Relationship between the measured pressures in different parts of an 18.5 m(3) silo during maize starch explosions tests

Abstract

Agricultural materials dusts, such as maize starch, can generate explosions when is divided in fine particles and suspended in the air. To the explosion occur it is necessary an ignition source which may be a spark, a heating of a mechanism or a part of the structure, or the spontaneous combustion generated by biological processes (fermentation, respiration, etc.). This leads to the need to protect against explosions the structures where these materials are stored, such as silos. One of the most common methods of protection is vent panels located on the walls and the roof. There are numerous studies on dust explosions in agricultural products, but few that have used full scale silos, such as the work presented in this paper. In this work pressures were measured within an 18.5 m(3) silo with a 0.52 m(2) vent panel, wherein corn starch explosions were performed. For this, pressure sensors were placed at four points of the silo wall: near the panel, at the bottom, in the first ferrule and the third (of a total of four ferrules). It was also detected the moment of the panel opening; to know how was influencing the pressures distribution and values. As a consequence, this is the first time that a comparative study of the evolution of these pressures throughout the development of the explosion in a full scale silo is published, which will help to understand the phenomenon and improve the security procedures.