DESCRIPTION

Field of the invention

[001] The present invention relates to brine recycling plants.

Background of the invention

[002] Brine is a high-concentration solution of salt (NaCl) in water (H2O). It is also a byproduct of many industrial processes, such as desalination, so it requires wastewater treatment for proper disposal or further utilization (fresh water recovery). Brine is also a byproduct of following industrial processes: power plant cooling, oil and natural gas extraction, acid mine or acid rock drainage, reverse osmosis reject, chloralkali wastewater treatment, pulp and paper mill effluent, and waste streams from food and beverage processing.

[003] Technologies for treatment of polluted brine include: membrane filtration processes, such as reverse osmosis and forward osmosis; ion exchange processes such as electrodialysis or weak acid cation exchange; or evaporation processes, such as thermal brine concentrators and crystallizers employing mechanical vapour recompression and steam.

[004] Aforementioned technologies are disclosed in Russian patent publications Nos. RU2603799 and RU2613920, as well as in U.S. patent application publication No. US2011198208 and Australian patent application publication No. AU2018383041. Water desalination plants using renewable energy sources are disclosed in Utility model registration publications Nos. CN204625232U and CN204661346U.

[005] Aim of the invention is to design a brine recycling plant having effective desalination process, zero CO2 emission, as well as having zero return. The zero return means that no processed brine is discharged from the brine recycling plant back into the environment. Summary of the invention

[006] The aim is reached by design of a new brine recycling plant which only and fully utilizes renewable energy as an energy source for brine recycling. The brine recycling plant comprises a brine tank, a condenser fluidly connected to the brine tank, a solar heat collector configured to heat a heat transfer fluid within the collector, a heat exchanger configured to transfer a heat generated by the solar heat collector to the brine, a water pool configured to evaporate a water from the brine into a steam. The steam is then further transferred to the aforementioned condenser where the stem condenses into the water and that water is further transferred to a clean water tank. The plant further comprises a dehydrator configured to extract solid particles from the brine which was not evaporated with the water pool. Moreover, the brine processed through the dehydrator is returned to the brine tank for repeated recycling within the plant. Hence, zero return or waste brine recycling is provided.

[007] The brine tank may be any tank or container capable to hold the brine. It is advantageously to use a brine tank is black colour as it initially will warm up the brine during the day.

[008] A condenser comprises a sealed vessel and a pipe coil enclosed by the sealed vessel. The sealed vessel and the pipe coils are separated or sealed from each other so that the brine within the pipe coil cannot mix with the steam entering a sealed vessel and the water condensed from the steam. The sealed vessel comprises an inlet which is fluidly connected to the water pool for receipt of the steam generated within the water pool and an outlet which is fluidly connected to the clean water tank for discharge of the condensed water to the clean water tank. The pipe coil within the sealed vessel comprises an inlet which is fluidly connected to the brine tank and an outlet which is fluidly connected to a brine pipe circuit. The condenser works as a heat exchanger and as a condenser simultaneously. The stem from the water pool is condensed into the clean water and the brine within the pipe coil is heated- up from the heat energy of the stem. This synergy of dual technical effect significantly increases overall effectiveness of the plant.

[009] The solar heat collector may be a series of parabolic cylindrical reflectors. The reflectors may be arranged in parallel and in series The parabolic cylindrical reflector reflects the solar radiation and concentrates it on an absorber tube which is part of the collector pipe circuit. In other words, the collector pipe circuit passes along a focal point of the reflector. The medium within the collector pipe circuit is heated up and transferred to the heat exchanger. The medium itself may be a distilled water, oil, or combination thereof. The combination of oil and water involves two separate circuits within the collector pipe circuit.

[010] The heat exchanger comprises a first side for a collector pipe circuit and a second side for a brine pipe circuit. The heat exchanger is configured so that the heat from the first side can be transferred to the second side, therefor transferring the heat from collector pipe circuit to the brine pipe circuit heating up the brine within said brine pipe circuit. Heated brine is further discharged into the water pool for evaporation.

[Oi l] The water pool comprises a base and side walls for containing the brine. The brine pipe circuit is fluidly connected to the water pool so that the brine after flowing through the heat exchanger enters the water pool. The water pool also comprises a double wall cover covering an upper side of the water pool so that the water pool is fully enclosed or sealed further facilitating evaporation of the brine within the water pool. The double wall cover is made from transparent material, especially from the material that is transparent in the range of visible light and near infrared range. Vacuum is formed in a space between the two walls of the double wall cover. The base of the water pool is inclined so that the brine entering the water pool due to gravitational forces flows to the opposite side of the water pool for discharge from the water pool and to the dehydrator. The water pool comprises a steam outlet fluidly connected to the inlet of the sealed vessel of the condenser, through which a steam generated from the brine within the water pool is transferred to the heat exchanger.

[012] The dehydrator comprises a stirring unit configured to stir the incoming brine from the water pool. The stirring does not allow sedition of salt within the brine. The dehydrator comprises a salt extraction unit fluidly connected to the stirring unit so that the brine can be further processed in the salt extraction unit. The salt extraction unit comprises a screw conveyor configured to transfer the brine out from the brine pool of the salt extraction unit and the excess brine on the screw conveyor drips and the salt left on the surfaces of the screw conveyor is transferred further for off-loading said collected salt. The salt extraction unit of the dehydrator is fluidly connected to the brine tank so that the leftover or non-processed brine within the brine pool is transferred to the brine tank for repeated recycling, in result of which the brine recycling plant is able to provide zero waste desalination or recycling. The present invention is described with an example on salt extraction. Instead of salt other similar minerals or particles as suspension in the water may be extracted.

[013] Aforementioned invention uses only solar energy completely elimination CO2 emissions into the atmosphere. No processed brine is discharged back into the environment - into the sea or into the ground. The plant self sufficient zero waste or zero return brine recycling plant.

[014] The present invention may be used for extracting salts, as well as metals and minerals and other particle matter out of the brine.

Brief description of the drawings

[015] The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments of the invention.

[016] Fig. 1 is a detailed diagram of the layout of a brine recycling plant.

[017] Fig. 2 is a schematic view of an evaporation water pool (50).

[018] Fig. 3 is a schematic view of a dehydrator (70).

Detailed description of the embodiments

[019] The preferred embodiments of the invention are now described with reference to the figures to illustrate objectives, advantages, and efficiency of the present invention.

[020] The brine tank (10) comprises an outlet (11) and inlet (12). The brine tank (10) itself may be in black colour in order to heat up under the sun during the day. Hence, the brine is at least warmed by some degree to ease further heating of the brine within the brine recycling plant (see Fig. 1).

[021] The condenser (20) comprising a sealed vessel (21) and a pipe coil (22) enclosed by the vessel (21). The sealed vessel (21) comprises an inlet (23) and an outlet (24). The pipe coil (22) comprises its own inlet (25) and an outlet (26). The inlet (25) of the pipe coil (22) is fluidly connected to the outlet (11) of the brine tank (10) so that the brine can flow from the brine tank (10) via the pipe coil (22) through the condenser (20). This design of the condenser (20) provides dual function - it heats up the brine that flows through the pipe coil (22) in the condenser and it condenses the steam (27) received from the water pool (50) through the inlet (23) of the sealed vessel (21) into a water (28). The heated-up brine further flows to the heat exchanger (40) (see Fig. 1).

[022] The heat exchanger (40) comprises a first side (41) for a collector pipe circuit (31) and a second side (42) for a brine pipe circuit (43). The heat exchanger (40) is configured so that the heat from the first side (41) can be transferred to the second side (42) therefor heating up the brine within the brine pipe circuit (43) even further to about 110 degrees Celsius (see Fig- 1).

[023] The brine recycling plant comprises a solar heat collector (30) or an array of solar heat collectors (30). The solar heat collector (30) comprises a collector pipe circuit (31). The solar heat collector (30) is configured to concentrate a solar radiation (100) onto the collector pipe circuit (31) to heat up a medium within the collector pipe circuit (31). The medium as a heat transfer fluid is distilled water. Any other fluid may be used which has the heat transfer fluid properties (see Fig. 1).

[024] Upon start-up of the brine recycling plant the valve (44) to the water pool (50) is closed and the brine circulates within the brine pipe circuit (43) and through the second side (42) of the heat exchanger (40) until the brine heats-up to the predetermined temperature of 110 degrees Celsius. When the brine heats-up to 110 degrees Celsius, the valve (44) opens, and the heated brain may flow to the water pool (50) (see Fig. 1).

[025] The water pool (50) has a base (51) and side walls (52) for containing the brine (57). The brine pipe circuit (43) is fluidly connected to the water pool (50) through the inlet (56) of the water pool (50) so that the brine from the brine pipe circuit (43) enters the water pool (50). The water pool (50) comprises a double wall cover (53) covering an upper side of the water pool (50) so that the water pool (50) is fully enclosed further facilitating evaporation of the brine (57) into the steam (27) within the water pool (50). The water pool (50) further comprises a steam outlet (54) fluidly connected to the inlet (23) of the sealed vessel (21) of the condenser (20) so that the steam (27) is drafted into the condense (20) where the steam (27) condenses into the water (28) (see Figs. 1 and 2).

[026] The clean water tank (60) comprises an inlet (61) fluidly connected to the outlet (25) of the sealed vessel (21) of the condenser (20) so that the water (28) condensed from the steam (27) within the condenser (20) flows into the clean water tank (60) (see Fig. 1).

[027] The base (51) of the water pool (50) is inclined so that the brine (57) entering the water pool (50) flows to the opposite side of the water pool (50) due to gravitation. The inclination is 24 degrees but may be varied according to the adjusted power of the plant.

[028] The water pool (50) comprises a brine outlet (55) so that the brine (57), which is not transferred into the steam (27) exits the water pool (50) through the brine outlet (55) of the water pool (50) and further flows into the dehydrator (70) through an inlet (78) of the dehydrator (70) (see Figs. 1 and 2).

[029] The dehydrator (70) comprises a stirring unit (71) configured to stir the incoming brine from the water pool (50). The dehydrator (70) comprises a salt extraction unit (72) fluidly connected to the stirring unit (71) so that the brine can be further processed in the salt extraction unit (72). The salt extraction unit (72) comprises a screw conveyor (73) configured to transfer the brine out from the brine pool (74) of the salt extraction unit (72) and the excess brine (75) can drip and the salt (76) left on the surfaces of the screw conveyor (73) is transferred further for off-loading said collected salt (76). The surface area of the screw conveyor (73) is formed so that the excess brine (75) drips or evaporates and leftover salt (76) encloses within the screw conveyor (73) and is transferred further for off-loading. Offloading is performed with mechanical means so that the salt (76) is removed from the screw conveyor (73). The screw conveyor (73) is rotated be means of a motor (77) connected thereto. The salt extraction unit (72) of the dehydrator (70) through its outlet (79) is fluidly connected to the inlet (12) of the brine tank (10) so that the leftover brine is transferred the brine tank (10) for repeated desalination or recycling, in result of which the brine recycling plant is able to provide zero waste desalination or recycling (see Figs. 1 and 3).

[025] While the invention may be susceptible to various modifications and alternative forms, specific embodiments of which have been shown by way of example in the figures and have been described in detail herein, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the following claims.

[026] List of references

10 - a brine tank;

11 - an outlet of a brine tank;

12 - an inlet of a brine tank;

20 - a condenser;

21 - a sealed vessel;

22 - a pipe coil;

23 - an inlet of a sealed vessel;

24 - an outlet of a sealed vessel;

25 - an inlet of a pipe coil;

26 - an outlet of a pipe coil;

27 - a steam;

28 - a water;

30 - a solar heat collector;

31 - a collector pipe circuit;

40 - a heat exchanger

41 - a first side of a heat exchanger;

42 - a second side of a heat exchanger;

43 - a brine pipe circuit;

44 - a valve;

50 - a water pool;

51 - a base of a water pool;

52 - a side wall of a water pool;

53 - a double wall cover;

54 - a steam outlet of a water pool;

55 - a brine outlet of a water pool;

57 - a brine;

60 - a clean water tank;

61 - an inlet of a clean water tank; - a dehydrator; - a stirring unit; - a salt extraction unit; - a screw conveyor; - a brine pool; - an excess brine; - a salt; - a motor; - an inlet of a dehydrator; and - a solar radiation.