JP4958701B2 - Temperature measuring cable for coal silo and manufacturing method thereof - Google Patents

Description

  The present invention relates to a temperature measurement cable for managing the internal temperature of a coal silo installed in a coal-fired power plant or the like, and a method for manufacturing the same.

  In the coal power generation system, coal landed with a coal-lifting machine is once charged from the top of the coal silo and stored in the silo. Electric power is generated by generating high-pressure steam, rotating a turbine, and turning a generator directly connected to the turbine.

  Since the coal silo normally has a sealed structure to suppress dust scattering, a temperature increase due to coal oxidation may occur during coal storage.

  In order to detect the temperature rise, a temperature measuring cable is suspended from the top of the silo in the silo, and whether the temperature rise occurs in the silo by watching the temperature change in the silo detected by the temperature measuring cable. Is monitoring.

  For the purpose of preventing temperature rise, coal that exceeds the standard coal storage days is moved to an empty coal silo for air cooling, and water is sprayed or nitrogen is blown as necessary.

  As the temperature measuring cable, a cable in which a conducting wire having a plurality of temperature sensors is provided along a wire and the outer periphery thereof is covered with a polymer film is known (for example, see Patent Document 1).

  This type of temperature measuring cable is applied to a relatively small silo. For example, a large-sized coal silo with a coal storage amount of, for example, 30,000 t, uses a temperature measuring cable with higher strength.

  FIG. 4 shows the configuration of a temperature measuring cable currently used in a large coal silo. FIG. 4 (a) shows the appearance and FIG. 4 (b) shows the cross-sectional structure.

In both figures, the temperature measuring cable 50 has a resin tube 50b in which a plurality of temperature cables 50a are inserted disposed in the center, and a plurality of wire ropes 51 for providing strength are wound around the outer periphery thereof. It has a special structure.
JP-A-63-206617 (page (2), FIG. 2)

  However, although the temperature measuring cable 50 is reinforced with a wire rope, it has a disadvantage that it is frequently cut and has a short life.

  Therefore, when a load cell was attached to the temperature measuring cable 50 and the load acting on the temperature measuring cable 50 was analyzed, it was confirmed that a sudden load change occurred after the coal was received.

  As a result of investigating the cause of this sudden load change, when the mountain of coal collapses rapidly with the bottom of the temperature measuring cable 50 buried in the coal, the temperature measuring cable 50 cannot escape and receives excessive loads. Turned out to be.

  This excessive load occurs regardless of whether or not the lower end of the temperature measuring cable 50 is fixed. When the coal pile collapses rapidly, a load greater than the design load was applied to the temperature measuring cable 50. become.

  Further, when the cut portion of the temperature measuring cable 50 is examined, the core material at the center of the wire rope 51 is in a state of being unraveled because the strength is insufficient, and the load is applied to each wire rope 51. The fact that it does not act equally also causes the temperature measuring cable 50 to be cut.

  Therefore, even if the wire rope 51 wound around the outer periphery of the resin tube 50b is simply replaced with one having a high cutting load, the fundamental problem is not solved.

  On the other hand, for example, when a wire rope for hanging load having a high core material strength is used, the cutting load can be increased without unraveling. However, with this configuration, the temperature measurement cable must be routed around the wire rope, and the temperature measurement cable is cut when the temperature measurement cable directly contacts the coal.

  The present invention has been made in consideration of the problems of the conventional temperature measuring cable as described above, and does not cut even if an excessive load is applied due to a sudden collapse of the coal pile. A cable and a method for manufacturing the same are provided.

  The temperature measuring cable for coal silo of the present invention includes a wire rope, a plurality of thermocouples wired in the wire rope longitudinal direction along the outer surface of the wire rope, and the outside of the wire rope wired with a plurality of thermocouples. It is composed of a heat-shrinkable tube that is applied to the outer surface of the heat-shrinkable tube and an exterior material formed by weaving a linear or band-shaped metal material outside the heat-shrinkable tube.

  In the temperature measuring cable for coal silo, a sheathed thermocouple can be used as the thermocouple, and it is preferably fixed to the wire rope through a fixture with a slight slack.

  Moreover, it is preferable to use a rubber-based tube as the heat-shrinkable tube because it can be completely adhered.

  Moreover, when the said heat-shrinkable tube is comprised from a several layer, since a load can be disperse | distributed by each layer, it is preferable when raising an intensity | strength.

  Further, if a wire blade in which a plurality of wire strands are arranged in parallel and machine braided is used as the exterior material, the exterior that is the outermost layer of the temperature measuring cable can have strength and flexibility.

  The method for producing a temperature measuring cable for coal silo according to the present invention is such that a plurality of thermocouples are wired along the wire rope in the longitudinal direction of the wire rope, and each wired thermocouple is fixed with a fixture at a predetermined interval. Put a heat-shrinkable tube on the outside of the wire rope where the thermocouple is wired, and heat-shrink the tube so that it is in close contact with the wire rope, and weave a linear or strip-shaped metal material over the entire outer circumference of the shrunk tube Thus, the gist is to form a flexible exterior.

  In the above manufacturing method, when tension is applied to the temperature measuring cable for coal silo in which the exterior is formed, the diameter of the exterior knitted by the tension is reduced, so that the wire rope and The thermocouple, the tube, and the exterior can be integrated.

  According to the present invention, it is possible to provide a temperature measuring cable for a coal silo that is not cut even when an excessive load is applied due to a sudden collapse of a coal mine.

  Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 shows a configuration of a coal silo to which a temperature measuring cable for coal silo of the present invention is applied.

  In the figure, the coal silo 1 has a height of 46.5 m and an inner diameter of 35 m, for example, and has a large size capable of storing 30,000 t of coal.

2 is a silo air shut-off device, 3 is a water spray fire extinguishing device in the silo, 4 is a temperature measuring cable, 5 is an N ₂ blowing device, 6 is a center cone, 7 is a delivery chain conveyor, 8 is an air shut-off device under the silo, 9 Is a lower silo conveyor. In addition, the arrow shown with the broken line has shown the coal moving direction in a silo in the figure.

  FIG. 2 shows the temperature measuring cable 4 in an enlarged manner.

  In the figure, reference numeral 10 is a commercial wire rope for φ16 mm, for example, a fiber impregnated with a lubricant is used as a core 10a, and six strands 10b are combined around the core 10a. It is comprised by uniting the strand 10c which consists of a hard steel wire of this book. In addition, the diameter of the wire rope 10 can be selected in the range of φ12.5 to 16 mm.

  Further, the length L1 of the wire rope 10 is a length that can substantially cover the height of the coal silo, and one end of the wire rope 10 is folded in a loop shape and bound by a tallit clamp 11. Further, a U-shaped reinforcing metal fitting 13 is attached to the loop portion 12 formed by folding, and the loop portion 12 is fixed to a suspension shaft (not shown) provided at the top of the coal silo. The Note that the other end of the wire rope 10 is subjected to the anti-separation terminal treatment.

  Reference numeral 14 denotes a sheathed thermocouple that is wired along the wire rope 10 in the longitudinal direction of the wire rope.

  Each sheath thermocouple 14 can be used, for example, with a strand diameter of 0.32 mm coated with a vinyl resin, and its operating temperature range is -20 to + 90 ° C.

  Reference numeral 15 denotes a protective pipe through which the sheath thermocouple 14 is inserted. The protective pipe 15 prevents the loop portion 12 of the wire rope 10 and the sheath thermocouple 14 from rubbing and breaking.

  The sheathed thermocouple 14 passed through the protective pipe 15 is wired along the wire rope 10. Specifically, the sheathed thermocouple 14 is wired along the outer peripheral surface of the wire rope 10 and arranged at substantially equal intervals when viewed from the cross section. The plurality of wired sheathed thermocouples 14 can measure a plurality of measurement sites in the height direction of the coal silo 1 by individually changing the length to the tip thereof.

  These wired sheath thermocouples 14 are fixed to the wire rope 10 by clips (fixers) 16. At this time, each sheath thermocouple 14 is fixed with some slack, and can be freely displaced between the clips 16 to some extent.

  Reference numeral 17 denotes a thermocouple fixing tube attached to the outside of the sheath thermocouple 14.

  This thermocouple fixing tube 17 is composed of a multi-layer of a first layer tube 17a and a second layer tube 17b. The first layer tube 17a is composed of a heat-shrinkable rubber tube having an inner diameter before shrinkage of, for example, 25 mm and a thickness of 2 mm. Thus, the second-layer tube 17b is composed of a heat-shrinkable rubber tube having an inner diameter before shrinkage of, for example, 30 mm and a thickness of 2 mm.

  The thermocouple fixing tube is made of ethylene propylene rubber and shrinks when heated to 120 ° C or higher. Use an industrial dryer, gas burner, infrared heater, electric heater, etc. as the heat source for heating. Can do.

  The thermocouple fixing tube 17 is fixed with the sheath thermocouple 14 in close contact with the outer peripheral surface of the wire rope 10.

  A flexible exterior (exterior material) 18 is applied to the outside of the thermocouple fixing tube 17.

  As this flexible exterior 18, there are a wire blade obtained by mechanically braiding several to several dozen wires in parallel, and a ribbon blade obtained by knitting a strip-like plate material in a bamboo basket shape. Any flexible sheath 18 can be used.

  However, it is preferable to use a wire blade that is excellent in bending resistance and pressure resistance because the ribbon blade is difficult to cope with continuous repeated movement. A wire blade having a thickness of 0.3 mm was used.

  Next, a method for manufacturing the temperature measuring cable 4 will be described.

  First, the wire rope 10 is developed and arranged straight.

  Next, the sheath thermocouple 14 is disposed along the wire rope 10 and fixed to the outer peripheral surface of the sheath thermocouple 14 with a clip 16 at a predetermined interval.

  Next, the first layer tube 17 a is put on the outer side of the wire rope 10 provided with the sheath thermocouple 14, and the first layer tube 17 a is contracted and closely adhered to the wire rope 10 by rolling with a gas burner. The sheath thermocouple 14 is sandwiched and fixed between the wire rope 10 and the contracted first layer tube 17a.

  Next, the second layer tube 17b is put on the outer side of the first layer tube 17a, and similarly, the second layer tube 17b is contracted and closely adhered to the first layer tube 17a by rolling with a gas burner.

  In this way, the thermocouple fixing tube 17 having two layers is formed. The two-layer thermocouple fixing tube 17 has a contracted thickness of about 2 mm.

  When connecting the first-layer tubes 17a to each other, the tube of the same size as the first-layer tube 17a or an equivalent product of a size higher than the first-layer tube 17a is used as a cover tube and straddles each end of the first-layer tube 17a. It arrange | positions so that it may peel, it is made to shrink | contract by heating, and what is necessary is just to integrate with each edge part of the 1st layer tube 17a which opposes. The same applies when connecting the second-layer tube 17b.

  Next, a wire blade is knitted on the entire outer peripheral surface of the thermocouple fixing tube 17, and the flexible sheath 18 is attached to the temperature measuring cable 4.

  When the temperature measuring cable 4 to which the flexible sheath 18 is attached in this way is suspended from the top of the coal silo 1, a tension is applied in the length direction by the weight of the temperature measuring cable 4, and the flexible sheath 18 that receives the tension is applied. Is narrowed in the direction of reducing the knitted diameter. Thereby, the flexible outer casing 18 can be in close contact with the thermocouple fixing tube 17, and the self-locking effect of the flexible outer casing 18 can be obtained.

  The thermocouple fixing tube 17 is made of a rubber-based material, so that the thermocouple fixing tube 17 maintains elasticity even after shrinking. When the flexible outer casing 18 is squeezed and the diameter is reduced, the thermocouple fixing tube 17 is Since it is slightly pressed, it can be surely adhered.

  FIG. 3 shows the structure of the temperature measuring cable 4 manufactured by the above manufacturing method, wherein (a) shows the appearance and (b) shows the cross section.

  In FIG. 5B, a first layer tube 17a is attached to the outside of the wire rope 10, and a second layer tube 17b is attached to the outside of the first layer tube 17a. A flexible exterior 18 is attached to the outside. In addition, in the drawing, the flexible outer casing 18 is drawn with a perfect circle so that the cross-sectional structure can be easily understood, but in actuality, it is formed along the contour of the second-layer tube 17b.

  In a coal silo that receives and discharges coal 60 times a year, when a conventional temperature measurement cable is used, replacement of the temperature measurement cable by cutting has occurred about 20 times. This is the rate at which the temperature measuring cable is exchanged by receiving and dispensing three times, and the idea that the temperature measuring cable is to be cut has been the common belief. If cutting occurs frequently in this way, a large amount of money and time must be spent repairing the temperature measuring cable.

  On the other hand, the temperature measuring cable 4 of the present invention devised with the goal of zero cutting is not cut even after one year has passed since it was installed in the coal silo 1 where the inside is not disclosed. In the flexible outer casing 18, no breakage of the strands occurred. Thus, the number of cuts of the temperature measuring cable 4 can be reduced to zero, and as a result, the cost can be significantly reduced.

  In addition, since temperature management can be continuously performed using the same temperature measuring cable 4, it becomes possible to stabilize temperature management.

It is sectional drawing which shows the structure of the coal silo to which the temperature measuring cable which concerns on this invention is applied. It is explanatory drawing which shows the structure of the temperature measuring cable of this invention. (a) is an external view of the temperature measuring cable according to the present invention, and (b) is a cross-sectional view thereof. (a) is an external view of a conventional temperature measuring cable, and (b) is a transverse sectional view thereof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coal silo 2 Silo air shut-off device 3 Silo water spray fire extinguishing equipment 4 Temperature measuring cable 5 N ₂ blowing equipment 6 Center cone 7 Discharge conveyor 8 Silo lower air shut-off device 9 Silo lower conveyor 10 Wire rope 11 Tallit clamp 12 Loop Part 13 Reinforcing metal fitting 14 Sheath thermocouple 15 Protective pipe 16 Clip 17 Thermocouple fixing tube 17a First layer tube 17b Second layer tube 18 Flexible exterior

Claims (7)

Wire rope,
A plurality of thermocouples wired in the wire rope longitudinal direction along the outer surface of the wire rope;
A heat-shrinkable tube attached to the outside of the wire rope wired with the plurality of thermocouples;
A coal silo temperature measuring cable comprising an exterior material formed by weaving a linear or belt-like metal material outside the heat-shrinkable tube.   The temperature measuring cable for a coal silo according to claim 1, wherein a sheathed thermocouple is used as the thermocouple, and is fixed to the wire rope via a fixture with a slight slack.   The temperature measuring cable for coal silo according to claim 1 or 2, wherein the heat-shrinkable tube has a rubber tube.   The temperature measuring cable for coal silo according to any one of claims 1 to 3, wherein the heat-shrinkable tube is composed of a plurality of layers.   The temperature measuring cable for coal silo according to any one of claims 1 to 4, comprising a wire braid obtained by mechanically braiding a plurality of wire strands arranged in parallel as the exterior material.   Multiple thermocouples are wired along the wire rope in the longitudinal direction of the wire rope, each wired thermocouple is fixed with a fixture at predetermined intervals, and heat shrinks to the outside of the wire rope where the thermocouple is wired A flexible sheath is formed by covering the outer peripheral surface of the tube, and making the tube tightly adhere to the wire rope by heating and shrinking, and braiding a linear or belt-like metal material over the entire outer peripheral surface of the shrinked tube. A method for manufacturing a temperature measuring cable for a coal silo.   Applying tension to the temperature measuring cable for coal silo in which the outer sheath is formed, reducing the diameter of the braided outer sheath by the tension, and integrating the wire rope, the thermocouple, the tube, and the outer sheath The manufacturing method of the temperature measuring cable for coal silos of claim | item 6.

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