Fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tube and system thereof

Abstract

The invention relates to the technical field of fifteen-tube reduction furnaces, in particular to a fifteen-tube reduction furnace equipped with a cast heat-resistant steel large-diameter furnace tube, which comprises a furnace body, a sealing heat preservation mechanism, a furnace tube door switch, a hydrogen outlet connecting tube, a leaching tower, an upper furnace tube, a lower furnace tube, a connecting mechanism and a busbar device, a sealing heat preservation mechanism capable of guaranteeing temperature uniformity of any section in the furnace body is arranged in the furnace body, a leaching tower is installed at the lower end of the hydrogen outlet connecting pipe, an upper furnace pipe is installed at the side end of the tail of the furnace body, a lower furnace pipe is installed below the upper furnace pipe, connecting mechanisms are arranged on the outer sides of the upper furnace pipe and the lower furnace pipe, and each connecting mechanism comprises a lap joint flange and a red copper pad. A unique furnace body structural design is adopted, the special furnace body structural design is beneficial to uniformity of furnace temperature, product particles are uniform in distribution and high in quality, the product is designed in a full-automatic mode, the furnace head and the furnace tail are controlled by a high-temperature-resistant air cylinder to open a cover, the production efficiency is greatly improved in cooperation with a feeding and charging device, and the automation degree of the equipment is high.

Description

Technical Field

[0001] The invention relates to the technical field of fifteen-tube reduction furnaces, and in particular to a fifteen-tube reduction furnace equipped with large-diameter furnace tubes made of cast heat-resistant steel and a system thereof. Background Art

[0002] The domestic tungsten carbide processing industry involves the secondary reduction process for preparing tungsten powder. Multi-tube furnace equipment is usually used to reduce it to tungsten powder. Among them, the fifteen-tube furnace is a relatively traditional and widely recognized reduction furnace equipment. The fifteen-tube reduction furnace uses hydrogen as the reducing gas. It is a large-scale advanced equipment that recovers tungsten oxide powder materials under the conditions of designed process temperature. It is used to produce various ultra-fine, fine, medium and coarse particles of high-quality tungsten powder. It is the first choice device in the process of reducing tungsten powder and is currently widely used by large-scale enterprises in the field of tungsten powder production.

[0003] The tubes of the fifteen-tube furnace currently used in China usually have a small cross-sectional area, low production efficiency, high energy consumption, and low production capacity that cannot keep up with modern production needs. The factors affecting quality, such as reduction temperature, hydrogen quality and flow rate, boat loading and boat pushing speed, have poor stability and need to be improved in order to produce high-quality and multi-variety tungsten powder. If the furnace temperature zone control is not sensitive, the product quality cannot be effectively guaranteed; the insulation effect is not ideal, and the surface temperature of the furnace shell is high. In addition, the furnace body will produce certain deformation when the equipment is heated, and relevant control and protection structures are required.

[0004] Therefore, in view of the problems that the furnace tubes of the above-mentioned fifteen-tube furnace usually have a small cross-sectional area, low production efficiency, high energy consumption, and low production capacity that cannot keep up with modern production needs, as well as insensitive temperature zone control, unsatisfactory insulation effect, and high furnace shell surface temperature, a fifteen-tube reduction furnace equipped with large-diameter furnace tubes made of cast heat-resistant steel can be designed, which is suitable for the production of medium-coarse particle tungsten powder and can solve product quality problems at one stroke. Summary of the invention

[0005] In order to overcome the problems of high energy consumption, insensitive temperature zone control and unsatisfactory insulation effect of traditional fifteen-tube furnace.

[0006] The technical scheme of the present invention is as follows: a 15-tube reduction furnace equipped with a cast heat-resistant steel large-diameter furnace tube comprises a furnace body, a sealing and heat-insulating mechanism, a furnace tube door switch, a hydrogen outlet connecting pipe, a leaching tower, an upper furnace tube, a lower furnace tube, a connecting mechanism and a bus device; a sealing and heat-insulating mechanism is arranged inside the furnace body to ensure the temperature uniformity of any cross section inside the furnace body, a furnace tube door switch is arranged on the side end of the furnace body head, a hydrogen outlet connecting pipe is arranged on the lower end of the furnace body head, a leaching tower is arranged on the lower end of the hydrogen outlet connecting pipe, an upper furnace tube is arranged on the side end of the furnace body tail, a lower furnace tube is arranged below the upper furnace tube, connecting mechanisms are arranged on the outer sides of the upper furnace tube and the lower furnace tube, the upper furnace tube and the lower furnace tube are divided into three parts: a head part, a middle part and a tail part, and the connecting mechanism comprises a slip-on flange and a copper pad; the head part, the middle part and the tail part of the upper furnace tube and the lower furnace tube are detachably connected through a slip-on flange, a copper pad which is sealed and fitted with the connection between the upper furnace tube and the lower furnace tube is arranged on the outer side of the slip-on flange, and the number of the slip-on flange and the copper pad can be synchronously adjusted and set according to design requirements.

[0007] Preferably, the furnace body includes a furnace shell, and the sealing and insulation mechanism includes head bricks, compressed ceramic fiber modules and furnace bottom bricks; head bricks are installed on the outer sides of the upper furnace tube and the lower furnace tube, a compressed ceramic fiber module is provided on the inner wall of the furnace shell, and furnace bottom bricks are installed at the bottom end of the furnace shell.

[0008] Preferably, the upper furnace tube and the lower furnace tube are circular, with a total of 15 tubes and a diameter of 174 mm. Hydrogen vortex is generated inside, which is beneficial to the reduction reaction. The whole is made of cast heat-resistant steel with a temperature resistance of more than 1250°C. It is centrifugally cast with small deformation and long service life. Its main components can ensure safe and reliable operation of the equipment at a low maintenance cost.

[0009] Preferably, a furnace head pipe support frame is installed at the bottom end of the furnace head, and a furnace tail pipe support frame is installed at the bottom end of the furnace tail.

[0010] Preferably, an upper bracket for the furnace tail pipe is installed on the outer side of the furnace body rear end near the upper furnace pipe, and a lower bracket for the furnace tail pipe is installed on the outer side of the furnace body rear end near the lower furnace pipe.

[0011] A system of a fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes, characterized in that it includes the fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes as described above, and also includes a heating temperature control system, a pneumatic control system, a spray system, and a busbar system; The heating and temperature control system includes a heating element, a temperature-controlling thermocouple, a heating zone and a control device. The heating zone is divided into upper, middle and lower layers, a total of 5 areas. The furnace body is insulated with high-quality refractory materials. The refractory insulation material wraps the heating element and furnace bricks all around. Insulation cotton felt is added around to enhance the insulation effect. The temperature-controlling thermocouple is connected to the control device to monitor the furnace temperature in real time and adjust the heating power to ensure the uniformity of the furnace temperature field. The pneumatic control system includes a high temperature resistant cylinder, which can control the rapid and automatic opening of the furnace head and furnace tail; The spray system is arranged inside the leaching tower, which includes a back pressure water tank and a gas-water separator. The leaching tower 5 is a multi-layer leaching structure. The water level in the back pressure water tank is adjustable. A gas-water separator is installed at the gas outlet of the leaching tower. The spray system can process the gas discharged from the furnace tube. Through the multi-layer leaching of the leaching tower, the back pressure water tank adjusts the pressure, and the gas-water separator separates the gas and water to ensure that the discharged gas meets the environmental protection requirements. The bus system is arranged inside the bus device, which includes two hydrogen circuits and one nitrogen circuit. The hydrogen circuit includes a hydrogen outlet connecting pipe and a hydrogen inlet device, and the nitrogen circuit includes a nitrogen inlet device and a flow meter. The flow rate is adjusted separately by the flow meter. The nitrogen circuit drives away the air inside the furnace tube when shutting down and restarting to avoid hydrogen-air mixing and explosion.

[0012] Preferably, the spray system can process the gas exhausted from the furnace tube, through multi-layer elution in the elution tower, pressure adjustment in the back-pressure water tank, and separation of gas and water in the gas-water separator, to ensure that the exhausted gas meets environmental protection requirements.

[0013] Preferably, the high temperature resistant cylinder and the furnace tube door switch are connected to realize the cover opening operation of the furnace head and furnace tail, while ensuring the stability and sealing of the furnace body.

[0014] Beneficial effects of the present invention: 1. The present invention adopts a unique furnace body structure design. The special furnace body structure design is conducive to the uniformity of furnace temperature, ensuring that the temperature uniformity of any cross section in the furnace is within 10°C, and the peak temperature of any single tube does not exceed the set value of 20°C, so as to achieve a good temperature difference in each zone, uniform distribution of product particles and high quality. This product is designed in accordance with full automation. The opening of the furnace head and furnace tail is controlled by a high-temperature resistant cylinder, and the feeding and charging device greatly improves the production efficiency. The equipment has a high degree of automation, reduces the labor intensity of operators, and is conducive to the stability of product quality. The furnace body is insulated with high-quality refractory materials. Compared with traditional furnace types, it greatly improves the insulation effect, saves electricity, has high production efficiency, large production capacity, and low energy consumption for long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The overall cross-sectional view of the fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes of the present invention is shown; Figure 2 The overall stereogram of the fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes of the present invention is shown; Figure 3 Shown is a cross-sectional view of the sealing and heat-insulating mechanism in a fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes of the present invention.

[0016] Explanation of the reference numerals: 1. furnace body; 3. furnace tube door switch; 4. hydrogen outlet connecting pipe; 5. elution tower; 6. upper furnace tube; 7. lower furnace tube; 9. busbar device; 10. furnace head tube support frame; 11. furnace tail tube support frame; 12. furnace tail tube upper clamping frame; 13. furnace tail tube lower clamping frame; 101. furnace shell; 201. head brick; 202. compressed ceramic fiber module; 203. furnace bottom brick; 801. slip-on flange; 802. copper pad. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] See also Figure 1-Figure 2 The present invention provides an embodiment: a 15-tube reduction furnace equipped with a cast heat-resistant steel large-diameter furnace tube, comprising a furnace body 1, a sealing and heat-insulating mechanism, a furnace tube door switch 3, a hydrogen outlet connecting pipe 4, a leaching tower 5, an upper furnace tube 6, a lower furnace tube 7, a connecting mechanism and a bus device 9; the furnace body 1 is provided with a sealing and heat-insulating mechanism that can ensure the temperature uniformity of any cross section inside the furnace body 1, the furnace tube door switch 3 is installed at the side end of the head of the furnace body 1, the hydrogen outlet connecting pipe 4 is installed at the lower end of the head of the furnace body 1, and the leaching tower 5 is installed at the lower end of the hydrogen outlet connecting pipe 4 An upper furnace tube 6 is installed at the rear side end of the furnace body 1, and a lower furnace tube 7 is installed below the upper furnace tube 6. A connecting mechanism is provided on the outer sides of the upper furnace tube 6 and the lower furnace tube 7. The upper furnace tube 6 and the lower furnace tube 7 are divided into three parts: a head, a middle, and a tail. The connecting mechanism includes a slip-on flange 801 and a copper pad 802. The head, middle, and tail parts of the upper furnace tube 6 and the lower furnace tube 7 are detachably connected through a slip-on flange 801. A copper pad 802 is provided on the outer side of the slip-on flange 801, which is sealed and fitted with the connection between the upper furnace tube 6 and the lower furnace tube 7. The slip-on flange 801 The number of copper pads 802 can be adjusted and set synchronously according to design requirements. The furnace body 1 includes a furnace shell 101. The sealing and heat-insulating mechanism includes a head brick 201, a compressed ceramic fiber module 202 and a furnace bottom brick 203. The upper furnace tube 6 and the lower furnace tube 7 are installed with a head brick 201 on the outside, and the compressed ceramic fiber module 202 is provided on the inner wall of the furnace shell 101. The furnace bottom brick 203 is installed at the bottom end of the furnace shell 101. The upper furnace tube 6 and the lower furnace tube 7 are circular, with a total of 15 tubes, a diameter of 174 mm, and the inner The generation of hydrogen eddy current is beneficial to the reduction reaction. The whole is made of cast heat-resistant steel with a temperature resistance of more than 1250°C. It is centrifugally cast and has small deformation and long service life. Its main components can ensure safe and reliable operation of the equipment at a low maintenance cost. A furnace head pipe support frame 10 is installed at the bottom end of the head of the furnace body 1, a furnace tail pipe support frame 11 is installed at the bottom end of the rear of the furnace body 1, an upper furnace tail pipe bracket 12 is installed on the outer side of the rear of the furnace body 1 near the upper furnace pipe 6, and a lower furnace tail pipe bracket 13 is installed on the outer side of the rear of the furnace body 1 near the lower furnace pipe 7.

[0019] A system of a fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes, characterized in that it includes the fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes as described above, and also includes a heating temperature control system, a pneumatic control system, a spray system, and a busbar system; The heating and temperature control system includes a heating element, a temperature control thermocouple, a heating zone and a control device. The heating zone is divided into upper, middle and lower layers, a total of 5 areas. The furnace body 1 is entirely insulated with high-quality refractory materials. The refractory insulation material wraps the heating element and furnace bricks all around. Insulation cotton felt is added around to enhance the insulation effect. The temperature control thermocouple is connected to the control device to monitor the furnace temperature in real time and adjust the heating power to ensure the uniformity of the furnace temperature field. The pneumatic control system includes a high temperature resistant cylinder, which is connected to the furnace tube door switch 3. The high temperature resistant cylinder can control the furnace head and furnace tail to open the cover quickly and automatically, while ensuring the stability and sealing of the furnace body 1; The spray system is arranged inside the leaching tower 5, which includes a back-pressure water tank and a gas-water separator. The leaching tower 5 is a multi-layer leaching structure. The water level in the back-pressure water tank is adjustable. The gas-water separator is installed at the gas outlet of the leaching tower 5. The spray system can process the gas discharged from the furnace tube, and the back-pressure water tank adjusts the pressure through the multi-layer leaching of the leaching tower 5. The gas-water separator separates the gas and water to ensure that the discharged gas meets the environmental protection requirements. The bus system is arranged inside the bus device 9, which includes two hydrogen circuits and one nitrogen circuit. The hydrogen circuit includes a hydrogen outlet connecting pipe 4 and a hydrogen inlet device, and the nitrogen circuit includes a nitrogen inlet device and a flow meter. The flow rate is adjusted separately by the flow meter. The nitrogen circuit drives away the air inside the furnace tube when the furnace is shut down and restarted to avoid hydrogen-air mixing and explosion.

[0020] When the reduction reaction needs to start, the heating temperature control system is first started, the heating element starts to heat, and the temperature in the furnace body 1 is monitored in real time by the temperature control thermocouple, and the data is fed back to the control device. The control device adjusts the heating power according to the preset temperature curve or real-time temperature data to ensure that the temperature in the furnace body 1 reaches the required reduction temperature uniformly and stably; While heating, hydrogen enters the furnace tube through the hydrogen inlet device. Since the interior of the furnace tube is designed to generate a hydrogen vortex, hydrogen forms a vortex in the upper furnace tube 6 and the lower furnace tube 7, which is beneficial to the reduction reaction. The hydrogen circulates in the upper furnace tube 6 and the lower furnace tube 7, fully contacts with the material to be reduced, and performs a reduction reaction. Under the action of high temperature and hydrogen, the material to be reduced undergoes a reduction reaction to generate the desired product. The waste gas generated during the reaction is discharged from the furnace body 1 through the hydrogen outlet connecting pipe 4. The waste gas includes unreacted hydrogen and other gases, which are discharged from the furnace body 1 through the hydrogen outlet connecting pipe 4. The discharged waste gas enters the elution tower 5 for multi-layer elution treatment. The elution tower 5 is provided with a back pressure water tank and a gas-water separator. By adjusting the water level in the back pressure water tank and the number of elution layers, it can be ensured that harmful gases and moisture in the waste gas are effectively removed. The treated waste gas meets environmental protection requirements and is then discharged through the gas outlet of the elution tower 5. When it is necessary to add materials or take out products, the high temperature resistant cylinder is controlled by the pneumatic control system to realize the rapid and automatic opening operation of the furnace head and furnace tail. The design of the furnace tube door switch 3 ensures the stability and sealing of the furnace body 1, and will not leak high temperature gas or affect the temperature uniformity in the furnace during operation; When the furnace is shut down and restarted or when it is necessary to protect the inside of the furnace tube from the influence of air, the nitrogen circuit is started, and the nitrogen enters the furnace tube through the nitrogen intake device to drive away the air inside the furnace tube to avoid explosion caused by mixing of hydrogen and air.

[0021] Through the above steps, a special furnace body structure design is set to facilitate the uniformity of furnace temperature, ensure that the temperature uniformity of any cross section in the furnace is within 10°C, and the peak temperature of any single tube does not exceed the set value of 20°C, so as to achieve good temperature difference in each zone, uniform distribution of product particles, high quality, and fully automated design. The opening of the furnace head and furnace tail is controlled by a high-temperature resistant cylinder, and the production efficiency is greatly improved in conjunction with the feeding and charging device, so as to solve the problems of high energy consumption of the traditional fifteen-tube furnace, insensitive temperature zone control, and unsatisfactory insulation effect.

[0022] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of those skilled in the art without departing from the spirit of the present invention.

Claims

1. A 15-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes, comprising a furnace body (1); characterized in that: The furnace body (1) also includes a sealing and heat-insulating mechanism, a furnace tube door switch (3), a hydrogen outlet connecting pipe (4), a leaching tower (5), an upper furnace tube (6), a lower furnace tube (7), a connecting mechanism and a busbar device (9); the furnace body (1) is provided with a sealing and heat-insulating mechanism capable of ensuring the uniformity of temperature in any cross section of the furnace body (1); a furnace tube door switch (3) is installed at the head side end of the furnace body (1); a hydrogen outlet connecting pipe (4) is installed at the lower end of the head of the furnace body (1); a leaching tower (5) is installed at the lower end of the hydrogen outlet connecting pipe (4); an upper furnace tube (6) is installed at the tail side end of the furnace body (1); 6), a lower furnace tube (7) is installed below the upper furnace tube (6), and connecting mechanisms are provided on the outer sides of the upper furnace tube (6) and the lower furnace tube (7). The upper furnace tube (6) and the lower furnace tube (7) are divided into three parts: a head, a middle, and a tail. The connecting mechanism includes a slip-on flange (801) and a copper pad (802); the head, the middle, and the tail of the upper furnace tube (6) and the lower furnace tube (7) are detachably connected through the slip-on flange (801), and the outer side of the slip-on flange (801) is provided with a copper pad (802) that is sealed and fitted with the connection between the upper furnace tube (6) and the lower furnace tube (7).

2. The fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 1, characterized in that: The furnace body (1) comprises a furnace shell (101); the sealing and heat-insulating mechanism comprises a head brick (201), a compressed ceramic fiber module (202) and a furnace bottom brick (203); the head brick (201) is installed on the outer side of the upper furnace tube (6) and the lower furnace tube (7); the compressed ceramic fiber module (202) is provided on the inner side wall of the furnace shell (101); and the furnace bottom brick (203) is installed at the bottom end of the furnace shell (101).

3. The fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 1, characterized in that: The upper furnace tube (6) and the lower furnace tube (7) are circular, with a total of (15) tubes and a diameter of (174) mm. A hydrogen vortex is generated inside the tube, which is beneficial to the reduction reaction. The entire tube is made of cast heat-resistant steel with a temperature resistance of more than (1250) ° C. It is formed by centrifugal casting.

4. The fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 1, characterized in that: A furnace head pipe support frame (10) is installed at the bottom end of the head of the furnace body (1), and a furnace tail pipe support frame (11) is installed at the bottom end of the tail of the furnace body (1).

5. The fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 1, characterized in that: An upper furnace tail pipe bracket (12) is installed on the outer side of the rear end of the furnace body (1) near the upper furnace pipe (6), and a lower furnace tail pipe bracket (13) is installed on the outer side of the rear end of the furnace body (1) near the lower furnace pipe (7).

6. A system of 15-tube reduction furnaces equipped with cast heat-resistant steel large-diameter furnace tubes, characterized in that It comprises a 15-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 5, which also includes a heating temperature control system, a pneumatic control system, a spray system, and a busbar system; The heating and temperature control system includes a heating element, a temperature control thermocouple, a heating zone and a control device. The heating zone is divided into an upper layer, a middle layer and a lower layer, a total of 5 zones. The furnace body (1) is entirely insulated with high-quality refractory materials. The refractory insulation material fully wraps the heating element and furnace bricks. Insulation cotton felt is added around to enhance the insulation effect. The temperature control thermocouple is connected to the control device to monitor the furnace temperature in real time and adjust the heating power, thereby ensuring the uniformity of the furnace temperature field. The pneumatic control system includes a high temperature resistant cylinder, which can control the rapid and automatic opening of the furnace head and furnace tail; The spray system is arranged inside the leaching tower (5), and comprises a back-pressure water tank and a gas-water separator. The leaching tower (5) is a multi-layer leaching structure, the water level in the back-pressure water tank is adjustable, and the gas-water separator is installed at the gas outlet of the leaching tower (5); The busbar system is arranged inside the busbar device (9), and includes two hydrogen circuits and one nitrogen circuit. The hydrogen circuit includes a hydrogen outlet connecting pipe (4) and a hydrogen inlet device. The nitrogen circuit includes a nitrogen inlet device and a flow meter. The flow rate is adjusted separately by the flow meter. When the nitrogen circuit is shut down and restarted, the air inside the furnace tube is driven away to prevent hydrogen and air from mixing and exploding.

7. The system of the fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 6, characterized in that: The spray system can process the gas discharged from the furnace tube, through multi-layer elution in the elution tower (5), pressure adjustment in the back pressure water tank, and separation of gas and water in the gas-water separator, so as to ensure that the discharged gas meets environmental protection requirements.

8. The system of the fifteen-tube reduction furnace equipped with cast heat-resistant steel large-diameter furnace tubes according to claim 6, characterized in that: The high temperature resistant cylinder is connected to the furnace tube door switch (3), so that the cover opening operation of the furnace head and furnace tail can be realized, while ensuring the stability and sealing of the furnace body (1).

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