What material should be used for the temperature probe sleeve when measuring the temperature of sodium hexametaphosphate exhaust gases?
Thread Content
I’ve tried 316L, Hastelloy C, and ceramic protective sleeves – all of them burned out after just a few days. The picture shows Hastelloy C, with a emerald green surface
I’ve never even heard of it. I’ll look up some information – what is it?
Here, we use thermocouples that have been treated for high-temperature resistance in the high-temperature areas of the furnaces in our oil refining plants
Thermocouples are used; the main issue is that the protective sleeve can easily get burned out. Inside the furnace, there is sodium hexametaphosphate in a molten state, which is produced by the reaction of phosphoric acid and liquid alkali. The exhaust gases contain corrosive substances, and the temperature measurement range is 600–700℃
If only high temperature resistance is required, ceramic tubes will suffice; but if both high temperature resistance and corrosion resistance are needed,
Why does the original poster say one thing but leave half unsaid? Corrosive gases, often in the form of fumes; what exactly are these fumes? Please clarify, OP. Happy New Year! For goodness’ sake, under no circumstances tell my brother – the chemical plant doesn’t even know the composition of basic substances! Otherwise, they’ll turn your factory manager, chairman, chief engineer, and everyone else into dog meat to eat. Damn it. 2018 is going to be a good year. {:3_51:}
How do ceramics get damaged? Damage from thermal expansion and contraction? Corrosion?
Can’t all ceramics resist corrosion? ?
It expands when heated and contracts when cooled; there is a process of temperature increase and decrease. Corrosion must also have some impact, as the ceramic protective sleeve has cracked and is covered with material
High temperature and corrosion should both be present, with a process of heating and cooling. It was finished in just a week