B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
B07B1/48—Stretching devices for screens
B07B1/49—Stretching devices for screens stretching more than one screen or screen section by the same or different stretching means