JPH0252978B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a flat membrane tester for testing the permeation performance of solutions or slurry liquids that cause gel polarization in reverse osmosis membranes and ultrafiltration liquid separation membranes. be.

Conventionally, the methods of this type of tester have been broadly classified into batch type and continuous type. The batch type, for example, uses a stirring blade 2 that rotates near the sample film 1 as shown in Fig. 1.
The stock solution 4 is placed in a cylindrical tank 3 equipped with a cylindrical tank 3, and nitrogen gas is injected from the inlet 5 to pressurize it for testing. This device does not have a continuous supply operation, and the overspeed of the solution or slurry changes depending on the degree of stirring, such as the shape, position, and rotation speed of the stirring blade, so it is not only difficult to obtain stable data, but also continuous feeding. The method differs from the actual treatment equipment that requires operation in that the method for supplying the stock solution is different, and the test solution has the disadvantage that the concentration of the sample solution changes as the test time passes.

On the other hand, in a conventional continuous flat membrane tester, for example, the device shown in FIG. 2, the sample membrane 6 is sandwiched between two plates 7 and 8 via an O-ring, and the stock solution enters through the inlet 11 and flows out through the outlet 12. Although this problem can be avoided, both have problems with flow path settings. In other words, since the membrane surface is usually sealed only with an O-ring, the height of the flow path is regulated by adjusting the tightening. The height changes, and as a result, in a solution system that forms a gel layer, water permeability is greatly affected. Furthermore, in this case, although the flow lines of the stock solution are shown by arrows in Figure 3, it is difficult to set the flow path length of the stock solution to be the same for all liquid flows, and the flow in the actual processing equipment is different from the flow line of the stock solution. There is a concern that the characteristics of each point of the film may be different, and the reliability of the measured values may be low, or the measurements must be taken with great care, which is troublesome.

The present inventors have arrived at the present invention as a result of various studies. In other words, each has a distribution mechanism for the undiluted solution and the filtrate,
In a separation membrane tester in which a separation membrane can be held between two plates that can be brought into contact and tightened, the first plate has a rectangular recess as a flow path and two opposite sides of the rectangular recess. A pair of distribution grooves each having a substantially constant depth that is twice the depth and having a hole in the center that communicates with the opposite side of the board, and an O-ring groove that surrounds the recess and the groove without contacting them. The second plate has a pair of holes that exactly oppose the distribution groove of the first plate and communicate with the opposite side of the plate when the second plate contacts the first plate. It has an O-ring that is fitted into an O-ring groove provided outside the distribution groove and the O-ring groove of the first plate, and is designed to hold a sample film larger than the outer O-ring. Characteristic flat membrane tester.

With this structure, the depth and length of the flow path for the stock solution are approximately regulated by the rectangular recess in the first plate and the deep distribution grooves provided on its two opposing sides.
Since the sample membrane, which is larger than the outer O-ring, is clamped, the clamping area is large and the sample membrane is hardly crushed, and the separation membrane does not protrude into the rectangular recess, so there is a concern that the depth of the original flow channel will be shallow. Less is. Precisely, by setting the clamping area to about 30 cm ² or more, the sample film will not be crushed and variations between the sample film and the test device will be reduced.

In addition, when testing sample membranes of approximately the same thickness and size, it is possible to install a spacer with approximately the same thickness as the sample membrane at a location other than the holding part of the membrane between the two plates. Therefore, the depth of the channel does not vary depending on the tightening strength of both plates.

In this case, there is almost no gap between the sample film and the first disk on the outside of the rectangular portion between the distribution grooves and inside the inner O-ring. Even if the sample film is slightly thin, the liquid flow is stopped by the O-ring, so the gap becomes a dead space and does not affect the measurement results. In the case of a thinner sample membrane, a cloth, porous film, etc. may be layered on the sample membrane so that the thickness approximately matches the thickness of the spacer.

As described above, the present invention eliminates the drawbacks of the conventional device and has the following advantages.

(1) The flow velocity on the membrane surface can be regulated to a constant level.

(2) The dead space on the membrane surface can be kept extremely small. (3) The effective membrane area can be precisely regulated. (4) Measured data can be easily applied to actual equipment. (5) Concentration changes due to fluid concentration can be minimized. Therefore, the length of the flow path can be made as short as possible in order to reduce concentration changes due to concentration in the flow path.

The invention will be explained below with reference to illustrated embodiments.

As shown in FIG. 4, the flat membrane tester of the present invention comprises a first plate 13 and a second plate 14 that can be brought into contact and tightened by spacers 28, 28', and both of these plates have contact resistance and pressure resistance. It is made of plastic materials such as stainless steel, titanium alloy, or acrylic resin, and in addition, it is made of elastic bodies such as O-rings and fasteners such as bolts and nuts for fluid sealing, and if necessary, porous metal or other materials. Composed of plastics, ceramics, etc. The first board 13 is the fourth
As shown in Figures a and b, there is a rectangular recess 15 on its inner surface for forming a liquid flow path, and a pair of grooves 16 and 16' on its two opposing sides for uniformly distributing the fluid. It is equipped with an O-ring groove 19, an O-ring 30, and a fastener hole 20 for sealing the stock solution inlet 17 or stock solution outlet 18 penetrating the opposite side of the panel, and the flow of the stock solution, and a rectangular recess 15.
The hollow part 21 sandwiched between the inner O-ring groove 19 and the two plates are brought into close contact with each other, and the abutting part 22 and the upper and lower plates necessary for maintaining the specified flow path height are accurately and quickly positioned. It consists of a recessed part 23 which is formed in the same direction. In addition, the second plate has grooves 24 and 24' for combining the permeated liquid, holes 25 and 25' for leading out the permeated liquid, and O-rings necessary for collecting the permeated liquid reliably, as shown in C in Fig. 4. The groove 26 and the O-ring 31 are brought into close contact with the upper and lower plates to maintain the specified flow path height, and the contact portion 2
Corresponding to 2, a convex portion 27, preferably on the outside of the O-ring groove 26, allows for accurate and quick positioning of the flat surface and fastener hole necessary for supporting the membrane.
9 consists of keeping it lower than the inside. In these figures, the surfaces of the hollow part 21 and the contact part 22 are O.
The actual flow path height he is equal to the depth ha of the rectangular recess 15 and the spacer 2.
It is determined from the height hb of 8,28' and the film thickness hm used in the test. Furthermore, the height hb of the spacers 28, 28' is determined based on the film thickness hm, and it is usually optimal to set the pressing height hc to 5 to 10 .mu. based on the equation hb≈hm-hc.

From the above, the channel height he is calculated using the following formula.

he=ha+hb-hm Furthermore, the shorter the distance L between the distribution grooves, that is, the flow path length, the easier it is to obtain data with less concentration change, and it is usually desirable that L=1 to 5 cm. On the other hand, if the length W of the distribution groove, that is, the flow path width, is made as long as possible within a range that allows uniform distribution of the stock solution, a large amount of liquid can be obtained and measurement can be made easier.

In addition, if spacers 28, 28' are not provided, the O-ring outside 29 should be flush with the inside of the O-ring.
is also on the same plane as the inside. By increasing the area around the periphery to hold the sample membrane in an area of approximately 30 cm ² or more, it is possible to reduce the crushing of the sample membrane without providing a spacer, and it is possible to perform more accurate measurements than with a vertical device. This is suitable for cases where the sample film has large variations in thickness or size, but when measuring samples with approximately constant thickness, a spacer as described above can significantly reduce individual differences between testers. It's convenient to be able to do it.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional explanatory diagram of a conventional batch-type flat membrane tester, Figure 2 is a vertical cross-sectional explanatory diagram of a conventional continuous-type flat membrane tester, and Figure 3 shows the flow of liquid in the apparatus shown in Figure 2. FIG. 4A is a schematic cross-sectional view taken along line A-A in FIGS. B and C to show the assembly of the flat membrane tester of the present invention;
FIG. 4b is a schematic plan view of the first board (upper board in figure a), and FIG. 4c is a schematic plan view of the second board (upper board in figure a). 13 is the first board, 14 is the second board, 15 is a rectangular recess, 16 and 16' are distribution grooves, 17 is the stock solution inlet, 18 is the stock solution outlet, and 19 is the O-ring of the first board. Groove 21 is a rectangular recess 15 and inner O-ring groove 1
9 is a cavity between them, 24 and 24' are grooves for combining the permeated liquid, and 25 and 25' are holes for leading out the permeated liquid.
26 is an O-ring groove in the second disc, and 28 is a spacer.

Claims (1)

[Scope of Claims] 1. In a separation membrane tester in which a separation membrane can be held between two plates, which each have a flow mechanism for the stock solution and the filtrate and can be brought into contact and tightened, the first plate is , a rectangular recess as a flow path, and a hole on two opposite sides thereof having a substantially constant depth of at least twice the depth of the recess, and communicating with the opposite surface of the board in the center of each side. and an O-ring fitted into an O-ring groove that surrounds the recess and the groove without contacting them, and the second disc has a pair of distribution grooves that are connected to the first disc when the second disc comes into contact with the first disc. A pair of distribution grooves having a hole that accurately faces the distribution groove of the first plate and communicates with the opposite side of the plate, and a pair of distribution grooves that are fitted into an O-ring groove provided outside and away from the O-ring groove of the first plate. A flat membrane tester characterized in that it has an O-ring and is adapted to clamp a sample membrane larger than the outer O-ring. 2 The surface of the second disk facing the first disk that holds the sample film, excluding the distribution groove and O-ring groove, is approximately 30 cm ²
The flat membrane tester according to claim 1, which is one of the above flat surfaces. 3. The flat membrane tester according to claims 1 and 2, wherein a spacer approximately corresponding to the thickness of the sample membrane is provided at a portion of the second plate other than the portion that holds the sample membrane.