Silicon micromachined CO.sub.2 cleaning nozzle and method
US5545073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1993 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Apr 5, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05B7/14
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An apparatus and method for cleaning a workpiece with abrasive CO.sub.2 snow operates with a nozzle for creating and expelling the snow. The nozzle includes an upstream section for receiving CO.sub.2 in a gaseous form, and having a first contour shaped for subsonic flow of the CO.sub.2. The nozzle also includes a downstream section for directing the flow of the CO.sub.2 and the snow toward the workpiece, with the downstream section having a second contour shaped for supersonic flow of the CO.sub.2. The nozzle includes a throat section, interposed between the upstream and downstream sections, for changing the CO.sub.2 from the gaseous phase along a constant entropy line to a gas and snow mixture within the downstream section at a speed of at least Mach 1.0. In this manner, additional kinetic energy is imparted to the snow by delaying the conversion into the solid phase until the gaseous CO.sub.2 reaches supersonic speeds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.