Grooved plate method

The angle of internal friction can be measured indirectly, in shear cells for example, or directly, by the grooved plate method. There... 

Fig. 19. Grooved plate method of measuring internal friction.

The angle of internal friction can be measured directly by the "grooved plate" method. The base of the Jenike shear cell is replaced by a metal plate in which a number of saw-toothed grooves are cut (Figure 2.15). These... 

The grooved plate method for measuring the angle of internal friction. 

Solenoid magnetic separators are designed for batch-type, cyclic, and continuous operation. Devices which can use matrices of expanded metal, grooved plates, steel balls, or filamentaiy metals have been designed. Continuous separators with capacities to 600 t/h for iron ores (similar to the Brazilian hematite) are commercially available (Sala International Inc.). Selection of the method of operation is apphcation-dependent, being based on variables such as temperature, pressure, volume of magnetics in the feed, etc. 

Measuring surface crack depth is performed by calibration samples made of the same material like the object being tested. Calibration samples are the plates having narrow grooves like slits of various depth 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm and made by electric erosion method. The samples have dimensions 50 mm X 150 mm x 6 mm and 25 mmx 150 mm x 6 mm and are made of magnetic... 

If the thermocouple wires are located in a hole or groove in a metal tube or plate, the fin effect will be remedied, but the heat flow pattern through the solid will be altered. The correct surface temperature can be computed by the relaxation method. This corrected method has been used for boiling studies (S2), but many workers have made no correction for embedded wires. 

The bipolar plate design is illustrated in Fig. 47. It consists of a cross-flow arrangement where the gas-tight separation is achieved by dense ceramic or metallic plates with grooves for air and fuel supply to the appropriate electrodes. A porous cathode, a dense and thin electrolyte and a porous anode form a composite flat layer placed at the top of the interconnected grooves. The deposition of the porous electrodes can be achieved by mass production methods. Moreover, the bipolar plate configuration technology makes it possible to check for defaults, independently and prior to assembly of the interconnection plate and the anode-electrolyte-cathode structure. 

Another method of grid manufacture is via mechanical treatment of a strip or slab of lead alloy. The traditional procedures (Plant6-type plate) have been either to cut grooves into a thick lead plate, thereby increasing its surface area, or to crimp and roll up lead strips into rosettes which are inserted into round holes in a cast plate. The resultant plates are formed electrolytically into positives in the classic Plante and Manchester designs (Fig. 23.13). 

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