Technical analysis of the ultrafiltration membrane in water softening equipment

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This post was last edited by Yamei on 2016-5-15 08:08. The bundled ultrafiltration membrane fibers for soft water treatment equipment are processed through a casting technique to create the ultrafiltration element shown in the figure below. This element consists of an ABS housing, epoxy end caps at both ends of the housing, and the bundled ultrafiltration membrane fibers. The epoxy seal fills the gaps between the membrane fibers, creating a barrier between the feed solution and the permeate. The feed solution first enters the pores of the ultrafiltration membrane; after being filtered by it, it becomes the permeate, thereby preventing the feed solution from entering the permeate directly without being filtered. Tap water first enters the ultrafiltration membrane tube; under the effect of pressure difference, the numerous 0.01-micron pores distributed across the surface of the membrane in the water softening equipment allow only water molecules, beneficial minerals, and trace elements to pass through, resulting in purified water. Harmful substances such as bacteria, rust, colloids, sediment, suspended particles, and large-molecule organic compounds are retained within the ultrafiltration membrane tubes and are removed during the flushing of the membrane. 　　With the water production rate per unit area of the membrane fibers in the unit’s water softening equipment remaining constant, the larger the membrane area occupied by the filter elements, the higher the total water production volume of those elements. An ultrafiltration membrane is composed of hundreds to thousands of tiny hollow fiber filaments. Ultrafiltration membranes with an inner diameter ranging from 0.6 to 6 mm are generally referred to as capillary-type ultrafiltration membranes. Due to their larger inner diameter, capillary-type ultrafiltration membranes are less likely to become clogged by large particles. After being used for a period of time, the ultrafiltration membranes in water softening equipment accumulate harmful substances such as bacteria, rust, colloids, suspended particles, and large-molecule organic compounds on their inner surfaces. This leads to a gradual decrease in the water production capacity of the membranes. Especially when the quality of tap water is poor, this can easily cause blockages in the ultrafiltration membranes. Regularly flushing these membranes can help restore their water production capacity. 　　With the continuous advancement of membrane separation technology, reverse osmosis systems are now commonly used for filtration, or ultra-pure water is produced by using a first-stage reverse osmosis system followed by an ion exchange mixed-bed (or electrodeionization EDI) process.