Why do lamp heads tend to break down after the synthesis furnace is shut down?

Please, the original poster, explain the specific situation so we can analyze it together

1. The lamp base is made of quartz, which is a poor conductor of heat； 2. What is the installation method between the lamp base and the holder? We use a graphite base, which is then wrapped and filled with asbestos rope ； 3. Is there any internal leakage in the synthesis furnace? Water entering it can be fatal to the high-temperature lamp heads. :lol

It depends on what kind of furnace it is; if it’s an iron furnace, then the lamp holder should also be made of iron. When the furnace is damaged, combustion causes oxidation of the iron, and the residual hydrogen chloride gas after the furnace is shut down can also corrode the lamp holder. The oxidation reaction during combustion is inevitable; the residual hydrogen chloride gas must be removed promptly, which can be achieved by flushing with nitrogen. The graphite furnace lamp holder should be made of quartz, as it is a poor conductor of heat. When shutting down the furnace, it should be done gradually, not too quickly, to avoid rapid changes in temperature. The ratio of chlorine to hydrogen gas must be appropriate when there is combustion. Avoid film bursting. Chlorine and hydrogen must be pure; reducing the presence of impurities can extend the lifespan of the lamp base. After shutting down the furnace, nitrogen should be purged promptly to reduce the corrosion of hydrogen chloride on the lamp head.

　　After parking, the furnace is usually kept under vacuum to remove any remaining hydrogen from within it, thereby ensuring safety. In this case, each unit has its own regulations; using air replacement is sufficient. 　　Did they say nitrogen filling upstairs? Is it 79% nitrogen? Just joking: lol, 79% nitrogen is air. In the spirit of conservation, let’s use air instead. :victory:

We use a three-in-one synthesis furnace; every time it stops operating, the quartz lamp heads get damaged. We can’t figure out the reason. Are there any measures that can be taken to fix this?

Personally, I think there are several possible explanations: 1. If the lamp holder is located at the top, and the shutdown procedure is incorrect, the vacuum system stops first, which causes the flame to rise and heat the lamp holder. Uneven heating can lead to the lamp holder cracking. 2. Water getting onto the lamp base is, in the vast majority of cases, caused by water falling on the lamp base. There are many reasons for water formation; one can check the flowchart to identify the cause – it could be water absorption, cooling water, or an excessive amount of water in the hydrogen. 3. There are problems with the quartz glass; its quality is poor. This situation has also occurred many times. It would also be good to clarify whether the three-in-one units produced by your factory use upper air intake (with the lamp head at the top and the flame going downward) or lower air intake (with the lamp head at the bottom and the flame going upward)

I recommend going to Jin Chemical*; their three-in-one furnaces operate very smoothly, and the light bulbs used in them have a long lifespan. You should check the three-in-one furnace carefully to see if there’s a problem with it; I’ve never heard of a situation where the light bulbs break down just because the furnace stops working.

Reason: 1. High water content in hydrogen can cause explosions during the production process. 2. Hydrogen contains a high level of alkali, while chlorine contains acid; these substances accumulate at the lamp base, causing uneven heating of that area. 3. The distribution of absorbed water is uneven, and water ends up reaching the lamp base. 4. The quality of the lamp base – those made from domestically produced materials contain less quartz –; such lamp bases are cheaper but have a shorter lifespan. I would like to ask which factory produces the Jinhua lamp bases. Does anyone know? The quality of the lamp bases produced by our factory is poor, so they need to be replaced whenever the furnace stops operating.

The reasons for a faulty lamp base are as follows; please refer to these: 1. Quartz-based lamp bases are poor heat conductors, and large temperature differences are the main cause of them bursting； After shutting down the furnace, nitrogen filling can be used for protection, which yields good results – it protects the synthesis furnace system while also reducing the likelihood of lamp head explosions ； 2. The quality of the lamp base should come from reputable manufacturers; quartz lamp bases produced abroad can withstand being poured with cold water while in use without exploding, which really surprised me. Of course, their price is more than 10 times higher than those of domestic ones ；

Jinhua’s light bulbs are produced in Liaoyang, and those from Nantong Global Graphite Factory are also good