An fire broke out due to heat transfer oil insulation failure; please provide an explanation! !
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Our company uses 80mm glass insulation wool for insulating the heat transfer oil pipelines, plastic sheeting as a moisture barrier, and galvanized iron sheeting as a protective layer. Some time ago, a fire broke out in the heat transfer oil pipes. The workshop suspected that plastic sheeting was the cause of the fire, but after doing some research on Baidu, I found that the ignition point of plastic sheeting is around 350 degrees, while the temperature of our heat transfer oil pipes is approximately 250 degrees – far below the temperature required for ignition. Therefore, we suspect that it was most likely a leak in the heat transfer oil pipes that caused the fire. I would like to ask now: is it possible for plastic sheeting to catch fire? ?
Is plastic sheeting truly flame-retardant plastic sheeting?
Check the pipes to determine if there are any leaks. Inspect the heat transfer oil to determine its current flash point and auto-ignition temperature, and check whether they reach 250°C.
Confirm the location of the fire source to see if it is in areas prone to leakage such as valves or flanges. Additionally, check the type of heat transfer oil and its duration of use; generally, mineral-based heat transfer oils, especially alkane-based ones, will slowly decompose at high temperatures, producing coke and light components, which lowers their flash point. In the event of a leak, these oils may catch fire.
The ignition point should also be checked to see if it is at the electric heating element; it’s possible that arcing from the electric heating element caused the fire
A fire broke out due to a leak in the heat transfer oil pipe; the leaked fluid is highly flammable. Make sure to take proper safety measures during testing.
Based on my past experience, it’s definitely a leak of heat transfer oil. The heat transfer oil enters the insulation layer, where it gradually vaporizes; yet it is enclosed by the outer metal sheet, preventing it from escaping. When its concentration reaches a certain level, it catches fire on its own under high temperatures. But it only emits black smoke; due to a lack of oxygen, it catches fire as soon as it is exposed.
At high temperatures, components such as flanges and valves are prone to leakage; with a flash point of less than 200 degrees, they may catch fire in the event of a leak.
What should be done in the event of a heat transfer oil leak and black smoke?
If smoke is coming from the insulation layer inside the tank, which is covered with iron sheets on the outside, a hole can be made at the appropriate position on the tank’s head, and fire extinguishing water can be poured in through that hole. It is not possible to simply open the iron sheets, as doing so would cause the fire to spread. If it is a pipeline, once the fire extinguisher and fire-fighting water are ready, open them immediately to put out the fire.