| Drinking water scale is a general concern of users.It not only affects the sense of drinking water,questioning the safety of drinking water,but also easily scales on the walls of water supply facilities and drinking vessels,which affects users’ lives and industrial production.Existing water quality indicators for raw water testing cannot directly reflect the amount of scale generated in boiling water,and there are large differences in scaling on different walls under the same conditions,indicating that wall materials and surface characteristics have an important influence on scaling.Based on the generation principle of boiling water scale,this paper proposes a rapid detection method of boiling water scale generation,and explores the formation and adhesion characteristics of scale on different wall interfaces.The research results provide a theory for the improvement of drinking water quality and the selection and development of water supply facilities.support.Boiling water destroys the carbonic acid balance of drinking water to form scale.It is proposed that negative pressure destroys the carbonic acid balance to form scale,establishes the relationship between the difference in turbidity caused by scale and the amount of scale generated,and establishes a rapid detection method for the amount of scale generated in boiling water;choose common copper,Stainless steel,galvanized,iron,aluminum,glass,PE,PPR 8 kinds of plates,after repeated long-time boiling water scale,determine the amount of scale adhesion,corrosion amount,scale coverage morphology,adhesion crystal form and stickiness on the interface of different plates Attached to the macro characteristics of material surface fouling such as performance;with the help of scanning electron microscopy,the relationship between the surface characteristics of the material and the initial fouling characteristics is explored;the interface atomic force between the material surface and the scale is used to explore the adhesion and accumulation of scale on the surface of different materials The cause of formation.The conclusion of this paper is as follows.(1)The cause of scale is that the temperature rise destroys the carbonic acid balance,the negative pressure is used to quickly destroy the carbonic acid balance in the water,the function between the scale and the turbidity difference is established,and the rapid detection method and the corresponding device for the boiling water scale are proposed.(2)The study of the macroscopic characteristics of scaling shows that the adhesion amount on the iron surface is the largest(59.0mg),and the adhesion amount on the PPR surface is the smallest(10.5mg);the corrosion quality of iron is the largest(12.5mg)in the corrosion quality of the material,and the non-metallic material is basically free For the selection of materials,it can be seen that the better the corrosion resistance of the material,the more difficult it is to scale;for the macroscopic scale coverage,the scale on the wall surface of the device after repeated boiling of water is different.Galvanized and iron are mainly Exist as aggregated layered scale,stainless steel,copper,aluminum and three non-metallic plates are mainly granular scale.It can be seen that the distribution form of scale on the surface of the material is the cause of the huge difference in macroscopic scaling: if the surface of the material forms a layer of scale,it will accelerate the subsequent scaling,and the formation of scattered particle scale will prevent subsequent scaling..The surface of stainless steel,iron,and aluminum are mainly calcite,while copper and galvanized surfaces are mainly aragonite,with a small amount of calcite and calcium oxalate.The surface of glass is mainly aragonite,the surface of PPR is mainly calcium oxalate,and the surface of PE is vaterite;the use of ultrasonic to remove the scale attached to the plate found that the removal effect of galvanizing is the worst,followed by copper,aluminum,iron,and stainless steel,followed by non-metal The removal of the plate is the best.(3)The study on the microscopic characteristics of scaling shows that under four scenarios(60℃,p H=7,80℃,p H=7,60℃,p H=9,80℃,p H=7),no matter which one Under the scenario,the surface of iron has the largest single scale scale and the fastest growth rate,while the single scale scale on glass has the smallest amount and the slowest growth rate.For the material properties,the roughness of the material surface is easy to provide more nucleation sites,which causes the scale to accumulate in some specific areas and mainly distributes in layers,so that large scale scale will be formed later and cover the surface.On the contrary,scattered particles of scale will be formed.The larger the contact angle,the larger the amount of scale adhesion in the early stage,which will affect the macroscopic scale quality.The surface free energy affects the morphology changes at the initial stage of scale and thus affects the macroscopic crystal form.High surface energy will form more aragonite or mixed crystal forms,and low surface energy will form more calcite.(4)Using atomic force microscopy to measure the forces on the surface of different materials and after the formation of the scale layer,it shows that when the surface of the material is hydrophilic,a thin water layer is easily formed on the surface of the material,which can effectively prevent scaling;the adhesion between scales in different periods of time Affected by the characteristics of the first fouling,the adhesion force between the particles when the scale layer is not formed is less than the adhesion force between the particles when the scale layer is formed.The reason may be that the scale layer causes the adhesion interface roughness to increase and the adhesion force increases.The scale particles are easy to aggregate and form different scale covering morphologies. |
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