JPS61181504A - Method and apparatus for concentrating solution - Google Patents

Abstract

PURPOSE:To concentrate stably and efficiently a soln. and to operate stably a filter for a long period by passing the soln. to be treated through a hollow yarn membrane to concentrate the soln., and then concentrating the soln. to the final concn. by a spiral membrane. CONSTITUTION:An untreated liq. tank 1 is connected to the first filter module 3 provided with a hollow yarn membrane through a circulating and supplying pump 2. The output side of the module 3 is connected to the second filter module 5 furnished with a spiral membrane through another circulating and supplying pump 4. Each module 3 and 5 may be formed in multiple stages when needed. This method is efficiently applied when a liq. such as a protein soln. or syrup whose viscosity increases rapidly with increasing concns. is concentrated by ultrafiltration or reverse osmosis.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method and apparatus for concentrating solutions, such as protein solutions and sugar solutions, whose viscosity increases as the concentration increases, by ultrafiltration or reverse osmosis. It is related to.

BACKGROUND OF THE INVENTION As generally known, concentration by ultrafiltration or reverse osmosis can be accomplished by membrane filtration.9. Since it allows low-molecular solutes and water to pass through without phase change, it saves energy and can be used to concentrate substances that are relatively unstable to heat and pH. From these viewpoints, membrane separation technology has come to be widely applied as a means of concentrating this type of solution in place of evaporation methods and freezing methods. Membrane separation technology can efficiently separate and concentrate dissolved inorganic substances and organic substances, save energy because there is no phase change during the separation process, and furthermore, because it is a non-heating operation, it is possible to efficiently separate and concentrate dissolved inorganic substances and organic substances. It has the advantage that the substance does not undergo thermal denaturation and can be selectively separated and concentrated depending on the molecular weight, structure, and properties of the dissolved substance, but there is a limit to its concentration. is 69. Membrane surface contamination is unavoidable.Membrane module selection and operation management%
There is a problem in that there are restrictions in practical aspects such as membrane cleaning.

By the way, the membrane type is a flat membrane (sheet-like membrane).

There are four types of membranes: spiral membranes, hollow fiber membranes, and tubular membranes, and the one suitable for the liquid to be treated is selected and used. For example, if there are suspended substances or solids in the liquid to be treated, a spiral membrane or hollow fiber membrane may clog the flow path midway through the process, degrading membrane performance. It's advantageous. In the case of g-filtration of a clean liquid, a flat membrane or a tubular membrane increases the size of the device and costs more, so it is advantageous to use a spiral membrane or a hollow fiber membrane.

The purpose of the present invention is to solve the problem of how to efficiently concentrate a liquid such as an IR white bath solution whose viscosity rapidly increases with an increase in 'aM through ultrafiltration and reverse osmosis. .

Therefore, what kind of performance characteristics can be obtained during batch condensation and continuous vlki71 when skimmed milk is concentrated using four types of membrane modules as a pretreatment in the fermented milk and cheese production process? A study of various artists about
I've been conducting experiments. According to the publication, spiral membranes are advantageous when concentrating skim milk to a high concentration of 1-10 times to 10 times, and as low as 10,000 to 3 times the concentration of skim milk. It has been recognized that hollow fiber membranes are good for concentrating. As a result, when concentrating liquids whose viscosity increases rapidly as the concentration increases, such as protein solutions and sugar solutions, hollow fiber membranes are more advantageous than spiral membranes at low concentrations; Finally, it was discovered that a hollow fiber-like membrane makes it difficult for the liquid to flow, and that a snot-like membrane makes it impossible to process the liquid. Figure 2 of the attached drawings illustrates the relationship between solution concentration and filtration rate depending on the membrane type.As can be seen from this figure, with a hollow fiber membrane, the filtration rate decreases rapidly as the solution concentration increases; At a certain concentration level, FA becomes virtually impossible, and in the case of the Mayu spiral membrane, the filtration rate is lower than that of the hollow fiber membrane in the low concentration range, but it decreases relatively gradually up to the high concentration range. Recognize.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for efficiently concentrating a solution by utilizing the transient characteristics of a hollow fiber membrane and a spiral membrane.

Third Means for Solving the Problems In order to achieve the above object, the method for concentrating a solution according to the present invention comprises first passing the solution to be treated through a hollow fiber-like membrane to a predetermined concentration level. The method is characterized in that the thus concentrated solution is subjected to a final concentration process using a spiral membrane.

The apparatus for carrying out this method also comprises a ninth hollow fiber membrane connected to a source of the solution to be treated and concentrated to a predetermined concentration level. %
A second filtration device is connected to the output side of the @/1F' filtration device, and is equipped with a snow sieve-shaped membrane.

Solution to be treated t - 1st. ．． Continuous concentration treatment using an igJ filtration device is indicated as t%.

With this structure, in the present invention, when condensing the melt to be treated, a hollow fiber-like membrane is used to concentrate in the initial relatively low concentration region, and the melt that has been concentrated to this extent can be concentrated. Since the spiral membrane is used to condense the final target device, the concentration process can be carried out extremely efficiently. In other words, by processing in this way, the characteristics of the hollow fiber membrane and spiral membrane used can be fully utilized, and the valley P.
IXt'' can be used stably for a long period of time, resulting in easy maintenance and inspection.
Cleaning work etc. can also be easily performed.

Since the reverse osmosis device is used for specific ultrafiltration by combining a hollow fiber membrane and a spiral membrane, the entire device is continuously stable and can guarantee fc concentration processing.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIG. 7 of the accompanying drawings.

Figure 1 shows the configuration of an apparatus implementing the present invention. Schematically shown is a tank for the stock solution to be processed, which stock tank is connected via a circulating feed pump to a module 3 comprising a hollow fiber membrane. The output 7J side of the module 3 is connected through another circulating feed pump to the module which forms the 2nd filtration device equipped with a spiral membrane.And each of the filtration systems passing through the valley module 3.if is connected to the dotted line. The specific volume module 3.! may be configured in a circulating type as shown in Figure 3.The specific volume module 3.! can also be configured in a multi-stage type as required.Although the illustrated configuration is configured in a continuous type, the method of the present invention can be In actual practice, a filtration system equipped with a hollow fiber membrane and a nine filtration system equipped with a spiral membrane can be constructed separately, and each can be used as a patch system.

Next, a specific example will be explained. Using a three-stage ultrafiltration device, a hollow fiber-like UP membrane 5 is used in the first and second stages.
IP-JO/3 (manufactured by Asahi Kasei Kogyo Co., Ltd.) was incorporated, and the third stage was completely incorporated with a snot-like UF membrane HFK-/J/ (back of Abcor Co., Ltd.), and the protein concentration was 3. /% skim milk was continuously concentrated at a temperature of ≠ 0°C, and after about 7 hours, the stock solution became 1/7t/H% and the concentrated solution became stable, becoming z a t/H.

For comparison, all three stages are hollow fin ζ-shaped UF membrane 5IP.
-30/Ji (manufactured by Asahi Kasei Kogyo Co., Ltd.)) Same treatment as above including high grade? After about 3Q minutes, the pressure drop in the third stage UP' membrane became large and the liquid stopped flowing. So this UF membrane? When it was disassembled, it was found that the hollow fibers were clogged with solid protein.

Effects As explained above, if the present invention is ↓n, is there a membrane suitable for it depending on the concentration stage? Utilize and concentrate? Therefore, the concentration of the solution can be performed stably and efficiently, and as a result, the filtration device used can also be stably operated for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an apparatus implementing the present invention, and FIG. 1 is a graph showing the relationship between bath liquid concentration and offshore overspeed depending on the membrane type. In the figure, l: stock solution tank, λ, r: circulation supply pump, 3.
j: membrane module.

Claims (1)

[Claims] 1. In a method of concentrating a solution by ultrafiltration or reverse osmosis, the solution to be treated is first concentrated to a predetermined concentration level by passing it through a hollow fiber membrane, and then the concentration treatment is performed in this way. A method for concentrating a solution, which comprises passing the solution through a spiral membrane and concentrating it to a final concentration. 2. A first filtration device connected to a supply source of the solution to be treated and equipped with a hollow fiber membrane for concentrating to a predetermined concentration level; and a first filtration device connected to the output side of the first filtration device and equipped with a spiral membrane. 1. An apparatus for concentrating a solution, comprising a second filtration apparatus and a second filtration apparatus, wherein the solution to be treated can be concentrated by connecting the first and second filtration apparatuses.