Types of the Concrete Mixers and It's Application
Regardless of what people have told you, or what you have read, there is a best mixer for each application. Each excels in a different type of concrete:
Twin Shaft Mixer - Lots of concrete at high speed, low wear, low maintenance. Designed for rough, tough jobs like dam building and ready-mix. Handles aggregate sizes to several inches. Does not discharge completely, so not good for mixes of different type or color. End of shift cleanout is slow and difficult (unless our high pressure washout system is used). Performance on dry cast mixes is not as good as the best planetary mixers. Gives the highest throughput of concrete in a given floor space, can double plant output without modification to hoppers, scales, belts etc. Most models have single discharge door; exception is Camelway which has a double door option. "Compulsory mixing" action gives high quality concrete with maximum strength.
Turbine Mixer - High quality precast, especially wet cast mixes. Medium speed, medium wear, medium maintenance. Designed for precast. Good cleanout but sensitive to blade adjustment and wear. Good for colored mixes. Simple mechanical system. Easy to install moisture sensors in floor. Up to 4 discharge doors. Most models not fast enough to create "Compulsory mixing", so concrete not as high in quality or strength.
Planetary Mixer - Highest quality precast, especially dry cast, block, pavers, architectural. Medium to high speed, medium wear, medium maintenance. Designed for precast, block, pavers. Good cleanout, good for colored mixes. More complex mechanically but best models very reliable. Easy to install moisture sensors in floor. Up to 4 discharge doors. "Compulsory mixing" action gives high quality concrete with maximum strength.
Rotating pan - most of these type mixers are obsolete. Good for precast, both wet and dry cast. Mixing action similar to planetary but mechanically complex, high maintenance. Difficult to install moisture sensors. Single discharge door. Most models not fast enough to create "Compulsory mixing", so concrete not as high in quality or strength.
Drum / tilt up and transit mixing trucks - Slow, poor mixing action takes many revolutions to attain good homogeneity. Critical on charging sequence, requiring initial addition of water to wet blades and help remove deposit from previous batch. Cannot be completely discharged, difficult to clean out and maintain.
Ribbon/Spiral blade - The 'old standard' for precast and block plants. Slow, poor mixing action takes many minutes for good mix. Very little end to end action, so charging method and water entry is critical to avoid variation within discharged batch. Non-compulsory action.