US 5,366,290 AGranted

High temperature optical probe

AssigneeAmetek, Inc.

InventorsChristopher R. Mayer, Leon Reznikov

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Abstract

A high temperature optical probe for an optical gas temperature sensor includes a support, a generally conical hollow tip, and a joint physically interconnecting the support and the tip. The tip includes as an electromagnetic radiation emitter a sapphire-free ceramic selected from the group consisting of silicon carbide and silicon nitride. An optical lens supported in the tip is removable from the tip for repair and replacement. The joint is of a material and geometry to accommodate the thermal stresses caused by differences in thermal coefficients of expansion between the tip, joint and support, and the mechanical stresses caused by the interaction of the probe and the gas stream during high velocity movement of the gas stream past the tip. The joint sidewall is welded to the support and has a thickness of 0.008-0.012 inch where it overlaps the tip.

Claims15

Dependent claims

An optical probe for a gas temperature sensor for sensing the temperature of a high-temperature, high-velocity gas stream, comprising:

(A) a generally conical hollow tip for insertion into the gas stream formed of a ceramic selected from the group consisting of silicon carbide and silicon nitride to emit electromagnetic radiation at the high temperatures to be sensed, said tip defining a longitudinally-extending tip sidewall;
(B) support means for mounting said tip for interaction with the high-temperature, high-velocity gas stream;
(C) a joint physically interconnecting and spacing apart said support means and said tip, said joint being of a material and geometry to accommodate the thermal stresses caused by differences in thermal coefficients of expansion between said tip, said joint and said support means and the mechanical stresses caused by the interaction of said probe and the gas stream during high velocity movement of the gas stream past said tip, thereby to enable said probe to withstand said stresses said joint being welded to said support means and defining a longitudinally-extending joint sidewall having a portion thereof with a thickness of about 0.008-0.012 inch overlapping and supporting a longitudinally-extending portion of said tip sidewall;
and
(D) optical means, disposed in said tip and responsive to the temperature of the gas stream proximate said tip, for focusing and transmitting electromagnetic radiation emitted from said tip in response to the temperature of the gas stream proximate said tip in order to effect a measurement of the temperature of the gas stream.

2 more elements

An optical probe for a gas temperature sensor for sensing the temperature of a high-temperature, high-velocity gas stream, comprising:

(A) a generally conical hollow tip for insertion into the gas stream formed of a ceramic selected from the group consisting of silicon carbide and silicon nitride to emit electromagnetic radiation at the high temperatures to be sensed, said tip defining a longitudinally-extending tip sidewall, said tip being characterized by a high flexural strength, a high oxidation resistance, a high thermal shock resistance, and a low thermal response time constant;
(B) support means for mounting said tip for interaction with the high-temperature, high-velocity gas stream;
(C) a joint physically interconnecting and spacing apart said support means and said tip, said joint being of a material and geometry to accommodate the thermal stresses caused by differences in thermal coefficients of expansion between said tip, said joint and said support means and the mechanical stresses caused by the interaction of said probe and the gas stream during high velocity movement of the gas stream past said tip, thereby to enable said probe to withstand said stresses, said joint being welded to said support means and defining a longitudinally-extending joint sidewall having a portion thereof with a thickness of about 0.008-0.012 inch overlapping and supporting a longitudinally-extending portion of said tip sidewall, said joint being formed of a material selected from the group consisting of molybdenum and an alloy of iron/nickel/cobalt/manganese, said joint and said tip being in physical contact only through a high temperature braze disposed intermediate said sidewall portions, a back outer corner of said tip being spaced from said joint;
and
(D) optical means, supported in said tip and responsive to the temperature of the gas stream proximate said tip, for focusing and transmitting electromagnetic radiation emitted from said tip in response to the temperature of the gas stream proximate said tip in order to effect a measurement of the temperature of the gas stream.

2 more elements

An optical probe for a gas temperature sensor for sensing the temperature of a high-temperature, high-velocity gas stream, comprising:

(A) a generally conical hollow tip for insertion into the gas stream formed of a ceramic selected from the group consisting of silicon carbide and silicon nitride to emit electromagnetic radiation at the high temperatures to be sensed, said tip defining a longitudinally-extending tip sidewall;
(B) support means for mounting said tip for interaction with the high-temperature, high-velocity gas stream;
(C) a joint physically interconnecting and spacing apart said support means and said tip, said joint being of a material and geometry to accommodate the thermal stresses caused by differences in thermal coefficients of expansion between said tip, said joint and said support means and the mechanical stresses caused by the interaction of said probe and the gas stream during high velocity movement of the gas stream past said tip, thereby to enable said probe to withstand said stresses, said joint being welded to said support means and defining a longitudinally-extending joint sidewall having a portion thereof overlapping and supporting a longitudinally-extending portion of said tip sidewall;
and
(D) optical means, removably supported in said tip and responsive to the temperature of the gas stream proximate said tip, for focusing and transmitting electromagnetic radiation emitted from said tip in response to the temperature of the gas stream proximate said tip in order to effect a measurement of the temperature of the gas stream.

2 more elements

An optical probe for a gas temperature sensor for sensing the temperature of a high-temperature, high-velocity gas stream, comprising:

(A) a generally conical hollow tip for insertion into the gas stream formed of a ceramic selected from the group consisting of silicon carbide and silicon nitride to emit electromagnetic radiation at the high temperatures to be sensed, said tip defining a longitudinally-extending tip sidewall, said tip being characterized by a high flexural strength, a high oxidation resistance, a high thermal shock resistance, and a low thermal response time constant;
(B) support means for mounting said tip for interaction with the high-temperature, high-velocity gas stream;
(C) a joint physically interconnecting and spacing apart said support means and said tip, said joint being of a material and geometry to accommodate the thermal stresses caused by differences in thermal coefficients of expansion between said tip, said joint and said support means and the mechanical stresses caused by the interaction of said probe and the gas stream during high velocity movement of the gas stream past said tip, thereby to enable said probe to withstand said stresses, said joint being welded to said support means and defining a longitudinally-extending joint sidewall having a portion thereof overlapping and supporting a longitudinally-extending portion of said tip sidewall, said joint being formed of a material selected from the group consisting of molybdenum and an alloy of iron/nickel/cobalt/maganese, said joint and said tip being in physical contact only through a high temperature braze disposed intermediate said sidewall portions, a back outer corner of said tip being spaced from said joint;
(D) optical means, removably disposed in said tip and responsive to the temperature of the gas stream proximate said tip, for focusing and transmitting electromagnetic radiation emitted from said tip in response to the temperature of the gas stream proximate said tip in order to effect a measurement of the temperature of the gas stream, said optical means comprising a leans positioned within said probe to focus infrared energy emitted from said tip;
(E) an optical fiber positioned proximate said lens to transmit focused infrared energy to an infrared detector;
and
(F) an infrared detector for providing a measurement of the temperature of the gases in the gas stream.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/071,247Filed 2 Jun 1993 · continuation in part
Priority: 17 Oct 1990
Granted: 22 Nov 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G01J 5/0014
Radiation pyrometry, e.g. infrared or optical thermometry: for sensing the radiation from gases, flames
G01J 5/04
Constructional details: casings
G01J 5/08
Constructional details: optical arrangements
G01J 5/0821
Waveguides: optical fibres