Ultrafiltration usually uses a hollow fiber membrane, and the raw water is pressurized and flows in the outer or inner cavity of the hollow fiber device, and the 姗J constitutes an external pressure type and an internal pressure type. Ultrafiltration is a dynamic filtration process in which the trapped material can be removed with the concentrate without clogging the membrane surface. In the ultrafiltration process, as the trapped impurities accumulate on the surface of the membrane, a concentration polarization phenomenon occurs, and the water permeability of the membrane is lowered. Reasonable selection of operating conditions and cleaning processes can completely control the concentration polarization problem of ultrafiltration.

At the beginning of the operation, the ultrafiltration equipment is slowly boosted, and the waste water is discharged until the water is qualified. After long-term operation of the high-efficiency filter, due to factors such as the breeding of algae, the electrostatic attraction of colloids and fiber bundles, and the contamination of organic matter, the operation cycle is short, the interception capacity is reduced, and the pressure drop after water and gas washing is not obvious, and chemical reaction is required. Cleaning. Washing with 3 % NaOH, 0.55% NaCLO mixture, heating to 30 ° C, soaking the filter material for 24h, then gas-water washing, until the pH ≤ 8 end, the water reduction rate after washing can reach 98% or more, cut The sewage capacity is greater than 10 kg/m3.

The membrane flux of a general product is designed at 25 ° C. When it is inconsistent with the actual operating temperature, it should be divided by the temperature correction factor. The correction gets an approximation, ie

G=(1+0. 021 5)â–³t

â–³t=25-t

15%。 The output of the ultrafiltration device is related to the operating temperature, the viscosity of the water changes with the temperature change, the temperature per 1 ° C increase, the water permeability increased by 2. 15%. When the pressure difference exceeds 0.2 MPa or the turbidity exceeds 2 NTU, the filter exits the operation for gas washing. In addition, the filter must not be stopped during operation to prevent the filter layer from turbulence and agitation affecting the quality of the produced water. The daily cleaning of the filter is convectively flushed by the underwater intake air, and the intake air intensity is maintained at about 60L/(s·m3), so that the fiber bundle is fully agitated to achieve the purpose of completely removing the retentate.

[Introduction to the performance structure of household ultrafiltration equipment]

Ultrafiltration membranes are mostly made of acetate fibers or polymer materials with similar properties. It is most suitable for the separation and enrichment of solutes in solution, and is also commonly used for the separation of colloidal suspensions that are difficult to accomplish by other separation techniques, and its application fields are expanding. Membrane filtration based on pressure difference can be divided into three types: ultrafiltration membrane filtration, microporous membrane filtration and reverse osmosis membrane filtration. Their distinction is based on the minimum particle size or molecular weight that the membrane layer can trap. When the nominal pore size range of the membrane is used as a classification standard, the pore size range of the microporous membrane (MF) is 0.02 to 10 μm; the ultrafiltration membrane (UF) is 0.001 to 0.02 μm; and the reverse osmosis membrane (RO) is 0.0001 to 0.001 μm. A microporous membrane with a uniform pore size and a nominal pore size range of 0.001-0.02 microns. The membrane filtration method using an ultrafiltration membrane with a pressure difference as a driving force is ultrafiltration membrane filtration.

The ultrafiltration membrane can be used in the form of a flat membrane, a roll membrane, a tubular membrane or a hollow fiber membrane, and is widely used in, for example, the pharmaceutical industry, the food industry, environmental engineering, and the like. We all know that the sieve is used to sieve things, it can release small objects, and the larger ones are left behind. The ultrafiltration membrane is a porous membrane with super "sieving" separation function. Its pore size is only a few nanometers to tens of nanometers, which means that there is only one hair strand of one hair! Applying appropriate pressure on one side of the membrane can screen out solute molecules larger than the pore size to separate molecular weights greater than 500 dols. Particles having a particle size greater than 2 to 20 nm.

Ultrafiltration membranes are best suited for the separation and enrichment of solutes in solution or the separation of colloidal suspensions that are difficult to accomplish with other separation techniques. The membrane forming technique of ultrafiltration membranes, that is, the technique of obtaining the desired size and narrow distribution of micropores is extremely important. There are many control factors for the pores. For example, ultrafiltration membranes with different pore sizes and pore size distributions can be obtained according to the type and concentration of the solution during the film formation, evaporation and coagulation conditions. The ultrafiltration membrane is generally a polymer separation membrane, and the polymer materials used as the ultrafiltration membrane mainly include cellulose derivatives, polysulfone, polyacrylonitrile, polyamide, and polycarbonate.

The structure of the ultrafiltration membrane is symmetrical and asymmetrical. The former is isotropic, has no cortex, and the pores in all directions are the same, belonging to deep filtration; the latter has a dense surface layer and a bottom layer mainly composed of finger structures, and the surface layer thickness is 0.1 micron or less. And having ordered micropores, the bottom layer having a thickness of 200 to 250 microns, belonging to surface filtration. Ultrafiltration membranes used in industry are generally asymmetric membranes. The membrane materials of ultrafiltration membrane mainly include cellulose and its derivatives, polycarbonate, polyvinyl chloride, polyvinylidene fluoride, polysulfone, polyacrylonitrile, polyamide, polysulfone amide, sulfonated polysulfone, cross-linked Polyvinyl alcohol, modified acrylic polymer, and the like.

[Technical application of ultrafiltration equipment]

Ultrafiltration is a membrane separation process with separation principle and pressure as the driving force. The filtration precision is in the range of 0.005-0.01μm, which can effectively remove particles, colloids, bacteria, heat sources and high molecular organic substances in water. Can be widely used in the separation, concentration and purification of substances.

Early industrial ultrafiltration was applied to wastewater and wastewater treatment. Over the past 30 years, with the development of ultrafiltration technology, the application fields of ultrafiltration membrane technology have been widely used, including food industry, beverage industry, dairy industry, biological fermentation, biomedicine, pharmaceutical and chemical, biological preparations, and traditional Chinese medicine. Preparations, clinical medicine, printing and dyeing wastewater, food industry wastewater treatment, resource recovery, and environmental engineering. The raw water is pressurized and flows outside or inside the hollow fiber to form an external pressure type and an internal pressure type hollow ultrafiltration membrane. Ultrafiltration is a dynamic filtration process in which the trapped material can be removed with the concentrate without clogging the membrane surface and can be continuously operated for a long period of time.

The ultrafiltration membrane is divided into a plate-and-frame type (plate type), a hollow fiber type, a nanometer membrane type ultrafiltration membrane, a tube type, a coil type, and the like according to a structural type. Among them, hollow fiber ultrafiltration membrane is the most mature and advanced form of ultrafiltration technology. The hollow fiber has an outer diameter of 0.4-2.0 mm and an inner diameter of 0.3-1.4 mm. The hollow fiber tube wall is covered with micropores, and the pore diameter is expressed by the molecular weight of the retentate substance, and the molecular weight cut off can be several thousand to several hundreds of thousands.

The ultrafiltration process has no phase conversion and is operated at room temperature. It is especially suitable for the separation of heat sensitive substances, and has good temperature resistance, acid and alkali resistance and oxidation resistance. It can be continuously continuous under conditions of 60 ° C and pH 2-11. use.

[Ultrafiltration equipment use advantages]

Ultrafiltration membrane components use the world famous membrane company products to ensure that customers get the world's best quality organic membrane components to ensure the retention performance and membrane flux. The ultrafiltration equipment control system can be personalized according to the specific requirements of users. Combined with advanced control software, on-line online centralized monitoring of important process operating parameters, to avoid manual misoperation, multi-faceted to ensure long-term stable operation of the system.

Since each ultrafiltration unit is added with a protective liquid before leaving the factory, thoroughly rinse the protective liquid in the assembly before use. Rinse with low pressure (0.1 MPa) for 1 hour, then rinse with high pressure (0.2 MPa) for 1 hour. When the low pressure or high pressure flushing, the system's production water discharge valve should be fully open. When using water, check and confirm that the product water does not contain any fungicide.

The ultrafiltration equipment system has high recovery rate, and the obtained product has excellent quality, and can realize efficient separation, purification and high-concentration of materials. The system is made of sanitary grade pipe valve, which is clean and hygienic on site, meeting the requirements of GMP or FDA production regulations. The system has advanced technology design, high degree of integration, compact structure, small floor space, easy operation and maintenance, and low labor intensity.

The process has no phase change, has no adverse effects on the components in the material, and is always in a normal temperature state during separation, purification and concentration, and is particularly suitable for the treatment of heat sensitive substances, completely avoiding the disadvantage of high temperature damage to biologically active substances. Effectively retain bioactive substances and nutrients in the original material system.

Ultra-filter components should be handled with care and attention. Since the ultra-filtration components are precision equipment, be careful when using the installation, and take it lightly and gently. If the components are to be deactivated, rinse them with clean water, add 0.5% formaldehyde solution for disinfection, and seal them. If the winter components are still antifreeze, the components may be scrapped.

The ultrafiltration equipment system has low energy consumption and short production cycle. Compared with the traditional process equipment, the equipment operation cost is low, which can effectively reduce the production cost and improve the economic benefits of the enterprise.

[Application of Ultrafiltration Technology in Electrophoretic Coating Process]

Electrophoretic coating is a new type of surface treatment technology. Under the action of electric field, the charged electrophoretic paint is plated on the surface of metal to form a dense and smooth surface protection layer. This technology has the following advantages:

1. Improve the anti-corrosion and decoration of the product, simplify the surface treatment process and reduce the discharge of heavy metal wastewater.

2, using the gloss of the metal itself, electrophoretic coating on stainless steel, aluminum alloy, copper alloy and other materials, its transparent feeling, with metallic luster, and good anti-corrosion and decorative effects; for iron, zinc alloy, etc. Metals with discoloration on the surface can be replaced by translucent, matt or concealed electrophoretic coatings, which is beneficial to the diversification of products.

3. Significantly reduce the discharge of wastewater, which can reduce the processing cost.

4. For some plating materials that are difficult to use as the final coating alloy, electrophoretic coating may be performed thereon instead of chrome plating or nickel plating. In addition, electrophoretic coatings are also highly environmentally friendly in terms of environmental pollution and the use of organic chemicals. The specific performance is as follows: electrophoretic coating uses water-soluble paint, more than 80% of the paint is moisture, the solvent volatilizes little, and the pollution to the environment is correspondingly reduced. Electrophoretic coating mainly uses acrylic resin or epoxy resin (lead-free), which is not particularly toxic to human body. The paint brought out during the electrophoretic coating process can be recycled 100%. Therefore, electrophoretic coating is one of the most promising processes in the future development of coating.

In the electrophoretic coating process, the coated parts should be washed with a large amount of deionized water to enter the drying room, and the paint washed away by water accounts for about 30% of the used coating, which not only causes waste of resources, but also pollutes the environment. In 1971, PPG and Abcro jointly applied ultrafiltration to electrophoretic coating to achieve a complete water circulation system, which made the electrophoretic coating process more rational, saving labor, improving coating utilization, and reducing the pollution of electrophoresis wastewater. Stabilizing the paint tank, the coating quality of the workpiece is better. In addition, during the electrophoresis process, the conductivity of the electrophoretic paint solution in the electrophoresis tank will continue to rise, affecting the quality of the plated parts. Therefore, after a period of time, the paint liquid in the electrophoresis tank is needed, and the new paint liquid is re-blended with pure water. The electrophoretic paint in the effluent can be recovered using an ultrafiltration recovery unit. On the one hand, it saves costs, on the other hand, it can avoid the environmental pollution caused by the discharge of electrophoretic paint. So far, ultrafiltration recovery devices have become one of the indispensable key devices in a complete electrophoretic coating system.

KMP Parts

KMP Parts,KMP Engine Parts,KMP Auto Parts,KMP Excavator Parts

JINING SHANTE SONGZHENG CONSTRUCTION MACHINERY CO.LTD , https://www.sdkomatsudozerparts.com