Study on the explosibility of dusts in paddy drying, processing and storage facilities

Abstract

Dust accummulation in paddy drying, processing, and storage facilities was examined, and explosibilities of the dust collected in these facilities were tested by means of the Hartmann apparatus.
The dust deposited was 100-500 (g/m²) in the examined facilities and dust cloud was expected to be easily formed. The predominant substance in the dust was rice hairs (pubescences).
Chemical and phisical properties of the dust were as follows: moisture content 9-12% d. b., volatile matter content 38-50, ash 35-54, fixed carbon 8-14% moisture free basis, median particle diameter 20-60μm, calolific value 1930-2450cal/g.
In the explosibility tests, even with the undried dusts (moisture content 9-14%), all the dusts tested exploded. It can be thought that the danger of explosion is reat. The dried dusts through 200 mesh sieve indicated maximum explosion pressure of 4.3-6.1 (kg/cm²) and maximum pressure rise of 73-141 (kg/cm²·sec).