| 摘要 |
<p>To avoid deposits on the restrictor that channels extractant into a collector (1901), a heated capillary tube (1900) pressure release restrictor has a thermally insulated outlet end in a collecting trap (1908) substantially colder than the capillary tube (1900). The restrictor is heated between the insulation (1906) and the capillary tube (1908) by Joulean heating. The solvent in the trap (1908) is at a pressure of 5 to 200 psi above atmospheric pressure. The thermal resistance of the insulation (1906) is selected to reduce the heat added to the extractant to a minimum, to keep the extractant from freezing, and to reduce partitioning of the extract and extractant. It has a thermal conductivity no greater than 60 BTU's per hour, per square foot, per inch for a one degree Fahrenheit difference.</p> |
