There are many key factors that need to be considered when choosing a mixing agitator. A mixing agitator is in fact a complicated piece of machinery, yet at the same time, simple. Regardless of how experienced or not you are, here are the three key elements you should consider before purchasing a mixing agitator.

Shear

These days, many mixing operations are guided by the rule of thumb – apply as much shear as possible without causing excessive shear or heat to the mixing ingredients. In cases when the shear of the mixing agitator is low, it can be increased by increasing the speed of the high shear devices. This can be done by switching to simple design (increases mechanical and hydraulic shear, but decreases the flow) and by reducing the tolerances between the rotor and stator. Greater circulation and a faster cycle can be stimulated in the vessel. This benefit alone represents an increase in per-batch production.

Viscosity

When choosing a mixing agitator, viscosity and product density are important factors to consider. Most industries look for agitators with higher viscosity and reduced discharge of volatile organic products. Many manufacturers of mixing agitators try to produce improved product performance and the result is that the agitators today are customizable for operations near the high end of their viscosity range. But as the viscosity impacts the flow and influences the operation of the three main agitators of the mixer significantly, it needs to be limited. For this purpose, the viscosity is modified during the batch cycle to allow the application greater shear without excessive heat transfer. So, the viscosity should be watched carefully and the three agitators operated in approved combinations only.

Flow

Each mixing process requires a mixing agitator that will secure a constant flow of material throughout the mixing vessel. A constant flow helps the mixing agitator to achieve a complete batch turnover and higher level of homogeneity as the mixing material circulates. It also helps to prevent excessive heat by the high-shear agitators. The importance of energetic and constant flow seems simple, but from a traditional point of view, it prevents thermal damage and prevents excessive heat from the high-shear agitators. Operators who want to push the process, need to check the value of flow from different perspectives. Even the smallest improvement in flow and capacity of heat transfer can be essential, as they might open an opportunity to apply greater shear. This can shorten the mix cycle and increase the output efficiency of the mixing agitator.

Continuing from part 1: Ways To Select The Right Mixing Agitator For The Application