Drying process for preventing dried iron core from rusting

Abstract

The invention discloses a drying process for preventing a dried iron core from rusting. The drying process comprises the four main steps as follows: a pre-dewatering stage, a preheating stage, a pressure changing stage and a final drying step, wherein the pre-dewatering stage comprises gradually heating air in a drying furnace until the temperature is 50 DEG C; the preheating stage comprises performing vacuum pumping until the pressure in the drying furnace as low as 40000 pa, then mixing air outside a tank until the pressure in the drying furnace returns to 80000 pa, preheating, repeating in this way: performing vacuum pumping, mixing air and preheating until the temperature of the iron core reaches 70 DEG C; the pressure changing stage comprises performing vacuum pumping for a period of time, then keeping the pressure for a period of time, repeating in the way until the pressure in the drying furnace is as low as 500 pa and the temperature of the iron core reaches 75 DEG C; and the final drying step comprises continuously performing vacuum pumping until the pressure in the tank is as low as 100 pa. The drying process has the beneficial effects that the drying process is divided into four stages, water vapor in the drying furnace during the drying process is guaranteed to be timely discharged and the oxygen content is reduced, so that the rusting of the iron core can be effectively prevented.

Description

technical field [0001] The invention relates to the technical field of transformers, in particular to a drying process for preventing iron cores from rusting after drying. Background technique [0002] The rust phenomenon of transformer iron core after drying is manifested as: [0003] Some transformer iron cores are not rusted before entering the furnace, and some are already rusted, but after drying, the rust is generally more serious; [0004] Due to the uneven heating of the iron core, the middle temperature of the iron core is not as high as the surrounding temperature when the iron core is heated, and the signs of rust spread from the surface to the surroundings, and there is almost no rust on the edge; [0005] Due to the uneven temperature in the drying furnace, the temperature of the lower layer is lower than that of the upper layer, and the evaporated water runs down, resulting in a higher concentration of water vapor in the lower layer than in the upper layer, an...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a drying process for preventing the iron core from rusting after drying, which mainly solves the problems of water vapor saturation and too much oxygen in the drying process, so as to achieve the purpose

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