RU2711357C1 - System of water purification by recrystallisation and heat exchange device for system - Google Patents

Abstract

FIELD: water treatment.SUBSTANCE: group of inventions relates to a system for cleaning contaminated and sea water by recrystallisation and a heat exchange device, and can also be used in household, food industry, public catering enterprises and medicine. System consists of at least two heat exchange devices comprising chambers for freezing water and thawing ice and cooling and heating elements, a water circulation circuit, a coolant circulation circuit, connected to cooling and heating elements with possibility of alternating freezing of water and ice thawing in chambers of heat exchange devices and heat transfer of coolant formed in the chamber during freezing of water, into the ice thawing chamber, and control and monitoring means. Heat exchange devices are arranged cascade one under the other and consist of external and internal housings and cylindrical partitions located coaxially relative to each other with formation of annular cavity between their walls, collector for air supply, cooling and heating elements, a heating element fixed in the upper part of the inner housing, and at least one drain pipe. Outer housing is cylindrical or truncated cone shaped upward. External housing is made with additional inner wall, shape and height of which correspond to external housing, and cooling and heating elements are located between said walls. Partition and internal wall of housing are made with possibility of connection to current source.EFFECT: technical result achieved using the group of inventions is high efficiency and high quality of water treatment, which makes it possible to use it for treatment of source water with a wide range of contaminants with organic and inorganic substances.10 cl, 3 dwg, 1 ex

Description

The invention relates to water purification systems and the heat exchange devices used in them, in particular to systems with two- and multi-stage recrystallization schemes, and can be used in everyday life, food industry, catering and in medicine for the treatment of contaminated and sea water.

A known system of water purification by recrystallization and a heat transfer device for its implementation (patent No. EA 024321, IPC-2006.01 C02F 1/22, publication date 05/29/2015), consisting of two heat exchange devices containing one chamber for freezing water and thawing ice, a water circulation loop connected to chambers of heat exchangers, a means for freezing water and thawing ice, and a control and monitoring means. The water circulation circuit contains means for supplying raw water with a hydraulic pump, means for draining the contaminated water concentrate, means for draining clean water, containers for contaminated water concentrate, containers for pure water, means for supplying pure water to the consumer, and means for draining unused pure water . The water circulation circuit is connected to the chambers of heat exchangers with the possibility of purifying water in one recrystallization cycle in each chamber. Heat exchangers are made in the form of a rectangular parallelepiped with a flat slotted chamber. Means for freezing water and thawing ice are made in the form of cooling and heating thermocouples mounted on the outer surface of heat exchangers. The control and monitoring tool comprises a control panel with a microprocessor and associated control boards, control valves and water level sensors. The control and monitoring means is capable of simultaneously freezing water and thawing ice in the chambers of heat exchange devices. The system is intended for use in everyday life, food industry and medicine.

The disadvantages of the known system are:

- relatively high costs of water purification, due to unproductive losses of thermal energy released during freezing of water and thawing ice in the chambers of heat exchangers;

- a relatively long duration of the water treatment process and, accordingly, low productivity due to the use of heat exchangers, in which when freezing the source water there are practically no convective processes that reduce the duration of ice formation while improving the quality of frozen ice;

- a relatively low quality of water purification, due to receiving it in one recrystallization cycle in each chamber, in which heavy water (D ₂ O) and some fine suspensions and impurities are not removed from the purified water.

The above disadvantages limit the functionality of the system.

A known water purification system by recrystallization (patent No. WO 2015111405, IPC-2006.01 C02F 1/22, B01D 9/04, F25B 1/00, F25B 40/04, publication date 07/30/2015), consisting of two heat exchange devices containing two chambers for freezing water and thawing ice and cooling and heating elements, a water circulation circuit connected to chambers of heat exchangers with the possibility of draining pre-treated water from one chamber and supplying it for final purification to another chamber, a refrigerant circulation circuit connected to cooling and n heating elements with the possibility of alternately freezing water and thawing ice in the chambers of heat exchangers and transferring the heat of the refrigerant generated in the chamber during freezing of water to the chamber for thawing ice, and control and monitoring means connected to these circuits with the possibility of changing the direction of water and refrigerant flows in alternate modes of freezing water and thawing ice. The water circulation circuit contains means for supplying raw water, means for draining the contaminated water concentrate, means for draining clean water, a container for contaminated water concentrate, a tank for pure water, and a pump for supplying pure water to said container. The refrigerant circuit contains a compressor, at least one water-cooled condenser, connected in heat exchange with a container for contaminated water concentrate after it is drained from the chambers of heat exchangers, at least two heat exchangers, a refrigerant filter and an expansion valve connected to the inlets and outputs of cooling and heating elements. The control and monitoring means comprises a controller and associated control valves for changing the direction of flow of water and refrigerant in said circuits.

The disadvantages of the known system are:

- complex constructive implementation of the water circulation circuit, due to the use of heat exchangers with two chambers, which necessitates means for forced water circulation, regulating the pressure in the circuit and parallel feeding into the chambers and draining from the chambers;

- a relatively low quality of water treatment due to the receipt of clean water without the allocation of heavy water from it.

The above disadvantages limit the functionality of the system and increase the cost of its operation with a relatively low quality of water treatment.

Known heat exchange device for water purification by recrystallization (patent No. EA 017783, IPC-2006.01 C02F 1/22, publication date 01/30/2013), consisting of a housing with a chamber for freezing water and thawing ice, means for mixing water, a drain pipe, cooling and heating elements and a heat insulating coating. Cooling and heating elements are mounted on the outer surface of the housing, and are made, respectively, in the form of an evaporator and in the form of an electric heater. The mentioned elements are covered with a heat insulating coating. A pipe for draining water is located on the wall in the lower part of the housing. Means for mixing water is made in the form of a water pump or the blades of a mechanical stirrer mounted in the center of the bottom. In the water purification system, the heat exchanger operates alternately in the freezing mode of the source water with the formation of pure wall ice on the inner surface of the casing and in the mode of ice thawing with the discharge of the pure water formed through the pipe. A means for mixing water is used in the freezing mode of the source water after the formation of a thin layer of ice on the walls of the casing to increase the intensity of water cooling and accelerate the process of ice formation. Stirring the source water also helps to remove air bubbles and particles of impurities sorbed from them on the ice surface, to remove impurities dissolved in water from the phase boundary, and to increase the heat transfer intensity inside the casing.

A disadvantage of the known technical solution is the long duration of the water treatment process and, accordingly, the low productivity of the heat exchanger, due to the insufficiently rational geometry of the chamber, which is why ice formation occurs in the freezing mode not only on the surface of the casing, but also in the volume of the source water As a result, the energy transfer from the walls of the casing to the volume of water slows down in proportion to the increase in the thickness of the frozen ice layer. In addition, as the thickness of the ice on the surface of the hull increases, the intensity of the process of displacing impurities at the ice-water interface decreases, which reduces the quality of water treatment.

Known heat exchange device (options) for water purification by recrystallization (patent No. EA 025716, IPC-2006.01 C02F 1/22, C02F 9/02, C02F 103/04, publication date 01/30/2017), consisting of external and internal buildings and cooling and heating elements fixed to the outer case from the outside. The outer casing is made with the possibility of tight locking the lid. In one embodiment, the outer and inner bodies are cylindrical in shape, and in the other, both bodies are made in the form of a truncated cone oriented upward by the angle of the solution. In both versions, the inner case is located in the outer case along its longitudinal axis with the formation of an annular chamber between their walls. The inner cylindrical body is made with closed ends and mounted on a vertical rack with the formation of a gap between its lower end and the bottom of the outer case. The truncated cone-shaped inner casing is made with closed ends and fixed to the lid to form a gap between its lower end and the bottom of the outer casing. The latter is made domed with a decrease from the walls to the center where the drain pipe is located. The cooling element is made in the form of an evaporator, and the heating element is made in the form of an electric heater. The mentioned elements are fixed on the outer surface of the outer casing and are covered with a layer of thermal insulation.

In the water treatment system, the heat exchanger operates alternately in the freezing mode of the source water with the formation of pure wall ice on the inner surface of the outer casing and in the ice thawing mode with the discharge of pure water formed. The presence of an annular chamber makes it possible to narrow the zone of formation of the crystallization front of the source water in the water freezing mode and reduce the duration of this mode. The implementation of the outer casing in the form of a truncated cone, oriented upward by the angle of the solution, further increases the efficiency of heat transfer processes and provides a more tight contact of the ice layer with the inner surface of the outer casing in the ice thawing mode, which improves the performance of the device and the quality of purified water. The above-mentioned design features of heat-exchanging devices allowed to increase their productivity by an average of 25% compared with the device according to patent No. EA 017783 with approximately the same percentage yield of purified water and its quality.

The disadvantage of heat exchangers according to patent No. EA 025716 is the relatively long duration of the water treatment process and, accordingly, low productivity, due to the fact that in the freezing mode in the annular chamber there are practically no convective processes in water. Moreover, the duration of the thawing mode does not change significantly compared to the device according to patent No. EA 017783. In addition, the absence of convective processes in contaminated water significantly reduces the quality of ice frozen on the wall of the outer casing, and, accordingly, the quality of purified melt water.

The basis of the claimed invention is the task of improving the water purification system by recrystallization due to the different design of heat exchangers and associated water and refrigerant circuits and control and monitoring means that provide enhanced functionality and increased productivity at a relatively low cost of operation.

The technical result from the implementation of the task is to significantly reduce the duration of the modes of freezing the source water and thawing ice due to the different arrangement of the heat exchange devices in the system, the different design of the chambers in them for freezing water and thawing ice and their other connection with the water and refrigerant circuits and means management and control. The specified technical result is achieved while significantly simplifying the water circulation circuit, improving the quality of water treatment and reducing operating costs for water treatment. In general, the claimed technical result allows to expand the functionality of the system.

The problem is solved in that in a water purification system by recrystallization, consisting of at least two heat exchangers, containing chambers for freezing water and thawing ice and cooling and heating elements, a water circulation circuit connected to chambers of heat exchangers with the possibility of draining previously cleaned water from one chamber and supplying it for final purification to another chamber, a refrigerant circuit, connected to cooling and heating elements with possible the possibility of alternately freezing water and thawing ice in the chambers of heat exchangers and transferring heat of the refrigerant generated in the chamber during freezing water to the chamber for thawing ice, and control and monitoring means connected to the above-mentioned circuits with the possibility of changing the direction of water and refrigerant flows in alternating modes freezing water and thawing ice, while the water circuit contains a means for supplying source water, a means for draining a concentrate of contaminated water, a means for draining pre-purified water, a means for draining clean water, a container for clean water and a container for a contaminated water concentrate, and the refrigerant circuit contains a compressor, a water-cooled condenser associated with heat exchange with a container for a contaminated water concentrate after it is drained from the chambers of heat exchangers and two heat exchangers, according to the invention, the heat exchangers are cascaded one above the other and contain one chamber, made with the possibility of its division into communicating with each other water to the cooling and recirculation cavities, water circulation between the said cavities and the formation of equipotential surfaces in the cooling cavity when water is frozen, the refrigerant circuit contains an additional air-cooled condenser connected at the inlet and at the outlet respectively to the compressor outlet and to the water-cooled condenser inlet, wherein the first heat exchanger at the input is connected to the inputs and outputs of the cooling and heating elements, and at the output it is connected to the input of the second a heat exchanger, the output of which is connected through heat exchange with a clean water tank and connected to the compressor inlet, the chamber of the upper heat exchanger at the inlet is connected to the source water supply means and at the outlet is connected to the means for draining the contaminated water concentrate and the means for draining the previously purified water, and the chamber of the lower heat exchanger at the inlet is connected to the means for draining the pre-purified water from the chamber of the upper heat exchanger and at the outlet is connected to the means for I drain the concentrate of contaminated water and a means to drain clean water.

Preferably, the control and monitoring means has the additional possibility of separating the source water in the chamber of the upper heat exchanger into heavy and light water, while the heavy water is removed by means for draining the contaminated water concentrate, and the light water is supplied to the chamber of the lower heat exchanger by means to drain pre-treated water.

It is also preferred that the control and monitoring means comprise a controller and associated control valves mounted in the water and refrigerant circuits, temperature sensors mounted on the inlets and outlets of the cooling and heating elements and inside the clean water tank, and a water level sensor mounted inside the tank for clean water, while the control valves were made in the form of solenoid valves for water and refrigerant.

It is also preferable that the system was made with a heat exchange battery connected in heat exchange with the source water along the chamber of the upper heat exchanger and with a concentrate of contaminated water and clean water along their path from the chamber of the lower heat exchanger, and the condenser with water cooling is additionally connected through heat exchange with clean water along the way from the heat exchange battery.

It is also preferable that the means for supplying the source water comprise, along the chamber of the upper heat exchanger, a heat exchange element located in the heat accumulator and a coarse filter, the means for draining the contaminated water concentrate contains a container for the contaminated water concentrate along the chamber of the upper heat exchanger, connected by heat exchange with a water-cooled condenser, and a pipe for draining into the sewer, a means for draining a concentrate of contaminated water and a means for draining True water was made with a common exit from the chamber of the lower heat exchanger and contained along the aforementioned chamber a common heat exchange element in the heat exchange battery, and further along the contaminated water concentrate, they contained the mentioned container for the contaminated water concentrate and a pipe for draining into the sewer, and along the way clean water contained a second heat exchange element located in a water-cooled condenser, a fine filter and a bactericidal lamp, and the clean water tank contained a shut-off valve l to regulate the supply of water to the consumer.

The problem is solved in that a heat exchange device for implementing the system, consisting of an external housing and an internal housing located in the external housing along its longitudinal axis with the formation of a chamber between their walls, and cooling and heating elements mounted on the external housing, while the internal housing made with closed ends, and the outer casing contains at least one drain pipe and is made with thermal insulation of the outer surface and with the possibility of locking the lid, according to the invention The ju further comprises a cylindrical baffle fixed in the said chamber with the formation of cooling and recirculation cavities, respectively, communicating with each other through water under and above the baffle, a heating element and air supply means, while the inner casing is cylindrical, the baffle is aligned with external and internal cases, the means for supplying air is mounted on the bottom of the external case in the cooling cavity, and the heating element is fixed in the upper parts of the inner case.

Preferably, in the heat exchanger, the outer casing is cylindrical.

Preferably, in the heat exchange device, the outer casing is made in the form of a truncated cone, oriented upward by the angle of the solution.

It is also preferable that in the heat exchanger the outer casing is made with an additional inner wall, the shape and height of which correspond to the outer casing, cooling and heating elements are located between the walls, and the height of the partition is 0.8-0.9 of the height of the outer casing.

It is also preferable that the partition and the inner wall of the housing are configured to be connected to a current source.

The improved design of the water purification method by recrystallization ensures the achievement of the claimed technical result. In particular, the arrangement of heat exchangers in a cascade one under the other and their implementation with one chamber for freezing water and thawing ice can significantly simplify the circuit of the water circulation compared to the known technical solution by eliminating the means for forced circulation and parallel connection of the chambers. The implementation of the chambers with the possibility of separation of water into interconnected cooling and recirculation cavities and with the possibility of water circulation between the said cavities can increase the intensity of convective processes in the freezing mode and at the same time improve the quality of ice on the inner surface of the casing and, accordingly, improve the quality of purified water obtained in the result of its thawing. In addition, the implementation of the chambers with the possibility of separating water into interconnected cooling and recirculation cavities allows to narrow the zone of formation of the annular front of crystallization of water and thereby reduce the duration of the freezing mode. The possibility of the formation of equipotential surfaces in the cooling cavity allows the use of an additional electrolysis effect when freezing water, and thereby significantly improve the quality of ice. The implementation of the refrigerant circulation circuit with additional air-cooled condenser and new interconnections of heat exchangers is aimed at implementing the inventive system and at the same time reduce the unproductive losses of thermal energy released during freezing and thawing ice in the chambers of heat exchangers, and, accordingly, reduce operating costs for water treatment .

The improved design of the heat exchange device ensures the achievement of the claimed technical result. In particular, the implementation of the annular chamber with a cylindrical septum fixed with the formation of cooling and recirculation cavities communicating with each other through water under the septum and above it, improves the efficiency of energy transfer from the walls of the outer casing to the volume of water, which reduces the duration of the freezing mode. At the same time, this allows to increase the volume of the external casing and, accordingly, the volume of clean water output per one cleaning cycle. The use of a heating element fixed in the upper part of the inner casing and a collector for supplying air mounted on the bottom of the outer casing in the cooling cavity makes it possible to increase the intensity of convective processes in water and thereby further reduce the duration of the ice formation process. At the same time, an increase in the intensity of convective processes simultaneously improves the quality of ice on the inner surface of the outer casing and, accordingly, the quality of purified water obtained by thawing such ice.

A schematic representation of a water purification system by recrystallization and design options for a heat exchange device is shown in the figures of the drawings, where in FIG. 1 shows a schematic diagram of a system; in FIG. 2 is a diagram of a heat exchange device with an external cylindrical body (option 1); in FIG. 3 is a diagram of a heat exchanger with an outer casing in the form of a truncated cone, oriented upward by the angle of the solution (option 2).

The system consists (Fig. 1) of the upper 1 and lower 2 heat exchangers arranged in a cascade relative to each other, a water circuit 3 (shown by solid thick lines), a refrigerant circuit 4 (shown by solid thin lines) and control and monitoring 5 ( shown by dashed lines).

Heat exchangers 1 and 2 (shown schematically) contain, respectively, chambers 6 and 7 for alternately freezing water and thawing ice and cooling and heating elements 8 and 9.

The water circulation circuit 3 contains means for supplying source water to the chamber 6, means for draining the contaminated water concentrate from the chambers 6 and 7, means for draining the pre-treated water from the chamber 6 into the chamber 7, means for draining the contaminated water concentrate from the chambers 6 and 7 , a means for draining clean water from the chamber 7 and a container 10 for clean water. The said means are made in the form of pipe sections (not indicated) with devices mounted on them. The means for supplying the source water to the chamber 6 contains a bactericidal lamp 11 and a coarse filter 12. The means for draining the contaminated water concentrate from the chambers 6 and 7 contains a container 13 for the contaminated water concentrate connected through heat exchange with the refrigerant circuit 4, and a pipe 14 for draining into the sewer. The means for draining the pre-treated water from the chamber 6 into the chamber 7 is made in the form of a branch from the means for draining the contaminated water concentrate from the chamber 6. The means for draining the clean water from the chamber 7 contains a heat exchange element 15 made in the form of a coil or finned tube located in containers 13 for the contaminated water concentrate, and a fine filter 16. The tank 10 includes a shut-off valve 17 for regulating the supply of clean water to the consumer.

The refrigerant circuit 4 contains cooling and heating elements 8 and 9, connected by heat exchange with the chambers, 6 and 7, respectively, a compressor 18, the output of which is connected in series with an air-cooled condenser 19 and a water-cooled condenser 20, and heat exchangers 21 and 22 The heat exchanger 21 at the inlet is connected to the inputs and outputs (not indicated) of the cooling and heating elements 8 and 9, and at the outlet it is connected to the inlet of the heat exchanger 22, connected by heat exchange with a tank for pure water 10, the output of which, in its in turn, it is connected to the compressor 18. In addition, at the inlet to the cooling and heating elements 9 there is a throttling capillary tube 23. The condenser with water cooling 20 is connected through heat exchange with the tank 13 for the contaminated water concentrate and the heat exchange element 15. The refrigerant circuit 4 is connected to cooling and heating elements 8 and 9 with the possibility of alternately freezing water and thawing ice in chambers 6 and 7 and transferring the heat of the refrigerant generated in the chamber during freezing of water into the chamber for thawing ice.

The control and monitoring means 5 comprises a controller 24 with a control panel (not shown) and associated temperature sensors 25 and 26 mounted, respectively, at the inputs and outputs of the cooling and heating elements 8 and 9 and inside the container 10, a water level sensor 27, mounted inside the mentioned tank 10, and solenoid valves mounted in the water circulation circuits 3 and refrigerant 4. In the water circulation circuit 3 are mounted: valve 28 - to regulate the supply of source water to the heat exchange chamber 6, valves 29 and 30 - for separation discharge of contaminated water concentrate and pre-treated water from chamber 6, valves 31 and 32 - for separating the discharge of contaminated water concentrate and clean water from chamber 7. In the refrigerant circuit 4 are installed: valves 33-37 for changing the direction of refrigerant flows in the cooling and heating elements 8 and 9 in alternate modes of freezing water and thawing ice, thermostatic valve 38 for regulating the temperature of the refrigerant (increase or decrease) in accordance with the algorithm of the system and valves 39 and 40 for monitoring the refrigerant pressure at the inlet and outlet of the compressor 18.

In the water circulation loop 3, the system also contains a cold heat exchange battery 41 mounted under the lower heat exchanger 2 and connected by heat exchange with the source water along its path after the coarse filter 12 into the chamber 6 of the upper heat exchanger 1 and with cold contaminated water concentrate and clean water in their course from the chamber 7 of the lower heat exchanger 2. The heat exchange cold battery 41 is made in the form of a closed thermally insulated container filled with a non-freezing heat-conducting substance, inside of which heat exchange elements 42 are arranged in the form of a coil for supplying source water to the chamber 6 and for alternately draining the contaminated water concentrate and clean water from the chamber 7. Moreover, the water-cooled condenser 20 is connected through heat exchange to clean water after it leaves the cold heat exchange battery 41 Using a cold heat exchange battery 41 to pre-cool the source water reduces system power consumption by up to 5%.

The system is controlled automatically by the control panel through the controller 24. In accordance with the specified algorithm, the controller 24 provides the following system functions:

- a change in the direction of water and refrigerant flows in alternate modes of freezing water and thawing ice;

- separation of streams of contaminated water concentrate and streams of previously purified and clean water at the outlet of the chambers of the upper and lower heat exchange devices;

- the transfer of heat of the refrigerant generated in the chamber during freezing of water in the chamber for thawing ice;

- water purification with separation of heavy water in the chamber of the upper heat exchanger, disposal of heavy water and purification of light water from impurities and dissolved salts in the chamber of the lower heat exchanger;

- cooling of clean water in the tank during its storage and use;

- production of edible transparent ice from purified water;

- increasing the concentration of liquid foods, wine and juices.

Technical parameters of the claimed system, including performance, energy consumption, overall dimensions and functionality, largely depend on the design of heat exchangers in which the processes of water recrystallization are carried out during its purification. The most efficient use of the system is provided by heat exchangers with an external cylindrical body (Fig. 2) and with an external body in the form of a truncated hollow cone oriented upward by the angle of the solution (Fig. 3).

Option 1. The use of a heat exchange device with a cylindrical body (Fig. 2, the cross section of the device).

The heat exchange device consists of an outer 43 and an inner 44 cylindrical-shaped body, a cylindrical-shaped partition 45, cooling and heating elements 8, a heating element 46, an air supply manifold 47, a cover 48, and a heat-insulating coating 49 fixed to the outer surface of the outer case 43.

The ratio of the height of the outer casing 43 to its diameter is 1.5-1.7, which ensures optimal functional parameters. The outer casing 43 contains an additional inner wall 50 of cylindrical shape, the height of which corresponds to the height of the outer casing 43. The cavity 51 between the outer casing 43 and the inner wall 50 is filled with a non-freezing heat-conducting substance, in which there are cooling and heating elements 8 made in the form of a refrigerant evaporator-condenser in the form of a coil with nozzles 52 for connection with a refrigerant circuit. On the inner surface of the outer casing 43 in front of the cooling and heating elements 8, a heat-reflecting coating (not shown) is fixed. Depending on the operating mode of the heat exchanger in the cooling and heating elements 8, either boiling refrigerant — freezing mode or condensing refrigerant — circulates through defrosting.

The inner case 44 is located coaxially with the outer case 43 and is made with closed ends. Placing the inner case 44 inside the outer case 43 allows the formation of a ring-shaped chamber 53 between their adjacent walls, which significantly reduces the duration of the freezing mode. At the same time, the inner case 44 is a displacer, reducing the amount of source water in the chamber 55, which also reduces the duration of the freezing mode. The height of the inner case 44 corresponds to the height of the outer case 43.

The partition 45 is fixed in the chamber 53 between the outer 43 and inner 44 cases with the formation, respectively, of the cooling 54 and recirculation 55 cavities communicating with each other through the water under the partition 45 and above it. The height of the partition 45 is 0.8-0.9 of the height of the outer casing 43, which allows free circulation of water in the freezing mode. The use of the partition 45 allows in the freezing mode to limit the front of water crystallization to a sufficiently narrow space of the cooling cavity 54, which further reduces the duration of the mode.

The heating element 46 is fixed in the upper part of the inner casing 44 and is made in the form of an electric heater or a tubular refrigerant condenser with a capillary tube to remove hot refrigerant vapor (not shown).

The air supply manifold 47 is mounted in the bottom of the outer case 43 in the cooling cavity 54. The cover 48 is capable of tightly locking the chamber 53. A pipe 56 for supplying water and an air valve 57 are made over the recirculation cavity 55 on the cover 48. A pipe 58 for draining the contaminated concentrate water and draining the purified water is made on the bottom of the outer casing 43 in said cavity 55.

The outer 43 and inner 44 cases, the partition wall 45 and the inner wall 50 are made of heat-conducting material. In this case, the partition 45 and the inner wall 50 are equipotential surfaces: the partition 45 is with a plus or minus sign, and the wall 50 is with a minus or plus sign, respectively, depending on the recrystallization mode.

Option 2. The use of a heat exchange device with a body in the form of a truncated cone, oriented upward by the angle of the solution (Fig. 3, cross section of the device).

The heat exchange device consists of an outer 59 and an inner 44 cases, a partition 45, cooling and heating elements 9, a heating element 46, a collector 47 for supplying air, a cover 60 and a heat-insulating coating 61 fixed to the outer surface of the outer case 59. The outer case 59 is made in the shape of a truncated hollow cone, oriented upward by the angle of the solution, and contains an additional inner wall 62 of a similar shape, the height of which corresponds to the height of the outer casing 59. The cavity 63 between the outer casing Ohm 59 and the inner wall 62 is filled with a non-freezing heat-conducting substance, in which there are cooling and heating elements 9, made in the form of a refrigerant evaporator-condenser in the form of a coil with nozzles 64 for connection with a refrigerant circuit. On the inner surface of the outer casing 59, in front of the cooling and heating elements 9, a heat-reflecting coating (not shown) is fixed.

The inner case 44 is made of cylindrical shape with closed ends and is located coaxially with the outer case 59. The height of the inner case 44 corresponds to the height of the outer case 59.

The partition 45 is made of a cylindrical shape and is fixed between the outer 59 and the inner 44 cases with the formation in the chamber 65, respectively, of cooling 66 and recirculation 67 cavities communicating with each other through the water under the partition 45 and above it. The partition 45 is located coaxially with the said buildings, and its height is 0.8-0.9 of the height of the outer casing 59, which allows free circulation of water in the freezing mode. The partition 45 provides a technical result similar to the previously discussed option with a cylindrical heat exchanger.

The construction and arrangement of the heating element 46, the collector 47, the nozzles 68 for supplying water and 69 for draining the contaminated water concentrate and clean water, as well as the cover 60 and the air valve 70 are similar to their implementation in a heat exchanger with an external cylindrical body.

The outer 59 and inner 44 cases, the partition wall 45 and the inner wall 62 are made of heat-conducting material. In this case, the partition 45 and the inner wall 62 are equipotential surfaces.

Heat exchangers with cylindrical and conical bodies are used in the system either together, for example, the upper device with a cylindrical body, and the lower one with a conical shape, or separately, two devices with external bodies of the same shape.

Presented in the description and in the figures of the drawings, the water purification system by the recrystallization method and the heat exchange devices used in it do not exhaust all possible options for their implementation, ensuring the achievement of the claimed technical result. In particular, any paired or unpaired number of heat exchangers of the claimed design can be used in the system, which makes it possible to create their unified series with different capacities. To reduce the duration of the ice thawing mode, the heat exchange devices may include additional heating elements located, for example, in the lower part of the heat exchange chamber or on the wall of the inner casing. Cooling and heating elements in heat exchangers can be made of a different shape or design, for example, in the form of multi-channel panels or electrical thermocouples.

The operation of the water purification system by recrystallization.

In the example described below, the system comprises (Fig. 1) an upper heat exchanger 1 with an external housing 43 of cylindrical shape (Fig. 2) and a lower heat exchanger 2 with an external housing 59 in the form of a truncated cone oriented upward with the angle of the solution (Fig. 3). Water purification is carried out in alternate modes of freezing water and thawing ice in chambers 53 and 65 of heat exchangers 1 and 2 and transferring heat of the refrigerant generated in the chamber during freezing of water into the chamber for thawing ice. Depending on the operating mode in the cooling and heating elements 8 and 9, either boiling refrigerant circulates - freezing mode, or condensing refrigerant - defrosting mode. The control and monitoring means 5 implements the program algorithm incorporated in the controller 24 for a corresponding change in the direction of water flows in chambers 53 and 65 and refrigerant in the cooling and heating elements 8 and 9, as well as short-term activation of the heating elements 46 and a compressor (not shown) for air supply in collectors 47 in the mode of freezing water.

The operation of the system is illustrated by the example of water purification with separation of "heavy" water in the chamber of the upper heat exchanger, disposal of "heavy" water and purification of "light" water from impurities and dissolved salts in the chamber of the lower heat exchanger.

1. Starting the system. The water supply to the chamber 53 of the upper heat exchanger 1.

On the control panel select the cleaning function with the separation of heavy water. After starting the system by pressing the "Start" button, the controller 24 controls the system in automatic mode. The valve 28 is opened and the source water through the filter 12 and the heat exchange cold battery 41 enters the chamber 53 of the upper heat exchanger device 1. After filling the chamber 53, the valve 28 closes.

2. The operation of the upper heat exchange device 1 in the freezing mode of "heavy" water.

Valves 34 and 35 open automatically, valves 33 and 36 are closed. When the upper heat exchanger 1 is operating in the freezing mode in the absence of water in the lower heat exchanger 2, the condensation of the refrigerant is carried out in condensers with air 19 and water 20 cooling. The refrigerant circulation in this mode is carried out in the direction of the dashed arrow in circuit 4 in FIG. 1. The refrigerant vapor compressed in the compressor 18 passes sequentially through the condenser sections with air 19 and water 20 cooling, valve 35, and then through the upper pipe 64 it enters the cooling and heating elements 9 of the lower heat exchanger 2. Through the lower pipe 64, the liquid refrigerant is removed from of the lower heat exchanger 2 and enters the capillary tube 23, from where it is directed to the heat exchanger 21 in a throttled state, after which it is heated to a temperature of 5 ° C and is supplied to the cooling through the lower pipe 52 the waiting and heating elements 8 of the upper heat exchanger 1. When passing the cooling and heating elements 8, the refrigerant boils off, cooling the source water in the chamber 53 and freezing “heavy” ice from it on the inner wall 50. The refrigerant vapor is discharged from the upper heat exchanger 1 through the upper pipe 52 and through the valve 34 and heat exchangers 21 and 22 is returned to the compressor input 18. After the specified duration of the freezing mode of the “heavy” ice on the inner wall 50, valve 29 opens by the command of the controller 24, through which non-frozen part of the source water is discharged into the chamber 65 of the lower heat exchange device 2, after which the valve 29 is closed.

3. The operation of the upper heat exchanger 1 in the mode of thawing "heavy" ice and the lower heat exchanger 2 in the mode of freezing "light" water.

At the command of controller 24, two groups of valves are simultaneously switched: valves 33 and 36 open, and valves 34 and 35 close. The lower heat exchanger 2 starts to work in the freeze mode of "light" water, and the upper heat exchanger 1 starts in the mode of thawing "heavy" ice. The synchronization of the operation of the heat exchange devices 1 and 2, the controller 24 provides according to a predetermined program algorithm with the participation of a thermostatic valve 38, which, based on the temperature sensors 25, shunts the capillary tube 23. The refrigerant is circulated in the direction of the solid arrow in circuit 4 in FIG. 1.

The refrigerant vapor compressed in the compressor 18 passes through air-cooled and water-cooled condensers 20 and through the valve 33 and the upper pipe 52 enters the cooling and heating elements 8 of the upper heat exchanger 1. As a result of heat exchange with “heavy” ice on the inner wall 50, the refrigerant condenses at a temperature of 20 ° C. Water formed during thawing of the “heavy” ice accumulates in the lower part of the chamber 53.

The liquid refrigerant through the lower pipe 52 exits the cooling and heating elements 8 and enters the heat exchanger 21, where it is cooled to 10 ° C, and then through the valve 37 passes through the capillary tube 23, where it is throttled and enters the lower pipe 64 of the cooling and heating elements 9 lower heat exchanger 2. In the chamber 65, the inner wall 62 is cooled to a temperature of from minus 3 ° C to minus 35 ° C, as a result of which the "light" water in the cooling cavity 66 is rapidly cooled with the formation of an annular front crystallization directed from the inner wall 62 to the partition 45. The temperature of the “light” water when it is cooled and the temperature of the refrigerant when it is heated as a result of heat exchange with water is controlled by temperature sensors 25. In accordance with the specified algorithm of the program, the controller 24 does not allow the possibility of a critical temperature drop in cooling cavity 66, which can lead to crystallization of the remainder of light water with a high content of organic and inorganic impurities, significantly reducing the quality of clean odes. When cooling "light" water, its density along the inner wall 62 decreases to 998.6-998.8 kg / m ³ , which causes a weak natural circulation of water between adjacent cavities 66 and 67, since the density of water in the cavity 67 does not change and is about 1000 kg / m ³ . After the formation of a thin layer of ice on the inner wall 62, an air compressor (not shown) is turned on by the controller 24 to supply compressed air to the cooling cavity 66 through the collectors 47. After that, at a given point in time, the heating element 46 is turned on for a short time. Supply to the cooling cavity 66 of air from the bottom and simultaneous short-term heating of “light” water in the upper part of the recirculation cavity 67 increases the intensity of its vertical circulation, which contributes to a faster water cooling and the growth of a clean and transparent layer of ice. At the same time, a decrease in the gradient of impurities at the ice-water interface is ensured and intercrystalline pollution of ice with salts and suspensions is reduced. The heat-insulating coating 61 and the heat-reflecting coating located on opposite surfaces of the outer wall of the outer casing 59 increase the efficiency of heat transfer from the cooling and heating elements 9 to the volume of water, which reduces the duration of the freezing mode in the chamber 65. In addition, the heat transfer efficiency is increased by filling the cavity 63 non-freezing heat-conducting substance.

As a result of heat exchange with “light” water during its freezing, the refrigerant in the cooling and heating elements 9 heats up and boils off at a temperature of minus 15 ° С. Through the upper pipe 64 and the valve 36, the refrigerant vapor is supplied to the heat exchangers 21 and 22, from where it enters the compressor 18.

After completion of the duration of the freezing mode of “light” water provided for in the program on the inner wall 62 in the lower heat exchanger 2, valves 30 and 32 open simultaneously at the command of controller 24. After this, the unfrozen balance of the “light” water containing the concentrate of impurities and salts from chamber 65 of the lower the heat exchange device 2 through the pipe 69, the heat exchange element 42 located in the heat transfer battery of the cold 41, and the valve 32 enters the tank 13. Also, the tank 13 through the pipe 58 and the valve 30 enters "t hard "water" from the chamber 53 of the upper heat exchanger 1. The excess water from the tank 13 is disposed of through the pipe 14. After draining the "heavy" and "light" water from the heat exchange chambers 65 and 53, the valves 30 and 32 are closed. The valve 28 opens and the source water is cooled in the heat exchange cold accumulator 41, through the pipe 56 it enters the heat exchange cavity 53 of the upper heat exchange device 1. After filling the heat exchange cavity 53, the valve 28 closes. The system is ready to change the recrystallization cycle.

4. The operation of the upper heat transfer device 1 in the freezing mode of "heavy" ice and the lower heat transfer device in the mode of thawing "light" ice.

At the command of controller 24, two groups of valves are simultaneously switched to the next recrystallization cycle: valves 34 and 35 open, valves 33 and 36 close. In the upper heat exchanger 1, freezing of “heavy” ice from the source water occurs on the inner wall 50, and in the lower heat exchanger 2, the “light” ice is thawed and clean drinking water is obtained. The refrigerant circulation in this mode is carried out in the direction of the dashed arrow in circuit 4 in FIG. 1.

The refrigerant vapor compressed in the compressor 18 passes through sections of condensers with air 19 and water 20 cooling, then through the valve 35 and the upper pipe 64 it enters the elements 9 of the lower heat exchange device 2, where it condenses at a temperature of 15-18 ° C, melting on the inner wall 62 frozen “light” ice. Through the lower pipe 64, the liquid refrigerant is discharged from the lower heat exchanger 2 into the capillary tube 23, throttled therein and enters the heat exchanger 21, where it is heated to a temperature of 5 ° C, after which it is supplied through the lower pipe 52 to the cooling and heating elements 8 of the upper heat exchanger 1. Passing through the mentioned elements 8, the refrigerant boils, cooling the source water and freezing “heavy” ice on the inner wall 50. Further, the refrigerant vapor exits through the upper pipe 52 and through the valve 34, the heat exchangers 21 and 22 are returned to the input of the compressor 18.

After the formation of the necessary layer of “heavy” ice on the inner wall 50 of the upper heat exchanger 1 and thawing of the “light” ice in the heat exchange chamber 65 of the lower heat exchanger 2, the valve 31 opens and clean drinking water through the heat exchange element 15 and the fine filter 16 enters the tank 10 for clean water. After draining clean water from the chamber 65, the valve 31 closes and opens the valve 29, through which the "light" water enters the chamber 65 from the chamber 53 of the upper heat exchanger 1. The valve 29 closes. The system is ready for the next change of recrystallization modes in heat exchangers 1 and 2, in which the “heavy” ice will thaw in the upper heat exchange device 1 and the “light” water will freeze in the lower heat exchange device 2. The specified mode is considered above (cycle 3).

During the operation of the system, pure drinking water is accumulated in the tank 10 and cooled by means of a heat exchanger 22. The level and temperature of the clean water in the tank 10 are controlled by level sensors 27 and temperature 26. The clean drinking water from the tank 10 is discharged to the consumer through the valve 17.

The operation of the system using the effect of electrolysis in the mode of freezing water.

To purify water with a high degree of pollution, the electrolysis effect is additionally used, which is formed in the cooling cavities 54 and 66 between the equipotential surfaces of the partition 45 and the inner wall, respectively, 50 and 62 when they are connected to an external direct current source. In this case, the partition 45 is connected to the positive contact, and the said inner walls to the negative contact or vice versa, taking into account the change of recrystallization modes.

Depending on the degree of contamination of the source water and climatic conditions, the duration of the mode of freezing water in heat exchangers 1 and 2 is from 0.2 to 1.5 hours, and the mode of ice thawing is 0.5 hours.

The inventive design of the system and heat exchangers was tested during the treatment of contaminated and marine (with salt content up to 4.5%) water. The test results confirmed the claimed technical result. In particular, the use of a heat-exchange battery in the system reduces the duration of water cooling and ice freezing in the upper heat-exchange device by 24-32%. The use of a water-cooled condenser reduces the condensation temperature of the refrigerant from about 40 ° C to about 30 ° C, which increases the cooling capacity of the compressor and reduces the duration of the freezing mode in the upper and lower heat exchangers. Using the effect of electrolysis during freezing of water allows reducing the content of undesirable impurities in it from 40% to 90%. The use of an additional heating element reduces the duration of ice thawing.

The combination of a sufficiently large productivity and high quality water purification in the system allows it to be used for the treatment of source water with a wide range of pollution by organic and inorganic substances.

Claims (10)

1. The water purification system by recrystallization, consisting of at least two heat exchangers, containing chambers for freezing water and thawing ice and cooling and heating elements, a water circulation circuit connected to the chambers of the heat exchangers with the possibility of draining the previously purified water from one chamber and supplying it for final cleaning to another chamber, a refrigerant circuit, connected to cooling and heating elements with the possibility of alternating freezing water and thawing ice in the chambers of heat exchangers and transferring heat of the refrigerant generated in the chamber during freezing of water to the chamber for thawing ice, and control and monitoring means connected to the above-mentioned circuits with the possibility of changing the direction of water and refrigerant flows in alternating modes of freezing water and thawing of ice, while the water circuit contains a means for supplying source water, a means for draining a concentrate of contaminated water, a means for draining pre-treated water, medium in for draining clean water, a container for clean water and a container for contaminated water concentrate, and the refrigerant circuit contains a compressor, a water-cooled condenser associated with heat exchange with a container for contaminated water concentrate after it is drained from the chambers of heat exchangers, and two heat exchangers, characterized in that the heat exchange devices are cascaded one above the other and contain one chamber made with the possibility of dividing it into cooling and recirculating water interconnected by water cavity, water circulation between the said cavities and the formation of equipotential surfaces in the cooling cavity during freezing of water, the refrigerant circuit contains an additional air-cooled condenser connected at the inlet and outlet, respectively, with the compressor outlet and the water-cooled condenser inlet, the first heat exchanger at the input it is connected to the inputs and outputs of the cooling and heating elements, and at the output it is connected to the input of a second heat exchanger, the output of which is connected to about heat exchange with a container for clean water and connected to the compressor inlet, the chamber of the upper heat exchanger at the inlet is connected to the means for supplying the source water and at the outlet is connected to the means for draining the contaminated water concentrate and the means for draining the previously purified water, and the chamber of the lower heat exchanger at the inlet it is connected with means for draining the pre-treated water from the chamber of the upper heat exchanger device and at the outlet it is connected with means for draining the concentrate of contaminated water and redstvom drain clean water. 2. The system according to claim 1, characterized in that the control and monitoring means is made with the additional possibility of separating the source water in the chamber of the upper heat exchanger into heavy and light water, while the heavy water is removed by means for draining the contaminated water concentrate, and light water served in the chamber of the lower heat exchange device by means for draining pre-purified water. 3. The system according to claim 1, characterized in that the control and monitoring means comprises a controller and associated control valves mounted in the water and refrigerant circuits, temperature sensors mounted at the inlets and outlets of the cooling and heating elements and inside the tank for clean water, and a water level sensor mounted inside the tank for clean water, while the control valves are made in the form of electromagnetic valves for water and refrigerant. 4. The system according to p. 1, characterized in that the system is made with a heat exchange battery connected by heat exchange with the source water along the chamber of the upper heat exchanger and with a concentrate of contaminated water and clean water along their course from the chamber of the lower heat exchanger, and the condenser with water cooling is additionally connected through heat exchange with clean water along the way from the heat exchange battery. 5. The system according to claim 1, characterized in that the means for supplying the source water comprises, in the direction of the chamber of the upper heat exchanger, a heat exchange element located in the heat accumulator, and a coarse filter, means for draining the concentrate of contaminated water along the way from the chamber a heat exchange device, a container for contaminated water concentrate connected by heat exchange with a water-cooled condenser, and a pipe for draining into the sewer, means for draining the contaminated water concentrate, and means for clean water flow are made with a common exit from the chamber of the lower heat exchanger and contain along the path from the said chamber a common heat exchange element in the heat exchange battery, and further along the course of the contaminated water concentrate contain the said container for the contaminated water concentrate and a pipe for draining into the sewer, and along the way clean water contains a second heat-exchange element located in a water-cooled condenser, a fine filter and a bactericidal lamp, and the tank for clean water contains a shut-off valve to regulate the supply of water to the consumer. 6. The heat exchange device in the system according to claim 1, consisting of an outer case and an inner case located in the outer case along its longitudinal axis with the formation of a chamber between their walls, and cooling and heating elements mounted on the outer case, while the inner case is made with closed ends, and the outer casing contains at least one drain pipe and is made with thermal insulation of the outer surface and with the possibility of locking the lid, characterized in that it further comprises a partition of qil a drone shape fixed in the said chamber with the formation of cooling and recirculation cavities, respectively, communicating with each other through water under the partition and above it, a heating element and means for supplying air, while the inner case is cylindrical in shape, the partition is coaxial with the outer and inner cases , the means for supplying air is mounted on the bottom of the outer case in the cooling cavity, and the heating element is fixed in the upper part of the inner case. 7. The heat exchange device according to claim 6, characterized in that the outer casing is cylindrical. 8. The heat exchange device according to claim 6, characterized in that the outer casing is made in the form of a truncated cone, oriented upward by the angle of the solution. 9. The heat exchange device according to claim 6, characterized in that the outer casing is made with an additional inner wall, the shape and height of which correspond to the outer casing, cooling and heating elements are located between the walls, and the height of the partition is 0.8-0.9 from the height of the outer casing. 10. The heat exchange device according to claim 6, characterized in that the partition and the inner wall of the housing are configured to be connected to a current source.

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