Adaptive R744 minimum quantity cooling lubrication system
This application presents a method and apparatus for cooling a through-ported cutting tool with a source of liquid CO 2 with a compressed air line with a compressed air inlet and multiple CO 2 injection capillary segments; the capillary segments interconnect to the same source of liquid CO 2 and can have high pressure valves and throttles; the throttles have different sizes; a first capillary ends near the cutting tool; the second capillary ends near the compressed air inlet. Using a particular sequence of opening or closing the valves to the liquid CO 2 to the capillaries, mixing with the compressed air provides and recycling the residual CO 2 , this invention provides for uniform and controlled cooling of the cutting tool within a certain temperature range.
1. An apparatus for cooling a through-ported cutting tool, which has a through-port diameter, with a source of liquid CO 2 comprising:
a compressed air line, which has a compressed air inlet and establishes a flow of compressed air to the cutting tool, and the compressed air line has a first CO 2 injection capillary segment and a second CO 2 injection capillary segment;
the first and the second CO 2 injection capillary segments are interconnected to the same source of liquid CO 2 ;
the first CO 2 injection capillary segment has a first high pressure valve, and the second CO 2 injection capillary segment has a second high pressure valve, and the source of liquid CO 2 has a third high pressure valve;
the first CO 2 injection capillary segment has a first throttle and the second CO 2 injection capillary segment has a second throttle;
the first throttle is smaller than the second throttle;
the first CO 2 injection capillary segment terminates near the cutting tool;
the second CO 2 injection capillary segment terminates near the compressed air inlet;
whereby the third valve and first valve are opened, and an amount of liquid CO 2 , which corresponds to the diameter of the through-port of the cutting tool, charges the first CO 2 injection capillary segment with liquid CO 2 at a predetermined charging pressure;
the third valve is closed, and the liquid CO 2 in the first CO 2 injection capillary segment is mixed into the compressed air near the cutting tool for a predetermined period of time and to predetermined recycle pressure to form a first cooling fluid;
the second valve is opened, and residual CO 2 in the first CO 2 injection capillary segment flows through the second CO 2 injection capillary segment, into the compressed air and near the compressed air inlet to form a second cooling fluid;
Flowing said first and the second cooling fluids through said cutting tool; and
the cutting tool is maintained within a certain temperature range.
2. The apparatus of claim 1 wherein said compressed air pressure is between 30 psi and 500 psi.
3. The apparatus of claim 1 wherein said compressed air flows between 0.5 and 20 scfm.
4. The apparatus of claim 1 wherein said liquid CO 2 is injected in the first CO 2 injection capillary segment from a charging pressure of between 900 and 5000 psi and to a recycle pressure of between 400 and 750 psi.
5. The apparatus of claim 4 wherein said liquid CO 2 is injected into the first CO 2 injection capillary segment at a flowrate of between 0.1 lbs./hour and 20 lbs./hour.
6. The apparatus of claim 1 wherein said liquid CO 2 is injected into the second CO 2 injection capillary segment from a pressure of between 500 and 750 psi and to a pressure, which is equal to the compressed air pressure.
7. The apparatus of claim 1 wherein a small amount of liquid lubricant is injected into the second cooling fluid.
8. The apparatus of claim 7 wherein said liquid lubricant comprises synthetic oil, semi-synthetic oil, mineral oil, bio-based oil, polyalkylene glycol, polyolester or alcohol.
9. The apparatus of claim 7 wherein said liquid lubricant is injected into the second cooling fluid at a flowrate of between 10 ml/hour and 250 ml/hour.
10. The apparatus of claim 8 wherein said liquid lubricant is a fractional solute of a volatile carrier solvent to form a dilute liquid lubricant fluid.
11. The apparatus of claim 10 wherein said volatile carrier solvent comprises a cyclic volatile methyl siloxane, alcohol, ketone or alkene.
12. The apparatus of claim 7 wherein said liquid lubricant is co-injected and mixed with the second cooling fluid using a telescoping lance.
13. The apparatus of claim 1 is controlled automatically using a PLC, digital timers or pressure switches.
14. The apparatus of claim 1 is controlled using cutting force data.
15. The apparatus of claim 1 wherein the second throttle is adjustable.
16. An apparatus for cooling a through-ported cutting tool, which has a through-port diameter, with a source of liquid CO 2 comprising:
a compressed air line, which has a compressed air inlet and establishes a flow of compressed air to the cutting tool, and the compressed air line has a first CO 2 injection capillary segment and a second CO 2 injection capillary segment;
the first and the second CO 2 injection capillary segments are interconnected to the same source of liquid CO 2 ;
the first CO 2 injection capillary segment has a first high pressure valve, and the second CO 2 injection capillary segment has a second high pressure valve, and the source of liquid CO 2 has a third high pressure valve;
the first CO 2 injection capillary segment has a first throttle, and the second CO 2 injection capillary segment has a second throttle;
the first throttle is smaller than the second throttle;
the first CO 2 injection capillary segment terminates near the cutting tool;
the second CO 2 injection capillary segment terminates near the compressed air inlet;
whereby the third valve and first valve are opened, and an amount of liquid CO 2 , which corresponds to the diameter of the through-port of the cutting tool, charges the first CO 2 injection capillary segment with liquid CO 2 at a predetermined charging pressure;
the third valve is closed, and the liquid CO 2 in the first CO 2 injection capillary segment is mixed into the compressed air near the cutting tool for a predetermined period of time and to predetermined recycle pressure to form a first cooling fluid;
the second valve is opened, and residual CO 2 in the first CO 2 injection capillary segment flows through the second CO 2 injection capillary segment, into the compressed air and near the compressed air inlet to form a second cooling fluid;
the first, second, and third valves are controlled using digital timers;
the second throttle is adjustable;
flowing said first and second cooling fluids through said cutting tool; and
the cutting tool is maintained within a certain temperature range.
17. An apparatus for cooling a through-ported cutting tool, which has a through-port diameter, with a source of liquid CO 2 comprising:
a compressed air line, which has a compressed air inlet and establishes a flow of compressed air to the cutting tool, and the compressed air line has a first CO 2 injection capillary segment and a second CO 2 injection capillary segment;
the first and the second CO 2 injection capillary segments are interconnected to the same source of liquid CO 2 ;
the first CO 2 injection capillary segment has a first high pressure valve, and the second CO 2 injection capillary segment has a second high pressure valve, and the source of liquid CO 2 has a third high pressure valve;
the first CO 2 injection capillary segment has a first throttle, and the second CO 2 injection capillary segment has a second throttle;
the first throttle is smaller than the second throttle;
the first CO 2 injection capillary segment terminates near the cutting tool;
the second CO 2 injection capillary segment terminates near the compressed air inlet;
whereby the third valve and first valve are opened, and an amount of liquid CO 2 charges the first capillary segment;
the third valve is closed, and the liquid CO 2 in the first CO 2 injection capillary segment is mixed into the compressed air and near the cutting tool to form a first cooling fluid;
the second valve is opened, and residual CO 2 in the first capillary segment flows through the second CO 2 injection capillary segment, into the compressed air and near the compressed air inlet to form a second cooling fluid;
Flowing said first and the second cooling fluids through said cutting tool; and
the cutting tool is maintained within a certain temperature range.