Preparation method of special-shaped hollow fiber ultrafiltration membrane, special-shaped PVDF hollow fiber ultrafiltration membrane and application of special-shaped PVDF hollow fiber ultrafiltration membrane

Abstract

The invention provides a preparation method of a special-shaped hollow fiber ultrafiltration membrane. According to the preparation method,a membrane casting solution is unevenly discharged through a first metering pump, so that the membrane casting solution is unevenly fed when entering a spinning nozzle, the outer surface of a primarily-formed special-shaped hollow fiber ultrafiltration membrane is in a concave-convex shape; and a core solution is evenly discharged through a second metering pump, so that the core solution is uniformly fed when entering the spinning nozzle, so that the inner surface of the primarily-formed special-shaped hollow fiber ultrafiltration membrane is in a linear shape. The invention further provides a special-shaped PVDF hollow fiber ultrafiltration membrane and application thereof. The preparation method can stably control the size and shape of the outer diameter and the inner diameter of the membrane, ensures the periodic stability of the shape of the membrane, is high in repeatability, ensures the long-term stable use of the membrane, and is simple to operate, stable in performance and high in practicability.

Description

technical field [0001] The invention relates to the technical field of coal chemical sewage treatment, in particular to a preparation method of a special-shaped hollow fiber ultrafiltration membrane, a special-shaped PVDF hollow fiber ultrafiltration membrane and applications thereof. Background technique [0002] Due to its superior separation performance, ultrafiltration membranes have been widely used in coal chemical wastewater treatment projects. Used extensively in the food industry. Ultrafiltration membranes can usually use cross-flow filtration or full-flow filtration in the filtration process, but no matter what method is used, as the filtration time increases, membrane fouling, pressure difference increases or water production decreases will occur. The process of membrane fouling in actual use is as follows: First, at the beginning of the ultrafiltration membrane filtration period, macromolecular colloidal substances are continuously adsorbed on the surface of the...

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Problems solved by technology

The fiber membrane is obtained by periodically extruding the core liquid hose to obtain an uneven inner diameter and an uneven outer diameter of the membrane. However, due to the high viscosity of the casting liquid, its surface tension is relatively large and its elasticity is relatively large. Under the premise of controlling the inner diameter through the core fluid, it is difficult to control the outer diameter and outer shape, and at the same time, the shape of the membrane cannot be stably controlled, and the cycle stability of the membrane shape cannot be guaranteed, and the repeatability is poor, which affects the use effect of the membrane and is not conducive to Industrial production; in addition, when the flow rate of the liquid in the inner diameter is low, the uneven inner diameter makes the liquid in a turbulent state, and it is difficult to form a pulsed flow effect, and in the membrane, due to the uneven inner diameter, it is difficult to produce water and backwash During the process, the thinnest part of the inner diameter becomes the flow bottleneck, and the liquid flow resistance will increase significantly, and this structure also makes it difficult to control the wall thickness of the membrane filament. If it is too thin, the mechanical strength will be reduced, and if it is too thick, the membrane performance will be affected. In the actual application process, the production capacity of the equipment cannot be guaranteed

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