How to Select Laboratory MixersHow to Select Laboratory MixersHow to Select Laboratory Mixers

Image Credit: Munson M achinery Company, Inc.

 

Laboratory mixers are used to mix, emulsify, homogenize, disintegrate and dissolve samples.

 

Types of Laboratory Mixers

 

There are several basic types of products.

 

  • Dual-shaft mixers use a three-wing or helical anchor to generate flow and remove mixed materials from the vessel wall.
  • Double-planetary mixers use a rectangular or finger-shaped blade to feed material to an orbiting high speed dispenser (HSD).
  • Single-stage rotor/stator devices use a stationary stator to turn an immersed rotor at high speeds. The blades pass each port in the stator and expel material at a high velocity into the surrounding mix.
  • Multi-stage rotor/stator mixers increase shearing to produce smaller particle sizes and more homogenous batches. When two to four rotor/stator pairs are nested concentrically, the mixed material that moves outward from the center of the unit is subjected to a rapid, sequential shearing.

 

Specifications


Selecting laboratory mixers requires an analysis of performance specifications.

  • Speed range and accuracy are usually measured in revolutions per minute (rpm). Some mixers can be operated at variable speeds. Others are designed for continuous speeds.
  • Viscosity range is measured in cycles per second (cps).
  • Capacity, the size of the mixing vessel, is expressed in either liters (L) or gallons (gal).
  • Operating temperature and operating range are measured in degrees Fahrenheit (F) or degrees Celsius (C).
  • Introduction methods - There are two sample introduction methods for laboratory mixers. Continuous devices accept a continuous flow of the sample. By contrast, batch mixers accept only a measured flow or volume.
  • Temperature control - Laboratory mixers with an internal heating or cooling elements are commonly available. Heating elements are usually made of ceramic materials, powered electrically, and measured in watts (W). Smooth cooling shovels that rotate within a drum are used to ensure maximum contact without inter-particle friction.

 

Interface Options

 

Analog front panels include potentiometers, dials, switches or other manually-actuated inputs that allow operators to adjust ranges and control the output. Digital front with numeric keypads or menus are used to perform these same functions.

 

Display Types

 

Video displays consist of a cathode ray tube (CRT), liquid crystal display (LCD), flat panel display (FPD) or other multi-line display.

 

Special Features

 

Intrinsically safe (IS) laboratory mixers will not produce sparks, electrical energy or other thermal effects that would cause an explosion under normal or abnormal conditions.

 

Some laboratory mixers are handheld, but not necessarily portable. Others mount on an overhead stand.

 

Programmable mixers and devices that use a timer are used in many applications.

 

Standards

MIL-M-37408 - MIXER, LABORATORY, HIGH INTENSITY


Related Products & Services

  • Industrial Mixers

    Industrial mixers use a shaft, screw, blades, ribbons, impellers or propellers to mix industrial materials such as adhesives, chemicals, construction materials, minerals, coatings and paints.

  • Laboratory Homogenizers

    Laboratory homogenizers are high-speed, high-shear mixers that reduce samples to uniformed-sized molecules through maceration, cutting, and blending. They are used to process liquids, slurries, or granular substances.

  • Powder and Solids Blenders

    Powder and solids blenders produce a uniform mixture of dry or powdery materials. They are designed for industrial and laboratory environments, and provide either batch or continuous blending.

  • Static Mixers

    Static or motionless mixers are fins, obstructions, or channels mounted in pipes, designed to promote mixing as fluid flows through the mixer.