the other end of the trough the intermediate wall 39b and end wall 39d form a compartment 39c the intermediate wall 39b does not extend all the way to the bottom of the trough thus providing a passage for flow of the dye between the compartment 39c and the central part of the trough a removable open ended overflow stand pipe 35p is positioned over a machined orifice and outlet pipe 35x in the bottom of the compartment 39c making a tight joint upon lifting of the stand pipe the dye of the trough may be drained but while the stand pipe is standing in place the level of dye in the trough is maintained at not more than the height of the stand pipe dye may be continuously fed into the trough and circulated in any suitable conventional fashion although the trough and roll unit above described is horizontally removable it will be understood that the units could be individually vertically removable after the final dye assembly has been passed by the yarn sheet goes into a conventional drying chamber 115 wherein the yarns are thoroughly dried as an alternative instead of deferring setting of the dye the yarn may be carried on into a conventional steam chamber not shown between the dyeing stage and the drying chamber wherein the steam causes the dye to penetrate into the fibers of the yarns and.