Burning-quality index

Burning-quality index an empirical numerical indication of the likely burning performance of a furnace or heater oil derived from the distillation profile (q.v.) and the API gravity (q.v.), and generally recognizing the factors of paraffinicity and volatility. 

Kerosene can vary widely in its burning quality as measured by carbon deposition, smoke formation, and flame radiation. This is a function of hydrocarbon composition—paraffins have excellent burning properties, in contrast to those of the aromatics (particularly the polynuclear aromatic hydrocarbons). As a control measure the smoke point test (ASTM D-1322, IP 57) gives the maximum smokeless flame height in millimeters at which the fuel will burn in a wick-fed lamp under prescribed conditions. The combustion performance of wide-cut fuels correlates well with smoke point when a fuel volatility factor is included, because carbon formation tends to increase with boiling point. A minimum smoke volatility index (SVI) value is specified and is defined as ... 

In order to maintain high energy efficiency and ensure a long service life of the materials of construction in the combustion chamber, turbine and jet nozzle, a clean burning flame must be obtained that minimizes the heat exchange by radiation and limits the formation of carbon deposits. These qualities are determined by two procedures that determine respectively the smoke point and the luminometer index. 

When a customer agrees to purchase gas, product quality is specified in terms of the calorific value of the gas, measured by the Wobbe index (calorific value divided by density), the hydrocarbon dew point and the water dew point, and the fraction of other gases such as Nj, COj, HjS. The Wobbe index specification ensures that the gas the customer receives has a predictable calorific value and hence predictable burning characteristics. If the gas becomes lean, less energy is released, and if the gas becomes too rich there is a risk that the gas burners flame out . Water and hydrocarbon dew points (the pressure and temperature at which liquids start to drop out of the gas) are specified to ensure that over the range of temperature and pressure at which the gas is handled by the customer, no liquids will drop out (these could cause possible corrosion and/or hydrate formation). 

The burn rates of propellants are determined in a strand burner (Crawford bomb/ acoustic emission technique) at various pressures using an inert gas for pressurization. This data, when fitted in the empirical relation r = a.P" provides the pressure index n and the coefficient a. This technique is highly useful as a first approximation and is extensively used for propellant screening and quality control. The bum rates at different pressures are also determined by static testing in a ballistic evaluation motors (BEMs) and burn rates are typically scaled up from 1-5% for full scale motors. 

The other important attributes of polycarbonate are transparency (a quality shared with all other unadulterated amorphous thermoplastics) and nonflammability the critical oxygen index is 25% for unfilled polymer. However, with this index, it is likely that PC would continue to burn in a hot environment. Also on the debit side, the chemical resistance is not outstanding, and satisfactory weathering resistance is only achieved with additives. 

Oxygen Concentration to Support the Candle-Like Combustion of Plastics (Oxygen Index), and internationally as ISO 4589-2 Plastics—Determination of Burning Behavior by Oxygen Index—Part 2 Ambient-Temperature Test. The test does not correlate well with other fire and flammability tests nor does it provide a reliable indication of material performance in real fires. However, the results appear to be very sensitive to the composition of the material and the test is therefore ideally suited to serve as a quality assurance tool of fire-retardant-treated materials. 

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