JPS645216Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention can quickly and accurately detect the temperature distribution in the height direction inside a distillation column in a petroleum plant or the temperature distribution in the thickness direction inside a furnace wall, and is extremely easy to handle. This invention relates to a multi-point temperature sensor consisting of a plurality of sheathed thermocouples.

Conventionally, a multi-point temperature sensor consisting of multiple sheathed thermocouples has, for example, a plurality of sheathed thermocouples with hot junctions formed at their tips, arranged with their tips offset from each other in the length direction. Also known is a very simple structure in which the wires are tied at appropriate locations in the length direction with bands or the like. This multi-point temperature sensor is extremely easy to manufacture and has excellent flexibility and thermal responsiveness because the outer diameter of the entire structure can be made small.Furthermore, because the overall heat capacity is small, the temperature sensor However, on the other hand, when detecting the temperature distribution in the thickness direction inside a solid, for example inside a furnace wall, it is difficult to detect each temperature. Since the cross-sectional configurations of the contacts are different, there is a difference in the heat receiving conditions from the axial direction and the circumferential direction at each hot junction, that is, the temperature measurement conditions, making it impossible to detect accurate temperature distribution, and the mutual relationship between the sheathed thermocouples. but,
Since it is in a floating state except for the binding part, it lacks integrity as a whole, so if it is used by bending it or inserting it into a curved hole, it not only becomes complicated to handle, but also the thermoelectric Since the heat transfer between the pairs is not uniform and steady, there are differences in the heat reception conditions from the object to be measured in each sheathed thermocouple, resulting in a decrease in temperature measurement accuracy. Since the paired thermocouple wires are arranged in parallel, they are affected by electromagnetic induction interference from the outside, resulting in temperature measurement errors. It had the following problems. In addition, as an earlier application, for example,
-The temperature distribution detection sensor described in Publication No. 105140 is
A plurality of sheathed thermocouples are placed at different locations in the length direction, and a dummy made of the same material as the sheathed thermocouple is connected to the tip of each temperature sensing section. In addition to aligning the cutting edge of
These sheathed thermocouples are arranged parallel to each other without contacting each other via an insulating material and housed inside a jacket sheath. Although the temperature conditions are the same and accurate temperature distribution can be detected, on the other hand,
Not only does it have a large outer diameter and lack flexibility, but it also has a large heat capacity and high resistance to heat transfer to the temperature sensing part, resulting in a lack of thermal responsiveness. In addition, it is inconvenient to apply the temperature measurement target to something with a small heat capacity, such as a gas body. There is a problem.

The purpose of the present invention is to eliminate each of the drawbacks of the conventional sensors mentioned above and to provide a multi-point temperature sensor that has the characteristics thereof. A plurality of sheathed thermocouples each having a hot junction formed at an arbitrary location are arranged so that their tips are aligned and the hot junctions are shifted from each other in the length direction, and they are twisted together. This is a multi-point temperature sensor that is characterized by:

The present invention will be explained below based on the drawings illustrating the invention.
FIG. 1 is an external perspective view of an embodiment of the present invention, and FIGS. 2 and 3 are a sectional view and a developed sectional view taken along the line A-A in FIG. A hot junction 4 is formed by joining arbitrary parts on the wires 2 and 3, and the tips are closed 5 in contact with the thermocouple wires 2 and 3 or in a non-contact state as shown in the figure. Each sheathed thermocouple 1... is arranged with its leading edge aligned and with the hot junctions 4 shifted from each other in the length direction,
They are twisted together 6, and at this time,
The mutual relationship between the thermocouple wires 2 and 3 can be formed in a state (hereinafter referred to as a "twisted shape") 7 in which the thermocouple wires 2 and 3 are twisted together or intertwined in a non-contact state (hereinafter referred to as a "twisted shape"), as shown in the figure. In order to prevent the ends of the twisted pair 6 from unraveling, it is preferable to weld or otherwise secure them to each other before or after twisting. In addition to using each sheath type thermocouple as shown in the figure, for example, as described in the above-mentioned Japanese Utility Model Publication No. 55-105140, a dummy may be connected to the tip of the sheath type thermocouple. Of course, it is possible to use a thermocouple with a single sheath type structure as shown in the figure, since there is no joint in the length direction. This method is preferable in terms of measurement accuracy because the heat transfer is uniform and steady.

If the multi-point temperature sensor having the above structure is further reduced in diameter as illustrated in the sectional view of FIG. 4, the outer diameter of the entire structure can be made smaller and the thermal response can be improved. By eliminating the internal space 8 formed between the contact surfaces of each sheathed thermocouple 1 as shown in FIG. 2, the adverse effect of air convection within the internal space 8 on measurement accuracy is eliminated. It is possible. Further, as illustrated in FIG. 5, each sheathed thermocouple 1 is surrounded by a covering member 9 braided with thin wires made of air permeable and flexible heat-resistant steel such as stainless steel. This has the advantage of preventing mechanical damage to each sheathed thermocouple without impairing the heat receiving efficiency of the sheathed thermocouples 1.

As described above, the multipoint temperature sensor of the present invention has an extremely small outer diameter, so it has a small heat capacity, excellent thermal response, and good flexibility. The temperature conditions are the same, and accurate temperature distribution can be detected.

In addition, since the whole is constructed by twisting each sheathed thermocouple together, the heat receiving conditions for each sheathed thermocouple from the axial direction and the outer circumferential direction are steady and stable, resulting in good temperature measurement accuracy. Not only can the sensor be maintained at a
It has the effect of having high mechanical strength. Furthermore, since the thermocouple wires of each sheath type thermocouple are twisted together, the effects of electromagnetic induction interference can be eliminated.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an embodiment of the multi-point temperature sensor of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a developed explanation of the sensor of the embodiment shown in Fig. 1. 4 is a sectional view showing the state of the multi-point temperature sensor according to the present invention after diameter reduction processing, and FIG. 5 is a partially cutaway external perspective view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Sheath type thermocouple, 2, 3... Thermocouple wire, 4... Hot junction, 5... Closure, 6... Twisting, 7... Twisted portion, 8... Internal space, 9...
...Covered member.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a multi-point temperature sensor consisting of sheathed thermocouples, a plurality of sheathed thermocouples each having a hot junction formed at an arbitrary position in the length direction, each with its tip end A multi-point temperature sensor, characterized in that the hot junctions are arranged in alignment and offset from each other in the length direction, and are twisted together. (2) The multi-point temperature sensor according to claim 1, which is characterized in that the entire diameter is reduced. (3) A multi-point system according to claim 1 or 2 of the utility model registration claim, characterized in that the outside of a plurality of sheathed thermocouples is surrounded by a covering member having air permeability and flexibility. temperature sensor. (4) Utility model registration claim 1, 2, or 3, characterized in that each sheathed thermocouple has a thermocouple wire twisted inside it in a non-contact manner. Multi-point temperature sensor.