scholarly journals Fire Characteristics of Polyethylene Dust

Author(s):  
Marián Škvarka ◽  
Richard Kuracina ◽  
Zuzana Szabová

Abstract Dust is a product or by-product in many industries. To ensure effective measures of explosion prevention, it is necessary to know the fire properties of dispersed and settled dust. These parameters cannot be calculated, but can be determined on the base of measurements in standard equipment. The article deals with the measurement of fire properties of polyethylene. The values of the minimum ignition temperature of settled and dispersed dust (MIT) and the values of explosion characteristics of polyethylene dust cloud lower explosion limit (LEL), maximum pressure Pmax and maximum rate of pressure rise (dp/dt)max were measured. The measurements were performed on the equipment according to the STN EN 80079-20-2: 2016 Standard Explosive atmospheres - Part 20-2: Material characteristics - Combustible dust test methods and according to the STN EN 14034 + A1: 2011 Standard Determination of explosion characteristics of dust clouds. The MIT of the settled dust was not determined (the sample melted), the MIT of the dispersed dust was 435 °C. The maximum explosion pressure Pmax reached 7.0 bar, and the maximum rate of pressure rise dP/dt was 37.5 bar.s−1.

Author(s):  
Richard Kuracina ◽  
Zuzana Szabová ◽  
Matej Menčík

Abstract A dust explosion occurs when an airborne combustible dust cloud encounters an effective ignition source. The resulting pressure and temperature increase can severely injure people and damage surrounding equipment and buildings, and therefore needs to be prevented or controlled (Taveau, 2016). The article deals with the measurement of maximum explosion pressure and maximum rate of explosion pressure rise of sugar dust cloud. The measurements were carried out according to STN EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds, the maximum rate of explosion pressure rise according to STN EN 14034-2+A1:2012 Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds and Determination of explosion characteristics of dust clouds. Part 3: Determination of the lower explosion limit LEL of dust clouds. The sugar dust cloud in the chamber is achieved mechanically. The testing of explosions of sugar dust clouds showed that the maximum value of the pressure was reached at concentrations of 1000 g/m3 and its value is 6,89 bars.


Author(s):  
Richard Kuracina ◽  
Zuzana Szabová ◽  
Pavol Čekan

Abstract The article deals with the measurement of maximum explosion pressure and the maximum rate of exposure pressure rise of wood dust cloud. The measurements were carried out according to STN EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds and the maximum rate of explosion pressure rise according to STN EN 14034-2+A1:2012 Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds. The wood dust cloud in the chamber is achieved mechanically. The testing of explosions of wood dust clouds showed that the maximum value of the pressure was reached at the concentrations of 450 g / m3 and its value is 7.95 bar. The fastest increase of pressure was observed at the concentrations of 450 g / m3 and its value was 68 bar / s.


Author(s):  
Richard Kuracina ◽  
Zuzana Szabová ◽  
Denisa Pangrácová ◽  
Karol Balog

Abstract The article deals with the measurement of explosion characteristics of wheat flour. The measurements were carried out according to STN EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds, the maximum rate of explosion pressure rise according to STN EN 14034-2+A1:2012 Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds and LEL according to STN EN 14034-3+A1:2011 Determination of explosion characteristics of dust clouds: Determination of the lower explosion limit LEL of dust clouds. The testing of explosions of wheat flour dust clouds showed that the maximum value of the pressure was reached at the concentrations of 600 g/m3 and its value is 8.32 bar/s. The fastest increase of pressure was observed at the concentration of 750 g/m3 and its value was 54.2 bar/s.


Author(s):  
Z Huang ◽  
S Shiga ◽  
T Ueda ◽  
H Nakamura ◽  
T Ishima ◽  
...  

Cycle-by-cycle variations of natural gas direct injection (CNG DI) combustion were studied by using a rapid compression machine. Results show that CNG DI combustion can realize high combustion stability with less cycle-by-cycle variation in the maximum pressure rise, the maximum rate of pressure rise and the maximum rate of heat release at the given equivalence ratios. Mixture stratification and fast flame propagation with the aid of turbulence produced by the high speed fuel jet are considered to be responsible for these behaviours. Cycle-by-cycle variations in combustion durations and combustion products present higher magnitudes than those of maximum pressure rise and maximum rate of heat release. Cycle-by-cycle variations of CO and unburned CH4 show an interdependence with the variation of the late combustion duration, and the variation of NO x shows an interdependence with the variation of the rapid combustion duration. Cycle-by-cycle variations are found to be insensitive to the equivalence ratios in CNG DI combustion.


Author(s):  
Constantin Pana ◽  
Maria Alexandra Ivan ◽  
Alexandru Cernat ◽  
Niculae Negurescu ◽  
Cristian Nuțu ◽  
...  

This chapter presents aspects of hydrogen use in comfort systems and thermal machines in order to improve performance and to reduce pollution emissions. Hydrogen energy is clean, and its use leads to a reduction of CO2 emissions into the atmosphere. It represents an alternative to traditional fuels, oil, coal, and gas. The use of hydrogen preserves traditional fuel resources. In the field of comfort, the energy obtained from hydrogen is applicable in the heating and air conditioning of spaces, in the production of electricity necessary to create light comfort. The use of hydrogen in boilers leads to the reduction of pollutant emissions. Hydrogen fuelling systems were designed for different experimental thermal machines, designed by authors from spark-ignition engine and compression ignition engine. The characteristic combustion parameters, like maximum pressure, the maximum rate of pressure rise, efficiency, and pollutant emissions for hydrogen fuelling are presented and analyzed.


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