Graphite column microwave high-temperature reduction device and method

Abstract

The invention relates to the technical field of preparation of diamond raw materials, and discloses a graphite column microwave high-temperature reduction device which comprises a vertical tube furnace, a graphite column microwave high-temperature reduction device, a graphite column microwave high-temperature reduction device and a graphite column microwave high-temperature reduction device, and the vertical tube furnace is internally provided with a tube furnace chamber and an isolation chamber; the cabin body plate is arranged on the outer wall of the vertical tube furnace; the furnace tube is arranged in the tube furnace chamber; wherein the two ends of the furnace tube are integrally communicated with the isolation cavity, and graphite trays are fixedly mounted at the top and the bottom of the inner wall of the furnace tube. And the high-temperature constant-temperature reduction time is shortened from 8 hours to 90 minutes. The traditional vacuum furnace reduction process is adopted, the required electricity consumption for reducing one ton of graphite columns is 3630 DEG C, the microwave high-temperature reduction process is adopted, 14 hours are required for producing one ton of graphite columns, the power consumption is 95kw / h * 14 hours = 1330 DEG C, the electric quantity is saved by half compared with that of the traditional process, the efficiency is high, energy is saved, the traditional vacuum furnace reduction process is replaced, and the effects of improving the efficiency and saving energy are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of diamond raw materials, in particular to a graphite column microwave high-temperature reduction device and method. Background Art

[0002] The conventional high-temperature reduction process of graphite columns uses a resistive vacuum furnace for high-temperature reduction. During the reduction process, a large amount of hydrogen and nitrogen must be introduced into the furnace. However, the following problems may occur: 1. Safety hazards: Hydrogen is a flammable and explosive gas, which requires high air tightness of the vacuum furnace and poses great safety hazards; 2. Low efficiency: The restoration time takes more than 12 hours, the labor intensity of employees is high, and the production efficiency is low; 3. Large loss of electrical components: graphite heating rods and graphite felt have large loss and a service life of about 6 months; 4. Large power consumption: Taking a vacuum furnace with a capacity of 150kg per furnace as an example, its maximum power is 90 kw, and the average power consumption is 50 kw / h. According to the 11-hour constant temperature to cooling time, the average power consumption per furnace is 50 kw / h*11h=550 degrees, and about 3630 degrees of electricity are required to process one ton of graphite column; 5. Average quality: The purity of the reduced graphite column reaches 99.99%, and the quality of the diamond used for synthesis is average.

[0003] Therefore, in order to eliminate potential safety hazards, reduce labor intensity, improve product quality, and increase production efficiency, we provide a graphite column microwave high-temperature reduction device and method. Summary of the invention

[0004] The purpose of the present invention is to provide a graphite column microwave high-temperature reduction device and method, so as to eliminate potential safety hazards, reduce labor intensity, improve product quality and improve production efficiency.

[0005] To achieve the above object, the present invention provides the following technical solution: a graphite column microwave high temperature reduction device, comprising: A vertical tube furnace, wherein a tube furnace chamber and an isolation chamber are provided inside the vertical tube furnace; A cabin plate disposed on the outer wall of the vertical tube furnace; A furnace tube disposed inside the tube furnace chamber; Wherein, both ends of the furnace tube are connected to the isolation chamber in an integrated manner, and graphite trays are fixedly installed on the top and bottom of the inner wall of the furnace tube; a high-temperature reduction treatment component disposed on the vertical tube furnace; Wherein, the high-temperature reduction treatment component includes a conveying part arranged at the top of the vertical tube furnace and an output part arranged at the bottom of the vertical tube furnace.

[0006] Preferably, the conveying part includes a pneumatic conveyor, a pneumatic conveying pipe 1, a preheater, and a pneumatic conveying pipe 2. The pneumatic conveyor is connected to the preheater through the pneumatic conveying pipe 1, and the preheater is connected to the top of the furnace tube located at the top through the pneumatic conveying pipe 2.

[0007] Preferably, the output part includes an output pipe, a heat exchanger, and a separation collector. One end of the output pipe is connected to the bottom end of the furnace tube located at the bottom, and the other end of the output pipe is connected to the separation collector through the heat exchanger. A pressure gauge is provided on the top of the separation collector.

[0008] A graphite column microwave high temperature reduction method, the method comprising the following steps: Step 1: introduce weak reducing gas into the vertical tube furnace part and the outside of the insulation layer of the microwave reduction equipment to maintain a slight positive pressure in the cabin; Step 2: Place the graphite column on a graphite tray and place it on the return plate line outside the microwave equipment, and then transfer it to the inner chamber of the microwave reduction furnace through the double buffer chamber of the return plate line; Step 3: In the first stage, the temperature is raised to 550°C and kept constant for 90 minutes; Step 4: In the second stage, the temperature is raised to 1000°C and kept constant for 90 minutes; Step 5: In the third stage, the temperature is raised to 1200°C and kept constant for 90 minutes; Step 6: Enter the slow cooling stage, cool naturally for 60 minutes, and the graphite column drops to 850°C; Step 7: Enter the forced cooling section, the cooling time is 240 minutes, and the graphite column is cooled to 50-60℃; Step 8: After the reduction process is completed, the graphite column flows through the return line buffer hatch to the external return line, is collected in a container, and then vacuum-packed, and the process is completed.

[0009] Preferably, the specified pressure is controlled at -60 to -100 kPa.

[0010] Preferably, the furnace heating rate is increased to 800-1300°C at a heating rate not exceeding 5°C / min.

[0011] The present invention provides a graphite column microwave high temperature reduction device and method, which has the following beneficial effects: (1) The present invention plays a safety role by introducing weak reducing gas into the furnace to maintain a slight positive pressure. The weak reducing gas used in the present invention does not have an explosion risk and acts as a reducing agent and protective gas during the high-temperature reduction process.

[0012] (2) The present invention shortens the high-temperature constant temperature reduction time from 8 hours to 90 minutes. With the traditional vacuum furnace reduction process, the power consumption required for reducing one ton of graphite columns is 3630 degrees. With the microwave high-temperature reduction process, it takes 14 hours to produce one ton of graphite columns, and the power consumption is 95kw / h*14 hours=1330 degrees. Compared with the traditional process, one ton of electricity is saved by half, and the efficiency is high and energy-saving. It replaces the traditional vacuum furnace reduction process and achieves the effect of improving efficiency and saving energy.

[0013] (3) The purity of the graphite column treated by the microwave high-temperature reduction process in the present invention is as high as 99.999%. The purity of the graphite column treated by the vacuum furnace high-temperature reduction process is 99.99%, which replaces the traditional vacuum furnace reduction process and improves the quality effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a bottom view of the overall structure of the present invention; Figure 3 It is a cross-sectional view of the vertical tube furnace of the present invention; Figure 4 For the present invention Figure 3 A magnified view of center.

[0015] In the figure: 111 vertical tube furnace, 112 cabin plate, 113 tube furnace chamber, 114 isolation chamber, 115 furnace tube, 116 graphite tray, 2 high temperature reduction treatment component, 21 conveying part, 211 pneumatic conveyor, 212 pneumatic conveying pipe 1, 213 preheater, 214 pneumatic conveying pipe 2, 22 output part, 221 output pipe, 222 heat exchanger, 223 separation collector, 224 pressure gauge. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0019] A preferred embodiment of a graphite column microwave high temperature reduction device and method provided by the present invention is as follows: Figure 1-4 As shown: A graphite column microwave high temperature reduction device, comprising: A vertical tube furnace 111, wherein a tube furnace chamber 113 and an isolation chamber 114 are provided inside the vertical tube furnace 111; A cabin plate 112 disposed on the outer wall of the vertical tube furnace 111; A furnace tube 115 disposed inside the tube furnace chamber 113; The two ends of the furnace tube 115 are connected to the isolation chamber 114 in an integrated manner, and the top and bottom of the inner wall of the furnace tube 115 are fixedly mounted with a graphite tray 116; A high-temperature reduction treatment component 2 disposed on the vertical tube furnace 111; The high temperature reduction treatment assembly 2 includes a conveying portion 21 disposed at the top of the vertical tube furnace 111 and an output portion 22 disposed at the bottom of the vertical tube furnace 111; The conveying part 21 includes a pneumatic conveyor 211, a pneumatic conveying pipe 1 212, a preheater 213, and a pneumatic conveying pipe 214. The pneumatic conveyor 211 is connected to the preheater 213 through the pneumatic conveying pipe 1 212, and the preheater 213 is connected to the top of the furnace tube 115 located at the top through the pneumatic conveying pipe 214. The output part 22 includes an output pipe 221, a heat exchanger 222, and a separation collector 223. One end of the output pipe 221 is connected to the bottom end of the furnace tube 115 located at the bottom, and the other end of the output pipe 221 is connected to the separation collector 223 through the heat exchanger 222. A pressure gauge 224 is provided on the top of the separation collector 223. Example

[0020] On the basis of Example 1, a preferred embodiment of a graphite column microwave high temperature reduction device and method provided by the present invention is as follows: Figure 1-4 As shown: the method comprises the following steps: Step 1: weak reducing gas is introduced into the vertical tube furnace 111 part of the microwave reduction equipment and the outside of the insulation layer to maintain a slight positive pressure in the cabin; Step 2: Put the graphite column on the graphite tray 116, and place it on the return plate line outside the microwave equipment, and then transfer it to the inner chamber of the microwave reduction furnace through the double buffer chamber of the return plate line; Step 3: In the first stage, the temperature is raised to 550°C and kept constant for 90 minutes; Step 4: In the second stage, the temperature is raised to 1000°C and kept constant for 90 minutes; Step 5: In the third stage, the temperature is raised to 1200°C and kept constant for 90 minutes; Step 6: Enter the slow cooling stage, cool naturally for 60 minutes, and the graphite column drops to 850°C; Step 7: Enter the forced cooling section, the cooling time is 240 minutes, and the graphite column is cooled to 50-60℃; Step 8: After the reduction process is completed, the graphite column flows through the return line buffer hatch to the external return line, is collected in a container, and then vacuum-packed, and the process is completed. The specified pressure is controlled at -60 to -100 kPa; the furnace temperature rises to 800-1300°C at a rate not exceeding 5°C / min.

[0021] When in use, firstly, the vertical tube furnace 111 is evacuated 1-3 times by a vacuum pump to a pressure of -100 to -60Pa, and the specified pressure is controlled at -60 to -100kPa. A weak reducing gas is introduced into the furnace to maintain a slightly positive pressure, which plays a role in safety. The weak reducing gas used in the present invention does not have an explosion risk, and acts as a reducing agent and protective gas in the high-temperature reduction process. The furnace is heated to 800-1300°C at a heating rate of no more than 5°C / min to avoid damage to the furnace tube due to excessive temperature changes; then, the pneumatic conveyor 211 and the preheater 213 are turned on to heat the introduced weak reducing gas. The graphite column is placed on the graphite tray 116 and placed on the outer return plate line of the microwave equipment, and is transported into the inner chamber of the microwave reduction furnace through the double buffer chamber of the return plate line. Finally, according to the first stage, the temperature is raised to 550°C and maintained at a constant temperature for 90 minutes; the second stage is raised to 1000°C and maintained at a constant temperature for 90 minutes; the third stage is raised to 1200°C and maintained at a constant temperature for 90 minutes; enters the slow cooling section, naturally cools for 60 minutes, and the graphite column drops to 850°C; enters the forced cooling section, the cooling time is 240 minutes, and the graphite column drops to 50-60°C; the reduction process is completed, the graphite column passes through the buffer hatch of the return plate line to the outer return plate line, is collected in a container, and then vacuum-packed, and the process is completed.

[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0023] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A graphite column microwave high temperature reduction device, characterized in that: Included are: A vertical tube furnace (111), wherein a tube furnace chamber (113) and an isolation chamber (114) are provided inside the vertical tube furnace (111); A cabin plate (112) arranged on the outer wall of the vertical tube furnace (111); A furnace tube (115) disposed inside the tube furnace chamber (113); Wherein, both ends of the furnace tube (115) are integrally connected to the isolation chamber (114), and graphite trays (116) are fixedly installed on the top and bottom of the inner wall of the furnace tube (115); A high-temperature reduction treatment component (2) disposed on the vertical tube furnace (111); The high-temperature reduction treatment component (2) comprises a conveying portion (21) arranged at the top of the vertical tube furnace (111) and an output portion (22) arranged at the bottom of the vertical tube furnace (111).

2. A graphite column microwave high temperature reduction device according to claim 1, characterized in that: The conveying portion (21) comprises a pneumatic conveyor (211), a first pneumatic conveying pipe (212), a preheater (213), and a second pneumatic conveying pipe (214); the pneumatic conveyor (211) is connected to the preheater (213) via the first pneumatic conveying pipe (212); and the preheater (213) is connected to the top of the furnace tube (115) located at the top via the second pneumatic conveying pipe (214).

3. The graphite column microwave high temperature reduction device according to claim 1, characterized in that: The output portion (22) comprises an output pipe (221), a heat exchanger (222), and a separation collector (223); one end of the output pipe (221) is connected to the bottom end of the furnace tube (115) located at the bottom, and the other end of the output pipe (221) is connected to the separation collector (223) via the heat exchanger (222); a pressure gauge (224) is provided on the top of the separation collector (223).

4. The method for high-temperature microwave reduction of graphite columns according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: Step 1: introducing weak reducing gas into the vertical tube furnace (111) and the outside of the insulation layer in the inner chamber of the microwave reduction equipment, so as to maintain a slight positive pressure in the chamber; Step 2: Place the graphite column on a graphite tray (116), and place it on the return plate line outside the microwave equipment, and transport it into the microwave reduction furnace through the double buffer bin of the return plate line; Step 3: In the first stage, the temperature is raised to 550°C and kept constant for 90 minutes; Step 4: In the second stage, the temperature is raised to 1000°C and kept constant for 90 minutes; Step 5: In the third stage, the temperature is raised to 1200°C and kept constant for 90 minutes; Step 6: Enter the slow cooling stage, cool naturally for 60 minutes, and the graphite column drops to 850°C; Step 7: Enter the forced cooling section, the cooling time is 240 minutes, and the graphite column is cooled to 50-60℃; Step 8: After the reduction process is completed, the graphite column flows through the return line buffer hatch to the external return line, is collected in a container, and then vacuum-packed, and the process is completed.

5. A graphite column microwave high temperature reduction device and method according to claim 4, characterized in that: The specified pressure is controlled at -60~-100kPa.

6. A graphite column microwave high temperature reduction device and method according to claim 4, characterized in that: The furnace temperature rises to 800-1300°C at a rate not exceeding 5°C / min.

Images