig2 two casing parts 20 21 of a multilevel dryer are connected to each other in a sealed manner forming a separating gap 4.