RU90351U1 - MEMBRANE FILTER FOR CLEANING WATER - Google Patents

Abstract

1. Membrane filter for water purification, containing a membrane for reverse osmosis, located in a separate housing equipped with an inlet and two outlet, one of which is designed to remove drainage water, and the other to dispense purified water, as well as a pre-treatment device containing a filter purification from mechanical impurities and an activated carbon filter, characterized in that the membrane filter is equipped with an additional water treatment unit installed at the entrance to the membrane housing and containing installed, an ion-exchange microglobular filter containing silver, a liquid polyhexamethylene guanidine dispenser made in the form of a capsule with microscopic holes and a polyphosphate dispenser made in the form of a container with porous walls containing polyphosphate in the solid state, both dispensers installed in the stream of purified water . ! 2. The membrane filter for water purification according to claim 1, characterized in that the diameter of the holes of the capsules of the dispenser of the liquid polyhexamethylene guanidine is 0.01-0.25 mm, an air outlet is made in the upper part. ! 3. The membrane filter for water purification according to claim 1, characterized in that the pore diameter of the capacity of the polyphosphate dispenser is 0.15-1.2 mm.

Description

The invention relates to liquid separation devices using semi-permeable membranes by the reverse osmosis method, as well as to devices protecting the membranes from contamination.

The filter, operating on the principle of reverse osmosis, contains the main element, which allows to obtain water with a high degree of purification - this is a thin-film membrane. It is a kind of grid, the cell size of which is comparable to the size of a water molecule. Either water molecules themselves or substances whose molecules are even smaller — oxygen, hydrogen, and other dissolved in water — can pass through such a “grid”. As a result, almost all dissolved components, as well as salts of heavy metals, organic impurities and bacteria, are removed from the water. All other structural elements of the reverse osmosis system provide favorable conditions for the operation of such a membrane. However, the small pores of the membrane would have to quickly become clogged with dirt if ordinary tap water would flow into it. In order to prevent this from happening, prefilters are installed in front of the membrane - several stages of preliminary cleaning. Among them, there is always a stage of cleaning from mechanical impurities, which delays suspensions, sand and insoluble impurities with a particle size of more than 5 microns. Another stage provides chemical cleaning of chlorine, chlorine compounds, pesticides, organics, etc. using sorption on activated carbon. Depending on the quality of the source water, the number of steps in the prefilter can be increased. During operation, filtered salts and various impurities gradually accumulate in front of the membrane, due to which it can become clogged and stop working. For the continuous discharge of these "wastes" along the membrane, a forced flow of water is created, washing away concentrated contaminants into the drainage. This increases the productivity and service life of the membrane. To achieve normal membrane performance, water should be supplied to it under a pressure of 3.5-4 atmospheres. Such pressure is commonplace for most municipal water pipelines in large cities. At pressure; water less than 2-2.5 atmospheres (including when taking water from a tank without pressure) requires a pressure increase pump. If treated water is consumed unevenly and its flow rate may increase periodically, the treatment system is usually supplemented with a tank for storing clean water. Sometimes a more expensive method is used - the systems are equipped with a significantly more powerful pump and a more efficient membrane.

The filtering ability of a reverse osmosis system is truly unique. None of the filters that work according to another principle - mechanical cleaning, adsorption or ion exchange - can provide this degree of purification. It is very important to understand that even the best of “simple” household filters do not remove or far from completely remove pesticides, bacteria, trihalomethanes and other carcinogenic, organochlorine compounds, as well as heavy metals and radionuclides from the water, but the possibility of clogging the membrane makes us look for ways cleaning up.

Known membrane filter [1], containing two membranes, forming a device for two-stage water purification. At the first stage, a low-pressure membrane system is used to pre-treat water using its “softening” and binding of pollution particles in water with pH control. Direct and reverse water flows are also used to reduce particle deposition on the membrane. In the second stage, which takes place under high pressure, water is further “softened” by the removal of dissolved compounds, such as calcium, magnesium, carbonate, sulfate, silicon, etc.

The disadvantage of the filter is its high cost and complexity. The installation requires two pumps - low and high pressure.

Known reverse osmosis membrane filter [2], containing the main filter layer and a separation layer formed on the surface of the main and containing an electrically neutral polymer, the task of which is to separate an electrically neutral organic substance. The filter has a very good filtering ability and bacteriostatic properties, but does not solve the problem of cleaning the membrane from carbonate deposits.

A known apparatus for the production of ultra pure water [3], which includes a column with a cation exchange resin, a decarbonization column, an anion exchange resin column and a pH regulator to change the electrokinetic potential of the impurities contained in the water. The device can control the quality of water at the inlet and outlet of the reverse osmosis device.

A known method of water purification and membrane installation for its implementation [4]. The invention relates to the field of membrane separation of solutions and suspensions and can be used in methods and means of purification of natural waters, industrial effluents, in drinking water supply systems, utilities and various industries. The method of water purification from mechanical impurities, microorganisms, macromolecular compounds and salts of heavy metals by ultrafiltration includes preliminary rough water purification, the stage of filtering water through electrified membranes by moving it over each membrane at a speed of 1-2 m / s with a pressure of 0.3 ± 0.1 MPa above the membrane and atmospheric pressure below it. The filtered water is aerated before filtration, and the stages of filtration and regeneration are interchanged.

The membrane installation includes a pump for supplying purified water, a coarse filter, a collection tank for repyat, a concentration tank, a buffer tank, a pump for supplying water from a buffer tank to a concentration tank, a pump for supplying repiate to a consumer, and a control unit located on the frame and connected by pipelines regulatory equipment. The membrane installation according to the second embodiment includes a pump for supplying purified water, a coarse filter, a collection tank for repiate, a container for concentration, a pump for supplying repiate to the consumer and control and control equipment located on the frame and interconnected by pipelines. The method and devices solve the problem of obtaining repiate of high purity while increasing the productivity of the process. The technical result is an increase in the efficiency and productivity of water treatment.

The disadvantage of the device is its complexity and, accordingly, cost, which is unacceptable for a household appliance. However, in its technical essence, this device is closest to the claimed device and can serve as a prototype.

The objective of the proposed device is to obtain high-quality drinking water in a domestic environment, while maintaining the performance of the membrane by preventing the formation of carbonate deposits and bacterial colonies on its surface, as well as the implementation of bactericidal water purification.

The problem is solved as follows. A membrane filter for water purification, containing a membrane for reverse osmosis, located in a separate housing equipped with an inlet and two outlet, one of which is designed to remove drainage water, and the other to dispense purified water, as well as a pre-treatment device containing a filter for cleaning mechanical impurities and an activated carbon filter for trapping chlorine.

Its distinctive feature is that the membrane filter is equipped with an additional water treatment unit installed at the entrance to the membrane housing and contains sequentially installed ion-exchange microglobular filter containing silver, a liquid polyhexamethylene guanidine dispenser made in the form of a capsule with microscopic holes with a hole diameter of 0, 01-0.25 mm, in the upper part there is a hole for air outlet, and a polyphosphate dispenser, the latter made in the form of a container with solid walls, the pore diameter of which is 0.15-1.2 mm, and contains polyphosphate in the solid state, both dispensers installed in the stream of purified water.

Figure 1 and 2 shows a General view of the device.

The filter contains a membrane 1 located in the housing 2, with an inlet pipe 3 and an outlet drain pipe 4 and a pipe 5 for purified water. At the entrance to the housing 2, a prefilter is installed - a pre-filter in the form of an additional unit placed in a separate housing 6 and containing a coarse filter element 7, an ion-exchange microglobular filter 8, containing silver as a part of the microglobule, then activated carbon filter 9, polyhexamethylene guanidine dispenser 10 and a polyphosphate dispenser 11, the latter being made in the form of containers with porous walls and installed in a stream of purified water. The housing 6 has an inlet 12 for the intake of contaminated water and an outlet 13 connected to the inlet pipe 3 of the housing 2.

The device operates as follows. The purified water is first supplied to the prefilter, where it first passes through the coarse filtering element 7, where the water is cleaned of mechanical impurities, then the water enters the ion exchange filter 8, in which the metal oxides - iron, copper, aluminum, etc. are deposited. Silver, which is part of the microglobul of the ion-exchange resin of filter 8, has a bactericidal effect on water, which is further enhanced by the introduction of polyhexamethylene guanidine into the water. The latter is located in the dispenser 10, which is a capsule with microscopic holes. The dispenser 10 is placed in a stream of purified water. Liquid polyhexamethylene guanidine, under the influence of a high-speed flow through the aforementioned holes, flows out of the capsule with microscopic doses, dissolves in water and kills the microflora. The size of the holes in the capsule is selected in accordance with the required flow rate. In the absence of water consumption, i.e. lack of flow, polyhexamethylene guanidine is not consumed.

Next, the flow of water is directed to the polyphosphate dispenser 11, which is a container made of a porous material. Polyphosphate is in this container in a solid state. Under the influence of water penetrating into the tank, polyphosphate dissolves and accumulates in the tank in the absence of water flow. With the appearance of a water flow (water draw-off) by a high-pressure head, polyphosphate molecules are removed from the tank and act as an antiscaleant (precipitation inhibitor) and react with carbonates, which have low solubility and together with sulfates, phosphates, fluorides, borates, silicates, hydroxides of iron, manganese and aluminum form large-scale mineral deposits on the membrane surface, which do not penetrate through the membrane openings and are easily removed by the flow of water into the drainage.

The applicant made an experimental device of this membrane filter, which showed satisfactory results.

List of used literature.

1. US patent No. 6,113,797, 2000, high-purity membrane filter,

2. US Patent No. 6,413,425, 2002. Membrane reverse osmosis filter,

3. US Patent No. 5,246,586. 1993, apparatus and method for the production of ultrapure water,

4. RF application No. 2001105178/12, 2001, Water purification method and membrane installation for its implementation (prototype).

Claims (3)

1. Membrane filter for water purification, containing a membrane for reverse osmosis, located in a separate housing equipped with an inlet and two outlet, one of which is designed to remove drainage water, and the other to dispense purified water, as well as a pre-treatment device containing a filter purification from mechanical impurities and an activated carbon filter, characterized in that the membrane filter is equipped with an additional water treatment unit installed at the entrance to the membrane housing and containing installed, an ion-exchange microglobular filter containing silver, a liquid polyhexamethylene guanidine dispenser made in the form of a capsule with microscopic holes and a polyphosphate dispenser made in the form of a container with porous walls containing polyphosphate in the solid state, both dispensers installed in the stream of purified water . 2. The membrane filter for water purification according to claim 1, characterized in that the diameter of the holes of the capsules of the dispenser of the liquid polyhexamethylene guanidine is 0.01-0.25 mm, an air outlet is made in the upper part. 3. The membrane filter for water purification according to claim 1, characterized in that the pore diameter of the capacity of the polyphosphate dispenser is 0.15-1.2 mm.