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The PRH cutter moves through a linear path on the belt at speed twice conveyor speed (typically in range of 80-160 inches per second, or 0.2-0.4 m. per second)
to extract all material from a designated section on the belt into sample. Actual cutter path through the load on the conveyor belt is in the form of a parallelogram with an angle of 30 deg. The cutter
attitude angle relative to the conveyor is adjusted to the 30 deg. path to minimize possible loss of sample during cutter travel through the material load on the belt.
Cutter rotational travel is mechanically braked at a discharge position just beyond the conveyor belt edge. Sample in the cutter then discharges into
a collection chute directing sample into a collection container or to the next stage of processing. Skirts installed on the conveyor belt on either side of the cutter path prevent scattered solids from flowing
material entering the sample chute.
The PRH sample cutter travelling at high speed through material carried on the conveyor enables efficient sampling of moist materials having tendency for
adhering to surfaces. Cutter discharge is enhanced by momentum with brake action at completion of the sampling cycle. Advantages of the PRH mechanisms also includes simplified installation requirements and
relative lower quantity of sample volume per extraction by comparison to conveyor discharge trajectory sampling.
An electric gear motor drive is connected to the cutter shaft through a self-aligning grid coupling held by two pillow block bearings. Adjustment of
cutter radius length to the belt arc and cutter angle to traversing path in moving through material burden on the belt is made at a shaft holding block. The cutter is provided with adjustable plastic plate of durable
quality (polyurethane or equivalent) to safely minimize clearance between the cutter radial arc path and the belt surface while avoiding contact with the belt. Cutter volume is approximately equal to the cumulative
sample volume.
Cutter opening is recommended as equal to a multiple of three times nominal particle top size, and cutter radial arc length as approximately equal to the width
of material load on the conveyor belt. A scraper-brush device is provided to recover any remaining and residual fines left on the belt surface into the sample.
A timer-starter control unit Model PB-200 series is available for operation of the single sampler, or alternatively operation can be carried out with a
centralized control system.
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