Briquetting process

摘要

A process and system for briquetting particulate matter such as moisture-containing bituminous and sub-bituminous coal includes partially drying and feeding the particulate matter to a briquetting apparatus under conditions such that water vapor is released from the particulate matter during feeding. The released water vapor substantially displaces or prevents the ingress of a large proportion of other gaseous components from the atmosphere surrounding an/or intermixed with the particulate matter. The particulate matter is surrounded by and intermixed with a gaseous component containing 70% to 100% by volume of water vapor where it enters the briquetting apparatus, such that when the particulate matter is compressed, the water vapor liquefies and the pressure buildup in the thus-formed briquettes is minimized. This reduction in the pressure buildup reduces blow-back of gases as the coal fines are formed into briquettes.

主权项

1. A process for briquetting particulate bituminous matter containing moisture, comprising:
partially drying the particulate bituminous matter under process conditions including a temperature of above 100° C. and for a period which will raise the temperature of the particulate bituminous matter to above 90° C. and decrease the total moisture content of the particulate bituminous matter to between 1% and 10% by weight of the particulate bituminous matter; maintaining the temperature of the partially dried particulate bituminous matter above 80° C. whilst feeding the particulate bituminous matter towards a briquette forming part of a briquetting apparatus along a feed path from which the ingress of ambient air is excluded, thereby causing water vapor driven from the particulate bituminous matter to substantially displace ambient air and other gasses from the interstices between the particles of the particulate bituminous matter as the particulate bituminous matter moves towards the briquette forming part of the briquetting apparatus; feeding the partially dried particulate bituminous matter into the briquette forming part of the briquetting apparatus, wherein feeding the partially dried particulate bituminous matter into the briquette forming part of the briquetting apparatus comprises using at least one precompaction auger, and applying a back pressure to said particulate bituminous matter using said precompaction auger and precompacted particulate bituminous matter to define a tortuous path to assist in further reducing blow-back of gases through the particulate bituminous matter being fed to the briquetting forming part of the briquetting apparatus; and briquetting the particulate bituminous matter in the briquette forming part of the briquetting apparatus at a pressure which is sufficient to cause the entrained water vapor to condense, wherein the briquette forming part of the briquetting apparatus includes a pair of rollers through which the particulate bituminous matter passes, at least one of the rollers having pockets formed therein for assisting in defining the shape of the briquettes, and the process further comprises rotating the pair of rollers at peripheral roll speeds from 113.1 m/min to 188.5 m/min and applying a loading with the rollers within a range of 115 kN/cm to 150 kN/cm.