GB190320771A - Method of and Apparatus for Extracting Pearls from Oysters and other Mollusks - Google Patents

Abstract

20,771. Dixon, G. G. Sept. 26. Gems.-Relates to a process of, and apparatus for, extracting pearls from oysters and other mulluscs. The oysters are conveyed to the apparatus in a number of retainers or hoppers A, running on rails a<1>, and are left in the retainers a sufficient time to decay, partially or wholly. Such rotting may be assisted by heat, or by the introduction of chemicals or organisms. The hoppers are then discharged into one or more disintegrators B, which consist of revolving perforated drums, supplied with a current of water from the main F. While being charged, the disintegrators are held against rotation by bolts operated by handlevers, which may also work the sliding doors b. The disintegrators are connected to the source of power by clutches b<4> operated by levers b<3>. The disintegrated matter or saraku containing the pearls passes into the casings b<6>, and thence by conduits b<7> to the classifiers C. Each disintegrator has a movable cap b<8>, operated by the hand-lever b<10>, and can be tilted, to discharge the shells &c., by means of the screw b<12>. The classifiers C consist of a series of rotary screens c, c<1>, c<2>, c<3>, mounted on the inclined shaft c<4>, and preferably having meshes of successively increasing coarseness. They are surrounded by a casing c<3>, and may have internal lifters for showering their contents. They are supplied with a current of water. Sand and small pearls of no value pass through the screen c and enter the gully c<7> leading to waste. From the other screens the sorted matter passes by conduits c<8> to the desiccators D, which consist of a number of canvas, woven wire, or other band conveyers or travelling aprons, heated by steam pipes, or they may consist of steam-jacketed screw conveyers. The dried matter passes to the separators E, consisting of a number of inclined overlapping trays e, each of which communicates with the succeeding one by an aperture e<4>. The rapidly-rolling pearls tend to overshoot the apertures and collect in the hoods e<6> hinged to the trays. The irregularlyshaped and more slowly-moving matter falls through the apertures. The lower parts e<5>, Fig. 7, of the trays slide on arms e<7>, for the purpose of adjusting the sizes of the apertures e<4>. The trays may have covers. Instead of the arrangement shown in Fig. 1, each disintegrator may have a stationary hopper, communicating by means of a flexible or telescopic shoot. AÙrial ropeways may be used for conveying the oysters. Perforated trays, to drain off part of the moisture, may be interposed between the classifiers C and desiccators D, and may have a reciprocating or equivalent motion.