GB720073A - Improvements in or relating to the cleaning of sacks by suction - Google Patents

Abstract

720,073. Vacuum cleaning apparatus. BEHRMANN, O. A. L., [trading as NACHF, A. K.]. Oct. 17, 1952. [Oct. 17, 1951] No. 26170/52. Class 8 (1). An air pervious open necked flexible container e.g., a sack 5 Fig. 1 is cleaned by suction which is repeatedly connected and disconnected e.g., by a flap valve 13 in a suction duct 7 connected to the sack neck so as to cause the sack to repeatedly assume the inside out and the normal position. The sack neck is secured to a reversing socket 3 large enough to accommodate the sack in the reversed position and return is effected by gravity which may be assisted by closing a valve 15a in the discharge duct of the suction source 9 so as to provide a return of air through a duct 12, a small open aperture in the closed valve 13 and a filter chamber 8 leading to the inlet of the suction source 9. A plurality of sacks 5 may be connected in parallel to a common suction duct 7 and the valve 13 is actuated at a desired frequency and duration by a solenoid 14. Dirt from the filter chamber 8 is collected in a container 11. In a modified reversing socket 16 Fig. 2 which includes a coarse filter screen 21 the suction current traverses a controllable aperture 25 in a pivoted plate 24 which on opening the valve 13 is drawn to and held against the open end of the socket and on closing the valve 13 opens under gravity to allow return of the sack. Air inlet apertures 26 and further apertures 27, 27a controlled by an annular rotary slide valve 29 provide auxiliary suction currents impinging axially and radially against the outside of the sack as viewed in the inside out position.