RU2179163C2 - Method and apparatus for concentrating humin acid salt solutions - Google Patents

Abstract

FIELD: chemical engineering. SUBSTANCE: concentration of solutions is accomplished by formation of liquid film on the outside surface of hollow drum, which is then concentrated when being heated by a heat carrier until concentration of humin acids at least 21%. Each concentrated layer is removed from drum, packaged hot, and then cooled to ambient temperature. Apparatus has casing, hollow rotary drum with electric drive disposed at the level of casing edge and oriented along horizontal axis, housing- protected hot fan for supplying heat carrier onto outside drum surface, and also casing-mounted liquid layer-removal device. EFFECT: enabled formation of humin acid salts in the form of high-concentration gel, which is advantageous for storage and transportation. 2 cl, 1 dwg, 1 tbl, 4 ex

Description

 The invention relates to the field of concentration of liquids by creating a liquid film on a heated surface and can be used to obtain concentrated salts of humic acids.

 A known method of concentrating liquids, patent N 2067016, CL. In 01 D 1/22, according to which the film created by the blades of a rotating rotor is evenly distributed on the inner surface of the housing, it is evaporated, while the volatile component evaporates from the film. The thickened product and the vapor of the volatile component move in the same direction with equal speeds along the guide surface with their subsequent separation. The ratio of thickened and volatile product is maintained within 2-30. The disadvantage of this method is the difficulty of maintaining process parameters and, therefore, the implementation of technology in production.

 There is also known a method of concentrating a liquid according to patent N 2060764, class. In 01 D 1/22, according to which the solution is distributed on the inner surface of the reactor (hollow drum) in the form of a film and under the action of a heat carrier bubbling through the film, the evaporated moisture is separated and removed from the apparatus. In this method, there is a significant heating of the liquid with local temperature jumps up to 1000 degrees. The disadvantage of this method is the heating of the liquid to a high temperature and the formation of stable foam during the bubbling of the coolant through the film.

The closest technical solution, in comparison with the claimed, is a method of obtaining a plant growth stimulator according to the patent of the Russian Federation N 2007376, class. C 05 F 11/00. According to this method, a liquid containing humic acids and obtained by processing humate-containing substances with alkaline solutions is treated with a solution of nitrogen-containing salts and the resulting product is evaporated in a spray dryer at a temperature of 130 ^o and granules with a moisture content of 7% are obtained.

 The disadvantage of this method is that when using the technology according to patent N 2007376 it is impossible to obtain a solution of salts of humic acids in the form of a gel.

 Salts of humic acids are high-molecular polyfunctional compounds (molecular weight up to 1500 cu) and are prone to aggregation, which leads to the formation of aggregates with a molecular weight of up to 400000 cu Such aggregates are characterized by an extremely low diffusion rate and, due to multifunctionality, a high affinity for water. In this regard, the evaporation of such solutions in closed containers is extremely slow, especially since it is undesirable to bring the solution of humic acid salts to a boil due to a partial loss of the biological activity of humates, since this leads to a deterioration in their basic quality - stimulation of plant growth.

 A device for concentrating humic acids, which has common features with the claimed, was not detected.

 Solutions of salts of humic acids, used as a plant growth regulator and in a number of technical fields, are produced in the form of dilute solutions, the concentration of which is usually 4-7%. The packing, storage and transportation of such solutions over long distances, especially at negative air temperatures, is associated with large additional costs. These circumstances determine the need to concentrate solutions of salts of humic acids to such an extent as to deprive them of fluidity and provide the ability not to freeze at low air temperatures.

 An object of the invention is the creation of a method and device that allows for the production of concentrated solutions of salts of humic acids, which have the property in the cooling process to spontaneously form a gel with a complete loss of fluidity.

 The task is achieved by the fact that a hollow drum is immersed in a solution of salts of humic acids and rotated to form a film on the outer surface of the film, exposing it from the outside to a directed flow of hot air and removing each layer of the film treated with the coolant from the drum. The rotation of the drum is carried out until the concentration of salts of humic acids in the solution is at least 21%. The resulting concentrate is poured into containers and cooled at ambient temperature until gelation with complete loss of fluidity.

 The device for implementing the method comprises a reservoir with a nozzle for supplying a solution and placed inside the rotor in the form of a hollow drive drum mounted on the horizontal axis of the reservoir, the axis being mounted on the upper edge of the reservoir, an air fan installed to heat the outer surface of the drum protruding from the reservoir and a unit for removing the heat-treated film mounted on the tank body.

 In connection with the above-mentioned features of the behavior of humic acid salts during concentration (low diffusion rate, tendency to aggregate, and high affinity for water) upon evaporation of moisture from the reservoir, a film with a high concentration of salts is formed on the surface of such solutions, which prevents further evaporation. Due to the fact that in the present invention, the thickness of the film of humic acid salts formed on the drum surface is very small, evaporation of moisture from it occurs throughout the entire thickness, and since each layer of the film processed by the heat transfer medium is cut off, each subsequent film layer formed on the drum is also removed moisture throughout its thickness. This allows for effective concentration of solutions of salts of humic acids, taking into account the structural features.

 Due to the fact that the drum is immersed in a solution of salts of humic acids during rotation, a thin layer of solution sticks to its surface, and a fan heater installed above the drum with the possibility of heating the drum part protruding from the housing as it rotates removes moisture from the film, the salt solution on the drum reaches the desired concentration . The presence of a unit for removing the film-layer processed by the coolant allows rotating the drum to form the next layer on its surface with the initial concentration of humic acid salts, which acquires the desired concentration in the flow of hot air from the fan heater. This process proceeds continuously at a constant level of solution in the tank.

 Thus, the proposed method and device meet the criterion of "inventive step".

 The invention is illustrated in the drawing, which shows a device for a concentrated solution.

 The device includes a reservoir 1 in the form of a rectangular housing 2, mounted on the housing 2 by the axis 3, a rotor in the form of a hollow drum 4, equipped with a rotation drive 5. The axis 3 of the drum 4 is located on the upper edge of the housing 2. The housing 2 is equipped with a pipe 6 for continuous fluid supply and a knife 7 with a tray 8 is installed in the housing for removing the heat-treated film from the drum and a pipe 9 for removing the concentrated solution. The drive 5 consists of an electric motor and a gearbox providing the drum rotation speed necessary for concentrating the liquid film during heating to the desired content of the main component. The rotation speed of the drum depends on the initial concentration of the solution. The device is equipped with a sensor for the level of the solution in the tank (not shown in the drawing). An air heater 10 is installed over the drum 4 part protruding from the housing 2 and is located in the housing 11 in the form of a cone covering the drum 4 protruding from the housing 2. The concentrated liquid from the tray 8 enters a filling machine (not shown).

 The device operates as follows.

 The tank 1 through the pipe 6 is filled with a solution of salts of humic acids, which subsequently continuously enters the tank as it is spent. Then, depending on the concentration, a predetermined speed of rotation of the drum 4 is set and at the same time the drive 5 of the drum 4 and the fan heater 10 are turned on. The solution during rotation of the drum 4 sticks in the form of a film onto its outer surface. In the housing 11, the film is heat treated, partial evaporation of moisture from it, and the concentration of humic acid salts in the film are concentrated. Evaporated moisture leaves together with the effluent of the coolant. The heat-treated film layer is removed from the drum 4 with a knife 7 and along the tray 8 through the pipe 9 immediately spills hot in the packaging containers, where it is cooled.

 The method is illustrated by the following examples.

 Example 1

 A solution of sodium humate with a concentration of 13.3% was loaded into the container, at the same time the coolant and the drum were turned on. The drum speed was set at 15 revolutions per hour. On the canvas of the drum during its rotation, a solution film is formed, which is subjected to heat treatment as the drum passes in the coolant zone at a temperature of 36-40 degrees. After heat treatment, the film was removed from the drum web with a knife and collected in a container, then immediately poured into the packaging container and analyzed for the content of salts of humic acids. Cooling and determination of gelation time was carried out at ambient temperature. The same was done at a drum speed of 10 revolutions per hour.

 Examples 2,3,4.

 Analogously to example 1, the process was carried out using solutions of salts of humic acids with a concentration of 16.0-17%, 18-19% and 19-20%, using various speeds of rotation of the drum. The experimental results are shown in the table.

 The rotation speed of the drum depends on the initial concentration of solutions of salts of humic acids and was selected experimentally until the content of salts of humic acids in the final solution is at least 21%.

 As can be seen from the table, when the concentration of the solution of salts of humic acids is from 13 to 14%, the required drum rotation speed to obtain the desired properties of the solution is 10 vol. / Hour, at 16-17% - 10-15 vol. / Hour, at 18-19 % from 10 to 20 vol. / hour, with 19-20% from 10 to 40 vol. / hour. It was experimentally determined that under these conditions, the solution of salts of humic acids reaches concentrations at which it turns into a gel with a complete loss of fluidity within 6.2 hours, 2.3 hours and 3 hours, respectively.

 Thus, the proposed method and device for its implementation allows to obtain salts of humic acids in the form of a gel (humagel).

 Humagel is a highly concentrated product, convenient for storage and transportation. It completely retains its properties at temperatures up to minus 20 degrees C and, if necessary, reverts to a fluid state when heated to a temperature of 30-35 degrees C.

Claims (2)

 1. The method of concentration of solutions of salts of humic acids by evaporation under the influence of a coolant, characterized in that the evaporation is carried out by forming a liquid film of a solution of salts of humic acids on the outer surface of a hollow drum when exposed to an air flow of a coolant to a concentration of salts of humic acids of at least 21%, each the heat-treated film layer is removed from the surface, packaged hot in a container and cooled at ambient temperature.  2. A device for concentrating solutions of salts of humic acids, comprising a housing, a rotor in it in the form of a hollow drum mounted on the horizontal axis of the housing with its heating source, a drum drive and a fluid supply pipe, the rotor axis being placed on the housing, and as a fan heater is installed with the possibility of heating the part of the rotor protruding from the housing; in addition, a unit for removing concentrated liquid from the rotor surface is installed on the housing.

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