Microfiltration apparatus for processing recycled water installation site
Summary of circulating water purification
Circulating water system scaling is due to a combination of calcium and magnesium ions and ions generated, the higher the temperature the faster the more severe scaling trend, mainly due to high temperatures reduce the solubility and precipitation of salts is further attached to the wall junction scale into a variety of different components. Scale formation is not instantaneous, but there is a precipitate, participation circulation, gradually gathered, nucleating grew attached fouling process, if the destruction process to a certain extent, it can delay the scaling, the more thorough destruction the fewer, the fouling.The technical means to destroy this process is the formation of aggregates grew in scale process to filter out as much as possible.
Many factors affect the circulating cooling water corrosion of metal heat transfer equipment, summed up can be divided intoChemical factors、Physical factors等。
Circulating water system not only absorbs the air suspension in the cooling process, and the system itself also generates particulate impurities. Products include system corrosion, mineral deposits (such as iron and hardness salts, etc.), microbial growth, organic aggregates, surface heat exchanger leak coming from the process of dissolution and the insoluble impurities and so on, increasing the system of nutrition, accelerate the growth of bacteria , accelerated corrosion and the formation of corrosion products. When the impurities and scale of mineral deposits, when combined, will increase the thickness of the fouling rate and fouling. These membrane fouling reduces the heat exchange efficiency and reduce the water flow rate of the heat exchanger surfaces, and promotes corrosion under the dirt, resulting in more pollution. Slower flow rates allow more impurities precipitate, magnified the problem, further reducing the efficiency of the cooling water of microorganisms, especially those capable of producing slime of microorganisms deposited on metal surfaces (not just the microorganism itself, but also the adhesion of the water suspended solids), can also cause corrosion under the scale. Meanwhile, some microbial metabolism are also involved in the electrochemical process, promote accelerated corrosion.
Therefore, if we can very effectively remove fine suspended solids, it can reduce the causes of system integration corrosion, thereby reducing the corrosion rate, extend equipment life and non-normal shutdown caused by corrosion.
Because there are plenty of circulating water dissolved oxygen, suitable temperature and nutrient-rich conditions, it is suitable for microbial growth and reproduction, if not controlled it will quickly lead to deterioration of water quality, smelly, dark, cooling tower or even blocked a lot of sticky dirt deposition, cooling the cooling effect of a substantial decline, exacerbated by corrosion of the equipment. Therefore, circulating water must be controlled propagation of microorganisms.
Circulating cooling water of microbes from two aspects. First, the cooling tower during evaporation of water need cited
The large amount of air, microbes in the air into the cooling water, the second is the cooling water system to add water more or
There will be fewer microorganisms that also with the supplementary water into the cooling water system.
Algae in sunlight exposure, will work with carbon dioxide, bicarbonate and other water carbon from photosynthesis, absorb carbon and release oxygen as a nutrient, therefore, when the algal blooms will increase the dissolved oxygen content of the water is conducive to oxygen the depolarization, thereby accelerating the corrosion process. Microorganisms in circulating water systems multiply, will form a large slime the cooling efficiency of the cooling tower is reduced, sticky mud deposited in the heat exchanger, the heat transfer efficiency and reduce head loss increases, clogging pipes, deposited on metal surfaces the slime can cause severe corrosion under the scale,
In particular, the role of slime isolated metal corrosion and scale inhibitors, so that agents can not achieve the desired corrosion and scale performance. In addition to microbial slime will accelerate corrosion under the scale, but some bacteria in the metabolic process, biological secretions also corrosion of metal directly. All these problems led to the circulating water system can not operate long-term security, affecting production, causing serious economic losses, therefore, microbial hazards and scale, corrosion of the cooling water system is the same as serious harm, or even can be said that the three comparison control microbiological hazards is paramount.
Therefore, if we can clear or filtered to remove microbial slime, will greatly improve the quality of recycled water. Bring economic benefit.
Replenishment of circulating water should be carried out every day, even though a relatively small amount of water daily supplement, but there will be the cumulative effect, the quality of water will affect the quality of the circulating water, including turbidity, suspended solids, microbes, slime or viscous substance, to conserve water, a lot of water from surface water or sewage treatment secondary sedimentation tank effluent, the water looks decent, such as relatively clear, but the physical and chemical indicators are not necessarily ideal, they will shift to the accumulation of circulating water in the above-mentioned sticky mud or dirt, mainly including, but not limited to, the following:
●After precipitation with direct replenishment of surface water, water fine suspended solids, colloids, organics, microbiological directly into the circulating water extraction, and some enterprises in the water treatment, most are dosing PAC, but the resulting floc filtered is not complete, but dosing PAC produced alum is a very viscous suspension, they will work with other salts formed by mixing dirt.
● In sewage treatment terminal ------- secondary sedimentation tank effluent as a circulating water replenishment, general secondary settling tank craft sewage effluent suspended solids ss about 30-70mg / L, this suspension is itself a bioadhesive mud, is an aggregate of microorganisms, if they are directly added directly into the circulating water equal to a viscous material.
● As can be seen from the above, the circulating water replenishment should be careful to use after treatment compliance should, in addition to the standards prescribed by the state water standards, in particular, should focus on suspended solids and viscous substance, the water treatment process design should be reflected,For example, using the company's Beijing drop microflocculation + microfiltration technology as a means of water treatment technology, with good results. Microflocculation is ultra-fine powders as a substitute PAC flocculant, the first does not produce a viscous substance, the second also adsorption sticky substance, microfiltration is the high-precision filtration equipment, after microflocculation can not conventional stirred tank, settling pool technology directly into the microfiltration equipment, filtration accuracy of 1 micron or less, can absorb large amounts of colloidal material trapped. Thus providing a better quality of recycled water replenishment.
water system due to the oxygen content, temperature and other factors
will produce algae, bacteria will breed, so to join the fungicide, tiny
suspended solids, microbial debris, microbial metabolites mixed together
to produce a slime, and therefore need to add a release agent, . water contains a lot of ions (especially Ca, Mg ions). After the
water is concentrated over ion solubility party, thereby forming a
fouling corrosion, so to join the corrosion inhibitors,
● Join fungicides final form algae and bacteria debris, they will join the ranks of suspension participation form dirt, therefore, if we can filter out these substances, it will help purify the system.
● release agent is added so that dirt can be easily peeled off, but later flaking or falling into the water, sump or sedimentation tank often too late to precipitation or precipitation is not complete, therefore, as suspended solids floating in the water, dirt or form involved in the grain formation of scale Nuclear. If it will help the system to filter out and clean purify
● corrosion and scale inhibitor added is intended to reduce the metal pipe corrosion and scale, but when the wall of dirt is formed, the effect will be reduced, because the dirt wall cut off contact with the agent, in between the wall and the dirt anoxic zone is conducive to the growth of anaerobic bacteria multiply, they decompose sulfate in water to produce hydrogen sulfate cause corrosion of carbon steel.
In summary, the use of high-precision filter side measures (such as a drop of water saving microfiltration Beijing) can bring a range of positive effects for the circulating water quality. In particular, the removal of fine suspended solids and biological slime, can reduce the surface tension of the liquid, improve the cooling effect, reducing scaling, reducing corrosion under the scale, reducing pipes get clogged, reducing accidents squib, improve concentration ratio, improve the degree of vacuum generators to improve refrigerator efficiency, efficient use of agents or reduce the dosage.
Beijing drop of water Environmental Science and Technology Co.,Ltd.