Although ultrafiltration technology started late in my country, it has developed very rapidly. With the continuous promotion of this technology and the continuous improvement of people’s understanding of it, the beverage production industry will surely gain more benefits from it.
Ultrafiltration membrane equipment has several different forms such as flat plate, tubular, spiral plate and hollow fiber in industrial applications. At present, most of the domestic applications are plate and tubular, especially hollow fiber membranes (hollow fiber membranes) have also been widely used in water treatment.
Hollow fiber ultrafiltration membrane is a relatively mature and advanced form of ultrafiltration technology. This kind of membrane is developed on the basis of flat membrane with spatial three-dimensional geometry, so that the unit volume of membrane equipment does not rely on thinner semi-permeable membranes and has great membrane permeability. The wall of the hollow fiber tube is covered with micropores, and the pore size is expressed by the relative molecular mass that can intercept substances, and the relative molecular mass of the intercepted material can reach several thousand to several hundred thousand. Due to the hollow cylindrical configuration, the production capacity of the membrane permeation equipment per unit volume is greatly improved. The raw water flows under pressure on the outside or the inner cavity of the hollow fiber, forming an external pressure type and an internal pressure type, respectively. Ultrafiltration is a dynamic filtration process, and the entrapped substances can be removed with the concentration, without blocking the membrane surface, and can run continuously for a long time. It can be proved that in the application of ultrafiltration, using a cylindrical bundle of small diameter hollow fiber membranes of reasonable size, the amount of permeate will be equivalent to that obtained on an ultra-thin flat membrane of more than ten square meters.
The hollow fiber is a slender membrane tube, the inner wall is a membrane layer, the membrane layer is combined with the outer wall of the sponge type, the outer wall has coarse pores, and the inner layer plays the role of ultrafiltration separation. The size of the intima pore determines the size of the blocked material in the tube. The hollow fiber has an inner diameter of about 200 μm and is made of an inert non-ionic polymer with a unique anisotropic (skin) structure and significantly high flow rate. Its characteristics are: 1. The membrane area per unit volume in the device is large; 2. The membrane wall is thin, and the liquid permeation speed is fast; 3. The geometric configuration of the hollow fiber has a certain pressure resistance, so the strength is high.
(3) Water sterilization and disinfection equipment
(1) Ozone sterilizer
The so-called ozone sterilizer uses the strong oxidizing properties of ozone to achieve the purpose of sterilization. Ozone is a strong oxygen agent, and its bactericidal effect is 15∽30 times higher than that of chlorine. Under a certain concentration of 5∽10min, ozone can sterilize all kinds of fungi. It has been widely used in water disinfection treatment for deodorization and color removal in foreign countries, and it is also widely used in sterilization in the production of mineral water and purified water in China.
(2) Ultraviolet sterilizer
When microorganisms are irradiated by ultraviolet light, the proteins and nucleic acids of microorganisms absorb ultraviolet spectrum energy, resulting in protein denaturation and death of microorganisms. Ultraviolet rays have a certain penetrating ability to clean and transparent water, so it can disinfect the water. Ultraviolet sterilization cannot change the physical and chemical properties of water. It has fast sterilization speed, high efficiency and no odor, so it is widely used.