초록 ▼

An apparatus and method for cleaning a workpiece with abrasive CO2 snow operates with a nozzle for creating and expelling the snow. The nozzle includes an upstream section defined by a first contour for receiving CO2 in a gaseous form. The nozzle also includes a downstream section for directing the

An apparatus and method for cleaning a workpiece with abrasive CO2 snow operates with a nozzle for creating and expelling the snow. The nozzle includes an upstream section defined by a first contour for receiving CO2 in a gaseous form. The nozzle also includes a downstream section for directing the flow of the CO2 and the snow toward the workpiece, with the downstream section having a second contour optimized for supersonic flow of the CO2. The nozzle includes a throat section, interposed between the upstream and downstream sections, for changing the CO2 from the gaseous phase to an intermediate mixture of CO2 gas, liquid and snow within the downstream section at a speed of at least Mach 1.1. A turbulence cavity section is interposed between the throat section and the downstream section for inducing both turbulence within the CO2 gas flowing therethrough, thereby increasing the nucleation and agglomeration of the CO2 within a snow zone defined within the downstream section. The throat, upstream, turbulence cavity and downstream sections of the nozzle may be manufactured from silicon micromachined surfaces.

대표청구항 ▼

An apparatus for cleaning a workpiece with abrasive CO2 snow, comprising a nozzle for creating and expelling the CO2 snow, comprising: an upstream section for receiving CO2 gas at a first pressure, said upstream section having a first contour optimized for subsonic flow of the CO2, a downstream sect

An apparatus for cleaning a workpiece with abrasive CO2 snow, comprising a nozzle for creating and expelling the CO2 snow, comprising: an upstream section for receiving CO2 gas at a first pressure, said upstream section having a first contour optimized for subsonic flow of the CO2, a downstream section for directing the flow of the CO2 and the CO2 snow toward the workpiece, said downstream section having a second contour for developing supersonic flow of the CO2, a throat section, coupled between and for cooperating with said upstream and downstream sections, for changing at least a portion of the CO2 flowing therethrough from the gaseous phase, into CO2 snow within said downstream section at a speed of at least Mach 1.1, and a turbulence cavity section, interposed between said throat section and said downstream section, comprising surfaces for introducing both shear and vortex turbulence within the flow of gaseous CO2 flowing adjacent thereto and for increasing the nucleation of the CO2 snow within said downstream section, whereby the additional turbulence introduced into the CO2 flowing within said turbulence cavity improves the conversion efficiency of the CO2 gas into CO2 snow particles.