The disclosure relates to a machine for thermal treatment of bulk material, comprising, a stationary furnace which presents a support structure, and a plurality of pallet cars traveling through the furnace, said plurality of pallet cars together defining, at a lateral side thereof, a common engagement surface which extends through the furnace, wherein a gap is defined between the support structure of the furnace and the common engagement surface, said gap having a gap length, the machine further comprising: a sealing system comprising: one or more drop bars, wherein each drop bar of the one or more drop bars includes a brush arranged on the drop bar such that the brush is configured to be in engagement with the common engagement surface such that the one or more drop bars covers the gap over at least parts of the gap length.

A transport system (34) for transporting soldering material through a soldering apparatus (10), includes a transport track (38, 40) extending in a transport direction (18). The transport track includes transport rails (42, 44, 46, 48). Coupling elements (72, 120) are provided on a transport rail (42, 44, 46). The coupling elements include guide elements (58, 60, 61) which interact with transverse rods (46) that extend in a transverse direction (54) relative to the transport direction. Each coupling element includes a guide part (100) having the respective guide element (58, 60, 61) and a fastening part (102) fastened to the respective transport rail such that the fastening part can be displaced relative to the guide part so that the distance in the transverse direction between the transport rail and the respective guide part changes.