Abstract: The invention consists of a method and apparatus for estimating screened pulp yield using water uptake rate of a sample of screened pulp chips. A dried chip sample is placed in a wire basket and totally immersed in water. A balance records the rate of water uptake over a period of about 35 seconds. This is preferably entered directly into a computer to give an output closely predicting the yield of screened pulp.

Abstract: A bar screen system comprising two sets of interleaved bars. In each set, the height of the individual bars is staggered so that every third bar is higher than the other bars, which are the same height. The bars are driven such that the bars in one set are approximately 180.degree. behind the other set in their respective predetermined paths of movement, resulting in a tipping and agitation action which tends to present the wood chips loaded at a high rate onto the bar screen in their thickness dimension to the slots between adjacent bars.

Abstract: A bar screen apparatus (10) having inner and outer frame assemblies (14, 16), with each frame assembly including a plurality of thin, blade-like bar elements (44). Each frame assembly (14, 16) further includes means for maintaining the blade-like bar elements under tension (58, 76). The inner and outer frame assemblies are driven by a drive system which includes a drive motor (97), a first drive shaft (121) at the infeed end of the apparatus, a second drive shaft (128) at the discharge end of the apparatus and a connecting assembly (126) for connecting the two drive shafts. Certain eccentric cams (114, 116, 118 and 120) are mounted on the first drive shaft (121) and are connected to the inner and outer frame assemblies (14, 16), while other eccentric cams (140, 142, 144 and 146) are mounted on the second drive shaft (128) and are connected to the inner and outer frame assemblies (14, 16), with the bar elements in the inner frame assembly being driven approximately 180.degree.

Abstract: The system includes a variable speed motor (13) which controls the operation of a disk screen (14) which is part of a gyratory screen/disk screening system for wood chips and the like. Wood chips are fed at a variable rate to a storage bin (34), which includes a level sensor (36). The level sensor (36) controls the operation of a star feeder (42) to maintain the level of providing a varying amount of input material to the upstream end of the gyratory screen (12). The speed of the motor (46) driving the star feeder valve (42) is used to develop a control signal for the disk screen motor (13), to ensure a uniform flow rate off the disk screen.

Abstract: A bar screen (10) for sizing wood chips which includes a plurality of parallel bars (12--12) supported at their respective ends (14, 16) in such a manner and driven in such a manner that each bar moves both longitudinally and vertically. Two alternating sets of bars (12--12) are included, one set being 180.degree. removed in position relative to the other set. The speed and movement of the bars (12--12) is such that the wood chips are tipped up to a vertical orientation and supplied with such a momentum that the chips break contact with the bars and encounter a slot between adjacent bars in their thickness dimension.

Abstract: The present invention is a sample splitter used to divide a larger sample of particulate material into representative smaller portions. The device uses a fixed conical sample splitter oriented with it apex upwards. Resting on this and translatable upwards is a sample receiving hopper. The hopper has open top and bottom ends. When receiving a sample to be divided, the bottom of the hopper rests on the splitter cone to form a sample retaining seal. When the hopper is raised, the sample falls by gravity around the splitter cone. An appropriately sized sample receiver located below the splitter cone receives the desired fraction. A generally cylindrical skirt is coaxially located below the splitter cone. The sample receiver is preferably a sector shaped drawer entering the skirt from the side.

Abstract: The invention is apparatus which can automatically make a screen analysis of a granular material. The heart of the apparatus is a polygonal drum having graded screens on each of the faces except one. This open face serves as a door for introducing a sample into the interior of the drum and for discharging any material larger than the largest screen. A gear motor and crank arrangement serves to longitudinally shake the drum and agitate the sample. A second gear motor indexes the drum from screen to screen after a predetermined shaking time. Each screen fraction is accumulated on an electronic scale with weights being determined by differential weighing. The gear motors are timed by a microprocessor which also receives screen friction weight inputs and calculates a screen analysis.