Sedimentation combined with a broad particle size distribution in the suspension results in multilayered filter cakes, where a fine particle layer forms on top of a compressible bottom layer. Owing to their high resistance, the fine particles act as a stiff layer and compress the bottom layer during filtration. This was investigated using a model cake composed of a compressible bottom layer and an artificial fine layer. Compression was determined via a volumetric porosity measurement. A reduction in porosity due to compression increased the filter cake resistance significantly. The use of different types of fine particles demonstrated that if the top layer resistance is higher than that of the bottom, a differential pressure results that pulls the top layer down and compresses the bottom layer.

中文翻译：

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多层滤饼的压缩机制

沉淀与悬浮液中较宽的粒度分布相结合，形成多层滤饼，其中细颗粒层形成在可压缩底层的顶部。由于它们的高阻力，细颗粒充当硬层并在过滤过程中压缩底层。这是使用由可压缩底层和人造精细层组成的模型蛋糕进行研究的。压缩通过体积孔隙率测量来确定。由于压缩导致的孔隙率降低显着增加了滤饼阻力。使用不同类型的细颗粒表明，如果顶层电阻高于底层电阻，则会产生压差，将顶层拉下并压缩底层。