by the chemical inlets 2 as in the other embodiments the tower 22 is mounted on springs 25 and the tower is shaken by means of an eccentric cam 24 in such a way that the stock falls down continuously from one baffle plate to another and is thus repeatedly tumbled and broken up in every embodiment after being broken up the stock falls into a reaction tower 4 with a discharging device in its lower section an embodiment of a reaction tower is shown in greater detail in fig8 and 9 the reaction tower includes a tall housing which has a sloping floor 32 the reaction tower 4 may be square or round or of rectangular horizontal cross section as illustrated which may result in the saving of space the special discharge equipment described below allows the choice of shapes for tower 4 at the side of the tower housing communicating with the lower side of floor 32 the housing wall has a large rectangularly shaped outlet opening 43 passing through it the height of the outlet opening 43 can be set by vertical adjustment of a slide plate 34 the slide plate 34 runs in lateral guides 33 on the tower housing the plate 34 is adjusted for example by means of threaded spindles 35 knurled internally threaded wheels 36 are operated manually or by a motor for rotating the spindles 35 instead of the threaded spindles 35 it is also possible to use a pneumatically or hydraulically operated piston to adjust the height of.