초록 ▼

A cartridge heater for mounting in the bore hole of a device to heat the device, having an improved release coating to facilitate the removal of the cartridge heater from the bore hole subsequent to operation at elevated temperatures, wherein the release coating is a fast-drying, graphite-based soli

A cartridge heater for mounting in the bore hole of a device to heat the device, having an improved release coating to facilitate the removal of the cartridge heater from the bore hole subsequent to operation at elevated temperatures, wherein the release coating is a fast-drying, graphite-based solid film lubricant that bonds to the heater.

대표청구항 ▼

What is claimed is: 1. A cartridge heater for mounting in a bore hole of a device to heat the device, said heater including an outer metal sheath capable of withstanding high temperatures, and completely cured release means on the sheath before use for facilitating removal of the heater from a bore

What is claimed is: 1. A cartridge heater for mounting in a bore hole of a device to heat the device, said heater including an outer metal sheath capable of withstanding high temperatures, and completely cured release means on the sheath before use for facilitating removal of the heater from a bore hole subsequent to operation of the heater, wherein said release means remains substantially intact upon removal of the heater from said device, said release means comprising a cured coating of a fast-drying graphite-based solid film lubricant with an organo-metallic binder system in a solvent carrier, wherein said lubricant provides a low coefficient of friction on the sheath and thermal stability for operating in high temperature conditions. 2. The cartridge heater of claim 1, wherein the coating is in liquid form when applied to the outer sheath after the sheath has been prepared by being degreased, grit-blasted, and subjected to removal of any residual blast media, and wherein said coating after application to said sheath is quick drying and air dries to the touch in less than five minutes in an ambient of 60 to 100째 F. and a relative humidity of at least fifty percent, and fully cures within six hours in said ambient. 3. The cartridge heater of claim 1, wherein said metal sheath is a steel alloy. 4. The cartridge heater of claim 1, wherein said metal sheath is a titanium alloy. 5. The cartridge heater of claim 1, wherein said metal sheath is a stainless steel. 6. The method of preparing and coating a cartridge heater having a steel alloy sheath for use in a bore hole of a device with a liquid solid film lubricant that is graphite based with an organo-metallic binder system in a solvent carrier to prevent the heater from seizing in the bore hole after use at elevated temperatures, said lubricant on said heater being dry to touch in a few minutes after application and cured in a few hours when in an ambient of 60 to 100째 F. and a relative humidity of about 50 percent and capable of maintaining thermal stability to remain substantially intact after usage, said step of preparation including: degreasing the sheath, grit-blasting the sheath, and cleaning the sheath to remove any residual blast media. 7. The method of claim 6, wherein the step of coating includes spraying the lubricant onto said sheath of the heater. 8. The method of claim 6, wherein the step of coating includes dipping the heater into a bath of lubricant and withdrawing the heater from the bath. 9. The method of claim 6, wherein the step of coating includes dipping the heater into a bath of lubricant and withdrawing the heater from the bath, and spinning the heater to remove excess lubricant. 10. The method of claim 6, wherein the step of curing includes placing the coated heater in an atmosphere of 60 to 100째 F. and a relative humidity of at least 50 percent for about six hours. 11. The method of claim 6, wherein the lubricant coating dries to touch in a few minutes in an ambient of about 60 to 100째 F. and a relative humidity of at least fifty percent, and fully cures within six hours in substantially the same ambient. 12. The method of claim 6, which method further includes passivating the sheath of the heater following said step of cleaning the sheath. 13. The combination of a cartridge heater mounted in a bore hole of a device for heating the device, wherein said cartridge heater includes an outer metal sheath, and a release coating on said metal sheath cured prior to mounting in said bore hole to facilitate removal of the cartridge from the bore hole following the operation of the cartridge at an elevated temperature, the improvement in the release coating which comprises a solid film lubricant that is air-curable at ambient temperature to touch within about five minutes, and substantially completely cured within about six hours after application thereof to the sheath in an ambient of 60 to 100째 F. and a relative humidity of at least fifty percent, said lubricant being graphite based with an inorganic binder system in a solvent carrier. 14. The combination as in claim 13, wherein the sheath is a steel alloy that can withstand temperatures up to about 1600째 F.