Computer for fractionation calculations

THE PETROLEUM and natural gas industries utilize fractionating columns to separate hydrocarbons of high volatility from hydrocarbons of low volatility. Each column, or tower, is a type of equipment which permits a liquid stream to cascade down over a series of trays or plates and allows a vapor stream to bubble up through the plates countercurrent to the liquid stream. The feed stream (containing several components such as methane, ethane, butane, propane, and so forth) enters one of the chambers part way up the column. Each of the components of the feed is present in varying amounts in the liquid stream falling from a given plate and the vapor stream rising from a given plate. The relative amounts of the several components in a given stream depend upon several factors including the temperature and pressure of the stream and the relative amounts of the liquid and vapor components in the streams approaching the plate. Within the column as a whole, large percentages of the less volatile components fall in liquid form toward the bottom, while large percentages of the more volatile components rise in vapor form toward the top. The liquid and vapor flows within the tower are maintained by supplying heat to the bottom of the column and removing it from the top.