A cellular wheel sluice embodied as a blow-through sluice is suitable for dosing secondary fuel, for example. The blow-through sluice includes a supply chute (2) in the top area and a cylindrical housing (1) which is disposed below the supply chute (2) and in which a cellular wheel (4) is arranged. The cellular wheel (4) includes radial webs (3), in the rotational area of which a blow-in hole (10) and an opposite blow-out hole (11) are provided on the side faces (26) of the housing. An injector nozzle (15) which blows the transport air into the rotating dosing chambers (5) so as to empty the same, is integrated into the housing in the area, of the blow-in hole (10). Thereby pressure differences result in the dosing chamber (5) that is to be emptied such that only small pressure loads act upon the metallically hard gap seals, which have a long useful life and allow only small quantities of leakage air, and which are arranged on the radial end areas of the cellular wheel webs (3).