In the past, most flues were prefabricated with sulphoaluminate cement and alkali-resistant glass fiber mesh or ordinary silicate cement and steel wire mesh. Due to the mandatory provisions of the national standards "Code for Design of Residential Buildings" and "Code for Fire Protection of Building Design", the fire resistance limit of smoke exhaust pipes in residential buildings should not be lower than 1.00h, and it is difficult for cement prefabricated flue to meet the fire resistance limit requirement of not less than1.0h. In order to prevent the accumulation of grease in smoke exhaust pipes in residential buildings from becoming a fire hazard for a long time, Most of the smoke exhaust pipes are high-strength fire-resistant smoke exhaust pipes assembled by using the new patented technology of Jiangsu Zitai Institute of Building Technology, and the high-strength glass-magnesium fire-resistant flue plates are mechanically combined. The variable-pressure air extraction components are installed in the flue, and the type inspection must be carried out according to the national standard GB/T 17428-2009, and the fire resistance limit should be greater than1.0h; The invention has the characteristics of light weight, high strength, no deformation, good fire resistance, strong flexible impact resistance, easy installation, good sound insulation performance and no damage. Widely used in kitchen exhaust and bathroom exhaust of residential buildings and public buildings.
When the flue gas from the air inlet is discharged into the flue, it will meet the flue gas discharged upward from the lower floor. When the two air streams meet, a vortex and an air curtain will be formed, which will hinder the upward movement of the lower flue gas. Once the fire check valve is stuck by oil pollution and can't be opened, the smoke will flee indoors because of its upward movement.
In order to overcome the technical problem of smoke smell, the solution is to use the dynamic and static pressure conversion principle of aerodynamics (Bernoulli theorem) and the combined variable pressure fire-resistant flue developed by Wei Zi Institute of Architecture and Technology in Jiangsu Province, and set a patented variable pressure check element in the flue to extract air and accelerate air flow, so that the dynamic and static pressure conversion of flue gas can be completed at a specific position, so that the exhaust port of the kitchen or bathroom where the range hood cannot be opened is in a negative pressure state, and the suction force is formed by using Bernoulli theorem principle. The combined variable pressure fire-resistant flue passed the scientific and technological achievements appraisal of the Science and Technology Development Promotion Center of the Ministry of Construction on February 12, 2002. The evaluation conclusion is that this product can effectively solve the problems of gas vortex, gas curtain blockage, flue gas backflow and flue gas odor, meet the needs of residential construction, and has the functions of preventing flue gas cross-flow, backflow, fire resistance and fire prevention, reaching the leading level of similar products in China. This achievement was listed as the 20 12 national promotion project of scientific and technological achievements in construction industry.
Reference link: Flue _ Baidu Encyclopedia
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