Vapor/liquid contact column structure

A vapor-and-liquid contact structure for distillation, fractionation, rectification, absorption, and the refining, in a column, of various liquid materials such as petroleum, chemical, and alcohol solutions wherein provision is made for the inclusion of vertically-spaced bubble plate chambers, having respective liquid and vapor contact devices, to accommodate contact of counter-current flows of reflux liquid and vapors. A downcomer, including slanted ramps, is disposed outside of the vapor conduit-defining interior, and defines an elongate downcomer structure for liquid flow. Accordingly, descending reflux liquid flow is kept outside of primary vapor flow, with secondary vapor evolving from descending reflux being conducted circuitously back into the primary vapor flow for ascent to the next-above contact device. Plate efficiency is enhanced through maximum plate-area effective use and unidirectional liquid-flow over such plates. Column sections are constructed in essentially identical modules which can be stacked and secured together to reduce fabrication and engineering costs.