A, the hotel canteen water treatment equipment is divided into a variety of:
1. Different water purifier structures have different water purification effects. Generally speaking, the primary filtration water purifier is simple in structure, mainly made of activated carbon, with limited filtration capacity, and can only be used for coarse filtration. It is best to boil the filtered water and drink it.
2. Multi-stage filtration water purifier. This water purifier has two stages of coarse filtration and a set of fine filtration. The fine filtration mostly adopts hollow fiber filter element, and the filtered water can be directly drunk.
3. The water purification effect in reverse osmosis pure water machine is the best. It has three-stage pre-filtration, one-stage reverse osmosis membrane precision filtration and one-stage post-filtration. The filtered water contains no bacteria, viruses, heavy metals, pesticides, organic matter, minerals and strange colors. It's pure water. You can drink it without heating.
Second, according to the water quality, choose and buy the water treatment equipment of the hotel canteen.
1. The hardness of water is different in different areas. In the high-hardness water in limestone areas in northern and southern China, the content of calcium and magnesium ions is high and it is easy to scale. So you should choose advanced filtration water purifier and ion exchange resin filter element.
2. If the water contains chlorine with different colors and smells, and the city tap water contains more organic substances, you can choose a water purifier with a large activated carbon load. Because activated carbon has a strong adsorption effect on residual chlorine and odor in water, it has obvious removal effect on organic matter.
3. If you drink directly without heating, buy reverse osmosis pure water machine.
Third, the working principle of the water treatment equipment in the hotel canteen
Most water bodies in the world are seriously polluted, which aggravates the contradiction of water shortage. Traditional tap water treatment methods can no longer guarantee the provision of high-quality drinking water, and there are two major pollution problems in municipal water supply. High-rise water tank water supply and long tap water pipes will all cause potential pollution problems such as rust, scale and microorganisms. Therefore, various brands of water purifiers came into being. At present, the water purifiers on the market can be divided into the following types according to the water quality treatment methods:
1. Activated carbon adsorption
(It can be divided into the following three forms) Commonly used, it is made of carbon-containing substances such as essence, coal quality and fruit shell (core) by chemical method or physical activation method. It has a large number of micropores and specific surface area, so it has strong adsorption capacity and can effectively adsorb organic pollutants in water. In addition, during the activation process, some oxygen-containing functional groups are formed in the amorphous part of the surface of activated carbon, which makes the activated carbon have chemical adsorption, catalytic oxidation and reduction properties, and can effectively remove some metal ions from water.
2. Reverse osmosis membrane method
A membrane separation technology, which uses pressure to make water pass through a synthetic membrane, only allows pure water to pass through the membrane and excludes pollutants. The R/O reverse osmosis technology adopted is a high-tech achievement that the US government and NASA have spent hundreds of millions of dollars to solve the drinking water problem for lunar astronauts after years of efforts. The cost is high and it is suitable for areas with poor water quality.
3. Microfiltration and ultrafiltration
Microfiltration is a microporous membrane made of cellulose or polymer materials, which uses its uniform pore size to intercept particles, bacteria, colloids and so on. In water, so that they can be removed without a filter membrane. This microporous membrane filtration technology, also known as particle density filtration technology, can filter micron or nano particles and bacteria. Ultrafiltration and microfiltration are both membrane separation technologies, and there is no obvious boundary between them. The working pressure of ultrafiltration is generally about 0.3 MPa, which can remove macromolecular substances, bacteria, viruses, etc. from water, but the flux is low.
4. Compound type
When one process is difficult to remove harmful substances from water, two or more processes are adopted, which is called compounding. Such as activated carbon adsorption, ultraviolet sterilization, activated carbon adsorption, reverse osmosis, activated carbon adsorption, microfiltration (ultrafiltration), polypropylene superfine fiber, activated carbon, microfiltration (ultrafiltration) and so on. Among the composite water purifiers, the membrane technology composite water purifier has excellent water purification performance, especially in removing microorganisms (bacteria, algae and so on). ). Some excellent water purifiers can directly drink raw water, which has been welcomed by consumers and has become a hot spot in the development of water purifiers.
It is not difficult to see from the above classification methods of water purifiers that the water treatment equipment in hotel canteens is essentially a miniaturization of advanced water treatment, and its main treatment objects are turbidity, chromaticity, odor and organic matter in tap water. Generally, it consists of three parts: pre-filtration (coarse filtration), adsorption and fine filtration (microfiltration, ultrafiltration and reverse osmosis). Among them, adsorption (usually activated carbon adsorption) and fine filtration are the main means to remove organic matter, odor and chromaticity in water, and their objective operation directly affects the effluent quality of water purifier. Household water purifiers serve thousands of households. However, due to the great differences in water quality and water pressure conditions in the use areas, users lack the necessary operating knowledge, and the current product design cannot cope with the ever-changing situation. Therefore, water purifier manufacturers should consider letting users master certain professional knowledge, standardize the installation operation of water purifiers, and make the effluent water quality achieve the desired effect, so that users can rest assured.
The design and manufacture of water purifier is a comprehensive science and technology. The design principle of water purifier should be for the sake of users. As far as the characteristics of water quality in various regions of China are concerned, the organic pollution along the Yangtze River and densely populated areas is serious, while the problem of bacterial pollution exists in small water supply enterprises and groundwater use areas in villages and towns all over the country. Therefore, only some high-quality water purifiers can adapt to different water quality in different parts of the country, so water purifier manufacturers should carefully design water purifiers that can adapt to different water sources but have good treatment effect according to the water quality situation in different areas.
Four, the hotel canteen water treatment equipment ultrafiltration membrane filtration principle.
Ultrafiltration is a screening process using membrane separation technology. With the pressure difference between the two sides of the membrane as the driving force and the ultrafiltration membrane as the filter medium, under a certain pressure of ultrafiltration stainless steel water purifier, when the stock solution flows over the membrane surface, many tiny micropores on the surface of the ultrafiltration membrane only allow water and small molecular substances to pass through and become permeate, while substances larger than the micropores on the membrane surface in the stock solution are trapped at the liquid inlet side of the membrane and become concentrated solution, thus achieving the purpose of purification, separation and concentration of the stock solution.
There are about 6 billion micropores with a diameter of 0.0 1 micron per meter of ultrafiltration membrane wall, and the pore size only allows water molecules, beneficial minerals and trace elements in water to pass through, while the smallest bacteria are all above 0.02 micron, so bacteria, colloid, rust, suspended matter, sediment and macromolecular organic matter much larger than bacteria can be intercepted by ultrafiltration membrane, thus realizing the purification process.
The specific process is as follows:
1, ultrafiltration membrane water production process
Tap water first enters the ultrafiltration membrane tube. Under the action of water pressure difference, many 0.0 1 micron micropores on the membrane surface only allow water molecules, beneficial minerals and trace elements to penetrate and become purified water. However, harmful substances such as bacteria, rust, colloid, sediment, suspended matter and macromolecular organic matter are trapped in the ultrafiltration membrane tube and discharged when the ultrafiltration membrane is cleaned.
2, ultrafiltration membrane washing process
After the ultrafiltration membrane is used for a period of time, the trapped harmful substances such as bacteria, rust, colloid, suspended matter and macromolecular organic matter will adhere to the inner surface of the ultrafiltration membrane, which will gradually reduce the water yield of the ultrafiltration membrane, especially when the tap water is seriously polluted, which is more likely to cause the blockage of the ultrafiltration membrane. Regular cleaning of ultrafiltration membrane can effectively restore the water yield of membrane.
5. RO membrane filtration principle of water treatment equipment in hotel canteen.
The water purifier adopts RO reverse osmosis technology, also known as reverse osmosis, which is a membrane separation operation that uses pressure difference as driving force to separate solvent from solution. When pressure is applied to the feed liquid on one side of the membrane, when the pressure exceeds its osmotic pressure, the solvent will reverse the direction of natural permeation.
RO reverse osmosis membrane for water purifier is generally made of polymer materials. Such as cellulose acetate film, aromatic polyhydrazide film and aromatic polyamide film. The diameter of surface micropores is generally between 0.5 ~ 10 nm, which is usually said to be one ten thousandth of a micron. Includes removing impurities in ionic state. In today's endless stream of impurities, purified water has attracted more and more attention.
The principle of reverse osmosis is to apply a pressure greater than the natural osmotic pressure on the raw water side, so that water molecules can reverse permeate from the high concentration side to the low concentration side. Because the pore size of the reverse osmosis membrane is much smaller than hundreds or even thousands of times that of viruses and bacteria, all kinds of viruses, bacteria, heavy metals, solid soluble substances, polluted organic substances and calcium and magnesium ions cannot pass through the reverse osmosis membrane at all, thus achieving the purpose of water purification.