Calorimetric tests

The heat generation on contact with water must also be considered. Here, one of the calorimetric tests described previously in this chapter may be used. 

Heat of combustion, thermal conductivity, surface area and other factors influencing pyrophoricity of aluminium, cobalt, iron, magnesium and nickel powders are discussed [4], The relationship between heat of formation of the metal oxide and particle size of metals in pyrophoric powders is discussed for several metals and alloys including copper [5], Further work on the relationship of surface area and ignition temperature for copper, manganese and silicon [6], and for iron and titanium [7] was reported. The latter also includes a simple calorimetric test to determine ignition temperature. 

Burning , etc are listed in Vol 1, p IX Calorimetric Tests for Explosives, Propel- Coefficient de self-excitation (CSE). Fr test for sympathetic detonation. See Vol 3, p C390-L... 

Trauzl Test (5-6) Plate Dent Test (6) Detonation Rate (6) Booster Sensitivity Test (6) Calorimetric Tests (6-7) 60-mm... 

The peak gas evolution rate, QGmax, can be obtained from calorimetric measurements (see Annex 2 and equations (A2.3) and (A2.4)). It is important that such calorimetric tests are performed so as to minimise the amount of dissolved gas in the test. "Open" tests are therefore preferred to "closed" tests[2]. 

Qv and Qg should be evaluated at the same temperature and pressure, usually the relief pressure. QG, the volumetric rate of gas evolution, can be obtained from measurements in a calorimetric test by the use of equations (A2.3) or (A2.4) (see Annex 2). Qv is the volumetric rate of vapour generation and can be calculated, as follows, from the rate of temperature rise in a closed calorimetric test or in an open test with a high superimposed containment pressure (see Annex 2). 

Alternatively, ATH could be measured in a closed vessel calorimetric test, but the pressures used in the small-scale apparatus would need adjusting to account for any difference in gas volume to sample mass ratio from the full-scale reactor.. . 

An open system calorimetric test will tend to measure QGmax, rather than the sum of QGmax and Qvmax, because the vapour produced will tend to condense in the relatively cold containment vessel. A closed system test will also underestimate Qvmax because the high pressure will suppress vaporisation. Qvmax could also be calculated from ... 

It is required to size a bursting disc system with a maximum specified bursting pressure of 2.2 barg (3.2 bara) for a reactor of volume 1.5 m3 and design pressure 3 barg (maximum accumulated pressure = 4.3 bara). The frictional resistance of the bursting disc system in this case is equivalent to 4fL/D = 5. The worst case reaction has been identified as a tempered hybrid, and an open system calorimetric test has demonstrated that it will continue to temper until the reaction is complete. For the worst case reaction, the mass in the reactor would be 860 kg. 

Note that, if the reacting system has a wide boiling range, the measured vapour pressure data will be different to that for the relieving reactor. The composition for the relieving reactor will change due to the preferential vaporisation of the most volatile component(s), but this will not be the case for the closed calorimetric test. 

Before beginning the series of runs to determine the relief size, the physical property and kinetic data need to be correlated in the form required, by the code. In some cases, the code may already have the components required on a database. In all other cases, physical property data must be found, estimated or measured and correlated in the appropriate form. Some codes have a front-end program for curve fitting of data. For tempered systems, the vapour/ liquid equilibrium models are of critical importance since errors will cause the code to open the relief system at the wrong temperature and reaction rate. It is therefore worthwhile to spend time to ensure reasonable behaviour of the vapour pressure predictions. Check that all correlations behave sensibly over the entire temperature range of relevance for relief sizing. A good test for the physical property and kinetic data supplied to the code is to first model the (unrelieved) adiabatic calorimetric test which was used to obtain the kinetic data.. . ... 

A new calorimetric test was performed with this heating rate superimposed. The measured rates of temperature rise in a closed test were 150 K/minute at 2.0 bara and 220 K/minute at 2.6 bara. In each case, the rate of temperature rise due to the reaction can be calculated as ... 

An adiabatic calorimetric test in which the sample is held within a sealed container. See A2.3.1. 

Correction of pressure measurements from a calorimetric test to remove the pad gas pressure and leave the vapour pressure. See A2.7.1. 

Heat of Combustion (Qc), Heat of Explosion (Qe) ond Hoot of Formation (Qf) will he discussed under Calorimetric Tests in Vol II. 

Bomb Calorimeter or Closed Bomb. See under Calorimeter, Calorimetry and Calorimetric Tests... 

Bomb for Determination of Heats af Combustion and Explosion. See under Calorimetric Tests... 

Perez Ara (Ref 26, p65) describes another bomb, called "Burlot-Malsallez . The bomb represented here in. Fig may also be used for calorimetric tests... 

Calorimetric Tests. See Heat of Formation, Combustion, Deflagration, Explosion and Detonation... 

Calorimetric Tests for Explosives, Prepe Monts and Pyrotechnic Composltiens. These tests include detenninsr... 

Calorimetric Tests (or Explesives, Propellants and Pyrotechnic Compositions. These tests include determinations of heat of co ihtts[Pg.707]

---