Improvement of Main Baum Jig into VARI-WAVE Type in Ikeshima Colliery

摘要

In order to increase the capacity and to obtainhigher accuracy of separation the main Baum jig in Ikeshimacolliery has been improved into a VARI-WAVE jig, which hasbeen developed to create a desired wave pattern of pulsation.The existing rotary valve of mechanical type on each cell wasreplaced by an exhaust valve and two inlet valves to admit highand low pressure air. Each valve is driven by an air cylinder andan electromagnetic valve which is periodically operated by acontroller. A set of new blower and air duct have been installedfor a high pressure air supply while the existing system has beenutilized for a low pressure air supply. The existing refuse ejectorof gate type has been replaced by that of star wheel type whosespeed is controlled automatically. One of the most distinctadvantages offered by the improvement is an easy and promptcontrol of the pulsation. The wave height, the wave pattern andthe period of pulsation became very easy to change and adjust. Ithas been found that the wave pattern of pulsation has anoticeable effect on the mobility and the separation of theparticles. After the improvement the jig is operating successfully.The float-and-sink analysis of the product of the first bucketelevator shows that it can be expected to recover about 10,000tons of steam coal a year.