Screw planetary

Twin shell Vibratory pehhle mill tiirretf Vertical screw planetary types Cage mill Screw feeders... 

Internal modifications. Here belong the screw modifications, as well as the devices that need to be attached to the screw, e.g., Barmag s torpedo, RAPRA s cavity transfer mixer (CTM), a multi-screw planetary unit. All three examples also require modification of the corresponding barrel section. By contrast, the developed in the University of Twente torpedo with perforated, freely rotating sleeve, can be used without affecting the barrel, e.g., to improve mixing of the injection molding extruders. 

Assemblies of small disks are rotated in a planetary movement around a central screw conveyor. The disks are mounted on six hoUow axles and the axles revolve on overhanging bearings from the gearbox at one end of the vessel where they are driven, via a drive shaft, by an electric motor. The filtrate is collected from the disks via the hoUow shafts and a filter valve into a large collecting pipe. The hoUow shafts also collect the water and air from the dewatering process, in another part of the rotational cycle. The number of disks mounted on the shafts can be adjusted for different materials, depending on the required capacity and the cake thickness to be used. 

Most plastics e.g. polyolefins and polystyrenes and their derivatives such as ABS (acrylonitrile-butadiene-styrene) and SAN (styrene-acrylonitrile) are supplied by the manufacturers in ready-to-use form with most of the above-mentioned stabilizers or simply need to be additionally stabilized with other additives, e.g. antistatic agents and HALS stabilizers, as required. On the other hand, in the case of other materials (e.g. PVC) it is the end user who adds the additives, pigments or preparations. This is normally done on fluid or high-speed mixers, although in the past gravity mixers or tumble mixers were also used. The mixture is then homogenized on mixing rolls, kneaders, planetary extruders or twin-screw kneaders and further processed. 

In general, the retention of the stationary phase in the coil rotated in the unit gravity field entirely relies on relatively weak Archimedean screw force. In this situation, application of a high flow rate of the mobile phase would cause a depletion of the stationary phase from the column. This problem can be solved by the utilization of synchronous planetary centrifuges, free of rotary seals, which enable one to increase the rotational speed and, consequently, enhance the Archimedean screw force. The seal-free principle can be applied to various types of synchronous planetary motion. In all cases, the holder revolves around the centrifuge axis and simultaneously rotates about its own axis at the same angular velocity w. 

Retention of the stationary phase in the coiled column of the HSCCC system totally relies on the Archimedean screw force generated by the planetary motion of the column. However, this force is often too weak to retain the stationary phase for some polar solvent systems, such as aqueous-aqueous polymer phase systems, resulting in carryover of the stationary phase from the column. 

Screwipaddle blenders Ribbon blenders Orbiting screw blenders Planetary blenders... 

Convection blenders reorient groups of particles in relation to one another as the result of mechanical movement, for example, caused by a paddle or a plow. As a result, circulation patterns result in this type of blenders. Subclasses of convection blenders are typically defined by vessel shape and impeller geometry. Ribbon blenders (Fig. 30), planetary blenders (Figs. 31 and 32), orbiting screw blenders (Fig. 33) are examples of convection blenders. High shear mixers comprise another sub-class of convection blenders that will be discussed separately. 

FIG. 21-157 Examples of low-shear mixers used in granulation, (a) Ribbon blender (h) planetary mixer (c) orbiting screw mixer (d) sigma blender (e) double-cone blender with baffles (/) v blender with breaker bar. (See also Solids Mixing. ) [( ) and (d), Chirkot and Propst, in Parikh (ed.). Handbook of Pharmaceutical Granulation Technology, Taylor 6- Francis, 2005.]... 

In these extruders, six or more evenly spaced planetary screws revolve around the circumference of the central or so-called sun screw. The planetary screws intermesh with the sun screw and the barrel. The planetary barrel section has helical grooves corresponding to the helical flights on the planetary screws. This section is usually a separate barrel with a flange-type connection to the feed barrel section. 

Various kneader designs (e.g., ram, internal, screw, paddle, Z-, arm, and planetary kneaders. Fig. 7.7) are used to produce highly viscous (pasty) paint concentrates (master batches), uncured rubber compositions, and putties. Kneaders have a high energy consumption because they are generally used to produce systems that have a low binder content or are difficult to wet [7.23]. 

Figure 3 The Slags are Stored in Two Different Silos. The Slags are Fed to the Planetary Mixer by Meems of Screw Conveyors...

All hydrodynamic CCC systems utilize an Archimedean screw force that is created by coil rotation in the force field some use low-speed rotation of the coil in vmit gravity while others subject the coil to a high-speed planetary motion. An Archimedean force drives all objects in the coil toward one end of the coil, which is called the head the other end is called the tail. 

Multi screw extruders Gear pumps Planetary gear extruders Multi (>2) screw extruders Spiral disk extruder... 

There are several types of extruders, which incorporate more than two screws. One relatively well-known example is the planetary roller extruder, see Fig. 2.11. 

---