Fig. 26.
Revolving Strainer and Knotter.—The revolving strainer, which was invented by the late senior partner in the firm of Messrs. G. and W. Bertram (now Bertrams, Limited), has since been extensively adopted, and the present firm have introduced a patent knotter in conjunction with the apparatus, the complete arrangement of which is shown in Fig. 26. The standard size for these revolving strainers is 7 feet long by 18⅜ inches wide on each side of the four surfaces. The vats are of cast iron, and the apparatus is supplied with driving gear, bellows, regulating boxes and spouts, as necessary. The firm also supply these strainers with White's patent discs, and Annandale and Watson's arrangement. A A are two revolving strainers, as applied to the paper-machine, showing gearing for strainers and bellows. B is the patent knotter as used for two strainers. C is the counter-shaft overhead. D D is the back shaft of the machine, and E E the wire of the paper-machine.
Fig. 27.
Self-cleansing Strainer.—The same firm also introduced this form of strainer, an illustration of which is given in Fig. 27. The action of the strainer is described as follows:—
The pulp flows on to the strainer at A, and passes away through the pipes B B. At C is a valve for the discharge of waste pulp. The strainer plates have an inclination of about 1 inch in the direction of their length, and in those which are nearest to A, where the pulp enters, the slits are wider, the knots being pushed forward by the energy of the flow. The vacuum pumps, D D, are worked from the shaft E. The tubes F F are for supplying water to the plates, by which the coarser particles of the pulp are pushed forward, and the slits are thus kept clean. The strainer will pass from 18 to 20 tons of the finest paper per week.
Fig. 28.
Fig. 29.