JP2008264603A - Filter cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter cartridge capable of enhancing air removing performance to a central part inside flow passage. <P>SOLUTION: The filter cartridge 1 is constituted so that a central space of a cylindrical filter member 11 is split into an inner flow passage 40 connected to an inlet 31 and an outer flow passage 43 connected to an outlet 32, the liquid to be filtered introduced from the inlet 31 flows to a bottom 41 at a lower part of the filter member passing through the inner flow passage 40, then to an outer space 42 in the radial direction of the filter member 11, flows to a center in the filter member 11, filtrate passes through the outer flow passage 43 to be discharged from the outlet 32, wherein a spiral groove 50 is formed at a downstream side portion of an inner peripheral wall face 14' of an inner cylinder 14 forming the inner flow passage 40. The flow of the filtrate flowing through the inner flow passage 40 from the groove 50 is made turbulent to prevent occurrence of a laminar flow, allowing bubbles to hardly remain on the inner peripheral wall face 14'. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a filter cartridge, and more specifically, an amine-based organic stripping solution or a pigment-dispersed photoresist used when manufacturing a semiconductor wafer, a glass substrate for LCD, or the like, or a slurry used when using a chemical mechanical polishing apparatus. The present invention relates to a filter cartridge for use in filtration of water, production of pure water, etc., and particularly to its structure.

  A filter cartridge (hereinafter, also simply referred to as “cartridge”) includes a filter assembly, a housing (bowl) for housing the filter assembly, a housing lid body having a filtrate inlet, a filtrate outlet, and a vent. The filter assembly includes a filter member in which a porous membrane with a pleat fold is formed into a cylindrical shape and is accommodated between inner and outer porous cylinders, and upper and lower end caps are fused. .

  In some cartridges, the liquid to be filtered is first introduced from the inlet into the radially outer space of the filter member, then passed through the filter member from here to the central portion, and discharged from the central portion to the outlet (for example, Japanese Patent Application Laid-Open No. Hei. No. 5-329337, Japanese Patent Application Laid-Open No. 2004-130253, etc.). In this type of cartridge, the flow of the liquid to be filtered tends to stagnate on the bottom side of the housing in the radially outer space of the filter member. Therefore, unfiltered foreign matter remains near the bottom, or the bottom side of the filter member is on the top side (housing Use efficiency may be lower than that on the lid side.

In order to improve this point, the central space of the filter member is divided into a radially inner central portion inner flow path (hereinafter also simply referred to as “inner flow path”) and a radially outer central portion outer flow path ( Hereinafter, the liquid to be filtered introduced from the inlet is first passed through the inner channel and then sent from the bottom of the housing to the radially outer space of the filter member. There is known a filter cartridge configured to prevent stagnation here, pass the filter member uniformly from here to the center, and discharge the filtrate from the outlet through the outer flow path.
JP-A-5-329337 JP 2004-130253 A

  In this type of cartridge, it is necessary to completely remove air (bubbles) from the inner flow path at the initial stage of introduction of the filtrate to be filtered. A defect may occur in a semiconductor wafer or the like being manufactured. First, most of the air present in the inner flow path is pushed out of the inner flow path by introduction of the liquid to be filtered, and is discharged to the outside of the housing through the vent of the housing lid. In some cases, it remains attached to the downstream side (bottom side) of the wall surface forming the path. This is because the liquid flowing into the inner flow path from the inlet is relatively turbulent on the upstream side of the flow path and becomes a stable laminar flow as it goes downstream. In the laminar flow state on the downstream side of the flow path, Due to the viscosity of the liquid with respect to the flow path wall, a velocity gradient is generated along the horizontal section with a slower flow rate radially outward than the center of the flow, so that the buoyancy of the bubbles and the low velocity flow along the wall surface will push the bubbles. This is thought to be due to the balance between the power of

  Note that if the flow rate or flow rate of the liquid in the inner flow path is increased, the air removal performance will also be improved, but the flow rate and flow rate will be reduced depending on the strength and shape of the cartridge components or the relationship with other devices to which the cartridge is connected. There is a limit to the increase, and the laminar flow tends to occur on the downstream side of the inner flow path whose vertical length is longer than the horizontal cross section.

  This invention is made | formed in view of the above point, The objective is to provide the filter cartridge which can improve the air removal performance with respect to a center part inner side flow path.

  According to the present invention, the central space of the cylindrical filter member is divided into a radially inner central portion inner passage connected to the inlet and a radially outer central portion outer passage connected to the outlet, The liquid to be filtered introduced from the inlet passes through the central portion inner flow path to the bottom portion below the filter member, and then from the bottom portion to the radially outer space of the filter member, and then from the radially outer space to the central portion. In the filter cartridge configured to be filtered through the filter member and discharged from the outlet through the central outer channel, the downstream portion of the central inner channel is covered. A filter cartridge is provided, which is provided with means capable of disturbing the flow of the filtrate.

  In the present invention, the downstream portion in the central inner channel is a ½ portion on the bottom side from the axial middle of the inner channel, and preferably further on the bottom side from the middle of the ½ portion. Is a quarter part.

  As a means for disturbing the flow of the liquid to be filtered, it may be possible to arrange a separate member in the inner flow path, but it is provided directly on the inner flow path wall surface without processing a separate member (the wall surface is processed) Is desirable.

  In an embodiment of the present invention, the means is a concave portion and / or a convex portion provided on a wall surface forming the central portion inner passage. This concave and / or convex part interferes with the fluid along the wall on the downstream side of the inner flow path and partially disturbs the flow to prevent the generation of a stable laminar flow, that is, the flow velocity gradient, Makes it easy to be crushed by the flow. The pulverized bubbles have a reduced buoyancy and promote discharge.

  In an embodiment of the present invention, the concave portion and / or the convex portion are formed in a spiral shape. By making the concave portion and / or the convex portion into a spiral shape, a swirling turbulent flow is generated on the downstream side of the inner flow path, and bubbles are more easily crushed by the swirling flow. Further, since the die can be punched while rotating during the molding of the member constituting the inner flow path, the molding process is not complicated.

  In the present invention, by providing a means capable of disturbing the flow of the liquid to be filtered in the downstream portion of the central inner channel, the stable laminar flow in this portion is prevented and the flow along the horizontal cross section is prevented. To increase the flow velocity along the wall surface, make it difficult for bubbles to remain on the wall surface, and pulverize the bubbles with turbulent flow to reduce buoyancy and promote the discharge of bubbles. it can. In addition, since a stable laminar flow is more likely to occur as the axial length of the central portion inner flow path becomes longer, the longer the central portion inner flow path, the more effective the effect of the present invention.

  Hereinafter, a filter cartridge according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of the filter cartridge 1. The cartridge 1 includes a filter assembly 10, a housing (bowl) 20 that accommodates the filter assembly 10, a filtrate inlet 31 and an inlet flow path 31 ′ following it, a filtrate outlet 32, and a subsequent outlet. It is comprised from the flow-path 32 'and the housing cover body (head) 30 in which the vent 33 was integrated. The filter assembly 10 includes a filter member 11 formed by cylindrically forming a pleated fold porous film, a sleeve 12 that is a porous cylinder surrounding the filter member 11 in the radial direction, and a radially inner side of the filter member 11. The core 13 that is a surrounding porous cylinder, the inner cylinder 14 that is disposed at the inner center of the core 13, the upper end cap 15 that is fused to the top of the filter member 11, and the bottom of the filter member 11 are fused. And a bottom end cap 16. The core 13 and the inner cylinder 14 are an integral resin molded product, and the lower end portion of the core 13 and the lower end portion of the inner cylinder 14 are connected by a bottom plate 13 ′ and are closed during this time. The inside of the core 13 is divided by the inner cylinder 14 into an inner flow path 40 on the radially inner side and an outer flow path 43 on the outer side. The upper end portion of the inner cylinder 14 is connected to the inlet channel 31 ′, and the upper end portion of the core 13 excluding the portion corresponding to the inner cylinder 14 is connected to the outlet channel 32 ′. The flow path of the liquid in the filter cartridge 1 is as follows: inlet 31 → inlet channel 31 ′ → inner channel 40 → housing bottom 41 under the filter member → filter member radial outer space 42 → filter member 11 → outer channel 43 → The outlet flow path 32 ′ → the outlet 32. The upper end portion of the filter member radial direction outer space 42 is liquid-tight and air-tightly closed by the housing lid 30.

  Next, the characteristic part of the cartridge 1 will be described. The inner cylinder 14 has a constant inner diameter of 10 mm and an axial length of 100 mm. As an example, a spiral groove 50 is provided as a turbulent flow generating means in the downstream side of the inner wall surface 14 ′ of about 1/4 portion. Four are formed. The cross section of the groove 50 is substantially rectangular, the depth is 1 mm, the width is 1.5 mm, the horizontal inclination angle is 60 degrees, and the groove-to-groove pitch is 6.5 mm. The core 13 with the inner cylinder having such a groove 50 can be punched while being rotated at the time of molding.

  In the cartridge 1 configured as described above, when the liquid to be filtered introduced from the inlet 31 and the inlet flow path 31 ′ flows downward through the inner flow path 40, it interferes with the groove 50 and is downstream in the flow path 40. A swirling turbulent flow is generated at the side portion. Therefore, in this downstream portion, a stable laminar flow or flow velocity gradient does not occur, and bubbles do not easily remain on the inner cylinder wall surface 50, and the swirling flow crushes the bubbles to reduce buoyancy and discharge the bubbles. Prompt.

  In the above example, the spiral groove 50 is used as the turbulent flow generation means. However, the present invention is not limited to this, and convex portions are scattered on the inner cylinder wall surface 14 ', or the inner cylinder inner diameter of the downstream portion is changed to, for example, a wave shape. It may be something to be made.

It is a schematic longitudinal cross-sectional view of the filter cartridge which concerns on one Embodiment of this invention. FIG. 2 is an enlarged view of a downstream side portion of a central portion inner side flow path of the filter cartridge of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter cartridge 10 Filter assembly 11 Filter member 12 Sleeve 13 Core 14 Inner cylinder 20 Housing 30 Housing cover body 31 Inlet 32 Outlet 40 Inner flow path 43 Outer flow path 50 Groove

Claims (3)

The central space of the cylindrical filter member is divided into a radially inner central flow channel connected to the inlet and a radially outer central flow channel connected to the outlet. The filtrate passes through the filter member from the radially outer space to the center after passing through the center inner flow path to the bottom below the filter member and then from the bottom to the radially outer space of the filter member. In the filter cartridge configured such that the filtrate is discharged from the outlet through the central outer channel,
A filter cartridge comprising a means capable of disturbing a flow of a liquid to be filtered at a downstream portion of the central portion inner flow path.   2. The filter cartridge according to claim 1, wherein the means is a concave portion and / or a convex portion provided on a wall surface forming the central portion inner flow path.   The filter cartridge according to claim 2, wherein the concave portion and / or the convex portion are formed in a spiral shape.

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