Patent GB-190225109-A (GB)
Title: Improvements in and relating to Appliances for Elevating and Discharging or Conveying Grain and the like.
Inventor: HAVILAND JOHN
Filed: 1902-11-15
Granted: 1903-11-12
Abstract: 25,109. Haviland, J., Haviland, r. H., and Farmer, J. Nov. 15. Elevators. - Relates to the pneumatic elevators described in Specifications No. 2146, A.D. 1898, No. 4653, A.D. 1899, and No. 15,275, A.D. 1900, and comprises improvements in the dusttrapping devices and other internal fittings of the vacuum chamber. The dust-trapping chambers are fitted with discharge valves or flaps, which open automatically under excessive pressure and prevent rupture of the filtering-surfaces, and also with chambers from which the dust is enabled to flow away without interruption. Baffles, airchannels, &c. prevent the air currents from stopping the Bow of grain and thus choking the chambers, and pipes &c. are sometimes fitted to break the fall of the grain. In the water trap through which the air also passes, the tube or chamber dipping into the water is suspended like a pendulum or by a universal joint, so that the heeling of the barge or vessel in which the apparatus is placed does not allow the air to pass under the edge of the chamber and over the surface of the water, and thus carry the dust into the pumps. The pumps connected with the suction pipe H, Fig. 1, produce in the chamber A, a partial vacuum, which draws in the grain &c. through the pipe C. The ascending dust-laden air passes through the gauze or perforated-metal filtering surfaces of the chamber B, and the finer dust passes through and collects on the doors B', which are hinged on a bar b, and are supported by chains b<2> and a weight b<8> so that the dust may be discharged into the hopper A<1> by raising the weight b<8>. Hinged doors or valves, such as E, are provided to relieve the pressure on the gauze when the chamber B becomes filled with fine dust. In other arrangements, the doors B' are replaced by a single door, partly balanced, and placed horizontally or obliquely ; or a series of vertical doors may be placed round the lower end of the chamber B. The lower part of the filtering-chamber may be suspended so as to telescope into the upper part, which is fitted with relief valves ; or the lower part may be extended upwards and closed at the top, so that the upper part may be dispensed with. Flat filtering-screens, fixed or mounted in slides, may be used, their lower ends being fitted with relief valves which are also used for discharging the dust. The grain inlets and the suction pipe may be arranged so that the dust collects in the space between the filtering-chamber and the vacuum chamber, the lower part of which space is closed by oblique counterweighted valves ; or the valves may be placed horizontally so as to open upwards under excessive pressure. The filtering-screens may be hung on hinges at the top of the chamber; or they may be fitted in pairs in a vacuum chamber, the dust collecting in the spaces between them being removed by screws or vane wheels. Fig. 18 shows an arrangement of funnels R, down which the grain &c. descends slowly, the dust collecting in the space between the vacuum chamber and the filter B. Air channels Q<1> and a baffle Q<2> direct the air so as to keep clear the lower edge of the filter. Fig. 20 shows another arrangement, in which the dust passing through the filter B descends into a quiescent space in the funnel B<7>, and is thus run into the discharge valve D. In modifications of the form of apparatus shown in Fig. 18, the grain passes from the inlet at the side of the apparatus into a single large cone fitted with an adjustable door, which cone may form an extension of the filtering-chamber, as in Fig. 20. Hinged and fixed screens may be used separately or together. A rectangular dust-filtering chamber may be formed by four screens pivoted to the top of the vacuum chamber, or a single filtering-screen placed obliquely and protected by a baffle may be used. The screen may be replaced by one having the form of an inverted cone or pyramid open at the apex. The vacuum chamber may be made without filtering- screens, in which case, the hopper at its lower end is made with air channels from which rise vertical air pipes, and the air is conducted through the water trap. In the water trap, the tube, chamber, or bell, which dips into the water, is suspended by a ball-and-socket joint, or by a universal joint consisting of two pivots at right-angles to each other, or by a single pivot.