Patent GB-1041831-A (GB)
Title: Gas-fluidizing container-emptying cap
IPC: B65D88/72
Filed: 1963-03-22
Abstract: 1,041,831. Fluidizing apparatus. GRANUFLOW EQUIPMENT Ltd. March 22, 1963 [March 23, 1962], No. 11512/63. Heading B8A. A pneumatic device for emptying granular materials from a container 1 comprises a cap means attached thereto and having a gas permeable mat 5, 6 adjacent the container opening and forming a chamber 3 with the plastic or non-corrodible metal pan 2 of the cap, a material outlet duct 7 for communication with the interior of the container and disposed centrally in the mat 5, 6, an outlet pipe 22 connected to the duct 7 and a fluidizing gas supply pipe 4 connected with the pan 2 for delivery of gas into the chamber 3. The gas permeable mat which is dished towards the opening 8 of the central duct 7 comprises a perforated plate 5 supporting a porous mat 6 formed from cellular polyurethane or bonded rubber particles. A baffle plate may be spaced above the opening 8 to prevent material being packed thereinto. The rim 10 of the pan 2 is shaped to receive the lip of the container wall, whereupon the two are secured together by means of a clamping band. Upon clamping, the container is inverted and clamped in a clamping stand, Fig. 1 (not shown). The container 1 is then emptied by supplying the fluidizing gas to the chamber 3 under the control of a valve in the gas pipe 4 and the discharge of fluidized material through the duct 7 is controlled by a butterfly valve 24 in the duct. The passage of the material through the duct 7 and pipe 22 may be assisted by means of a further controlled supply of gas downstream of the valve 24. In a modified cap, Fig. 6, the porous pad 5<SP>1</SP>, 6<SP>1</SP> is planar and slopes down to the outlet duct 7<SP>1</SP> during the discharge operation, thus forming a tapering chamber 3<SP>1</SP>. A baffle 9<SP>1</SP> is provided at the discharge opening 8<SP>1</SP> and may be adjustable. If the cap is fitted to a container of relatively larger diameter, Fig. 7 (not shown), the portion of the container adjacent the cap is formed like a hopper to ensure complete discharge of the material. In the embodiment of Fig. 8 (not shown), a plurality of caps are secured to a corresponding number of hopper sections of an elongated container which if stationary is provided with a gate or iris valve at the base of each hopper to allow for removal of the cap. The container may be filled through an opening in its top. In a further embodiment, Fig. 9, the cap is attached to a container of relatively larger diameter and with a substantially flat base. In order to effect complete emptying of this container an internal flexible dump wall 36 is provided in the lower portion of the container and is secured at its top edge to the container wall by means of a clamping band 37 and at its bottom edge to the rim of the cap. The wall 36 which may or may not be pervious to gas is deflected from the contour of the container to the position shown by means of gas supplied through the pipe 38. A hoop-type rollable container inverting frame, Fig. 10 (not shown), comprises two curved rocker members incorporating a fixed base-plate and a hinged top plate, between which the container is supported. In the embodiment shown in Fig. 13, a housing 43 is mounted within a circular frame comprising channel sectioned rings 44 having cross-bars 45 and mounted on driven rollers 46. The openended granular material container is placed into the housing 43 through a side opening 50 having a door. A grating 51 spaced from the upper end of the housing which incorporates the pneumatic discharge cap, supports the container upon invertion of the housing 43 and allows the material to pass through it to the cap. A flexible dump wall 53 similar to that already described is also employed here. In the embodiment of Fig. 17, the container has a flexible wall 55 of heavy rubber restrained by annular reinforcing bands 56 and longitudinal flexible ties 57. The fluidizing cap 2 is disposed in a central recess in the bottom of the container and is surrounded by a flexible dump wall 58 supplied with pressurized gas through a pipe 59. The container is filled with granular material blown in through a pipe 60. A gas escape pipe 61 is provided with a filter sleeve 62.