METHODS FOR COOLING OF ABRASIVE GRINDING USING CARBON DIOXIDE

Abstract

A method for cooling a workpiece that is typically metallic in nature that is undergoing a grinding operation by spraying liquid carbon dioxide at the workpiece. The liquid carbon dioxide is directed at the workpiece and form a carbon dioxide snow which will provide cooling and improve the efficiency of the grinding operation. Alternatively, the liquid carbon dioxide can be sprayed onto the back surface of the abrasive belt which will also provide the requisite cooling but help the belt from delaminating.

Claims

1. A method for cooling a workpiece during a grinding operation of the workpiece comprising spraying liquid carbon dioxide onto the workpiece.

2. The method as claimed in claim 1 wherein the liquid carbon dioxide is fed from a source of liquid carbon dioxide through a nozzle.

3. The method as claimed in claim 2 wherein the source of liquid carbon dioxide is selected from the group comprising liquid siphon tube cylinders, dewars and bulk supply tanks.

4. The method as claimed in claim 1 wherein the liquid carbon dioxide is sprayed at a temperature and a pressure above the triple point of carbon dioxide of −56.6° C. and 5.11 atmospheres.

5. The method as claimed in claim 2 wherein the liquid carbon dioxide expands upon contact with an atmosphere surrounding the workpiece thereby forming carbon dioxide snow.

6. The method as claimed in claim 1 wherein the workpieces are metallic.

7. The method as claimed in claim 6 wherein the metallic workpieces are stainless steel.

8. The method as claimed in claim 1 wherein the liquid carbon dioxide is sprayed during the entire grinding operation.

9. The method as claimed in claim 1 wherein the cooling of the workpiece results in reduction of seven degrees in temperature during the grinding operation.

10. A method for cooling a workpiece during a grinding operation of the workpiece wherein the grinding operation is performed using an abrasive belt comprising spraying liquid carbon dioxide onto a back surface of the abrasive belt.

11. The method as claimed in claim 10 wherein the abrasive belt is held stationary.

12. The method as claimed in claim 10 wherein the liquid carbon dioxide is fed from a source of liquid carbon dioxide through a nozzle.

13. The method as claimed in claim 12 wherein the source of liquid carbon dioxide is selected from the group comprising liquid siphon tube cylinders, dewars and bulk supply tanks.

14. The method as claimed in claim 10 wherein the liquid carbon dioxide is sprayed at a temperature and a pressure above the triple point of carbon dioxide of −56.6° C. and 5.11 atmospheres.

15. The method as claimed in claim 14 wherein the liquid carbon dioxide expands upon contact with an atmosphere surrounding the back surface of the abrasive belt thereby forming carbon dioxide snow.

16. The method as claimed in claim 10 wherein the workpieces are metallic.

17. The method as claimed in claim 16 wherein the metallic workpieces are stainless steel.

18. The method as claimed in claim 10 wherein the liquid carbon dioxide is sprayed during the entire grinding operation.

19. The method as claimed in claim 10 wherein the cooling of the workpiece results in reduction of seven degrees in temperature during the grinding operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0012] The use of the liquid carbon dioxide for cooling of the workpiece or the abrasive belt was tested by placing a nozzle two inches from the interface between the workpiece and the abrasive grinding surface of the belt. The liquid carbon dioxide was sprayed for the duration of the grinding time.

[0013] The temperature of the workpiece, which comprised 304 Stainless Steel, was measured after a control grind during which no coolant or carbon dioxide was used. The temperature of the workpiece following this control test was 97° F. (36.1° C.). During the operation when liquid carbon dioxide snow was directed at the workpiece the temperature was 90° F. (32.2° C.). This 7 degree difference in temperature is significant as it ensures a more efficient grinding operation without the difficulties that a liquid coolant or no coolant at all would encounter.

[0014] Further, the largest reduction in temperature when compared to the control was observed in the spark shower. This reduction was almost 100° F. (37.7° C.). This was also visibly apparent as the spark shower with no liquid carbon dioxide spray was much brighter while the spark shower with the liquid carbon dioxide spray was a duller color indicating that significant heat was removed from the process.

[0015] While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of the invention will be obvious to those skilled in the art. The appended claims in this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.