Modularized heating unit of test cabin resistance heating furnace

Abstract

The invention discloses modular heating units of a test cabin resistance heating furnace, which are uniformly distributed on the inner wall of a furnace body along the circumferential direction and the axial direction. Each unit comprises a pair of hangers, a core shaft which is transversely arranged and vertically distributed, a ceramic disc and a ceramic shaft sleeve which are sleeved on each core shaft in a non-rotating matching manner and are uniformly distributed, a plurality of spiral resistance wires, and a temperature measuring element which is used for monitoring the temperature of the unit so as to independently control the temperature of the unit; clamping seats with downward openings are vertically distributed on one sides of the hangers, supporting seats with upward openings are vertically distributed on the other sides of the hangers, the clamping seats are used for being downwards inserted and installed on connecting components on the inner wall of the furnace body, the two ends of the mandrel are supported on the supporting seats on the same layer of the hangers on the two sides, the adjacent ceramic discs are separated through ceramic shaft sleeves, and through holes are evenly distributed in the ceramic discs around the axis. The through holes of the ceramic discs on the same mandrel are aligned, the resistance wires are distributed according to the rows of through holes, and each resistance wire penetrates through the corresponding row of through holes. Uniform heating in the furnace body can be achieved, assembly and disassembly are convenient, and the heating efficiency is high.

Description

Technical Field

[0001] The invention relates to geotechnical engineering tests, and in particular to a modular heating unit of a resistance heating furnace in a test chamber. Background Art

[0002] As major infrastructure construction and resource and energy development continue to advance into deep earth and active geological tectonic areas, engineering construction is more difficult than ever before, facing complex environments such as high ground stress, high osmotic pressure, high geothermal temperature and strong engineering disturbances. This makes the implementation of deep geotechnical engineering extremely difficult, so experimental research is needed.

[0003] In order to simulate the deep multi-field coupling environment and engineering disturbance conditions on the ground, and accurately observe and control the evolution of the internal discontinuous structure and external nonlinear behavior of the rock mass, many geotechnical engineering disturbance simulation facilities have been developed for experimental research. The simulation facilities need to apply the required pressure load to the test cabin and accurately control it, and also need to apply the required temperature load to the test cabin and accurately control it. Since the test cabin has the characteristics of large single-piece volume, heavy weight, and thick walls, heating only the inside is not conducive to rapid heating and subsequent insulation. Therefore, some simulation facilities will design a resistance heating furnace, use the furnace body to cover the test cabin and use resistance to heat the outer wall of the test cabin.

[0004] However, the current test chamber resistance heating furnace has the following problems: 1) The test chamber itself is very large, and the resistance heating furnace that wraps the test chamber is even larger. Therefore, the heating surface on the inner wall of the furnace is very large, but the distance from the outer wall of the test chamber is very small. The current resistors are installed in a distributed manner and controlled uniformly, which can easily cause uneven heating. Moreover, the furnace body is relatively high, which will cause hot air to float up, further causing uneven heating; 2) Currently, resistors are installed on insulating porcelain tubes, and the insulating porcelain tubes are installed one by one on the inner wall of the furnace body, making it inconvenient to load and unload all resistors; 3) Currently, resistors are installed on insulating porcelain tubes in a winding manner. The insulating porcelain will shield the rear area of ​​the resistor, reducing the heating efficiency. In addition, only one resistor is installed on the same insulating porcelain tube, and the number of resistors installed per unit space is small, affecting the overall heating efficiency. Summary of the invention

[0005] The object of the present invention is to provide a modular heating unit for a test chamber resistance heating furnace, which can achieve uniform heating inside the furnace body, convenient loading and unloading, and high heating efficiency.

[0006] The technical solution adopted by the present invention is: A modular heating unit of a test chamber resistance heating furnace is evenly distributed on the inner wall of the furnace body along the circumferential and axial directions, and each unit is independent of each other; each unit includes a pair of hangers, a horizontally and vertically distributed core shaft, a ceramic disc and a ceramic sleeve that are non-rotatably fitted on each core shaft and evenly distributed, a plurality of spiral resistance wires, and a temperature measuring element for monitoring the temperature of the unit for independent temperature control of the unit; a downwardly open holder is vertically distributed on one side of the hanger, and an upwardly open bracket is vertically distributed on the other side; the holder is used to be inserted downwardly on a connecting member installed on the inner wall of the furnace body, the two ends of the core shaft are supported on the same-layer brackets of the hangers on both sides, adjacent ceramic discs are separated and axially limited by ceramic sleeves, through holes are evenly distributed on the ceramic discs around the axis, the through holes of each ceramic disc on the same core shaft are aligned, the resistance wires are distributed according to each row of through holes, and each resistance wire passes through a corresponding row of through holes.

[0007] Preferably, the core shaft is a square shaft, and the centers of the ceramic disc and the ceramic sleeve are both provided with square holes for clearance fit with the square shaft.

[0008] Preferably, threaded holes are provided at both end faces of the mandrel, and screws cooperate with the threaded holes to mount the anti-slipping sheet on the end faces of the mandrel. The anti-slipping sheet is used to prevent the ceramic disc and the ceramic sleeve from slipping off the mandrel.

[0009] Preferably, limiting holes are provided near both ends of the core shaft, and limiting members are installed on the limiting holes. The limiting members are used to axially limit the ceramic discs near the ends.

[0010] Preferably, the resistance wire passes through the through hole on the middle ceramic disc at the same time, leaving the through holes on the ceramic discs at both ends unpassed.

[0011] Preferably, the hanger and the mandrel are made of stainless steel.

[0012] Preferably, the resistance wire is made of high-nickel Cr20Ni80 material.

[0013] Preferably, the ceramic disc and the ceramic sleeve are made of high temperature resistant sintered corundum material.

[0014] Preferably, each unit is equipped with two temperature measuring elements, one of which is used for temperature control and recording, and the other is used for over-temperature alarm.

[0015] Preferably, during installation, first use the socket to insert the hanger downward onto the connecting member installed on the inner wall of the furnace body, alternately put the ceramic discs and ceramic sleeves on the core shaft and ensure that the through holes of the ceramic discs on the same core shaft are aligned, then pass the resistance wire through the corresponding row of through holes, and then place the assembled core shaft downward on the same layer of the hangers on both sides; when the resistance wire needs to be replaced, wait until the temperature drops, first take out the core shaft upward, then pull out the resistance wire to be replaced, then pass the new resistance wire through the corresponding row of through holes, and then place the assembled core shaft downward on the same layer of the hangers on both sides.

[0016] The beneficial effects of the present invention are: The unit adopts a modular structure, is evenly distributed on the inner wall of the furnace body in the circumferential and axial directions and can independently control the temperature. Therefore, the large size and high height of the furnace body are fully taken into consideration, and uniform heating of the inside of the furnace body can be achieved. In this unit, the resistance wire can be drawn out or placed in a row of through holes, the core shaft can be directly placed downward on the hanger or taken out upward, and the hanger can be directly inserted downward on the connecting member of the inner wall of the furnace body and taken out upward, which is convenient for loading and unloading, maintenance and replacement. In this unit, the resistance wire is spiral-shaped and has high heating efficiency. The key is that the resistance wire only passes through a row of through holes and is not installed on an insulating porcelain tube. Therefore, it is basically an air-suspended installation without shielding, which ensures the heating effect. In addition, multiple resistance wires can be installed on the same core shaft, and the amount of resistance installed per unit space is large, which further improves the heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a dimensional drawing of the front view of the modular heating unit of the resistance heating furnace in the test chamber in an embodiment of the present invention.

[0018] Figure 2 It is a dimensional drawing of the modular heating unit of the resistance heating furnace in the test chamber in an embodiment of the present invention from a top view.

[0019] Figure 3 It is a dimensional drawing of the modular heating unit of the resistance heating furnace in the test chamber in an embodiment of the present invention from a side view.

[0020] Figure 4 1 is a dimensional diagram of the bracket in the embodiment of the present invention when viewed from above.

[0021] Figure 5 It is a dimensional diagram of the mandrel, ceramic disc, ceramic sleeve and resistance wire after installation in the embodiment of the present invention.

[0022] Figure 6 2 is a dimensional diagram of the mandrel in an embodiment of the present invention.

[0023] Figure 7 2 is a dimensional diagram of the resistance wire in an embodiment of the present invention.

[0024] Figure 8 2 is a dimensional diagram of a ceramic disc in an embodiment of the present invention.

[0025] Fig. 9 2 is a dimensional diagram of a ceramic bushing in an embodiment of the present invention.

[0026] In the figure: 1-hanging bracket; 11-holder; 12-supporting seat; 2-screw; 3-anti-dropping sheet; 4-core shaft; 5-ceramic disc; 6-resistance wire; 7-ceramic bushing; a-limiting hole; b-through hole; c-square hole. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0030] The present application discloses a modular heating unit of a test chamber resistance heating furnace, wherein the units are evenly distributed in the circumferential direction and the axial direction on the inner wall of the furnace body, and each unit is independent of each other; Figures 1 to 5 As shown, the unit includes a hanger 1, a core shaft 4, a ceramic disc 5, a ceramic sleeve 7, a resistance wire 6 and a temperature measuring element; wherein: Each unit adopts a pair of racks 1, one side of the rack 1 is vertically distributed with a downward opening holder 11, and the other side is vertically distributed with an upward opening bracket 12, the holder 11 is used to be inserted downwardly on the connecting member installed on the inner wall of the furnace body, Figures 1 to 4 ; The mandrel 4 is horizontally arranged and vertically distributed, and the two ends of the mandrel 4 are supported on the same-layer brackets 12 of the two side brackets 1. Figures 1 to 3 , Figure 5 ; The ceramic discs 5 and the ceramic sleeves 7 are non-rotatably fitted on the core shafts 4 and are evenly distributed. The adjacent ceramic discs 5 are separated and axially limited by the ceramic sleeves 7. The ceramic discs 5 are evenly distributed with through holes b around the axis. The through holes b of the ceramic discs 5 on the same core shaft 4 are aligned. Figure 1 , Figure 2 , Figure 5 , Figure 8 and Fig. 9 ; The resistance wire 6 is spiral-shaped, and the resistance wire 6 is distributed according to each row of through holes b and each resistance wire 6 passes through a corresponding row of through holes b. Figure 1 , Figure 2 , Figure 5 and Figure 7 ; The temperature measuring element is used to monitor the temperature of the unit so as to provide independent temperature control for the unit. The temperature measuring element is directly installed on the furnace body and is not shown in the figure.

[0031] According to the above scheme: The units adopt a modular structure, are evenly distributed on the inner wall of the furnace body in the circumferential and axial directions, and can independently control the temperature. Therefore, the large size and height of the furnace body are fully taken into consideration, and uniform heating inside the furnace body can be achieved; In this unit, the resistance wire 6 can be drawn out or put into a row of through holes b, the mandrel 4 can be directly placed downward on the hanger 1 or taken out upward, and the hanger 1 can be directly inserted downward on the connecting member of the inner wall of the furnace body and taken out upward, which is convenient for loading and unloading, maintenance and replacement; In this unit, the resistance wire 6 is spiral-shaped and has high heating efficiency. The key is that the resistance wire 6 only passes through a row of through holes b and is not installed on an insulating porcelain tube. Therefore, it is basically installed in an air-suspended manner without shielding, thereby ensuring the heating effect. In addition, multiple resistance wires 6 can be installed on the same core shaft 4, and the amount of resistance installed per unit space is large, further improving the heating efficiency.

[0032] In this embodiment, preferably: Figure 6 , Figure 8 and Fig. 9 As shown, the core shaft 4 adopts a square shaft, and the centers of the ceramic disc 5 and the ceramic sleeve 7 are provided with square holes c for clearance fit with the square shaft. The fit between the square shaft and the square hole c can avoid damage to the resistance wire 6 caused by the rotation of the ceramic disc 5 and the ceramic sleeve 7, and the clearance fit facilitates the installation of the ceramic disc 5 and the ceramic sleeve 7.

[0033] In this embodiment, preferably: Figures 1 to 3 , Figure 5 and Figure 6 As shown, threaded holes are provided at both end faces of the core shaft 4, and screws 2 cooperate with the threaded holes to install the anti-slip sheet 3 on the end faces of the core shaft 4. The anti-slip sheet 3 is used to prevent the ceramic disc 5 and the ceramic sleeve 7 from falling off the core shaft 4. During the loading and unloading process, the core shaft 4 cannot be kept level throughout the entire process. Therefore, the ceramic disc 5 and the ceramic sleeve 7 may fall off the core shaft 4 along the inclined direction. The anti-slip sheet 3 can prevent the two from falling off the core shaft 4.

[0034] In this embodiment, preferably: Figure 2 , Figure 5 and Figure 6 As shown, limit holes a are provided near both ends of the core shaft 4, and limit members are installed on the limit holes a. The limit members are used to axially limit the ceramic disc 5 near the end to prevent the ceramic disc 5 from moving laterally and being damaged during test vibration.

[0035] In this embodiment, preferably: Figure 1 , Figure 2 and Figure 5 As shown, the resistance wire 6 passes through the through hole b on the middle ceramic disc 5 at the same time, leaving the through holes b on the ceramic discs 5 at both ends unpassed, so as to prevent the resistance wire 6 from being too close to cause the hanger 1 to deform at high temperature. The ceramic discs 5 at both ends can protect the hanger 1 from high temperature radiation.

[0036] In this embodiment, preferably: the bracket 1 and the core shaft 4 are made of stainless steel, which is heat-resistant and corrosion-resistant; the resistance wire 6 is made of high-nickel Cr20Ni80 material, which has a long service life and is easy to process. The resistance wire 6 is easily damaged after long-term use, so a better material is selected; the ceramic disc 5 and the ceramic sleeve 7 are made of high-temperature resistant sintered corundum material, which is heat-resistant, not easy to damage, and has a long service life.

[0037] In this embodiment, preferably: each unit is equipped with two temperature measuring elements, one of which is used for temperature control and recording, and the other is used for over-temperature alarm to improve safety redundancy.

[0038] In this embodiment, preferably: the furnace body adopts a split structure of two semicircular furnace bodies, the two semicircular furnace bodies can be enclosed and separated, the entire furnace body is evenly divided into 10 zones along the circumferential direction and 3 layers along the axial direction, forming a total of 30 heating areas, and the two semicircular furnace bodies each have 15 heating areas, and each heating area is arranged with a unit. Because the furnace temperature is relatively low (the working temperature is about 300°C) and the heating time is relatively long, the total heating power is determined to be 450kw, that is, the heating power of each heating area is 15kw. Since the heating power of a single heating area is relatively small, single-phase heating of each heating area can be conventionally adopted. However, considering that there are too many heating areas, it is easy to cause unbalanced load to the use area, so three-phase heating of each heating area is adopted.

[0039] The specific dimensions of each component in the unit are designed according to actual needs. In the present embodiment, the height of the bracket 1 is 750 mm, the spacing of the holder 11 is 300 mm, the spacing of the bracket 12 is 300 mm, and the spacing of the core shaft 4 is 300 mm; the total length of the core shaft 4 is 880 mm, the cross section of the core shaft 4 is 20 mm*20 mm, and the area occupied by the ceramic disc 5 and the ceramic sleeve 7 on the core shaft 4 is 792 mm; the total length of the resistance wire 6 is 710 mm, and the outer diameter of the resistance wire 6 is 22.5 mm; the outer diameter of the ceramic disc 5 is 145 mm, the thickness of the ceramic disc 5 is 12 mm, the size of the square hole c of the ceramic disc 5 is 21 mm*21 mm, the inner diameter of the through hole b of the ceramic disc 5 is 27 mm, and there are 6 through holes b evenly distributed on the ceramic disc 5; the outer diameter of the ceramic sleeve 7 is 46 mm, the thickness of the ceramic sleeve 7 is 40 mm, and the size of the square hole c of the ceramic sleeve 7 is 21 mm*21 mm.

[0040] During installation, first use the socket 11 to insert the hanger 1 downward and install it on the connecting component on the inner wall of the furnace body, alternately put the ceramic disc 5 and the ceramic sleeve 7 on the core shaft 4 and ensure that the through holes b of each ceramic disc 5 on the same core shaft 4 are aligned, then pass the resistance wire 6 through the corresponding row of through holes b, and then place the assembled core shaft 4 downward on the same-layer support 12 of the hangers 1 on both sides; when the resistance wire 6 needs to be replaced, wait until the temperature drops, first take out the core shaft 4 upward, then pull out the resistance wire 6 that needs to be replaced, then pass the new resistance wire 6 through the corresponding row of through holes b, and then place the assembled core shaft 4 downward on the same-layer support 12 of the hangers 1 on both sides.

[0041] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A modular heating unit for a test chamber resistance heating furnace, characterized in that: They are evenly distributed on the inner wall of the furnace body along the circumferential and axial directions, and each unit is independent of each other; each unit includes a pair of hangers, a horizontally and vertically distributed core shaft, a ceramic disc and a ceramic sleeve that are non-rotatably fitted on each core shaft and evenly distributed, a number of spiral resistance wires, and a temperature measuring element for monitoring the temperature of the unit so as to provide independent temperature control for the unit, a downward-opening holder is vertically distributed on one side of the hanger, and an upward-opening bracket is vertically distributed on the other side, the holder is used to be inserted downwardly on a connecting component installed on the inner wall of the furnace body, both ends of the core shaft are supported on the same-layer brackets of the hangers on both sides, adjacent ceramic discs are separated and axially limited by ceramic sleeves, through holes are evenly distributed on the ceramic disc around the axis, the through holes of each ceramic disc on the same core shaft are aligned, the resistance wires are distributed according to each row of through holes and each resistance wire passes through a corresponding row of through holes.

2. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: The core shaft adopts a square shaft, and the centers of the ceramic disc and the ceramic sleeve are both provided with square holes for clearance matching with the square shaft.

3. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: The two end faces of the mandrel are provided with threaded holes, and the screws cooperate with the threaded holes to install the anti-dropping piece on the end face of the mandrel. The anti-dropping piece is used to prevent the ceramic disc and the ceramic sleeve from falling off from the mandrel.

4. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: Limiting holes are arranged near the two ends of the core shaft, and limiting members are installed on the limiting holes. The limiting members are used to axially limit the ceramic disc near the end.

5. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: The resistance wire passes through the through hole on the middle ceramic disc at the same time, leaving the through holes on the ceramic discs at both ends unpassed.

6. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: The hanger and mandrel are made of stainless steel.

7. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: The resistance wire is made of high nickel Cr20Ni80 material.

8. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: The ceramic disc and the ceramic sleeve are made of high temperature resistant sintered corundum.

9. The modular heating unit of the test chamber resistance heating furnace according to claim 1, characterized in that: Each unit is equipped with two temperature measuring elements, one of which is used for temperature control and recording, and the other is used for over-temperature alarm.

10. The modular heating unit of the test chamber resistance heating furnace according to any one of claims 1 to 9, characterized in that: During installation, first use the clamping seat to insert the hanger downward and install it on the connecting component on the inner wall of the furnace body, alternately put the ceramic discs and ceramic sleeves on the core shaft and ensure that the through holes of the ceramic discs on the same core shaft are aligned, then pass the resistance wire through the corresponding row of through holes, and then place the assembled core shaft downward on the same layer of the hangers on both sides; when the resistance wire needs to be replaced, wait until the temperature drops, first take out the core shaft upward, then pull out the resistance wire to be replaced, then pass the new resistance wire through the corresponding row of through holes, and then place the assembled core shaft downward on the same layer of the hangers on both sides.

Images