Abstract: The operation of a vacuum-conveying hopper feeder is controlled using pneumatic logic circuitry including a leak sensor relay providing improved control accuracy and with a sensor orifice which becomes occluded by a spring-loaded plunger when the feeder body is filled to a predetermined weight. The leak sensor relay connects through a pneumatic logic NOT element to an aspirator or pump control valve and releases the vacuum allowing the contents of the body to be dumped. Time delay elements can be included between the relay, NOT element, and control valve so as to continue the filling for a predetermined interval following occlusion of the sensor orifice and to continue the dumping for a period following unblocking of the orifice.

Abstract: In a method of loading the hold of a suction dredger vessel, in which a sension of sand and water is pumped into the hold during loading which is carried out in a first stage and a subsequent second stage for avoiding that a siphon effect is not possible and that the last quantity of water cannot be replaced by a sand-water mixture, the effluent means are kept, after the suspension level in the hold has reached the external water level, under the action of a suction pump for lowering the suspension level to below the external water level.

Abstract: A stationary or portable conveying system for conveying particulate dry products is disclosed. The conveying apparatus is 100% air operated, with few moving parts, and requires no electric controls, no rotary valves and no timers. The apparatus disclosed includes a storage vessel provided with product intake and discharge openings. The valving associated with the storage vessel automatically operates alternately to admit product to the storage vessel during an intake cycle and, when the storage vessel is full, to automatically shift to a discharge cycle to unload the product from the storage vessel. A valve mounted to the vessel near the top detects the level of product in the vessel. The valve includes a generally cylindrical body having a central bore communicating with a plurality of ports. A longitudinally displaceable valve stem is mounted in the bore and is spring biased to project beyond one end of the valve body.

Abstract: A method and apparatus for improving the flow of a powder from a source, such as a large hopper, to the intake of a conventional machine wherein such powder is compressed into tablets. Devices are arranged along the route of powder flow so as to restrict, decelerate and depressurize such powder flow and thereby prevent its surging, compaction and/or bridging. These devices are also arranged to maintain the powder in a loose condition of uniform density.In the preferred embodiments, said devices include most or all of a return duct to the powder source, an upper filter to atmosphere, an upper baffle against which the powder is directed, a restriction, an elongated powder tube through which the powder flows, a lower baffle and a final pressure relief filter to atmosphere. Mechanism in the tableting machine receives the thusly prepared powder and forms it into tablets much faster than previously possible.

Abstract: A system and apparatus for forming webs from textile fibers entrained in an air stream in a conduit with a perforated plate dividing the interior of a housing into first and second chambers so that the entrained fibers fall to the bottom of the first chamber and the air passes through the plate while a portion of the plate is oscillated. The passage between the conduit and first chamber increases in cross-section from conduit to first chamber to reduce the velocity of the air and entrained particles.