Thermal Cascade
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Oscillatory Flow Reactor Patent pending
Oscillatory flow reactors (or oscillatory baffle reactors) drive a primary reagent stream through a tube while a second reagent is injected, creating a chemical reaction between the two. An oscillating piston sloshes the primary stream back and forth through an insert geometry to promote mixing.
Currently, oscillatory flow reactors are used in the manufacture of pharmaceuticals and fine chemicals — from paracetamol to cancer medication.
The commercial case
Thermal Cascade's redesign of this device promotes the desired reaction path, leading directly to improved yields or savings from reduced purification costs.
The design allows for retrofitting existing devices, with 3D-printable mixing cartridges made to slot in, alongside changes to piston operation.
Optimal operation and cartridge inserts depend on the exact duty and reaction performed.
What we design for
In competitive–consecutive chemistry, the product formed from our two reagents can go on to form an unwanted by-product if it reacts with one of those two reagents — i.e. A + B → R, then R + B → S, or R + A → T. High local concentrations of a single reagent (poor mixing) are the main cause of these unfavourable reactions. We use physics and inverse-design principles to improve mixing.
Examples include nitrations, halogenations, diazotisations and azo couplings, organometallic additions, and fast ionic polymerisations.
This is the main current use of this reactor. It requires correct levels of supersaturation of reactants, whilst also ensuring peak shear and thermal dissipation are low — which equally suits other shear-sensitive products such as flocs, cells and emulsions. We design for these duties separately.
Quench and neutralisation steps also benefit from smooth, edge-free flow.
The mechanism
Reagent B is injected into the main flow of reagent A in pulses according to the waveform of reagent A's oscillation: we time injection with the sloshing. In practice it is a pump programme and a sync signal; a passive, electronics-free version is also possible, using a pressure-actuated one-way element opened by the oscillating pressure at the feed port.
The result
In simulation, phase-gated dosing held about 81–91% of the instantaneous-mixing ceiling at every operating point and internals configuration tested, while continuous feed reached at most about 79% at any velocity ratio up to ψ = 40. Pulse dosing at the highest throughput tested still beat continuous feed at any throughput — at matched time-averaged dose.
The operating window
Raising the ratio of the sloshing motion to the net velocity of fluid through the pipe (ψ) buys mixing quality and plug-flow quality together, at essentially unchanged dissipation. However, lowering throughput reduces the net output of product.
The hardware
Mixer inserts are printable cartridges of multiple elements in series, ending in a smooth converging–diverging constriction with no sharp edges. The insert differs for crystallisation and selectivity duties: purely mixing-based optimisation for selectivity, and smoother profiles for crystallisation to lower peak strain.
If you have a selectivity-limited reaction — especially one already running in an oscillatory or baffled reactor — we'd like to hear about it. Technical briefings available under NDA.