LARGE TOP ENTRY AGITATORS
TOP ENTRY MIXERS
The need for larger mixers has increased in recent years, mainly due to the industry’s requirement to expand operations, or to keep production costs as low as possible. At AFX, we customise our top entry mixers to accommodate your process. Our top entry mixers are available in different technical specifications and can be used for specific purposes across different industries. In the past, large top entry units were more commonplace in the mining industry. However, this trend is now changing with other industries now also requesting larger and more specialised mixers.
As agitators become larger, the loading requirements increase considerably, and every component is looked at individually, ensuring it is robust enough to handle the application. At AFX, all design work is further scrutinised using Finite Element Analysis (FEA) to ensure that failures do not occur. Many companies tend only to use FEA’s once they have experienced problems or failures. We use FEA’s and our design know-how to avoid problems before they happen.
Components are isolated and designed to handle loads far more than what they would experience during operation. Our software allows us to predict and simulate very accurately what loads will be experienced during operation. Even with this in mind, all our designs are conservative and can tolerate any fluctuating loads and peaks that the plant may experience. These components also have unique design features, such as:
On our larger agitators, gearboxes are designed to incorporate a dry well and heavy-duty output bearings. In the majority of instances, we also allow for an extended bearing distance. Normally, gearboxes are selected on torque alone, but with agitators, the overhung load is large, and the drive is subjected to high external loads. Our selection, therefore, doesn’t only cater for the transmission of power, but also its ability to withstand external forces.
With tanks being larger, the structures the agitator needs to mount onto becomes more susceptible to inaccuracies and misalignment. With the intention of saving costs, many manufacturers allow their gearboxes to be bolted directly onto faulty beam structures. By mounting a machined gearbox directly onto a fabricated structure, it preloads the housing. This causes additional stress within the housing itself. During operation, this misalignment, combined with any twisting of the beams, will cause premature casing failure. AFX-designed gearbox bases have machine mounting surfaces that don’t need shimming and won’t preload the gearbox casing. Bases are designed to withstand much greater loads than what the agitator is subjected to. This enables the base to increase the rigidity of the structure.