| 摘要 |
A process for separating a malleable element having a limited exposed surface area from a member in supporting contact therewith comprises contacting the malleable element with a solubilizing liquid (solvent or reagent) whose sole action is upon the malleable element and periodically applying a predetermined super-atmospheric pressure for a predetermined time and allowing the pressure to return to atmospheric with removal of accumulation of gases until the malleable element is dissolved. The apparatus, Fig. 1 (not shown), may comprise a vessel 21a containing the articles to be treated surrounded by chamber 10a containing an acid reagent, said chamber being in communication with a condensing system 16 and source of pressure through conduit 12. Rods 22 comprising stainless steel hypodermic syringe cannulae surrounding a copper core are placed within 21a which is adapted to be heated by means 11. Conduit 14 containing valve 15 has the condenser 16 attached thereto, to return acid to chamber 10a down line 19 through valve 20. Conduit 18 leads to an abosrber for final removal of acid fumes. In a further embodiment, Fig. 2 (not shown), vessel 21a has imperforate walls and said vessel and chamber are only partially filled with solvent. In operation valves 15 and 20 are closed so that on opening valve 13 the interior of the vessel 11a is placed under pressure a of 16-1000 p.s.i. Having applied the pressure for a period of 1/60 -30 seconds valve 13 is closed for a further period of 1/60 -30 seconds then 15 is opened and vapours pass through 14 to condensing means 16. Valve 20 is opened to allow condensed vapours to return to 10a. The sequence is repeated until the core is removed. Core elements specified are Ca, Al, Ni, soft C steel or a plastics material. An example refers to the removal of core elements from 20 gauge stainless steel tubing of internal diameter 0,023 inches and 1,5 inches long using 65% HNO3. |
