Mechanical sampling cutters

Conventional design of most mechanical sampling systems for large tonnages of coal use some form of cross-stream primary cutter to divert the primary increments from the main stream of coal (Figure 2.2). A major advantage of these systems is that they sample coal from a moving stream, and most of them satisfy the principle that every particle in the entire mass has an equal opportunity to be included in the primary increments. 

The cutters in use in mechanical sampling are divided into diverter types and bucket types. Both types are used to cut a stream falling due to gravity off the end of a conveyor belt or from the discharge end of a pneumatic conveying pipe or a chute. 

Selection of hnear or radial (rotary cutter) samphng is made according to mechanical instahation factors often on a basis of flow quantity. Smaher flows can be sampled in a cost-effeciive manner by rotary cutter samplers (frequently termed vezin design samplers, see Fig. 19-4). 

A wide variety of mechanical devices are now in use and include flow-through cutters, bucket cutters, reciprocating hoppers, augers, slotted belts, fixed-position pipes, and rotating spoons. These systems typically collect the primary increments and perform at least part of the sample preparation by crushing and dividing it down to the 4- or 8-mesh stage of reduction specified (ASTM D-2013). 

First, cut a thin-film sample into a strip of thickness 0.8 mm with a diamond cutter. Mechanically grind the sample down to less than 100 pm only from one side. Clean the sample with acetone and put the ground sample on a piece of glass, the ground surface facing the glass as shown in Fig. 4.15(a). Prepare a very thin diamond particle suspension by putting diamond powder (about... 

The specimens of suitable dimensions were cut from the composite sheets by using a Diamond cutter and were subjected for analysis of tensile, compressive and flexural strength in accordance with ASTM standards on a computerized universal testing machine (Housfield H25KS). Three specimens of each sample were used for the measurement of each mechanical property at ambient laboratory conditions and average results have been reported. 

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