The Research On Combustibility Of The Sediment In Ventilation And Air-conditioning Systems And How It Affects Building Fire

Human beings call for safe living and working conditions, which is basic reqirement. Fire because of losing control of combustion, not only results in pesonnal casualty and property losing, but also brings enviroment pollution and zoology unbalance. Along with develoment of the society and progress of the sciece and technology, heating and air-conditioning systems are used more and more in morden buildings, which improve people's living and working conditions. As a results of gravitation, suspending particulate in the duct can subside in its suface, the sediment may threaten the safety of the building, because it can bring fire, or be an important way for fire spreading in the whole building.The article presents the force effected on the suspending particulate and its sedimentation act. In addition, the theoretical knowledge on the process of the fire occuring and expanding, how to prevent the fire and fire risk evaluation is introduced. The civil buildings (including kitchen, dinning room, underground garage and the office building) and the workshops (including cigarette factory and spinning mill) were chosen, the systems in which were for different use. Refering to the research approch for coal combustion characteristic, the test results of the samples collected from the duct surface were got by proximate analysis and ultimate analysis, including C_ad, H_ad, N_ad and S_ad (ad is short for air dry), kindling temperature (the samples are in nature state) and so on. The date confirms the combustibility of the sediment, which is potencial risk for buildings.In this paper, it analysises the factors that affect the combustibility of the sediment and how it effects on occurrence and spread of the building fire. Combined with these factors, some measures including design, maintence and management of the systems to reduce fatelness the sediment brings are suggested. It supplies the further research on building safe and sound heating and air-conditioning systems with the theoretic basis and testing support, and it afford referrence for establishing the criterion on fire's prevention and cure .