Research on advanced fire warning technology utilizing thermo-sensitive material modified conveyor belts

In the process of coal mine transport belt fire, CO and smoke are mainly produced, and CO as the indicator gas is susceptible to interference. When smoke is produced, it indicates that the conveyor belt has reached a high temperature, which risks missing the optimal time for extinguishing fires and ensuring personnel safety. To address this issue, an innovative method is proposed to modify the cover layer of conveyor belt using the thermo-sensitive material. This physical modification involves implanting the thermo-sensitive material to the belt. To evaluate the effectiveness of this modification, tests are conducted using a temperature-programmed oxidation furnace, a comprehensive thermogravimetric analyzer and the conveyor belt roller friction testing device to measure the changes in initial temperature, gas production rate, and volume fraction of indicator gases before and after the modification. Experimental results demonstrate that the physical modification with the thermo-sensitive material has minimal impact on the structural strength of the conveyor belt, and does not increase the risk of fire occurrence or spread. The unmodified transport belt produces CO as an early indicator gas at around 110 ℃, but its volume fraction and release rate are low, making it susceptible to misjudgment due to the presence of CO from other sources in the mine. The modified transport belt, on the other hand, detects the decomposition of the thermo-sensitive material in the belt's cover layer, generating the indicator gas that do not naturally occur in the mine at temperatures of 70−80 ℃. Compared to the unmodified belt, the modified belt enables earlier detection of the initial indicator gas by about 30 ℃, with a higher release rate and volume fraction, making monitoring easier. Moreover, the feasibility of the physical modification method is further substantiated from the perspective of practical engineering application. The indicator gas produced by the decomposition of the thermo-sensitive material is not affected by gases generated through oxidation of other materials in the mine, ensuring timely and accurate monitoring and warning of potential fires in the conveyor belt.