James Burelbach, PhD, Process Safety & Business Development Leader, Fauske & Associates, LLC
The Advanced Reactive System Screening ToolTM (ARSST) is a popular low thermal-inertia safety calorimeter. It is commonly used to quickly obtain directly scalable data on chemical reactivity hazards and thermally unstable substances. The ARSST provides reliable adiabatic data which can be used for a variety of safety applications including emergency relief system design DIERS vent sizing, studies of material compatibility or thermal stability, and sometimes just to better understand the unintended (or intended) reaction chemistry. ARSST data include adiabatic rates of temperature and pressure rise (dT/dt and dP/dt) during a runaway chemical reaction which can be directly applied during process scale-up to size pressure relief vents and quench or knockout tanks and to underpin other aspects of process safety management. Developed by Fauske & Associates, LLC (FAI) the ARSST has options for customization such as a high-pressure vessel and flow regime detector.
The ARSST is based on DIERS technology which is recognized by OSHA as an example of good engineering practice. This easy-to-use device is an excellent tool for industry as well as any university engineering lab for research or unit operation studies (a SACHE module was developed for ARSST education).
ARSST tests are routinely used to model such diverse upset scenarios as loss of cooling, loss of stirring, mischarge of reagents, mass-loaded upset, batch contamination and fire exposure heating.
Such low thermal inertia adiabatic calorimetry data are essential for mitigation of chemical reactivity hazards.
The ARSST typically uses a relatively small yet representative sample size of 5-10 grams in a lightweight glass test cell with a volume of approximately 10 ml. Test cell volumes of 5 ml or 20 ml are sometimes used. The test cell is outfitted with a belt heater and then installed in a 350 ml (or 450 ml) pressure containment vessel. ARSST tests are typically run using open test cell methodology. In the open test configuration, the test cell is open to the containment vessel and boiling of the test sample is prevented by imposing an inert gas backpressure within the containment vessel.
We are sometimes asked this question by customers who wish to get the most out of their ARSST apparatus. Closed cell testing is an ARSST innovation that has been available for several years, although it is not as commonly used as open cell testing. Some reasons to consider closed cell ARSST testing are:
Below are some illustrations and examples from work we have done using the closed cell ARSST. We hope this information is of interest to ARSST users who look for innovative ways to get the most use out of their ARSST.
20 ml 10 ml 5 ml
Closed Cell ARSST Insulation Options
Closed Cell ARSST: Sample Addition
Closed Cell ARSST: Pressure Balancing
Example 1. ARSST Closed (vac) vs. Open (300 psi)
Example 2. ARSST Screening for Energetic Decomposition
Example 2. Open and Closed Cell ARSST
Example 3. P-T Data
Example 4. Closed cell BA tests in ARSSTTM & VSP2TM
Example 5. Closed cell AIBN/BA Induction Tests
2°C/min heater calibration → 0°C/min calibration
If you are interested in more information on ARSST, dig deeper with out white paper on quick hazard screen by closed cell ARSST using standard ARC bombs below.
Quick Hazard Screening by Closed Cell ARSST Using Standard ARC Bombs