1,017,393. Pneumatic conveyers. COAL INDUSTRY (PATENTS) Ltd. May 11, 1962 [May 18, 1961], No. 18155/61. Heading B8A. A rotary feeding valve for use in pneumatic stowing comprises a hollow cylinder 18, Fig. 3, arranged for rotation in a cylindrical housing 12 and having an aperture 22 co-operating with an aperture 13 in the wall of the housing 12 through which solid material is delivered. Conduit means 26, Fig. 1, for the introduction of conveying air is arranged axially of the hollow cylinder 18. Air is supplied intermittently through a plate valve 24, Fig. 1, oscillated through a cam mechanism which opens the valve 24 when the apertures 13, 22 are closed. The air supply may be augmented by a pneumatic accumulator. In a modification a pair of contra-rotating cylinders 50, 51, Fig. 5, is arranged below the hopper 58 the apertures 56, 57 being phased so that upper cylinder 50 receives material when sealed off from the lower cylinder 51 from which material is ejected by air directed from an axially aligned supply conduit 66.