Thermocouple protection tube suitable for materials easy to adhere to walls

Abstract

The utility model discloses a thermocouple protection tube suitable for materials easy to adhere to walls. The thermocouple protection tube comprises a reaction system used for placing a thermocouple tube and a film forming liquid injection system used for injecting film forming liquid into the thermocouple tube. A main body of the thermocouple tube is of a micropore sintered metal structure, and an anti-sticking film is formed on the outer wall of the thermocouple tube after the film forming liquid is injected into the main body of the thermocouple tube. According to the thermocouple protection tube provided by the utility model, adhesion of viscous materials can be avoided, periodic fluctuation of the system temperature is prevented, and the reaction temperature can be stably controlled.

Description

Technical Field

[0001] This utility model relates to a thermocouple protection tube suitable for materials that easily adhere to experimental equipment, belonging to the field of temperature detection technology for chemical equipment. Background Technology

[0002] In chemical reactions, the accurate and stable control of the reaction system's temperature directly affects the reaction results, such as the selectivity and quality of the target product. Since most materials in chemical systems are corrosive, temperature sensing elements—thermocouples—are typically installed in protective sheaths, usually made of ordinary stainless steel. If the viscosity of the materials in the system is low, ordinary stainless steel sheaths are sufficient for heat transfer and protection. However, if the material viscosity is high, it easily adheres to the thermocouple tube, affecting heat transfer and preventing the thermocouple from detecting the true system temperature. This is especially important when the thermocouple is the control thermocouple for the system temperature, forming a control loop with the heating equipment to maintain the system reaction temperature. Experimental setups are essential for new technology development, and the accuracy of data measurement directly affects the success or failure of the experiment. However, when viscous materials adhere to the thermocouple tube, the thermocouple cannot accurately and promptly detect the true temperature within the reaction system, and the linked heater cannot maintain the system temperature at the target temperature. Temperature is the most flexible and direct means of regulating chemical reactions. Inaccurate temperature readings can distort reaction results and mislead research direction. To address the issue of viscous materials adhering to thermocouple tubes, some researchers have used heating wires inside the tubes to appropriately increase the temperature and remove the adhering material. However, this method relies on the thermocouple's wall temperature after heating, which is higher than the temperature of the material inside the system. This causes a delay in the operation of the heater, which is interlocked with the thermocouple. Furthermore, it's difficult to determine how long it will take to completely remove the adhering material, and even after removal, the thermocouple may re-adhere after a period of time, with the time interval and degree of adhesion being difficult to ascertain. This can lead to either excessively frequent heater starts or only starting when adhesion is severe, both causing periodic fluctuations in system temperature and making accurate and stable temperature control impossible. The problem of viscous materials adhering to thermocouple tubes in experimental setups has long plagued researchers in related fields. Therefore, there is an urgent need to develop a thermocouple that can prevent viscous materials from adhering to experimental setups to address this pressing issue. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a thermocouple tube suitable for experimental devices to prevent the adhesion of sticky materials.

[0004] To solve the above-mentioned technical problems, this utility model provides a thermocouple protection tube suitable for materials that are prone to sticking to the wall. It includes a reaction system for placing the thermocouple tube and a film-forming liquid injection system for injecting film-forming liquid into the thermocouple tube. The main body of the thermocouple tube is a microporous sintered metal structure. After the film-forming liquid is injected into the main body of the thermocouple tube, an anti-sticking film is formed on the outer wall of the thermocouple tube.

[0005] Preferably, the thermocouple tube includes part A located outside the reaction system and part B located inside the reaction system; part A is a stainless steel tube and part B is a microporous sintered metal structure (with uniformly distributed micropores and a smooth surface).

[0006] More preferably, part A is a ferrule or flange. The selection of the inner diameter and main body length of the thermocouple tube should ensure that the internal material has sufficient residence time, so that the temperature of the liquid inside the tube is consistent with that of the reaction system, and that the thermocouple always detects the true temperature inside the system.

[0007] Preferably, the film-forming liquid injection system includes a storage tank connected to a thermocouple tube via a pipeline. The injected film-forming liquid is a reactant in the system or a substance that does not interfere with the reaction. The injection flow rate is designed to form a liquid film on the outer wall of the thermocouple tube that prevents the adhesion of viscous materials in the system.

[0008] More preferably, the pipeline is equipped with a one-way valve. The one-way valve prevents the reaction system material from flowing back into the pumping system through the microporous thermocouple tube.

[0009] Preferably, the pipeline is equipped with a feed pump.

[0010] More preferably, the feed pump is a micro-metering pump. The feed pump is selected as a micro-metering pump, or the pump and a low-flow meter form a flow control loop to ensure that the injected liquid forms a liquid film on the outer wall of the thermocouple tube that prevents the adhesion of viscous materials in the system.

[0011] Preferably, a pressure gauge is installed on the pipeline. The pressure gauge displays a pressure that is substantially the same as the pressure of the reaction system.

[0012] The thermocouple protection tube provided by this utility model can prevent the adhesion of sticky materials, prevent the periodic fluctuation of system temperature, and enable the reaction temperature to be controlled more stably. Attached Figure Description

[0013] Figure 1 A schematic diagram of the thermocouple protection tube for materials that easily stick to the wall provided by this utility model;

[0014] Figure 2 for Figure 1 A magnified view of part I. Detailed Implementation

[0015] To make this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0016] Example

[0017] like Figure 1 , 2 As shown, this utility model provides a thermocouple protection tube suitable for materials that easily stick to the wall. It includes a reaction system 8 for placing the thermocouple tube 1 and a film-forming liquid injection system for injecting film-forming liquid into the thermocouple tube 1. The thermocouple 7 is placed inside the thermocouple tube 1.

[0018] The thermocouple tube 1 includes part A located outside the reaction system 8 and part B located inside the reaction system 8. Part A is a stainless steel tube, and part B is a microporous sintered metal structure. After the film-forming liquid is injected from the top inlet of the thermocouple tube 1, it forms an anti-sticking film C on the outer wall of part B. The thickness δ of the anti-sticking film is much smaller than the inner radius R of the thermocouple tube 1. Part A is fixed inside the reaction system 8 by a ferrule or flange.

[0019] The film-forming liquid injection system includes a storage tank 2, the bottom of which is connected in sequence to a feed pump 3, a pressure gauge 4, a check valve 5, and a thermocouple 1 via a pipeline 6. The feed pump 3 is preferably a micro-metering pump.

[0020] Before use, the film formation on the outer wall of the thermocouple tube is tested using the liquid material used in the reaction system. A micro-metering pump is used to inject the liquid reactant or solvent into the thermocouple tube at a pre-calculated flow rate, and the film formation on the outer wall is observed. If the formed liquid film is uniform in thickness, the flow rate is appropriately reduced, i.e., the film thickness is decreased, and observation continues. The minimum flow rate at which a uniform liquid film thickness is formed is ultimately used as the set flow rate for the thermocouple tube during use. The discharge pressure of the micro-metering pump should be determined by the sum of the pump outlet pressure during the film formation test and the maximum test pressure.

[0021] The selection of the thermocouple tube's inner diameter must consider the length exposed to the system's temperature environment within the tube. The liquid volume within the tube must be calculated to ensure a sufficient residence time for the liquid, guaranteeing that the materials in the system can heat the liquid to the system temperature, thus ensuring the accuracy of the thermocouple's temperature readings. The thermocouple tube requires uniform micropore distribution and a smooth outer surface. Because the injected liquid flow rate is very low, it will not interfere with the composition of the reactants, nor should the flow rate of the injected material be deducted from the feed rate. As the continuously injected liquid seeps out of the thermocouple tube, a liquid film forms on the outer wall, preventing the adhesion of viscous materials. Even if the liquid film on the outer wall is carried away by the material, a new liquid film will continuously form, preventing viscous materials from adhering to the outer wall of the thermocouple tube.

Claims

1. A thermocouple protection tube suitable for materials that easily stick to the wall, characterized in that, It includes a reaction system (8) for placing the thermocouple tube (1) and a film-forming liquid injection system for injecting film-forming liquid into the thermocouple tube (1); the main body of the thermocouple tube (1) is a microporous sintered metal structure, and after the film-forming liquid is injected into the main body of the thermocouple tube (1), an anti-sticking film is formed on the outer wall of the thermocouple tube (1).

2. The thermocouple protection tube as described in claim 1, characterized in that, The thermocouple tube (1) includes part A located outside the reaction system (8) and part B located inside the reaction system (8); part A is a stainless steel tube and part B is a microporous sintered metal structure.

3. The thermocouple protection tube as described in claim 2, suitable for materials that easily stick to the wall, characterized in that, Part A uses a ferrule or flange.

4. The thermocouple protection tube as described in claim 1, characterized in that, The film-forming liquid injection system includes a storage tank (2), which is connected to a thermocouple pipe (1) via a pipeline (6).

5. The thermocouple protection tube as described in claim 4, characterized in that, A one-way valve (5) is provided on the pipeline (6).

6. The thermocouple protection tube as described in claim 4 or 5, suitable for materials that easily stick to the wall, characterized in that, The pipeline (6) is equipped with a feed pump (3).

7. The thermocouple protection tube as described in claim 6, characterized in that, The feed pump (3) is a micro-metering pump.

8. The thermocouple protection tube as described in claim 4 or 5, suitable for materials that easily stick to the wall, characterized in that, A pressure gauge (4) is installed on the pipeline (6).

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