Method of determining flood points of packed columns

A method of determining a flood point of a packed column for liquids and vapors of variable physical properties comprising:

• (a) providing a reference data set of two-phase pressure drop values as a function of gas and liquid flow rates for a reference liquid and a reference gas at several liquid flow rates through a reference packed column;
• (b) converting the reference data set to dimensionless two-phase pressure drop values as a function of the density of the liquid phase of a subject packed column thereby making the two-phase pressure drop values at flood inversely proportional to the density of the liquid phase;
• (c) providing a known flood point value for one liquid flow rate in the reference data set;
• (d) setting working flood point values for higher liquid flow rates at values lower than the known flood point value;
• (e) setting working flood point values for lower liquid flow rates at values higher than the known flood point value;
• (f) expressing gas flow rates for liquid flow rates as fractions of the working flood point value for each respective liquid flow rate in the reference data set;
• and
• (g) at a constant two-phase pressure drop value:
• i) from the fractions of the working flood point value calculating an average fractional flood point value for the liquid flow rates;
• and
• ii) minimizing the standard deviation between the fractional flood point value at different liquid flow rates and the calculated average fractional flood point value by repeating steps (c)-(g) over reference two-phase pressure drop and liquid flow rate data,
• resulting in determining a flood point of the subject packed column at any liquid flow rate and at any liquid density.