Patent GB-779479-A (GB)
Title: Means for conveying pulpy or plastic materials
IPC: B65G53/12
Filed: 1956-02-16
Abstract: 779,479. Pneumatic conveyers. SCHWING, F. W. Feb. 16, 1956 [Feb. 17, 1955; May 23, 1955; Jan. 19, 1956], No. 4834/56. Class 78 (1). In pneumatic apparatus for discharging pulpy or plastic materials, e.g. mortar and concrete, from a batch pressure feeder 21, Fig. 1, through an outlet 3 and conveying them through a pipe-line, the feeder, which is of circular cross-section, has a deflector 4 arranged concentrically within it. Air is supplied in known manner to the top and lower part of the feeder through pipes 5, 6, Fig. 2. Air is supplied also to the part where the upper cylindrical portion joins the conical bottom part through an encircling duct 7 provided with a number of equidistantly spaced orifices. Traps 8 prevent the entrance of concrete into the air inlets and a baffle-plate is arranged horizontally below the outlet from the pipe 1. The airtight bell 10, which closes the feeder head, is provided with a circular duct 11 through orifices in which compressed air is discharged into the gap between the bell and feeder to remove any adhering concrete. Air is discharged at the junction between the feeder and outlet from a pipe 21, Fig. 6, which passes through the deflector 4. The outlet of the pipe 21 is covered by a perforated cap 31 which directs the air stream into the form of a fan. This cap may be replaced by an elastic plate, e.g. of rubber, provided with slots, e.g. of T-section, which are forced apart by the issuing air. In a modification the cap is a cup-shaped body which is formed by drawing the centre of a flat plate into the mouth of the pipe. Half sections of two constructions of the feeder are shown in Fig. 10. In each construction a sleeve 35 of elastic material, preferably rubber, is provided within the feeder. This sleeve takes the shape 36 when the feeder is loaded, but when air is introduced into the space between the sleeve and the wall and also inside the sleeve, the sleeve tends to bulge as indicated by the dotted lines 37, 38 and any concrete adhering thereto is thrown into the outlet. In the construction shown in the right half of the Figure, the wall 2<SP>11</SP> is vertical. In each construction adhering concrete is removed from the bell by jets of air issuing from apertures 40 in communication with an annular supply duct formed between the hopper and the wall 39. The collar 42 round the edge of the inlet is splayed and as the bell 10 rises, it scrapes off any concrete adhering to it. In the construction shown in Fig. 11 axial and tangential air jets are injected into the feeder by nozzles 44 supplied with compressed air by a pipe ring 45. The conveying pipe consists wholly or in part of lengths provided with helical flattened surfaces or flutings to cause rotation of the material. The material is discharged from the pipe into a receiver through the enlarged end section 27, Figs. 18, 19, where it is divided into two streams by a wedge-shaped body 29. The occluded air escapes through the space 28 and the material is discharged through the outlet 30. In a modification, Fig. 20, the conveyer pipe 46 discharges into a jacket 48. The lower half of the pipe is undercut at 47 to allow early escape of air towards the vent 52. The speed of the material is retarded by a rubber floor 49 and by rubber baffle-plates 50.