A vacuum drying device for powder metallurgy

Abstract

The invention discloses a vacuum drying device for powder metallurgy. The vacuum drying device comprises a cylinder and further comprises a top cover, wherein the top cover is used for condensing steam as well as draining and exhausting steam condensate; the cylinder and the top cover are connected in a sealing manner so as to form a closed cavity; the top cover comprises a top cover inner wall, atop cover outer wall and a cooling medium circulation channel; the cooling medium circulation channel is positioned on an interlayer between the top cover inner wall and the top cover outer wall; thetop cover inner wall takes the shape of a cone or a sphere of which the middle protrudes upward; a cooling medium inlet and a cooling medium outlet are formed on the top cover outer wall and both communicate with the cooling medium circulation channel; a condensate collecting tank used for collecting the steam condensate is arranged below the edge of the top cover inner wall; a pipeline used forexhausting the steam condensate in the condensate collecting tank is connected onto the condensate collecting tank; and a recycling barrel is connected with the output end of the pipeline. The vacuumdrying device disclosed by the invention has the advantages that the drying efficiency is high, the liquid residue is low, the rapid batched drying process can be achieved, and the purity and the quality of powder obtained from the drying process are high.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy, in particular to a vacuum drying device used for coating and modifying the surface of powder in powder metallurgy. Background technique [0002] Powder metallurgy is an important part of modern industrial development, especially in many special metals, ceramic materials and parts manufacturing industries, powder metallurgy has an irreplaceable position. In powder metallurgy technology, in order to improve the performance of metal powder, it is necessary to carry out flexible coating modification on the surface of the powder. After modification, it is necessary to evaporate the liquid in the powder suspension to obtain a surface-modified high-purity solid powder. In order to obtain a powder with low oxygen content, uniform particle size, and good flexible coating effect of organic matter, the drying rate and the uniformity of suspension distribution during drying are two extremely import...

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Problems solved by technology

In powder metallurgy technology, in order to improve the performance of metal powder, it is necessary to carry out flexible coating modification on the surface of the powder. After modification, it is necessary to evaporate the liquid in the powder suspension to obtain a surface-modified high-purity solid powder. In order to obtain a powder with low oxygen content, uniform particle size, and good flexible coating effect of organic matter, the drying rate and the uniformity of suspension distribution during drying are two extremely important factors. If the drying rate is slow and the drying time is too long, it is easy to cause The decomposition, coking and embrittlement of the flexible organic forming agent will also lead to the oxidation of the powder. If the suspension is unevenly distributed during drying, it will not be possible to obtain a powder coated with organic matter, which will seriously affect the effect of powder modification.

[0003] The existing vacuum drying equipment for powder metallurgy adopts electric heating mechanism for heating, and the solid-liquid mixture is heated unevenly. Although the evaporation rate of the liquid is fast, the rate of gas extraction and condensation is slow, and the overall drying rate is limited. As a result, the drying time is too long, the flexible organic forming agent is decomposed, coked and brittle, and the flexible coating cannot be obtained. In addition, the existing vacuum drying equipment mainly exhausts the gas through vacuuming, which is not only inefficient, but also when the steam encounters Condensation on the wall of the top cover of the container will also drip back into the suspension. When the condensate drips back, it will also cause local oscillation of the suspension, resulting in uneven distribution of the suspension, resulting in the inability to obtain a uniform coating layer. Therefore, the existing vacuum The drying device cannot meet the efficient, fast and clean drying requirements required for powder surface modification in the powder metallurgy industry, and cannot realize the modification process of uniform flexible organic coating on the powder surface, which restricts the further development of powder metallurgy technology

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