城镇二级出水换热表面混合污垢的成分及形貌

Composition and morphology of composite fouling by municipal secondary effluent on heat transfer surfaces

城镇二级出水中的致垢成分将导致热能回用过程中污垢的生成。该文在热泵工况下对二级出水在板式换热器内形成的污垢进行了成分及形貌的研究。实验结果表明:热泵工况下,二级出水在板式换热器内形成的污垢是以微生物污垢为主的混合污垢;污垢特性与二级出水的致垢成分存在密切关联;混合污垢表层结构呈空间网状,微生物及其胞外聚合物大量捕获水体中的无机悬浮物,无机悬浮物同时构成了微生物生长繁殖的节点。上述结果为城镇二级出水的热能回用提供必要的基础数据。

Fouling caused by municipal secondary effluent in a plate heat exchanger was investigated for typical working conditions of heat pump heat exchangers. The experiments focused on the composition and morphology of the above fouling. The results show that the fouling by the municipal secondary effluent in the plate heat exchanger is a composite substance consisting mainly of biological products. Thus the fouling characteristics are closely related to the substances in the effluent. The surface structure of the fouling forms like a mesh and the the microbes and extracellular polymeric substances capture inorganic suspended solids in the effluent. The inorganic suspended solid then becomes nodes for microorganism growth and reproduction. The experimental results provide essential information for the design of waste energy recovery from municipal secondary effluent.