CO.sub.2 cleaning system and method
AssigneeFord Motor Company
InventorLakhi N. Goenka
Life of this patent
Estimating the term…
Abstract
A nozzle expels liquid CO.sub.2 through an orifice for converting the liquid into CO.sub.2 snow. The nozzle is contained within an elongated cavity within a body which in turn is coupled to an exhaust nozzle for directing the CO.sub.2 snow toward a workpiece. A mixing device is provided for receiving and mixing pressurized air at ambient temperature with liquid nitrogen for precooling the air and then directing the resulting mixture of gases into the cavity and toward the nozzle. In this manner, the precooled shop air will enhance the efficiency of the conversion of the liquid CO.sub.2 into CO.sub.2 snow particles.
Claims17
An apparatus for cleaning a workpiece with abrasive CO.sub.2 snow, comprising in combination:
- a nozzle for receiving and expelling liquid CO.sub.2 through an orifice sized for directly converting the liquid CO.sub.2 into CO.sub.2 snow,
- a body defining a cavity therein, with said nozzle being coupled to said body for ejecting the CO.sub.2 snow into said cavity,
- an exhaust nozzle coupled to said body and said cavity therein for directing the CO.sub.2 snow toward the workpiece, and
- mixing means for receiving and mixing pressurized shop air at ambient temperature with liquid N.sub.2 in portions for precooling the shop air to at least 0 degrees F., said mixing means being coupled to said body for directing the cooled shop air into said cavity for cooling the area adjacent to said orifice in said nozzle and for exhausting the CO.sub.2 through said exhaust nozzle under pressure, whereby the cooled mixture of shop air and gaseous N.sub.2 enhances the efficiency of the direct conversion of the liquid CO.sub.2 into CO.sub.2 snow particles.
A method for cleaning a workpiece with abrasive CO.sub.2 snow, comprising the steps of:
- receiving CO.sub.2 in a liquid form at a first pressure and temperature,
- passing the liquid CO.sub.2 through an orifice in a nozzle for directly converting at least a portion of the liquid CO.sub.2 into CO.sub.2 snow,
- collecting the CO.sub.2 now within an elongated cavity for enhancing the coagulation of the CO.sub.2 snow into snow particles and then passing the CO.sub.2 snow and snow particles through an exhaust nozzle having a contour for directing the flow toward the workpiece,
- mixing shop air, at ambient temperature and a pressure of less than 100 psi, with liquid N.sub.2 for cooling the resulting gaseous mixture, and
- injecting the cooled mixture of shop air and N.sub.2 into the elongated cavity adjacent the nozzle for improving the conversion efficiency of the liquid CO.sub.2 into snow particles by decreasing the temperature adjacent to the nozzle, and for exhausting the snow particles under pressure through said exhaust nozzle.
An apparatus for cleaning a workpiece with abrasive CO.sub.2 snow, comprising in combination:
- a nozzle for receiving and expelling liquid CO.sub.2 through an orifice sized for directly converting the liquid CO.sub.2 into CO.sub.2 snow,
- a body defining an elongated cavity therein, with said nozzle being coupled to said body for ejecting the CO.sub.2 snow into said elongated cavity,
- an exhaust nozzle coupled into said elongated cavity of said body for directing the CO.sub.2 snow from said elongated cavity toward the workpiece, and
- first means coupled to said body for receiving and directing pressurized air at a known temperature into said elongated cavity in the area adjacent to said orifice in said nozzle for enhancing the conversion efficiency of generating the CO.sub.2 snow, for enhancing the coagulation of the CO.sub.2 snow into larger CO.sub.2 snow particles within said elongated cavity, and for exhausting under pressure the CO.sub.2 snow and particles out through said exhaust nozzle,
- whereby the pressurized air enhances the efficiency of generating the CO.sub.2 snow particles.
A method for cleaning a workpiece with abrasive CO.sub.2 snow, comprising the steps of:
- receiving liquid CO.sub.2 at a first pressure and temperature,
- passing the liquid CO.sub.2 through an orifice in a nozzle for directly converting at least a portion of the CO.sub.2 from the liquid phase into CO.sub.2 snow,
- coagulating the CO.sub.2 snow within an elongated cavity to form CO.sub.2 snow particles,
- passing the CO.sub.2 snow and CO.sub.2 snow particles through an exhaust nozzle having a contour for directing the flow toward the workpiece,
- injecting shop air into the elongated cavity adjacent the nozzle for agitating the CO.sub.2 snow to enhance coagulation of the CO.sub.2 snow particles, and for exhausting under pressure the CO.sub.2 snow particles through the exhaust nozzle.
Dependencies are inferred from the claim text.