A heating furnace

Abstract

The present invention discloses a heating furnace, belonging to the field of heating equipment. The furnace body comprises an inner tube, a first gas interlayer, an outer tube, a second gas interlayer, a heat storage layer, and a cooling water interlayer, arranged in order from the inside out. The inner tube's inner cavity serves as a heating reaction zone, a heating element is wrapped around the outer wall of the inner tube, and the inner wall of the outer tube is coated with a thermal insulation coating. The thermal insulation coating can reflect the heat radiation of the heating element back to the center of the inner tube, achieving the purpose of heat preservation. The thermal insulation effect of the thermal insulation coating can reduce the load and thickness of the thermal storage layer, thereby reducing the overall size of the furnace body, reducing the heat capacity during cooling, and accelerating the cooling rate. The two gas interlayers are provided, and the gas removes the heat of the interlayers, thereby achieving rapid cooling. The cooling water interlayer is provided, and the water removes the heat of the interlayers, while simultaneously reducing the temperature of the outer wall of the furnace body, preventing burns. The heating furnace has a simple structure, a small volume, and is easy to manufacture.

Description

Technical Field

[0001] The present invention relates to the technical field of heating equipment, in particular to a heating furnace. Background Art

[0002] Physical and chemical processes in process industries require constant temperature conditions. Furnaces are often the equipment that provides heat for these processes. Furnace structure determines its performance. For example, different exterior wall materials, resistance wire diameter and material, and insulation material and thickness often have a comprehensive impact on the furnace's heating rate, maximum heating temperature, insulation performance, temperature control accuracy, and stability.

[0003] Today's heating furnaces are already capable of rapidly heating up and reaching maximum temperatures that meet the demands of scientific experiments and industry. However, they often struggle to achieve both precise and stable temperature control and rapid cooling. This results in unstable temperature conditions during fluidized bed reactions, leading to deviations between the actual and ideal reactions. Furthermore, most commercially available furnaces exhibit slow cooling rates, significantly reducing operator efficiency.

[0004] Currently, there are some heating furnaces that have been improved to address the above-mentioned issues, but there are still problems such as insignificant cooling effect, high processing difficulty, and high price. Summary of the Invention

[0005] The object of the present invention is to provide a heating furnace with fast heating and cooling rates, simple structure, small size and low processing difficulty.

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

[0007] A heating furnace, comprising:

[0008] A furnace body having a receiving cavity;

[0009] An inner tube is disposed in the accommodating cavity, wherein the inner cavity of the inner tube serves as a heating reaction zone;

[0010] a heating element, wound around the outer wall of the inner tube;

[0011] an outer tube, disposed in the accommodating cavity and sleeved on the outer circumference of the inner tube at intervals, with a first gas interlayer between the outer tube and the heating element;

[0012] a heat-insulating coating applied to the inner wall of the outer tube, the heat-insulating coating being used to reflect the heat generated by the heating element;

[0013] A heat storage layer is arranged in the accommodating cavity and is spaced apart and sleeved on the outer circumference of the outer tube. A second gas interlayer is provided between the heat storage layer and the outer tube, and a cooling water interlayer is provided between the heat storage layer and the inner wall of the furnace body.

[0014] As a preferred technical solution of the above-mentioned heating furnace, the furnace body includes:

[0015] a housing, wherein the housing is annular;

[0016] a furnace cover, sealed and connected to the top of the shell;

[0017] The furnace bottom is sealed and connected to the bottom of the shell.

[0018] As a preferred technical solution of the above heating furnace, the heating furnace further includes:

[0019] A thermocouple, one end of which passes through the furnace cover and is inserted into the heating reaction zone, and the other end of which extends out of the furnace cover and is electrically connected to a control device.

[0020] As a preferred technical solution of the above heating furnace, the inner surface of the furnace cover is provided with a first fixing groove, a second fixing groove and a third fixing groove in sequence from the center to the periphery, which are used to fix the top end of the inner tube, the top end of the outer tube and the top end of the heat storage layer respectively;

[0021] The inner surface of the furnace bottom is provided with a fourth fixing groove arranged opposite to the first fixing groove, a fifth fixing groove arranged opposite to the second fixing groove, and a sixth fixing groove arranged opposite to the third fixing groove in sequence from the center to the outer periphery. The fourth fixing groove, the fifth fixing groove, and the sixth fixing groove are used to fix the bottom end of the inner tube, the bottom end of the outer tube, and the bottom end of the heat storage layer, respectively.

[0022] As the preferred technical solution of the above heating furnace,

[0023] A first gas inlet is provided on the furnace bottom corresponding to the first gas interlayer, and a first gas outlet is provided on the furnace cover corresponding to the first gas interlayer;

[0024] A second gas inlet is provided on the furnace bottom corresponding to the second gas interlayer, and a second gas outlet is provided on the furnace cover corresponding to the second gas interlayer;

[0025] A water inlet is provided on the furnace bottom corresponding to the cooling water interlayer, and a water outlet is provided on the furnace cover corresponding to the cooling water interlayer.

[0026] As a preferred technical solution of the above heating furnace, the heating furnace further includes:

[0027] A partition is arranged between the heat storage layer and the cooling water interlayer.

[0028] As a preferred technical solution of the above-mentioned heating furnace, the inner tube is made of corundum.

[0029] As a preferred technical solution of the above-mentioned heating furnace, the heating element is a platinum wire or a platinum-rhodium wire.

[0030] As a preferred technical solution of the above-mentioned heating furnace, the thermal insulation coating is made of one of platinum and rhodium.

[0031] As a preferred technical solution of the above-mentioned heating furnace, the heat storage layer is made of one of aluminum silicate refractory fiber cotton, glass fiber cotton, and ceramic fiber cotton.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The heating furnace proposed by the present invention has an inner tube, a first gas interlayer, an outer tube, a second gas interlayer, a heat storage layer, and a cooling water interlayer arranged in order from the inside to the outside within the accommodating cavity of the furnace body. The inner tube's inner cavity serves as a heating reaction zone, the outer wall of the inner tube is wrapped with a heating element, and the inner wall of the outer tube is coated with a thermal insulation coating. The thermal insulation coating can reflect the heat radiation of the heating element back to the center of the inner tube, preventing heat loss and achieving the purpose of heat preservation. At the same time, the thermal insulation effect of the thermal insulation coating can effectively reduce the load on the heat storage layer, reduce the thickness of the heat storage layer, and minimize the heat capacity of the heat storage layer, thereby reducing the overall size of the furnace body, reducing the heat capacity during cooling, and accelerating the cooling rate. By providing two gas interlayers, the heat of the interlayers is removed by gas, thereby achieving rapid cooling. By providing a cooling water interlayer, the heat of the interlayer is removed by water, thereby removing excess heat and reducing the temperature of the outer wall of the furnace body, providing a safety function and preventing burns. The heating furnace has a simple structure, is easy to disassemble and replace components, has a compact structure and a small size, and is easy to process. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of a heating furnace provided in a specific embodiment of the present invention.

[0035] In the picture:

[0036] 1. Inner tube; 2. Heating element; 3. Insulation coating; 4. Outer tube; 5. Heat storage layer; 6. First gas interlayer; 7. Second gas interlayer; 8. Cooling water interlayer; 9. Outer shell; 10. Furnace cover; 101. Through hole; 11. Furnace bottom; 12. Thermocouple; 13. First gas inlet; 14. First gas outlet; 15. Second gas inlet; 16. Second gas outlet; 17. Water inlet; 18. Water outlet; 19. Control device. DETAILED DESCRIPTION

[0037] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the drawings only show portions relevant to the present invention, not all of them.

[0038] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0039] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., referring to positions or locations, are based on the positions or locations shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0041] This embodiment discloses a heating furnace, such as Figure 1As shown, the heating furnace includes a furnace body, which has a receiving cavity. Specifically, the furnace body includes a furnace cover 10, a furnace bottom 11 and an outer shell 9. The outer shell 9 is annular. The furnace cover 10 and the furnace bottom 11 are sealed to the top and bottom of the outer shell 9 respectively, and the three together form the above-mentioned receiving cavity. Optionally, the annular outer shell 9 is connected to the furnace cover 10 and the furnace bottom 11 respectively through matching threaded holes and screws, and a sealing structure is provided between the outer shell 9 and the furnace cover 10 and the furnace bottom 11. Further optionally, the side of the furnace bottom 11 and the side of the furnace cover 10 are respectively provided with furnace bottom threaded holes and furnace cover threaded holes, which are fixed to the matching stainless steel bracket by matching screws, thereby achieving the fixation of the heating furnace and the stainless steel bracket.

[0042] The accommodating cavity is provided with an inner tube 1, a first gas interlayer 6, an outer tube 4, a second gas interlayer 7, a heat storage layer 5 and a cooling water interlayer 8 in sequence from the inside to the outside. The inner cavity of the inner tube 1 is a heating reaction zone, the outer wall of the inner tube 1 is wrapped with a heating element 2, the outer tube 4 is arranged at intervals on the outer periphery of the inner tube 1, the inner wall of the outer tube 4 is coated with a thermal insulation coating 3, and the heat storage layer 5 is arranged at intervals on the outer periphery of the outer tube 4.

[0043] Under the above structure, the thermal insulation coating 3 can reflect the heat radiation of the heating element 2 back into the inner tube 1, thereby preventing heat loss and achieving the purpose of heat preservation; at the same time, the thermal insulation effect of the thermal insulation coating 3 can effectively reduce the load of the heat storage layer 5, reduce the thickness of the heat storage layer 5, and minimize the heat capacity of the heat storage layer 5, which also makes the overall size of the furnace body smaller, and the heat capacity is small during cooling, and the cooling speed is faster; by setting two gas interlayers, the heat of the interlayer is taken away by gas, which can achieve rapid cooling; by setting a cooling water interlayer 8, the heat of the interlayer is taken away by water, which can take away excess heat and reduce the temperature of the outer wall of the furnace body at the same time, which has a safety effect and can prevent burns. The heating furnace adopts a three-coupled insulation method, namely, a thermal insulation method of coupled reflective insulation, gas insulation and solid thermal storage insulation. Under the same heat, the heating rate is high, and the heating furnace has a simple structure, which is convenient for disassembly and replacement of components. It has a compact structure and a small size, and is easy to process.

[0044] The heating furnace further includes a thermocouple 12. A through-hole 101 is provided in the furnace cover 10. One end of the thermocouple 12 passes through the through-hole 101 and is inserted into the heating reaction zone. The other end extends out of the furnace cover 10 and is electrically connected to the control device 19. This measures and monitors the temperature of the heating reaction zone, thereby controlling heating and cooling. Preferably, the outer wall of the thermocouple 12 is wrapped with a protective sleeve (not shown).

[0045] In order to fix the inner tube 1, the outer tube 4 and the heat storage layer 5 in the accommodating cavity, the inner surface of the furnace cover 10 is provided with a first fixing groove, a second fixing groove and a third fixing groove in sequence from the center to the periphery, which are used to fix the top end of the inner tube 1, the top end of the outer tube 4 and the top end of the heat storage layer 5 respectively; accordingly, the inner surface of the furnace bottom 11 is provided with a fourth fixing groove arranged opposite to the first fixing groove, a fifth fixing groove arranged opposite to the second fixing groove and a sixth fixing groove arranged opposite to the third fixing groove in sequence from the center to the periphery, and the fourth fixing groove, the fifth fixing groove and the sixth fixing groove are used to fix the bottom end of the inner tube 1, the bottom end of the outer tube 4 and the bottom end of the heat storage layer 5 respectively.

[0046] Furthermore, a first gas inlet 13 is provided on the furnace bottom 11 corresponding to the first gas interlayer 6, and a first gas outlet 14 is provided on the furnace cover 10 corresponding to the first gas interlayer 6; a second gas inlet 15 is provided on the furnace bottom 11 corresponding to the second gas interlayer 7, and a second gas outlet 16 is provided on the furnace cover 10 corresponding to the second gas interlayer 7; a water inlet 17 is provided on the furnace bottom 11 corresponding to the cooling water interlayer 8, and a water outlet 18 is provided on the furnace cover 10 corresponding to the cooling water interlayer 8. More preferably, the first gas inlet 13, the second gas inlet 15, and the water inlet 17 are fixed to the furnace bottom 11 by threaded connections, and the first gas outlet 14, the second gas outlet 16, and the water outlet 18 are fixed to the furnace cover 10 by threaded connections.

[0047] In the first gas interlayer 6, gas enters the first gas interlayer 6 from the first gas inlet 13 at a certain flow rate and leaves from the first gas outlet 14, thereby taking away the heat in the first gas interlayer 6, that is, taking away the heat of the inner tube 1, so that the outer tube 4 is quickly cooled.

[0048] In the second gas interlayer 7, gas enters the second gas interlayer 7 from the second gas inlet 15 at a certain flow rate and leaves from the second gas outlet 16, thereby taking away the heat in the second gas interlayer 7, that is, taking away the heat of the outer tube 4, so that the heat storage layer 5 is cooled quickly.

[0049] In the cooling water interlayer 8, cooling water enters the cooling water interlayer 8 from the water inlet 17 at a certain flow rate and leaves from the water outlet 18, thereby taking away the heat in the cooling water interlayer 8, that is, taking away the heat of the heat storage layer 5, so that the shell 9 is cooled quickly.

[0050] In this embodiment, the heating furnace further comprises a partition, which is arranged between the heat storage layer 5 and the cooling water interlayer 8. Preferably, the partition is a stainless steel plate.

[0051] Preferably, the inner tube 1 in this embodiment is made of corundum. Selecting a high-temperature resistant corundum tube as the inner tube 1 can greatly withstand the heating temperature in the furnace.

[0052] There are two optional methods for securing the heating element 2 to the outer wall of the inner tube 1: The first is to provide a spiral groove on the outer wall of the inner tube 1 to support the heating element 2; the second is to provide a support frame on the outer wall of the inner tube 1, with a slot on the support frame to support the heating element 2. The first method is preferred in this embodiment. Preferably, the upper end of the heating element 2 is led out of the rectangular groove on the furnace cover 10, and the lower end of the heating element 2 is led out of the rectangular groove on the furnace bottom 11, and each is connected to a control power supply.

[0053] Optionally, the heating element 2 is a platinum wire or a platinum-rhodium wire. Preferably, the diameter of the platinum wire or platinum-rhodium wire is 0.5 mm to 5 mm, more preferably 1 mm to 3 mm. Even more preferably, when the heating element 2 is a platinum-rhodium wire, the ratio of platinum to rhodium in the platinum-rhodium wire can be 7:3 or 8:2. In this embodiment, the heating element 2 is preferably a platinum wire with a diameter of 1.5 mm.

[0054] Optionally, the thermal insulation coating 3 is an alloy coating of one or both of platinum and rhodium. Since the heat transfer mode under high temperature conditions (above 500°C) is mainly infrared radiation, the thermal insulation coating 3 on the outside of the inner tube 1 can effectively reflect the infrared radiation from the heating element 2 to the center of the inner tube 1 to achieve the purpose of heat preservation. In this embodiment, the thermal insulation coating 3 is preferably a platinum coating layer. Further preferably, the thickness of the thermal insulation coating 3 is 5nm-500nm, for example, 5.02nm-496nm, 8nm-460nm, 15nm-421nm, 40nm-400nm, 53nm-375nm, 80nm-340nm, 120nm-318nm, 148nm-300nm, 180nm-264nm, 234nm, etc., among which 20nm-100nm is further preferred. The thickness of the thermal insulation coating 3 in this embodiment is preferably 20nm.

[0055] Preferably, the distance between the thermal insulation coating 3 and the heating element 2 is 5 mm-50 mm.

[0056] Optionally, the heat storage layer 5 is made of one or more of aluminum silicate refractory fiber cotton, glass fiber cotton, and ceramic fiber cotton. Ceramic fiber cotton is preferred. Further preferably, the thickness of the heat storage layer 5 is 20 mm.

[0057] Optionally, the furnace bottom 11 and the furnace cover 10 are made of a mixture of one or more of high-temperature resistant ceramics, high-purity alumina, high-purity magnesia, and metallic aluminum. Preferably, the furnace bottom 11 and the furnace cover 10 have smooth surfaces.

[0058] In this embodiment, air flows through the first and second gas interlayers 6, 7 as a cooling medium. The first and second gas inlets 13, 15 are connected to an external air compressor to provide air. Optionally, the air temperature is room temperature (25°C), and the flow rate range is 0 ml / min to 2000 ml / min, which can be adjusted based on actual conditions.

[0059] Water as a cooling medium flows in the cooling water interlayer 8. Optionally, the water temperature is room temperature, and the flow rate range is 0 ml / min-1000 ml / min, which is adjusted according to actual conditions.

[0060] The heating furnace in this embodiment can quickly heat up and cool down. Its maximum heating power is 1500W, the maximum heating temperature is 1600℃, the heating rate is 5℃ / min-300℃ / min, and it takes about 5 minutes to heat up from room temperature to 1600℃, with an error of less than 1℃. The cooling rate is programmable and can be as high as 500℃ / min. It takes about 3 minutes to cool from 1600℃ to room temperature, and a constant temperature reaction can be performed at 1500℃. When the operating temperature is 1500℃, the outer wall temperature of the heating furnace is not higher than 65℃. It should be noted that the maximum heating temperature and heating rate of the heating furnace are related to the outer diameter and height of the inner tube 1, as well as the diameter and length of the heating element 2. In this embodiment, the inner tube 1 has a diameter of 30mm and a height of 300mm, and the outer tube 4 has a diameter of 42mm and a height of 300mm.

[0061] In this embodiment, the control device 19 can be a centralized or distributed controller. For example, the control device 19 can be a single single-chip microcomputer or a distributed plurality of single-chip microcomputers. The control program can be run in the single-chip microcomputer to control the thermocouple 12, air compressor and other structures to realize their functions.

[0062] The above embodiments merely illustrate the basic principles and features of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A heating furnace, characterized in that: include: A furnace body having a receiving cavity; An inner tube (1) is arranged in the accommodating cavity, and the inner cavity of the inner tube (1) is a heating reaction zone; A heating element (2) is wound around the outer wall of the inner tube (1); an outer tube (4) disposed in the accommodating cavity and sleeved on the outer circumference of the inner tube (1) at intervals, with a first gas interlayer (6) being formed between the outer tube (4) and the heating element (2); a heat-insulating coating (3) applied to the inner wall of the outer tube (4), the heat-insulating coating (3) being used to reflect heat generated by the heating element (2); A heat storage layer (5) is arranged in the accommodating cavity and is spaced apart and sleeved on the outer circumference of the outer tube (4); a second gas interlayer (7) is provided between the heat storage layer (5) and the outer tube (4); and a cooling water interlayer (8) is provided between the heat storage layer (5) and the inner wall of the furnace body; The furnace body comprises: A housing (9), wherein the housing (9) is annular; a furnace cover (10) sealed and connected to the top of the housing (9); a furnace bottom (11) sealed to the bottom of the shell (9); A first gas inlet (13) is provided on the furnace bottom (11) corresponding to the first gas interlayer (6), and a first gas outlet (14) is provided on the furnace cover (10) corresponding to the first gas interlayer (6); A second gas inlet (15) is provided on the furnace bottom (11) corresponding to the second gas interlayer (7), and a second gas outlet (16) is provided on the furnace cover (10) corresponding to the second gas interlayer (7); A water inlet (17) is provided on the furnace bottom (11) corresponding to the cooling water interlayer (8), and a water outlet (18) is provided on the furnace cover (10) corresponding to the cooling water interlayer (8); The distance between the thermal insulation coating (3) and the heating element (2) is 5 mm to 50 mm.

2. The heating furnace according to claim 1, characterized in that The heating furnace also includes: A thermocouple (12), one end of which passes through the furnace cover (10) and is inserted into the heating reaction zone, and the other end of which extends out of the furnace cover (10) and is electrically connected to a control device (19).

3. The heating furnace according to claim 1, characterized in that The inner surface of the furnace cover (10) is provided with a first fixing groove, a second fixing groove and a third fixing groove in sequence from the center to the periphery, which are used to fix the top end of the inner tube (1), the top end of the outer tube (4) and the top end of the heat storage layer (5), respectively; The inner surface of the furnace bottom (11) is provided with a fourth fixing groove arranged opposite to the first fixing groove, a fifth fixing groove arranged opposite to the second fixing groove, and a sixth fixing groove arranged opposite to the third fixing groove in sequence from the center to the periphery. The fourth fixing groove, the fifth fixing groove, and the sixth fixing groove are used to fix the bottom end of the inner tube (1), the bottom end of the outer tube (4), and the bottom end of the heat storage layer (5), respectively.

4. The heating furnace according to claim 1, characterized in that The heating furnace also includes: A partition is provided between the heat storage layer (5) and the cooling water interlayer (8).

5. The heating furnace according to claim 1, characterized in that The inner tube (1) is made of corundum.

6. The heating furnace according to claim 1, characterized in that The heating element (2) is a platinum wire or a platinum-rhodium wire.

7. The heating furnace according to claim 1, characterized in that The thermal insulation coating (3) is made of one of platinum and rhodium.

8. The heating furnace according to claim 1, characterized in that The heat storage layer (5) is made of one of aluminum silicate refractory fiber cotton, glass fiber cotton, and ceramic fiber cotton.

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