RU2404132C2 - Water purification method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves freezing water and thawing the ice in the same vessel, wherein during thawing, a first portion of pure water obtained from the outer layer of ice flows under gravity through an overflow opening in the side wall of the vessel. Water containing salts, impurities and a precipitate, obtained from the inner part of the ice which is last to thaw, remains in the vessel lower than the level of the overflow opening. On the side wall of the vessel there is one or more overflow openings at a level corresponding to 60-90% of the volume of the vessel and the vessel is turned over before the thawing process.

EFFECT: simple process of obtaining pure water with low content of mineral salts.

2 dwg, 1 tbl

Description

The invention relates to the field of water purification while giving it the properties of melt water and can be used in food, pharmaceutical, medical industry and in everyday life.

A known method of water purification [A method of obtaining high-quality drinking water with a reduced concentration of dissolved salts and improved structure of water enriched with oxygen, by the method of wall crystallization. Application 2005126970. Russia. IPC C02F 1/22 / Glazunov V.G. Claim 2005.08.26, publ. 2007.03.10], in which the influence of negative temperatures from the side of the vessel walls is carried out until the formation of clean and transparent ice on the vessel walls, after which the brine is poured, and the ice remaining on the vessel walls is melted and used as water with a reduced concentration of dissolved salts with improved structure water.

The disadvantage of this method is that during the cleaning process it is necessary to control the interruption time of the freezing process to perform the operation of draining the water.

Closest to the proposed method is a method of water purification [Method of improving the quality of drinking water by freezing and thawing / Pat. 2186033. Polezhaev Yu.M., Rusinova A.A. Application 2001109787/12. Claim 2001.04.11, publ. 2002.07.27], in which the source water is frozen in a vessel with a height to linear cross-sectional dimension of ≥2, ice is melted in the same vessel at a temperature of up to 30 ° C and the upper purified liquid layer with a volume of ≤75% of the total volume of frozen water, drained (siphon), while thawing is carried out so that the vessel is stationary in an upright position, and the drained water is drained no later than one day after the end of thawing.

The disadvantage of this method is the complex operation of siphoning without violating the steady gradient of the concentration of the solution, as well as the need to ensure the immobility of the vessel throughout the time from the beginning of the process of melting ice to the process of siphoning.

The objective of the invention is to simplify the process of separating water into pure and containing an increased concentration of salts and impurities.

The following method and device for water purification. It is proposed to freeze water in a vessel in the side wall of which an overflow hole is made. Before the process of melting ice, the vessel is turned over. When ice is thawing, the first portion of clean water of a given volume flows by gravity from the vessel through the overflow hole as the outer layers of ice are thawed. Water with a high concentration of salts and sediment remain in the vessel below the level of the hole. The fraction of the volume of pure water from the total volume of the frozen water to be cleaned, which means that the degree of water purification is determined by the height of the overflow hole.

The proposed method of water purification by freezing is based on the fact that the freezing temperature of aqueous solutions is lower than the freezing temperature of pure water (0 ° C). When water freezes in a vessel under the influence of negative temperatures from the side of the vessel walls, the outer layers of more pure water are first frozen. With further cooling, the deeper, inner layers of water in the vessel, which have an increasingly high concentration of dissolved substances, freeze. Thus, during freezing, spontaneous separation of water into layers with different concentrations of dissolved substances occurs. In the process of ice thawing when heat is supplied from the side of the vessel walls, the outer layers of ice begin to melt, forming clean melt water.

The method can also be used to increase the concentration of solutions.

Figure 1 shows a first embodiment of a device for implementing the proposed method. The device contains a vessel (1), in the side wall of which one or more overflow openings (2) are made at a level corresponding to 60-90% of the volume of the vessel (1). Depending on the location of the overflow holes, the degree of water purification changes. The water to be purified is poured into the vessel (1) to the level of the overflow hole (2) and completely frozen. Before the process of ice melting, the vessel (1) is turned over. When ice melts, the first portion of pure water, obtained from the outer layer of ice and having the properties of melt water, with a volume of 30-90% of the total volume of frozen water, flows by gravity from the overflow hole (2) in the side wall of the vessel (1) and is used for its intended purpose. In this case, water containing salts, impurities and precipitated precipitate, obtained from the inner part of the ice, melted last, remains in the vessel (1) below the level of the overflow hole (2).

Figure 2 shows a second variant of the device for implementing the proposed method. One or more overflow openings (2) are also made in the vessel (1) at a level corresponding to 60-90% of the volume of the vessel (1). For the convenience of filling the water to be purified in the upper part of the vessel (1), a filler neck (3) is made, onto which a plug (4) is installed.

To verify the proposed method and the operation of the device, a series of experiments were conducted with various shapes and volumes of the vessel, the size and location of overflow openings. The modes of freezing and thawing were checked. The experiments were carried out with tap and artesian water, as well as with solutions of sodium chloride, sugar, baking soda and potassium permanganate solution. Qualitative results were obtained on water treatment in a wide range of design and technological parameters. Water with improved organoleptic properties was obtained stably.

In the bacteriological laboratory, analyzes of the source water and water purified by this method were carried out. The results are shown in the table. The table shows that the proposed method provides a significant reduction in salt content.

Table No. Name of samples MPC, no more Source water Purified water one Total salinity (dry residue), mg / l 1000 490 156 2 Iron, mg / L 0.3 0.13 0.09 3 Chlorides, mg / L 350 46 25 four Sulfates (SO ₄ ^2- ), mg / l 500 77 32 5 Hardness, mmol / l 7.0 8.3 2.6

Claims (1)

A method of water purification, including freezing water and melting ice in the same vessel, in which, when the ice melts, the first portion of pure water obtained from the outer layer of ice flows by gravity from the overflow hole in the side wall of the vessel, and the water containing salts, impurities and the precipitate formed from the inside of the ice, melted last, remains in the vessel below the level of the overflow hole, characterized in that on the side wall of the vessel one or more overflow openings are made at a level corresponding to 60-90% of the volume of the vessel, and before the process of ice melting, the vessel is turned over.

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