Double-function type high-temperature thermocouple

Abstract

The invention discloses a difunctional high-temperature thermocouple, which comprises a K-type thermocouple and a B-type thermocouple which are arranged in parallel, the K-type thermocouple and the B-type thermocouple jointly penetrate through the upper protection tube, the fixing ring and the flange connector from top to bottom in sequence and stretch into the corundum tube lining. The outer side of the corundum tube lining is sleeved with a protective sleeve. The dual-function high-temperature thermocouple is composed of the K-type thermocouple and the B-type thermocouple, and is wide in application range, high in safety, easy and convenient to operate and high in measurement efficiency. Moreover, according to the high-temperature thermocouple, armored sealing is adopted at the compression bolts, winding type gasket sealing and sleeve sealing are arranged at the connection positions of the movable bolts, and the electrical interfaces are two 1 / 2 'NPT (F) explosion-proof cable sealing joints, so that the sealing performance is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermocouples, and particularly to a high-temperature thermocouple with a dual-functional model. Background Art

[0002] A thermocouple is a temperature-measuring element commonly used in temperature-measuring instruments. It directly measures temperature, converts the temperature signal into a thermoelectromotive force signal, and converts it into the temperature of the measured medium through an electrical instrument (secondary instrument). The shapes of various thermocouples are often extremely different due to requirements, but their basic structures are roughly the same. They are usually composed of main parts such as thermal electrodes, insulating sleeve protection tubes, and junction boxes, and are usually used in conjunction with display instruments, recording instruments, and electronic regulators. In some special occasions, such as chemical plants, smelters, power plants, cement plants, etc., ordinary thermocouples are extremely easy to damage. Therefore, high-temperature thermocouples must be used in these occasions.

[0003] The models of high-temperature thermocouples mainly include K-type, S-type, B-type, E-type, J-type, N-type, T-type, etc. Among them, the K-type thermocouple is also called nickel-chromium-nickel-silicon thermocouple, which is the most widely used one among base-metal thermocouples. It has the advantages of good linearity, large thermoelectromotive force, high sensitivity, good stability and uniformity, and strong oxidation resistance. It is suitable for oxidizing inert atmospheres, but not suitable for reducing or reducing-oxidizing alternating atmospheres and vacuums at high temperatures. The S-type thermocouple is usually called single platinum-rhodium thermocouple, which belongs to precious-metal thermocouples. The positive electrode is a platinum-rhodium alloy, and the negative electrode is platinum. The operating temperature is generally 1200 - 1500 °C, and it has the advantage of good physical and chemical stability. It is usually used for high-temperature measurements with high accuracy requirements. The B-type thermocouple: usually called double platinum-rhodium thermocouple, which belongs to precious-metal thermocouples, and the operating temperature is below 1800 °C, and it has the advantages of good stability and high accuracy.

[0004] However, the above high-temperature thermocouples are all of single-functional models, with limited application ranges and unable to meet the usage requirements in complex environments. For example, in the gasifier of the coal chemical industry, the temperature measurement usually first uses a K-type preheating thermocouple during the furnace drying process from room temperature to 800 °C. When the temperature rises to 800 °C, another B-type high-temperature thermocouple is replaced to continue the high-temperature measurement process, which leads to many problems such as poor safety, cumbersome operation, and low measurement efficiency. Therefore, it is necessary in this field to design and develop a high-temperature thermocouple that can integrate multiple functional models. Summary of the Invention

[0005] The object of the present invention is to provide a high-temperature thermocouple with a dual-functional model.

[0006] To achieve the above object, the technical solution adopted by the present invention is specifically as follows:

[0007] A dual-functional high-temperature thermocouple model includes a K-type thermocouple and a B-type thermocouple arranged side by side; the K-type thermocouple and the B-type thermocouple jointly pass through an upper protection tube, a fixing ring, and a flange interface from top to bottom, and extend into the corundum tube lining; a protection sleeve is sleeved outside the corundum tube lining.

[0008] Among them, a reinforcing tube is sleeved outside the upper part of the protection sleeve, and the upper part of the reinforcing tube extends into the central hole of the flange and the outer wall of the reinforcing tube is welded to the flange.

[0009] Among them, the cross-section of the central hole of the flange is T-shaped, and the upper hole diameter is larger than the lower hole diameter; among them, the upper hole diameter of the central hole of the flange is equal to the lower outer diameter of the flange interface, and the lower hole diameter of the central hole of the flange is equal to the outer diameter of the reinforcing tube; the lower part of the flange interface is embedded in the central hole of the flange, and the outer wall of the flange interface is welded to the flange.

[0010] Among them, the cross-section of the central hole of the flange interface is T-shaped, and the upper hole diameter is larger than the lower hole diameter; the cross-section of the fixing ring is inverted T-shaped, and the lower outer diameter of the fixing ring is smaller than the upper hole diameter of the central hole of the flange interface. The lower part of the fixing ring is placed in the central hole of the flange interface. A wound gasket is provided between the lower bottom surface of the fixing ring and the step of the central hole of the flange interface; a movable bolt is sleeved outside the fixing ring, and the movable bolt is threadedly connected to the upper side wall of the central hole of the flange interface.

[0011] Among them, a groove is provided on the bottom surface of the upper protection tube; the top of the fixing ring extends into the groove of the upper protection tube and is welded to the upper protection tube.

[0012] Among them, the cross-section of the central hole of the upper protection tube is T-shaped, and the upper hole diameter is larger than the lower hole diameter; a sealing ring and a gasket are provided at the step of the central hole of the upper protection tube, and a compression bolt is provided above the sealing ring and the gasket. The compression bolt is threadedly connected to the inner wall of the central hole of the upper protection tube.

[0013] Among them, the upper part of the upper protection tube extends into the lower interface of the junction box, and the upper protection tube is fixed to the lower interface of the junction box by a nut.

[0014] Among them, two electrical interfaces are provided on the junction box. The electrical interfaces are of the 1 / 2"NPT(F) type and are equipped with explosion-proof cable gland joints.

[0015] Among them, the thermocouple wires of the K-type thermocouple and the B-type thermocouple are connected to the wiring terminals in the junction box and fixed by screws.

[0016] Among them, the part between the bottom surface of the lower interface of the junction box and the lower bottom surface of the flange is the extension section, and the part between the lower bottom surface of the flange and the bottom surface of the protective sleeve is the insertion section.

[0017] Compared with the prior art, the outstanding effect of the present invention lies in:

[0018] The dual-functional high-temperature thermocouple of the present invention is composed of a K-type thermocouple and a B-type thermocouple, with a wide range of applications, strong safety, simple operation, and high measurement efficiency. Moreover, the high-temperature thermocouple adopts armored sealing at the compression bolt, and installs a spiral wound gasket seal and sleeve seal at the movable bolt connection. The electrical interface is two 1 / 2"NPT(F) with explosion-proof cable gland, which greatly improves the sealing performance.

[0019] The following further describes the dual-functional high-temperature thermocouple of the present invention in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the dual-functional high-temperature thermocouple.

[0021] Among them, 1-K-type thermocouple, 2-B-type thermocouple, 3-upper protection tube, 4-fixed ring, 5-flange interface, 6-corundum tube lining, 7-protective sleeve, 8-reinforcing tube, 9-movable bolt, 10-spiral wound gasket, 11-flange, 12-junction box, 13-compression bolt, 14-electrical interface. Specific Embodiments

[0022] As Figure 1 shown, a dual-functional high-temperature thermocouple includes a K-type thermocouple 1 and a B-type thermocouple 2 arranged in parallel; the K-type thermocouple 1 and the B-type thermocouple 2 together pass through the upper protection tube 3, the fixed ring 4 and the flange interface 5 from top to bottom in sequence, and extend into the corundum tube lining 6; a protective sleeve 7 is sleeved outside the corundum tube lining 6.

[0023] A reinforcing tube 8 is sleeved outside the upper part of the protective sleeve 7, and the upper part of the reinforcing tube 8 extends into the central hole of the flange 11 and the outer wall of the reinforcing tube 8 is welded to the flange 11.

[0024] The cross-section of the central hole of the flange 11 is T-shaped, and the upper aperture is larger than the lower aperture; among them, the upper aperture of the central hole of the flange 11 is equal to the lower outer diameter of the flange interface 5, and the lower aperture of the central hole of the flange 11 is equal to the outer diameter of the reinforcing tube 8; the lower part of the flange interface 5 is embedded in the central hole of the flange 11, and the outer wall of the flange interface 5 is welded to the flange 11.

[0025] The center hole of the flange interface 5 has a T-shaped cross-section, and the upper hole diameter is larger than the lower hole diameter; the cross-section of the fixing ring 4 is an inverted T-shape, and the lower outer diameter of the fixing ring 4 is smaller than the upper hole diameter of the center hole of the flange interface 5, the lower part of the fixing ring 4 is placed in the center hole of the flange interface 5, and a winding gasket 10 is provided between the lower bottom surface of the fixing ring 4 and the step of the center hole of the flange interface 5; the outer side of the fixing ring 4 is provided with a movable bolt 9, and the movable bolt 9 is connected to the upper side wall of the center hole of the flange interface 5 by threads.

[0026] The bottom surface of the upper protective tube 3 is provided with a groove; the top of the fixing ring 4 extends into the groove of the upper protective tube 3 and is welded to the upper protective tube 3 .

[0027] The cross section of the center hole of the upper protection tube 3 is T-shaped, and the upper hole diameter is larger than the lower hole diameter; a sealing ring and a gasket are provided at the step of the center hole of the upper protection tube 3, and a clamping bolt 13 is provided above the sealing ring and the gasket, and the clamping bolt 13 is connected to the inner wall of the center hole of the upper protection tube 3 through a thread. After repeated tests, if the sealing point of the gasket is placed on the flange edge and the lower part of the flange, the temperature is high and not durable enough; when it is set at the lower part of the junction box, the temperature is normal temperature, so that the sealing point can be used for a long time, and there will be no uneven installation caused by frequent replacement.

[0028] The upper portion of the upper protection tube 3 extends into the lower interface of the junction box 12 , and the upper protection tube 3 and the lower interface of the junction box 12 are fixed together by a nut.

[0029] The junction box 12 is provided with two electrical interfaces 14, which are 1 / 2" NPT (F) type with explosion-proof cable sealing joints. One of the electrical interfaces 14 is used to connect a K-type thermocouple, and the other is used to connect a B-type thermocouple.

[0030] The wires of the K-type thermocouple 1 and the B-type thermocouple 2 are connected to the wiring terminals in the junction box 12 and fixed by screws.

[0031] The junction box 12 is a 304SS stainless steel junction box.

[0032] The portion between the bottom surface of the lower interface of the junction box 12 and the lower bottom surface of the flange 11 is an extension section with a length of 200 mm; the portion between the lower bottom surface of the flange 11 and the bottom surface of the protective sleeve 7 is an insertion section with a length of 900 mm.

[0033] The K-type thermocouple is Class I, the armor sheath is made of Inconel600, the minimum diameter of the K-type thermocouple wire is φ0.9mm, the heat shrink tube isolates the thermocouple wire, the reference end is blown with sand to a depth of about 10mm, and epoxy glue is injected.

[0034] B-type thermocouple is covered with PTFE isolating wire, adopts two-hole corundum insulating tube, and has a glue-filled sleeve on the upper part, which is filled with ES568 epoxy glue. The pressure detection is 1.0Mpa.

[0035] The flange adopts ASME B16.5 150#2"RF, and the flange material is 316SS. The protective sleeve 7 adopts imported C799 high-purity corundum tube. The material of the reinforcement tube 8 is GH3039 alloy. The movable bolt is M40×1.5. The metal belt of the spiral wound gasket is made of 304 steel, and the filling material is flexible graphite tape.

[0036] The specific steps of the method for making the dual-function high-temperature thermocouple are as follows:

[0037] (1) inserting a corundum tube lining into the inner hole of the protective sleeve; wherein the outer surface of the corundum tube lining is wrapped with asbestos rope and glue is added to fix the protective sleeve and the corundum tube lining into shape;

[0038] (2) Install the flange interface into the center hole of the flange;

[0039] (3) Insert the reinforcing pipe into the center hole of the flange, and make the top surface of the reinforcing pipe and the bottom surface of the flange interface butt together;

[0040] (4) Install a wound gasket at the step of the center hole of the flange interface, then install the fixing ring into the center hole of the flange interface, and fix the flange interface and the fixing ring together with movable bolts;

[0041] (5) Fix the connection gap between the center hole of the flange and the reinforcement pipe after forming, and weld them; and connect and weld the upper protection pipe and the fixing ring together;

[0042] (6) Insert the fixed protective sleeve into the inner hole of the reinforcement pipe, and then wrap the outer side of the protective sleeve with asbestos rope to fix it into a whole;

[0043] (7) Insert the K-type thermocouple and the B-type thermocouple side by side from top to bottom through the upper protective tube, the fixing ring and the flange interface, and extend them into the inner lining of the corundum tube;

[0044] (8) The upper protective tube is fixed to the terminal box end by a nut, wherein a sealing ring and a gasket are provided at the step of the center hole of the upper protective tube, and a clamping bolt is provided above the sealing ring and the gasket, and the clamping bolt is connected to the upper protective tube 3 by threads;

[0045] (9) Open the junction box cover, connect the wires in the junction box to the terminal inside the junction box, and fix them with screws.

[0046] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A dual-function high-temperature thermocouple, characterized in that: The invention comprises a K-type thermocouple (1) and a B-type thermocouple (2) which are arranged in parallel; the K-type thermocouple (1) and the B-type thermocouple (2) pass through an upper protective tube (3), a fixing ring (4) and a flange interface (5) from top to bottom in sequence, and extend into a corundum tube lining (6); a protective sleeve (7) is sleeved on the outer side of the corundum tube lining (6).

2. The dual-function high-temperature thermocouple according to claim 1, characterized in that: A reinforcing tube (8) is sleeved on the outer side of the upper part of the protective sleeve (7), the upper part of the reinforcing tube (8) extends into the central hole of the flange (11), and the outer wall of the reinforcing tube (8) is welded to the flange (11).

3. The dual-function high-temperature thermocouple according to claim 2, characterized in that: The center hole of the flange (11) has a T-shaped cross section, and the upper hole diameter is larger than the lower hole diameter; wherein the upper hole diameter of the center hole of the flange (11) is equal to the lower outer diameter of the flange interface (5), and the lower hole diameter of the center hole of the flange (11) is equal to the outer diameter of the reinforcing pipe (8); the lower part of the flange interface (5) is embedded in the center hole of the flange (11), and the outer wall of the flange interface (5) is welded to the flange (11).

4. The dual-function high-temperature thermocouple according to claim 3, characterized in that: The center hole of the flange interface (5) has a T-shaped cross section, and the upper hole diameter is larger than the lower hole diameter; the fixing ring (4) has an inverted T-shaped cross section, and the lower outer diameter of the fixing ring (4) is smaller than the upper hole diameter of the center hole of the flange interface (5); the lower part of the fixing ring (4) is placed in the center hole of the flange interface (5), and a winding gasket (10) is provided between the lower bottom surface of the fixing ring (4) and the step of the center hole of the flange interface (5); the outer side of the fixing ring (4) is sleeved with a movable bolt (9), and the movable bolt (9) is connected to the upper side wall of the center hole of the flange interface (5) by threads.

5. The dual-function high-temperature thermocouple according to claim 4, characterized in that: The bottom surface of the upper protective tube (3) is provided with a groove; the top of the fixing ring (4) extends into the groove of the upper protective tube (3) and is welded to the upper protective tube (3).

6. The dual-function high-temperature thermocouple according to claim 5, characterized in that: The center hole of the upper protective tube (3) has a T-shaped cross section, and the upper hole diameter is larger than the lower hole diameter; a sealing ring and a gasket are provided at the step of the center hole of the upper protective tube (3), and a clamping bolt (13) is provided above the sealing ring and the gasket, and the clamping bolt (13) is connected to the inner wall of the center hole of the upper protective tube (3) through a thread.

7. The dual-function high-temperature thermocouple according to claim 6, characterized in that: The upper portion of the upper protective tube (3) extends into the lower interface of the junction box (12), and the upper protective tube (3) and the lower interface of the junction box (12) are fixed together by a nut.

8. The dual-function high-temperature thermocouple according to claim 7, characterized in that: The junction box (12) is provided with two electrical interfaces (14), and the electrical interfaces (14) are 1 / 2" NPT (F) type and have explosion-proof cable sealing joints.

9. The dual-function high-temperature thermocouple according to claim 8, characterized in that: The wires of the K-type thermocouple (1) and the B-type thermocouple (2) are connected to the wiring terminals in the junction box (12) and fixed by screws.

10. The dual-function high-temperature thermocouple according to claim 9, characterized in that: The portion between the bottom surface of the lower interface of the junction box (12) and the lower bottom surface of the flange (11) is an extension section, and the portion between the lower bottom surface of the flange (11) and the bottom surface of the protective sleeve (7) is an insertion section.

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