Research Of Slagging Experiment And Formation Mechanism Of Ash Deposits In The Waste Liquid Incineration Heat Recovery Steam Generator (HRSG)

Petroleum、weave、foodstuff and pharmacy generate a lot of wastewater in the process of production,incinerate these wastewater can not only recovery waste heat.but also protect the environment.But the question about clinkering is always a big problem in the HRSG.This text researched the ash deposits form burning the typical waste liquid in a petrochemical refinery company in China.Using the experimental method to analysis and discussion the mechanism of ash deposition process in-depth, The main research contents and results are as follows:(1) Analyze the industrial waste liquid in the refining device and the chemical fiber device.Using the spin steaming method to determine the industrial analysis and elemental analysis.The chemical waste liquid after the enrichiment is in weak acid,PH value is6.27.The content of S and N are high in the chemical waste solids,so the content of secondary pollutants(NOx、SO2/SO3) are on the high side.(2) Using intelligent ash melting point tester tests the ash melting point of ash deposits samples, along the gas flow direction, the melting characteristics of ash deposits samples show a trend of high to low.The characteristics melt temperature of ash deposits samples B and E are at top and bottom respectively.(3) Using X-ray fluorescence analyzer (XRF) and X ray diffraction (XRD) to determine the elements and the mineral composition of the ash deposits, the content of Na、S、Fe、Ni are more higher than others in furnace. Na in the waste heat boiler can be more evenly distributed, the percentage content of Fe and Ni along the flue gas flow direction gradually reduce, S is one of the important elements, its content gradually increases along the flue gas flow direction.The main sediment in the HRSG inlet are Na2SO4、NiO and Fe2.3Si0.7O4;The high and medium temperature area mainly desposits are Na2Ni(SO4)2·4H2O、Na3Fe(SO4)3and Na6Fe(SO4)4;The low temperature and economizer inlet area desposits are Na3Fe(SO4)3、 Na6Fe(SO4)4and Na2H(SO4)2·4H2O.(4) The main factors influencing the ash deposits in the HRSG includes micro partical collision、adhesion probability.Na is a unstable element released by incinerate waste liquid.and can reactive with SO2/SO3and Fe2O3to alkali metal compound sulfate Na3Fe(SO4)3. Fe and Ni are elements that difficult to volatilize, Fe and Ni are in the form of elemental or inorganic compounds and not combined with organic substances in the waste liquor, Fe and Ni generally in the form of high melting point and stable oxide exist in the larger size of fly ash particles, and mainly in the inertial collision mechanism of the deposit on the heat exchange tube wall surface. Si and Al elements have similar bond formed at a certain extent.