Foam separation device and foam separation method

Abstract

To provide a foam separation device and a foam separation method that can improve the concentration ratio of a substance to be separated.SOLUTION: A foam separation device 1 comprises a separation column 2, a solution supply part 3 that supplies a solution comprising a surface-active substance into the separation column 2, and a gas supply part 4 that supplies a gas into the separation column 2 and generates foam from the solution. The separation column 2 is provided with notches 25 that communicate between the inside and outside of the separation column 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a foam separation apparatus and a foam separation method. [Background technology]

[0002] A foam separation device is known that blows gas into a solution containing a surfactant to generate foam (sometimes called foam liquid), and separates the material to be separated by adsorbing it onto the surface of the foam (see, for example, Patent Document 1).

[0003] Foam separators have the advantages of being simple in structure and operation, low in manufacturing and running costs, and low environmental impact. For these reasons, foam separators are used in a variety of fields, including copper flotation, the concentrated removal of toner and oil-based ink dispersed in paper solvents (deinking), the removal of proteins from skin mucus in fish breeding and aquaculture, and for protein separation in the food and pharmaceutical industries. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-272113 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional foam separation devices such as those described in Patent Document 1, there was no technology for improving the concentration ratio of the substance to be separated in the foam.

[0006] An object of the present invention is to provide a foam separation apparatus and a foam separation method that can improve the concentration ratio of a substance to be separated. [Means for solving the problem]

[0007] The foam separation device of the present invention comprises a separation tower, a solution supply section that supplies a solution containing a surfactant into the separation tower, and a gas supply section that supplies gas into the separation tower and generates foam from the solution, and is characterized in that the separation tower is provided with a notch that connects the inside and outside of the separation tower.

[0008] According to the present invention, the separation tower is provided with a slit that connects the inside and outside of the separation tower, so that the slit allows drainage to be performed outside the separation tower, thereby improving the concentration ratio of the substance to be separated. The concentration ratio of the substance to be separated is the concentration of the substance to be separated in the foam divided by the concentration of the substance to be separated in the solution supplied to the separation tower (concentration ratio of the substance to be separated = concentration of the substance to be separated in the foam ÷ concentration of the substance to be separated in the solution supplied to the separation tower).

[0009] In the foam separation apparatus of the present invention, it is preferable that a plurality of the notches are provided, and that the notches located lower are formed longer than the notches located upper.

[0010] According to the present invention, the lower notches are formed longer than the upper notches, so that the lower notches can promote drainage from the lower foam, which has a higher water content.

[0011] The foam separation method of the present invention is characterized by carrying out a step of supplying a solution containing a surfactant into a separation tower provided with a slit connecting the inside and outside of the separation tower, and a step of supplying a gas into the separation tower to generate foam from the solution.

[0012] According to the present invention, the same effects as those of the foam separation device described above can be obtained. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of a foam separation device according to one embodiment of the present invention. [Figure 2] FIG. 4 is a schematic diagram of a foam separation device according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below with reference to FIG. In the following description, directions are indicated based on the state in which the foam separation device 1 is arranged as shown in FIG.

[0015] The foam fractionator 1 is a device that separates a substance to be separated from a solution containing a surfactant having surface activity and the substance to be separated. Here, surfactant can be mentioned as surface active substance.Surfactant is a substance that has hydrophilic group and lipophilic group, for example, can be anionic surfactant such as aliphatic salts, higher alcohol sulfate salts, liquid fatty oil sulfate salts, sulfate salts of aliphatic amine and aliphatic amide, fatty alcohol phosphate salts, sulfonic acid salts of dibasic fatty acid ester, fatty acid amide sulfonic acid salts, alkyl aryl sulfonic acid salts, formalin condensed naphthalene sulfonic acid, etc., cationic surfactant such as fatty amines, quaternary ammonium salts, alkyl pyridinium salt, etc., nonionic surfactant such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, etc., amphoteric surfactant, but not particularly limited. In addition, surface-active substances other than surfactants include, for example, proteins, phenols, anionic, cationic, and nonionic synthetic surfactants, fatty acids, polyhydric alcohols, etc., which themselves can be separated as substances to be separated. The solvent for the solution may be, for example, water, alcohol, or a mixture thereof.

[0016] The foam separation device 1 includes a separation tower 2, a solution supply section 3, a gas supply section 4, and a residual liquid recovery section 5.

[0017] The separation tower 2 is a cylindrical member made of a transparent or translucent material such as glass or plastic, and has a hollow interior. The separation tower 2 has a gas supply port 21 and a residual liquid recovery port 22, each provided at the lower end, a foam recovery port 23 provided at the upper end, a solution supply port 24 provided on the side, and a plurality of notches 25 provided on the side above the solution supply port 24. The notches 25 are provided at a position above the liquid level FL of the solution supplied into the separation tower 2, and penetrate the side wall of the separation tower 2 to communicate between the inside and outside of the separation tower 2. Each notch 25 has a linear shape extending in the vertical direction, and these notches 25 are lined up in a straight line in the vertical direction to form multiple rows.

[0018] In this embodiment, the separation tower 2 is formed by shaping a resin film or plate into a cylindrical shape. The cross section of the notch 25 is tapered, with the width (thickness) of the notch 25 narrowing on the inner wall surface side of the separation tower 2 and widening on the outer wall surface side of the separation tower 2. If the height (length) of the separation tower 2 is several hundred mm, the notch 25 has a maximum length of 100 mm. For example, if the height of the separation tower 2 is 800 mm and the diameter is 30 mm, the notch 25 is provided in a range of 200 to 600 mm from the bottom end of the separation tower 2, and each notch 25 has a length of 5 to 30 mm. The width of the notch 25 is large enough to allow capillary force to act on the inner wall surface side of the separation tower 2, and is, for example, several tens to several hundreds of μm.

[0019] The solution supply unit 3 includes a solution storage unit 31 such as a tank for storing a solution, a pump 33 connected to the solution storage unit 31 via piping 32, and piping 34 connecting the pump 33 to the solution supply port 24.

[0020] The gas supply unit 4 includes a gas storage unit 41 such as a tank or gas cylinder that stores a gas such as nitrogen gas or argon gas, a pump 43 connected to the gas storage unit 41 via piping 42, a piping 44 connected to the pump 43 and inserted into the gas supply port 21, and a disperser 45 provided at the end of the piping 44 and arranged inside the separation tower 2. The disperser 45 is composed of a porous filter made of glass, metal, ceramic, plastic, resin, or the like, such as a glass filter, so-called air stone, or wood stone.

[0021] The residual liquid recovery section 5 includes a pipe 51 connected to the residual liquid recovery port 22 and a water level adjuster 52 connected to the pipe 51, and recovers the residual liquid remaining in the separation column 2.

[0022] A method for separating the target substance using the foam fractionator 1 described above will now be described. First, a solution is supplied from the solution storage section 31 to the separation column 2 by the pump 33. Next, gas is supplied from the gas storage section 41 to the separation column 2 by the pump 43, dispersed by the disperser 45, and blown into the solution in the separation column 2. The gas blown into the solution becomes bubbles AB. If the target substance is a surfactant, the target substance adsorbs to the surface of the bubbles AB, which is the gas-liquid interface. If the target substance is not a surfactant, the target substance adsorbs to the surfactant adsorbed on the surface of the bubbles AB and moves upward in the solution. The bubbles AB then rise in the solution, become foam BL, separate from the liquid surface FL of the solution, and rise with the target substance still adsorbed to them, and are collected from the foam collection port 23. The remaining liquid in the separation column 2 is collected through the water level regulator 52.

[0023] Here, because the separation tower 2 is provided with the notches 25, while the foam BL rises, the solution contained in the foam BL is not only drained from the foam BL by its own weight and falls within the separation tower 2, but also drained from the foam BL to the outside of the separation tower 2 through the notches 25. This makes it possible to improve the concentration ratio of the substance to be separated in the recovered foam BL compared to conventional devices. As an example of foam separation using the foam fractionator 1, foam separation was performed using the foam fractionator 1 and a conventional device not provided with the notches 25, with protein as the substance to be separated from a solution in which skim milk powder was dissolved in water. The foam fractionator 1 showed a protein concentration ratio that was approximately 1.4 times higher than that of the conventional device.

[0024] According to the above embodiment, the separation tower 2 is provided with a notch 25 that connects the inside and outside of the separation tower 2, and the notch 25 allows drainage to be performed outside the separation tower 2, thereby improving the concentration ratio of the substance to be separated.

[0025] As described above, the best configurations, methods, and the like for implementing the present invention have been disclosed in the above description, but the present invention is not limited thereto. That is, although the present invention has been particularly illustrated and described mainly with reference to specific embodiments, those skilled in the art can make various modifications to the above-described embodiments in terms of shape, material, quantity, and other detailed configurations without departing from the scope of the technical idea and purpose of the present invention. Furthermore, the above-disclosed descriptions limiting the shape, material, and the like are provided as examples to facilitate understanding of the present invention and are not intended to limit the present invention. Therefore, descriptions using names of components that are free from some or all of the limitations on shape, material, and the like are included in the present invention.

[0026] For example, the separation tower 2 may be formed of a transparent or translucent material, or may be formed of an opaque material, or may be formed of a metal, ceramic, or the like, and the material, height, diameter, and other dimensions of the separation tower 2 are not particularly limited. The separation column 2 may have a plurality of cuts 25 of different lengths. The lower notches 25 may be longer than the upper notches 25. For example, as shown in FIG. 2, the lower the notches 25 are, the longer they are. Alternatively, the area in the separation tower 2 where the notches 25 are formed may be divided into two, upper and lower, and the notches 25 in the lower area may be longer than the notches 25 in the upper area. The notches 25 may be formed in greater numbers at the upper part of the separation tower 2 than at the lower part; for example, the more notches 25 are formed toward the upper part of the separation tower 2, or the area in which the notches 25 are formed in the separation tower 2 may be divided into two parts, upper and lower, and the number of notches 25 located in the upper area may be greater than the number of notches 25 located in the lower area. The notches 25 may be provided over the entire circumferential direction of the side surface of the separation tower 2, or may be provided in a partial region in the circumferential direction. The shape and number of the notches 25 are not particularly limited, and the notches 25 may be formed in any shape, such as a linear shape extending in the left-right direction, a linear shape extending in a direction perpendicular to the up-down and left-right directions, a waveform shape such as a sine wave or rectangular wave extending in the up-down or left-right direction, a circle, an arc shape that is convex upward or downward, a polygon, a cross shape, a V shape that is convex upward or downward, a U shape that is convex upward or downward, etc., and there may be one or more notches 25.

[0027] The gas supply unit 4 may be provided with, for example, a self-suction air ejector having a Venturi tube instead of or in combination with the disperser 45, and the bubbles AB may be generated by the ejector. The gas supplied by the gas supply unit 4 may or may not be an inert gas. The distributor 45 may be provided detachably on the pipe 44 . [Explanation of symbols]

[0028] 1...Foam separator, 2...Separation tower, 3...Solution supply section, 4...Gas supply section, 5...Residual liquid recovery section, 25...Slit.

Claims

1. A separation tower; a solution supply unit for supplying a solution containing a surfactant into the separation column; a gas supply unit that supplies a gas into the separation tower to generate foam from the solution; A foam separation apparatus, characterized in that the separation tower is provided with a notch at a position above the liquid level of the solution in the separation tower, which communicates the inside and outside of the separation tower.

2. The cuts are provided in plurality, 2. The foam separation device according to claim 1, wherein the lower notch is longer than the upper notch.

3. A step of supplying a solution containing a surfactant into a separation tower having a notch communicating the inside and outside of the tower at a position above the liquid level; and supplying a gas into the separation tower to generate foam from the solution.

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