Flex-Mix™ Pilot Mixer

Product Type(s) : In-Line Mixers
Description :

Flexibility to test mixing products from low to high viscosity in small batch sizes. Ideal for recipe development and small batch production.



The Flex-Mix™ Pilot is a flexible, skid-mounted mixer specifically designed for high shear mixing via the rotor/stator principle. It features the flexibility to test a wide range of products from low to high viscosity in a small batches. It’s efficient, improves speed to market, and because it’s from SPX FLOW, you know it’s reliable.

Available either to rent or purchase, the Flex-Mix Pilot enables you to perform high-shear mixing and blending in your own labs to replicate actual process conditions. These in-house tests provide a clear direction to whether products and recipes can be replicated on a larger scale which translates to more efficiency by not having to shut down an active line for testing.

Flex-Mix Pilot mixer comes equipped with all the features of a full-scale mixer, including heating jackets, agitators, scrapers and semi-automation systems. It performs three types of testing - mixing, direct heating and jacket heating and cooling.

The range of ingredients that can be tested in the Flex-Mix Pilot include liquids, dry powders, soluble pastes, coarse grinds and solids.

This pilot mixer now enables customers to test in just one unit the three different types of mixing techniques available in the full scale APV Flex-Mix™ series: 

  • Atmospheric mixing for low viscosity products like ice cream mix and recombined dairy products.  It used internal recirculation and scales up to our Flex-Mix™ Liquiverter mixer.
  • Vacuum-mixing for low viscosity products like infant formula and plant based products. It uses external recirculation and scales up to our Flex-Mix™ Instant mixer.
  • All in one mixing with or without vacuum or heating for medium and high viscous products like processed cheese and meat products. It uses internal recirculation and scales up to our Flex-Mix™ Multiverter mixer.
Theory of Operation

How It Works

The Flex-Mix Pilot’s rotor/stator mixer pump generates a flow that can be recirculated internally in the mixer tank or recirculated back to the tank in an external loop. The agitator adjusts from active for high viscous products, or removed altogether for low viscous applications. In vacuum configurations, the dry matter (powder) can be sucked into the tank below the liquid surface.

A vortex sucks both powder and liquid down toward the rotor/stator mixer pump, ensuring that powders and particles added through the top of the tank will also be drawn down into the mixer pump. In both the mixer pump rotor and the surrounding stator, high shear forces and turbulence are created for effective and homogeneous mixing.

For high viscous products, the scraper blade agitator runs to create additional mixing while removing product film from the tank’s side wall.

Note: For external recirculation of high viscous products, a positive displacement booster pump will be necessary for leading the product back into the tank.



  • All product contacting areas are made of stainless steel AISI 316/ DIN 1.4401
  • Seal material in EPDM or FPM (Viton), FDA quality
  • Interior surfaces in 3A finish, Ra 0.8 micron with polished weld
  • Sanitary design for CIP cleaning
  • Panel screen for control. Partly manually operated.

Tank design

  • Circular tank with a cone shaped bottom
  • Pressurized (multi duty) or full vacuum tank (basic)
  • Heating/cooling jacket on tank and wall and with insulation of the outer jacket
  • Top mounted liftable manway cover with safety lock (multi duty)
  • Top mounted manway cover with safety lock (basic)
  • Side mounted inlet for minor ingredients
  • Bottom mounted inlet for powder suction
  • Bottom mounted mixer outlet
  • Vacuum connection on manway
  • Top mounted scraper blade agitator (multi duty)
  • One CIP inlet branch, Ø25 mm with rotary spray ball

Bottom mixer

  • A vertically mounted mixer pumping unit with a variable speed control. 7.5 kW IEC motor, 2 poles
  • 2 stator types (exchangeable) for internal or external mixing set up
  • Double mechanical shaft seal. Product side in SiC/SiC and atm.
  • Side in SiC/CTop entry agitator (multy duty)
  • Top mounted anchor type agitator
  • Variable speed controlled 2.2 kW motor with scraper blades acting on the side wall
  • Removable for low viscous products (instant duty)
  • Double mechanical shaft seal. Product side in SiC/SiC and atm. Side in SiC/C


The Flex-Mix™ Pilot Mixer includes: