Patent Application
20190030472
The present invention relates to a filtration device comprising a filter housing and a replaceable filter cartridge housed in the filter housing, the filtration device being configured to filter liquid by passing it through a filter portion of the filter cartridge. More particularly, the present invention proposes a technique capable of replacing the filter cartridge and stably holding the filter cartridge in the filter housing even under certain restrictions on an arrangement space of the filter device.
This type of filtration device generally comprises a filter housing having a head provided with an inflow port and an outflow port through which liquid flows in or flows out, as well as a cylindrical bowl with a bottom, removably connected to the head; and a filter cartridge housed in the filter housing, and the device being used, for example in a filtration process for filtering pure water, chemical liquid, or the like, employed during manufacturing of semiconductors, electronic parts, and other various materials.
In such a filtration process, the use of the filtration device for a certain period of time will lead to decreased collection performance of contaminants due to adhesion of the contaminants contained in wastewater to be filtered to particularly a filter portion of the filter cartridge. Therefore, it is necessary to replace the filter cartridge with a new one in order to obtain high-purity liquid or the like required for the filtration process when a certain period of service of the filtration device has elapsed.
If the filter cartridge of the filtering device has a structure in which the filter cartridge is suspended from a head side of the filter housing and is removably fixed, a bowl of the filter housing is first removed from the head disposed at a position where the above filtering process is performed, in order to replace the filter cartridge. The filter cartridge, suspended from and fixed to the head, is then removed. In this case, when removing the bowl from the head, it is necessary to move the bowl downward away from the head along the axial direction of the housing until the entire filter cartridge present inside the bowl are exposed. Therefore, for such a filtration device, it will be difficult to replace the filter cartridge if, in the arrangement space of the filter device, a space corresponding to the length of the filter cartridge in the axial direction of the housing, in addition to the length of the bowl in the axial direction of the housing, is not ensured on the lower side of the bowl.
With respect to this, Patent Document 1 discloses “a mass transfer or energy transfer cartridge which comprises: an elongated medium capable of effecting mass transfer therethrough or for effecting energy transfer from a first fluid to a second fluid, said elongated medium having a first end and a second end, a first sealing plate sealed to said first end, a second sealing plate having a fluid passageway having a fluid passage sealed to said second end, a fluid passageway sealed to said first sealing plate to provide fluid communication to an open interior within said medium, and said first sealing plate having at least two flanges which extend beyond an outer surface of said medium”, in order to “reduce the space required to install the mass transfer or energy transfer module” and the like. Similar techniques are also disclosed in Patent Documents 2 and 3, and the like.
Patent Document 1: Japanese Patent Application Public Disclosure (KOHYO) No. 2008-505760 A1. Patent Document 2: Japanese Patent No. 4266833 B1. Patent Document 3: Japanese Patent No. 4664596 B1.
The “mass transfer or energy transfer cartridge” described in Patent Document 1 causes a problem that when performing the filtration, unintended displacement of the filter cartridge in the rotational direction occurs and the filter cartridge sways, so that any stable filtration cannot be carried out, because the filter cartridge is not securely fixed to the inside of the filter housing, particularly in the rotational direction about the housing axis.
Further, in Patent Documents 2 and 3, the “collar” is made of a flexible material, so that when removing the filter cartridge together with the bowl, the filter cartridge and the bowl may be detached from each another by force in the rotational direction which can act on the filter cartridge. In this case, when the bowl is detached, the filter cartridge is still connected to and remains on the head side. Therefore, this device requires the ensuring of the space as described above as well as the movement of the displacement in the rotational direction of the filter cartridge cannot be sufficiently restricted.
An object of the present invention is to solve the above problems, and to provide a filtration device that can reduce a space required for replacing a filter cartridge and stably fix the filter cartridge in a filter housing.
A filtration device of the present invention comprises a filter housing having a head, and a cylindrical bowl with a bottom, removably connected to the head; and a filter cartridge housed in the filter housing and having a filter portion, the filtration device being configured to allow liquid flowing in from an inflow port of the head to pass through the filter portion of the filter cartridge and allow the liquid to flow out of an outflow port of the head to filter the liquid, wherein the filter housing comprises at least one axial direction stopper for restricting displacement of the filter cartridge in a housing axial direction and at least one rotational direction stopper for restricting displacement of the filter cartridge in a rotational direction around a housing axis, and wherein the filter cartridge is removably secured to the bowl within the filter housing by the at least one axial direction stopper and the at least one rotational direction stopper.
In the filtration device according to the present invention, the filter cartridge may further preferably include at least one outward flange portion protruding toward the side of the bowl, and the bowl may preferably comprise at least one flange engaging portion that interposes the at least one outward flange portion from both sides in the housing axial direction, as the at least one axial direction stopper.
Further, in the filtration device according to the present invention, the filter housing may further include a stopper member that is engaged with each of the filter cartridge and the bowl, and the rotational direction stopper may be composed of at least one convex portion that is provided on one of the stopper member and the bowl and at least one concave portion that is provided on the other of the stopper member and the bowl and that interposes the at least one convex portion from both sides in the rotational direction.
In this case, it is preferable that each of the bowl and the stopper member may be provided with at least one pair of vertical wall surfaces interposing the outward flange portion from both sides in the rotational direction. Alternatively, it is preferable that the stopper member and the filter cartridge are engageable with each other by inserting at least one pin provided on one of the stopper member and the filter cartridge into at least one pin hole provided on the other.
Further, it is preferable that the at least one pin hole is provided on the at least one outward flange portion of the filter cartridge, the at least one concave portion is provided on the bowl, the stopper member disposed on the filter cartridge on the head side in the filter housing is annular, and the at least one convex portion is provided on the annular stopper member so as to protrude radially outward and the at least one pin is provided on the at least one convex portion of the stopper member so as to extend toward the side of the outward flange portion.
It is preferable that the at least one pin is inserted into and engaged with the at least one pin hole by press fitting. Specifically, it is preferable that the at least one pin has a head portion with increased diameter as compared to the other portion at a tip portion of the pin. It is preferable that the at least one convex portion is inserted into and frictionally engaged with the at least one concave portion by press fitting.
It is preferable that the stopper member is engagable with each of the filter cartridge and the bowl at two or more positions. Further, it is preferable that the portions of the stopper member to be engaged with each of the filter cartridge and the bowl are formed integrally with the stopper member.
It is preferable that the filtration device according to the present invention further comprises a connecting ring on an abutting position between the head of the filter housing and the bowl, wherein the connecting ring surrounds the abutting position from its outer side to connect the head and the bowl to each other, and wherein the bowl is detachable from the head together with the filter cartridge by removing the connecting ring.
According to the filtration device of the present invention, the filter housing is provided with the at least one axial direction stopper and the at least one rotational direction stopper, whereby the filter cartridge can be stably secured into the filter housing without wobbling in those directions. Further, according to the filtration device of the present invention, the filter cartridge is detachably secured to the bowl by the at least one axial direction stopper and the at least one rotational direction stopper, so that the bowl can be detached from the head together with the filter cartridge secured to the inside of the bowl, thereby reducing the space required for replacing work of the filter cartridge.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. A filtration device 1 illustrated in
In the illustrated embodiment, as shown in
Further, in the illustrated embodiment, the filter cartridge 20 may include a substantially cylindrical body portion 20a; and a bottom portion 20b provided on one end side of the body portion 20a, which side is the same as that of the bottom portion 11b of bowl 11 in the housing axial direction, and the filter cartridge 20 may also comprise an opening 20c on the other end side of the body portion 20a in the housing axial direction. In this case, the greater part of the filter cartridge 20 is positioned on the side of the bowl 11 inside the filter housing 10. The filter cartridge 20 is provided with a filter portion arrangement space 21 in the body portion 20a, and within the filter portion arrangement space 21a is a filter portion (not shown) for allowing the liquid flowing into the filter housing 10 to pass through. In addition, the cylindrical portion forming the body portion 20a is provided with a large number of openings through which liquid can pass.
Such a filtration device 1 may be used for filtering liquid such as ultrapure water and chemical liquid employed during production of semiconductors, microelectronics or the like, for example. In order to filter such liquid using the filtration device 1, certain liquid flowing into the head 13 from the inflow port 14 of the head 13 may flow toward the bowl 11 side, for example. The liquid may then pass through the body portion 20a from an outer circumference side to an inner circumference side of the filter cartridge 20, and contaminants in the liquid may be removed at the filter portion of the filter portion arrangement space 21 inside the body portion 20a. The liquid may then flow from the inside of the filter cartridge 20 to the inside of the head 13 and flow out of the filter housing 10 through the outflow port 15. However, this filtration method using the filtration device 1 is illustrative only, and the present invention is not limited to such a filtration method.
If the filtering device 1 is repeatedly used by the method as stated above, filtration performance of the filtration device 1 may be deteriorated because substances to be removed such as contaminants that may be contained in the above liquid adhere to the filter cartridge 20, in particular the filter portion. Therefore, it will be necessary to replace the filter cartridge 20 after using the filtration device 1 for a certain period of time or a certain number of times in order to always obtain a filtrate satisfying a predetermined high level of requirement.
Here, for the replacement of the filter cartridge, if the filter cartridge is structured to be attached to the head side in the filter housing, the bowl of the filter housing is detached by firstly disconnecting the bowl from the head, and then moving the bowl in a direction away from the head along the housing axial direction at a distance greater than or equal to the length in the housing axial direction of the filter cartridge until the filter cartridge extending to the inner side of the bowl is fully exposed. This structure causes a problem of depending on constraints on the arrangement space for the filtration device, which problem is that the bowl cannot be detached before replacing the filter cartridge if there is no sufficient space on the bottom side of the bowl of the filter housing to move the bowl for the longer distance as described above.
In order to address this problem, the present invention provides the filter cartridge 20 detachably secured to the bowl 11 inside the filter housing 10, as shown in
Further, according to the present invention, the filter housing 10 may be provided with at least one axial direction stopper for restricting displacement of the filter cartridge 20 in the housing axial direction and at least one rotational direction stopper for restricting displacement of the filter cartridge 20 in the rotational direction around the housing axis AD, in order to stably maintain the filter cartridge 20 in the filter housing 10. Therefore, when the filter cartridge 20 is housed in the filter housing 10, the displacement in both the housing axial direction and the rotational direction around the housing axis AD can be restricted to prevent unintentional shaking, so that as a further effect, the filtration of liquid can be stably carried out.
More particularly, in this embodiment, the filter cartridge 20 may include at least one plate-shaped outward flange 22 (four plate-shaped outward flanges 22 in the figure) on an outside edge surrounding the opening 20c, the outward flange 22 extending from the side edge toward the outer peripheral side, and the axial direction stopper as described above can be composed of at least one flange engaging portion 17 provided on an outside edge of the opening 11c on the other end side of the bowl 11. In this case, the outward flange portion 22 can be integrally formed with the filter cartridge 20 as shown in the illustrated embodiment.
For example, as shown in the partially enlarged view of
In the illustrated embodiment, the vertical walls 11d are integrally formed with the bowl 11, and the outward flange portions 22 are directly connected to the flange engaging portions 17 provided on the vertical walls 11d without directly interposing other member(s).
In this embodiment, the outer surface of the stopper member 16 presenting a ring shape such as an annular shape is provided with at least one convex portion 16a protruding outward in the radial direction of the stopper member 16, as shown in
In the illustrated embodiment, each concave portion 18 provided by notching a part of the top surface side of the vertical wall 11d is more preferably slightly narrower than the width of the convex portion 16a, whereby the convex portion 16a can be inserted by press fitting to be frictionally engaged with the convex portion 16a. In such a way, the stopper member 16 can be strongly engaged with the bowl 11 so that any displacement in the rotational direction of the stopper member 16 and the filter cartridge 20 relative to the filter housing 10 can be more reliably prevented. Alternatively, although not shown in the drawings, the concave portions may be formed as depressions provided on the inner surfaces of the vertical walls without piercing the vertical walls, and the two convex portions positioned on a straight line orthogonal to the central axis of the stopper member may be press-fitted between the inner surfaces of the corresponding two concave portions, whereby the two convex portions can be frictionally engaged with the two concave portions by stretching the convex portions between the two concave portions in the radial direction of the bowl. In this case, the internal filter cartridge is held by the stopper member having the two convex portions frictionally engaged between the two concave portions, so that pins and pin holes described below will not be required. When frictionally engaged in such a way, three or more concave and convex portions may be provided.
However, each concave portion 18 may be at least brought into contact with each convex portion 16a from both sides of the concave portion 18 in the rotational direction so as to have the respective abutting surfaces 18a and 18b which interpose the convex portion 16a from both sides in the rotational direction, as shown in
Further, as shown in
The pins 16b and the pin holes 22a may be only required to engage with each other when the stopper member 16 is disposed on the filter cartridge 20, and their arrangement positions are not particularly limited. Therefore, it is also possible to provide the pins at the convex portions of the stopper member if the positions of the pin holes of the outward flange portion 22 are shifted to the outer peripheral side, although not shown in the figure.
When the pins 16b and the pin holes 22a are provided and these are used for engagement between the stopper member 16 and the filter cartridge 20, it is preferable to have a structure in which the pins 16b are press-fitted and inserted into the pin holes 22a, in order to firmly engage the stopper member 16 with the filter cartridge 20. This can be achieved, such as by forming the pins 16b each having a spherical head with larger diameter than that of the other portions at the tip portion of each pin 16b, and slightly increasing the maximum diameter of the head as compared with the inner diameter of each pin hole 22a.
Such a structure of the stopper member 16 serves not only as a stopper in the rotational direction of the filter cartridge 20 but also to provide engagement between the stopper member 16 and the bowl 11. The convex portions 16a as the engaging portions may be preferably formed integrally with the stopper member 16 as shown in the illustrated embodiment, in terms of reduction of the number of members and ease of assembly and the like. Although not shown in the drawing, the convex portions may be provided on the bowl side and the concave portions may be provided on the stopper member side.
It is preferable to provide two or more engaging portions of the stopper member 16 with the filter cartridge 20 and the bowl 11, such as the pins 16b and the pin holes 22a or the convex portions 16a and the concave portions 18 as described above. Thus, the engagement of the stopper member 16 with each of the filter cartridge 20 and the bowl 11 can be strengthened. In the illustrated embodiment, the two pins 16b and the two pin holes 22a are engaged with each other, as well as the two convex portions 16a and the two concave portions 18 are engaged with each other.
By assembling the bowl 11, the stopper member 16 and the filter cartridge 20 as described above, the cartridge-housed bowl 30 as shown in
Further, each outward flange portion 22 of the filter cartridge 20 herein gets caught in the flange engaging portions 17 of the bowl 11. This can prevent any displacement of the filter housing 10 in the axial direction of the housing. Consequently, the filter cartridge 20 can be secured to the side of the bowl 11 and stably held in the filter housing 10.
To assemble the cartridge-hosed bowl 30 as shown in
As shown by the arrow in
As shown in
In addition, when attaching the above cartridge-housed bowl 30 to the head 13, the outer peripheral sides of the vertical walls 11d of the bowl 11 are surrounded by an O ring 13a of the head 13, and the cartridge-housed bowl 30 is inserted into the inside of the head 13 such that the opening 13c of the bowl 11 is covered with the head 13, as shown in
In this state, the connecting ring 12 provided with thread grooves or thread ridges on the inner circumferential surface is brought onto the outer circumferential side of the bowl 11 from the bottom portion 11b side, and the connecting ring 12 is disposed so as to surround the annular flange 11f of the bowl 11 while contacting the inner flange portion 12a on one end side of the connecting ring 12 with the annular flange 11f, and the thread grooves or thread ridges on the connecting ring 12 are screwed to corresponding thread ridges or thread grooves provided on the outer circumferential side of the O ring 13a of the head 13. In such a way, the annular flange 11f of the bowl 11 can be sandwiched between the inner flange portion 12a of the connection ring 12 and the O ring 13a of the head 13 screwed into the connection ring 12 to connect the head 13 and the cartridge-housed bowl 30 to each other. The use of such a connecting ring 12 provides an advantage that the bowl 11 can be easily detached from the head 13 together with the filter cartridge 20.
Further, the O ring 13a of the head 13 and the O ring 23 of the bowl 11 can ensure a liquid-tight property at a position where leakage of liquid should be prevented. The stopper member 16 may be provided with one through hole 16c or a plurality of through holes 16c at predetermined intervals along the circumferential direction of the annular stopper member 16, which through hole(s) 16c allow(s) the liquid flowing into the head 13 to flow through the interior of the bowl 11 side. Further, here, each of the through holes of the stopper member 16 is provided with a reinforcing rib that extends toward the annular part on the outer peripheral side of the though hole and has a triangular shape as viewed from the side, in order to prevent the reduction of strength of the stopper member 16 due to the arrangement of the through holes 16c.
The bottom portion 11b of the bowl 11 may be provided with a drain 11g for discharging liquid out of the filtration device 1 during discharging effluent from the device, and the inflow port 14 side and the outflow port 15 side may be provided with vent holes 13c and 13d, respectively, for allowing the flowing of a gas inside and outside the filtration device 1 during discharging the liquid from the drain 11g. During normal use of the filtration device 1, these drains 11g and vent holes 13c, 13d are hermetically sealed by attaching a cap (not shown).
The head 13, the bowl 11, the stopper member 16 and the body portion 20a of the filter cartridge 20 among the respective elements for the filtration device 1 may be made of any materials as long as they are resistant to the liquid to be filtered, including plastics (preferably polyethylene including ultrahigh molecular weight polyethylene, polypropylene, PTFE, PFA, PVDF and other fluorine resins, polycarbonates, polysulfones, and polyethersulfones). Materials of the head 13 and the bowl 11 may be selected from desired materials depending on their applications, including, in addition to the above-listed materials, glass, or metals such as stainless steel, aluminum, copper, nickel, chromium, titanium, or alloys or mixtures thereof. Further, the filter portion of the filter cartridge 20 may be made of any material ordinarily used for the filtration, such as paper, cellulosic materials, glass fibers and fabrics, metals such as stainless steel, nickel, chromium, and alloys and mixtures thereof, ceramics, plastics, and preferably thermoplastic materials including materials listed below, and the like. The thermoplastic materials include polyethylene such as ultrahigh molecular weight polyethylene, polypropylene, PVDF, PTFE, PFA and other fluorine resins, PCV, nylons, polyamides, polysulfones, polyimides, polycarbonates, PET and the like.
That is, in this embodiment, concave portions 180 are provided on vertical walls 111d provided with flange engaging portions 170 among the vertical walls 111d of a bowl 111, as shown in
In such a bowl 111, a filter cartridge is arranged and a stopper member 160 is attached. As shown in
In the embodiment as shown in
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/063046 | 4/30/2015 | WO | 00 |
