Patent ID: 7555918

Claim:
The method of adding heat to refrigerated rich liquid that accumulates in a reservoir in a distillation column, to prevent the column from flooding, that includes the steps a) sensing a rise in rich liquid level to predetermined level in the reservoir, a) removing rich liquid from the reservoir in response to said sensing, to flow to vaporizer apparatus, c) adding heat to the removed rich liquid and converting the removed rich liquid into gas, in said vaporizer apparatus, d) returning said gas to the distillation column, e) utilizing heat from the returned gas in the column to remove excess refrigeration from the rich liquid remaining in the column, thereby stabilizing the column against flooding, f) and including allowing said rich liquid remaining in the column to leave the reservoir to be sub-cooled and flashed to a lower pressure and lower temperature, and then heating the flow in vapor state for flow through an expansion turbine, to be cooled as work is extracted from the turbine.