An investigation into outstanding problems concerning coal storage in and extraction from silos, including those of gas accumulation and spontaneous ignition
Two methods to avoid blockages occurring in flat bottomed silos have been investigated. The first involved installing a large area rod gate valve, the second a mass flow cone. Both methods were successful. Two test rigs were designed, built and tested to investigate the spontaneous heating of coal in enclosed bulk storage, and to develop methods to control and quench such incidents. Two ventilation systems to remove methane gas from the headspaces of silos have been tested, one Venturi based, the other fan based. The latter is more effective but may have higher maintenance costs and inherent risk of causing an explosion. An earlier study concerned the effects of a rotating sweep auger on the pressures exerted on the fabric of a silo during operation. The pressure data from this study were analysed further, and it is suggested that cohesive domes form and collapse in a cyclic fashion as the auger rotates, causing displacement of the wall by up to 1.8 mm. This may explain some of the cracking found in certain silos.
Bibliographic Reference: EUR 13049 EN (1990) 93 pp., MF, ECU 4, blow-up copy ECU 12.50
Record Number: 199110089 / Last updated on: 1994-12-02
Original language: en
Available languages: en