TSu | Thermal and Pressure Hazard Screening Platform - H.E.L Group

TSu | Thermal and Pressure Hazard Screening Platform

For identifying thermal and pressure hazards in reaction mixes and raw material liquids and powders.

The TSu (Thermal Screening Unit) enables rapid screening of both the temperature and pressure characteristics of a sample on the same platform.  It is simple to operate, has a small footprint, and offers flexibility of use.  It can be considered a complementary, or even alternative, a technique to the classical DSC/DTA (Differential Scanning Calorimetry/Differential Thermal Analysis) methods.

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The TSu typically finds application in:

  • Thermal reaction screening of reaction hazards in process scale-up
  • thermal stability studies on the reaction waste stream

This is due to its ability to characterize sample pressure changes in addition to thermal behavior, and its capability in supporting relatively large sample measurements.

For effective reaction hazard screening, two critical pieces of data are needed:

  • the onset temperature (Td) of the reaction- where the exotherm is detected
  • the pressure generated by the resultant runaway

Secondary thermal runaway risk












If the MTSR (Maximum Temperature of the Synthesis  )  is greater than the onset temperature (Td) of a component within the reaction mix, an undesired side reaction or decomposition may be triggered, possibly leading to a secondary thermal runaway.

In addition to considering thermal stability, it is also vital to screen for pressure hazards.  Some of the most hazardous reaction mixes are those which involve the production of non-condensable gases. The TSu provides critical information on the associated pressure change, which is vital for assessing the over-pressurization hazard.

The TSu’s ability to support relatively large volume measurements (0.5 ml to 10 ml), enables representative samples of the reaction mix to be screened and reliable data to be determined for the reactants, intermediates, and products in the reaction mix. The test cells are available in a variety of materials, enabling a range of sample types to be tested. The test cells are also fully compatible with the Phi-TEC I and Phi-TEC.  This facilitates data comparison and method transfer between the instruments, should the initial hazard assessment on the TSu highlight that a secondary thermal runaway is likely, and that it is necessary to screen the hazard more thoroughly using adiabatic  .

Operating Modes

The principle operation is a simple oven temperature ramp (0.5-10 ° C/min), with sample temperature and pressure allowed to vary independently. Exotherm and gas evolutions are indicated by a spike in the sample Temperature and/or Pressure traces.

Additional operating modes are available as standard including

  • Isothermal (stability)
  • Dual-Scan
  • Soak & Scan


Multiple Units:

Several Thermal Screening Units can be used in parallel, running from the same computer. This is a cost-effective method of screening large numbers of samples. The compact design of the instrument makes it easy to fit several units into a standard fume cupboard.