Special application of inhibiting the bad effect of zinc vapor
When it comes to how the bad effect of zinc vapor is suppressed, it is easy to think first of all: what is the bad effect of zinc vapor? When it comes to the bad effect of steam, it is easy to think of it in the first place"Should the bad effect of zinc vapor be emphasized in hot aluminized zinc silicon?
We know that any liquid substance will evaporate at a temperature range below the boiling point above the melting point, but the amount of evaporation varies with the temperature. Water H0, for example, 0 ℃ under ordinary conditions of its melting point, boiling point is 100 ℃, under the above 0 ℃ 100 ℃ temperature range, the greater the higher evaporation temperature. Zinc and zinc melting point is 419 ℃, boiling point is 907 ℃, under the above 419 ℃ 907 ℃ temperature range, the greater the liquid zinc the higher evaporation temperature. Ordinary hot dip galvanized zinc liquid working temperature is 460 ℃ or so, only about 41 ℃ higher than the melting point and if proportionally controlled, the equivalent of 8.4 ℃. 8.4 ℃ water evaporation is very small, understandable, 460 ℃ of zinc liquid evaporation is small. Because the amount of vaporized zinc vapor is small, the adverse effect on the production of hot galvanizing is not obvious, so the bad effect of zinc vapor is seldom discussed in hot galvanizing.Hot aluminum zinc silicon is different. Due to the high melting point zinc aluminum silicon alloy, aluminium zinc silicon alloy liquid working temperature is 610 ℃ or so. 610 ℃ 610 ℃ higher than the melting point of zinc, for zinc alloy liquid of content 43%, to 610 ℃ is equivalent to water "in 39. 1 ℃. 39. 1 ℃ water evaporation is bigger, can understand, 610 ℃ solution of zinc evaporation is larger. Due to the large amount of zinc vapor, the production of hot-coated aluminum zinc zinc silicon will have a significant adverse effect, so we must take seriously the problem of zinc vapor. Of course, no matter water or liquid zinc, the relationship between evaporation and temperature is not a simple straight line, but a complex curve relationship, except that there is a general trend that evaporation increases with temperature.
What's wrong with zinc vapor? Like the hot dip aluminum zinc silicon, nasal groove from the zinc plating solution surface evaporation steam upward movement, the trunk tank room, hot roller, cooling segment (if not balanced section), encounter cold can produce sublimation, condenses into solid zinc powder, stick to the roll surface, air cooling air outlet surface and roof, furnace wall surface, whenever boiler stop, open the lid of the stove, air into the furnace, zinc powder oxidizing reaction, into Zno Zno, this is known as zinc ash. Zinc dust accumulated over time, more and more. In this way, loose zinc-ash accumulation particles will fall on the surface of the furnace roll and then adhere to the surface of the steel belt, resulting in surface defects such as leakage after plating. Zinc ash accumulation particles surrounded by roller compaction GeWo will bring pressure on steel. That's the downside of zinc vapor