HTF from currently marketed, the heat at 300 ℃ 10 childhood, Taiyuan heat oil, thermal oil and some black soot wafting in there, this is a typical problem formulation or base oil is also a problem; some 300 ℃ for 40 hours, at the bottom there is a small amount of oil soot settle down; there are 60 hours of oil heating, heat oil producers oxide interface is very clear; there is oil heating at 300 ℃ 100 hours , oil has shown a black oxide interface, there is a lot of oil in bitumen-like precipitate; there was heated at 300 ℃ 100 hours, and the entire oil have become dark reddish brown oil is also black carbon particles precipitate, glass dirty wall was dark; there after conducting oil heating in the lower container forming dark contaminants, some HTF and the formation of dark contaminants at the top of the container. The other method of determination of thermal stability of a thermal oil GB / T 23800 is sealed under nitrogen, heat oil suppliers, heating oil 720h or 1000h, the deterioration rate is calculated to be less than or equal to 10% of the eligible. This nitrogen seal oil furnace system is good, but for the vast majority of China's oil furnace is no nitrogen seal system, are in direct contact with the air system, and this is a big problem, pass Hot oil production, under a nitrogen seal performance is good, not necessarily in the non-nitrogen seal performance or. About the extensive use of temperature encountered only 200 ℃, only use 2--3 years to be scrapped, it is indicative of the problem. Heat oil picture | Fengqiu County Taihang Chemical (Online) | Kunming heat transfer oil supplied by Fengqiu County Taihang Chemical Co., Ltd. Fengqiu County Taihang Chemical Co., Ltd (www.hndaoreyou.com) Henan Xinxiang, fuel oil leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Fengqiu County Taihang Chemical Co., Ltd. leadership with the staff warmly welcome all inquiries negotiations to create Fengqiu County Taihang Chemical Co., a better future.