1
WO 2006/135189 PCT/KR2006/002261
Description
TEMPERATURE MEASURING DEVICE
Technical Field
The present invention relates to a temperature measuring device, and more par-
ticularly to a temperature measuring device which can be used to measure temperature
in a tubular reactor, preferably to easily measure temperature of a catalyst layer in a
shell-and-tube heat exchanger-type reactor including at least one reaction tube which is
filled with the fixed catalyst layer(s).
Background Art
The shell-and-tube heat exchanger-type reactor may be used for catalytic vapor
phase oxidation, for example, for a process of manufacturing unsaturated acid from
olefin using a catalyst in vapor.
Generally, the shell-and-tube heat exchanger-type reactor includes reaction tubes
filled with at least one kind of granule catalyst, which receives reaction gas provided
through a pipe. In the heat exchanger-type reactor, the reaction gas contacts with and
reacts upon the catalyst in the reaction tubes so as to generate a desired product.
Reaction heat generated in the reaction is transferred to and removed by heat
transferring media which circulate in shells provided on a peripheral surface of the
reaction tubes and are maintained at a predetermined temperature. The reaction
mixture containing the desired product is carried through a pipe to a recovery and
refining device.
Generally, catalytic vapor phase oxidation is a highly exothermic reaction.
Therefore, it is important to control reaction temperature in a certain range as well as to
reduce the size of the temperature peak at a hot spot occurring in a reaction zone.
Specifically, it is very important to rapidly detect a location of the heat point in the
catalyst layer and to accurately measure the size of the temperature peak at the hot
spot, in consideration of process conditions, feed composition, and structure of catalyst
layers.
In order to measure temperature of the hot spot, the conventional shell-and-tube
heat exchanger-type reactor includes a plurality of reaction tubes each of which has a
thermo-well tube mounted therein and at least one thermocouple. Some of the ther-
mocouples are fixed type thermocouples which are located at fixed points in the
reaction tube, while the rest are movable type thermocouples which can be inserted
into and drawn into and out the thermo-well tube as well as moved within some range
of the thermo-well tube.
In such a temperature measuring device, the role of the movable thermocouple is

2
WO 2006/135189 PCT/KR2006/002261
very important. As described above, the location of the hot spot is determined
according to the process conditions, the feed composition, and the structure of the
catalyst layers, while the size of the temperature peak at a hot spot is also determined
according to the heat controlling capacity of the heat transferring media. Therefore, it
is necessary to insert or draw the movable thermocouple into and out the thermo-well
tube so as to monitor the accurate location and size of the hot spot.
Further, the movable thermocouple helps an operator to obtain the temperature
profile of the entire catalyst bed for the whole length of the reaction tube. There are
much information obtained from the temperature profile of the catalyst bed, through
which the operator can easily and visually analyze whether the hot spot is occurred,
whether the catalyst particles are evenly distributed, whether it is necessary to control
the reaction temperature, and whether the reactor normally operates.
However, since the temperature of the catalyst layer in the reactor having the fixed
catalyst layer generally increases to 200°C ~ 500°C due to the highly exothermic
reaction, the thermo-well tube protecting the thermocouple is thermally expanded and
extremely deformed due to bending or twisting, thereby making it difficult to move the
thermocouple.
In order to obtain the temperature profile of the catalyst layer, the thermocouple
having a low mechanical strength should be inserted into the reaction tube along its
whole length, i.e. from several meters to several tens of meters in the thermo-well tube.
However, the thermocouple is subjected to a great friction resistance while moving in
the thermo-well tube deformed by the thermal effect, so that its sensor may fail to
reach a desired point in the thermo-well tube. Furthermore, the thermocouple may be
. broken due to an unsuitable insertion thereof.
When the thermocouple is broken while it is being inserted in the thermo-well tube,
there is no way to withdraw the inserted broken thermocouple from the thermo-well
tube, resulting in a seriously negative effect on the monitoring of the temperature.
Disclosure of Invention
Technical Problem
Accordingly, the present invention has been made to solve the above-mentioned
problems occurring in the prior art, and an object of the present invention is to provide
a temperature measuring device which has a temperature measuring means, such as a
thermocouple, capable of easily moving even in a deformed thermo-well tube.
Technical Solution
In order to accomplish the object, the present invention provides a temperature
measuring device comprising: a thermo-well tube; and a cable or wire type temperature
measuring means which is installed in a thermo-well tube, wherein temperature

3
WO 2006/135189 PCT/KR2006/002261
measuring means has temperature detecting sensors disposed at an intermediate portion
thereof, and the temperature detecting sensors can be moved axially in the thermo-well
tube by applying tension to both ends of the cable or wire type temperature measuring
means. The present invention also provides a reaction tube in which the temperature
measuring device is disposed axially, and a reactor including the temperature
measuring device as described above and/or the reaction tube as described above.
The temperature measuring device according to the present invention can be
installed in a reaction tube or a shell space of the reactor.
Brief Description of the Drawings
FIG. 1 is a schematic view of a shell-and-tube heat exchanger-type reactor having a
temperature measuring device according to the present invention.
FIG. 2 is a schematic view showing a thermocouple and a thermo-well tube.
FIG. 3 is a schematic view showing a variation of the temperature detecting sensor
in the temperature measuring device according to the present invention.
FIG. 4 is a schematic view showing another variation of the temperature detecting
sensor in the temperature measuring device according to me present invention.
Mode for the Invention
Hereinafter, a preferred embodiment of the present invention will be described with
reference to the accompanying drawings.
As shown in FIG. 1, the present invention is characterized in that a temperature
measuring means installed in a thermo-well tube is made in a cable or a wire type and
has temperature detecting sensors disposed at an intermediate portion thereof, thereby
to enable the temperature detecting sensors to move axially in the thermo-well tube
when the temperature measuring means is subjected at both ends thereof to tension.
Preferably, pulleys are installed at the outside of openings formed at both ends of
the thermo-well tube respectively, by which the cable or wire type temperature
measuring means is suspended. The direction for applying the tension can be changed
by using the pulleys while the tension is applied to the temperature measuring means.
Further, a position of the temperature detecting sensors can be easily moved by using a
little force. Thus, if the temperature measuring means is merely pulled using the
tension, the operator can easily measure the temperature in the entire region of the
tubular reactor and can facilitate to identify the thermal stability of the entire catalyst
layer in the reaction tube.
Further, the cable or wire type temperature measuring means preferably has the
flexibility. When the temperature measuring means is made of a flexible material like
wire, the flexibility of the temperature measuring means can compensate for a
weakened movement of the temperature measuring means even though the thermo-

4
WO 2006/135189 PCT/KR2006/002261
well tube is deformed. Specifically, it is possible to prevent the temperature measuring
means from being damaged due to the mechanical friction occurring when the
temperature measuring means is pushed and inserted into the thermo-well tube.
In the temperature measuring means according to the present invention, it is
preferable that the temperature detecting sensor is embedded in the tubular shaped
junction portion and the cable or wire type temperature measuring means is physically
connected to the junction portion.
Two cable or wire type temperature measuring means may be linearly connected to
each other. In the case of using two temperature measuring means, even though one of
the temperature detecting sensors gets out of order due to the deterioration thereof or
the mechanical friction during the movement thereof, it is possible to continuously
measure the temperature using the remaining one.
According to the present invention, the thermo-well tube is made of stainless steel.
However, the present invention does not limit the material for the thermo-well tube to
that described above. If necessary, the stainless steel containing relatively more carbon
may be used in order to increase the hardness of the thermo-well tube. Further, the
stainless steel containing relatively more chrome may be used in order to increase the
high-temperature hardness and the corrosion resistance of the thermo-well tube. In
addition, the stainless steel containing relatively more nickel may be used in order to
increase the corrosion resistance and the toughness of the thermo-well tube. In order to
increase the acid resistance of the thermo-well tube so as to prevent the corrosion of
the thermo-well tube due to high acid material, an alloy containing molybdenum, such
as hastelloy, may be used as the material for the thermo-well tube.
On the other hand, in a case where there exists a difficulty in transferring heat in the
thermo-well tube, oil used for a high temperature may be filled in the thermo-well
tube, thereby reducing the resistance for the heat transfer.
The cable or wire type temperature measuring means according to the present
invention includes thermocouples and resistance temperature detectors. However, the
present invention does not limit the temperature measuring means to those described
above. In consideration of temperature range to be measured and reaction time to be
required, the thermocouple or the resistance temperature detector suitable for the
measured object can be selected.
Hereinafter, the present invention will be described in detail with relation to the
thermocouple.
The thermocouple is made in such a manner that two kinds of conductive metals are
adhered to each other so as to form a closed circuit. The principle of the thermocouple
is that when both contact points of the thermocouple have different temperatures,
electric current flows between the contact points of the thermocouple. Thus, the

5
WO 2006/135189 PCT/KR2006/002261
operator measures the electric current and then identifies the temperature difference
between the contact points of the thermocouple. Therefore, if the contact points
(hereinafter, referred to as a thermocouple sensor) of the thermocouple are located at
suitable position in the thermo-well tube, it is possible to accurately measure
temperature. Accordingly, the thermo-well tube is necessary for protecting the
thermocouple in order to locate the thermocouple sensor at the accurate position and
the suitable circumstance.
FIG. 2 is a schematic view showing the thermocouple and the thermo-well tube.
Referring to FIG. 2, there are two filaments 210a and 210b made of different
materials, of which one ends are jointed to each other so as to form a sensor 212 of the
thermocouple.
Such a thermocouple sensor 212 detects temperature at a certain position and
converts it into electric signal. On the other hand, the remaining portion of the
filaments 210a and 210b, excepting the thermocouple sensor 212, is insulated by
means of an insulator 214. Further, the insulator 214 can supply supporting force to the
contact point 212 of the filaments 210a and 210b so that the contact point 212 is
located over a flat zone.
Meanwhile, the thermo-well tube 218 for the thermocouple is used for protecting
the thermocouple from a high temperature, an acid, a base, and a mechanical friction,
etc. The thermocouple 216 including the filaments 210a and 210b and the insulator 214
is inserted into a linear type thermo-well tube 218 having a predetermined length.
Preferably, the thermo-well tube 218 for the thermocouple is installed at a central
portion of a cross-section perpendicular to the axis of reaction tube, of which the
temperature is measured.
The inner space of the thermo-well tube is insulated from the reacting field. Further,
the position at which the temperature will be measured, i.e. the position of the
thermocouple sensor, can be changed by adjusting the tension applied to both ends of
the thermocouple.
FIG. 1 schematically shows a shell-and-tube heat exchanger-type reactor 20 in
which the temperature measuring device according to the present invention is installed.
In the cable or wire type temperature measuring means according to the present
invention, a pair of tiiermocouples, which are linearly connected to each other, is
preferably used. Thus, the present invention will be described with respect to the
temperature measuring means having the pair of thermocouples.
The shell-and-tube heat exchanger-type reactor generally includes several
thousands to several tens of thousands of reaction tubes. However, FIG. 1 shows only
one representative reaction tube 10 in order to illustrate the present invention.
Reference numeral 1 depicts one thermocouple, reference numeral 2 indicates a sensor

6
WO 2006/135189 PCT/KR2006/002261
of the thermocouple for detecting temperature, and reference number 3 shows another
thermocouple. Further, reference numeral 4 depicts a sensor of the thermocouple 3,
reference numeral 5 indicates a thermo-well tube, reference numeral 6 depicts a pulley
for supporting the thermocouple 1, and reference 7 shows a winder for winding and
drawing the thermocouple 1 thereon, which manually or automatically operates.
Reference numeral 8 depicts a pulley for supporting the thermocouple 3, and reference
numeral 9 depicts a winder for winding and drawing the thermocouple 3. In FIG. 1,
reference numeral 30 indicates a direction of drawing the thermocouple 1, and a
reference numeral 40 shows a direction of drawing the thermocouple 3. Reference
numeral 11 depicts a device for displaying the temperature measured by the sensors,
which converts electric signal into the temperature value.
If the thermocouples 1 and 3 have sufficient flexibility and are used like a wire
which can be bent and wound, the present invention does not limit the material for the
thermocouples. The thermocouples preferably are smoothly unrolled due to their
ductility and malleability when they are to be drawn by using the tension. Therefore,
the thermocouples are very advantageous of passing through the deformed thermo-well
tube.
Meanwhile, the method of connecting the pair of thermocouples is shown in detail
in FIGS. 3 and 4.
Preferably, the sensors of the pair of thermocouples are embedded and connected in
one junction portion (see FIG. 3), or the sensors are embedded in the junction portions
respectively before the junction portions are connected to each other by a connection
member (see FIG. 4).
As shown in FIG. 3, two thermocouples are connected by the junction portion 50.
At this time, the tube type junction portion 50 receives the thermocouples 1 and 3 and
is subjected to pressure at a portion overlapping with a portion of the thermocouple but
me sensor, so as to be integrated with the thermocouple. As described above, the
junction portion is necessary for connecting two independent wire type temperature
measuring means, for example thermocouples.
The junction portion can be made of material similar to that of aforementioned
thermo-well tube. However, the characteristics such as acid resistance, corrosion
resistance, etc. are not required to the material for the junction portion because the
junction portion cannot make a direct contact with the reactive substance which the
thermo-well tube is in contact with. The junction portion preferably has thermal
resisting property, cold resisting property and high heat conductivity, so as to
accurately measure the temperature.
In order to increase the heat conductivity, oil and the like may be used in the
junction portion. Further, the oil may be also injected into the thermo-well tube so to

WO 2006/135189 PCT/KR2006/002261
easily perform the heat-transfer from the catalyst layer to the sensors.
Preferably, the junction portion has a tube shape. Further, the junction portion has a
small inner diameter enough to hardly affect the heat transfer.
The junction portion preferably has an outer diameter equal to or less than 90% of
the inner diameter of the thermo-well tube. If the outer diameter of the junction portion
is larger than 90% of the inner diameter of the thermo-well tube, the junction cannot
move in the event that the thermo-well tube is thermally deformed.
In FIG. 3, a reference numeral 51 indicates a distance between the sensors of two
thermocouples. If the distance is suitably adjusted, a damaged thermocouple may be
cut and removed and then a new thermocouple may be inserted into an extra space in
the junction portion, instead of a damaged thermocouple, even though one of the ther-
mocouples is damaged.
Specifically, the damaged portion of thermocouple is cut out and drawn out along
with a part of the junction portion. Then the other part of the usable portions of the
thermocouple and the junction portion are drawn out of the thermo-well tube. Next, a
new thermocouple is inserted into the rest of the cut junction portion attached to the
usable thermocouple and then pressure is applied to a portion of the junction portion
which does not overlap with the sensor, so that the junction portion is integrated with
the thermocouple. For example, if the thermocouple 1 of FIG. 3 has a problem of the
sensor, the junction portion 51 is cut at position near the thermocouple 1 and then the
new thermocouple is inserted into and integrated with the remaining portion 51 of the
junction portion.
FIG. 4 is a schematic view showing another variation of the temperature sensor in
the temperature measuring device according to the present invention. The two junction
portions 62 and 63 are connected by using a connection member 61, for example a
wire, which has an excellent elasticity and ductility.
In FIG. 4, a reference numeral 64 indicates a distance between two junction
portions in which sensors of the thermocouples are respectively embedded. If the
distance is suitably adjusted, the connection member 61 is cut at a suitable portion
thereof and then the connection member 61 can be connected to a new junction
portion.
Industrial Applicability
The temperature measuring device according to the present invention can easily
measure the temperature while being moved by using tension, in comparison with the
conventional device. Further, it is possible to avoid affecting a temperature monitoring
system due to damage thereof, and to easily replace the damaged measuring device
with another one.

8
WO 2006/135189 PCT/KR2006/002261
In addition, since the temperature measuring device according to the present
invention includes at least two temperature detecting sensors or at least two
temperature measuring means, it is possible to continuously measure the temperature
without replacement of the damaged element even though one of the temperature
detecting sensors or the temperature measuring means is damaged. Further, the
temperature measuring device has an advantage in that the temperature detecting
sensor or the temperature measuring means can be easily replaced, maintained and
repaired.
Although a preferred embodiment of the present invention has been described for il-
lustrative purposes, those skilled in the art will appreciate that various modifications,
additions and substitutions are possible, without departing from the scope and spirit of
the invention as disclosed in the accompanying claims.

WO 2006/135189 PCT7KR2006/002261
Claims
A temperature measuring device comprising:
a thermo-well tube; and
a cable or wire type temperature measuring means which is installed in a thermo-
well tube,
wherein temperature measuring means has temperature detecting sensors
disposed at an intermediate portion thereof, and
the temperature detecting sensors can be moved axially in the thermo-well tube
by applying tension to both ends of the cable or wire type temperature measuring
means.
The temperature measuring device as claimed in claim 1, which further
comprises pulleys installed at outside of openings formed at both ends of the
thermo-well tube, respectively,
wherein the pulleys are used when the tension is applied to the cable or wire type
temperature measuring means.
The temperature measuring device as claimed in claim 1, wherein the cable or
wire type temperature measuring means has flexibility.
The temperature measuring device as claimed in claim 1, wherein the cable or
wire type temperature measuring means includes a thermocouple or a resistance
temperature detector.
The temperature measuring device as claimed in claim 1, wherein the thermo-
well tube is filled with oil.
The temperature measuring device as claimed in claim 1, wherein the
temperature detecting sensors include a pair of temperature sensors which are
contained in a junction portion and connected to each other, or a pair of
temperature sensors which are respectively contained in each junction portion
and connected to each other by a connection portion.
The temperature measuring device as claimed in claim 6, wherein the junction
portions are in a tube type.
The temperature measuring device as claimed in claim 6, wherein the junction
portions are filled with oil.
The temperature measuring device as claimed in claim 6, wherein the junction
portions have an outer diameter which is equal to or less than 90% (hat of an
inner diameter of the thermo-well tube.
A reaction tube in which the temperature measuring device claimed in any one
claim of 1 to 9 is disposed axially.
A reactor comprising at least one temperature measuring device claimed in any

10
WO 2006/135189 PCT/KR2006/002261
one claim of 1 to 9.
A reactor comprising at least one reaction tube claimed in claim 10.

Disclosed is a temperature measuring device. The
temperature measuring device includes: a thermo-well
tube; and a cable or wire type temperature measuring
means which is installed in a thermo-well tube, wherein
temperature measuring means has temperature detecting
sensors disposed at an intermediate portion thereof, and
the temperature detecting sensors can be moved axially
in the thermo-well tube by applying tension to both ends
of the cable or wire type temperature measuring means.
The present invention also provides a reaction tube in
which the temperature measuring device is disposed
axially, and a reactor including at least one
temperature measuring device or reaction tube as
described above.