The mixers and Agitators maximize process flexibility by allowing blades to be installed, removed, and changed to various pitches, depending on what works best for the application at hand. From a maintenance perspective, The blades are desirable because individual blades can be replaced if they become damaged, not the entire agitator; hence, the mechanical seal isn’t disturbed and repair costs are minimized.
Homogenizing agitators ; - due to its capacity for intensive dispersing mixing, this type of agitator is perfect for achieving high homogeneity of the product. A homogenizing agitator is able to digest powders, fibrous substances. The turbine may be built in directly in the bottom of a tank or in an additional casing connected with the tank chamber in a closed cycle. There are also in-line systems, where the agitator is an separate device. Such a design permits reduction of investment costs wherever homogenization of the product is not required throughout the process.
Agitator models |
Application |
Advantages |
Disadvantages |
Paddle: · Flat paddles · Finger paddles · Gate paddles |
· Solid mixing · Slurry mixing |
· Heavy duty mixing · Adjustable to 2 or 4 blades · Excellent for low-speed |
· High power consumption · Inefficient liquid circulation |
Counter-rotating paddles |
Paste mixing |
· Efficient in the laminar condition · Blending |
· Vibrates at high speed · Not suitable for liquid mixing |
Tumbling |
Blending |
Paste and viscous material mixing |
Not suitable for fluid solutions |
Disk and cone |
Polymers and dispersionpreparation |
Viscous solution mixing with 60 revolutions per second |
Paste mass cannot be handled |
Free shaft suspension |
Sugar processing |
Suspension, Thickening operation |
High power requirement |
Impeller type |
Emulsion preparations |
· Good temperature control · Creates axial flow · Good phase mixing |
Not for viscous materials |
Turbine agitator · Straight blade · Pitched blade · Vaned disk · Curved blade |
Liquid and gas reactions |
· Excellent for dispersionoperations · Creates good radial flow |
Only for less viscous liquid below 15 to 20 Ns/m2 |
Slotted rotary · Rotating disk |
Powders and |
Unique particle size and homogeny product formation |
· Minimum axial flow · Operates better only for 0.1 to 0.01mm particle size solids |
Screw · Screw in cone |
Food and snack processing |
Homogenization of high viscous materials |
Not suitable for miscibility operations |
Helical · Ribbon type · Helical screw |
Polymer and paints processing |
Handles viscoelastic liquidsthat are more than 20 Ns/m2 |
Less radial flow patterns |
Gate |
Blending operations |
· Good speed control · Handles pseudoplastic liquids |
Not suitable for gas to liquid operations |
Anchor · Round anchor · Combine anchor and gate |
Milk and fat processing |
Efficient heat exchange between the reactor walls and reaction mass (fluids) |
· High power consumption · Requires heavy duty gearbox |
Propeller |
· Dairy and food processing · Chemicals processing |
· Less Metzner –Ott shear rate constant · Homogenization · Good miscibility |
· Motion of liquid starts on one spot · Dead spots formation at high rotation speeds · The occurrence of solids settling at low speeds |
Example
Rotary Airlock Valve Gear Reducer Mixing Tank & Agitator Mixer