Apparatus and method for heat treatment of powder materials

Abstract

The application provides a device and method for heat treatment of powder material, and belongs to the technical field of heat treatment of powder material. The device comprises a powder heat treatment chamber, a heat exchanger, a fan, a high-pressure reaction gas tank and a flue. A powder feeding pipe is connected to one side of the upper part of the powder heat treatment chamber, and a powder discharging pipe is connected to one side of the lower part of the powder heat treatment chamber. A sintered porous filter plate is arranged at the upper part of the powder heat treatment chamber, and a sintered porous air distribution plate is arranged at the lower part of the powder heat treatment chamber. The top of the sintered porous filter plate is an upper air chamber, and the lower part of the sintered porous air distribution plate is a lower air chamber. An electric heating device is installed in the lower air chamber. The top of the powder heat treatment chamber is connected to the high-pressure reaction gas tank and the flue through pipelines. The heat exchanger is arranged on the external connecting pipeline between the top and the bottom of the powder heat treatment chamber. The fan is arranged on the external connecting pipeline between the gas inlet and the gas outlet of the heat exchanger. The device can improve the cleanliness and reactivity of the powder raw material, and improve the quality and production efficiency of the gas-solid reaction product.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology for powder materials, and more particularly to an apparatus and method for heat treatment of powder materials. Background Technology

[0002] In modern industrial production, numerous gas-solid reaction processes exist. To improve product quality and production efficiency, ultrafine powder solid particles are often used to react with gases. Because ultrafine powders have a large specific surface area, they easily absorb moisture and adsorb oxygen on their surface during storage. Therefore, before the gas-solid reaction process, the powder needs to be heat-treated to remove adsorbed moisture, reduce oxygen adsorption on the powder surface, and may even require pre-reaction between the solid particles and the reacting gases. This invention provides a process method and apparatus for the heat treatment of ultrafine powders. Summary of the Invention

[0003] This invention provides an apparatus and method for heat treatment of powder materials, which solves the problem of removing adsorbed moisture and impurity gases from powders before they enter the gas-solid reaction, and performs certain surface pretreatment to improve the cleanliness and reactivity of the powder raw materials, thereby improving the quality of gas-solid reaction products and production efficiency.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] An apparatus for heat treatment of powder materials includes N stages of powder material heat treatment units connected in series.

[0006] The powder material heat treatment unit includes a powder heat treatment chamber, a heat exchanger, a fan, a high-pressure reaction gas tank, and a flue.

[0007] A powder feed pipe is connected to the upper side of the powder heat treatment chamber, and a powder discharge pipe is connected to the lower side of the powder heat treatment chamber.

[0008] A sintered porous filter plate is installed in the upper part of the powder heat treatment chamber, and a sintered porous air distribution plate is installed in the lower part.

[0009] Powder material is filled between the sintered porous filter plate and the sintered porous air distribution plate;

[0010] The top of the sintered porous filter plate is an upper air chamber.

[0011] The lower part of the sintered porous air distribution plate is a lower air chamber, and an electric heating device is installed in the lower air chamber.

[0012] The gas inlet at the top of the powder heat treatment chamber is connected to a high-pressure reaction gas tank via a pipeline.

[0013] The gas outlet at the top of the powder heat treatment chamber is connected to a waste gas recovery device, a heat exchanger, and a flue via pipes.

[0014] The gas inlet at the bottom of the powder heat treatment chamber is connected to the gas outlet of the heat exchanger via a pipe.

[0015] The gas inlet of the heat exchanger is also connected to the gas outlet of the fan via a pipe, and the gas outlet of the fan is also connected to the flue via a pipe;

[0016] The blower gas inlet is connected to the reaction gas pipeline, the protective gas pipeline, and the heat exchanger gas outlet;

[0017] The gas outlet of the heat exchanger is also connected to the next powder material heat treatment unit.

[0018] The edges of the sintered porous filter plate and the sintered porous air distribution plate are attached to the inner wall of the powder heat treatment chamber, and the sintered pore diameter on the sintered porous filter plate and the sintered porous air distribution plate is smaller than the particle size of the powder.

[0019] N is not less than 1, a powder feed valve is provided on the powder feed pipe, and a powder discharge valve is provided on the powder discharge pipe.

[0020] The powder feed pipe is connected to the lower part of the sintered porous filter plate in the powder heat treatment chamber, and the powder discharge pipe is connected to the upper part of the sintered porous air distribution plate in the powder heat treatment chamber.

[0021] A solenoid valve is installed on the pipeline connecting the gas inlet at the top of the powder heat treatment chamber to the high-pressure reaction gas tank.

[0022] A valve seven is installed on the pipe connecting the gas outlet at the top of the powder heat treatment chamber to the waste gas recovery device. No valve is installed on the pipe connecting to the heat exchanger, and a valve six is ​​installed on the pipe connecting to the flue.

[0023] Valve 5 is installed on the pipe connecting the gas outlet of the blower and the flue; valve 4 is installed on the reaction gas pipe; valve 3 is installed on the protective gas pipe; valve 2 is installed on the pipe connecting the gas outlet of the heat exchanger to the next powder material heat treatment device; and valve 1 is installed on the pipe connecting the gas outlet of the heat exchanger to the gas inlet at the bottom of the powder heat treatment chamber.

[0024] The heat exchanger is a partitioned heat exchanger, the purpose of which is to keep the fan operating at a low temperature.

[0025] The application method of this device includes the following steps:

[0026] S1. Powder enters the powder heat treatment chamber through the powder feed pipe and the powder feed valve is closed. The reaction gas enters the lower air chamber and enters the powder material through the pores of the sintered porous air distribution plate. In the fluidized state, it replaces the air in the powder material layer. The replaced gas exits the powder heat treatment chamber after passing through the sintered porous filter plate and enters the waste gas recovery device or flue.

[0027] S2. After 10-60 minutes of room temperature reaction gas replacement, turn on the electric heating device and use medium temperature reaction gas at 200℃ to 300℃ to replace the moisture adsorbed by the powder material and the oxygen adsorbed on the surface of the powder particles.

[0028] S3. After purging with medium-temperature reaction gas for 1-2 hours, heat the powder to 1200℃-1450℃ with high-temperature reaction gas at 1100℃-1500℃ and maintain it for 0.2-10 hours to complete the heat treatment process.

[0029] S4. After the powder heat treatment process is completed, the electric heating device is turned off, and the hot powder is discharged from the powder discharge valve and enters the next process to achieve hot discharge.

[0030] or,

[0031] After the powder heat treatment process is completed, the electric heating device is turned off, and the high-temperature powder is cooled with room temperature protective gas. After cooling, the powder is discharged from the powder discharge valve, realizing low-temperature or room-temperature discharge.

[0032] In steps S2 and S3, the hot reaction gas exiting the powder heat treatment chamber through the sintered porous filter plate recovers heat through a heat exchanger and is then pressurized and recycled by a fan.

[0033] During the cooling process in step S4, the protective gas whose temperature rises enters the next powder material heat treatment unit through valve 2 on the pipeline connected to the gas outlet of the heat exchanger. This gas is used to heat the powder and recover heat.

[0034] During the heat treatment process, the pressurized reaction gas in the high-pressure reaction gas tank is used to backflush and clean the powder deposited on the bottom surface of the sintered porous filter plate by the timed opening and closing of the solenoid valve.

[0035] The reaction gas inlet valve four is kept open to maintain the powder heat treatment chamber and gas system at a positive pressure level.

[0036] The above technical solution has at least the following advantages compared with the existing technology:

[0037] The above scheme involves heat treatment of the powder to remove adsorbed moisture and impurity gases, and certain surface reaction pretreatment, which can improve the cleanliness of the powder raw materials and the quality of the gas-solid reaction products.

[0038] This invention employs a sintered porous air distribution plate in the powder heat treatment chamber of the powder heat treatment device, which significantly improves the high-temperature resistance of the air distribution plate. A sintered porous filter plate is also used in the powder heat treatment chamber to achieve powder filtration under high-temperature conditions, thereby improving the purity of the outlet gas and effectively solving the problems of dust pollution and clogging in the heat exchanger. The heat-treated powder can be discharged at high temperature, low temperature, or room temperature, adapting to the requirements of the next process. The combined use of multiple powder heat treatment units enables complete heat recovery during the powder cooling process. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the apparatus for heat treatment of powder materials according to the present invention.

[0041] The annotations in the attached figures are explained as follows:

[0042] 1-Powder heat treatment chamber; 101-Powder feed valve; 102-Upper air chamber; 103-Sintered porous filter plate; 104-Powder material; 105-Sintered porous air distribution plate; 106-Lower air chamber; 107-Electric heating device; 108-Powder discharge valve;

[0043] 2-Heat exchanger; 3-Fan; 4-Solenoid valve; 5-High-pressure reaction gas tank;

[0044] 6-Valve 1; 7-Valve 2; 8-Valve 3; 9-Valve 4; 10-Valve 5; 11-Valve 6; 12-Valve 7; 13-Fluorise. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0046] It should be noted that the terms "up", "down", "left", "right", "front", and "back" used in this invention are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0047] This invention provides an apparatus and method for heat treatment of powder materials.

[0048] The device includes N-stage series-connected powder material heat treatment units.

[0049] like Figure 1 The diagram shown is a schematic of a processing unit. The powder material heat treatment unit includes a powder heat treatment chamber 1, a heat exchanger 2, a fan 3, a high-pressure reaction gas tank 5, and a flue 13.

[0050] A powder feed pipe is connected to the upper side of the powder heat treatment chamber 1, and a powder discharge pipe is connected to the lower side of the powder heat treatment chamber 1.

[0051] The upper part of the powder heat treatment chamber 1 is provided with a sintered porous filter plate 103, and the lower part is provided with a sintered porous air distribution plate 105. When setting it, it is ensured that the sintered porous air distribution plate 105 can bear the weight of the powder material without deformation, and that the sintered porous filter plate 103 does not deform when the high-pressure reaction gas tank is backflushed.

[0052] Powder material 104 is filled between the sintered porous filter plate 103 and the sintered porous air distribution plate 105.

[0053] The top of the sintered porous filter plate 103 is an upper air chamber 102.

[0054] The lower part of the sintered porous air distribution plate 105 is a lower air chamber 106, and an electric heating device 107 is installed in the lower air chamber 106;

[0055] The gas inlet at the top of the powder heat treatment chamber is connected to the high-pressure reaction gas tank 5 via a pipeline;

[0056] The gas outlet at the top of the powder heat treatment chamber is connected to a waste gas recovery device, a heat exchanger 2, and a flue 13 via pipes.

[0057] The gas inlet at the bottom of the powder heat treatment chamber is connected to the gas outlet of the heat exchanger via a pipe.

[0058] The gas inlet of the heat exchanger is also connected to the gas outlet of the fan via a pipe, and the gas outlet of the fan is also connected to the flue via a pipe;

[0059] The blower gas inlet is connected to the reaction gas pipeline, the protective gas pipeline, and the heat exchanger gas outlet;

[0060] The gas outlet of the heat exchanger is also connected to the next powder material heat treatment unit.

[0061] In practical applications, N is not less than 1. A powder feed valve 101 is provided on the powder feed pipe, and a powder discharge valve 108 is provided on the powder discharge pipe.

[0062] The powder feed pipe is connected to the lower part of the sintered porous filter plate in the powder heat treatment chamber, and the powder discharge pipe is connected to the upper part of the sintered porous air distribution plate in the powder heat treatment chamber.

[0063] A solenoid valve 4 is installed on the pipeline connecting the gas inlet at the top of the powder heat treatment chamber to the high-pressure reaction gas tank.

[0064] A valve 7.12 is installed on the pipe connecting the gas outlet at the top of the powder heat treatment chamber to the waste gas recovery device. No valve is installed on the pipe connecting to the heat exchanger, and a valve 6.11 is installed on the pipe connecting to the flue.

[0065] A valve 10 is installed on the pipe connecting the gas outlet of the blower and the flue; a valve 9 is installed on the reaction gas pipe; a valve 8 is installed on the protective gas pipe; a valve 7 is installed on the pipe connecting the gas outlet of the heat exchanger to the next powder material heat treatment device; and a valve 6 is installed on the pipe connecting the gas outlet of the heat exchanger to the bottom gas inlet of the powder heat treatment chamber.

[0066] The application method of this device includes the following steps:

[0067] S1. Powder enters the powder heat treatment chamber 1 through the powder feed pipe, and the powder feed valve 101 is closed. The reaction gas enters the lower air chamber 106 and enters the powder material 104 through the pores of the sintered porous air distribution plate 105. In the fluidized state, the gas replaces the air in the powder material layer. The replaced gas exits the powder heat treatment chamber after passing through the sintered porous filter plate and enters the waste gas recovery device or flue.

[0068] S2. After 10-60 minutes of room temperature reaction gas replacement, turn on the electric heating device 107 and use medium temperature reaction gas at 200℃ to 300℃ to replace the moisture adsorbed by the powder material and the oxygen adsorbed on the surface of the powder particles.

[0069] S3. After purging with medium-temperature reaction gas for 1-2 hours, heat the powder to 1200℃-1450℃ with high-temperature reaction gas at 1100℃-1500℃ and maintain it for 0.2-10 hours to complete the heat treatment process.

[0070] S4. After the powder heat treatment process is completed, the electric heating device 107 is turned off, and the hot powder is discharged from the powder discharge valve 108 and enters the next process, realizing hot discharge.

[0071] or,

[0072] After the powder heat treatment process is completed, the electric heating device is turned off, and the high-temperature powder is cooled with room temperature protective gas. After cooling, the powder is discharged from the powder discharge valve 108, realizing low temperature or room temperature discharge.

[0073] In steps S2 and S3, the hot reaction gas exiting the powder heat treatment chamber through the sintered porous filter plate recovers heat through the heat exchanger 2 and is then pressurized and recycled by the fan 3.

[0074] During the cooling process in step S4, the protective gas whose temperature rises enters the next powder material heat treatment unit through valve 27 to heat the powder and recover heat.

[0075] During the heat treatment process, the pressurized reaction gas in the high-pressure reaction gas tank 5 is used to backflush and clean the powder deposited on the bottom surface of the sintered porous filter plate 12 by the timed opening and closing of the solenoid valve 4.

[0076] The reaction gas inlet valve 49 is kept open to maintain the powder heat treatment chamber 1 and the gas system at a positive pressure level.

[0077] In practical applications, the reaction rate between the heat-treated powder and the reaction gas, as well as the degree of reaction on the powder surface, can be controlled by adjusting the ratio of the reactant gas and the protective gas.

[0078] The powder heat treatment chamber 1 of the powder heat treatment device is a rectangular, cylindrical or conical container. The lower part of the container is equipped with a sintered porous air distribution plate that provides support, and the top is equipped with a sintered porous filter plate for powder filtration. The outer wall of the container consists of refractory material, heat insulation material and metal shell from the inside to the outside.

[0079] In step S1 above, if the replaced gas is environmentally friendly, it is discharged from the system through valve six 11 and flue 13; if it is not environmentally friendly, it is returned to the waste gas recovery device through valve seven 12.

[0080] The following section will explain the specific implementation process.

[0081] 1. Air exchange

[0082] After the powder is fed into the powder heat treatment chamber 1 through the powder feed valve 101, the powder feed valve 101 is closed. Room temperature reaction gas (the type of reaction gas is selected based on the properties of the powder material) enters the lower air chamber 106 through the inlet valve 49 and the fan 3, and then enters the powder material 104 through the pores of the sintered porous air distribution plate 105, gradually replacing the air in the powder layer under fluidized conditions. If the reaction gas is environmentally friendly, it is discharged from the system through the flue 13 via valve 61; if the reaction gas is not environmentally friendly, it is returned to the waste gas recovery device via valve 712.

[0083] 2. Powder purification

[0084] After 20 minutes of air replacement with room temperature reaction gas, the electric heating device 107 is turned on to replace the moisture adsorbed by the powder and the oxygen adsorbed on the surface of the powder particles with medium temperature reaction gas at 200℃ to 300℃.

[0085] 3. Powder heat treatment

[0086] After the powder is purified by medium-temperature reaction gas for 1.5 hours, valves 6 (11) and 7 (12) are closed, and the powder is heated to 1200℃-1450℃ using high-temperature reaction gas at 1100℃-1500℃, and maintained at this temperature for 5 hours. During the heat treatment process, the ratio of reaction gas to protective gas is adjusted by valves 3 (8) and 4 (9) to regulate the reaction rate between the powder particles and the reaction gas, as well as the degree of reaction on the powder surface. After the powder heat treatment process is completed, the electric heating device 107 is turned off, and the hot powder is discharged from the powder discharge valve 108 to enter the next process, achieving hot discharge. Alternatively, after the powder heat treatment process is completed, the electric heating device is turned off, and the high-temperature powder is cooled with room-temperature protective gas (generally an inert gas) to achieve low-temperature or room-temperature discharge; the cooled gas after heating enters another powder material heat treatment unit through valve 2 (7) to preheat the powder and recover residual heat.

[0087] 4. Backflushing of sintered porous filter plates

[0088] During the aforementioned air replacement, powder purification, and powder heat treatment operations, the solenoid valve opens periodically every 10 minutes, closing after 2 seconds each time. When the solenoid valve opens, the reaction gas (pressure 0.2 MPa) in the high-pressure reaction gas tank 5 impacts into the upper air chamber 102, backflushing and cleaning the powder deposited on the bottom surface of the sintered porous filter plate 103.

[0089] The following points need to be explained:

[0090] (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0091] (2) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0092] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An apparatus for heat treatment of powder materials, characterized in that, Includes N-stage series-connected powder material heat treatment units, The powder material heat treatment unit includes a powder heat treatment chamber, a heat exchanger, a fan, a high-pressure reaction gas tank, and a flue. A powder feed pipe is connected to the upper side of the powder heat treatment chamber, and a powder discharge pipe is connected to the lower side of the powder heat treatment chamber. A sintered porous filter plate is installed in the upper part of the powder heat treatment chamber, and a sintered porous air distribution plate is installed in the lower part. Powder material is filled between the sintered porous filter plate and the sintered porous air distribution plate; The top of the sintered porous filter plate is an upper air chamber. The lower part of the sintered porous air distribution plate is a lower air chamber, and an electric heating device is installed in the lower air chamber. The gas inlet at the top of the powder heat treatment chamber is connected to a high-pressure reaction gas tank via a pipeline. The gas outlet at the top of the powder heat treatment chamber is connected to a waste gas recovery device, a heat exchanger, and a flue via pipes. The gas inlet at the bottom of the powder heat treatment chamber is connected to the gas outlet of the heat exchanger via a pipe. The gas inlet of the heat exchanger is also connected to the gas outlet of the fan via a pipe, and the gas outlet of the fan is also connected to the flue via a pipe; The blower gas inlet is connected to the reaction gas pipeline, the protective gas pipeline, and the heat exchanger gas outlet; The gas outlet of the heat exchanger is also connected to the next powder material heat treatment unit. The N is not less than 1, a powder feed valve is provided on the powder feed pipe, and a powder discharge valve is provided on the powder discharge pipe; The powder feed pipe is connected to the lower part of the sintered porous filter plate in the powder heat treatment chamber, and the powder discharge pipe is connected to the upper part of the sintered porous air distribution plate in the powder heat treatment chamber.

2. The apparatus for heat treatment of powder materials according to claim 1, characterized in that, A solenoid valve is installed on the pipeline connecting the gas inlet at the top of the powder heat treatment chamber to the high-pressure reaction gas tank.

3. The apparatus for heat treatment of powder materials according to claim 1, characterized in that, A valve seven is installed on the pipe connecting the gas outlet at the top of the powder heat treatment chamber to the waste gas recovery device. No valve is installed on the pipe connecting to the heat exchanger, and a valve six is ​​installed on the pipe connecting to the flue.

4. The apparatus for heat treatment of powder materials according to claim 1, characterized in that, Valve 5 is installed on the pipe connecting the gas outlet of the blower and the flue; valve 4 is installed on the reaction gas pipe; valve 3 is installed on the protective gas pipe; valve 2 is installed on the pipe connecting the gas outlet of the heat exchanger to the next powder material heat treatment device; and valve 1 is installed on the pipe connecting the gas outlet of the heat exchanger to the gas inlet at the bottom of the powder heat treatment chamber.

5. The method of applying the apparatus for heat treatment of powder materials according to claim 1, characterized in that, The steps include the following: S1. Powder enters the powder heat treatment chamber through the powder feed pipe and the powder feed valve is closed. The reaction gas enters the lower air chamber and enters the powder material through the pores of the sintered porous air distribution plate. In the fluidized state, it replaces the air in the powder material layer. The replaced gas exits the powder heat treatment chamber after passing through the sintered porous filter plate and enters the waste gas recovery device or flue. S2. After 10-60 minutes of room temperature reaction gas replacement, turn on the electric heating device and use medium temperature reaction gas at 200℃ to 300℃ to replace the moisture adsorbed by the powder material and the oxygen adsorbed on the surface of the powder particles. S3. After 1-2 hours of medium-temperature reaction gas replacement, the powder is heated to 1200℃-1450℃ with high-temperature reaction gas at 1100℃-1500℃ and held for 0.2-10 hours to complete the heat treatment process. S4. After the powder heat treatment process is completed, the electric heating device is turned off, and the hot powder is discharged from the powder discharge valve and enters the next process to achieve hot discharge. or, After the powder heat treatment process is completed, the electric heating device is turned off, and the high-temperature powder is cooled with room temperature protective gas. After cooling, the powder is discharged from the powder discharge valve, realizing low-temperature or room-temperature discharge.

6. The method of applying the apparatus for heat treatment of powder materials according to claim 5, characterized in that, In steps S2 and S3, the hot reaction gas exiting the powder heat treatment chamber through the sintered porous filter plate recovers heat through a heat exchanger and is then pressurized and recycled by a fan.

7. The method of applying the apparatus for heat treatment of powder materials according to claim 5, characterized in that, During the cooling process in step S4, the protective gas whose temperature rises enters the next powder material heat treatment unit through valve 2 on the pipeline connected to the gas outlet of the heat exchanger. This gas is used to heat the powder and recover heat.

8. The method of applying the apparatus for heat treatment of powder materials according to claim 5, characterized in that, During the heat treatment process, the pressurized reaction gas in the high-pressure reaction gas tank is used to backflush and clean the powder deposited on the bottom surface of the sintered porous filter plate by the timed opening and closing of the solenoid valve. The reaction gas inlet valve four is kept open to maintain the powder heat treatment chamber and gas system at a positive pressure level.

Images