Two changes to the VHP cycle.
A cycle is usually held up by two things: a continuous tunnel that couples every station to every other one, and an aeration phase that has to run long enough to get residual peroxide down. We work on both.
Modular batch, instead of a continuous tunnel
A continuous tunnel makes one long chain out of the whole line. Every station depends on the containment flow of its neighbours, so an interruption anywhere stops everything, and throughput can only be changed by rebuilding the tunnel. We break the line into independent modules that hold sterility assurance on their own.
- Modules decouple their cycles, so one stopping does not stop the rest of the line.
- Throughput is set by module count. Add chambers to scale up, remove them to scale down.
- An interruption is handled inside a single module rather than across the whole tunnel.
Aeration, which is where the time goes
Aeration is normally the bottleneck. Peroxide has to desorb from surfaces and be carried out of the chamber, and until residual H₂O₂ is low enough the load cannot be released. Shortening that phase without loosening the release limit is an airflow and thermodynamics problem, so that is how we treat it.
- Airflow, temperature and moisture tuned to accelerate peroxide desorption.
- Chamber geometry designed for the aeration phase rather than inherited from gassing.
- Evaporation modelled from vapour pressure and activity coefficients, not a fitted curve.
Case study: tiramisu spoilage
To test the reasoning on something with a measurable outcome, we modelled microbial spoilage in tiramisu and traced how decontamination parameters move the shelf life.
| Tiramisu spoilage calculator Interactive model of microbial reduction and shelf life. | Open |
| User guide What each input means and how to read the output. | Read |
| Validation plan What we set out to test, and the acceptance criteria. | Read |
| Test results What came back when the plan was executed. | Read |
These four open in their own light-paper styling, kept from when they were written.
Where this goes next
The two threads meet in one system: modular chambers that can be added or removed to set throughput, each running an aeration phase short enough that it stops being the constraint. That is the configuration we are validating now.