US5585914A — Apparatus and method for measuring a temperature …

Claim 1

Independent Claim 190 words

An apparatus for measuring a temperature of a high temperature liquid contained in a furnace, the apparatus comprising: an optical fiber covered with a metallic tube; a nozzle arranged on a furnace wall of the furnace and communicating with an interior of the furnace to contact said liquid contained therein, said metal-covered optical fiber being inserted through a passageway inside said nozzle; gas supply means for supplying gas into the passageway inside said nozzle to prevent said nozzle from clogging, said gas being supplied at a flow rate small enough so as to prevent said liquid contained in the furnace from solidifying around said nozzle and large enough so as to prevent said liquid contained in the furnace from entering into said nozzle; optical fiber feed means for feeding said metal-covered optical fiber through the passageway inside said nozzle into said liquid such that spectral light radiated from said liquid enters a tip of said metal-covered optical fiber and is propagated therealong; and a radiation thermometer, coupled to said metal-covered optical fiber, for determining a temperature of said liquid based on the spectral light propagated along said metal-covered optical fiber.

Claim 2

Independent Claim 190 words

An apparatus for measuring a temperature of a high temperature liquid contained in a furnace, the apparatus comprising: an optical fiber covered with a metallic tube; a nozzle arranged on a furnace wall of the furnace and communicating with an interior of the furnace to contact said liquid contained therein, said metal-covered optical fiber being inserted through a passageway inside said nozzle; gas supply means for supplying gas into the passageway inside said nozzle to prevent said nozzle from clogging, said gas being supplied at a flow rate small enough so as to prevent said liquid contained in the furnace from solidifying around said nozzle and large enough so as to prevent said liquid contained in the furnace from entering into said nozzle; optical fiber feed means for feeding said metal-covered optical fiber through the passageway inside said nozzle into said liquid such that spectral light radiated from said liquid enters a tip of said metal-covered optical fiber and is propagated therealong; and a radiation thermometer, coupled to said metal-covered optical fiber, for determining a temperature of said liquid based on the spectral light propagated along said metal-covered optical fiber.

Claim 3

Dependent Claim 21 words

The apparatus of claim 1, further comprising selection means for selecting a gas to be supplied by said gas supply means.

Claim 4

Dependent Claim 48 words

The apparatus of claim 1, wherein said nozzle has a first end which contacts said liquid, and said gas supply means includes gas velocity control means for controlling a linear velocity of the gas to range from 50 to 500 Nm/sec at said first end of said nozzle.

Claim 5

Dependent Claim 32 words

The apparatus of claim 1, wherein a ratio of an inside diameter of the passageway inside said nozzle to an outside diameter of said metal-covered optical fiber ranges from 1.5 to 3.5.

Claim 6

Dependent Claim 10 words

The apparatus of claim 1, wherein said nozzle comprises brick.

Claim 7

Dependent Claim 10 words

The apparatus of claim 1, wherein said nozzle comprises ceramics.

Claim 8

Dependent Claim 13 words

The apparatus of claim 1, wherein said nozzle comprises a single metallic tube.

Claim 9

Dependent Claim 28 words

The apparatus of claim 1, wherein said nozzle comprises a single metallic tube lined on an inner surface thereof with ceramics to define the passageway inside said nozzle.

Claim 10

Dependent Claim 53 words

The apparatus of claim 1, wherein said nozzle comprises a double-tube having an inner tube, which defines the passageway inside said nozzle, and an outer tube, said metal-covered optical fiber being inserted through the inner tube and the gas being supplied into a gap formed between the inner tube and the outer tube.

Claim 11

Dependent Claim 18 words

The apparatus of claim 1, wherein the inner tube is lined on an inner surface thereof with ceramics.

Claim 12

Dependent Claim 90 words

The apparatus of claim 1, wherein said optical fiber feed means includes: feed speed detecting means for detecting a feed speed of said metal-covered optical fiber; and feed speed control means for controlling the feed speed based on a signal outputted from the feed speed detecting means, and said gas supply means includes: pressure detecting means for detecting a pressure of the gas which is supplied into said nozzle; and gas selection means for selecting a gas to be supplied based on a signal outputted from the pressure detecting means.

Claim 13

Dependent Claim 71 words

The apparatus of claim 1, wherein said optical fiber feed means comprises a drum on which said metal-covered optical fiber is coiled, a roller for feeding said metal-covered optical fiber from the drum through the passageway inside said nozzle, a motor for driving the roller, a detector for detecting a feed speed of said metal-covered optical fiber and a speed controller for controlling the feed speed of said metal-covered optical fiber.

Claim 14

Dependent Claim 47 words

The apparatus of claim 1, wherein said optical fiber feed means includes a vibrator for vibrating said metal-covered optical fiber forwards and backwards in a direction of feeding during a stopping period when said metal-covered optical fiber is not being fed through said nozzle into said liquid.

Claim 15

Dependent Claim 69 words

The apparatus of claim 1, wherein said gas supply means includes flow rate control means for controlling a flow rate of the gas to satisfy the following equation: {Q·M·Cp·(TM-Tg)}/(Tm-T1)<4×10.sup.7 where Q: gas flow rate (Nl/min) Tm: temperature of molten metal (K) Tl: solidification temperature of molten metal (K) Tg: temperature of gas (K) Cp: specific heat of gas at temperature of molten metal (J/Kg·K) M: molecular weight of gas.

Claim 16

Dependent Claim 69 words

The apparatus of claim 1, wherein said gas supply means includes flow rate control means for controlling a flow rate of the gas to satisfy the following equation: {Q·M·Cp·(TM-Tg)}/(Tm-T1)<3×10.sup.6 where Q: gas flow rate (Nl/min) Tm: temperature of molten metal (K) Tl: solidification temperature of molten metal (K) Tg: temperature of gas (K) Cp: specific heat of gas at temperature of molten metal (J/Kg·K) M: molecular weight of gas.

Claim 17

Dependent Claim 47 words

The apparatus of claim 1, wherein said optical fiber feed means includes an optical fiber guide pipe through which said metal-covered optical fiber is guided through the passageway inside said nozzle, and a sealing device for sealing the optical fiber guide pipe and said metal-covered optical fiber.

Claim 18

Dependent Claim 120 words

The apparatus of claim 16, wherein said sealing device comprises: a plurality of sealing rubbers each having a rubber hole therein, said sealing rubbers being provided axially along said metal-covered optical fiber, the rubber holes each having a diameter smaller than a diameter of said metal-covered optical fiber; backing-up rings provided between adjacent sealing rubbers; and a lantern ring provided centrally with respect to said sealing rubbers, sealing oil being forced by pressure into the lantern ring; said plurality of sealing rubbers, said backing-up rings and said lantern ring being provided inside a body of said sealing device, and said sealing device being coupled to the optical fiber guide pipe on both ends of the body of said sealing device.

Claim 19

Independent Claim 174 words

A method for measuring a temperature of a high temperature liquid contained in a furnace comprising the steps of: providing a nozzle having a passageway therein, said nozzle being arranged on a furnace wall of the furnace and communicating with an interior of the furnace to contact said liquid contained therein; supplying gas into the passageway inside said nozzle to prevent said nozzle from clogging, said gas being supplied at a flow rate small enough so as to prevent said liquid contained in the furnace from solidifying around said nozzle and large enough so as to prevent said liquid contained in the furnace from entering into said nozzle; feeding said metal-covered optical fiber through the passageway inside said nozzle into said liquid such that spectral light radiated from said liquid enters a tip of said metal-covered optical fiber and is propagated therealong; and determining a temperature of said liquid based on the spectral light propagated along said metal-covered optical fiber, said temperature being determined by a radiation thermometer coupled to said metal-covered optical fiber.

Claim 20

Independent Claim 174 words

A method for measuring a temperature of a high temperature liquid contained in a furnace comprising the steps of: providing a nozzle having a passageway therein, said nozzle being arranged on a furnace wall of the furnace and communicating with an interior of the furnace to contact said liquid contained therein; supplying gas into the passageway inside said nozzle to prevent said nozzle from clogging, said gas being supplied at a flow rate small enough so as to prevent said liquid contained in the furnace from solidifying around said nozzle and large enough so as to prevent said liquid contained in the furnace from entering into said nozzle; feeding said metal-covered optical fiber through the passageway inside said nozzle into said liquid such that spectral light radiated from said liquid enters a tip of said metal-covered optical fiber and is propagated therealong; and determining a temperature of said liquid based on the spectral light propagated along said metal-covered optical fiber, said temperature being determined by a radiation thermometer coupled to said metal-covered optical fiber.

Claim 21

Dependent Claim 22 words

The method of claim 18, further comprising the step of selecting the gas to be supplied into the passageway inside said nozzle.

Claim 22

Dependent Claim 35 words

The method of claim 19, wherein said step of supplying gas comprises supplying a gas selected from the group consisting of an inert gas, a mixed gas of an inert gas and an oxidating gas.

Claim 23

Dependent Claim 46 words

The method of claim 18, wherein said nozzle has a first end which contacts said liquid, and said step of supplying gas comprises supplying gas such that the gas has a linear velocity ranging from 50 to 500 Nm/sec at said first end of said nozzle.

Claim 24

Dependent Claim 44 words

The method of claim 18, wherein said step of providing a nozzle comprises providing a nozzle such that a ratio of an inside diameter of the passageway inside said nozzle to an outside diameter of said metal-covered optical fiber ranges from 1.5 to 3.5.

Claim 25

Dependent Claim 72 words

The method of claim 18, wherein: said nozzle comprises a double-tube having an inner tube, which defines the passageway inside said nozzle, and an outer tube; said step of feeding said metal-covered optical fiber through the passageway inside said nozzle comprises feeding said metal-covered optical fiber through the inner tube; and said step of supplying gas comprises supplying the gas into a gap formed between the inner tube and the outer tube.

Claim 26

Dependent Claim 77 words

The method of claim 18, wherein said step of feeding said metal-covered optical fiber into said liquid includes the steps of: detecting a feed speed of said metal-covered optical fiber; and controlling the feed speed based on the detected feed speed, and said step of supplying gas into said nozzle includes the steps of: detecting a pressure of the gas being supplied into said nozzle; and selecting a gas to be supplied based on the detected pressure.

Claim 27

Dependent Claim 21 words

The method of claim 18, wherein said step of feeding said metal-covered optical fiber comprises continuously feeding said metal-covered optical fiber.

Claim 28

Dependent Claim 21 words

The method of claim 18, wherein said step of feeding said metal-covered optical fiber comprises intermittently feeding said metal-covered optical fiber.

Claim 29

Dependent Claim 53 words

The method of claim 26, wherein said step of feeding said metal-covered optical fiber includes feeding said metal-covered optical fiber and vibrating said metal-covered optical fiber forwards and backwards in a direction of feeding during a stopping period when said metal-covered optical fiber is not being fed through said nozzle into said liquid.

Claim 30

Dependent Claim 63 words

The apparatus of claim 18, wherein said step of supplying gas comprises supplying gas at a flow rate satisfying the following equation: {Q·M·Cp·(TM-Tg)}/(Tm-T1)<4×10.sup.7 where Q: gas flow rate (Nl/min) Tm: temperature of molten metal (K) Tl: solidification temperature of molten metal (K) Tg: temperature of gas (K) Cp: specific heat of gas at temperature of molten metal (J/Kg·K) M: molecular weight of gas.

Claim 31

Dependent Claim 63 words

The apparatus of claim 18, wherein said step of supplying gas comprises supplying gas at a flow rate satisfying the following equation: {Q·M·Cp·(TM-Tg)}/(Tm-T1)<3×10.sup.6 where Q: gas flow rate (Nl/min) Tm: temperature of molten metal (K) Tl: solidification temperature of molten metal (K) Tg: temperature of gas (K) Cp: specific heat of gas at temperature of molten metal (J/Kg·K) M: molecular weight of gas.

Claim 32

Dependent Claim 64 words

The method of claim 18, wherein said step of supplying gas comprises supplying gas at a flow rate satisfying the following equation: 3×10.sup.6 <{Q·M·Cp·(TM-Tg)}/(Tm-T1)<4×10.sup.7 where Q: gas flow rate (Nl/min) Tm: temperature of molten metal (K) Tl: solidification temperature of molten metal (K) Tg: temperature of gas (K) Cp: specific heat of gas at temperature of molten metal (J/Kg·K) M: molecular weight of gas.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-12-17	2000-06-17	2000-12-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-12-17	2004-06-17	2004-12-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-12-17	2008-06-17	2008-12-17	$7700.00	Window Closed / Lapsed

Apparatus and method for measuring a temperature of a high temperature liquid contained in a furnace

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