What Is a Thin Film Device?

Membrane separation equipment is a large-scale mechanical equipment manufactured in a production plant in accordance with its membrane separation technical parameter standards by using membrane separation technology. Its equipment can play a role of separation, and the effect is far beyond the traditional separation method.

Membrane separation equipment

Membrane separation equipment is a large-scale mechanical equipment manufactured in a production plant in accordance with its membrane separation technical parameter standards by using membrane separation technology. Its equipment can play a role of separation, and the effect is far beyond the traditional separation method.

Chinese name

Membrane separation equipment

Make use of

Membrane separation technology

Types of

Large machinery and equipment

Attributes

Selective separation of functional materials

Effect

Far beyond traditional separation methods

The core technology of membrane separation equipment is membrane separation technology. The separation membrane is a material with selective separation function. The working principle is the principle of physical mechanical sieving. The separation process uses the selective separation mechanism of the membrane to realize the separation between different components of the material and liquid. The process of separation or concentration of active ingredients.

Membrane separation technology equipment is different from traditional filtration in that the membrane can be selectively separated in the molecular range, and the cross-flow operation process of the membrane can solve the problem of pollution and clogging. It is a scientific and advanced separation technology and process.

The development and application of membrane separation technology should be based on the characteristics of the material system and process requirements, and carry out scientific verification in combination with experiments. While solving the problem of material refining, it must also ensure the feasibility of the process and is suitable for industrial clean production as the standard.

Used for

The main types of membrane separation equipment composed of organic synthetic membranes are: plate and frame type equipment. Between the sheet-like membrane groups of the same size, a separator is inserted alternately to form two kinds of liquid flow channels. Since the membrane group can be placed in a uniform electric field, this structure is suitable for an electrodialyzer. The plate and frame device can also be applied to ultrafiltration and dialysis with small hydrostatic pressure difference on both sides of the membrane. Spiral roll type device. A porous partition (a space for the permeate flow) is sandwiched between the two membranes, so that their three sides are adhered tightly, and the open side is joined with a porous central tube used as a permeate outlet tube. Then add a porous partition for the material liquid flow channel, and roll it together around the central tube to form a spiral-type element (Figure 1). The joining edge of the material liquid channel and the central tube and the outer end of the spiral roll are sealed. A plurality of spiral coil elements are put into a pressure-resistant cylinder to constitute a unit device. During the operation, the material liquid flows in the axial direction, and the permeable substance penetrates the membrane into the permeate space, and flows out along the spiral channel to the central tube. This equipment is suitable for reverse osmosis and gas osmosis separation, and cannot handle liquids containing fine particles. tube type device. Supported by a tubular membrane and supported by a porous tube, the composition is similar to

The equipment used for liquid film separation depends on the type of liquid film. When using emulsion film,

Production of fruit and vegetable juice

In the production of fruit and vegetable juice, microfiltration and ultrafiltration technologies are used for clarification and filtration; nanofiltration and reverse osmosis technologies are used for concentration. When the fruit juice is clarified by ultrafiltration, the bacteria will be trapped by the membrane along with the filter residue, and the bacteria mixed in the fruit juice can be removed without heating. The use of reverse osmosis technology to concentrate fruit and vegetable juice can improve the stability of the juice ingredients, reduce the volume for transportation, and can remove undesirable substances and improve the flavor of fruit and vegetable juice. For example, the aroma components in fruit and vegetable juices are almost completely lost during the evaporation and concentration process. The freeze-drying method can only retain about 8%, and the reverse osmosis technology can retain 30-60%.

For the dairy industry

Reverse osmosis and ultrafiltration technologies are mainly used for the recovery of whey protein and the concentration of milk. Compared with other methods, using membrane separation technology to process dairy products can reduce energy consumption and improve product quality. The application of reverse osmosis technology to the concentration of thin milk can produce cheese and sweet yogurt with satisfactory quality. Reverse osmosis technology is used to remove trace penicillin from dairy whey, which greatly extends the shelf life of dairy products. When ultrafiltration is used to concentrate whey protein, lactose and ash can also be removed at the same time.

Production of alcohol

Utilizing ultrafiltration technology can remove residual yeast, miscellaneous bacteria and colloidal substances in wine and alcoholic beverages. It can improve the clarity of wine and extend the shelf life. It can also make the raw wine mature and shorten the mature period. After the ultrafiltration treatment, the flavor of the wine is improved, it becomes refreshing and delicious, and the mellow and lingering. This method can also avoid the precipitation of turbid components easily caused by thermal sterilization of wine, and simplify the filtering equipment. The wines processed include wine, whiskey, shochu, sake, rice wine and so on.

Although the taste of draft beer is better than that of cooked beer, it cannot be stored for a long time, which brings certain difficulties to transportation and sales. Fine filtration and aseptic filtration of beer using ultrafiltration technology can make draft beer long-term storage without low-temperature heating and sterilization.

For the soy industry

The main application of membrane technology in the soybean industry is the separation and recovery of proteins. Soy whey produced during the production of soymilk can usually only extract 60% of the protein from it, and the residual protein can be concentrated by ultrafiltration, which can increase the yield of tofu by 20-30%. The ultrafiltration method can also remove the low-molecular substances that produce soy flavor and affect the stability of soy milk, while improving the quality of soy milk while condensing the protein.

The whey treatment in the soybean product industry is of great significance to prevent water pollution. Soy whey contains a variety of low-molecular-weight proteins, polysaccharides, peptides, low sugars and other substances. Ultrafiltration can be used to recover concentrated soybean protein from soy whey to meet the needs of human and animal husbandry. In addition, -amylase products are also available.

Functional ingredients such as soybean isoflavones, soybean oligosaccharides, soybean protein isolates, oligopeptides, immunoglobulins, bamboo leaf flavones and other functional foods can also be obtained using membrane technology.

For the condiment industry

More than 80% of the BOD in the wastewater from the sauce factory is mainly from the cooking juice of soybeans. The ultrafiltration method is used to process soybean boiled juice in stages. The permeate can be recovered as production water, and the concentrated liquid can be used as production raw materials.

application

1 Application of membrane separation technology in advanced treatment of urban sewage

Municipal wastewater advanced treatment and reuse began in the 1960s. Urban sewage has the characteristics of large volume, concentration and relatively stable water quality, and is a potential water resource. The advanced treatment of municipal sewage usually uses the secondary or tertiary discharge from the sewage treatment plant as the water source, and it is finally desalinized by reverse osmosis (RO), COD, BOD, and trace organic matter and heavy metal ions are removed. Meet drinking water standards. However, for some subjective reasons, most of them are not used directly as drinking water. Foreign countries often inject it into underground aquifers or freshwater reservoirs for natural purification (usually two years of storage), and also for non-drinking purposes such as industrial cooling water and boiler water. The shortage of water in the city restricts the development of the economy. The treatment and reuse of secondary effluent from the city is a way to solve the shortage of water resources. The secondary discharge liquid needs to be pre-treated before entering the RO device, so that the quality of the incoming water meets the requirements for use of the RO device. The pretreatment is the key to the success or failure of RO technology application. The advanced water treatment process using MF or UF pre-treatment before RO has become the industrial standard for urban wastewater treatment in indirect drinking water reuse projects. At home and abroad, membrane technology is actively used to develop urban wastewater into new water on a large scale. Resources. In China, "microflocculation fiber filtration + membrane filtration" has been used to study bathing wastewater. Tests show that this process has the characteristics of stable effluent and small footprint. The Tianjin Economic and Technological Development Zone Wastewater Treatment Plant introduces the Norwegian SBR sequential batch activated sludge process advanced technology, which can provide 100,000 tons of secondary biochemical treatment effluent as a water source every day, making it possible to reuse sewage after advanced treatment. The recycling and reuse of urban sewage in China is not widespread, and the application of membrane technology in advanced treatment is relatively rare. In the future, we need to conduct research on wastewater recycling and advanced treatment technology.

2 Application of membrane separation technology in industrial wastewater treatment

Due to the development of industry, a large amount of industrial wastewater is discharged into water bodies. These industrial wastewaters have a large area and are harmful, and most of them contain different concentrations of chemicals, some of which have high economic value, while others are toxic and harmful to the human environment. harmful. In order to protect the environment from pollution and recover useful substances, purification treatment must be performed before industrial wastewater is discharged. Membrane separation technology can not only effectively purify industrial wastewater, but also reuse useful substances in it, and it can also save energy. Membrane technology has been widely used in the five major categories of industrial wastewater: electroplating wastewater, papermaking wastewater, heavy metal wastewater, oily wastewater and printing and dyeing wastewater.

3 Application of membrane separation technology in drinking water treatment

With the improvement of people's living standards, the water quality requirements for drinking water are getting higher and higher. In addition, certain disadvantages in traditional processes, such as chlorination and sterilization, will cause chlorine to react with certain organic substances in the water to produce new harm. Trio (carcinogenic, mutagenic, teratogenic) compounds. Membrane technology is a major breakthrough for drinking water treatment.

Water purification and purification is the removal of suspended solids, bacteria, viruses, inorganics, pesticides, organics, and dissolved gases from water. In this regard, membrane separation technology has played a unique role. The water treatment method composed of microfiltration, ultrafiltration and nanofiltration in membrane separation is better than conventional water treatment technology in removing micron-sized particles in water, and it has the ability to remove nano-sized particles not available in filtration. The ability to effectively remove suspended solids, bacteria, viruses, inorganics, pesticides, organics and dissolved gases in water. Meet the requirements of drinking water quality improvement.

4 Application of membrane separation technology in seawater desalination

China is a country with large water resources and a poor country with water resources. As an important part of water resources, the effective use of seawater is one of the important measures to solve China's water resources crisis. The membrane technologies used for seawater desalination mainly include reverse osmosis, electroosmosis (ED) and membrane distillation (MD). In 2002, a 10,000-ton reverse osmosis seawater desalination and industrialization technology demonstration project for its organizer was included in the national high-tech industry development plan. The desalination rate of seawater desalination membranes is as high as 99.6%. The emergence and development of reverse osmosis technology has greatly reduced the cost of seawater desalination. Now reverse osmosis has become the most economical method for producing drinking water from seawater desalination. Electrodialysis technology can directly desalinate seawater into drinking water, but its process has no ability to remove uncharged substances such as organics, colloids, bacteria, suspended solids, etc., and it has high energy consumption and low water recovery rate. Therefore, due to the appearance of reverse osmosis seawater desalination technology, the proportion of seawater desalination by electrodialysis is gradually decreasing. Membrane distillation technology has a high desalination rate, which can reach more than 99.7%. It is used for small-scale seawater desalination. And has the advantages of simple equipment, easy operation, long membrane life, low energy consumption and so on.

5 Application of membrane separation technology in desalination of brackish water

The severe water shortage problem in China's western provinces and regions is particularly prominent in China, a water-scarce country. Desalination of brackish water is an effective way to solve the water shortage in China's western provinces. The membrane technologies used for desalination of brackish water are mainly electrodialysis technology, reverse osmosis technology and nanofiltration technology. Almost all oil fields in western China use electrodialysis to prepare drinking water. Electrodialysis cannot remove organic matter and bacteria in water, and the equipment consumes large energy, which limits its application in brackish water desalination projects. The brackish water can also be desalinated by a first-stage reverse osmosis device to obtain drinking water. The reverse osmosis system desalinizes brackish and salty water. Desalination of brackish water with high fluorine and low salinity through reverse osmosis, the quality of effluent water can meet China's drinking water hygiene standards. The reverse osmosis method has lower production cost and no pollution than the electrolysis method, and is the most economical method for desalination of brackish water. Nanofiltration is a low-pressure reverse osmosis technology that has higher desalination performance at lower pressures. It has a good desalination effect on specific solutes, especially the characteristic ions of brackish water. For western provinces and regions with more brackish and salty water, nanofiltration will be an effective way to produce high-quality drinking water.