Powder blender speed

Pulverize the seeds in a clean blender until they are a fine powder. Put this powder into a beaker, add 1 liter of petroleum ether to every 900 to 1000 g of powdered seeds, stopper the beaker to prevent evaporation and let set for 3 days. Filter off the petroleum ether and let evaporate to make sure no amides were extracted (there should not be much, if any) from the ether. Add 1 liter of methanol (dry is best) and let soak for 4 days with vigorous shaking, now and then. Filter off the methanol and evaporate it under vacuo (vacuum speeds the process). In the meantime, add 500 ml of fresh methanol to the powder and extract it again for 3 or 4 days. 

Sample Preparation Transfer about 1 g of sample, previously reduced to a fine powder in a high-speed blender and accurately weighed, into a 10-mL volumetric flask, dilute to volume with chloroform, and shake for 5 min to extract the tert-butyl-p-benzoquinone. Filter through a Millipore filter (UHWP01300), or equivalent, before use. 

For semi-solid and emulsified dressings, transfer a sample to a larger vessel, mix for ca. 2 min. until homogeneous and without delay, remove a portion for analysis. Blend separable dressings with 0.20 g of egg albumen powder as emulsifier per 100 g of sample in a high-speed blender. Mix thoroughly immediately prior to removing an aliquot for analysis. Correct analytical results for added emulsifier (include appropriate quantity of emulsifier in the blank determination). 

PVC bulk polymerizations are two-slage processes in which a very porous PVC seed particle is produced in a vessel provided with very high speed agitation. The wet polymer powder from this stage is fed to horizontal autoclaves in which the polymerization is finished. Reaction heal is removed by cooling the helical ribbon blender-type agitators as well as the vessel jacket. 

Attrition Bar - A bar parallel to the rotation axis of a V-shaped blender which can be operated at different speeds. Various attrition bar designs are available which subject the powder being mixed to different shear rates. Also see V-Shaped Blender. 

Many manufacturers provide such multi-purpose mixers and examples include tumbler mixers with a high speed impactor, ribbon blenders with chopper blades and fluidized beds with impactor blades. It will be noticed that the combination is usually one of providing a gentle bulk powder circulation and the option of a high energy input. This allows for the overall bulk mixing of powders and if necessary the ability to break down persistent cohesive powder structures. 

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