Excellent Fire Performance Of Stainless Steel—Heat Conduction Test Of Components

Observing the actually installed ladder frame, it is found that although the cable ladder frame is protected by fire, the supporting legs are not insulated and can conduct heat. The test was carried out on aluminum and stainless steel ladder frames covered with 100 mm ceramic fiber insulation. The ladder frames were supported by supporting legs without thermal insulation. Each ladder frame is equipped with a stainless steel leg and a galvanized steel leg. The aluminum support leg was not tested because it was impossible to fix it to a ladder frame with insulation. There are 12 cables on each ladder frame, which are divided into two groups and connected to both sides of the ladder frame. The ladder frame also bears a certain load to simulate other cables. Three cables on each side are connected to a cable tester. The tester can indicate three fault conditions: open circuit, ground fault and cable fault, namely resistance breakdown. The cables on each side connect the thermocouples.

The experimental steps include: controlling the flame temperature of the furnace at 1000-1050°C, and detecting the structural integrity and temperature of the cable. The two criteria for judging failure are: (a) the integrity of the cable is maintained for 15 minutes and (b) the cable temperature is maintained for 15 minutes when the temperature is below 95°C.

Result

Aluminum:The aluminum ladder frame gradually collapsed, and the cable was damaged in less than 5 minutes. One side of the galvanized steel support leg began to collapse in 2 minutes, and after another 1 minute, the stainless steel leg was partially deformed, and the ladder frame collapsed in 4 minutes and 41 seconds.

Stainless steel:Fully meets the test standards, the test lasted more than 15 minutes. The cable on the side of the stainless steel support leg was damaged after 26 minutes, and the cable on the side of the galvanized steel support leg was damaged after 33 minutes. The time for the temperature of the cable on the side of the stainless steel support leg to rise above the specified 95°C is 21 minutes, and the time for the temperature of the cable on the side of the galvanized steel support leg to rise above the specified 95°C for 26 minutes.