Stamixco
Static Mixing, Reaction, Heat Transfer & Fluid Dynamics Technology
USA: +718.748.4600
Switzerland: +41.52.338.17.11

Lift Tab Static Mixer (Type LT)

The Type LT Lift Tab static mixer (Figure #1) has no moving parts and no leading edges or crossing blades with pinch points that act as sites for material hang-up. This results in eliminating all fears of plugging or fouling when mixing solids with solids, mixing solids into liquids and injecting chemical additives (liquids, solids or gases) into slurry and sludge streams. If you can gravity feed or pump the material, the Type LT Lift Tab static mixer will mix it without fouling or plugging.

Figure #1: Plastic Disposable & Metal Static Mixers
Figure #1: Type LT Lift Tab Static Mixing Unit in various housing option configurations

Principles of Operation

Each Type LT Lift Tab mixing element has three tapered finger-like blades protruding from the inside pipe wall into the flowing fluid at a 45o slope in the direction of process flow (as in a ski-jump). The mixing elements have no moving parts and no leading edges or crossing blades with pinch points that act as sites for material hang-up. Individual mixing elements have a length/diameter ratio of 1.0 and adjacent mixing elements are oriented 90o. These 45o slope finger-like mixing blades force the liquids and solids to continuously divide and recombine in a repeatable geometric sequence as material flows along the entire length of the mixing unit. The mixing performance is far greater and more predictable than that which can be achieved by empty pipes, baffled pipes, rotating shafts with blades welded to the shaft, sludge pumps, baffled tanks, mixing valves, ring injectors, tanks with mixing paddles, etc.

The Lift Tab mixing elements are fabricated with options of long, medium and short length middle fingers (Figure #2, #3 and #4). With a long middle finger (Figure #2), the smallest gap between adjacent mixing blades results which creates a high degree of mixing in a short length, but the structure is susceptibility to plugging with solids larger than the mixing blade gap. Alternatively, a short middle finger (Figure #4) results in the largest gap between adjacent mixing blades which allows very large solids to pass through the mixer without plugging but requires multiple mixing elements to create the mix quality of one long middle finger mixing element. Additional considerations for middle finger length include pipe size vs. size/shape of solids to be mixed, flow regime of the process fluid (laminar, transitional or turbulent flow), the degree of mixing required and maximum allowable pressure drop and length.

Figure #2: Long length Middle Finger for processing small particles and for use in laminar flow applications
Figure #2: Long length Middle Finger for processing small particles and for use in laminar flow applications
Figure #3: Medium Length Middle Finger for processing fluids with medium size particles and for use in 
laminar/transition flow applications.
Figure #3: Medium Length Middle Finger for processing fluids with medium size particles and for use in laminar/transition flow applications.
Figure #3: Medium Length Middle Finger for processing fluids with medium size particles and for use in 
laminar/transition flow applications.
Figure #4: Short Length Middle Finger for processing fluids with large particles and for use in turbulent flow applications.

Features & Applications

Features

  • Non-fouling design
  • Low Shear rate assures no destruction of soft solids such as fruit structures in yogurt
  • Short length, hence small space requirements
  • Fits in-line and can retrofit into existing piping
  • No moving parts, hence no maintenance or spare parts
  • Removable mixing elements
  • Constant mixing performance over a wide flow rate range
  • Low pressure drop/energy consumption

Applications

Waste Water Treatment Applications:

  • Flash Mixing: Reactive chemical admixing
  • PH Control: Acid or Base admixing, reaction and neutralization
  • Flocculation: Admixing of Flocculants & Coagulants
  • Nutrients: Addition of Nutrients
  • Disinfection: Injection of Chlorine, Fluorine, Ozone
  • Oxygen Boosting: Inject Air to decrease COD
  • Sludge Conditioning: Admixing of Filter Aids, polymers, nutrients, additives, chemicals, etc.

Process & Food Industry Applications:

  • Blend, bleach and condition pulp stock
  • Treat sewage and waste sludge
  • Admix solid food pieces such as fruit into yogurt
  • Mix treatment chemicals into mining and heavy oil slurries
  • Solids Mixing: Mix solids by gravity flow
  • Blend additives into pneumatically conveyed powders/pellets

More Information