Mixing and loading

In the planetary ball mill, the precursor powders with molar ratio of 1.67 Ca/P were loaded and mixed in stainless steel vials and ball as a milling medium. Powder to ball mass ratio was 1/6 and the milling time was taken to 15 hours with three different rotation or milling speeds 170 rpm (Ml), 270 rpm (M2) and 370 rpm (M3). 

The prevacuum technique, as its name implies, eliminates air by creating a vacuum. This procedure faciUtates steam penetration and permits more rapid steam penetration. Consequendy this results in shorter cycle times. Prevacuum cycles employ either a vacuum pump/steam (or air) ejector combination to reduce air residuals in the chamber or rely on the pulse-vacuum technique of alternating steam injection and evacuation until the air residuals have been removed. Pulse-vacuum techniques are generally more economical vacuum pumps or vacuum-pump—condenser combinations may be employed. The vacuum pumps used in these systems are water-seal or water-ring types, because of the problems created by mixing oil and steam. Prevacuum cycles are used for fabric loads and wrapped or unwrapped instmments (see Vacuum technology). 

The oxychlorination reaction is very exothermic and the catalyst is very active, which makes it necessary to mix the catalyst with an inert diluent to avoid overheating in a fixed-bed reactor. A low surface area, spherically- or ring-shaped alumina or chemical porcelain body can be used as a diluent with the ring-shaped catalyst. The density of the inert material should be similar to the catalyst to avoid segregation during loading, and the size should be slightly different to allow separation of the inert material from the spent catalyst. 

Plastic strain localization and mixing due to void collapse in porous materials works in the same way, with perhaps an even greater degree of actual mixing due to jetting, and other extreme conditions that can occur at internal free surfaces in shock-loaded solids. 

Variable flow An assembly within which the primary airflow rate is modulated and mixed with air induced from the surroundings by means of a noncontinuous running fan that provides a variable flow in response to thermal loads (also known as parallel type). 

PLX. A liq expl developed at PicArsn (Picatinny Liquid Explosive) during WWII for use in minefield clearing devices, to be loaded by pumping. It consisted of Nitromethane 95 and ethylene-diamine 5%, which were stored and transported separately, and mixed just prior to use... 

---