RU2221201C2 - Liquid freezing device - Google Patents

Abstract

FIELD: liquid freezing equipment, ice decontamination equipment, water desalination equipment, production of water-soluble substances for domestic and industrial demands. SUBSTANCE: device has vessel filled with still liquid, lid having tubular two-layer member. Tubular member lower end is disposed in non-freezing area of liquid. Tubular member upper end is located above lid. EFFECT: increased product quality by food ice cleaning of detrimental impurities during freezing process without increase of electric power; simultaneous producing of fresh water and sea salt with using of cooling plant waste energy for sea salt production. 2 dwg

Description

 The invention is intended for the separation of liquids into fractions with different concentrations of substances dissolved in it and can be used to clean ice from harmful impurities when desalinating water and obtaining soluble substances in liquids for domestic and industrial needs.

 Known methods of freezing water, in which the water is cooled to ice [1, p.449-467].

 To reduce the concentration of substances in water in ice, water is distilled before freezing, boiled, or water is set in motion during freezing and its impurities are sucked out from the center, or impurities are washed off the ice surface during water circulation [1, p. 450].

 When obtaining ice from distilled water, increased time and thermal energy are required to heat the water to a boil and turn it into steam.

When obtaining ice from boiled water, additional time and thermal energy are required to heat the water to a boil. At the same time, microorganisms and impurities with a boiling point below 100 ^o C are destroyed in water, but the soluble salts in it are not removed.

 When ensuring the movement of water during the freezing process to remove impurities, additional energy costs are required to organize the flow of water and increased water consumption for the removal of impurities.

 The closest technical solution to the invention is a method of freezing drinking tap water, in which a container with still water is cooled externally until ice forms in the freezer of a home refrigerator [1, p. 466 (prototype)].

 With this method, minimal energy is required to produce edible ice and excludes the cost of delivering ice to the consumer, storage of ice and its loss during transportation and storage.

 However, when implementing this method, the substances contained in the water are not removed. In some cases, the concentration of these substances exceeds the maximum permissible values, for example, during overloads of equipment for physicochemical treatment of drinking tap water in ecologically unfavorable areas, during floods or floods.

 The purpose of the invention is the reduction of time and energy for separating the liquid into fractions with different concentrations of soluble substances in it.

 To do this, when implementing the known method of freezing water, in which a container with a stationary liquid is cooled externally until ice forms in it, during the freezing process, part of the unfrozen liquid is squeezed out of the central part outside the container.

 In addition, to reduce the concentration of substances in ice, the liquid after freezing is heated until the ice has completely melted, then it is frozen again.

 To implement the method, the known device containing a container filled with a stationary liquid is provided with a lid and a tubular element installed in it. The bottom end of this element is located in the zone of unfrozen liquid, and the top above the cover.

 To reduce the resistance to the withdrawal of unfrozen liquid through the tubular element and the removal of ice from the tank, the tubular element is made two-layer. The inner layer of this element is made of material with a smaller, and the outer one, with a larger thermal conductivity than ice.

 To increase the amount of discharged unfrozen liquid with a high concentration of substances, the lower section of the tubular element is perforated.

 To exclude transportation costs and ice losses during transportation and storage or to increase the concentration of substances in unfrozen liquids by producing ice at the place of its consumption or lowering the ice temperature when placing the device in the freezer, the device is equipped with thermoelectric batteries placed on the outer surface of the container and lid with cold and hot junctions, on which heat exchangers are installed on the opposite side from the tank and the lid.

 To ensure freezing of the upper liquid layer during repeated freezing, to increase the freezing rate and to facilitate ice crushing, the lid on the side of the tank is made with ribbing.

 To increase the cooling efficiency of the upper liquid layer in the tank and increase the drying rate of the concentrated solution of substances when placing the device in an environment with positive temperatures, the heat exchanger placed on the cover of thermoelectric batteries is made in the form of a tank open on top.

 To increase the speed of freezing and facilitate the crushing of ice, the container on the inside is made with fins.

 The invention is based on the dependence of the solubility of substances in a liquid on its temperature and pressure and on the increase in the volume of water during its freezing.

The drawing schematically shows examples of a device for implementing the method:
- figure 1 shows a device for cleaning food ice in the freezer;
- in FIG. 2 - a device with thermoelectric batteries mounted on a container and a lid.

 The device contains (Fig. 1) a tank 1 filled with still water with a cover 2, which is made with fins 3. A two-layer tubular element is installed in the cover 2. The bottom end of this element is located in the area of unfrozen liquid, and the top above the cover. The outer layer of the tubular element is made of aluminum tube 4, and the inner one is made of fluoroplastic tube 5. The lower portion of the tubular element is perforated in the form of holes 6. The device can be installed in the freezer 7, for example, a home refrigerator.

 Thermoelectric batteries 8 with cold and hot junctions are placed on the outer surface of the container 1 and the cover 2 (FIG. 2), on which heat exchangers 9 are installed on the sides of the container 1 and the cover 2. The heat exchangers of the thermoelectric batteries placed on the container 1 are made in the form of a needle or lamellar fins 10, and placed on the lid 2 - in the form of a container open at the top 11. The device can be mounted on a stand 12. In addition, the tank 1 from the inside can be made with a ribbing 13.

 An aqueous solution of any water-soluble substance can also be used as water.

 As materials of the tubular element, any other ones can also be used that satisfy the condition of performing the inner layer with a smaller and the outer layer with a larger thermal conductivity than ice.

 The number of holes 6 may also be any other.

 Any other medium with a negative temperature can also be used as a freezer 7.

 The design of heat exchangers 9 and fins 3 and 13 can be any other.

 In the process of cooling the outer surfaces of the container 1 and the cover 2 until ice forms in the container 1, a temperature difference appears between the layers adjacent to the walls of the container 1 and the cover 2 and the central part of the water. As a result, the concentration of substances dissolved in water in the layers adjacent to the walls of the container 1 and the lid 2 decreases, and increases in the central part. Ice begins to form around the periphery of the tank and seals the unfrozen central part of the water. As the thickness of the ice increases, its volume increases, the pressure of unfrozen water and the concentration of substances dissolved in it increase, and it is squeezed out of the container 1 to the cover 2 through the lower end of the tube 5 and hole 6. Due to the heat-insulating properties of the ice and the material of the tube 5, the liquid in it freezes last. This is facilitated by an increased concentration of substances in the unfrozen central part of the water.

 After freezing the entire volume of water, the device is removed from the chamber 7 and heated at a positive ambient temperature, or doused with tap or hot water. When the surfaces of the ice and the tube 4 reach the melting temperature of the ice, the lid 2 is opened, and the ice is removed and used for its intended purpose.

 If necessary, a higher degree of purification of food ice, it is frozen to a lower temperature or after complete melting of the ice in the tank 1, the freezing is repeated.

 With repeated freezing, the water level in the tank 1 decreases, and the upper layers of the water are cooled through the fins 3 of the lid 2.

 In the device shown in figure 2, the cooling of the tank is carried out using a thermoelectric refrigeration unit. The heating of the device for the extraction of ice or its melting is carried out by changing the polarity of the electric current supplied to the thermoelectric batteries 8. When cooling, the cold junctions of the batteries 8 are adjacent to the surface of the tank 1 and cover 2, and when heated, to the heat exchangers 9 and 11.

 The concentrated solution is drained in the tank 11 both during the period of freezing water and after removing the cover 2 from the tank 1, using the thermal energy released by thermoelectric batteries. Otherwise, the principle of operation is similar to that considered for the device shown in Fig.1.

 A positive effect from the use of the invention is achieved by expanding the functionality of refrigeration equipment, which is used both for cooling and separating the liquid into fractions with different concentrations of dissolved substances in it at a lower cost, compared with the prototype, time and energy. This allows, for example, in the production of edible ice to improve the quality of products by cleaning ice from harmful impurities during the freezing process or when desalinating, for example, sea water while producing fresh water and sea salt with less time and energy, due to the use of sea salt waste heat energy of the refrigeration unit.

Sources of information
1. Refrigeration: Encyclopedic reference book in 3 volumes. Volume 2. The use of cold in industry and transport. - M.: Gostorgizdat, 1961.

Claims (1)

A device for freezing a liquid, comprising a container for filling with a stationary liquid, provided with a lid with a tubular element installed in it, the upper end of which is located above the lid, characterized in that the element is two-layer, and the tubular inner layer is made of material with a smaller one and the outer one with a large than ice, the value of the coefficient of thermal conductivity, while the lower end of the tubular element is located in the tank in the zone of the central non-freezing part of the liquid, and the lower section of the tubular ementa perforated.

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