The work is devoted to the activation of metal powder mixtures suitable for use in flameless food heaters. Four activated powders have been manufactured starting from the reference material using a standard technique. Activated powders exhibited a significant increment of the reactivity for the reference mixture. Experimental tests were carried out to characterize the resulting composites in terms of the combustion rate. The oxidation reaction at a low heating rate was monitored using a SEIKO EXTAR II thermal analysis machine and its tests were carried out at open air in temperature range starting from room temperature up to 1150 °C at the heating rate of 10 °C/min. Powders activated by mechanical activations and the initial mixture of materials were characterized in terms of apparent density, absorbed surfactant with the mass of sizing, i.e. granulometry, oxidation properties at a low heating rate. With increase the grinding time, the color of the powder switches to dark tones. Powder granulometry was performed on a MALVERN laser granulometer MASTERSIZER 2000 using dry block SCIROCCO. Three measurements for each sample were performed and the results were averaged. The tests were recorded and processed by digital technology to make the combustion rate of the powders, also the experimental setup used for investigations was presented. The sample AlS-AlF _MnO2 _SiO-150 is characterized by the lowest metal content, and by the most regular combustion propagation. The powder AlS-AlF_MnO2_SiO-50 features the highest metal content, but the less regular combustion propagation. The use of mechanical activation allows increasing the number of nanoscale materials, which contributes to the synthesis of highly effective flameless food heaters.

Effect of mechanical activation on the reactivity of composites for flameless heaters

Galfetti L.;
2020-01-01

Abstract

The work is devoted to the activation of metal powder mixtures suitable for use in flameless food heaters. Four activated powders have been manufactured starting from the reference material using a standard technique. Activated powders exhibited a significant increment of the reactivity for the reference mixture. Experimental tests were carried out to characterize the resulting composites in terms of the combustion rate. The oxidation reaction at a low heating rate was monitored using a SEIKO EXTAR II thermal analysis machine and its tests were carried out at open air in temperature range starting from room temperature up to 1150 °C at the heating rate of 10 °C/min. Powders activated by mechanical activations and the initial mixture of materials were characterized in terms of apparent density, absorbed surfactant with the mass of sizing, i.e. granulometry, oxidation properties at a low heating rate. With increase the grinding time, the color of the powder switches to dark tones. Powder granulometry was performed on a MALVERN laser granulometer MASTERSIZER 2000 using dry block SCIROCCO. Three measurements for each sample were performed and the results were averaged. The tests were recorded and processed by digital technology to make the combustion rate of the powders, also the experimental setup used for investigations was presented. The sample AlS-AlF _MnO2 _SiO-150 is characterized by the lowest metal content, and by the most regular combustion propagation. The powder AlS-AlF_MnO2_SiO-50 features the highest metal content, but the less regular combustion propagation. The use of mechanical activation allows increasing the number of nanoscale materials, which contributes to the synthesis of highly effective flameless food heaters.
2020
Exothermic reaction
Flameless heaters
Heat transfer sources
Mechanochemical activation
Powder mixtures
Self-heating
File in questo prodotto:
File Dimensione Formato  
KALIA01-20.pdf

accesso aperto

Descrizione: Paper Open Access
: Publisher’s version
Dimensione 878.23 kB
Formato Adobe PDF
878.23 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1146577
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 2
social impact