JPS63182004A - Aqueous solution concentration system - Google Patents

Abstract

PURPOSE:To concentrate an aqueous solution at room temperature and pressure without alteration by causing the aqueous solution to contact a high osmotic pressure liquid via a water-permeable semi-permeable membrane and permitting the high osmotic pressure liquid to circulate after removing its absorbed moisture. CONSTITUTION:A raw material aqueous solution in a storage tank 21 is fed to a head tank 24 through a filter 23, and is maintained at a prearranged temperature by a heater/cooler 24a. Then the solution is fed into a flow path A of a filter press condenser 12 with a semi-permeable membrane and permitted to contact a high osmotic pressure liquid such as cane sugar which passes through a flow path B and a semi-permeable membrane. The concentrated aqueous solution is stored in a finished product storage tank 27. In the meantime, the high osmotic pressure liquid containing an increased quantity of moisture through absorption of moisture from the aqueous solution is sent to a receiving tank 31. Part of the liquid is guided into a regenerator 34 in which the pressure is held at a reduced level by a vacuum pump 33 through a heater 32. The moisture generated in the regenerator 34 is condensed by a cooler 34a and discharged outside of the system. The concentrated high osmotic pressure liquid is recycled to a head tank 36 together with the remainder which is not sent to the regenerator, for circulation into a concentrator 12.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to an aqueous solution concentrating device that can continuously concentrate a large amount of an aqueous solution without heating it, and that can be widely used in the food industry and other industries. .

"Prior Art" Conventionally, as industrial concentration methods for aqueous solutions, evaporation method, reverse osmosis method, limited p-percentivity method, ion exchange method, dialysis method, etc. have been put into practical use.

[Problems to be Solved by the Invention] However, each of the above conventional methods has the following problems.

The evaporation method is a method in which an aqueous solution is heated to evaporate water and separate it from the system, and requires a huge amount of energy for heating and cooling, and deterioration of the quality of the concentrate due to heat is unavoidable.

The reverse osmosis method applies a pressure higher than the osmotic pressure of an aqueous solution to move water molecules against the osmotic pressure. Usually, a pressure of several lθ atmospheres is required, so high-pressure equipment is not required for the equipment. must be used.

The ultrafiltration method is preferably carried out under pressure because the filtration rate is proportional to the pressure, and the mechanical strength of the device is required. Furthermore, it is unavoidable that low molecular weight components move together with water during filtration. A means for removing clogging of the membrane surface is also required.

The ion exchange method separates using electrical energy, and cannot be applied to substances with low ionization, and is mainly used for the removal of inorganic salts and 11wa.

Since the dialysis method separates the aqueous solution and dialysate based on the concentration difference between the components, there are no restrictions on pressure or temperature, but the separation speed is extremely slow, and when handling a large amount of aqueous solution, the size of the equipment is unavoidable.

As a result of intensive research to solve the above-mentioned problems, the present inventors have found that when an aqueous solution and a high osmotic pressure liquid are brought into contact through a water-permeable semi-permeable membrane (hereinafter referred to as a semi-permeable membrane), it is possible to 100
A difference in osmotic pressure of kg/cm' was obtained, and we focused on the phenomenon in which water in an aqueous solution migrates to a high osmotic pressure solution.

The present invention was made using the two-legged phenomenon, and it can be used without applying a large amount of energy such as heating or pressurizing from the outside.
The object of the present invention is to provide a concentrator that can continuously concentrate an aqueous solution at room temperature and under normal pressure.

"Means for Solving the Problems" The present invention has been made to achieve the above object, and its gist is that an aqueous solution and a high osmotic solution are successively introduced,
a concentrator having respective channels for contact and outflow through a water-permeable semipermeable membrane having a large area; a means for feeding the aqueous solution to the concentrator; and a means for feeding the outflowing hyperosmotic liquid to the concentrator. An apparatus for concentrating an aqueous solution is provided, comprising a circulating means and a regenerator for dehydrating at least a portion of the circulating high osmotic fluid under reduced pressure.

"Specific Structure and Effects of the Invention" Since the concentrating device according to the present invention uses a difference in osmotic pressure as the driving force for dehydration, it is possible to limit temperature and pressure (non-toxic).

However, in order to control the dehydration rate, it is necessary to maintain the concentration of the hyperosmotic solution within a certain range. Furthermore, since the type of concentrator is intended to process a large amount of aqueous solution, the semipermeable membrane that partitions the aqueous solution and the high osmotic pressure liquid must have a large area. Therefore, although a spiral type and a shell tube type can also be used, the filter press type is preferable because it has a simple structure and is easy to disassemble and clean.

1 to 3 show an embodiment of an aqueous solution concentrator according to the present invention, and FIG. 1 is a diagram showing a filter press type concentrator in an open state.

Reference numerals 1 and 2 in the figure indicate metal end plates used at both ends of the concentrator. Shallow recesses 4 are provided on the opposing inner surfaces of these end plates, leaving an edge 3 of a predetermined width.

Blind holes are bored near the four corners of the edge 3 of the end plate l. Blind holes 5, 5 near one of these diagonals
Paths 5a, 5a connecting the recessed portions 4 are provided in R, and no path is provided in the blind hole 6.6 near the other diagonal. In addition, in the portion of the end plate 2 facing the blind holes 5 and 6 of the end plate l, through holes 5° and 6
' are bored, and on the outer surface of the end plate 2 of these through holes 5° and 6°, flange pipes 5°a and 5°a for connecting conduits are formed.
A through hole 6'' facing the blind hole 6 is provided with a passage connected to the recess of the end plate 2.

Between the end plates 1.2, there is a gasket 7 that contacts the edge 3 from the end plate l side, a semipermeable membrane 8 that covers the entire surface of the gasket 7, then the gasket 7, and the gasket 7 that forms a space for liquid to pass through. An even number of cell rings 9 having the same shape as the gasket 7 are stacked one after another in order, and the end plate 2 side ends with the gasket 7, the semipermeable membrane 8, the gasket 7, and the end plate 2. These gaskets 7, semipermeable membranes 8, and cell rings 9 have blind holes 5.6.
, through holes 5° and 6' are bored, and a passage 5'°a is formed in the hole 5° of the next cell ring of the end plate 1. As shown, the cell ring 9 is provided with passages 6''a and 5''a every other time, and since there is an even number of passages, passages are provided in the through holes 6'' of the end plate 2. Further, the end plates 1 and 2, the gasket 7, the semipermeable membrane 8, and the cell ring 9 are provided with a large number of holes I and IO through which bolts are passed for overlapping and tightening them. When bolts (not shown) are inserted into these bolt holes 10 and tightened, the above-mentioned parts are crimped together in a liquid-tight manner, and as shown in FIG. As shown in the longitudinal cross-sectional view taken along the dot-dashed cutting line 11, the hole 5'.

5″..., continuous pores a, a consisting of 5, semipermeable membrane 8...
Flow path A1 consisting of every other cavity on one side, continuous holes a, and passages connecting a and the above cavity, and holes 6', 6°...6
A filter press type concentrator 12 is constructed, having a continuous hole B, a passage B, and a flow path B consisting of every other cavity on the other hand.

In this case, the inside of the cell ring 9 and the end plate 1
, 2 may be left as a space, or it is preferable to insert a net-like spacer 13 made of plastic or the like that does not impede the flow of liquid into these parts to maintain a constant spacing between the semipermeable membranes 8. Further, if the total cross-sectional area of the passages provided in the continuous holes a or b is made smaller than the cross-sectional area of the continuous holes a and b, the liquid can be uniformly introduced into each cavity.

As the semipermeable membrane 8 used in the concentrator, a vinylon membrane, a cellophane membrane, an acetyl cellulose membrane, a cellulose acetate membrane, a polysulfone membrane, a polyacrylonitrile membrane, etc. can be used. It needs to be semi-permeable, allowing only water to pass through. Furthermore, the semipermeable membrane is chosen depending on how much it allows substances to migrate with water. In other words, it is desirable to select a semipermeable membrane based on the molecular weight cutoff and its passage. For example, a cellulose acetate membrane has 10 pores, a vinylon membrane has 15 pores, a cellophane membrane has 30 pores, and an acetyl cellulose membrane has 50 pores, and the pore diameter and membrane thickness control the permeation rate and component exclusion rate. Because it does.

FIG. 4 shows an apparatus for concentrating an aqueous solution using the concentrator 12 configured as described above, and reference numeral 21 is a storage tank for raw material aqueous solution.

The aqueous solution in the storage tank 21 is passed through a filter 23 by a pump 22.
and is introduced into the head tank 24 through. The head tank 24 has an overflow pipe 25 that returns the aqueous solution to the storage tank 21.
is provided to maintain the liquid level in the head tank 24 at a constant height. The aqueous solution in the head tank 24 is maintained at a predetermined temperature near normal temperature by a heating/cooling device 24a through which cooling water or heated water flows, and the flow rate is controlled by a flow mFA regulator 26, and the flow rate of the concentrator 12 is controlled. It is introduced from route A (lower flange pipe 5°a). The introduced aqueous solution comes into contact with a high osmotic pressure liquid passing through channel B (described later) via the semipermeable membrane 8, is concentrated, flows out from the outlet of channel A (upper flange pipe 5°a), and enters the product storage tank 27. stored.

This concentrated aqueous solution product is sent to a desired location by a pump 28, but at that time, the concentration level of the product can be controlled by sending a portion of it to the head tank 24 and reconcentrating it as necessary. .

In addition, the high osmotic pressure liquid introduced from the flow path B (lower flange pipe 6°a) passes through flow path B, absorbs water from the aqueous solution through the semipermeable membrane in the process, and absorbs water from the aqueous solution through the semipermeable membrane. Flange pipe 6
It flows out from a). This high osmotic pressure liquid with increased water content is introduced into a receiving tank 31 , and a portion of it is introduced through a heater 32 into a regenerator 34 maintained at a reduced pressure by a vacuum pump 33 .

λ-addition 1 and 2 are heated to compensate for the temperature drop during vacuum concentration of the absorbed hyperosmotic liquid, so any of the double pipe type, shell tube type, plate type, etc. can be used. The moisture evaporated within the regenerator 34 is condensed by the cooler 34a and discharged to the outside of the system. The concentrated high osmotic pressure liquid is sent to the head tank 36 by the pump 35 together with the remaining absorbed high osmotic pressure liquid that was not sent to the regenerator 34 . The high osmotic pressure liquid sent to the head tank 36 is maintained at a concentration from which absorbed water has been removed by adjusting the proportion of the absorbed high osmotic pressure liquid sent to the regenerator 34. Further, the reduced amount of the high osmotic pressure substance that evaporates together with water in the regenerator 34 is replenished from the storage tank 37 to the head tank 36 .

The head tank 36 is equipped with a heating/cooling device 36a, and after being adjusted to a predetermined temperature near normal temperature, the water passes through a flow rate regulator 38 and is circulated to the concentrator 12 at a predetermined flow rate.

In order to increase the water permeation rate of the membrane, there are no restrictions on maintaining the flow rate of the liquid on the membrane surface at a high level, or performing operations such as vibrating or stirring the liquid.

It is also important for food applications to prevent liquid from forming in the system and to create a structure that is easy to clean.

When the aqueous solution to be concentrated is for food use, the high osmotic fluid used in the device of the present invention includes aqueous solutions of edible sugars, such as sucrose, high fructose sugar, glucose, maltose, and fructose, and glycerin, which is a food additive. , propylene glycol, etc. can be used. However, inorganic food additives, such as table salt, calcium chloride, and magnesium chloride, are limited in their use because the hydrated ions have a diameter of only a few inches and there is no semipermeable membrane that completely blocks their permeation. Ru. The relationship between the osmotic pressure and concentration of edible sugars and glycerin is shown in FIG. 5, and a liquid with extremely high osmotic pressure can be obtained.

In applications other than food, there is no need to consider the effects on the human body, so any high osmotic pressure liquid, such as water-soluble organic substances and water-soluble polymers, can be used.

In addition, it is a figure which shows the relationship with the conventional killing method when using a ring of hyperosmotic liquid.

There is no difference in adding a closing operation.

"Effects of the Invention" As described above, the aqueous solution aw6 device according to the present invention has the following features:
At room temperature and pressure, the aqueous solution and hyperosmotic fluid that flow continuously come into contact through a semipermeable membrane with a large area, and the aqueous solution is concentrated and recovered to become a product, and the absorbed water is removed from the hyperosmotic fluid and circulated. does not require a large amount of energy,
In addition, it is possible to efficiently treat aqueous solutions of maggots without altering the aqueous solution, and it can be widely used for concentrating almost all aqueous solutions.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the aqueous solution concentrating device according to the present invention. FIG. 1 is a perspective view showing the filter press type concentrator in an open state, and FIG. A vertical cross-sectional view taken along the dashed line in FIG. 3 after crimping the various parts in FIG. 1;
The figure shows the flow of a concentrator using the concentrator of Figure 2, and Figure 5 shows the concentration and osmotic pressure of food saccharide aqueous solution and glycerin aqueous solution.
...Sewn part, 4...Recessed part, 5...Blind hole, 5a...Passway, 5゛...9900 through hole, 5'
a=...flange pipe, 5°''...hole, 5゛°a...passage, 6...blind hole, 6'...
...Through hole, 6°a...Flanged pipe, 6°°
... Hole, 6"'a ... Passage, 7...
・Gasket, 8...Semi-permeable membrane, 9...Cell ring, lO...Bolt hole, ll...
Cutting line, 12... Concentrator, 13... Spacer, 21... Raw material aqueous solution storage tank, 22...
・Pump, 23...Filter, 24...
・Head tank, 24a...Heating/cooler, 2
5... Overflow pipe, 26... Flow rate regulator, 27... Product storage tank, 28...
pump, 31...receiving tank, 32...heater, 33...vacuum pump, 34...regenerator, 34a...cooler, 35...Pump, 36...Head tank, 36a...
・Heating/cooling device, 37...Storage tank, 38...
...Flow rate regulator, a, b... Continuous hole, A, B.
...Flow path.

Claims (2)

[Claims] (1) A concentrator having respective channels into which an aqueous solution and a hyperosmotic solution are successively introduced and flow out after coming into contact with each other through a wide-area water-permeable semipermeable membrane, and the aqueous solution is sent to the concentrator. An apparatus for concentrating an aqueous solution, comprising a means for supplying the high osmotic pressure liquid, a means for circulating the outflowing high osmotic pressure liquid to a concentrator, and a regenerator for dehydrating at least a portion of the circulating high osmotic pressure liquid under reduced pressure. (2) The concentrator has a flow path through which the aqueous solution is drawn out in parallel between every other half of the semi-permeable membranes stretched in multiple stages with intervals, and a high permeability channel between every other half of the membranes. 2. The aqueous solution concentrating device according to claim 1, which is a concentrator having a channel through which a pressure liquid flows in parallel and is extracted.