Title of Invention

THERMOCOUPLE FOR USE IN GASIFICATION PROCESS

Abstract An improved apparatus comprising a thermocouple for measuring the temperature in a gasification process is provided. The improvement comprises a sapphire envelope for enclosing at least a protion of the thermocouple. The sapphire envelope may be in the form of a sapphire sheath fitted over the thermocouple. The apparatus may also comprise a thermowell, with the sapphire envelope being provided by the thermowell.
Full Text THERMOCOUPLE FOR USE IN GASIFICATION PROCESS
FIELD OF THE INVENTION
This invention relates generally to a thermocouple used in a gasification process and,
more particularly, to the use of sapphire to extend the useful life of thermocouples used in a
gasification process.
BACKGROUND AND SUMMARY OF THE INVENTION
In high temperature gasification processes, a hot partial oxidation gas is produced from
hydrocarbonaceous fuels, for example coal. In these processes, the hydrocarbonaceous fuels are
reacted with a reactive oxygen-containing gas, such as air or oxygen, in a gasification reactor to
obtain the hot partial oxidation gas.
In a typical gasification process, the hot partial oxidation gas will substantially comprise
H2, CO2 and at least one gas from the group H2O, CO2, H2S, COS, NH3, N2, Ar, along with
particulate carbon, ash, and/or molten slag typically containing species such as SiO2,. Al2O3, and
the oxides and oxysulfides of metals such as Fe and Ca.
The hot partial oxidation gas in the gasification reactor will commonly be at a
temperature ranging from 1,700°F (927°C) to 3.000° F (1649°C), and more typically in the range
of about 2,000°F (1093°C) to 2,800° F (1538°C). and at a pressure commonly in the range of
about 1 atmosphere (98 kPa) to about 250 atmospheres (24.500 kPa), and more typically in the
range of about 15 atmospheres (1,470 kPa) to 150 atmospheres (14,700 kPa).
Thermocouples are commonly used for measuring temperature in these high temperature
processes. The thermocouples can be used to measure the temperature in the gasification
reactor. They may also be used to measure the temperature in downstream process steps in
which the effluent is cooled and paniculate and gaseous contaminants are removed.

Thermocouples are pairs of wires of dissimilar metals which are connected at both ends.
The content of the wires must be sufficiently dissimilar to allow for a difference in electrical
potential between them. Except for the ends, the two wires are electrically insulated from each
other. The electrical insulation is commonly provided by a tube of insulating material having
two non-intersecting holes passing lengthwise through the tube. Typical insulating materials
include high temperature, high purity ceramics, such as alumina.
When the two junctions of the wires are at different temperatures, a difference in
electrical potential exists between them. The difference in electrical potential and therefore the
difference in temperature can be measured by a voltage measuring instrument placed in the
thermocouple circuit or alternatively by a voltage measuring instrument that is sent signals by a
transmitter placed in the thermocouple circuit.
The choice of dissimilar metals used for the thermocouple will vary depending on,
among other things, the expected temperature range to be measured. For instance, one type of
thermocouple commonly employed under the conditions present in a gasification reactor has one
wire that contains platinum and about 30% rhodium and a second wire that contains platinum
and about 6% rhodium. Other pairs of metals are used for different temperature ranges.
One problem apparent with the use of thermocouples in the environment present in a
gasification process, particularly the environment present in the gasification reactor, is the
relatively short lifespan of the thermocouples. The relatively short lifespan is due in part to the
extremely high temperatures and corrosive atmosphere that prevails during the operation of the
gasification reactor. An unprotected thermocouple left in this environment is quickly attacked
and rendered useless. Such attack can be most severe when the thermocouple comes into contact
with molten slag present in the reactor.

To alleviate this problem, thermocouples are commonly inserted into a refractory
thermowell disposed along the outer wall of a gasification reactor or other exterior process
surface. The refractory thermowells would include barriers of chrome-magnesia, high chrome,
or similar slag resistant materials, and may incorporate other refractory and non-refractory
materials such as A12O3, MgO, and stainless steel.
When used in a gasification reactor, the thermowell may be introduced by passing it
through an opening in the outer wall of the reactor pressure vessel. The thermowell may then
pass through a corresponding opening in a refractory material, or series of refractory materials,
commonly used to line the inner surface of the reactor pressure vessel. The thermowell may
extend into the open space of the reactor or it may be set back at a slight distance from the
interior of the reactor.
Unfortunately, positioning the thermocouple inside a thermowell has not provided a
complete solution. Over time, molten slag will breach the thermowell. The breach is commonly
due to the effects of erosion and corrosion as well as thermal and/or mechanical stress.
However, the breach may also be due, totally or in part, to an inherent fault in the thermowell.
The breach, typically small initially, allows molten slag to enter the thermowell where it can
come in contact with the thermocouple, rendering it useless.
It would therefore be beneficial to have a means to increase the lifespan of thermocouples
used in a gasification process.
In accordance with one aspect of the present invention, an improved apparatus
comprising a thermocouple for measuring the temperature in a gasification process. The
improvement comprises a sapphire envelope for enclosing at least a portion of the thermocouple.
The sapphire envelope may be in the form of a sapphire sheath fitted over the thermocouple.

The apparatus may also comprise a thermowell, with the sapphire envelope being provided by
the thermowell.
In accordance with another aspect of the invention, an improved apparatus for measuring
the temperature in a gasification process comprising a thermowell and one or more
thermocouples is provided. The improvement comprises a sapphire envelope for enclosing at
least a portion of at least one thermocouple. The sapphire envelope may be in the form of a
sapphire sheath fitted over the thermocouple. The thermowell may contain at least one barrier
layer comprised of sapphire, with the sapphire envelope being equivalent to the barrier layer
comprised of sapphire.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRA WINGS
Figure 1 depicts a thermocouple produced in accordance with one aspect of the
invention.
Figure 2 depicts a segmentary view in cross-section of a portion of gasification reactor
wall in which a thermocouple and thermowell are installed in accordance with one aspect of the
invention.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Gaseous mixtures substantially comprising H2,. CO, and at least one gas from the group
H2O, CO2, H2S, COS, NH3, N2, Ar, along with particulate carbon, ash and/or molten slag
typically containing species such as SiO2. Al2O3, and the oxides and oxysulfides of metals such
as Fc and Ca are commonly produced by well known partial oxidation processes in the reaction
zone of a free-flow, down-flowing vertical refractory lined steel pressure vessel. An example of
such a process and pressure vessel are shown and described in coassigned U.S. Patent No.
2,818,326 hereby incorporated by reference. In such a process, the partial oxidation gas will

typically be subjected to cooling and additional purification steps in which particulate
contaminants, gaseous contaminants, and water vapor are removed.
The partial oxidation gas produced from such a process will, depending on chemical
composition and intended end use, commonly be referred to as synthesis gas, fuel gas. or
reducing gas. The generic partial oxidation gas will be referred to herein as encompassing all of
these potentialities.
The feed used to produce the partial oxidation gas comprises hydrocarbonaceous fuels.
The term "hydrocarbonaceous"" as used herein to describe various suitable feedstocks is intended
to include gaseous, liquid, and solid hydrocarbons, carbonaceous materials, and mixtures
thereof. In fact, substantially any combustible carbon-containing organic material, or slurries
thereof, may be included within the definition of the term "hydrocarbonaceous". For example,
there are (1) pumpable slurries of solid carbonaceous fuels, such as particulate carbon dispersed
in a vaporizable liquid carrier, such as water, liquid hydrocarbon fuel, and mixtures thereof; and
(2) gas-liquid-solid dispersions, such as atomized liquid hydrocarbon fuel and particulate carbon
dispersed in a temperature moderating gas.
The term "liquid hydrocarbon," as used herein to describe suitable liquid feedstocks, is
intended to include various materials, such as liquefied petroleum gas. petroleum distillates and
residua, gasoline, naphtha, kerosene, crude petroleum, asphalt, gas oil. residual oil. tar-sand oil
and shale oil, coal derived oil. aromatic hydrocarbons (such as benzene, toluene, xylene
fractions), coal tar. cycle gas oil from fluid-catalytic-cracking operations, furfural extract of
coker gas oil. and mixtures thereof.

"Gaseous hydrocarbons,"1 as used herein to describe suitable gaseous feedstocks, include
methane, ethane, propane, butane, pentane, natural gas. coke-oven gas, refinery gas, acetylene
tail gas, ethylene off-gas, and mixtures thereof.
"Solid hydrocarbon fuels," as used herein to describe suitable solid feedstocks, include,
coal in the form of anthracite, bituminous, subbituminous; lignite; coke; residue derived from
coal liquefaction; peat; oil shale; tar sands; petroleum coke; pitch; paniculate carbon (soot or
ash); solid carbon-containing waste materials, such as sewage; and mixtures thereof.
Solid, gaseous, and liquid feeds may be mixed and used simultaneously; and these may
include paraffinic, olefinic, acetylenic, naphthenic, and aromatic compounds in any proportion.
Also included within the definition of the term "hydrocarbonaceous" are oxygenated
hydrocarbonaceous organic materials including carbohydrates, cellulosic materials, aldehydes,
organic acids, alcohols, ketones, oxygenated fuel oil. waste liquids and by-products from
chemical processes containing oxygenated hydrocarbonaceous organic materials, and mixtures
thereof.
In the reaction zone of a gasification reactor, the hydrocarbonaceous fuel is contacted
with a free-oxygen containing gas. optionally in the presence of a temperature moderator. The
reaction time will typically be in the range of about 1 to 10 seconds, and preferably about 2 to 6
seconds. In the reaction zone, the contents will commonly reach temperatures in the range of
about 1,700°F (927°C) to 3.000° F (1649°C). and more typically in the range of about 2.000° F
(1093°C) to 2,800° F (1538°C). Pressure will typically be in the range of about latmophere (98
kPa) to about 250 atmospheres (24.500 kPa). and more typically in the range of about 15
atmospheres (1.470 kPa) to about 150 atmospheres (14,700 kPa). As the partial oxidation gas

proceeds downstream, the temperature of the flow will be reduced as the gas is subjected to
various cooling, washing, and other steps.
In accordance with the present invention, temperature may be measured at various
locations within the gasification process by thermocouples having employed therewith a
sapphire envelope. The use of a sapphire envelope in accordance with the various embodiments
of the invention, amongst other advantages, increases the useful life of the thermocouple over
conventional thermocouples. In its various embodiments, the sapphire envelope will enclose at
least a portion of a thermocouple with which it is employed. The use of the sapphire envelope is
particularly advantageous when it is used in conjunction with thermocouples positioned so as to
measure the temperature in the gasification reactor, as the detrimental effects of high
temperatures, molten slag, and corrosives are most prevalent in the reactor.
In one embodiment of the present invention, the sapphire envelope is manifested in the
form of a sapphire sheath 24 that fits over at least a portion of a thermocouple. In this
embodiment, illustrated in Figure 1. a thermocouple 10 is provided. The thermocouple 10 is
comprised of a pair of wires 12 and 14. The wires have dissimilar metal content such that a
difference in electrical potential can develop between them when the thermocouple is exposed to
a heat source. The wires, for example, may both contain platinum and rhodium as their primary
substituents with the amounts of platinum and rhodium being different in the two wires.
Preferably one of the wires has about 30% rhodium while the other wire has about 6% rhodium.
For both wires, the remainder is primarily platinum.
The wires are joined to each other at a hot junction 16 and cold junction 18. The terms
"hot" and "cold" arc used because when employed to measure the temperature of a gasification
reactor the hot junction 16 is positioned closer to the heat source. The difference between the

electrical potential of the two wires, being representative of the temperature at the hot end, is
measured. It is not critical how the difference in potential is measured. In fact, various means
are known to those of ordinary skill in the art for measuring the difference in electrical potential.
Any of these methods can be used in the present invention. For example, a voltage meter can be
placed in the thermocouple circuit. Alternatively, and preferably, the cold junction 18 is
provided at a temperature transmitter. The signal generated by the temperature transmitter can
then be relayed to a control room or other location by signal transfer means 20.
Except for the hot and cold junctions, the two wires 12 and 14 are otherwise electrically
insulated from each other. While it is not critical how insulated, in this embodiment, the
electrical insulation 22 is provided by a high temperature, high purity ceramic tube. Such a
ceramic tube can be made of, for example, alumina.
If the thermocouple disclosed to this point was utilized alone or in combination with a
typical thermowell in order to measure the temperature of a gasification reactor, the
thermocouple would, as disclosed, succumb to the slag and other detrimental materials present in
the reactor relatively quickly. It is for this reason that in the present embodiment a sapphire
sheath 24 is provided to fit over at least a portion of the thermocouple. The sapphire sheath 24 is
substantially resistant to attack from the slag and other products of the gasification process. The
completed thermocouple, comprising the improved sapphire sheath 24, can thus be viewed as
having a distal end 26 adjacent to the hot junction 16.
It is necessary that the sapphire sheath 24 enclose at least the hot junction 16. Preferably,
and as subsequently detailed, the sapphire sheath 24 will be of sufficient length such that before
the molten slag reaches the top of the sapphire sheath 24 the molten slag will cool and reach a
state of nominal or zero flow or a breach will form at some other point on the sapphire sheath.

In the present embodiment, the sapphire sheath 24 is substantially tubular having an
enclosed end. being equivalent to the distal end 26 of the thermocouple, and an open end 28, the
opening at the open end 28 being capable of receiving and fitting over the existing thermocouple
comprised of the two wires 12 and 14 and the electrical insulation 22 surrounding and insulating
the wires. In a variation of the embodiment, an enlarged plug 30 of sapphire is provided at the
enclosed end of the sapphire sheath 24. The enlarged plug 30 increases the time it takes for the
slag to penetrate the sapphire sheath 24. The presence of enlarged plug 30, in its simplest form,
may be due to the fact that the sheath may be inherently thicker at the enclosed end than on its
sides.
In the present embodiment, the sapphire sheath 24 fits over and covers only a portion of
the existing thermocouple. The open end 28 advantageously should fit tightly over electrical
insulation 22. Platinum foil wrapped around the electrical insulation 22 or wrapped around the
inner surface of the sheath 24 can be advantageously used to provide a good fit for the sapphire
sheath 24. In other embodiments, the sapphire sheath 24 may extend over and cover a larger
portion, if not substantially all of the existing thermocouple. In still other embodiments,
sapphire may be used to both electrically insulate the two wires as well as sheath the wires. In
such an embodiment, the sapphire sheath 24 and the electrical insulation 22 would both be
comprised of sapphire.
In other embodiments of the invention, any one of the disclosed thermocouples having a
sapphire sheath 24 is advantageously combined with a thermowell. The combined apparatus is
advantageously used to measure the temperature in a gasification process, particularly in a
gasification reactor. Any thermowell commonly used or subsequently developed by one of
ordinary skill in the art can be employed. Such thermowells would include barriers of chrome-

magnesia, high chrome, or similar slag resistant materials, and may incorporate other refractory
and non-refractory materials such as Al2O3, MgO, and stainless steel.
In a preferred thermowell, illustrated in combination with a thermocouple of the present
invention in Figure 2, the thermowell is comprised of an inner protection tube 62 and an outer
protection tube 64. The inner protection tube 62 can be formed from a high density low porosity
refractory, such as alumina or magnesia. A castable refractory material, typically a high density
low porosity refractory, is then poured around the inner protection tube 62 and allowed to set so
as to form the outer protection tube 64 around all but the opening of the inner protection tube 62.
Preferably, this castable high density low porosity refractory material is comprised of chromium
oxide or chromia-magnesia.
In this embodiment the thermocouple 10 is inserted into the thermowell, distal end 26
first. The thermocouple 10 is passed through a flanged reducer 76 and into the thermowell in
contact with and mated to the flanged reducer 76. The distal end 26 of the thermocouple 10 is
positioned adjacent to the tip 66 of the thermowell. A gap of about 0.125inches (3.18x10-1 m) to
about 0.25 inches (6.35x10-3 m) is preferably maintained between the inside surface of tip 66 of
the thermowell and the distal end 26 of the thermocouple.
The upstream ends of the wires 12 and 14 of the thermocouple 10 extend past the back
end of the electrical insulation 22. and/or the sapphire sheath 24 if the sheath is coterminous with
the electrical insulation 22. The wires pass through a pressure sealing fitting 70. The pressure
sealing fitting 70 contacts a bushing 72 which fits into a removable flange 74. The flange 74
mates with flange reducer 76 that is mated to the outer steel wall 40 of the pressure vessel
gasification reactor.

The thermocouple 10 and thermowell assembly is held in place by bolting or clamping
together flange 74 to flange reducer 76 and similarly bolting or clamping together flange reducer
76 to the outer steel wall 40 of the pressure vessel gasification reactor. The use of two separate
connections provides for increased efficiency in that a thermocouple 10 can be replaced without
removing the thermowell. Instead of mating flanges, threaded caps and nozzles or other
connection means can be used.
The thermowell, with or without attached thermocouple 10, is passed in succession
straight through a hole in the steel wall 40 of the pressure vessel gasification reactor and then
through an aligned hole in the refractory 42 lining the wall on the inside of the pressure vessel.
The tip 66 of the thermowell is preferably positioned so as to be retracted from about 0.25 to
about 0.75 inches (0.019m), preferably 0.5 inches (0.0127 m). from the face of the refractory 42
lining the inside steel wall of the pressure vessel reactor. In this manner, the rate of erosion is
reduced as opposed to when the tip 66 of the thermowell is positioned even with the face of the
refractor}" 42 or beyond the face of the refractory 42.
The thermocouple 10 and thermowell assembly positioned in a gasification reactor
exhibits increased resistance to slag. In the gasification reactor, molten slag 50 deposits out on
the inside walls of the refractory 42 lining the inside steel wall of the pressure vessel reactor.
The molten slag 50 will migrate toward the thermowell. As disclosed, over time the effects of
erosion and corrosion as well as thermal and/or mechanical stress may cause a small breach in
the tip 66 of the thermowell. When this occurs, the molten slag 50 will, moving toward cool
spots, migrate through the breach and enter the inner protection tube 62, thereby coming in
contact with the sapphire sheathed thermocouple. Advantageously, with the sapphire sheath 24.
the wires 12 and 14 and hot junction 16 are shielded from the molten slag 50 and its destructive

effects. The molten slag 50 will continue to migrate up the interior of the inner protection tube
62 until it cools to the point at which it achieves a state of zero or nominal flow. Because of this,
the sapphire sheath 24 should be of sufficient length such that before the slag can reach the open
end 28 of the sapphire sheath 24, one of two things will occur: the molten slag 50 will achieve
thermal equilibrium, cool, and achieve a state of nominal or zero flow; or a breach will form at
some other point on the sapphire sheath. This second possibility might occur first when the
effects of erosion and corrosion as well as thermal and/or mechanical stress cause the entire tip
66 of the thermowell to be removed. When this occurs, the sapphire sheath 24 becomes onset by
the full effects of erosion and corrosion in the gasification reactor. A breach ultimately forms in
the sapphire sheath 24. With the wires 12 and 14 and the hot junction 16 unprotected, the
thermocouple 10 fails. The selection of an appropriate length for the sapphire sheath 24 is
within the skill of one of ordinary skill in the art having knowledge of the characteristics of their
specific process, including temperature and gas composition, and having the benefit of this
disclosure.
In other embodiments, one or more, and preferably three, thermocouples are inserted into
a thermowell having at least a corresponding number of inner protection tubes 62. In such a
preferred embodiment, the distal ends of the one or more thermocouples are advantageously
positioned at different points along the length of the thermowell. This arrangement provides for
increased times between thermocouple and thermowell replacement. For example, in an
embodiment in which a total of three thermocouples are used, slag ultimately penetrating the
thermowell will reach the thermocouple positioned closest to the tip 66 first. This thermocouple
will subsequently fail. It then takes an additional amount of time for the slag to reach and cause
the failures of the second and third thermocouples. Thus, the process can be run longer without

need for shut down. While the accuracy provided by the second and third thermocouples is not
as good as the first thermocouple, the difference does not pose a problem for process control as
the readings for the second and third thermocouples may be corrected based on data gathered
prior to the failure of the first thermocouple.
In other embodiments, the sapphire envelope can be provided by utilizing a thermowell
fabricated wholly or in part from sapphire. Such a thermowell could have sapphire, preferably in
the form of sapphire fiber, intermixed throughout the thermowell. Such a thermowell could also
have at least one substantially continuous barrier layer comprised of sapphire. These
thermowells could be used with a thermocouple that did not have a separate sapphire sheath.
Alternatively, these thermowells could be employed with sapphire sheathed thermocouples. In
one illustrative embodiment of a thermowell having at least one substantially continuous barrier
layer comprised of sapphire, an inner protection tube 62 of the thermowell could be formed of
sapphire.
In other embodiments, a thermocouple having a sapphire sheath could be used without a
thermowell to measure the temperature in a gasification process. However, this alternative is not
preferred where the thermocouple would be exposed to molten slag. While a thermocouple
sheathed with sapphire will withstand the full effects of erosion and corrosion in the gasification
reactor for a longer time than a thermocouple not having a sapphire shield, the use of a
thermocouple having a sapphire shield in conjunction with a thermowell dramatically increases
the lifespan of the thermocouple so used.

We Claim
1. An apparatus comprising one or more thermocouples (10) for measuring
the temperature in a gasification process characterized in that at least a
portion of at least one thermocouples (10) is enclosed in a sapphire
envelope (24).
2. An apparatus as claimed in claim 1, wherein said one or more
thermocouples (10) each independently comprise a pair of wires (12, 14)
of dissimilar metal content joined together at one end by a hot junction
(16) and at the other end by a cold junction (18) but otherwise electrically
insulated from each other by an insulating tube (22).
3. An apparatus as claimed in claim 2 wherein the sapphire envelope (24) is
in the form of a sapphire sheeth having a closed distal end (26) and an
open end (28), said open (28) having been fitted over the hot junction
(16) and at least a portion of the insulated tube (22).
4. An apparatus as claimed in any of the preceding claims comprising a
thermowell surrounding said one or more thermocouples (10).
5. An apparatus as claimed in claim 4 wherein the thermowell has at least
one barrier layer (62) comprised of sapphire.
6. An apparatus as claimed in claim 4 wherein the thermowell comprises an
inner protection tube (62) and an outer protection tube (64).

7. An apparatus as claimed in claim 6 wherein the inner protection (62) tube
is comprised of alumina or sapphire.
8. An apparatus as claimed in claim 6 wherein said inner protection tube (62)
comprises said sapphire envelope (24).
9. An apparatus as claimed in any of the preceding claims, wherein the one
or more thermocouples are under the ambient pressure of the gasification
process.
10. An apparatus as claimed in any of the preceding claims, wherein the
temperature to be measured range from about 927°C (1,700 °F) to about
1649 °C (3000 °F).
11. An apparatus as claimed in any one of the preceding claims, wherein the
pair of wires (12, 14) are comprised of platinum, rhodium or mixtures
thereof.
12. An apparatus as claimed in any one of the preceding claims, wherein the
insulating tube (22) is comprised of alumina or sapphire.
13. An apparatus as claimed in any of claims 4 to 12, comprising one or more
inner protection tubes (62), wherein the number of inner protection tubes
(62) is at least equivalent to the number of thermocouples (10), and
wherein the distal ends of the one or more protection tubes (62) are
positioned at different points along the length of the thermowell.

14. An apparatus as claimed in any of claims 4 to 13, comprising a reactor
having a vertical free-flowing refractory lined cylindrical steel pressure
vessel, the thermowell being installed in the reactor by first passing it
through a hole in the steel wail (40) of the pressure vessel by then
passing it through an aligned hole in the refractory lining (42) the wall on
the inside of the pressure vessel, the one or more thermocouples (10)
being installed in the reactor by passing the thermocouples (10) in
succession straight through a flanged reducer (26) and into the
thermowell connected to the flanged reducer (76).
15. A thermocouple (16) comprising a pair of wires (12, 14) of dissimilar
metal content joined together at one end by a hot junction (16) and at the
other end by a cold junction (18) but otherwise electrically insulated from
each other by an insulating tube (22), the thermocouple (10) comprising a
sapphire sheath (24) having a closed distal end (26) and an open end
(28), said open end (28) having been fitted over the hot junction (16) and
at least a portion of the insulating tube (22).
An improved apparatus comprising a thermocouple for measuring the temperature in a
gasification process is provided. The improvement comprises a sapphire envelope for enclosing
at least a portion of the thermocouple. The sapphire envelope may be in the form of a sapphire
sheath fitted over the thermocouple. The apparatus may also comprise a thermowell, with the
sapphire envelope being provided by the thermowell.

Documents:

IN-PCT-2000-641-KOL-FORM 27.pdf

in-pct-2000-641-kol-granted-abstract.pdf

in-pct-2000-641-kol-granted-claims.pdf

in-pct-2000-641-kol-granted-correspondence.pdf

in-pct-2000-641-kol-granted-description (complete).pdf

in-pct-2000-641-kol-granted-drawings.pdf

in-pct-2000-641-kol-granted-examination report.pdf

in-pct-2000-641-kol-granted-form 1.pdf

in-pct-2000-641-kol-granted-form 18.pdf

in-pct-2000-641-kol-granted-form 2.pdf

in-pct-2000-641-kol-granted-form 26.pdf

in-pct-2000-641-kol-granted-form 3.pdf

in-pct-2000-641-kol-granted-form 5.pdf

in-pct-2000-641-kol-granted-letter patent.pdf

in-pct-2000-641-kol-granted-reply to examination report.pdf

in-pct-2000-641-kol-granted-specification.pdf

in-pct-2000-641-kol-granted-translated copy of priority document.pdf


Patent Number 216081
Indian Patent Application Number IN/PCT/2000/641/KOL
PG Journal Number 10/2008
Publication Date 07-Mar-2008
Grant Date 06-Mar-2008
Date of Filing 18-Dec-2000
Name of Patentee TEXACO DEVELOPMENT CORPORATION
Applicant Address 2000 WESTCHESTER AVENUE, WHITE PLAINS, NEW YORK 10650
Inventors:
# Inventor's Name Inventor's Address
1 GREEN, STEVEN R. 607 PRAIRIC ROAD, ELDORADO KANSAS 67042
2 POWELL, DAVID L. JR. 330 E. CLARK AVENUE, AUGUSTA, KANSAS 67010
PCT International Classification Number G 01 K 1/10
PCT International Application Number PCT/US99/14281
PCT International Filing date 1999-06-25
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 09/106,133 1998-06-26 U.S.A.