Study On Waste Gas Purification System And Recovery Chamber Of Modified Asphalt Waterproofing Membrane Production

With the vigorous development of construction industry,waterproof materials as functional building materials have also been developed rapidly.More than 30 years since 1985,the output value of building waterproof materials industry in China has increased from 2.5 billion yuan to nearly 200 billion yuan.In 2018,there were 784 building waterproof materials enterprises with annual income of more than 20 million yuan,and the total annual production of modified asphalt waterproofing membranes was about 780 million m~2.Modified asphalt waterproofing membrane will produce a lot of waste gas in the production process.There are many problems in waste gas purification in domestic enterprises,such as complex process,low purification efficiency and difficult maintenance of equipment.At present,among the several waste gas purification methods that have been applied,combustion method has relatively high operating cost,and the high-temperature waste heat generated by waste gas combustion has high recycling value.However,due to the large initial investment in equipment,the related research and application of waste heat recovery in this kind of enterprises are less.Therefore,it is of great practical significance to optimize the waste gas purification system and to study the waste heat recovery and utilization of flue gas after combustion.In this paper,the waste gas purification system of modified asphalt waterproofing membrane production in Hangzhou JW Waterproof Material Company is taken as the research object.Based on the problems of disorderly equipment layout,difficult management and high energy consumption in operation,the combined purification mode of"high temperature combustion+waste heat recovery+spraying"is optimized through theoretical analysis and experimental research.The test and analysis of the optimized system which has been put into operation show that the average emission of pollutants is 92.53%lower than the limit stipulated in the Comprehensive Emission Standard of Atmospheric Pollutants GB16297-1996,and the purification effect of exhaust gas is ideal.The energy consumption of operation is greatly reduced after the optimization of the system.Because of the increase of heat recovery chamber,the annual consumption of natural gas for heating the heat conducting oil furnace in the production process is also reduced.The optimization cost of the waste gas purification system is about 300,000 yuan,and the cost of the optimized enterprise can be reduced by about 837,300 yuan annually,and the economic recovery period is less than half a year.By measuring the inlet and outlet temperatures of the heat recovery chamber of the waste gas purification system,the recovery efficiency of waste heat is 56.14%.It is found that the simple structure of heat exchanger tube in heat recovery chamber is the main reason for the low efficiency of waste heat recovery.Therefore,this paper aims at further optimization of heat exchanger tubes in heat recovery chamber.Based on the numerical simulation method,the influence of structural parameters on heat transfer performance and flow resistance of heat recovery chamber when finned tubes are used in heat recovery chamber is deeply studied,and the advantages and disadvantages of comprehensive performance of different finned tubes are compared and analyzed.The results show that compared with smooth tubes,the heat transfer capacity of rectangular louvered finned tubes in heat recovery chamber increases by about 12%,and the comprehensive performance is the best.The second is corrugated finned tube,which increases the heat transfer by about 11%.The heat transfer performance of Y-shaped finned tube is slightly better than that of rectangular flat finned tube,but its comprehensive performance is the worst.Finally,through theoretical analysis,it is concluded that when finned tube is used to recover waste heat in heat recovery chamber of waste gas purification system,the annual consumption of natural gas in heating oil furnace is reduced by about 75744 m~3,which has more energy-saving advantages.In this paper,the optimization of the waste gas purification system and the heat exchange tube of the heat recovery chamber have been preliminarily completed.It provides a certain reference for improving the engineering design and application of waste gas purification system and waste heat recovery in asphalt waterproof membrane production.It is conducive to the development of energy saving and emission reduction related technologies,and is of great significance to improve energy utilization and reduce energy consumption.