Internal mixing type reactor for supercritical hydrothermal synthesis of nano-powder

Abstract

The invention discloses an internal mixing type reactor for supercritical hydrothermal synthesis of nano-powder. The reactor comprises a reaction shell with a shunting top cover and a bottom cover, wherein a reaction threaded channel is formed between the inner wall of the reaction shell and a threaded sleeve; an external thread base body is embedded in the thread sleeve to form a heat preservation water thread channel; a mixing base body is arranged at the top in the reaction shell; a supercritical water inlet channel, a material inlet channel, a heat preservation water inlet channel, a mixing straight channel and a first connecting channel are arranged in the mixing base body. A dispersing cone is arranged below the mixing base body, and a conical mixing channel is formed between the dispersing cone and the mixing base body. Outlets of the supercritical water inlet channel and the material inlet channel are converged in the mixing straight channel; the outlet of the mixing straight channel is communicated with the conical top of the conical mixing channel; and the bottom of the conical mixing channel is communicated with the top of the reaction threaded channel through the firstconnecting channel. According to the invention, the flow velocity and turbulence degree of fluid can be increased, the stability and economy of the system are improved, efficient mixing and agglomeration prevention are realized, and the industrialization process of the SCHS technology is accelerated.

Description

technical field [0001] The invention relates to a device used in technical fields such as energy, chemical industry, and synthetic materials, which can efficiently mix and improve efficiency, and particularly relates to an internal mixing type supercritical hydrothermal synthesis nanometer powder reactor. Background technique [0002] Nanotechnology is the most promising cutting-edge advanced technology in the 21st century. It has unique electrical, thermal, magnetic, optical and mechanical properties. The application of nanomaterials has triggered a revolutionary technological breakthrough in the field and has extremely bright application prospects, and the preparation of nanomaterials is the foundation and core of nanotechnology. [0003] Supercritical hydrothermal synthesis (SCHS) refers to that in a supercritical water environment (T>374.15°C, P>22.12MPa), due to the extremely low solubility of metal salts in supercritical water, rapid hydrolysis and dehydration re...

AI Technical Summary

Problems solved by technology

[0005] At present, most of the reactors used in continuous supercritical hydrothermal synthesis are tubular reactors combined with three-way mixers or countercurrent mixing reactors, but their technical problems include: (1) supercritical preheating water will inevitably The temperature is lowered by the heat absorption of the reaction fluid in the tube, the temperature cannot be maintained, and it may not be effectively injected into the low-temperature solution

(2) The reactor and the inlet are prone to particle aggregation and agglomeration, and the process pipeline will become more and more narrow and lead to final blockage, which will easily lead to valve failure and severe wear and corrosion of the components in the valve; (3) The reaction time cannot be precisely controlled , the reaction time is too long, resulting in agglomeration of nanoparticles during the growth process, producing products with larger particle sizes and reducing product quality

(4) The mixing effect of the three-way mixer is not ideal due to the low flow rate during the mixing process, while the countercurrent mixer is in the mixing process, the primary particles will be heated by the supercritical preheated water in the inner tube in the annular flow channel and easily Stagnation at right angles to exit, prone to uncontrolled thermal growth

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