Monitoring mixers and mixtures

what their investigations have been exploring is the chaos producing system of the mixer, and then pronounces the mixer at satisfactory from that perspective, one receives very little guidance as to how a wide-size-range powder or a cohesive powder will disperse within that same powder mixer. In this overview of techniques for monitoring the performance of mixers and exploring the structue of mixtures we will attempt to delincate exactly what was achieved in any particular study. In the next section, a new technique for monitoring the chaotic producing behavior of a mixer called 'Poisson tracking' will be described.

Poisson tracking as a technique for studying chaotic conditions in a powder mixer

Here, we distinguish between tracers and trachers. A tracer is an ingredient that is meant to trace out movements within a powder mixing system in the same way that tracer bullets make the missiles of a machine visible to the gunner. One user tracers to find out directions and pathways within a powder mixer. When using trackers, we have no concern at all as to how a fineparticle designated as a tracker gets to a certain location, we just monitor how frequently tracker occur in a sample from a specified location.

Mixer and powder mixing mechanisms
The simplest type of powder mixer which have been employed in industry is the horizontal rotating drum. In such a device the powders to be mixed are added to the drum, which is then set into a rolling motion with the powder rising up the wall and cascading down, as illustrated in figure. The volume percentage of the drum filled with powder is called the powder charge, a quantity sometimes expressed as a fraction of the internal volume of the powder mixer.

The powder charge must not be too large or there will be insufficient freedom of motion within the mixer for the powder to mix. the speed of rotation cannot be too high because at high speeds of rotation the powder will be centrifuged to the walls and held in position. The only real mixing mechanismin such a drum is the random motion of the fineparticles of the powder as they cascade down the moving surface of the powder. This fact is indicated in figure. For reasons that will become more apparent as our discussion proceeds, a horizontal rotating drum mixer is classified as an active, captive, mixer. This name indicates that parts of the mixer move, but that the mixing container remains in a fixed position relative to the general geometry of the mixer and to the driving mechanism activating the mixer. From a technological perspective one would not normally expect the rotating drum mixer to be particularly efficient since there are relatively few randomizing actions within the movement of the mixer.