CN206240095U - A kind of device for preparing ultrathin composite powder - Google Patents

Abstract

The utility model discloses a device for preparing superfine composite powder, which belongs to the fields of powder metallurgy and 3D printing. The utility model describes a device for preparing composite powder by spray pyrolysis using microwave heating as a heat source, which is characterized in that the atomized precursor salt solution is sprayed and atomized, and the reaction chamber is simultaneously Microwave heating, the atomized droplets are dried, chemically reacted (thermal decomposition oxidation and thermal decomposition reduction reaction) and sintered in a very short settling time and a suitable high temperature environment to generate simple powder or composite powder. The powder prepared by the utility model has the characteristics of controllable shape, concentrated particle size distribution, high purity, etc. The device has the characteristics of simple and easy operation, easy automation, energy saving, environmental protection, green and high efficiency.

Description

A device for preparing ultrafine composite powder

technical field

The utility model relates to a device for preparing superfine composite powder, in particular to a device for industrially and continuously producing superfine composite powder with microwave-assisted spray pyrolysis.

Background technique

The preparation of composite powder by spray pyrolysis is to prepare the precursor solution according to the stoichiometric ratio required for the preparation of composite powder by various metal salts. After atomization, the carrier gas is brought into the high-temperature reaction chamber. Medium and fast movement, instantaneously complete a series of physical and chemical processes such as solvent evaporation, solute precipitation to form solid particles, particle drying, particle thermal decomposition, and sintering.

Spray pyrolysis has many advantages. ①The raw materials are mixed in the solution state, which can ensure the uniform distribution of components, and the process is simple, the loss of component components is small, and the stoichiometric ratio can be precisely controlled, especially suitable for the preparation of multi-component composite powders; ② Micropowder is dried from liquid droplets suspended in the air. The particles are generally spherical in shape and less agglomerated. There is no need for subsequent washing and grinding, which ensures the high purity, high activity, fine grains and uniformity of particle size of the product; ③ Various ultrafine particles with different shapes and properties are prepared through different process conditions. The nanoparticles produced by this method have low apparent density, large specific surface area, and good powder sintering performance; ④ The whole process takes only a few seconds It is completed quickly, so there is no time for component segregation of droplets during the reaction process, which further ensures the uniformity of component distribution; ⑤The process is simple, and the final powder can be obtained in one step, without filtering, washing, drying, and crushing processes, and the operation is simple and convenient , The production process is continuous, the production capacity is large, the production efficiency is high, and it is safe and pollution-free, which is very conducive to large-scale industrial production and green economic development.

Microwave heating has the characteristics of fast heating speed, small heat loss, and convenient operation. It can not only shorten the process time, increase productivity, reduce costs, but also improve product quality. Compared with traditional heating methods, microwave heating has the following characteristics: ①Uniform heating and fast speed: the general heating method relies on heating the surrounding environment to heat the surface of the object first by heat radiation or hot air convection, and then The interior of an object is conducted by heat conduction. This method has low efficiency and long heating time. Microwaves are generated inside the object to be heated, and the heat source comes from the inside of the object. The heating is uniform and will not cause the phenomenon of "cooked on the outside and not cooked on the inside", which is conducive to improving product quality. Heating time and high heating efficiency are beneficial to increase product output; ②The inertia of microwave heating is very small, which can realize rapid control of temperature rise and fall, which is conducive to continuous production and automatic control. Conventional heating methods, such as steam heating, electric heating, and infrared heating Wait, it takes a certain amount of time to reach a certain temperature, and it will take a long time for the temperature to drop when a failure occurs or heating is stopped, while microwave heating can quickly adjust the microwave power to the required value within a few seconds. Heating to an appropriate temperature is convenient for automatic and continuous production, timely control and sensitive response; ③Selective heating: the heat generated by microwave heating is closely related to the loss of the heated object, and the dielectric constant of various media is from 0.0001 to 0.5, so different objects, or different components in objects, have great differences in the ability to absorb microwaves; ④ Non-thermal effects: Compared with traditional heating results under the same thermodynamic conditions, microwave heating has significant advantages in each These phenomena include the increase of the atomic diffusion rate of the substance, the activation and sintering of the powder material, the promotion of the densification of the compact, the promotion of the grain growth, and the increase of the chemical reaction rate, as well as the resulting excellent properties and special microscopic properties. Structure, etc.; ⑤Strong penetration ability of microwave heating: penetration ability is the ability of electromagnetic waves to penetrate into the medium. When electromagnetic waves enter the medium from the surface and propagate inside, the energy it carries The heat decays exponentially with the distance into the surface of the medium. The penetration depth and wavelength of electromagnetic waves are of the same order of magnitude. Except for larger objects, it is generally possible to heat both the surface and the inside. However, the wavelength of far-infrared heating is very long, and the penetration ability is poor during heating. Under the irradiation of far-infrared rays, only a thin layer of the object generates heat, and the heat mainly depends on conduction to the inside, which not only takes a long time to heat, but also easily causes uneven heating. . According to the comparison, the penetration ability of microwave heating is much stronger than that of far-infrared heating; ⑥Clean and hygienic, no pollution: general industrial heating equipment is relatively large, occupies a large area, and the ambient temperature is relatively high, and the working conditions of the operators are poor and the intensity is high. . The microwave heating occupies a small area, avoids the high temperature of the environment, and greatly improves the working conditions of the workers.

With the rapid development of 3D printing technology, more and more urgent requirements are put forward for the upgrading of powder metallurgy pulverization technology. The preparation of composite powder is an important material basis for 3D printing technology, and good sphericity, high purity and uniform distribution of components are important directions for the development of powder preparation. The utility model combines the complementary advantages of spray pyrolysis and microwave heating, and the synergistic advantages of the two provide technical support and process basis for the preparation of ultrafine composite powder.

Contents of the invention

The purpose of this utility model is to provide a device for preparing ultrafine composite powder, which includes a stocker 1, a gas generator 2, a spray device 3, a high temperature reaction chamber 4, a microwave heating chamber 5, a microwave generator Device 6, microwave auxiliary heating device 7, fluid delivery pump 8, dust collection device 9, powder collection device 10, tail gas treatment device 11, purification device 12, stocker 1 is connected to spray device 3, and spray device 3 is located in the high temperature reaction The top of the cavity 4; the gas generator 2 communicates with the top of the high-temperature reaction cavity 4, the high-temperature reaction cavity 4 is provided with a microwave heating cavity 5, and the microwave heating cavity 5 is provided with a microwave generating device 6 for microwave heating. A microwave auxiliary heating device 7 is provided inside the chamber 5; the bottom of the high temperature reaction chamber 4 communicates with the dust collection device 9 through a fluid delivery pump 8, and a powder collection device 10 is provided under the dust collection device 9, and the dust collection device 9 passes through The pump communicates with the tail gas treatment device 11 , and the tail gas treatment device 11 communicates with the purification device 12 .

Preferably, the device of the present invention is provided with more than two dust collecting devices 9, and the multiple dust collecting devices 9 are connected in sequence.

Preferably, the spray device 3 of the present invention is an ultrasonic atomizer or a mechanical nozzle, and the particle size of sprayed droplets is determined by the frequency and power of the ultrasonic atomizer, as well as the type and design parameters of the mechanical nozzle.

Preferably, the high-temperature reaction chamber of the present invention is a tube furnace, a gas fluidized bed or a rotary kiln.

The microwave heating chamber 5 described in the utility model is a metal closed chamber, preferably a stainless steel metal chamber, or other metal chambers.

Preferably, the microwave heating chamber 5 and the high-temperature reaction chamber 4 of the present invention are provided with wave-transparent insulation materials, such as alumina fiber, mullite, corundum, and the like.

Preferably, the dust collection device described in the utility model is bag dust collection, electrostatic dust collection, magnetic dust collection or cyclone dust collection.

The microwave generating device of the utility model is composed of a magnetron for generating microwaves and a power supply system, and the preferred heating frequency is 2450MHz, 915MHz and the like.

The microwave auxiliary heating device of the utility model is composed of wave-absorbing materials, preferably silicon carbide, aluminum borosilicate, and ferrite.

Beneficial effects of the utility model: the utility model combines the complementary advantages of spray pyrolysis and microwave heating, and the rapid drying, decomposition and sintering of spray combined with the characteristics of rapid heating, uniform heating and non-thermal effect of microwave are beneficial to the preparation of ultrafine, Nanocrystalline, high sphericity, high purity, uniform component distribution, narrow particle size distribution range, good sinterability, safety and reliability, and can be prepared for industrial mass production.

Description of drawings

Fig. 1 is the structural representation of the utility model.

In the figure: 1-stocker; 2-gas generator; 3-spray device; 4-high temperature reaction chamber; 5-microwave heating chamber; 6-microwave generating device; 7-microwave auxiliary heating device; 8-fluid Delivery pump; 9-dust collection device; 10-powder collection device; 11-tail gas treatment device; 12-purification device.

detailed description

The utility model will be described in further detail below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the utility model is not limited to the content described.

Example 1

The device for preparing ultrafine composite powder described in this embodiment includes a stocker 1, a gas generator 2, a spray device 3, a high-temperature reaction chamber 4, a microwave heating chamber 5, a microwave generating device 6, and a microwave auxiliary heating device 7 , a fluid delivery pump 8, a dust collection device 9, a powder collection device 10, an exhaust gas treatment device 11, a purification device 12, the stocker 1 is connected to the spray device 3, and the spray device 3 is located at the top of the high-temperature reaction chamber 4; gas generation The device 2 communicates with the top of the high-temperature reaction chamber 4, the high-temperature reaction chamber 4 is provided with a microwave heating chamber 5, the microwave heating chamber 5 is provided with a microwave generating device 6, and the inside of the microwave heating chamber 5 is provided with a microwave Auxiliary heating device 7; the bottom of the high-temperature reaction chamber 4 communicates with the dust collection device 9 through a fluid delivery pump 8, and a powder collection device 10 is provided below the dust collection device 9, and the dust collection device 9 communicates with the tail gas treatment device 11 through a pump, The tail gas treatment device 11 communicates with the purification device 12 .

Example 2

The device for preparing ultrafine composite powder described in this embodiment includes a stocker 1, a gas generator 2, a spray device 3, a high-temperature reaction chamber 4, a microwave heating chamber 5, a microwave generating device 6, and a microwave auxiliary heating device 7 , a fluid delivery pump 8, a dust collection device 9, a powder collection device 10, an exhaust gas treatment device 11, a purification device 12, the stocker 1 is connected to the spray device 3, and the spray device 3 is located at the top of the high-temperature reaction chamber 4; gas generation The device 2 communicates with the top of the high-temperature reaction chamber 4, the high-temperature reaction chamber 4 is provided with a microwave heating chamber 5, the microwave heating chamber 5 is provided with a microwave generating device 6, and the inside of the microwave heating chamber 5 is provided with a microwave Auxiliary heating device 7; the bottom of the high-temperature reaction chamber 4 communicates with the dust collection device 9 through the fluid delivery pump 8, and there are 3 dust collection devices 9, and the 3 dust collection devices 9 are connected in sequence, and the powder collection device 10 is provided below , the last dust collector 9 communicates with the exhaust gas treatment device 11 through a pump, and the exhaust gas treatment device 11 communicates with the purification device 12 .

In this embodiment, the spray device 3 is an ultrasonic atomizer, the high-temperature reaction chamber is a tube furnace, the microwave heating chamber 5 is a stainless steel metal chamber, and alumina is arranged between the microwave heating chamber 5 and the high-temperature reaction chamber 4 Fiber, the dust collection device is bag dust collection.

The use process of the device described in this embodiment: place the pre-prepared precursor solution in the storage tank 1, then select the generator 2 suitable for the atmosphere according to the state of the obtained powder, and turn on the microwave generator 6 The microwave cavity is heated, and the temperature and temperature distribution in the cavity are controlled by adjusting the microwave output power and the distribution of the auxiliary heating device 7, and then the material and gas switches are turned on, and the precursor solution is sprayed through the atomization device 3, and the droplets The obtained powder product is transported to the dust collection device 9 and the powder collection device 10 through the fluid conveying device 8 for collection, and the excess gas is processed through the tail gas treatment device 11 and the purification device 12 .

Claims (7)

1. a kind of device for preparing ultrathin composite powder, it is characterised in that：Described device includes accumulator（1）, gas generator （2）, sprayer unit（3）, pyroreaction cavity（4）, heating using microwave cavity（5）, microwave generating apparatus（6）, Microwave-assisted firing Device（7）, fluid delivery pump（8）, dust arrester installation（9）, powder collection device（10）, exhaust gas processing device（11）, purifier （12）, accumulator（1）With sprayer unit（3）Connection, sprayer unit（3）Positioned at pyroreaction cavity（4）Top；Gas occurs Device（2）With pyroreaction cavity（4）Top connection, pyroreaction cavity（4）Outside be provided with heating using microwave cavity（5）, it is micro- Wave heating cavity（5）It is provided with microwave generating apparatus（6）, heating using microwave cavity（5）Inside be provided with Microwave-assisted firing device （7）；Pyroreaction cavity（4）Bottom passes through fluid delivery pump（8）With dust arrester installation（9）Connection, dust arrester installation（9）Below set There is powder collection device（10）, dust arrester installation（9）By pump and exhaust gas processing device（11）Connection, exhaust gas processing device（11）With Purifier（12）Connection.

2. the device of ultrathin composite powder is prepared according to claim 1, it is characterised in that：It is provided with two or more dust arrester installation （9）, multiple dust arrester installations（9）Between be sequentially communicated.

3. the device of ultrathin composite powder is prepared according to claim 1, it is characterised in that：The sprayer unit（3）It is super Sound atomizer or pressure jet apparatus.

4. the device of ultrathin composite powder is prepared according to claim 1, it is characterised in that：The pyroreaction cavity is pipe Formula stove, gas fluidized bed or kiln.

5. the device of ultrathin composite powder is prepared according to claim 1, it is characterised in that：Heating using microwave cavity（5）It is gold Category closed cavity.

6. the device of ultrathin composite powder is prepared according to claim 1, it is characterised in that：Heating using microwave cavity（5）With height Warm reaction cavity（4）Between be provided with wave transparent insulation material.

7. the device of ultrathin composite powder is prepared according to claim 1, it is characterised in that：The dust arrester installation is received for cloth bag Dirt, electrostatic dust collection, magnetic force gather dust or cyclone dust collection.