Single-material gradient filter element

Abstract

The invention provides a single-material gradient filter element. The filter element comprises at least two filter layers which have the same density and are formed by hot-melting and winding of polypropylene fiber yarns; and polypropylene fiber yarns of the filter layers from outside to inside have different thicknesses, and polypropylene fiber yarns of the outer layer are thicker than those of the inner layer. According to the single-material gradient filter element, gradient filtration of the filter element can be realized by changing thickness of the polypropylene fiber yarns of different filter layers. According to the gradient filtration realized by the manner, the density of each filter layer is the same, namely the compact degree of each layer is the same, so that the filter element has relative good strength and strong tensile strength, and has a relatively long service life since the filter element cannot be easily extruded and deformed in the filtering process. Furthermore, due to relatively high strength, a frame structure does not need to be added inside the filter element for supporting, so that the filtration flux and assimilative capacity can be ensured, and materials can be saved.

Description

Technical field [0001] The invention relates to the technical field of water treatment, in particular to a single-material gradient filter element. Background technique [0002] Polypropylene filter element is a filter device in which polypropylene particles are melted, sprayed into fine fiber filaments and tightly wound to form a white tubular filter element, which has better air permeability and can be used in water filtration treatment. [0003] The Chinese patent document with the publication number CN2568276Y discloses a gradient filter element, which has a central framework and a filter layer, and the filter layer is composed of two or more layers of gradient filter layers whose filter pore size decreases from the outside to the inside. The gradient filter element can make full use of each filter layer to achieve a better filtering effect. However, the filter pore size of this gradient filter element decreases from the outside to the inside by changing the density of the filt...

AI Technical Summary

Problems solved by technology

However, due to the low density of the outer filter layer, that is, the outer filter element is relatively loose, it is easy to be squeezed and deformed under the pressure of water flow, and the filtration flux and dirt holding capacity will be seriously affected after compression. Increase the skeleton structure to support the filter element, however, the skeleton structure is usually made of impermeable materials such as engineering plastics and stainless steel, which blocks the flow of water and reduces the filtration flux

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