Removal of vacuum aluminum brazing furnace oil need to pay attention to the problem

Removal of vacuum aluminum brazing furnace oil need to pay attention to the problem

1, to 400 degrees Celsius temperature quickly, in order to reduce the diffusion brazing junction silicon, is helpful to ensure the quality of joints. As this is aluminum brazing process requirements, must do it.
2, then take a slow long natural cooling, this step is to cleanse sandstones from fouling. At this time due to the furnace with nitrogen gas, waste heat by the cycle of nitrogen} L conduction, radiation to heat was less than the adsorption with the cold components of oil pollution. The temperature of these artifacts usually only tens of degrees, in the process can increase to 200 degrees Celsius, so as to achieve its evaporation table and pollution of the day.
3, the next coarse vacuum, one party but would have vaporized oil steam out of furnace chamber, prevent again by adsorption after cooling, the other party and, in the crude oil evaporation under vacuum environment will be more thorough. Diffusion pump no need to open, because when pressure drop to 10 pa, more than 99.99% in furnace gas has been pulled out.
4, closed cooling water of furnace wall, furnace door is to reduce heat loss, is more advantageous to raise the temperature of furnace wall. However, because the diffusion pump need cooling of equipment, can't stop water cycle system.
5, and other issues
Through such processing, baffle plate and oil base on some of the heat capacity of the smaller components can be cleared away. Wall due to the heat capacity, although closed cooling water in advance, but still kept cooling water increase the heat capacity of National People's Congress, the temperature is still rising gao, clean from the effect of oil pollution is the worst. So, in the final need to j ping work cleaning furnace wall. Because the oil is accumulated for a long time, the oil will stick with dust, is can't use this method to remove dust, oil pollution has been removed, the remaining dust adhesion is not strong, can use a vacuum cleaner to clean up, or use the clean compressed air to blow away. Can't clean the furnace wall and the last to do that, and heating evaporation, and there will be some oil vapor by adsorption. When removing dust will be, ash, _ stick. So the wall should be on the final wash clean.