Improvements in or relating to paper stock distributing mechanisms

摘要

967,622. Paper-making apparatus. BELOIT CORPORATION; Aug. 8, 1963 [Oct. 8, 1962], No. 31404/63. Heading D2A. [Also in Division F2] A stock distribution mechanism for a high speed papermaking machine comprises a stock delivery slice arranged to feed a layer of stock on to a travelling forming surface, a pressure supply device for the stock, a stock conduit leading from the supply device to the slice and arranged to conduct stock therebetween under pressure, and a pressure relief valve communicating with the conduit and actuable to relieve pressure in the conduit at a predetermined pressure in excess of a normal operating pressure. The valve may be in a headbox of the pressurized air type or in a surge chamber. As shown in Fig. 4 the valve comprises a cover plate 21 normally held on seat 19 over opening 18 in the conduit by the adjustable fluid pressure in a chamber 27 formed between a supporting plate 24 and a diaphragm 22 attached to the plate 21. When the force on plate 21 due to the pulp pressure in the conduit exceeds the opposing force on plate 21 due to the pressure in chamber 27, plate 21 rises, releasing pressure in the conduit while at the same time opening valve port 51 thus releasing pressure in chamber 27 and thus causing the plate 21 to be lifted right away from opening 18. Chamber 27 supplied with air from pressure regulator 31 (Fig. 2 not shown) may have a pressure relieving valve of standard construction. The valve support plate 24 is mounted on a yoke 34, which is pivotal about pin 43 to allow access to opening 18 so that it may be used as a manhole. Swing bolt 47 clamps yoke 34 over the opening 18.