| 摘要 |
<p>PURPOSE:To recover liq. nitrogen for cold-compensation as N2 gas at ordinary temp. and press., by cooling high-press. N2 gas by heat exchange with liq. nitrogen obtained from an air separation plant. CONSTITUTION:Raw material gas delivered through a pipe 8 and cooled in a heat exchanger 1 is fed to a nitrogen-washing tower 2. High press. N2 gas at ordinary temp. is fed through a pipe 12 to a heat exchanger 3, where it is liquiefied. The liquefied N2 is sent through pipes 13, 14 to the top of the N2-washing tower 2, where it is used for washing the raw material gas. After expanded by a expansion valve 6 to nearly ordinary press., the liq. N2 exchanges heat with the high press. N2 gas in a heat exchanger 3. Refined N2 gas drawn out of the top of the tower 2 joins the liq. N2 which runs through a pipe 15 and a control valve 4, and exchange heat with the raw material gas in the heat exchanger 1. Supercooled liq. N2, which is to be used for cold-compensation and delivered from a rectifier of an air separation plant, is expanded to nearly atmospheric press. while passing through a pipe 18 and an expansion valve 7, and is recovered through a pipe 19 as ordinary-temp. N2 gas after cooling and liquefying the high press. N2 gas by exchange of heat in the heat exchanger 3.</p> |
