RU2625247C1 - Method for reverse osmosis treatment of sanitary and hygienic water in closed circuit in gravity-free environment - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: method of reverse osmosis treatment of sanitary and hygienic water from a detergent and impurities in gravity-free environment is based on the use of membrane technology, in which the source water is supplied to the receiving source water tank, from where it is pumped to the reverse osmosis filter element, wherein it is possible to return the concentrate to the circulation circuit, contaminated water circulating in a circuit with constant volume tank is simultaneously filtered through the reverse osmosis membrane, and circulation circuit of purified water source is made up with gradual increase of concentration up to the maximum allowable degree of purification and providing clean water recovery ratio, determined by the ratio of these concentrations.

EFFECT: increased degree of water extraction during continuous process of regeneration in gravity-free environment, ensuring a long service life.

3 cl, 2 dwg

Description

The invention relates to the field of life support systems for crews of spacecraft (spacecraft, orbital stations), as well as individual households, namely, regenerative water supply systems.

A known method of regeneration of sanitary water based on filtration followed by sorption treatment with ion-exchange resins and activated carbon (Samsonov NS, Farafonov NS, Abramov L.Kh. Hygiene water recovery aboard the space station / NS Samsonov // 4 ^th European Symposium on Space environmental control systems ESA SP-324 vol 2, 21-24 oct. 1991 - P. 649-651 .; Bobe L.S., Sinyak Yu.E., Berlin AA, Soloukhin V.A. et al. Ecological and technical system [Text] / L.S. Bobe // M.: Publisher MAI, 1992, 72 p.).

The disadvantages of the above method include the unsatisfactory quality of purified water when using detergents of general use that do not dissociate into ions. The necessary degree of water purification can be achieved only with the use of detergents dissociating to ions. Since activated carbons and ion-exchange resins are used for cleaning, the installation life is limited by the relatively small capacity of the sorption filter. A known method of regeneration of sanitary water, in which contaminated water is purified by baromembrane methods, namely ultrafiltration, followed by purification by reverse osmosis. At the ultrafiltration stage, clarification of sanitary water is performed; at the stage of reverse osmosis purification, water is purged from salts and other low molecular weight pollutants (Starikov S.E. Regeneration of sanitary-hygienic water based on baromembrane methods for long-term space expeditions / dissertation for the study of academic degree. . - Moscow, 2009, p. 68). The disadvantages of the above method include the frequency of the water regeneration process with the need to backwash the filter based on the ultrafiltration membrane with a permeate reverse osmosis filter, as well as the relatively low degree of water extraction (80%). It is not indicated how the reception (collection) of contaminated water in microgravity is carried out.

The solution AU 2007202471 is known in which a device for disinfecting a reverse osmosis system is described, including a pump transporting a disinfectant from a special tank to pipelines of a reverse osmosis cleaning system, the disinfectant supply line being connected to a reverse osmosis system pipeline equipped with a shut-off device that shuts off the water flow when disinfectant is supplied and opens during the operation of the reverse osmosis system.

This device purifies running water and there is no equipment that provides multiple purification of the same water with a high recovery ratio.

The closest analogue is patent RU2536993 for a device for producing ultrapure water according to the reverse osmosis principle, in the primary and / or secondary circuit of which there is a device for recording organic and (or) inorganic deposits, connected to a data processing device, and an elastic circuit is integrated in the secondary circuit capable of expanding a buffer vessel adapted to perform backwashing of the membrane with a permeate, the device for recording organic and / or inorganic deposits ability to run at the appropriate backwash pollution degree. The essence of the prototype and the previous analogue is that the source water enters the receiving tank of the source water, from where it is pumped into the reverse osmosis filter element. The flow of water passes along the surface of the membrane under pressure and is divided into a stream of purified water, which is then distributed to consumers, and a stream of concentrate that leaves the reverse osmosis element and is diverted to the sewer or drainage. It is possible to return water to the receiving tank in case of lack of water in it.

This device purifies running water and there is no equipment that provides multiple purification of the same water with a high recovery ratio.

The objective of the invention is to develop a method and system for the regeneration of sanitary water, which allows for the reception of contaminated water under zero gravity conditions, its purification to the required quality, storage and delivery of clean water, as well as a long cleaning resource.

Effect: provides an increase in the degree of water extraction during the continuous regeneration process in zero gravity, ensuring a long service life.

The specified technical result is achieved due to the fact that the claimed method of reverse osmosis cleaning of sanitary water from detergent and contaminants in zero gravity conditions, based on the use of membrane technology, in which the source water is supplied to the source water receiving tank, from where it is pumped to the reverse osmosis filter element moreover, they realize the possibility of returning the concentrate to the circulation circuit, characterized in that they are simultaneously filtered through reverse osmosis m a membrane of contaminated water circulating in a circuit with a constant-volume tank fed with the circulation circuit of the source purified water with a gradual increase in concentration to the maximum permissible degree of purification and providing a clean water recovery coefficient determined by the ratio of these concentrations.

It is preferable to introduce a constant volume tank into the circulating water treatment loop, which is connected to a variable volume receiving tank incorporating a bag of polymer material, so that as water is taken through the reverse osmosis membrane, the constant volume tank of the circulation loop is fed with raw water, and in front of the receiving tank, a gas-liquid mixture separation unit with a centrifugal separator is installed, while on the discharge line of the high pressure pump a vortex separator is installed, in addition, a silver ionizer is installed in front of the tank of purified water of variable volume, which ensures preservation of the purified water before it enters the tank, and in addition, a purified water pump is used, after which an ultraviolet disinfectant is installed, which ensures the final disinfection of water before it is dispensed to the consumer.

Preferably, the ratio of the amount of purified water before the change (emptying) of the concentration capacity to the volume of the circulation circuit is selected equal to 1/50 (the degree of concentration of contaminants is 50). This allows you to ensure the life of the system with a coefficient of water extraction of at least 98% with a minimum membrane selectivity for detergent equal to 99.6%.

To implement the method, it is preferable to use a device for reverse osmosis treatment of sanitary water generated during sanitary-hygienic procedures and washing, which includes a receiving tank of variable volume, a coarse pre-filter, reverse osmosis module, a receiving tank of purified water, pumps connected at flexible piping, equipped with shut-off and control valves, moreover, the device is arranged to circulate contaminated water, excellent characterized in that it further comprises a constant-volume concentration tank having a feed channel for the source to be purified water, the function of which is to concentrate the contaminants in proportion to the volume of purified water, while the constant-volume tank is connected to a receiving tank of variable volume having a package of polymer material in its composition, such so that as water is taken through the reverse osmosis membrane, the source water is sucked into a container of constant volume, and in front of the receiving tank a gas-liquid mixture separation unit with a centrifugal separator was installed, while a vortex separator was placed on the discharge line of the high pressure pump, and a silver ionizer was installed in front of the treated water tank of variable volume, and an ultraviolet disinfectant was installed at the outlet of the pump located in front of the purified water delivery channel.

Preferably, to ensure a resource of purified water with a water recovery factor of at least 98%, the device has a circulation volume of 24 l, a water flow rate of 6 l / min in the circulation circuit and is capable of flushing the circulation circuit with the displacement of contaminated water.

Preferably, after the coarse filter, a fine filter is additionally installed.

Preferably, a gas-liquid mixture separation unit with a centrifugal separator is installed in front of the receiving container.

Preferably, a vortex separator is installed on the discharge line of the high pressure pump.

Preferably, the device comprises a two-stage disinfection system for purified water using a silver ionizer and an ultraviolet disinfectant.

Preferably, a bypass line with solenoid valves is integrated in the reverse osmosis treatment unit. This allows the return of contaminated due to diffusion of contaminants through the permeate membrane into the circulation circuit. The fundamental difference of the invention is the introduction of a constant volume tank into the circulating circuit for treating recycled water. This capacity in the prototypes is missing. The introduction of this tank allows the concentration of pollutants in a closed circulating circulation loop up to 50 times with a high recovery rate of pure water (up to 98%). The second difference of the invention is the connection of the receiving tank of variable volume, which includes a bag of polymer material, with a capacity of constant volume so that as water is taken through the reverse osmosis membrane, the source water is sucked into the tank of constant volume, which ensures a constant volume of the circulation circuit cleaning up.

The third difference of the invention is that a gas-liquid mixture separation unit with a centrifugal separator is installed in front of the receiving tank, and a vortex separator is installed on the discharge line of the high pressure pump. These blocks ensure the functioning of the proposed system in zero gravity. The prototypes presented in their composition do not have and cannot function in zero gravity.

A fourth feature of the present invention is the introduction of a reverse osmosis system for treating a container of purified water of variable volume, incorporating a bag of polymer material in front of which a silver ionizer is installed, which preserves the purified water before it enters the tank. The reverse osmosis treatment system also includes a pump for the release of purified water, after which an ultraviolet disinfectant is installed, which provides a final disinfection of water before it is dispensed to the consumer. In the presented prototypes, the possibilities of preserving, storing, dispensing and finishing disinfecting purified water are not provided.

A brief description of the drawings.

In FIG. 1 shows an example of a block diagram of a device for reverse osmosis treatment of sanitary water that implements the method, where 1 is a compartment for water procedures or washing; 2 - gas-liquid mixture separation unit with centrifugal separation; 3 - receiving capacity of variable volume; 4 - concentration capacity of constant volume; 5 - coarse pre-filter; 6.1, 6.2, 6.3 - pumps; 7 - ultraviolet disinfectant, 8 - vortex separator, 9 - reverse osmosis filter; 10 - pressure gauge; 11 - control valve; 12.1, 12.2, 12.3, 12.4 - shut-off valves (valves); 13 - silver ionizer; 14 - capacity of purified water; 15 - fine pre-filter.

In FIG. 2 shows a schematic flow chart of the implementation of the reverse osmosis method for sanitation water, where 16 - ORP - water treatment compartment, 17 - ultrasonic treatment - contaminated water unit, 18 - UMA - membrane treatment unit, 19 - UOV - water disinfection unit.

The implementation of the invention

The claimed technical result is achieved by preliminary mechanical cleaning and water treatment followed by reverse osmosis by tangential filtration with the circulation of contaminated water in a closed circuit and the concentration of pollutants in a replaceable (emptied) circulation tank of constant volume fed with the source of purified water, as well as by introducing separators into the water treatment system when receiving contaminated water and in the circulation circuit to ensure Process filtration and reverse osmosis under conditions of weightlessness.

The reverse osmosis system for sanitary water works in two modes:

1) in the mode of issuing purified sanitary water and receiving contaminated water;

2) in the mode of purification (regeneration) of contaminated water.

The system can operate in a combined mode, when water is simultaneously received and dispensed and contaminated water is cleaned. The mode of issuance of purified sanitary water and the intake of contaminated water. Since there is no gravitational deposition mechanism under zero gravity conditions, it is necessary to use special methods for transporting contaminated water from the water treatment compartment. This problem is solved by introducing into the composition of the reverse osmosis system of sanitary-hygienic water a gas-liquid mixture separation unit (GHS) pos. 2 (Fig. 1), which includes a fan for transporting liquid with an air stream into this unit and a centrifugal pump-separator for separating gas-liquid phases and transporting liquid to a storage tank.

When the unit is put into standby mode, water intake mode is automatically activated. When this starts the separation unit GZhS pos. 2 (Fig. 1) (power is supplied to the fan and the separator of the GHS unit). The unit is ready to receive contaminated water.

Upon request, from the compartment of water procedures 1, clean water is supplied via pump 6.3 from tank 14, an ultraviolet water disinfectant 7 passes and is given for consumption. After use, the water is carried away by the air flow in the separation unit of the GWS pos. 2, is separated from the air and transported to a container of contaminated water of variable volume 3.

Tanks of variable volume 3 and 14 are a metal body, in which there is a polymer tank capable of compression and expansion (the cavity between the polymer tank and the body communicates with the atmosphere) and providing water reception and delivery in zero gravity conditions.

The mode of purification (regeneration) of contaminated water

The mode of purification (regeneration) of contaminated water starts and stops on command from the control panel or automatically. The start of the regeneration mode in automatic mode occurs when filling the tank of variable volume 3 (Fig. 1) or when emptying the tank of purified water 14. Automatic stopping the regeneration mode when emptying the tank of variable volume 3 or when filling the tank of purified water 14.

In regeneration mode, pumps 6.1 and 6.2 are started. Contaminated water begins to circulate through the circulation circuit, tangentially passing through the reverse osmosis element. Circulation is carried out through a constant volume tank 4, in which the concentration of contaminants occurs. The concentration tank of constant volume 4 is a metal body in which there is a polymer tank capable of compression and expansion, and air is pumped out from the cavity between the polymer tank and the body. The polymer container is pressed against the walls of the housing and has a constant volume. It is possible to empty this tank without dismantling by applying pressure to the cavity between the polymer tank and the housing, as well as the possibility of its subsequent filling. When emptying the tank 4, use the valve 12.1, through which it is emptied. As water passes through the membrane of the reverse osmosis filter 9, the circulation capacity of the constant volume is fed with the source of purified water. Thus, the problem of maintaining a constant volume of the circulation circuit is solved.

In this case, after the coarse filter 5, an additional fine filter 15 can be additionally installed, during the cleaning of which the valve 12.2 is closed. The necessary pressure in the reverse osmosis filter 9 is set using the valve 11 and the pressure gauge 10. When the flow of contaminated water through the reverse osmosis filter 9 is circulated, the initial flow is divided into a concentrate stream and a purified water stream (filtrate, permeate). The purified water enters the silver ionizer 13, where it is canned and transported to a container of purified water of variable volume 14. The canned water can be stored for a long time without losing its quality.

When carrying out reverse osmosis cleaning under zero gravity, air cannot enter the reverse osmosis filter 9. The task of separating air at the inlet of the reverse osmosis filter is solved by introducing a vortex separator 8 into the high-pressure pump discharge line.

When cleaning is carried out in a concentration tank of constant volume 4, the concentration of pollutants is gradually increased to a concentration that is maximum permissible for the degree of purification and provides a given life of the system, after which the tank 3 is replaced with a new one or its emptying followed by refueling with clean water.

It is intended to flush the circulation circuit of the system by displacing the contaminated water concentrate with clean water.

To ensure the reliability and safety of the reverse osmosis water treatment system for humans when it is used in a pressurized object, the system includes a two-stage disinfection system for purified water using a silver ionizer and an ultraviolet disinfectant.

During prolonged shutdowns between regenerations, the contaminants in the circulation circuit pass through the reverse osmosis membrane through diffusion and end up in the channel of purified water. To solve the problem of water of inadequate quality entering the purified water tank 14, a bypass is provided in the claimed water purification system for flushing the purified water channel before starting regeneration. To carry out flushing, shut-off valves (valves) 12.3, 12.4 are provided in the installation. In standby mode, valves 12.3, 12.4 are closed. When the regeneration mode is activated, one valve 12.3 opens and the flushing of the purified water channel with fresh filtrate begins and returns to the circulation circuit. After 15 minutes of flushing, valve 12.3 closes automatically and valve 12.4 opens. Water regeneration begins. When the volume of containers 3, 4 and 14 is 20 liters, the volume of pipelines and filters of the circuit is 4 liters, the flow rate of contaminated water in the circulation circuit is 6 l / min and the concentration of pollutants from C _start = 5 g / l to C _con = 250 g / l a reverse osmosis system for cleaning sanitary water with a pressure drop across the federal district equal to 1 MPa ensures the purification of at least 1200 liters of contaminated water without replacing (emptying) the concentration capacity of a constant volume of pos. 4. At the same time, the system carries out at least 50 cleaning cycles. The water recovery factor is at least 98%.

The coefficient of water extraction is calculated by the formula:

where: G _O.V. - amount of purified water;

G _Z.V. - the amount of contaminated water received;

From the _beginning - the initial concentration of pollutants;

C _con - final concentration of pollutants.

.

.

Work resource before change (emptying) of tank 4:

,

,

where: V is the concentration volume:

V = V ₄ + V _k = 20 + 4 = 24 l

V ₄ - the volume of the concentration tank of constant volume 4 (Fig. 1);

V _to - the volume of the circulation circuit.

The degree of concentration of pollution:

.

.

Minimum membrane selectivity:

,

,

where C _f is the concentration of detergent in the filtrate (C _f = 1 g / l at the maximum allowable COD (b) of the filtrate equal to 150 mg O ₂ / l, in accordance with GOST R 50804-95).

Purification of contaminated sanitary water is as follows (see diagram of Fig. 2). Water from the compartment of water procedures OVP 16 (shower, washing room, washing machine) enters the site of contaminated water UZV 17, where it accumulates. After the accumulation of the required amount of contaminated water, the treatment (regeneration) mode automatically starts. Water is supplied to the membrane treatment unit UMO 18, where the initial stream is divided into a stream of purified water and a stream of concentrate, which returns to the site of contaminated water. The purified water enters the purified water unit (WWW) 19, where it accumulates and is discharged into the water treatment compartment.

Claims (3)

1. A method for reverse osmosis cleaning of sanitary-hygienic water from detergent and contaminants in zero gravity conditions, based on the use of membrane technology, in which the source water is supplied to the source water receiving tank, from where it is pumped into the reverse osmosis filter element, and the concentrate can be returned to the circulation circuit, characterized in that at the same time they filter through the reverse osmosis membrane of contaminated water circulating in the circuit with a standing tank volume of water, and replenishment of the circulation circuit with the source of purified water with a gradual increase in concentration to the maximum permissible degree of purification and ensuring the coefficient of extraction of pure water, determined by the ratio of these concentrations. 2. The method according to p. 1, characterized in that a constant-volume tank is introduced into the circulating circuit for circulating water purification, which is connected to a receiving tank of variable volume, which includes a package of polymer material, so that as water is taken through reverse osmosis the membrane is fed with a constant volume tank of the circulation circuit with source water, and a gas-liquid mixture separation unit with a centrifugal separator is installed in front of the receiving tank, while the pump is on the discharge line a high-pressure vortex separator is installed, in addition, a silver ionizer is installed in front of the tank of purified water of variable volume, which ensures the preservation of purified water before it enters the tank, and in addition, a purified water pump is used, after which an ultraviolet disinfectant is installed, which provides final disinfection of water before issuing it to the consumer. 3. The method according to p. 1 or 2, characterized in that the ratio of the amount of purified water before changing (emptying) the concentration capacity to the volume of the circulation circuit is selected equal to 1/50 (the degree of concentration of pollution is 50).

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