New Magnetic Mixer Saves Energy While Maximizing Product Yield

What is Industrial Mixing?

Modern industrial processing almost always involves some form of product mixing. With the right type of mixer, it is possible to mix a solid, liquid, or gas into another solid, liquid, or gas. It should be noted, though, that efficient mixing can be difficult to achieve on an industrial scale. A great deal of engineering effort goes into designing and improving mixing processes.

Mixing of liquids frequently occurs in the hygienic processing industries. Industrial-scale mixers are commonly used in the food & beverage processing, dairy, pharmaceutical manufacturing, and biotechnology industries.

Mixers are used for a variety of applications: 

• Improve product quality
• Coat particles
• Dissolve soluble solids in liquids
• Blend different types of powders
• Alter material properties
• Maintain homogenous media
• Liquid/liquid blending
• Heat transmission
• Fermentation
• Suspension

Industrial mixing may be done in several different ways: in batches (sometimes referred to as in-tank), in-line (sometimes referred to as continuous) with the process, or with the help of static mixers. There is a wide range of technologies used in industrial mixers that are designed for hygienic applications. 

Some of the most common mixing technologies include the following:

Overview: The Alfa Laval Levimag Magnetic Mixer

Alfa Laval is a Swedish company, founded in 1883. The company’s products are used to heat, cool, separate, and transport various materials, including oil, chemicals, water, beverages, food, starches, and pharmaceuticals. 

Alfa Laval is a premier supplier of the hygienic pumps and mixers used in CSI process systems.

Advantages

In comparison to other turbine-type mixers, the LeviMag offers some unique features:

1. Levitated Design. The levitated impeller makes this mixer fully drainable and minimizes wear. It also provides greater process flexibility to handle a wide range of fluid types and mixing duties, ranging from high intensity mixing to the careful blending of product ingredients.
2. Replaceable Bearings. Both the female and the male bearings can be replaced by the end-user on-site.
3. High-Efficiency Impeller. Designed for low-shear mixing, the impeller unit provides for gentle treatment of the product being mixed.
4. Mixing to the Last Drop. The four-wing, levitated design of the LeviMag’s impeller and the mixer’s dry running capabilities combine to make it possible to achieve maximum product yields.
5. No tank penetrations, shafts, or seals. The weld plate becomes an integral part of the tank wall assuring complete containment and zero risk of contamination.
6. Product flow from this mixer is optimized for the greatest efficiency and the lowest energy consumption.
7. The open design, low-speed rotation, and full drainability optimizes cleaning-in-place, contributing to effective residue removal and minimal contamination from wear particles.
8. Designed with ease of maintenance in mind. This mixer experiences minimal downtime in normal production operations, and the LeviMag does not require spare impellers. Tools for ready servicing are also available.

Depending on duty and media properties, the LeviMag is configurable for use in tanks ranging in volume from 30 liters to 40,000 liters. Two different model types of this magnetic mixer with five impeller diameters are available.

Each of the two LeviMag models comes with the ability to tailor the mixer’s configuration to meet specific customer needs.

Also, several different drive unit configurations are available, including an epoxy-painted, TEFC (fan-cooled) version and another with a cleanroom finish with a sealed conversion treatment (smooth and closed, with no fan ventilation). An extended console may also be specified for use in insulated tanks.

Disadvantages

In comparison to directly-coupled turbine mixers, where the turbine rotor is directly attached to the motor via a rotating shaft, magnetic turbine mixers really only come with a few disadvantages, but these should be considered when considering this type of mixer.

1. Complexity - In comparison to directly-coupled designs, magnetic turbine mixers are more complex in design, and the magnetic assembly between the motor and the turbine wheel is an additional part that can wear out over time.
2. Mixing torque - Perhaps more significantly, magnetic turbine mixers do not provide the torque at the turbine wheel that is available to a directly-coupled turbine mixer, so the mixing wheel can slip when required to mix certain highly viscous liquid products. For this reason, magnetic turbine mixers are best used for mixing and combining low-viscosity, <1000 Cp, fluids and dry ingredients.
3. Volume of materials to be mixed - Finally, because smaller turbine wheels are easier to spin magnetically than larger turbines, the mixing impeller in these types of mixers tend to be smaller in size in comparison to directly-coupled designs. As a result, magnetic turbine mixers are generally most efficient in mixing and stirring relatively smaller volumes of materials in a tank or vessel. In the case of the LeviMag, volumes of up to 10,500 gallons (40,000 liters) are capable of being mixed. Maximum mixable volume will vary by application.