8. A membrane cassette in which the plurality of membrane modules according to any one of claims 1 to 7 are arrayed in the predetermined arrangement direction, wherein the water collecting cases of the membrane modules adjacent to each other are detachably coupled via the coupling portions, and the water collecting spaces of the membrane modules adjacent to each other communicate with each other via the flow holes. A membrane element is provided between a pair of water collecting cases. Water collecting spaces in which permeate having penetrated through the membrane element is collected are formed in the water collecting cases. The water collecting case of one membrane module and the water collecting case of the other membrane module are coupled via coupling portions. The coupling portions have flow holes. The water collecting space of the water collecting case of the one membrane module and the water collecting space of the water collecting case of the other membrane module communicate with each other via the flow holes of the coupling portions.

Description
MEMBRANE MODULE AND MEMBRANE CASSETTE
Technical Field
The present invention relates to a membrane module
used for solid-liquid separation in, for example, sewage
and wastewater treatment and sludge concentration, and a
membrane cassette including a plurality of the membrane
modules.
Background Art
Conventionally, as shown in FIGS. 4 0 to 42, the
membrane module of this type includes, for example, a
plurality of filtration membranes 11 having an elongated
tubular shape, holding members 12 and 13 for holding both
ends of the filtration membranes 11, and a reinforcing
frame 14 having the holding members 12 and 13 attached
thereto for reinforcement. Inside the holding member 12,
a water collecting space 16 is formed in which permeate
having permeated through the filtration membranes 11 is
collected. In the holding member 12 on one side, a water
collecting nozzle 18 communicating with the water
collecting space 16 is provided. The water collecting
nozzle 18 projects to the outer side of the holding
member 12.
In the reinforcing frame 14, coupling portions 17 for
coupling membrane modules 15 adjacent to each other in
the up-down direction are provided. The coupling portions
17 include projections 17a provided in the upper part of
the reinforcing frame 14 and recesses 17b provided in the
lower part of the reinforcing frame 14.
A membrane cassette 19 is formed by stacking the
plurality of membrane modules 15 in the up-down direction.
The membrane cassette 19 is immersed in a treatment tank
20. The water collecting nozzle 18 of each of the
membrane modules 15 is connected to a suction pipe 21 for
sucking permeate (filtrate). A suction pump 22 is
connected to the downstream side of the suction pipe 21.
Therefore, when the plurality of membrane modules 15
are stacked in an up-down direction A, the upper membrane
module 15 is coupled to the lower membrane module 15 by
fitting the projection 17a of the lower membrane module
15 in the recess 17b of the upper membrane module 15. It
is possible to prevent the upper membrane module 15 from
disengaging from the lower membrane module 15 in a front-
rear direction B or a left-right direction C.
Permeate having permeated from the outer sides to the
inner sides of the filtration membranes 11 is collected
in the water collecting space 16, flows from the water
collecting space 16 to the suction pipe 21 through the
water collecting nozzle 18, and is extracted to the
outside of the treatment tank 20.
The membrane module 15 is described in Japanese
Patent Application Laid-Open No. H02-86818.
Disclosure of the Invention
Problems to be Solved by the Invention
In the conventional system, since the water
collecting nozzle 18 is provided in the membrane module
15 separately from the coupling portions 17, the number
of components disadvantageously increases. Since the
water collecting nozzle 18 projects to the outer side of
the membrane module 15, the membrane module 15 increases
in size and a space necessary for setting the membrane
module 15 increases.
It is an object of the present invention to prevent a
plurality of membrane modules arrayed adjacent to each
other from disengaging from each other, reduce the number
of components of the membrane modules, and reduce the
sizes of the membrane modules.
Means for Solving the Problems
In order to attain the object, a membrane module of a
first invention which is immersed in a liquid to be
treated and performs filtration, the membrane module
includes:
a pair of water collecting cases; and at least one
membrane element provided between the pair of water
collecting cases, wherein
water collecting spaces in which permeate having
permeated through the membrane element is collected are
formed in the water collecting cases,
the water collecting cases can be coupled via
coupling portions to the water collecting cases of
another membrane module adjacent to the membrane module
in a predetermined arrangement direction,
the coupling portions have flow holes, and
the water collecting spaces communicate with the
water collecting spaces of the water collecting cases of
the other membrane module via the flow holes of the
coupling portions.
Consequently, when the plurality of membrane modules
are arrayed in the predetermined arrangement direction,
the membrane modules adjacent to each other are coupled
via the coupling portions. It is possible to prevent the
membrane modules from disengaging from each other in a
direction orthogonal to the predetermined arrangement
direction.
The liquid to be treated in a treatment tank is
collected as permeate in the water collecting spaces of
the water collecting cases after having permeated through
the membrane elements of the membrane modules to be
filtered. The permeate collected in the water collecting
spaces in this way can flow into the water collecting
spaces in the water collecting cases of the other coupled
membrane module through the flow holes of the coupling
portions. Consequently, the water collecting spaces of
the plurality of membrane modules coupled to each other
communicate with each other via the flow holes of the
coupling portions. The permeate can be extracted to the
outside of the treatment tank from the water collecting
spaces of any one specific membrane module (e.g., a
membrane module located at the outermost end).
As described above, the coupling portions have the
function of coupling the membrane modules adjacent to
each other and the function of causing the water
collecting spaces of the membrane modules adjacent to
each other to communicate with each other. Therefore, a
pipe used exclusively for coupling the water collecting
spaces of the membrane modules adjacent to each other is
unnecessary. The number of components of the membrane
module is reduced and the membrane module is reduced in
size.
In a membrane module of a second invention, the
coupling portions have fitting holes or fitting recesses,
and fitting projections that can be detachably fit into
the fitting holes or fitting recesses in the
predetermined arrangement direction.
Consequently, when the plurality of membrane modules
are arrayed in the predetermined arrangement direction,
the fitting projections of one of the membrane modules
adjacent to each other are fit into the fitting holes or
fitting recesses of the other membrane module (different
membrane module). Thus, the membrane modules adjacent to
each other are coupled via the coupling portions. It is
possible to prevent the membrane modules from disengaging
from each other in a direction orthogonal to the
predetermined arrangement direction.
In a membrane module of a third invention, at least
one of the fitting projections and the fitting holes are
displaceable within a predetermined range in a direction
orthogonal to the predetermined arrangement direction
while keeping water tightness with the water collecting
spaces with which the membrane modules communicate.
Consequently, for example, when the fitting
projections of one of the membrane modules adjacent to
each other are fit into the fitting holes of the other
membrane module (different membrane module) to couple the
one membrane module and the other membrane module in the
predetermined arrangement direction, if the positions of
the fitting projections of the one membrane module and
the positions of the fitting holes of the other membrane
module deviate from each other because of a dimension
error during the manufacture of the membrane modules or a
dimension change caused by heat or contained water, the
fitting projections or the fitting holes are displaced
within the predetermined range in the direction
orthogonal to the predetermined arrangement direction
while keeping water tightness. Thus, the deviation of the
positions of the fitting projections and the positions of
the fitting holes is absorbed. It is possible to surely
fit the fitting projections of the one membrane module
into the fitting holes of the other membrane module.
In a membrane module of a fourth invention, the
coupling portions include tubular members having the
fitting holes and holding mechanisms for holding at least
one of the fitting projections and the tubular members to
be displaceable within the predetermined range in the
orthogonal direction.
In a membrane module of a fifth invention, the
holding mechanisms include annular circumferential wall
portions provided in the water collecting cases, annular
inner brim portions projecting from the ends of the
circumferential wall portions to an inner side in a
radial direction, and holding spaces formed between the
water collecting cases and the inner brim portions, the
fitting projections include outer brim portions
projecting to an outer side in the radial direction and
are inserted into the inner sides of the circumferential
wall portions, and the outer brim portions of the fitting
projections are inserted into the holding spaces.
Consequently, the outer brim portions slide in the
radial direction in the holding spaces, whereby the
fitting projections are displaced within the
predetermined range in the direction orthogonal to the
predetermined arrangement direction while keeping water
tightness. Thus, the deviation of the positions of the
fitting projections and the positions of the fitting
holes is absorbed.
In a membrane module of a sixth invention, the
holding mechanisms include tubular circumferential wall
portions provided in the water collecting cases, holding
grooves formed in the circumferential wall portions, and
holding pawls provided in the fitting projections, the
fitting projections are inserted into the inner sides of
the circumferential wall portions, and the holding pawls
project to the outer side in the radial direction of the
fitting projections and are inserted into the holding
grooves.
Consequently, the holding pawls slide in the radial
direction in the holding grooves, whereby the fitting
projections are displaced within the predetermined range
in the direction orthogonal to the predetermined
arrangement direction while keeping water tightness. Thus,
the deviation of the positions of the fitting projections
and the positions of the fitting holes is absorbed.
A membrane module of a seventh invention includes at
least one of projection inclined surfaces which are
formed in the distal end portions of the fitting
projections and narrowed in the radial direction toward
the distal ends and hole inclined surfaces which are
formed in the outer end portions of the fitting holes and
expanded in the radial direction toward the outer ends.
Consequently, when the fitting projections of one of
the membrane modules adjacent to each other are fit into
the fitting holes of the other membrane module (different
membrane module), the fitting projections are guided to
the fitting holes by at least one of the projection
inclined surfaces and the hole inclined surfaces.
Therefore, the fitting projections are smoothly and
surely fit into the fitting holes.
An eighth invention of a membrane cassette in which
the plurality of membrane modules described in any one of
the first to seventh inventions are arrayed in the
predetermined arrangement direction. The water collecting
cases of the membrane modules adjacent to each other are
detachably coupled via the coupling portions, and the
water collecting spaces of the membrane modules adjacent
to each other are coupled via the flow holes.
Advantages of the Invention
As explained above, according to the present
invention, the membrane modules adjacent to each other
are coupled via the coupling portions. It is possible to
prevent the membrane modules from disengaging from each
other in the direction orthogonal to the predetermined
arrangement direction.
The water collecting spaces of the plurality of
membrane modules coupled to each other communicate with
each other via the flow holes of the coupling portions.
Therefore, the permeate can be extracted to the outside
of the treatment tank from the water collecting space of
any one specific membrane module (e.g., the membrane
module located at the outermost end).
In this way, the flow holes are formed in the
coupling portions and the water collecting spaces of the
plurality of membrane modules communicate with each other
via the flow holes of the coupling portions. Therefore,
the number of components of the membrane module is
reduced and the membrane module is reduced in size.
When the positions of the fitting projections of the
one membrane module and the positions of the fitting
holes of the other membrane module deviate from each
other, the fitting projections or the fitting holes are
displaced within the predetermined range in the direction
orthogonal to the predetermined arrangement direction,
whereby the deviation of the positions of the fitting
projections and the positions of the fitting holes is
absorbed. It is possible to surely fit the fitting
projections of the one membrane module into the fitting
holes of the other membrane module.
The fitting projections are guided to the fitting
holes by at least one of the projection inclined surfaces
and the hole inclined surfaces. Therefore, the fitting
projections are smoothly and surely fit into the fitting
holes.
Brief Description of the Drawings
FIG. 1 is a front view of a membrane cassette
according to a first embodiment of the present invention;
FIG. 2 is a perspective view of the membrane cassette
according to the first embodiment;
FIG. 3 is a perspective view of a membrane module
forming the membrane cassette according to the first
embodiment;
FIG. 4 is a longitudinal sectional view of the
membrane module according to the first embodiment;
FIG. 5 is a side view of a membrane element of the
membrane module according to the first embodiment;
FIG. 6 is a longitudinal sectional view of a coupling
portion of the membrane module according to the first
embodiment and shows a state in which a fitting
projection is fit into a fitting hole;
FIG. 7 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
first embodiment and shows a state in which the fitting
projection is pulled out from the fitting hole;
FIG. 8 is a perspective view of a membrane module
according to a second embodiment of the present
invention;
FIG. 9 is a longitudinal sectional view of the
membrane module according to the second embodiment;
FIG. 10 is a longitudinal sectional view of a
coupling portion of the membrane module according to the
second embodiment and shows a state in which a fit-in
member is fit into a fitting hole;
FIG. 11 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
second embodiment and shows a state in which the fit-in
member is disengaged from the fitting hole;
FIG. 12 is a perspective view of a membrane module
according to a third embodiment of the present invention;
FIG. 13 is a longitudinal sectional view of one of
left and right water collecting cases of the membrane
module according to the third embodiment;
FIG. 14 is a longitudinal sectional view of a
coupling portion of the membrane module according to the
third embodiment and shows a state in which a fitting
projection is pulled out from a fitting hole;
FIG. 15 is a perspective view of the coupling portion
of the membrane module according to the third embodiment
and shows a state in which the fitting projection is
pulled out from the fitting hole;
FIG. 16 is an exploded perspective view of the
coupling portion of the membrane module according to the
third embodiment;
FIG. 17 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
third embodiment and shows a state in which the fitting
projection is fit into the fitting hole;
FIG. 18 is a view taken along arrows V-V of FIG. 17;
FIG. 19 is a perspective view of a membrane module
according to a fourth embodiment of the present
invention;
FIG. 20 is a longitudinal sectional view of a
coupling portion of the membrane module according to the
fourth embodiment and shows a state in which a fitting
projection is pulled out from a fitting hole;
FIG. 21 is a perspective view of the coupling portion
of the membrane module according to the fourth embodiment
and shows the state in which the fitting projection is
pulled out from the fitting hole;
FIG. 22 is an exploded perspective view of the
coupling device of the membrane module according to the
fourth embodiment;
FIG. 23 is a view taken along arrows V-V of FIG. 20;
FIG. 24 is a view taken along arrows Vl-Vl of FIG.
23;
FIG. 25 is a view taken along arrows V2-V2 of FIG.
23;
FIG. 26 is a longitudinal sectional view of a
coupling portion of a membrane module according to a
fifth embodiment of the present invention and shows a
state in which a fitting projection is pulled out from a
fitting hole;
FIG. 27 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
fifth embodiment and shows a state in which the fitting
projection is fit into the fitting hole;
FIG. 28 is a view taken along arrows V-V of FIG. 27;
FIG. 29 is a longitudinal sectional view of a
coupling portion of a membrane module according to a
sixth embodiment of the present invention and shows a
state in which a fit-in member is disengaged from a
fitting hole;
FIG. 30 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
sixth embodiment and shows a state in which the fit-in
member is fit into the fitting hole;
FIG. 31 is a view taken along arrows V-V of FIG. 30;
FIG. 32 is a longitudinal sectional view of a
coupling portion of a membrane module according to a
seventh embodiment of the present invention and shows a
state in which a fitting projection is pulled out from a
fitting hole;
FIG. 3 3 is a view taken along arrows V-V of FIG. 32;
FIG. 34 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
seventh embodiment and shows a state in which the fitting
projection is fit into the fitting hole;
FIG. 35 is a longitudinal sectional view of a
coupling portion of a membrane module according to an
eighth embodiment of the present invention and shows a
state in which a fitting projection is pulled out from a
fitting recess;
FIG. 3 6 is a view taken along arrows V-V of FIG. 35;
FIG. 37 is a longitudinal sectional view of the
coupling portion of the membrane module according to the
eighth embodiment and shows a state in which the fitting
projection is fit in the fitting recess;
FIG. 3 8 is a perspective view of a membrane module
according to a ninth embodiment of the present invention;
FIG. 3 9 is a perspective view of a membrane module
according to a tenth embodiment of the present invention;
FIG. 40 is a longitudinal sectional view of a
conventional membrane module;
FIG. 41 is a perspective view of the conventional
membrane module; and
FIG. 42 is a diagram of a membrane cassette formed by-
stacking a plurality of conventional membrane modules.
Best Mode for Carrying Out the Invention
A first embodiment of the present invention is
explained below on the basis of the drawings.
As shown in FIGS. 1 and 2, reference numeral 31
denotes a membrane cassette. The membrane cassettes 31
are set in a treatment tank 32 and immersed in a liquid
to be treated 33. The membrane cassettes 31 each include
a plurality of membrane modules 34 stacked in an up-down
direction A (an example of a predetermined arrangement
direction).
As shown in FIGS. 3 and 4, each of the membrane
modules 34 includes a pair of left and right water
collecting cases 35a and 35b and a plurality of membrane
elements 36 disposed between the water collecting cases
35a and 35b. Each of the water collecting cases 35a and
35b is a square box-like member including an upper plate
3 7 and a lower plate 38, a front plate 3 9 and a rear
plate 40, and an outer plate 41 and an inner plate 42,
and includes a water collecting space 43 inside. Although
the water collecting cases 35a and 35b are formed in a
square box shape, the water collecting cases 35a and 35b
are not limited to this shape. For example, the water
collecting cases 35a and 35b may have, for example, a
semi-columnar shape, a triangular prism shape, or a
polygonal prism shape.
The membrane elements 3 6 are arrayed in parallel at
predetermined intervals. As shown in FIG. 5, each of the
membrane elements 36 includes a filtration plate 46
having a flat square shape that is a membrane supporting
member and filtration membranes 47 formed of flat
membranes attached to the front and rear surfaces of the
filtration plate 46. Permeate flow channels 48 in the
horizontal direction communicating with the water
collecting space 43 are respectively formed on the front
and rear surfaces of the filtration plate 46.
As the membrane supporting member, in addition to a
rigid filtration plate made of resin or the like, a
filtration plate of a flexible material such as non-woven
fabric or a net may be used.
The inner plates 42 of the water collecting cases 35a
and 3 5b are formed of resin which also serves as an
adhesive. As shown in FIG. 4, the left and right side
edges of each of the membrane elements 3 6 pierce through
the inner plates 42 to reach the water collecting spaces
43. Consequently, the membrane elements 36 are water-
tightly bonded to the water collecting cases 35a and 35b
and are supported between the water collecting cases 35a
and 3 5b.
The water collecting cases 3 5a and 3 5b have upper
coupling surfaces 49 in the upper end portions and have
lower coupling surfaces 50 in the lower end portions.
As shown in FIGS. 3 and 6, the water collecting cases
35a and 3 5b of the lower membrane module 34 are
detachably coupled to the water collecting cases 35a and
3 5b of the upper membrane module 34 (an example of an
adjacent different membrane module). A coupling portion
51 includes, as shown in FIG. 7, a cylindrical fitting
projection 52 which is provided on the upper coupling
surface 49 of each of the water collecting cases 35a and
35b and projects upward and a fitting hole 53 which
provided on the lower coupling surface 50.
The fitting projection 52 can be detachably fit into
the fitting hole 53 in the up-down direction A. A conical
projection inclined surface 54 narrowed in the radial
direction toward the distal end (upper end) thereof is
formed at the distal end portion (upper end portion) of
the fitting projection 52.
The fitting hole 53 is formed in a cylindrical
tubular member 5 8 provided on the lower plate 38. The
upper end of the fitting hole 53 is opened to the water
collecting space 43 and the lower end of the fitting hole
53 is opened to the lower coupling surface 50. A conical
hole inclined surface 55 expanded in the radial direction
toward the lower end (an example of the outer end)
thereof is formed in the lower end portion (an example of
the outer end portion) of the fitting hole 53.
A flow hole 56 opened to the upper end of the fitting
projection 52 and the water collecting space 43 is formed
in the fitting projection 52 and the upper plate 37. A
seal member 57 (e.g., an 0 ring) for sealing between the
inner circumferential surface of the fitting hole 53 and
the outer circumferential surface of the fitting
projection 52 is. provided in the outer circumferential
portion of the fitting projection 52.
As shown in FIG. 6, the water collecting space 43 of
the lower membrane module 34 communicates with the water
collecting space 43 of the upper membrane module 34 via
the flow hole 56 of the fitting projection 52. As shown
in FIG. 2, water collecting pipes 59 are provided on the
left and right outer sides of the top membrane module 34.
The fitting projection 52 of the one water collecting
case 3 5a on the left or right of the top membrane module
34 and the one water collecting pipe 59 on the left or
right thereof are connected via a connection pipe 60.
Similarly, the fitting projection 52 of the other water
collecting case 35b on the left or right and the other
water collecting pipe 59 on the left or right are
connected via the connection pipe 60. A permeate
extracting pipe (not shown) is connected to the water
collecting pipes 59. A suction pump (not shown) is
provided in the permeate extracting pipe.
Gravity filtration with a water head pressure in the
treatment tank 32 set as a driving force can also be used
for the extraction of permeate.
An air diffuser 62 for diffusing gas such as air is
provided below the bottom membrane module 34. The bottom
membrane module 34 is supported on an air diffusing case
63 for leading the gas diffused from the air diffuser 62
to the upper membrane modules 34. The fitting holes 53 of
the bottom membrane module 34 are closed.
Operations in the configuration are explained below.
The membrane cassette 31 is formed by stacking the
plurality of membrane modules 34 on the air diffusing
case 63 in the up-down direction A.
When the plurality of membrane modules 34 are stacked
as explained above, the fitting projection 52 of the
lower membrane module 34 is fit into the fitting hole 53
of the upper membrane module 34 from below to join the
upper coupling surface 4 9 of the lower membrane module 34
and the lower coupling surface 5 0 of the upper membrane
module 34. Consequently, as shown in FIG. 6, the lower
membrane module 34 and the upper membrane module 34
adjacent to each other are coupled via the coupling
portions 51. It is possible to prevent the upper membrane
module 3 4 from disengaging from the lower membrane module
34 in a front-back direction B and a left-right direction
C (an example of a direction orthogonal to the
predetermined arrangement direction (the up-down
direction A)).
When the fitting projection 52 of the lower membrane
module 34 is fit into the fitting hole 53 of the upper
membrane module 34 from below, since the projection
inclined surface 54 is guided in contact with the hole
inclined surface 55, the fitting projection 52 is
smoothly and surely fit into the fitting hole 53.
The water collecting spaces 43 of the plurality of
upper and lower membrane modules 34 coupled to each other
communicate with each other via the flow holes 56 of the
coupling portion 51.
As shown in FIG. 2, the fitting projections 52 of the
top membrane module 34 and the water collecting pipes 59
are connected via the connection pipes 60. Thereafter,
the suction pump and the air diffuser 62 are driven, air
is diffused from air diffusing pipes 64, and a filtration
operation starts.
Consequently, the insides of the membrane elements 3 6
are depressurized and sludge or the like in the liquid to
be treated 33 is captured by the filtration membranes 47
of the membrane elements 36. Permeate having permeated
through the filtration membranes 47 and flowed into the
permeate flow channels 48 of the membrane elements 36
flows into the water collecting spaces 43 of the water
collecting cases 35a and 35b from the permeate flow
channels 4 8 as treated water.
The permeate (i.e., the treated water) collected in
the water collecting spaces 43 of the membrane modules 34
flows from the water collecting space 43 of the lower
membrane module 34 to the water collecting space 43 of
the upper membrane module 34 through the flow holes 56 of
the fitting projections 52 of the coupling portions 51.
Finally, the permeate flows from the water collecting
space 43 of the top membrane module 34 (an example of the
specific membrane module) into the water collecting pipes
59 through the connection pipes 60, flows from the water
collecting pipes 59 to the permeate extracting pipe, and
is extracted to the outside of the treatment tank 32.
In this way, the coupling portions 51 have the
function of separably coupling the lower membrane module
34 and the upper membrane module 34 and the function of
causing the water collecting space 43 of the lower
membrane module 34 and the water collecting space 43 of
the upper membrane module 34 to communicate with each
other. Therefore, a pipe or the like used exclusively for
causing the water collecting space 43 of the lower
membrane module 34 and the water collecting space 43 of
the upper membrane module 34 to communicate with each
other is unnecessary. The number of components of the
membrane module 34 is reduced and the membrane module 34
is reduced in size.
Upflow is generated between the membrane elements 36
by air bubbles diffused from the air diffusing pipes 64.
Due to this upflow, it is possible to prevent solids such
as sludge from depositing on the membrane surfaces of the
membrane elements 3 6 and suppress a rise in permeation
resistance.
In this case, the upper coupling surfaces 4 9 of the
lower membrane module 34 and the lower coupling surfaces
50 of the upper membrane module 34 are in contact with
each other. Therefore, it is possible to prevent the air
bubbles from leaking out to the outside from between the
water collecting cases 35a and 35b of the lower membrane
module 34 and the water collecting cases 35a and 35b of
the upper membrane module 34.
When the membrane cassette 31 is formed by vertically
stacking the plurality of membrane modules 34, the water
collecting cases 35a and 35b of the membrane modules 34
form the sidewalls of the membrane cassette 31. Therefore,
it is unnecessary to provide sidewalls separately from
the water collecting cases 35a and 35b.
In maintenance and inspection, the suction pump and
the air diffuser 62 are stopped to stop a filtration
operation and the connection pipes 60 are removed from
the fitting projections 52 of the top membrane module 34.
Thereafter, as shown in FIG. 3, the upper membrane module
34 is lifted from the lower membrane module 34, whereby
the fitting projections 52 of the lower membrane module
34 are pulled downward from the fitting holes 53 of the
upper membrane module 34. Therefore, if is possible to
lift the respective membrane modules 34 having fixed
weight one by one to above the treatment tank 32 and
remove the membrane modules 34. Consequently, lifting
work can be easily performed.
In the maintenance and inspection, the membrane
cassette 31 may be removed to the outside from the
treatment tank 32 and, thereafter, the respective
membrane modules 34 may be lifted one by one.
In the first embodiment, as shown in FIG. 3, one
fitting projection 52 is provided on the upper plate 37
of the one water collecting case 35a and one fitting hole
53 is provided on the lower plate 38. However, a
plurality of fitting projections 52 and a plurality of
fitting holes 53 may be provided. Similarly, in the first
embodiment, one fitting projection 52 is provided on the
upper plate 37 of the other water collecting case 35b and
one fitting hole 53 is provided on the lower plate 38.
However, a plurality of fitting projections 52 and a
plurality of fitting holes 53 may be provided.
A second embodiment of the present invention is
explained on the basis of FIGS. 8 to 11.
Coupling portions 70 include fit-in members 71, upper
fitting holes 72 provided in upper coupling surfaces 49
of water collecting cases 35a and 35b, and lower fitting
holes 73 provided in lower coupling surfaces 50 of the
water collecting cases 35a and 35b.
As shown in FIG. 11, the fit-in member 71 includes a
disc-like plate portion 74, one fitting projection 75
provided on one side of the plate portion 74, and another
fitting projection 76 provided on the other side of the
plate portion 74. A flow hole 86 is formed in the fit-in
member 71. One end of the flow hole 86 is opened to the
distal end (upper end) of the one fitting projection 75.
The other end of the flow hole 86 is opened to the distal
end (lower end) of the other fitting projection 76.
Conical projection inclined surfaces 79 narrowed in
the radial direction toward the distal ends thereof are
respectively formed at the distal end portion of the one
fitting projection 75 and the distal end portion of the
other fitting projection 76.
The upper fitting holes 72 are formed in a
cylindrical upper tubular member 78 provided on upper
plates 37 of the water collecting cases 35a and 35b.
Upper recesses 77 are formed in the upper coupling
surfaces 4 9 of the upper plates 37. The upper ends of the
upper fitting holes 72 are opened to the upper recesses
77 and the lower ends of the upper fitting holes 72 are
opened to water collecting spaces 43. Conical hole
inclined surfaces 84 expanded in the radial direction
toward the upper ends thereof are formed in the upper end
portions of the upper fitting holes 72.
The lower fitting holes 73 are formed in cylindrical
lower tubular members 81 provided in lower plates 3 8 of
the water collecting cases 35a and 35b. Lower recesses 80
are formed in the lower coupling surfaces 50 of the lower
plates 38. The lower ends of the lower fitting holes 73
are opened to the lower recesses 8 0 and the upper ends of
the lower fitting holes 73 are opened to the water
collecting spaces 43. Conical hole inclined surfaces 85
expanded in the radial direction toward the lower ends
thereof are formed in the lower end portions of the lower
fitting holes 73.
The one fitting projection 75 of the fit-in member 71
can be detachably fit into the lower fitting hole 73 in
an up-down direction A. The upper part of the plate
portion 74 can be detachably fit into the lower recess 80
The other fitting projection 76 of the fit-in member 71
can be detachably fit into the upper fitting hole 72 in
the up-down direction A. The lower part of the plate
portion 74 can be detachably fit into the upper recess 77
A seal member 82 (e.g., an 0 ring) for sealing
between the inner circumferential surface of the lower
fitting hole 73 and the outer circumferential surface of
the one fitting projection 75 is provided on the outer
circumferential portion of the one fitting projection 75
of the fit-in member 71. A seal member 83 (e.g., an 0
ring) for sealing between the inner circumferential
surface of the upper fitting hole 72 and the outer
circumferential surface of the other fitting projection
76 is provided on the outer circumferential portion of
the other fitting projection 76.
As shown in FIG. 8, the upper fitting hole 72 of the
water collecting case 35a on the left or right of a top
membrane module 34 and a water collecting pipe 59 on the
left or right are connected via a connection pipe 60.
Similarly, the upper fitting hole 72 of the other water
collecting case 35b on the left or right and the other
water collecting pipe 59 on the left and right are
connected via the connection pipe 60. The lower fitting
holes 73 of the bottom membrane module 34 are closed.
Operations in the configuration are explained below.
A membrane cassette 31 is formed by stacking a
plurality of membrane modules 34 in the up-down direction
A.
When the plurality of membrane modules 34 are stacked
as explained above, the other fitting projection 76 of
the fit-in member 71 is inserted into the upper fitting
hole 72 of the lower membrane module 3 4 and the lower
part of the plate portion 74 of the fit-in member 71 is
fit into the upper recess 77. In this case, the
projection inclined surface 79 of the other fitting
projection 76 is guided in contact with a hole inclined
surface 84 of the upper fitting hole 72. Therefore, the
other fitting projection 76 is smoothly and surely fit
into the upper fitting hole 72.
Thereafter, the upper membrane module 34 is lowered
onto the lower membrane module 34. In this case, the one
fitting projection 75 of the fit-in member 71 is inserted
into the lower fitting hole 73 of the upper membrane
module 34, the upper part of the plate portion 74 of the
fit-in member 71 is fit into the lower recess 80, and the
upper coupling surface 4 9 of the lower membrane module 34
and the lower coupling surface 5 0 of the upper membrane
module 34 are joined. In this case, the projection
inclined surface 79 of the one fitting projection 75 is
guided in contact with the hole inclined surface 85 of
the lower fitting hole 73. Therefore, the one fitting
projection 75 is smoothly and surely fit into the lower
fitting hole 73.
Consequently, as shown in FIG. 10, the lower membrane
module 34 and the upper membrane module 34 adjacent to
each other are coupled via the coupling portion 70. It is
possible to prevent the upper membrane module 34 from
disengaging from the lower membrane module 34 in a front-
back direction B and a left-right direction C (an example
of the direction orthogonal to the predetermined
arrangement direction (up-down direction A)).
The water collecting spaces 43 of the plurality of
upper and lower membrane modules 34 coupled to each other
communicate with each other via the flow holes 86 of the
coupling portions 70.
Permeate (i.e., treated water) collected in the water
collecting spaces 43 of the respective membrane modules
34 flow from the water collecting space 43 of the lower
membrane module 34 to the water collecting space 43 of
the upper membrane module 34 through the flow hole 86 of
the fit-in member 71 of the coupling portion 70. Finally,
the permeate flows into the water collecting pipes 59
from the water collecting space 43 of the top membrane
module 34 (an example of the specific membrane module)
through the connection pipes 60, flows from the water
collecting pipes 59 to the permeate extracting pipe, and
is extracted to the outside of the treatment tank 32.
In this way, the coupling portion 70 has the function
of separably coupling the lower membrane module 34 and
the upper membrane module 34 and the function of causing
the water collecting space 43 of the lower membrane
module 34 and the water collecting space 43 of the upper
membrane module 34 to communicate with each other.
Therefore, a pipe or the like used exclusively for
causing, the water collecting space 43 of the lower
membrane module 34 and the water collecting space 43 of
the upper membrane module 34 to communicate with each
other is unnecessary. The number of components of the
membrane module 34 is reduced and the membrane module 34
is reduced in size.
In the second embodiment, as shown in FIG. 8, one
upper fitting hole 72 is provided in the upper plate 37
of the one water collecting case 35a, one lower fitting
hole 73 is provided in the lower plate 38, and the upper
fitting hole 72 and the lower fitting hole 73 are coupled
by using one fit-in member 71. However, a plurality of
upper fitting holes 72 and a plurality of lower fitting
holes 73 may be provided and coupled by using a plurality
of fit-in members 71. Similarly, in the second embodiment,
one upper fitting hole 72 is provided in the upper plate
37 of the other water collecting case 35b, one lower
fitting hole 73 is provided in the lower plate 38, and
the upper fitting hole 72 and the lower fitting hole 73
are coupled by using one fit-in member 71. However, a
plurality of upper fitting holes 72 and a plurality of
lower fitting holes 73 may be provided and coupled by
using a plurality of fit-in members 71.
A third embodiment of the present invention is
explained on the basis of FIGS. 12 to 18.
As shown in FIGS. 14 to 16, a coupling portion 87
includes a fitting projection 88, a fitting hole 89, a
holding member 92 (an example of a holding mechanism),
and a flow hole 99. The fitting projection 88 is held on
an upper coupling surface 49 of each of water collecting
cases 35a and 35b, projects upward and is slidable
(displaceable) in a front-back direction B and a left-
right direction C (an example of a direction orthogonal
to a predetermined arrangement direction (an up-down
direction A)) with respect to the upper coupling surface
49. The fitting projection 88 includes a cylinder portion
93 and an outer brim portion 94 provided on the lower end
outer circumferential surface of the cylinder portion 93
and projecting to an outer side in the radial direction.
A conical projection inclined surface 105 narrowed in the
radial direction toward the upper end thereof is formed
in the upper end portion of the cylinder portion 93. The
flow hole 99 is formed in the fitting projection 88 and
an upper plate 3 7 and opened to the upper end of the
fitting projection 88 and a water collecting space 43.
The holding member 92 holds the fitting projection 88
to be slidable within a predetermined range in the front-
back and left-right directions B and C. The holding
member 92 includes an annular circumferential wall
portion 96 vertically provided on the upper coupling
surface 49 of each of the water collecting cases 35a and
35b and an annular inner brim portion 97 projecting from
the upper end portion of the circumferential wall portion
96 to an inner side in the radial direction.
The outer brim portion 94 is inserted in a holding
space 10 0 formed between the upper plate 3 7 and the inner
brim portion 97 of each of the water collecting cases 35a
and 3 5b. The outer brim portion 94 is restrained in the
up-down direction A in a state in which the outer brim
portion 94 is pressed at a proper pressure against the
upper coupling surface 49 and the lower surface of the
inner brim portion 97.
The outer diameter of the outer brim portion 94 is
set smaller than the inner diameter of the
circumferential wall portion 96 and larger than the inner
diameter of the inner brim portion 97. The outer diameter
of the cylinder portion 93 of the fitting projection 88
is set smaller than the inner diameter of the inner brim
portion 97.
A range obtained by subtracting the outer diameter of
the outer brim portion 94 of the fitting projection 88
from the inner diameter of the circumferential wall
portion 96 of the holding member 92 is represented as El.
A range obtained by subtracting the outer diameter of the
cylinder portion 93 of the fitting projection 88 from the
inner diameter of the inner brim portion 97 of the
holding member 92 is represented as E2. Displacement
amounts in the front-back and left-right directions B and
C of the fitting projection 88 are regulated to smaller
one (an example of the predetermined range) of the ranges
El and E2.
A seal member 98 (an 0 ring, etc.) for sealing
between the upper coupling surface 4 9 and the lower end
face of the fitting projection 88 is provided on the
upper plate 37 of each of the water collecting cases 35a
and 35b. Water tightness is secured by this seal member
98 when the fitting projection 88 slides in the front-
back and left-right directions B and C with respect to
the upper coupling surface 49. As shown in FIG. 14(b),
the fitting projection 88 is supported by the seal member
98 while having a slight space above the upper coupling
surface 49.
The seal member 98 only has to seal a space between
the upper plate 37 and the fitting projection 88.
Therefore, the seal member 98 may be provided on the
upper surface or the lower surface of the outer brim
portion 94 or the lower surface of the inner brim portion
97.
The fitting hole 89 is formed in a tubular member 101
provided in a lower plate 38 of each of the water
collecting cases 35a and 35b. A recess 102 is formed in a
lower coupling surface 50 of the lower plate 38. The
lower end of the fitting hole 89 is opened to the recess
102 and the upper end of the fitting hole 89 is opened to
the water collecting space 43. A conical hole inclined
surface 106 expanded in the radial direction toward the
lower end thereof (an example of an outer end) is formed
in the lower end portion of the fitting hole 89 (an
example of an outer end portion).
The fitting projection 88 can be detachably fit into
the fitting hole 89 in the up-down direction A. A seal
member 103 (e.g., an 0 ring) for sealing between the
outer circumferential surface of the cylinder portion 93
and the inner circumferential surface of the fitting hole
89 is provided on the fitting projection 88.
As shown in FIG. 12, the fitting projection 88 of the
coupling portion 87 of the one water collecting case 35a
on the left or right of a top membrane module 34 and one
water collecting pipe 59 on the left or right thereof are
connected via a connection pipe 60. Similarly, the
fitting projection 88 of the coupling portion 87 of the
other water collecting case 35b on the left or right
thereof and the other water collecting pipe 59 on the
left or right thereof are connected via the connection
pipe 60. The fitting holes 89 of a bottom membrane module
34 are closed.
Operations in the configuration are explained below.
When the plurality of membrane modules 34 are
vertically stacked, the fitting projection 88 of the
coupling portion 87 of the lower membrane module 34 is
fit into the fitting hole 89 of the upper membrane module
34 from below to join the upper coupling surface 4 9 of
the lower membrane module 34 and the lower coupling
surface 50 of the upper membrane module 34. Consequently,
as shown in FIG. 17, the lower membrane module 34 and the
upper membrane module 34 adjacent to each other are
coupled via the coupling portions 87. It is possible to
prevent the upper membrane module 34 from disengaging
from the lower membrane module 34 in the front-back
direction B and the left-right direction C (an example of
the direction orthogonal to the predetermined arrangement
direction (the up-down direction A)).
In this way, it is possible to easily couple the
plurality of upper and lower membrane modules 34 to form
a membrane cassette 31. The water collecting spaces 43 of
the plurality of upper and lower membrane modules 34
coupled to each other communicate with each other via the
flow holes 99 of the coupling portions 87.
After the plurality of upper and lower membrane
modules 34 are coupled as explained above to form the
membrane cassette 31, a filtration operation is started.
Consequently, permeate (i.e., treated water) collected in
the water collecting spaces 43 of the respective membrane
modules 34 flow from the water collecting space 43 of the
lower membrane module 34 to the water collecting space 43
of the upper membrane module 34 through the flow holes 99
of the coupling portions 87. Finally, the permeate flows
into the water collecting pipes 59 from the water
collecting space 43 of the top membrane module 34 (an
example of the specific membrane module) through the
connection pipes 60, flows from the water collecting
pipes 59 to a permeate extracting pipe, and is extracted
to the outside of a treatment tank 32.
The filtration operation is stopped and the upper
membrane module 34 is lifted from the lower membrane
module 34. Consequently, as shown in FIGS. 12 to 14, the
fitting projections 88 of the coupling portions 87 of the
lower membrane module 34 are pulled downward from the
fitting holes 89 of the upper membrane module 34.
Consequently, it is possible to remove and separate the
upper membrane module 34 from the lower membrane module
34.
In some cases, the dimensions of the membrane module
34 are different between during manufacture and after use,
because of contained water, a temperature change and the
like due to the use in a liquid to be treated 33. An
error may occur between a space Dl (see FIG. 12) between
the fitting projection 88 of the one water collecting
case 35a and the fitting projection 88 of the other water
collecting case 35b and a space D2 (see FIG. 12) between
the fitting hole 89 of the one water collecting case 35a
and the fitting hole 89 of the other water collecting
case 35b.
In such a case, when the membrane module 34 already
used and the membrane module 34 not used are vertically
stacked and coupled via the coupling portions 87, as
indicated by an imaginary line of FIG. 14, the fitting
projection 88 of the lower membrane module 34 slides in
the front-back direction B or the left-right direction C
to be displaced while keeping water tightness with the
upper coupling surface 49. Consequently, the error
between the space Dl between the left and right fitting
projections 8 8 and the space D2 between the left and
right fitting holes 89 is absorbed. It is possible to
surely insert the fitting projections 88 of the lower
membrane module 34 into the fitting holes 89 of the upper
membrane module 34.
In the third embodiment, as shown in FIG. 12, one
fitting projection 88 is provided on the upper plate 37
of the one water collecting case 35a and one fitting hole
89 is provided on the lower plate 38. However, a
plurality of fitting projections 88 and a plurality of
fitting holes 89 may be provided. Similarly, in the third
embodiment, one fitting projection 88 is provided on the
upper plate 37 of the other water collecting case 35b and
one fitting hole 89 is provided on the lower plate 38.
However, a plurality of fitting projections 88 and a
plurality of fitting holes 89 may be provided.
In the third embodiment, the plurality of membrane
modules 34 are coupled via the coupling portions 87.
However, besides the membrane modules 34, the structure
of the coupling portion 87 may be applied to, for example,
the structure of a joint for connecting pipes.
When the membrane modules 34 are stacked and coupled
by using a crane or the like, it is necessary to align
the positions of the fitting projections 88 of the lower
membrane module 34 and the positions of the fitting holes
89 of the upper membrane module 34. In this case, since
the fitting projections 88 can be displaced in the front-
back and left-right directions B and C and the projection
inclined surfaces 105 are guided in contact with the hole
inclined surfaces 106, if the positions of the fitting
projections 88 and the positions of the fitting holes 89
are aligned to some degree, it is possible to couple the
membrane modules 34 and adjust the positions later.
A fourth embodiment of the present invention is
explained on the basis of FIGS. 19 to 25.
As shown in FIGS. 19 to 22, a coupling portion 110
includes a fitting projection 111, a fitting hole 112, a
holding mechanism 116, and a flow hole 117.
The fitting projection 111 is held by an upper
coupling surface 49 of each of water collecting cases 35a
and 35b, projects upward and is slidable (displaceable)
in a front-back direction B and a left-right direction C
(an example of a direction orthogonal to a predetermined
arrangement direction (an up-down direction A)) with
respect to the upper coupling surface 49.
The fitting projection 111 includes a cylinder
portion 123, a brim portion 124 which is provided on the
lower end outer circumferential surface of the cylinder
portion 123 and projects to an outer side in the radial
direction, and holding pawls 125 provided in two places
in the outer circumferential portion of the brim portion
124. A conical projection inclined surface 133 narrowed
in the radial direction toward the upper end thereof is
formed in the upper end portion of the cylinder portion
123. The flow hole 117 is formed in the fitting
projection 111 and an upper plate 37 and opened to the
upper end of the fitting projection 111 and a water
collecting space 43.
The holding mechanism 116 slidably holds the fitting
projection 111 within a predetermined range in the front-
back and left-right directions B and C. The holding
mechanism 116 includes a circumferential wall portion 119,
insertion grooves 12 0, holding grooves 121, and the
holding pawls 125. The circumferential wall portion 119
has a cylindrical shape and is vertically provided on the
upper coupling surface 49 of each of the water collecting
cases 35a and 35b.
The insertion grooves 120 are formed in two places of
the circumferential wall portion 119 in the up-down
direction A (an axis direction) and reach the upper
coupling surface 49 from the upper end of the
circumferential wall portion 119. The holding grooves 121
are formed in the circumferential direction from the
lower end portions of the insertion grooves 120. These
holding grooves 121 face the upper coupling surface 49.
The one end portions of the holding grooves 121
communicate with the lower end portions of the insertion
grooves 12 0.
The lower part of the fitting projection 111 is
inserted into the inner side of the circumferential wall
portion 119. As indicated by a solid line of FIG. 21, the
holding pawls 125 are respectively inserted into the
holding grooves 121 from the insertion grooves 120.
Consequently, the fitting projection 111 is restrained in
the up-down direction A (the axis direction) in a state
in which the fitting projection 111 is pressed at a
proper pressure toward the upper coupling surface 49.
The outer diameter of the brim portion 124 is set
smaller than the inner diameter of the circumferential
wall portion 119. Consequently, the fitting projection
111 is held to be displaceable in the front-back and
left-right directions B and C (the radial direction of
the fitting projection 111) with respect to the upper
coupling surface 49. Displacement amounts in the front-
back and left-right directions B and C of the fitting
projection 111 are regulated to a range (an example of
the predetermined range) obtained by subtracting the
outer diameter of the brim portion 124 from the inner
diameter of the circumferential wall portion 119.
A seal member 126 (an 0 ring, etc.) for sealing
between the upper coupling surface 4 9 and the lower end
surface of the fitting projection 111 is provided on the
upper plate 37 of each of the water collecting cases 35a
and 3 5b. Water tightness is secured by this seal member
126 when the fitting projection 111 slides in the front-
back and left-right directions B and C with respect to
the upper coupling surface 49. As shown in FIG. 20(b),
the fitting projection 111 is supported by the seal
member 126 while having a slight space above the upper
coupling surface 49.
The seal member 126 only has to be capable of sealing
a space between the upper plate 37 and the fitting
projection 111. Therefore, the seal member 126 may be
provided on the lower surface of the fitting projection
111.
The fitting hole 112 is formed in a tubular member
128 provided on a lower plate 38 of each of the water
collecting cases 35a and 35b. A recess 129 is formed in a
lower coupling surface 50 of the lower plate 38. The
lower end of the fitting hole 112 is opened to the recess
129. The upper end of the fitting hole 112 is opened to
the water collecting space 43. A conical hole inclined
surface 134 expanded in the radial direction toward the
lower end thereof (an example of an outer end) is formed
in the lower end portion of the fitting hole 112 (an
example of an outer end portion).
The fitting projection 111 can be detachably fit into
the fitting hole 112 in the up-down direction A (an
example of the predetermined arrangement direction). A
seal member 131 (e.g., an 0 ring) for sealing between the
outer circumferential surface of the cylinder portion 123
and the inner circumferential surface of the fitting hole
112 is provided on the cylinder portion 123 of the
fitting projection 111.
As shown in FIG. 19, the fitting projection 111 of
the one water collecting case 35a on the left or right of
a top membrane module 34 and one water collecting pipe 59
on the left or right thereof are connected via a
connection pipe 60. Similarly, the fitting projection 111
of the other water collecting case 35b on the left or
right thereof and the other water collecting pipe 59 on
the left or right thereof are connected via the
connection pipe 60. The fitting holes 112 of a bottom
membrane module 34 are closed.
Operations in the configuration are explained below.
When a plurality of membrane modules 34 are
vertically stacked, as shown in FIGS. 24 and 25, the
fitting projection 111 of the lower membrane module 34 is
fit in the fitting hole 112 of the upper membrane module
34 from below to join the upper coupling surface 4 9 of
the lower membrane module 34 and the lower coupling
surface 50 of the upper membrane module 34. Consequently,
the lower membrane module 34 and the upper membrane
module 34 adjacent to each other are coupled via the
coupling portions 110. It is possible to prevent the
upper membrane module 34 from disengaging from the lower
membrane module 34 in the front-back direction B and the
left-right direction C (an example of a direction
orthogonal to the predetermined arrangement direction
(the up-down direction A)).
In this way, it is possible to easily couple the
plurality of upper and lower membrane modules 34 to form
a membrane cassette 31. The water collecting spaces 43 of
the plurality of upper and lower membrane modules 34
coupled to each other communicate with each other via the
flow holes 117 of the coupling portion 110.
The plurality of upper and lower membrane modules 34
are coupled as explained above to form the membrane
cassette 31 and a filtration operation is started.
Consequently, permeate (i.e., treated water) collected in
the water collecting spaces 43 of the respective membrane
modules 34 flows from the water collecting space 43 of
the lower membrane module 34 to the water collecting
space 43 of the upper membrane module 34 through the flow
holes 117 of the coupling portions 110. Finally, the
permeate flows into the water collecting pipes 59 from
the water collecting space 43 of the top membrane module
34 (the specific membrane module) through the connection
pipes 60, flows from the water collecting pipes 59 to a
permeate water extracting pipe, and is extracted to the
outside of a treatment tank 32.
The filtration operation is stopped and the upper
membrane module 34 is lifted from the lower membrane
module 34. Consequently, as shown in FIG. 20, the fitting
projections 111 of the lower membrane module 34 are
pulled downward from the fitting holes 112 of the upper
membrane module 34. Consequently, it is possible to
remove and separate the upper membrane module 34 from the
lower membrane module 34.
In some cases, the dimensions of the membrane module
34 are different between during manufacture and after use,
because of contained water, a temperature change and the
like due to the use in a liquid to be treated 33. An
error may occur between a space Dl (see FIG. 19) between
the fitting projection 111 of the one water collecting
case 35a and the fitting projection 111 of the other
water collecting case 35b and a space D2 (see FIG. 19)
between the fitting hole 112 of the one water collecting
case 35a and the fitting hole 112 of the other water
collecting case 35b.
In such a case, when the membrane module 34 already
used and the membrane module 34 not used are vertically
stacked and coupled via the coupling portions 110, as
indicated by an imaginary line of FIG. 20, the fitting
projection 111 of the lower membrane module 34 slides in
the front-back direction B or the left-right direction C
to be displaced while keeping water tightness with the
upper coupling surface 49. The holding pawls 125 move in
the holding grooves 121. Consequently, the error between
the space Dl between the left and right fitting
projections 111 and the space D2 between the left and
right fitting holes 112 is absorbed. It is possible to
surely insert the fitting projections 111 of the lower
membrane module 34 into the fitting holes 112 of the
upper membrane module 34 from below.
In the fourth embodiment, as shown in FIG. 19, one
fitting projection 111 is provided on the upper plate 37
of the one water collecting case 35a and one fitting hole
112 is provided on the lower plate 38. However, a
plurality of fitting projections 111 and a plurality of
fitting holes 112 may be provided. Similarly, in the
fourth embodiment, one fitting projection 111 is provided
on the upper plate 37 of the other water collecting case
35b and one fitting hole 112 is provided on the lower
plate 38. However, a plurality of fitting projections 111
and a plurality of fitting holes 112 may be provided.
In the fourth embodiment, as shown in FIG. 22, the
insertion grooves 120 and the holding grooves 121 are
formed in the two places of the circumferential wall
portion 119. However, the insertion grooves 120 and the
holding grooves 121 may be formed in three or more places
Similarly, in the fourth embodiment, the holding pawls
125 are formed in two places of the fitting projection
111. However, the holding pawls 125 may be formed in
three or more places.
In the fourth embodiment, the plurality of membrane
modules 34 are coupled via the coupling portions 110.
However, besides the membrane modules 34, the structure
of the coupling portion 110 may be applied to, for
example, the structure of a joint for connecting pipes.
When the membrane modules 34 are stacked and coupled
by using a crane or the like, it is necessary to align
the positions of the fitting projections 111 of the lower
membrane module 34 and the positions of the fitting holes
112 of the upper membrane module 34. In this case, since
the fitting projections 111 are displaceable in the
front-back and left-right directions B and C and the
projection inclined surfaces 133 are guided in contact
with the hole inclined surfaces 134, if the positions of
the fitting projections 111 and the positions of the
fitting holes 112 are aligned to some degree, it is
possible to couple the membrane modules 34 and adjust the
positions later.
A fifth embodiment of the present invention is
explained below on the basis of FIGS. 26 to 28.
The fifth embodiment has substantially the same
configuration as the first embodiment. Therefore, the
same members as those in the first embodiment are denoted
by the same reference numerals and signs and a detailed
explanation thereof is omitted.
A coupling portion 141 includes a cylindrical fitting
projection 52 which is provided on an upper plate 3 7 of
each of water collecting cases 35a and 35b and projects
upward from an upper coupling surface 4 9 and a fitting
hole 53 formed in a lower plate 38. The fitting hole 53
is opened to a lower coupling surface 50 and a water
collecting space 43.
The fitting projection 52 can be detachably fit into
the fitting hole 53 in an up-down direction A. A flow
hole 56 opened to the upper end of the fitting projection
52 and the water collecting space 43 is formed in the
fitting projection 52 and the upper plate 37. A seal
member 142 (e.g., an 0 ring) for sealing between the
upper coupling surface 49 of a lower membrane module 34
and the lower coupling surface 5 0 of an upper membrane
module 34 is provided on the upper coupling surface 49 of
each of the water collecting cases 35a and 35b.
The diameter of the fitting hole 53 is set larger
than the outer diameter of the fitting projection 52.
Consequently, the fitting projection 52 is displaceable
within a predetermined range F in a front-back direction
B and a left-right direction C with respect to the
fitting hole 53 in a state in which the fitting
projection 52 is fit into the fitting hole 53. The
predetermined range F is equivalent to a difference
obtained by subtracting the outer diameter of the fitting
projection 52 from the diameter of the fitting hole 53.
With the configuration, the same operations and
advantages as those in the first embodiment are obtained.
As in the third embodiment, an error may occur between a
space Dl between the fitting projection 52 of the one
water collecting case 35a and the fitting projection 52
of the other water collecting case 35b and a space D2
between the fitting hole 53 of the one water collecting
case 35a and the fitting hole 53 of the other water
collecting case 35b.
In such a case, when the plurality of membrane
modules 34 are vertically stacked and coupled via the
coupling portions 141, if the positions of the fitting
projections 52 are deviated with respect to the positions
of the fitting holes 53 within the predetermined range F,
the fitting projections 52 of the lower membrane module
34 can be fit into the fitting holes 53 of the upper
membrane module 34. Consequently, the error between the
space Dl between the left and right fitting projections
52 and the space D2 between the left and right fitting
holes 53 is absorbed. It is possible to surely insert the
fitting projections 52 of the lower membrane module 34
into the fitting holes 53 of the upper membrane module 34
Water tightness is kept by the seal member 142
between the upper coupling surface 49 of the lower
membrane module 34 and the lower coupling surface 50 of
the upper membrane module 34.
A sixth embodiment of the present invention is
explained below on the basis of FIGS. 29 to 31.
The sixth embodiment has substantially the same
configuration as the second embodiment. Therefore, the
same members as those in the second embodiment are
denoted by the same reference numerals and signs and a
detailed explanation thereof is omitted.
A coupling portion 145 includes a fit-in member 71,
an upper fitting hole 72, and a lower fitting hole 73.
The upper fitting hole 72 is opened to an upper recess 77
and a water collecting space 43. The lower fitting hole
73 is opened to a lower recess 8 0 and the water
collecting space 43.
On one side (upper surface) of a plate portion 74 of
the fit-in member 71, a seal member 146 (e.g., an 0 ring)
is provided for sealing between the upper end face (inner
end face) of the lower recess 8 0 of an upper membrane
module 34 and the one side (upper surface) of the plate
portion 74. On the other side (lower surface) of the
plate portion 74 of the fit-in member 71, a seal member
147 (e.g., an 0 ring) is provided for sealing between the
lower end face (inner end face) of the upper recess 77 of
a lower membrane module 34 and the other side (lower
surface) of the plate portion 74.
The diameter of the fitting holes 72 and 73 is set
larger than the outer diameter of fitting projections 75
and 76 of the fit-in member 71. The diameter of the
recesses 77 and 80 is set larger than the outer diameter
of the plate portion 74 of the fit-in member 71.
Consequently, the fit-in member 71 is displaceable within
a predetermined range F in a front-back direction B and a
left-right direction C with respect to the fitting holes
72 and 73 in a state in which the fit-in member 71 is fit
into the fitting holes 72 and 73 . The predetermined range
F is equivalent to smaller one of a difference obtained
by subtracting the outer diameter of the fitting
projections 75 and 76 from the diameter of the fitting
holes 72 and 73 and a difference obtained by subtracting
the outer diameter of the plate portion 74 from the
diameter of the recesses 77 and 80.
With the configuration, the same operations and
advantages as those in the second embodiment are obtained.
An error may occur between a space Dl between the upper
fitting hole 72 of one water collecting case 35a and the
upper fitting hole 72 of the other water collecting case
35b and a space D2 between the lower fitting hole 73 of
the one water collecting case 35a and the lower fitting
hole 73 of the other water collecting case 35b.
In such a case, when the plurality of membrane
modules 34 are vertically stacked and coupled via the
coupling portions 145, if the positions of the upper
fitting holes 72 are deviated with respect to the
positions of the lower fitting holes 73 within the
predetermined range F, the one fitting projection 75 of
the fit-in member 71 can be fit into the lower fitting
hole 73 and the other fitting projection 76 of the fit-in
member 71 can be fit into the upper fitting hole 7.
Consequently, the error between the space Dl between
the upper left and right fitting holes 72 and the space
D2 between the lower left and right fitting holes 73 is
absorbed. It is possible to surely insert the other
fitting projection 76 of the fit-in member 71 into the
upper fitting hole 72 of the lower membrane module 34. it
is possible to surely insert the one fitting projection
75 of the fit-in member 71 into the lower fitting hole 73
of the upper membrane module 34.
Water tightness is kept by the seal member 146
between the upper end face of the lower recess 8 0 of the
upper membrane module 34 and the one side of the plate
portion 74 of the fit-in member 71. Water tightness is
kept by the seal member 147 between the lower end face of
the upper recess 77 of the lower membrane module 34 and
the other side of the plate portion 74 of the fit-in
member 71.
A seventh embodiment of the present invention is
explained below on the basis of FIGS. 32 to 34.
In the third embodiment, the fitting projection 88 is
displaceable and the fitting hole 89 is fixed. However,
in a coupling portion 151 in the seventh embodiment, a
fitting projection 88 is fixed and a fitting hole 89 is
displaceable. The same members as those in the third
embodiment are denoted by the same reference numerals and
signs and a detailed explanation thereof is omitted.
A recess 152 is formed on an upper coupling surface
49 of each of water collecting cases 35a and 35b. The
cylindrical fitting projection 88 is fixed to a lower
bottom surface 153 (inner bottom surface) of the recess
portion 152.
The fitting hole 89 is formed in a tubular member 154
displaceable in a front-back direction B and a left-right
direction C (an example of a direction orthogonal to a
predetermined arrangement direction (up-down direction
A)) with respect to a lower coupling surface 50. The
tubular member 154 includes a cylinder portion 155 and an
outer brim portion 156 formed on the outer
circumferential surface of the cylinder portion 155. The
cylinder portion 155 is inserted into a through hole 161
formed in a lower plate 3 8 of each of the water
collecting cases 35a and 35b. The lower end of the
fitting hole 89 is opened to the lower end of the
cylinder portion 155. The upper end of the fitting hole
89 is opened to a water collecting space 43.
The tubular member 154 is held on the lower plate 38
of each of the water collecting cases 35a and 35b by a
holding member 157. Like the holding member 92 of the
third embodiment, the holding member 157 includes a
circumferential wall portion 158 and an inner brim
portion 159. The outer brim portion 156 is inserted into
a holding space 160 formed between the lower plate 3 8 of
each of the water collecting cases 35a and 35b and the
inner brim portion 159 of the holding member 157.
A range obtained by subtracting the outer diameter of
the outer brim portion 156 of the tubular member 154 from
the inner diameter of the circumferential wall portion
158 of the holding member 157 is represented as El and a
range obtained by subtracting the outer diameter of the
cylinder portion 155 from the diameter of the through
hole 161 is represented as E2. Displacement amounts in
the front-back and left-right directions B and C of the
fitting hole 89 (i.e., the tubular member 154) are
regulated to smaller one (an example of a predetermined
range) of the range El and the range E2. A seal member
162 (e.g., an 0 ring) for sealing between the lower
coupling surface 50 and the outer brim portion 156 of the
tubular member 154 is provided on the lower plate 3 8 of
each of the water collecting cases 35a and 35b. The outer
brim portion 156 is supported by the holding member 157
in a state in which the outer brim portion 156 is
separated slightly downward from the lower coupling
surface 50.
With the configuration, the same operations and
advantages as those in the third embodiment are obtained.
Specifically, when a plurality of membrane modules 34 are
vertically stacked, the fitting projection 88 of the
coupling portion 151 of the lower membrane module 34 is
fit into the fitting hole 89 of the upper membrane module
34 from below and the upper coupling surface 49 of the
lower membrane module 34 and the lower coupling surface
50 of the upper membrane module 34 are set in contact
with each other. Consequently, as shown in FIG. 34, the
lower membrane module 34 and the upper membrane module 34
adjacent to each other are coupled via the coupling
portions 151. It is possible to prevent the upper
membrane module 34 from disengaging from the lower
membrane module 34 in the front-back direction B and the
left-right direction C (an example of the direction
orthogonal to the predetermined arrangement direction
(the up-down direction A)).
In this way, it is possible to easily couple the
plurality of upper and lower membrane modules 34 to form
a membrane cassette 31. The water collecting spaces 43 of
the plurality of upper and lower membrane modules 34
coupled to each other communicate with each other via
flow holes 99 of the coupling portions 151.
In some cases, the dimensions of the membrane module
34 are different between during manufacture and after use,
because of contained water, a temperature change and the
like due to the use in a liquid to be treated 33. An
error may occur between a space Dl between the fitting
projection 88 of the one water collecting case 35a and
the fitting projection 88 of the other water collecting
case 35b and a space D2 between the fitting hole 89 of
the one water collecting case 35a and the fitting hole 89
of the other water collecting case 35b.
In such a case, when the membrane module 34 already
used and the membrane module 34 not used are vertically
stacked and coupled via the coupling portions 151, as
indicated by an imaginary line of FIG. 32, the tubular
member 154 of the upper membrane module 34 slides in the
front-back direction B or the left-right direction C to
be displaced while keeping water tightness with a lower
coupling surface 150. Consequently, the error between the
space Dl between the left and right fitting projections
88 and the space D2 between the left and right fitting
holes 89 is absorbed. It is possible to surely insert the
fitting projections 88 of the lower membrane module 34
into the fitting holes 89 of the upper membrane module 34
An eighth embodiment of the present invention is
explained below on the basis of FIGS. 35 to 37.
A coupling portion 166 includes a fitting recess 167,
a fitting projection 168 that can be detachably fit into
the fitting recess 167, and upper and lower flow holes
169 and 170. The fitting recess 167 is formed in a lower
coupling surface 50 of each of water collecting cases 35a
and 35b. The fitting projection 168 is formed on an upper
coupling surface 49 of each of the water collecting cases
3 5a and 3 5b.
The upper flow hole 169 is formed in an upper plate
37 of each of the water collecting cases 35a and 35b and
opened to the upper coupling surface 4 9 and a water
collecting space 43. The fitting projection 168 is formed
in an annular shape to surround the outer circumference
of the upper flow hole 169.
The lower flow hole 170 is formed in a lower plate 38
of each of the water collecting cases 35a and 35b and
opened to the lower coupling surface 50 and the water
collecting space 43. The fitting recess 167 is formed in
an annular shape to surround the outer circumference of
the lower flow hole 170.
The fitting projection 168 can be detachably fit into
the fitting recess 167 in an up-down direction A. A seal
member 173 (e.g., an 0 ring) for sealing between an upper
inner surface 171 (inner bottom surface) of the fitting
recess 167 and an upper end face 172 (distal end surface)
of the fitting projection 168 is provided on the fitting
projection 168.
The outer diameter of the fitting recess 167 is set
larger than the outer diameter of the fitting projection
168. The inner diameter of the fitting projection 168 is
set larger than the inner diameter of the fitting recess
167. Consequently, the fitting projection 168 can be
displaced within a predetermined range F in a front-back
direction B and a left-right direction C with respect to
the fitting recess 167 in a state in which the fitting
projection 168 is fit into the fitting recess 167. The
predetermined range F is equivalent to smaller one of a
difference obtained by subtracting the outer diameter of
the fitting projection 168 from the outer diameter of the
fitting recess 167 and a difference obtained by
subtracting the inner diameter of the fitting recess 167
from the inner diameter of the fitting projection 168.
Operations in the configuration are explained below.
When a plurality of membrane modules 34 are
vertically stacked, the fitting projection 168 of the
lower membrane module 34 is fit into the fitting recess
167 from below to join the upper coupling surface 49 of
the lower membrane module 34 and the lower coupling
surface 50 of the upper membrane module 34. Consequently,
as shown in FIG. 37, the lower membrane module 34 and the
upper membrane module 34 adjacent to each other are
coupled via the coupling portions 166. It is possible to
prevent the upper membrane module 34 from disengaging
from the lower membrane module 3 4 in the front-back
direction B and the left-right direction C (an example of
the direction orthogonal to the predetermined arrangement
direction (the up-down direction A)).
In this way, it is possible to easily couple the
plurality of upper and lower membrane modules 34 to form
a membrane cassette 31. The water collecting spaces 43 of
the plurality of upper and lower membrane modules 34
coupled to each other communicate with each other via the
upper and lower flow holes 169 and 170.
An error may occur between a space Dl between the
fitting projection 168 of the one water collecting case
35a and the fitting projection 168 of the other water
collecting case 35b and a space D2 between the fitting
recess 167 of the one water collecting case 35a and the
fitting recess 167 of the other water collecting case 35b.
In such a case, when the plurality of membrane
modules 34 are vertically stacked and coupled via the
coupling portions 166, if the positions of the fitting
projections 168 are deviated with respect to the
positions of the fitting recesses 167 within the
predetermined range F, the fitting projection 168 of the
lower membrane module 34 can be fit into the fitting
recess 167 of the upper membrane module 34. Consequently,
the error between the space Dl between the left and right
fitting projections 168 and the space D2 between the left
and right fitting holes 53 is absorbed. It is possible to
surely insert the fitting projection 168 of the lower
membrane module 34 into the fitting recess 167 of the
upper membrane module 34. Water tightness is kept by the
seal member 173 between the upper coupling surface 49 of
the lower membrane module 34 and the lower coupling
surface 50 of the upper membrane module 34.
In the first embodiment, as shown in FIG. 3, a
fitting projection 52 is provided on the upper plate 37
of each of the water collecting cases 35a and 35b, a
fitting hole 53 is provided on the lower plate 38 of each
of the water collecting cases 35a and 35b, and the
plurality of membrane modules 34 are stacked and coupled
in the up-down direction A. However, the position where
the fitting projection 52 is attached is not limited to
the upper plate 37. The position where the fitting hole
53 is formed is not limited to the lower plate 38. For
example, the fitting projection 52 may be provided on the
lower plate 3 8 and the fitting hole 53 may be provided on
the upper plate 37.
in a ninth embodiment, as shown in FIG. 38, a fitting
projection 52 may be provided on a front plate 3 9 of each
of water collecting cases 35a and 35b and a fitting hole
53 may be provided in a rear plate 40 of each of the
water collecting cases 35a and 35b. In this case, a
plurality of membrane modules 34 are arranged and coupled
in a front-back direction B (predetermined arrangement
direction). The fitting projection 52 of the one water
collecting case 3 5a on the left or right of the membrane
module 34 located at the forefront end and one water
collecting pipe 59 on the left or right are connected via
a connection pipe 60. Similarly, the fitting projection
52 of the other water collecting case 35b on the left or
right thereof and the other water collecting pipe 59 on
the left or right thereof are connected via the
connection pipe 60. In the second to eighth embodiments,
as in the ninth embodiment, the plurality of membrane
modules 34 may be arranged and coupled in the front-back
direction B.
In a tenth embodiment, as shown in FIG. 39, fitting
projections 52 may be provided on an upper plate 3 7 and a
front plate 39 of each of water collecting cases 35a and
35b and fitting holes 53 may be provided on a lower plate
38 and a rear plate 40 of each of the water collecting
cases 35a and 35b. In this case, a plurality of membrane
modules 34 can be arranged and coupled in two directions
of an up-down direction A and a front-rear direction B.
In the second to eighth embodiments, as in the tenth
embodiment, the plurality of membrane modules 34 may be
arranged and coupled in the two directions of the up-down
direction A and the front-rear direction B.
In the foregoing embodiments, the water collecting
cases 3 5a and 3 5b of the top membrane module 34 are
connected to the water collecting pipes 59 via the
connection pipes 60. However, the water collecting pipes
59 may be provided in the lower part of the treatment
tank 32 and the water collecting cases 35a and 35b of the
bottom membrane module 34 may be connected to the water
collecting pipes 59 via the connection pipes 60. At least
one point of the water collecting cases 35a and 35b only
has to be connected to the water collecting pipes 59. The
connection pipes 6 0 do not have to be used.
In the foregoing embodiments, the projection inclined
surfaces 54, 79, 105, and 133 are provided in the fitting
projections 52, 75, 76, 88, and 111 and the hole inclined
surfaces 55, 84, 85, 106, and 134 are provided in the
fitting holes 53, 72, 73, 89, and 112. However, the
advantages can be obtained even when the projection
inclined surfaces 54, 79, 105, and 133 or the hole
inclined surfaces 55, 84, 85, 106, and 134 are provided.
In the foregoing embodiments, the coupling potions 51,
70, 87, 110, 141, 145, 151, and 166 are formed in a
cylindrical shape. However, the shape of the coupling
potions 51, 70, 87, 110, 141, 145, 151, and 166 is not
limited to the cylindrical shape. For example, the shape
may be a square cylinder shape, a triangle cylinder shape,
or other shapes.
In the third and fourth embodiments, only the fitting
projections 88 and 111 are displaceably held by the
holding mechanisms 92 and 116. However, both of the
fitting projections 88 and 111 and the tubular members
101 and 128 may be displaceably held respectively by
holding mechanisms.
In the seventh embodiment, only the tubular member
154 is displaceably held by the holding mechanism 157.
However, both of the fitting projection 88 and the
tubular member 154 may be displaceably held respectively
by holding mechanisms.
WE CLAIM:
1.A membrane module that is immersed in a liquid to be
treated and performs filtration, comprising:
a pair of water collecting cases; and at least one
membrane element provided between the pair of water
collecting cases, wherein
water collecting spaces in which permeate having
permeated through the membrane element is collected are
formed in the water collecting cases,
the water collecting cases can be coupled via
coupling portions to water collecting cases of another
membrane module adjacent to the membrane module in a
predetermined arrangement direction,
the coupling portions have flow holes, and
the water collecting spaces communicate with water
collecting spaces of the water collecting cases of the
other membrane module via the flow holes of the coupling
portions.
2.The membrane module according to claim 1, wherein the
coupling portions have fitting holes or fitting recesses
and fitting projections that can be detachably fit into
the fitting holes or the fitting recesses in the
predetermined arrangement direction.
3.The membrane module according to claim 2, wherein at
least one of the fitting projections and the fitting
holes are displaceable within a predetermined range in a
direction orthogonal to the predetermined arrangement
direction while keeping water tightness with the water
collecting spaces with which the membrane modules
communicate.
4.The membrane module according to claim 3, wherein the
coupling portions include tubular members having the
fitting holes and holding mechanisms for holding at least
one of the fitting projections and the tubular members to
be displaceable within the predetermined range in the
orthogonal direction.
5.The membrane module according to claim 4, wherein
the holding mechanisms include annular
circumferential wall portions provided in the water
collecting cases, annular inner brim portions projecting
from ends of the circumferential wall portions to an
inner side in a radial direction, and holding spaces
formed between the water collecting cases and the inner
brim portions,
the fitting projections include outer brim portions
projecting to an outer side in the radial direction and
are inserted into the inner sides of the circumferential
wall portions, and
the outer brim portions of the fitting projections
are inserted into the holding spaces.
6.The membrane module according to claim 4, wherein
the holding mechanisms include tubular
circumferential wall portions provided in the water
collecting cases, holding grooves formed in the
circumferential wall portions, and holding pawls provided
in the fitting projections,
the fitting projections are inserted into inner sides
of the circumferential wall portions, and
the holding pawls project to the outer side in the
radial direction of the fitting projections and are
inserted into the holding grooves.
7.The membrane module according to any one of claims 2
to 6, comprising at least one of a projection inclined
surface formed in a distal end portion of the fitting
projection and narrowed in the radial direction toward a
distal end and a hole inclined surface formed in an outer
end portion of the fitting hole and expanded in the
radial direction toward an outer end.
8. A membrane cassette in which the plurality of
membrane modules according to any one of claims 1 to 7
are arrayed in the predetermined arrangement direction,
wherein
the water collecting cases of the membrane modules
adjacent to each other are detachably coupled via the
coupling portions, and
the water collecting spaces of the membrane modules
adjacent to each other communicate with each other via
the flow holes.

A membrane element is provided between a pair of
water collecting cases. Water collecting spaces in which
permeate having penetrated through the membrane element
is collected are formed in the water collecting cases.
The water collecting case of one membrane module and the
water collecting case of the other membrane module are
coupled via coupling portions. The coupling portions have
flow holes. The water collecting space of the water
collecting case of the one membrane module and the water
collecting space of the water collecting case of the
other membrane module communicate with each other via the
flow holes of the coupling portions.