RU2206512C1 - Method of distillation of mineralized water and plant for realization of this method - Google Patents

Abstract

FIELD: distillation of mineralized water by freezing-out; irrigated farming agriculture and agricultural water supply systems. SUBSTANCE: water to be distilled is frozen-on by layers , 5-15 mm thick for forming ice platform, 200-250 mm thick. Mineralized water is delivered by layer of 2500-6000 mm. Ice is frozen-on and thawed through system of vertical cavities provided with shut-off devices in their lower portion. Local zones of non-freezing highly mineralized water are formed in bale body for forming drainage cavities for discharge of brine from ice body. To this end, ice platform having transversal and longitudinal inclination is used with reinforced concrete grate above platform at height of 200-600 mm; reinforced concrete bead is provided over perimeter of platform at height of 2500- 6000 mm ; use is also made of chute, receiving well, venting chambers, receiving pond with supply passage and bottom water outlet , distilled water receiving pond, evaporating pond and pipe line with gate valve, additional pipe line with wells and gate valves, control instruments for check of level of water. EFFECT: increased productivity. 3 cl, 3 dwg

Description

 The invention relates to agriculture, in particular to technologies and technical means for desalination of saline water by freezing using natural climatic factors and intended for irrigated agriculture, industrial and agricultural water supply.

 There is a method of desalination of mineralized water by freezing them naturally in flat pools (maps), which are filled with mineralized water with a layer height of up to 20 cm, ice 1-2 cm thick formed during freezing of water in the pools is cleaved, collected and transported to a room with a positive temperature, then it is desalinated by thawing (see, for example, the article by Puchko V.I. A new way to desalinate water by freezing / Hydrotechnics and Land Reclamation. - 1949. - 3).

 The disadvantages of this method include the high complexity, technical difficulties, the cyclical nature of the operation process, the need to build expensive facilities and low fresh water output. This is proved by the fact that after each chip of ice, mineralized water is released from the pool with a layer of 5 cm and the initial mineralized water to be desalinated is added to it.

There is also known a method of desalination of sea and salt water, including continuous spraying of freezing water, the formation of ice granules with the content of freezing water inside them, the formation of an ice block and obtaining fresh water by thawing ice (SU, copyright certificate 1130531, A, M. cl. ^3. C 02 F 1/22, F 25 C 1/02. Method of desalination of sea and salt water / A. V. Sosnovsky, V. G. Khodakov. Declared 04/08/1982; publ. 12/23/1984, bull. 47).

A known installation for implementing the above method, including desalination ice platforms, a pumping station with a supply pressure pipe, a sprinkler for spraying, a bulk drainage layer, a drainage pipe with a valve, an evaporation pond of desalination brines, a storage pond of saline waters with a bottom outlet and a pit in intake zone pond battery desalinated water (SU, Inventor's certificate 1786005, A1, M. cl. ⁵ C 02 F 1/22. Plant for desalination of saline water / AG Alimov, NE in rlamov, AD Bryzgalin, VE Marinenko, I. KONTOROVICH, RA Balbec Stated 09.11.1989;. published 07.01.1993, Bul 1)...

The disadvantages of the described method and this installation for its implementation include significant costs of material and energy resources. This is due to the fact that continuous spraying of freezing mineralized water requires an expensive installation that is difficult to operate. To implement the method, it is necessary to strictly ensure a certain diameter of the droplets of sprayed water, the magnitude of which depends on many factors, including the height and intensity of dropping drops, the difference between the air temperature and the freezing temperature of mineralized water, wind speed and other conditions. A special limiting condition for the application of this method of winter sprinkling is that the air temperature in winter should not exceed an average of minus 5 ^o C. per day.

 The closest analogue to the claimed object relates to a method of desalination of mineralized water by natural freezing in winter ice riots 275-420 cm thick, ice riots are frozen in succession in small layers of 1-2 cm, when melting from the ice mass, saturated saline solution (brine) first flows and then desalinated water (see MF Mitin, Ya.M. Pashenkov. Desalination of water for agricultural water supply / Bulletin of Agricultural Science. - 1964. - 12. - P.94-100).

 There is also known an installation for implementing this method, including a reinforced concrete platform with a double slope in the transverse and longitudinal directions, above which a horizontal reinforced concrete grille is installed at a height of 15 ... 35 cm, and a reinforced concrete side around a height of 120 cm is made around the site to enhance the air flow under ventilation is installed on the grill along the major axis of the site, which can be adjusted by opening special ventilation chambers, which allows you to partially change the temperature of desalinated ice. Ice freezing is carried out only on top of a reinforced concrete lattice. A collection well is provided for collecting water flow from the site during ice melting (MF Mitin, Ya. M. Pashenkov. Desalination of water for agricultural water supply / Bulletin of Agricultural Science. -1964. - 12. - P.94-100).

 The main disadvantages of this method and installation for its implementation are the uneven distribution of temperature in the thickness of the ice riot during thawing. The highest temperature is set on the surface of the riot, the lowest in the middle. The riot core maintains a relatively low temperature for a long time, thus preventing brine migration. This reduces the yield of fresh water.

 The essence of the claimed invention is as follows.

 The problem to which the claimed invention is directed is to increase the yield of desalinated water from the freezing and thawing ice massif.

 The technical result is an increase in the productivity of the installation by freezing ice and increasing the uniformity of temperature distribution inside the ice block during freezing and thawing during desalination of saline water.

 The specified technical result in terms of the method is achieved by the fact that in the known method of desalination of saline water, including layer-by-layer natural freezing of ice riots in winter and the release of brine from it with the onset of the warm season, according to the invention, desalinated mineralized water is thinned in thin layers of 5-15 mm in in the form of an ice pad 200-250 mm thick, to which mineralized water is supplied with a layer of 2500-6000 mm and ice is frozen and then thawed throughout the water column the intensive air penetration, respectively, with negative and positive temperatures through the system of vertical cavities and under the ice platform, and when the ice riot is formed and its temperature is regulated, local zones from non-freezing highly mineralized water are artificially created for the entire thickness of the ice riot to form drainage cavities for drainage brine from the ice massif.

 The technical result in terms of installation for desalination of mineralized water is achieved by the fact that in a known installation containing reinforced concrete desalination ice with a double slope in the transverse and longitudinal directions, a reinforced concrete grate above the site, a reinforced concrete side around the perimeter of the site, a receiving well and ventilation chambers under the grate, according to According to the invention, it has a mineralized water storage pond with a supply channel and a bottom outlet, a desalinated water storage pond, an evaporation pond and abzhena with a system of vertical cavities with locking devices in their lower part for the penetration of air with negative and positive temperatures, an additional pipeline with wells and valves for the removal of brine into the evaporation pond and desalinated water into the storage pond, a control and measuring system for monitoring the level of water mineralization at the exit from the receiving well, with protective shafts, and the height of the reinforced concrete side along the perimeter of the ice surface is equal to the height of the freezing ice riot within 2500 -6000 mm, while the reinforced concrete grating on the ice platform is located at a height of 200-600 mm.

 The invention is illustrated by drawings.

 Figure 1 shows the technological scheme of the installation of desalination of mineralized water by natural freezing method, plan view; figure 2 is a section aa in figure 1; figure 3 is a section bB in figure 1.

 Information confirming the possibility of implementing the claimed invention are as follows.

The method of desalination of mineralized water by natural freezing is implemented as follows. In the proposed method, when the vertical cavities are hermetically closed from below, it is envisaged that the space under the reinforced concrete grate is filled with mineralized water and ice layers of 200-250 mm thick are frozen in thin layers of 5-15 mm on top of the grate. After that, mineralized water is discharged from under the grate into the evaporation pond, and locking devices are opened in the lower part of the vertical cavities (not shown in the drawings). Then, mineralized water is supplied to the ice platform with a layer of 2500-6000 mm and ice is frozen throughout the water column by penetrating cold air with negative temperature through vertical cavities, ventilation chambers, and under a reinforced concrete grill. When freezing, mineralized water is divided into fresh ice and saturated saline (brine). The desalination process proceeds at a temperature above minus 5 ^o C, while fresh ice crystals at this temperature remain in the solid state, since they melt only at 0 ^o C. Since the specific gravity of the brine is more than ice (600-700 t / m ³ ) then, when melting, first the saturated saline solution flows, and then the desalinated water. By airing the ice riot through airflow through a system of vertical air-conducting cavities, ventilation chambers and the space under the reinforced concrete grill, a uniform temperature distribution is achieved in the thickness of the ice riot. This speeds up the process of brine migration from ice during its thawing, which increases the yield of fresh water.

 Installation for desalination of saline water (see Figs. 1-3) contains a storage pond 1, where mineralized water enters through channel 2 (or a pipeline), a water outlet 3 with a well 4 and a valve 5 in its end part, a structure for freezing and desalination ice 6, a pond-accumulator 7 of desalinated water, an evaporation pond 8 of brines residual from desalination, a pipeline 9 with wells 10 with control valves 11 and a control and measuring complex 12 for monitoring the mineralization of water at the outlet of structure 6, protective shafts 13.

 The complex of facilities for the desalination process of mineralized water by the method of freezing is most advantageously located in a developed ravine-girder network in compliance with the following requirements.

 A storage pond 1 of mineralized, for example, drainage water is located in the upper part of the beam by means of an earthen dam with a bottom outlet 3.

где m₀ - минерализация опресняемой воды, кг/м³;
∑ t - сумма среднесуточных отрицательных температур воздуха за зимний период намораживания бунта льда, ^oС;
k - коэффициент пропорциональности, м⁴ /(кг•^oС).The facility for freezing and desalination of ice 6 is located below the storage pond 1, the size and volume of which should be sufficient to accept the annual volume of the flow of mineralized drainage water accumulated in the storage pond 1. In a structural respect, the structure for freezing and desalinating ice 6 is presented in the form reinforced concrete tank 14, including reinforced concrete platform 15 with a double slope in the transverse and longitudinal directions, a tray 16 and a receiving well 17 for collecting brine and desalinated water. Above the reinforced concrete platform 15 on the supports 18, at a height of 200 ... 600 mm, a reinforced concrete grille 19 is mounted on which reinforced concrete or metal vertical air-conducting cavities 20 with sealed locking devices (not shown) are installed in a checkerboard pattern or in another order the lower part, designed together with ventilation chambers 21 located along the longitudinal axis of the platform 15, to ventilate the ice mass in the process of its formation and subsequent desalination. The distance l (figure 1) between the vertical air-conducting cavities 20 and the dimensions of their transverse square section a (figure 2) are taken based on the following relationships:
l≤a;

where m ₀ - salinity of desalinated water, kg / m ³ ;
∑ t is the sum of daily average negative air temperatures during the winter period of freezing of an ice riot, ^o С;
k is the coefficient of proportionality, m ⁴ / (kg • ^o С).

 The accumulation pond 7 desalinated water is located in the middle of the beam, hollows or in other folds of the area by means of an earthen dam. The pond-accumulator 7 has a sufficient volume to accept the entire volume of desalinated water, flood and storm runoff from the adjacent catchment.

 The evaporation pond 8 is designed to receive and naturally evaporate the residual brine to brine or solid residue during the warm season of the year. This residue is subsequently removed and disposed of. Evaporation pond 8 is a carefully planned area, bunded or covered by an earthen dam in the lower part of the beam (or terrain with a directed slope) and inscribed as much as possible into the relief. The area of the evaporation pond 8 is determined based on the volume of residual brine and the layer of natural annual evaporation of water in a given area.

 For transporting the residual brine from desalination to the evaporation pond 8 and desalinated water to the storage pond 7, a pipeline 9 is provided with wells 10 and control valves 11 located below the freezing depth of the soil in the area, as well as a control and measuring complex 12 for monitoring salinity water at the outlet of the receiving well 17, associated with the actuators of the control valves 11 (communication lines and actuators themselves are not shown in the drawing).

 Barrier shafts 13 are designed to exclude the possibility of flood and storm water entering the construction zone to freeze and desalinate ice 6 and into the evaporation pond 8 and to prevent dilution of the evaporated residual brine and overflow of the evaporation pond 8.

 Installation works as follows.

 Throughout the entire period of the drainage operation (200-250 days a year), the mineralized drainage flow is accumulated in the storage pond 1.

When negative temperatures occur, the mineralized runoff from the storage pond 1 is supplied to a structure for freezing and desalinating ice 6 using a water outlet 3, shut-off devices (not shown) are hermetically closed at the bottom of the vertical air-conducting cavities 20, the space under the reinforced concrete grating 19 is filled with mineralized water, and thin layers of 5-15 mm on top of the grating 19 freeze ice 200-250 mm thick, after which mineralized water is discharged into the pond from under the grating 19 through a receiving well 17 and pipeline 9 the vaporizer 8 and open the locking devices (not shown in the diagram) in the lower part of the vertical air-conducting cavities 20. On the ice platform (200-250 mm), firmly formed on the reinforced concrete grating 19, the storage pond 1 through the outlet 3 serves mineralized water with a layer of 2500- 6000 mm and freezing over the entire water column. Intensive volumetric penetration of cold (frosty) air into the array of freezing mineralized water previously accumulated in the building 6 for freezing and desalinating water is carried out through an active integrated ventilation system, namely through vertical air-conducting cavities 20, ventilation chambers 21 and under the reinforced concrete grille 19, on which freezes riot. When forming an ice mass in building 6 and regulating its temperature using an integrated active ventilation system, between each group of four consecutive adjacent vertical vertical air-conducting cavities 20, ice-free zones (in the form of cylinders with a diameter of 20-100 mm) are artificially frozen over the entire thickness of the ice riot water, after discharge, which into the pond-evaporator 8 in the ice riot formed drainage cavities, significantly accelerating the process of removal of the internal brine from the ice mass At low temperatures. Upon completion of the formation of the ice riot during melting, a brine flows out from the mass of ice, the density of which is higher than the density of the initial mineralized water, and then desalinated water. In the process of ice desalination, an ice riot is ventilated through a system of vertical air-conducting cavities 20, ventilation chambers 21 and under a reinforced concrete grill 19 located under an array of frozen ice, and this ensures uniform temperature distribution in the thickness of the ice riot, which accelerates the process of removal of residual brine from ice when thawing it. All this in general increases the yield of desalinated water. To maintain the temperature of the ice mass for a longer time at the level of 0 ... minus 5 ^o C, which provides optimal conditions for the flow of internal brine, the ice mass is covered with a layer of "dry" snow (5-30 cm), which is applied naturally (upon precipitation) snow after the formation of the ice massif) or by artificial spraying. If necessary, shelter ice in the spring with a heat-insulating material. The brine flowing out of the ice mass is collected and discharged along the tray 16 through the receiving well 17 and the pipe 9 into the evaporation pond 8. The residual brine accumulated in the evaporation pond 8 is evaporated to a saturated brine (brine) or a dense residue, which is used for special purposes . In the absence of a regular consumer, salt or brine is accumulated over 45-50 years (the life of the complex), followed by burial or processing using special technology. The volume W of the evaporation pond 8 in this case should correspond to the condition W> W ₀ , where W ₀ is the total residual volume of brine or salts from the evaporation of brines, accumulating over 45-50 years of operation of the desalination complex. Desalinated melt water of permissible mineralization is diverted in the same way to the deserted pond 7 desalinated water. Changing the direction of water disposal is carried out in manual or automatic mode using control valves 11 located on the pipeline 9, taking into account the data of the control and measuring complex 12 for monitoring the level of water mineralization at the outlet of the receiving well 17 of structure 6 for freezing and desalinating ice.

 After emptying the storage pond 1 from the saline drainage water as a result of their winter freezing, the spring flood flood is accumulated into the storage pond 1, which is then discharged through the outlet 3 into the storage pond 7 desalinated water to dilute them to the permissible mineralization.

 Prior to discharge of the flood discharge into the storage pond 7, mineralized water does not enter the storage pond 1 (it is temporarily accumulated in an additional pool (not shown).

 With insufficient flood flow, the dilution of desalinated water to an acceptable mineralization is carried out by additional supply of the required amount of irrigation water through a special channel (not shown) to the storage pond 7.

 Desalinated drainage and spring flood, accumulated in accumulator pond 7, are used in the summer-autumn period for irrigation of crops, gardens, forest stands, agricultural water supply, etc. Water is taken for this purpose from accumulator pond 7 using compact pumping stations (PS) operating from wind power plants - wind turbines (PS and wind turbines - not shown).

 Thus, intensive volumetric penetration of air with negative temperature into the massif of freezing mineralized waters and subsequent ventilation of the formed ice riot through a system of vertical air-conducting cavities, ventilation chambers, and under a reinforced concrete grill increase the productivity of ice freezing and increase the uniformity of temperature distribution inside the ice block during freezing and defrosting and, as a result, increasing the yield of desalinated water and ice block.

Claims (2)

 1. The method of desalination of mineralized water, including a layer-by-layer natural freezing of ice riots in the winter and the release of brine from it with the onset of the warm season, characterized in that the desalinated mineralized water is frozen in thin layers of 5-15 mm in the form of an ice pad 200-250 mm thick to which mineralized water is supplied with a layer of 2500-6000 mm and ice is frozen and then thawed through intensive air penetration throughout the entire water column, respectively, with a negative and second positive temperature through a system of vertical cavities and under ice platform, wherein when forming ice riot and regulating its temperature, artificially create the entire thickness of the ice riot local zones of unfrozen highly mineralized water to form drainage voids for drainage of brine from the ice array.  2. Installation for desalination of mineralized waters, including reinforced concrete desalination ice with a double slope in the transverse and longitudinal directions, a reinforced concrete grate above the site, a reinforced concrete side along the perimeter of the site, a receiving well and ventilation chambers under the grate, characterized in that it has a saline pond water with a feed channel and a bottom outlet, a deserted water storage pond, an evaporation pond and is equipped with a system of vertical cavities with shut-off devices in the lower their parts for the penetration of air with negative and positive temperatures, an additional pipeline with wells and valves for discharging brine into the evaporation pond and desalinated water into the storage pond, a control and measuring complex for tracking the level of water mineralization at the outlet of the receiving well, protective shafts moreover, the height of the reinforced concrete rim around the ice platform is equal to the height of the frozen ice riot in the range of 2500-6000 mm, while the reinforced concrete grate on the ice platform is located at a height 200-600 mm.

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