Method for spraying and desalting through residual pressure of reverse osmosis concentrated water

Technical Field

The invention belongs to the field of water treatment technology, relates to industrial water treatment, environmental pollution treatment, sea water and myoporum saltiest salt water desalination, reverse osmosis system in the field of purification of the condensed water. More specifically it is a kind of reverse osmosis practical knowledge -odd pressure spray desalination method.

Background Art

Reverse osmosis technology utilize the external force (overcome the osmotic pressure) and by means of a film trap function is selected, the solute in the solution separation with a solvent, so as to achieve the purpose of the pure water. This technology has now been widely applied in industrial water treatment, environmental pollution treatment, sea water and myoporum saltiest salt water desalination, etc., but in the process, the material of the membrane , the influence of factors such as the types of water quality, desalting fine water generating at the same time there are a large number of tracing thick salt water discharge, water quantity of about 1/3 the left and right. Reverse osmosis concentrated salt water has a salt-containing high, containing difficult to degrade the contaminants and the like, thus existing conventional method is difficult to carry out effective processing.

In addition to the purposes of the present method, can be mainly divided into: thermal energy law (multi-effect distillation, multi-stage flash evaporation, solar distillation, freezing, etc.), chemical (ion exchange method, solvent extraction, hydrate method, chemical precipitation method), electric-membrane (electric to ionic, electroosmosis chromatography), electric adsorption, pressure-film method (multi-stage reverse osmosis, nona) and other 5 types of. The desalting with the chemical method, a low level of salt, those can be removed only poorly soluble substances can be converted into salts, that is, calcium, magnesium, iron, manganese cation of the salt. As for the sodium, potassium, and the like has no cationic salt of. Especially in the ion concentration of chlorine in water is relatively high, the effect of precipitation thereof greatly discounted, large range of application of the constraint; electrical-membrane (electric to ionic, electrodialysis law) adsorption technology such as the initial equipment investment is large, the pre-treatment process is complicated, tedious management and operation, for reverse osmosis concentrated water processing will have a relatively high cost of water; in the thermal energy law , solar distillation, freezing france receives to the natural conditions, evaporation and crystallization rate is relatively low, the industrial field is very difficult to adapt to the requirements of the water treatment. Multi-effect distillation (MED), such as multi-stage flash distillation (MSF) method is to utilize low-grade waste heat in a plurality of ordered arrays of the container, heating and evaporation of the high-concentration saline water steam is generated, steam condensed to obtain the high-quality fresh water. Multi-stage flash distillation (MSF) to take step-down expansion method of flash evaporation of sea water, and the multi-effect distillation (MED) is used for the evaporation of sea water vapor direct heating steam, because the characteristics of the two process, than the progression of the MSF system MED counts of the system. In order to improve the energy utilization rate, reduce the cost, the search for high-efficient heat pump is still not solved.

Pressure-film method (multi-stage reverse osmosis, nona) from the 20 century 70 1990s. since put into application, has been the search for processing condensed water, the method of reducing the associated operating costs, but only depend on the development of multi-stage series of membrane technology to solve the problem of concentrated water is not enough, also need other method the cost is reduced. Unfortunately a large amount of energy used to provide high pressure of the system, and this partial pressure most of the losses are wasted, if in accordance with the usual 40% recovery rate calculation, the concentrated salt water accounts for about 60% of the energy feed pressure. Since there is not yet effective method for treating the concentrated water, the reverse osmosis device increased the cost of water, at the same time waste of a large amount of energy, concentrated salt water pollution to the environment is still the problem of unable to effectively solve the problem.

Content of the invention

The purpose of the invention is to establish a set of reverse osmosis system used for processing of the high-concentrated salt water technique and apparatus, this method mainly utilizes the process of water in the reverse osmosis system of the self-produced form practical knowledge excess pressure high salt water fog, save the conventional atomizing the required power, the flow of fine small drops evaporate rapidly in the air, separation of impurities such as water and the salts, and, at the same time the organic matter contained in the water is oxidized to carbon dioxide, water vapor input condensation as pure water, and salt and the high water concentration of the bottom of the drop in the separating chamber, is mixed with the initial adopts after circulating water, continue to atomizing concentrated to saturation state, through the heat exchanging the salt-containing separation by crystallization after condensation, ultimately achieving reverse osmosis water purification and salinity removing condensed water. The invention changes the existing reverse osmosis operation of the device and its concentrated water treatment method, the cost of water-saving, generated by reverse osmosis can greatly reduce the high concentrated salt water emissions, reduce the concentrated salt water discharged to the peripheral environment of the negative impact caused by, suitable for all kinds of reverse osmosis system for purifying condensed water produced. The technical scheme of the present invention are as follows:

A kind of reverse osmosis practical knowledge -odd pressure spray desalination method, which is characterized in that according to the following steps:

1) the waste water under the high pressure of the reverse osmosis device (1) separating the waste water for the concentrated water;

2) the concentrated water through the heat exchanging system (2) after preheating, through the mixed exchanger (3) directly enters the atomization room (4), the energy of the concentrated water in through the pressure the rotary atomizer, the water in the spray nozzle on the front end of the disc, depending on the high-speed rotation of the disc will be made into a thin film the practical knowledge unfolds , by "centrifugal force spray" and "speed spray" comprehensive effect of the water droplet atomizing;

3) after the atomization the practical knowledge bubble passes through of the temperature control heating system (5) of the contact buckles, forming water vapor and water preparation over into the dense workpiece;

4) by the induced draft fan (7) the water vapor and air flow out of the evaporation chamber into the gas-powder separator (8), entrained in the air are removed salt powder, and then the condensed water collector (9) is condensed into fresh water and so as to be recovered;

5) the tail water entering into the tail water distribution system (11), the salinity and temperature of the on-line monitoring, feedback information: when the tail water salinity to approach or reach the saturation, the collector adopts the tail water of crystallization (10) cooling crystallization, the desalting; adopts the not yet reached saturation, directly flow back to the mixed exchanger (3) after being mixed with the condensed water re-entering the atomization room (4) circulation evaporation;

6) the crystallization is carried out by entering the salt salty dregs tail materialdregs tail material collector (12) centralized processing after storage.

The invention the reverse osmosis practical knowledge -odd pressure spray desalination method, in the step 3) the temperature in the heating system of the hot air from the air blower (6) and is blown in the room, the air source can be air and inferior goods heat steam, operating temperature is 50-100 the [...].

The invention the reverse osmosis practical knowledge -odd pressure spray desalination method, in the step 1) of the waste water in is referred to: industrial waste water, environmental pollution treatment of the waste water, sea water and myoporum saltiest salt water.

The invention the reverse osmosis practical knowledge -odd pressure spray desalination method, in the step 1) of the reverse osmosis device in discharged pressure is 1.5-20 MPa. The invention the reverse osmosis practical knowledge -odd pressure spray desalination method, in the step 1) of the salt in dregs tail material collector (12) is made of corrosion and a polytetrafluoroethylene material processing, collection utility rectangular box structure.

The invention the reverse osmosis practical knowledge -odd pressure spray desalination method for the principle of the invention:

Reverse osmosis system utilizes the high pressure of the water separation for desalting fine water and waste thick salt water (hereinafter referred to as: the concentrated water), wherein the concentrated water from the membrane reactor pressure is as high as 1.5-20 MPa. The invention will be the concentrated water after preheating by the heat exchange system, directly enters the atomization room, the energy of the concentrated water in through the pressure-operated rotary atomizer, concentrated indoor sprays atomized fog-shaped, and spiral track movement. At the same time its atomization is concentrated indoor, the water drops suspended in the air flow to a very small volume, the diameter generally the 100 within   m, specific surface area is very large, the heat transfer with the surrounding air, after the atomization of the contact and wiring terminal practical knowledge bubble , the moisture in the condensed water to evaporate rapidly become water vapor, in the middle part of the concentrated water is oxidized or volatile organic matter, the concentrated water from the concentrated to tail water is high. After the end of the evaporation process, the water vapor by the draft fan and air flow out of the evaporation chamber into the gas-powder separator, entrained in the air are removed salt powder, then through the heat exchange system of the fresh water of condensation and recovery. Concentrated rear tail water entering into the tail water distribution system, the salinity and temperature of the on-line monitoring, feedback information to the intelligent decision-making: when the tail water salinity to approach or reach the saturation, will enter heat exchange system adopts the cooling crystallization, the desalting; adopts the not yet reached saturation, direct return to the mixing exchanger, and the concentrated heat, energy and material content of the mixture, into the atomization room circulation evaporation. In this invention heat the steam by the blower blown into the atomization room, the air source can be air and inferior goods heat steam, generally in the operating temperature of the 50-90 [...] , can also be according to the actual need, in the temperature control heating system is improved in intake air temperature, enhanced oxidizing water desalination and the effect of organic matter.

The invention the reverse osmosis practical knowledge -odd pressure spray desalination method of the detailed steps are as follows:

(1) according to the required evaporation of water, adjusting inflow gas flow rate and temperature, the atomization gas into the room.

The operation carried out mainly in the air circulation system, the air circulation system comprises a blower, a temperature control heater, gas source can be air and the hot steam inferior goods , the composed of a blower and gas enters the temperature control heater, according to the actual situation of the heater, the operating temperature of the inflow gas in general the 50-90 [...] , can also be according to the final processing requirements, the intake air temperature is raised, enhancing desalting efficiency and improve the effect of the oxidation of organic matter in the water mist. After the inflow gas to the temperature required, entering the atomization room, with the induced draft fan in the indoor structure is a whole under suction effect of the circling motion.

(2) the reverse osmosis of discharged concentrated water heat system preheating.

The operation step is carried out in the heat exchange system, the aim is to improve the temperature of the concentrated water when atomized, atomization evaporation time is shortened. The heat exchange system mainly the atomized water steam, the reverse osmosis and after concentrating the heat exchange between the condensed water, the water steam, after concentrating the heat of the concentrated water is transmitted to the reverse osmosis. The exchange of heat between the steam and the condensed water by using embedded steam-water heat exchanger to carry through, after concentrating with concentrated the water depends on the heat-pipe exchanger to achieve heat transfer.

(3) after preheating atomizing the room in the atomization of the condensed water.

The operation of the atomizing concentrating compartment, the concentrated water first enters the pressure the rotary atomizer, through the device, the front end of the disc in the nozzle the practical knowledge gushes in , rely on high-speed rotation of the disc will be made into a thin film the practical knowledge unfolds , by "centrifugal force spray" and "speed spray" comprehensive effect of the water droplet atomizing; the device can make the atomized droplets more narrow particle size distribution, more uniform, when the condensed water using reverse osmosis to produce the excess pressure of the concentrated water into a diameter of 100 the water drops within   m, and the rotating the spray nozzle to spray the same in the gas stream at the top of the concentration chamber, relying on the sprayed water mist suspended in the centrifugal action of a the top of the atomization room of the movement of the airflow in a spiral state, the movement track of the time the water droplet settling process, improving the atomization at the same time evaporating effect of the water globules.

(4) concentrated water atomized droplets contact with inflow air mixing, evaporation and concentration.

In the process for atomizing and concentrating, after the inflow air into the atomizing concentrating, guiding the inner wall under the action of drainage of the fan to Backpitch state flow, and the top of the dense water mist which the movement of the double-spiral flow around the structure, because the atomization of the suspension in the air flow to a very small volume practical knowledge bubble , specific surface area is very large, the inflow air for heat transfer, thus concentrated water most of the moisture to evaporate rapidly become water vapor, forming fine salt particles and adopts high power concentration, particle size minor salt dust floating in the air stream, and after concentrating concentrating fogdrops of formed at the bottom part of the tail water. Furthermore, in the contact process of evaporation of the contained practical knowledge bubble central is oxidation and volatilization of organic matter.

(5) the condensation of the hot steam.

After the end of the evaporation process, the step from an induced draft fan (4) the water vapor and air flow out of the vaporizing chamber in the form of gas-powder separator, through the separator to remove air entrained in the salt material powder, salt and other impurities can be used for keeps out the chamber after being collected, the snow melting in winter, the purified mixed gas to enter the heat exchange system, relying on the embedded heat exchanger for steam and water the gas condensation and reverse osmosis concentrated water preheating, for steam condensation enters the collector shui Dan and recovery, other gas is discharged into the air.

(6) concentration of tail water of regulation and processing.

The process is mainly the control system adopts, the heat exchange system in the mixed exchanger, can be divided into the following three sub-steps:

(1) control of water concentrated workpiece.

Step (4) is high times the drainage to concentrate the water distribution system, the system can be to the tail water concentration and the temperature of the salt in the on-line test and monitoring, according to the system feedback information to intelligent decision-making, according to the tail the temperature of the first decision-making, to assess the condition of the tail water saturation temperature the solubility of the salt, the salt content of the monitoring by a combination of the judge whether the system reached or is close to saturation, when the tail water salinity to approach or reach the saturation, will be deployed to adopts the heat exchange system; the saturation has not been attained, after being mixed directly with the condensed water, to re-enter the atomization room circulation evaporation.

(2) approach or reach saturation condensation of tail water of crystallization.

Saturated adopts are deployed to the heat exchange system, through the heat exchange pipe to reverse osmosis to discharge the initial concentrated water preheating, when the temperature is reduced to the set saturation solubility when the corresponding temperature, will be discharged to the collector adopts a large amount of condensation in the crystallization, the secondary removal of the salt.

(3) non-saturated tail water circulating concentrated

The non-saturated adopts direct reflux to the mixing exchanger, and the condensed water is mixed in the heat exchanger, energy and material content mixed, and then to re-enter the atomization room circulation evaporation.

Reverse osmosis practical knowledge -odd pressure spray desalination effect contrast table 1

The present invention further discloses the reverse osmosis practical knowledge -odd pressure spray desalination method for preparing various types of reverse osmosis system waste thick the application of the salt water, is not influenced by the concentrated water and reverse osmosis device categories of restricted, and can be jointly used with other processing method. Which comprises preparing a separation industrial waste water, environmental pollution treatment of the waste water, sea water and the application of the salt water.

This invention relates to reverse osmosis practical knowledge -odd pressure spray desalination method and the prior art has the technical characteristics and the positive effects:

(1) the excess pressure of concentrated water using reverse osmosis atomized, saving power for atomization, the structure is simple, the manufacturing cost is low.

(2) is not influenced by the concentrated water and reverse osmosis device categories of restricted, processing range is wide, it is easy to realize and the popularization and application, can be conveniently realized with traditional desalination method for coupling, improving the overall economic efficiency of the desalination desalination process.

(3) the device scale flexible, convenient dispersed using, in addition to nozzle components, the operating pressure is mostly atmospheric pressure, generally in the operating temperature of the 50-90 [...] , easy to use low level heat energy as a source of energy, which is cheap and easy to obtain the high-molecular material manufacturing equipment.

(4) the theoretical 99% more concentrated salt water evaporation processing, into the fresh water and concentrated of the discharge amount of the water is quite small, reducing secondary pollution of the environment, the tail water of the salt slurry of outputs can be used in chemical, building materials and other industries.

(5) the gasification process in the gas-liquid interface of the non-equipment wall surface and, therefore, the device the fouling tendency of small, feeding pre-processing requirement is low, the operation is simple, replacement and the maintenance is convenient.