JP2001162105A - Separating device using gravity difference and filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separating device using gravity difference for removing foreign materials of fine particles contained in a liquid mixture consisting of plural liquids different in gravity being the liquid to be filtrated and separating the liquid mixture into each component and to provide a filter using the separating device. SOLUTION: A partition wall 4 is disposed in a housing 1, which is partitioned into an inflow side region R1 and an outflow side region R2 by a filter member 3, to form in the region R1 a region R4 having the inlet 2a of the liquid L to be filtrated and a housing region R3 for housing a floating liquid (oil component O) by gravity difference in order to separate the region R4 from the region R3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a specific gravity separation device for filtering a fluid to be filtered mixed with oil and water, and a filtration device provided with the specific gravity difference separation device, which improves the efficiency of removing an oil component from the fluid to be filtered. Related to technology.

[0002]

2. Description of the Related Art Conventionally, microfiltration membranes and ultrafiltration membranes have been used in filtration devices that have been used for reusing a washing liquid or the like (water-soluble) for cleaning a work to which an oil component has adhered and for performing wastewater treatment. Some use.

[0003] In this method, a cleaning liquid containing an oil component to be a liquid to be filtered is passed through a membrane having micropores much smaller than the size of oil droplets contained therein, and the cleaning liquid is filtered.
An oil component and a cleaning liquid component are separated to obtain a cleaning liquid containing no oil component (very low concentration).

In a filtration apparatus 100 illustrated in FIG. 7, a hollow fiber membrane module 103 using a bundle of a large number of hollow fiber membranes 102 as an ultrafiltration membrane as a membrane-based filtration means in a circulation path 101 is provided. Have.

The cleaning liquid (for example, containing 50 to 200 ppm of oil component) supplied from the supply path 110 is supplied to the pump 1
At 04, the flow is made to flow parallel to the inner surface of the membrane wall of the hollow fiber membrane 102 (this circulation path 101 is also called a cross flow path), and a part of the washing liquid at that time is filtered through the membrane wall. , Permeate (0 to 1 ppm)
(A cleaning liquid containing an oil component).

On the other hand, the unfiltered cleaning liquid is recirculated through the circulation path 101 to be concentrated, and the concentrated liquid is supplied to the discharge path 112 from the concentrated liquid having a higher oil content (for example, 300 pp).
m oil component). In this way, the oil component and the cleaning liquid are separated to obtain a cleaning liquid containing no oil component.

[0007] In such a filtering apparatus 100, the supplied cleaning liquid may contain foreign matter (particulates) in some cases, and removing the foreign substance is necessary to prevent the hollow fiber membrane module 103 from being clogged or damaged. Important, supply route 1
The filter means 105 is provided in the circulation path 101 and the circulation path 101 (disposed in the circulation path 101 in FIG. 7).

FIG. 8 is a diagram showing a conventional example of the structure of the filter means 105. FIG. 8A shows a bag filter (filter means 105A), and FIG. 8B shows a cartridge filter (filter means 105B). ).

The filter means 105A shown in FIG. 8A is provided with an inlet 122 provided at the upper part of the filter housing 121.
The cleaning liquid to be filtered flows from the filter member 123, passes through a filter member 123 (bag filter) formed of a porous body, a nonwoven fabric, or the like, and is provided at a lower portion of the filter housing 121 in a state where foreign substances and the like are removed by the filter member 123. Out of the outlet 124.

The filter means 105B shown in FIG. 8 (b) has a cylindrical filter member 128 (cartridge filter) made of a porous material or non-woven fabric, into which a cleaning liquid to be filtered flows through an inlet 127 of the filter housing 126.
From the outer peripheral surface side to the inner peripheral surface side, and flows out from the outlet 129 in a state where foreign substances and the like are removed by the filter member 128.

However, the filtering device 1 having the above-described configuration
In the case of 00, the washing liquid to be filtered (concentrated washing liquid)
If the concentration of the oil component in the hollow fiber membrane is high,
The oil film adheres to the membrane surface of No. 2 and forms an oil film without leaving, and the pores of the membrane are closed, thereby reducing the filtration ability. If the oil component concentration is equal to or higher than a predetermined range, it becomes difficult to improve the oil-water separation efficiency.

For this reason, the oil component in the cleaning liquid is removed in advance on the upstream side of the circulation path 101 or on a path separate from the circulation path 101 to control the concentration of the oil component in the circulation path 101 within a predetermined range. It is necessary to limit the flow rate of the cleaning liquid supplied to the circulation path 101.

In order to separate oil components in the washing liquid, there is a floating oil collecting means 130 (specific gravity difference separating apparatus) shown in FIG.

That is, the floating oil collecting means 130 includes a retaining tank 131, in which the cleaning liquid to be filtered is supplied and retained in the retaining tank 131, and the oil component O is converted into the water component W ( The floating oil (oil component O) is discharged from the oil component discharge path 132.

The storage tank 131 shown in FIG. 9 is further provided with a filter member 133 such as a coalescer filter to promote separation due to a difference in specific gravity. That is, when the cleaning liquid passes through the filter member 133, the oil droplets tend to aggregate and float easily, and the oil component and the water component are separated more efficiently.

The cleaning liquid having a reduced concentration of the oil component passes through the filter member 133 and passes from the filtrate path 134 to the circulation path 1.
01 is supplied.

FIGS. 10 and 11 are diagrams schematically showing the circuit configurations of filtration devices 150 and 160 provided with the filter means 105 and the floating oil recovery means 130 in the prior art.

In the filtration device 150, the hollow fiber membrane module 1
The configuration includes a circulation path 151 serving as a cross flow path 03 and a filtration circulation path 152 in which the filter means 105 and the floating oil recovery means 130 are arranged in series upstream of the circulation path 151.

In the filtration device 160, the hollow fiber membrane module 1
And a circulation path 162 for connecting the filter means 105 and the floating oil recovery means 130 in parallel before and after the hollow fiber membrane module 103 of the circulation path 161, respectively. is there.

As described above, the foreign matter and the oil component of the cleaning liquid to be filtered are removed by the filtering devices 150 and 160 as shown in FIGS.

Although not shown in the drawing, a circulation path 15 serving as a cross flow path is not shown in the actual filtration device.
1, 161 and the circulation paths 152, 162, 163 in which the filter means 105 and the floating oil recovery means 130 are arranged.
Since the flow rates are different from each other, the flow rate is adjusted by appropriately providing a flow control valve or the like in the middle of each circulation path or at a branch portion.

A more detailed configuration is described in Japanese Utility Model Laid-Open No. Hei 7-31129 and Japanese Patent Laid-Open No. Hei 9-215901 by the same applicant and can be referred to.

[0023]

As described above, in the filtration device, it is necessary to remove the foreign matter and the oil component of the cleaning liquid to be filtered. Therefore, both the filter means 105 and the floating oil recovery means 130 are usually provided. Will be done.

However, the conventional filter means 105
The floating oil collecting means 130 has the following problem.

The oil component cannot be removed only by the filter means 105.

The floating oil collecting means 130 requires a large storage space because a retaining tank 131 for floating the oil component due to a difference in specific gravity is required.

The direct arrangement of the floating oil recovery means 130 on the circulation paths 151 and 161 which are cross-flow paths is because the circulation flow rate of the cleaning liquid is large in the circulation paths 151 and 161 (cross-flow path). It is difficult for the cleaning liquid to stay for the time required for floating
As shown in FIG. 11 and FIG. 11, a circulation path different from the cross flow path must be provided and arranged. Therefore, circulation route 1
It was not possible to filter the entire amount of the washing liquid in the flow passages 51 and 161 (cross flow path), and a piping and a flow control valve were required, which led to a complicated apparatus configuration.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to remove particulate foreign matter contained in a mixture of a plurality of liquids having different specific gravities which are liquids to be filtered. Another object of the present invention is to provide a specific gravity difference separation device that enables liquid separation of a mixed liquid, and a filtration device using the specific gravity difference separation device.

[0029]

In order to achieve the above object, in a specific gravity difference separation apparatus according to the present invention, a container into which a mixture of a plurality of liquids having different specific gravities as a liquid to be filtered flows in through an inlet. A filter member that divides the inside of the container into an inflow-side area and an outflow-side area of the liquid to be filtered; and a liquid that floats due to a difference in specific gravity from a region having an inlet of the liquid to be filtered in the inflow-side area. And a partition formed to be separated from a region to be formed.

With this configuration, foreign substances (fine particles) in the liquid to be filtered can be removed by the filter member. In addition, the liquid that floated due to the difference in specific gravity in the inflow-side region of the container is separated from the region into which the liquid to be filtered flows by the partition wall so that the liquid is hardly agitated without being affected by the flow of the liquid to be filtered. As a result, the liquid mixture can be kept in an area for accommodating the floating liquid (referred to as an accommodating area), and the mixed liquid can be separated.

When the partition wall is substantially upright and the inflow-side region of the container of the specific gravity difference separation device is divided in the horizontal direction, the liquid that floats due to the specific gravity difference is directly guided to the storage region and enters the storage region. stay.

When the partition wall is substantially horizontal or slightly inclined, an inflow port is disposed below the partition wall, so that the upper side of the inflow side area of the container of the specific gravity difference separator is divided as a storage area, and the specific gravity difference is obtained. The liquid that floats is guided to the storage area and stays in the storage area. When the partition wall is inclined, the liquid that floats due to the specific gravity difference along the inclination can be moved and collected.

It is also preferable that the partition has a cylindrical shape, and a region for containing a liquid floating due to a specific gravity difference from a region having an inlet for the liquid to be filtered is separated inside and outside the partition.

With this configuration, it is possible to further suppress the influence of the flow of the liquid to be filtered, which flows into the region into which the liquid to be filtered flows.

Preferably, the filter member has an upright cylindrical portion located outside the partition.

When the liquid to be filtered passes through the cylindrical portion of the filter member which is substantially vertical, liquid droplets floating due to a difference in specific gravity can be temporarily held on the surface of the filter member to grow. Efficiency is improved.

By locating the area for containing the liquid that floats on the outside of the cylindrical partition wall, the liquid droplets grown on the surface of the upright cylindrical portion of the filter member can be more reliably transferred to the area for containing the liquid that floats. Can be led.

[0038] It is also preferable to provide a discharging means for discharging the liquid collected in the area for storing the liquid floating on the upper part of the container due to the difference in specific gravity.

As the discharging means, for example, there is a discharging path connected to the upper part of the container, and a valve is provided, and it is possible to discharge the liquid that floats as needed or periodically due to a difference in specific gravity.

[0040] In a filtration apparatus for performing filtration for circulating a liquid to be filtered through a circulation path provided with a membrane-based filtration means to produce a membrane permeate, the above-described specific gravity difference separation apparatus is connected to the circulation path. It is characterized by the following.

In this filtering device, the removal of foreign matter and the removal of the liquid floating due to the specific gravity difference in the liquid to be filtered can be performed simultaneously by the specific gravity difference separating device.

The specific gravity difference separator can be connected in series to the circulation path to perform the total filtration of the liquid to be filtered flowing in the circulation path.

It is also possible to branch off from the circulation path and connect them in parallel, so that the concentration of the liquid to be filtered in the circulation path can be adjusted according to the amount of inflow into the specific gravity difference separation device. .

[0044]

(Embodiment 1) A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional configuration diagram of the specific gravity difference separation device 1.

The schematic configuration of the specific gravity difference separating apparatus 1 is a bottomed cylindrical housing as a container into which a mixed liquid of a plurality of liquids having different specific gravities (for example, a cleaning liquid containing an oil component) flows as the liquid L to be filtered. 2, a filter member 3
And the partition 4 are arranged, and the upper opening is sealed by the lid member 5.

An inlet 2a through which the liquid L to be filtered flows is provided on the upper side wall surface of the housing 2.
Is provided with an outlet 2b at the bottom.

A dome-shaped (upside down) filter member 3 is provided below the inlet 2a with an opening (lower part of the dome).
Are arranged on the upper side. This filter member 3
The inside of the housing 2 is divided into an inflow side region R1 and an outflow side region R2 of the liquid L to be filtered.

The material, the opening diameter and the like of the filter member 3 can be appropriately selected in consideration of the material and size of the fine particles contained in the liquid L to be filtered, the filtration resistance and the like. For example, a ceramic or non-woven fabric is hardened so as not to damage the opening.

The filter member 3 includes an upright cylindrical portion 3a, an end surface portion 3b for closing the bottom of the cylindrical portion 3a, and an upper housing 2
And a fixing portion 3c fixed to the inside of the device.

The partition 4 has a cylindrical shape with a cylindrical shape. The upper part is fixed to the lid member 5 and the lower part is open. The inside of the partition 4 is an inflow side region R of the liquid L to be filtered.
In FIG. 1, a storage area R3 for storing liquid floating due to a difference in specific gravity is provided, and a discharge path 6 serving as discharge means connected to the storage area R3 and a valve 7 for controlling discharge of liquid discharged from the discharge path 6 are provided on the lid member 5. Is provided. The outside of the partition 4 is a region R4 having an inflow port.

The partition wall 4 extends to substantially the center of the housing 2 where the flow of the liquid L to be filtered in the inflow-side region R1 is stable.

In the specific gravity difference separating apparatus 1 configured as described above, when the liquid L to be filtered flows into the inflow side region R1 inside the housing 2 from the inflow port 2a, the liquid L is entirely in the upper part as indicated by the flow path indicated by the arrow. From the outlet to the lower part, and flows out from the outlet 2b as a permeate.

More specifically, the cylindrical portion 3 of the filter member 3
The filter member 3 is transmitted from the inflow side region R1 to the outflow side region R2 outward from the inflow side region R1 while moving down the annular portion between the a and the partition 4. At the center of the housing 2, the light passes through the end face 3b of the filter member 3 downward.

As the liquid L to be filtered permeates through the filter member 3, the liquid L to be filtered is filtered by the filter member 3.
Foreign matter (fine particles) in the inside can be removed.

The liquid (oil component O) floating due to the specific gravity difference in the inflow-side region R1 of the housing 2 is transferred to the partition 4
Thus, the liquid L to be filtered is stored in the storage area R3 separated from the inflow-side area R1 into which the liquid L flows.

The liquid L to be filtered accommodated in the accommodation region R3 is hardly agitated without being affected by the flow of the liquid L to be filtered, and the liquid (oil component O) that floats due to the difference in specific gravity is filtered again. It is possible to stay in the storage region R3 without being dispersed in the target liquid L, and to separate (the oil component O of) the liquid L to be filtered, which is a mixed liquid.

The liquid (oil component O) floating due to the specific gravity difference stored in the storage region R3 opens the valve 7 and
Discharged from

Liquid (oil component O) floating due to difference in specific gravity
Is a droplet that temporarily stays on the surface of the filter member 3 when passing through the cylindrical portion 3a of the filter member 3 that is substantially vertical, and the growth of the droplet is larger in the cylindrical portion 3a than in the horizontal portion. In addition, the separation efficiency of the liquid (oil component O) floating due to the difference in specific gravity is improved.

In this embodiment, the partition wall 4 is substantially upright, and the inflow side region R1 of the housing 2 of the specific gravity difference separator 1 is provided.
Are divided in the horizontal direction, so that the liquid (oil component O) that floats due to the difference in specific gravity is directly guided to the storage region R3 and remains in the storage region R3.

Although not shown, if the partition wall 4 is substantially horizontal or slightly inclined,
a, the housing 2 of the specific gravity difference separation device 1
, The upper side of the inflow side region R1 is partitioned as a storage region R3,
The liquid (oil component O) floating due to the specific gravity difference is stored in the storage region R3.
And stays in the accommodation region R3.

When the partition wall 4 is inclined, the liquid (oil component O) which floats due to the difference in specific gravity along the inclination can be moved and collected efficiently.

(Embodiment 2) FIG. 2A is a view for explaining a cross-sectional structure of a specific gravity difference separating apparatus 11 according to a second embodiment. FIG. 2B is a perspective view of the partition wall 4A. In the specific gravity difference separation device 11, the same components as those of the specific gravity difference separation device 1 of the first embodiment are denoted by the same reference numerals, and duplicate description will be omitted.

As a characteristic configuration of the specific gravity difference separation device 11, an inflow port 5a is provided at the center of the lid member 5, and the liquid L to be filtered is supplied from the inflow port 5a to the region R4 having the inflow port inside the partition wall 4. And flows into the inflow-side region R1.

In the inflow-side region R1, the storage region R3 for storing the liquid that floats due to the specific gravity difference is a cylindrical partition wall 4A.
The housing region R3 is connected to a discharge path 6 and a valve 7 for controlling the discharge of the liquid discharged from the discharge path 6.

Here, the partition wall 4A comprises a cylindrical portion 4A1, a holding portion 4A2 extending radially from the cylindrical portion 4A1, and a holding portion 4A.
And an annular member 4A3 fixed to the tip of the second member 2. The annular member 4A3 is carried by the upper surface of the fixing portion 3c, and is positioned and fixed by the upper end of the cylindrical portion 4A1 abutting against the lower surface of the lid member 5. ing.

The specific gravity difference separating apparatus 11 configured as described above
Then, when the liquid L to be filtered flows into the inflow-side region R1 inside the housing 2 from the inflow port 5a, it flows from the upper part to the lower part as a flow path indicated by an arrow, and becomes a permeate, and flows out from the outflow port 2b. I do.

With the permeation of the liquid L to be filtered through the filter member 3, foreign matter (fine particles) in the liquid L to be filtered can be removed by the filter member 3.

The liquid (oil component O) floating due to the specific gravity difference in the inflow side region R1 of the housing 2
The liquid A to be filtered is stored in the storage region R3 separated from the inflow-side region R1 into which the filtration target liquid L flows.

The liquid L to be filtered accommodated in the accommodation region R3 is hardly agitated without being affected by the flow of the liquid L to be filtered, and the liquid (oil component O) that floats due to the difference in specific gravity is filtered again. It is possible to stay in the storage region R3 without being dispersed in the target liquid L, and to separate (the oil component O of) the liquid L to be filtered, which is a mixed liquid.

The liquid (oil component O) floated due to the specific gravity difference stored in the storage region R3 opens the valve 7 and
Discharged from

Liquid (oil component O) that floats due to the difference in specific gravity
Is a droplet that temporarily stays on the surface of the filter member 3 when passing through the cylindrical portion 3a of the filter member 3 that is substantially vertical, and the growth of the droplet is larger in the cylindrical portion 3a than in the horizontal portion. In addition, the separation efficiency of the liquid (oil component O) floating due to the difference in specific gravity is improved.

In this embodiment, in particular, the storage region R3 for storing the floating liquid (oil component O) is located at a position where the droplet grown on the surface of the cylindrical portion 3a floats along the cylindrical portion 3a. Thus, the liquid (oil component O) that floats more reliably can be guided to the storage region R3.

(Confirmation Experiment) The effect of providing the partition walls 4 was confirmed by an experimental apparatus 21 (specific gravity difference separation apparatus) as shown in FIG. The housing 2 is a closed cylindrical container having a diameter D1 of 70 mm and a height H1 of 130 mm. A cylindrical partition wall 4 having a diameter D2 of 40 mm and a height H2 of 30 mm is detachably provided at an upper portion.

The center position of the inflow port 2a of the liquid L to be filtered is a position 18 mm lower than the upper part of the housing 2,
The center position of the outlet 2b is 10m from the lower part of the housing 2.
m is the position where it has risen. No filter member was provided in the housing 2.

The experiment was performed for each of the state in which the partition walls 4 were provided and the state in which the partition walls 4 were not provided, and the amount of floating liquid (oil component O) recovered was compared.

A liquid L to be filtered containing a dispersed oil having an oil component concentration of 1% flows into the housing 2 from the inlet 2a at a flow rate of 1.8 (l / min) for 10 minutes, and is discharged from the outlet 2b. Was.

FIG. 4 is a table showing the results of comparison of the amount of recovered liquid (oil component O) separated in the housing 2. 37.6 (g) is provided with the partition 4 and the partition 4
The sample not provided with was 3.8 (g). Under these conditions, by providing the partition walls 4, the recovery amount can be increased by about 10 times, and the effect was confirmed.

(Embodiment 3) FIG. 5 shows a circulation path 51 provided with a hollow fiber membrane module 52 as a membrane-based filtration means.
The liquid L to be filtered is circulated through the hollow fiber membrane module 5
It is a schematic diagram of the filtration device 50 which performs filtration which produces | generates a membrane permeate from 2 permeate path | routes 52a.

In the circulation path 51, a pump 53 for circulating the liquid L to be filtered and a specific gravity difference separator 1 similar to that described in the first embodiment are arranged in series.

In this filtration device 50, a membrane permeated liquid in which the oil component is almost completely separated (extremely low concentration) is obtained by the hollow fiber membrane module 52, and the particulate matter foreign matter is removed by the specific gravity difference separation device 1. And the liquid floating due to the specific gravity difference in the liquid L to be filtered can be removed at the same time.

When the hollow fiber membrane module 52 is used in a cross flow system, a large amount (for example, 1
00 (l / min)), it is necessary to flow the liquid L to be filtered, and the specific gravity difference separator 1 can pass the entire amount of the liquid L to be filtered as in this embodiment, and the hollow fiber membrane is clogged. High prevention effect.

In the conventional floating oil collecting means having a stagnation tank having the same volume as the specific gravity difference separating apparatus 1, the flow rate is limited to a small amount (for example, 10 (l / min)).

Therefore, unlike the prior art, the filter means and the floating oil collecting means are not separately provided, but a large stagnation tank which is required in the conventional floating oil collecting means is not required, so that it is simple and compact with a small installation space. Configuration.

Further, since it can be directly disposed in the cross flow type circulation path 51, the flow path configuration is not complicated.

In this embodiment, a cross-flow type filtration device is provided with a specific gravity difference separation device. However, it is needless to say that the present invention can be applied to filtration devices other than the cross-flow type filtration device. .

(Embodiment 4) FIG. 6 shows a circulation path 51 having a hollow fiber membrane module 52 as a membrane-based filtration means.
The liquid L to be filtered is circulated through the hollow fiber membrane module 5
It is a schematic diagram of the filtration device 60 which performs filtration which produces | generates a membrane permeate from the 2 permeate path | route 52a.

In this embodiment, a specific gravity difference separator 1 similar to that described in the first embodiment is provided in the circulation path 51 in parallel with the hollow fiber membrane module 52.
The path 61 provided with the hollow fiber membrane module 52 connects from the upstream branch part S1 of the hollow fiber membrane module 52 to the downstream junction S2.

When adjusting the inflow amount of the liquid L to be filtered from the branch portion S1, a flow control valve (not shown) may be provided between the branch portion S1 and the specific gravity difference separating device 1. .

In such a configuration, as in the third embodiment, in the filtration device 50, the hollow fiber membrane module 5 is used.
2 obtains a membrane-permeated liquid in which the oil component is almost completely separated (very low concentration), and the specific gravity difference separation device 1 removes particulate foreign matter and floats due to the specific gravity difference in the liquid L to be filtered. Can be removed simultaneously.

By providing the specific gravity difference separator 1 in parallel with the circulation path 51, the amount of the liquid L to be filtered into the specific gravity difference separator 1 can be adjusted.

This configuration is suitable when the flow rate of the specific gravity difference separation device 1 is set smaller than the flow rate of the hollow fiber membrane module 52. The capacity (difference in flow rate) can be balanced.

Alternatively, when the processing capacity of the specific gravity difference separation device 1 is high, the concentration of the liquid to be filtered in the circulation path 51 can be adjusted to an optimum value, and the filtration efficiency can be improved.

Unlike the prior art, the filter means and the floating oil collecting means are not separately provided. Instead, a large holding tank required by the conventional floating oil collecting means is not required, so that a simple and compact installation space is required. Is the same as in the third embodiment.

[0094]

According to the specific gravity difference separation apparatus of the present invention described above, the removal of the particulate foreign matter contained in the liquid mixture to be filtered and the liquid separation of the liquid mixture are simultaneously performed. And a compact configuration with a small installation space can be achieved.

By making the partition wall cylindrical, the influence of the flow of the liquid to be filtered which flows into the region into which the liquid to be filtered flows is suppressed, and the separation efficiency is further improved.

When the liquid to be filtered passes through the cylindrical portion of the filter member, which is substantially vertical, liquid droplets that float due to the difference in specific gravity can be temporarily retained on the surface of the filter member and grown. Efficiency is improved.

Further, by connecting the specific gravity difference separation device to a circulation path having a membrane-based filtration unit, the filtration efficiency of the membrane-based filtration unit can be increased and the life can be extended.

When a specific gravity difference separation device is connected in series to the circulation path, it is possible to perform the total filtration of the liquid to be filtered flowing in the circulation path, and the structure of the flow path is not complicated, and the apparatus is not complicated. However, the configuration becomes simple and the reliability is improved.

When the specific gravity difference separator is connected in parallel by branching from the circulation path, it is possible to adjust the concentration of the liquid to be filtered in the circulation path according to the amount of inflow into the specific gravity difference separation apparatus. In addition, the filtration efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a specific gravity difference separation device according to a first embodiment.

FIG. 2 is a diagram of a specific gravity difference separation device according to a second embodiment.

FIG. 3 is a diagram of an experimental apparatus.

FIG. 4 is a table showing a comparison result of a recovery amount of a floating liquid (oil component O).

FIG. 5 is a diagram of a filtration device provided with a membrane-based filtration unit.

FIG. 6 is a diagram of a filtration device provided with a membrane-based filtration unit.

FIG. 7 is a diagram of a conventional filtration device.

FIG. 8 is a diagram showing a configuration of a conventional filter means.

FIG. 9 is a view showing a conventional floating oil collecting means.

FIG. 10 shows a conventional filtration device provided with a filter means and a floating oil recovery means.

FIG. 11 shows a conventional filtration device provided with a filter means and a floating oil recovery means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Specific gravity difference separation apparatus 2 Housing 2a Inflow port 2b Outflow port 3 Filter member 3a Cylindrical part 3b End part 3c Fixed part 4, 4A Partition wall 5 Cover member 6 Discharge path 7 Valve 50 Filtration device 51 Circulation path 52 Hollow fiber membrane module 53 Pump L Liquid to be filtered R1 Inflow area R2 Outflow area R3 Storage area R4 Area with inlet

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[Procedure amendment]

[Submission date] December 14, 1999 (1999.12.
14)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG. 8

FIG. 9

FIG. 10

FIG. 11

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA02 HA02 HA18 JA51A JA59A KA02 KA16 KA41 KA63 KB30 MA01 PA01 PB14 PC23 4D051 AA01 BA03 BA07 BA08 BA09

Claims (5)

[Claims] 1. A container into which a mixed liquid of a plurality of liquids having different specific gravities is introduced from an inlet as a liquid to be filtered, and a filter for dividing the inside of the container into an inflow-side area and an outflow-side area of the liquid to be filtered. A specific gravity difference separation device, comprising: a member; and a partition formed in the inflow-side region so as to separate a region having an inflow port of the liquid to be filtered and a region containing a liquid floating due to a specific gravity difference. 2. The partition according to claim 1, wherein the partition has a cylindrical shape, and separates an area for containing a liquid floating due to a difference in specific gravity from an area having an inlet for a liquid to be filtered, inside and outside the partition. The specific gravity difference separation device according to 1. 3. The specific gravity difference separating apparatus according to claim 2, wherein the filter member includes an upright cylindrical portion located outside the partition. 4. The apparatus according to claim 1, further comprising a discharge unit configured to discharge liquid collected in an area for storing liquid floating due to a difference in specific gravity at an upper portion of the container.
The specific gravity difference separation device according to item. 5. A filtration device for performing filtration for producing a membrane permeated liquid by circulating a liquid to be filtered through a circulation path having a membrane-based filtration means, according to any one of claims 1 to 4. A filtering device, wherein a specific gravity difference separating device is connected to the circulation path.