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Process Intensification
Rethinking industrial chemistry

Spinning Tube in a Tube

spinning tube in a tube reactor
 

Introduction

The Spinning Tube in a Tube STTTM process helps substantially improve profits in chemical, petrochemical, biodiesel, pharmaceutical and bio-chemical operations through a paradigm leap from volume-based to area-based reaction systems.

STTTM Reactor Basics

Below is a diagram of a typical STTTM reactor.  Reactant fluid A is instantaneously mixed with reactant fluid B in the STTTM reactor with zero eddy decay.   This can be accompanied with an optional gas or catalyst to complete or accelerate the reaction.  The necessary residence time is controlled by the reactants' feed rates, as well as by the rotor speed.  Separate temperature zones allow unprecedented temperature control of the reaction, including staging different temperature profiles for the complete reaction.   The sub-Kolomogoroff eddies generated in the STTTM Reactor promote quick and efficient mixing of the reactants in a fraction of the time and power expended in conventional systems.

spinning tube in a tube reactor process

Why Is The STTTM Reactor Revolutionary?

Process rates in reactors are influenced by the minimum length of turbulent eddies and the molecular-diffusive mixing time.  The process rate time can be estimated using Einstein's diffusion equation:

einstein's diffusion equation

The STTTM Reactor Process is capable of creating sub-Kolmogoroff and near-Kolmogoroff eddies and therefore can drastically reduce reaction time.  The sub-Kolmogoroff eddies are possible through two dimensional containment of the fluid and zero eddy decay.  Mixing power requirements and reaction time are drastically reduced compared to conventional reactors.

How Does The STTTM Reactor Work?

how the spinning tube in the tube reactor works

A tube is made to spin inside another tube, whereby only a very fine annular gap between the inner diameter of the outer tube and the outer diameter of the inner tube is maintained. This gap is concentric and is filled with the reactants. 

Immediately upon entry of the reactants, almost instantaneously a very large interfacial contact area is produced which is subject to extreme rates of surface renewal.

Typical shear rate values are in the range of 30,000/sec. to 70,000/sec.

shear rate equation

Advantages:

Maximum Mass Transfer Rates

  • Area rather than volume based operation

  • Highest possible shear rates

  • Uniform shear stress throughout the reaction zone

  • Molecular-sized eddy currents reduce reaction times

  • No eddy decay gives high surface area renewal rates

  • Reduction or elimination of unwanted by-products

Maximum Heat Transfer Rates

  • Area rather than volume based operation

  • Heat transfer film coefficients of up to 10,000 W/ m2 -°K or 1,760 BTU/ hr-ft2 -°F

  • Temperature control of +/- 1°C

  • Reduction or elimination of unwanted by-products from wall effects

  • Extremely small, discrete heating zones are possible

Maximum Phase Interaction

  • Area rather than volume based operation

  • Immiscible materials rapidly interact

  • Perfect homogeneity

  • Ideal for emulsification

  • Up to 95% solids loading

Benefits: Benefits as a Result of the STTTM Geometry

  • Smaller size reduces plant floor space

  • Negligible hold-up volume

  • Continuous operation

  • Eliminates scale-up issues

  • Instantaneous self-cleaning

  • Significantly lower hoop stresses

  • Hermetically sealed operation reduces hazards

  • Product discharge rate independent of shear rate

  • Easily coupled to other processing steps

  • LOWER CONSTRUCTION and OPERATING COSTS!!!

Chemical Reactor Applications:

  • Biodiesel (Single Continuous Reactor)

  • Rearrangement

  • Addition-Elimination

  • Substitution

  • Condensation

  • Polymerization

  • Catalysis

  • Electrochemistry

  • pH Adjustment

  • Fermentation

  • Photochemistry (photochlorinations) when stator is made of quartz

 

Please call for further information

R.C. Costello & Assoc., Inc.
1611 S. Pacific Coast Highway, Suite 210
Redondo Beach, CA 90277
Tel: (310) 792-5870, Fax: (310) 792-5877
E-MAIL: rcca[at]rccostello.com