Feed spacer and reverse osmosis filter module including same

Abstract

Provided is a feed spacer, in which angles of strands are differently formed in one feed spacer according to a flow direction of raw water, so that a differential pressure decrease region and a recovery increase region are separated to perform multiple functions, and a reverse osmosis filter module including the feed spacer.

Claims

1. A feed spacer, comprising: an area A and an area B, and each of area A and area B comprises: a first set, in which a plurality of strands is positioned in parallel; and a second set, in which a plurality of strands crosses the plurality of strands of the first set and is positioned in parallel, wherein: the strands of each of the first and the second set include a plurality of protruding portions having a diameter W2, and the protruding portions of the strands forming the first set cross the protruding portions of the strands forming the second set, thereby determining a thickness of the feed spacer, the strands of the first set and second set in area A include non-protruding portions having a diameter W1, the strands of the first set and second set in area B include non-protruding portions having a diameter W1′, a difference between the diameter W2 of the protruding portions and the diameter W1 of the non-protruding portions of the strands forming the area A is larger than a difference between the diameter W2 of the protruding portions and the diameter W1′ of the non-protruding portions of the strands forming the area B, a crossing angle a1 of the first set and the second set in area A is less than a crossing angle a2 of the first set and the second set in area B, and a cross-sectional area of a flow path in the area B is decreased with respect to a cross-sectional area of a flow path in area A.

2. The feed spacer of claim 1, wherein a distance between cross points of the first set and the second set in the area B is smaller than a distance between cross points of the first set and the second set in the area A.

3. A reverse osmosis filter module comprising the feed spacer of claim 1, wherein the area A is in a portion which is in first contact with raw water.

4. The reverse osmosis filter module of claim 3, wherein the reverse osmosis filter module includes: a tube including openings for accommodating a permeating liquid in a longitudinal direction; and one or more reverse osmosis membranes, which are extended from the tube in an outside direction and are wound around a circumference of the tube, and the feed spacer is in contact with the one or more reverse osmosis membranes and is wound around the circumference of the tube.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a top plan view of a feed spacer according to an exemplary embodiment of the present invention.

(2) FIG. 2 is a perspective view of the feed spacer according to the exemplary embodiment of the present invention.

(3) (a) of FIG. 3 is an enlarged view of a strand of portion A of FIG. 1, and (b) of FIG. 3 is an enlarged view of a strand of portion B of FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

(4) The present invention will be described in detail with reference to the accompanying drawings. Herein, repeated description, and a detailed description of a publicly known function and configuration which may unnecessarily make the main point of the present invention be unclear will be omitted. The exemplary embodiments of the present invention are provided for completely explaining the present invention to those skilled in the art. Accordingly, shapes, sizes, and the like of the elements in the drawings may be exaggerated for clear description.

(5) In the entire specification, unless explicitly described to the contrary, when it is said that a part “comprises/includes” a constituent element, this means that another constituent element may be further “included/comprised”, not that another constituent element is excluded.

(6) Hereinafter, an exemplary embodiment is presented for helping understanding of the present invention. However, the exemplary embodiment below is simply provided for easier understanding of the present invention, and the contents of the present invention are not limited by the exemplary embodiment.

(7) Feed Spacer

(8) FIG. 1 is a top plan view of a feed spacer according to an exemplary embodiment of the present invention, FIG. 2 is a perspective view of the feed spacer according to the exemplary embodiment of the present invention, and (a) of FIG. 3 is an enlarged view of a strand of portion A of FIG. 1, and (b) of FIG. 3 is an enlarged view of a strand of portion B of FIG. 1.

(9) The feed spacer according to the present invention can include a first set and a second set, in which a plurality of strands is positioned in parallel.

(10) In the first set, one or more strands can be positioned in parallel, and herein, the strand can be positioned to be inclined to a direction of raw water. Further, in the second set, one or more strands can also be positioned in parallel, and the second set can be positioned to cross the first set. Further, the second set is positioned with a direction of inclination opposite to a direction of inclination of the first set, so that the first set 10 and the second set 20 can be provided in a grating shape.

(11) Further, the first set 10 can be positioned at an angle of 10° to 80° to a flow direction of raw water, and the second set 20 can be positioned at an inclination of 100° to 170° to a flow direction of raw water. For example, when the strands forming the first set 10 are inclined at 30° to a flow direction of raw water, the strands of the second set 20 can be positioned while being inclined at 120° to the flow direction of raw water.

(12) In this case, when an angle formed between the first set 10 and the flow direction of raw water is less than 10°, a cross sectional area of a flow path formed by the strands is decreased and a laminar flow velocity gradient is not generated in a center portion of the feed spacer, so that there can be a problem in that a polarization phenomenon is increased, and when an angle formed between the first set 10 and the flow direction of raw water is larger than 80°, a cross sectional area of a flow path is decreased and the raw water actively flows in up and down directions, so that there can be a problem in that pressure loss is increased. Herein, the flow path is formed by the strands forming each set, and can mean a space between reverse osmosis membranes positioned in an upper portion and a lower portion of the feed spacer and each set.

(13) Further, in the feed spacer according to the present invention, a crossing angle of the first set 10 and the second set 20 can be different according to a flow direction of raw water. More particularly, an area A, in which a differential pressure is decreased, and an area B, in which recovery is increased, can be separated according to the angle between the first and second sets. The extents of the area, in which a differential pressure is decreased, and the area, in which recovery is increased, are not limited as long as the areas are capable of performing the functions.

(14) Further, the area A, in which a differential pressure is decreased, can be in a portion which is in first contact with raw water, and the area B, in which recovery is increased, can be positioned at one side of the area A according to a flow direction of the raw water.

(15) That is, the crossing angle of the first and second sets 10 and 20 can be increased according to the flow direction of the raw water. The angle can be gradually increased.

(16) Accordingly, the feed spacer according to the present invention can be formed with two stages. First stage is an area A, in which a differential pressure is decreased, and second stage is an area B, in which recovery is increased.

(17) In first stage, the crossing angle of the first and second sets 10 and 20 is a1, a distance of between cross points formed according to the cross of the first and second sets 10 and 20 is d1.

(18) In second stage, the crossing angle of the first and second sets 10 and 20 is a2, a distance of between cross points formed according to the cross of the first and second sets 10 and 20 is d2.

(19) a1 can be formed to be smaller than a2, and d1 can be formed to be larger than d2.

(20) That is, based on the same area, a density of the cross points in the area, in which the differential pressure is decreased, can be low, and a density of the cross points in the area, in which the recovery is increased, can be high.

(21) In the feed spacer according to the present invention, diameter ratios of the strands forming the first and second sets can be different according to the area, and diameters of the cross point and a non-cross point of the first and second sets 10 and 20 can be different. Referring to FIG. 2, a thickness of each of the strands forming the first and second sets 10 and 20 can be asymmetric, and this can mean that a protruding portion is formed at the center of the strand and a diameter of the strand is increased, so that the diameters of the protruding portion and a non-protruding portion are asymmetrically formed.

(22) In the exemplary embodiment, a diameter ratio of the strand forming the area A, in which the differential pressure is decreased, can be formed to be larger than a diameter ratio of the strand forming the area B, in which the recovery is increased. Referring to FIG. 3, a difference between a diameter W2 of the protruding portion and a diameter W1 of the non-protruding portion of the strand forming the area A, in which the differential pressure is decreased, can be formed to be larger than a difference between the diameter W2 of the protruding portion and a diameter W1′ of the non-protruding portion of the strand forming the area B, in which the recovery is increased. That is, the difference between the diameters of the strands at the cross point and the non-cross point can be decreased according to the flow direction of raw water.

(23) Further, the feed spacer according to the present invention has the same thickness regardless of the area. That is, the protruding portions of the first and second sets 10 and 20 can cross to form the feed spacer, and the diameters W2 of the protruding portions of the area, in which the differential pressure is decreased, and the area, in which the recovery is increased, can be formed to be the same. More particularly, in the first and second sets 10 and 20 according to the present invention, the protruding portion of the strand forming the first set 10 crosses the protruding portion of the strand forming the second set 20, thereby determining a thickness of the feed spacer. Accordingly, the difference between the diameter ratios of the strand forming each area can be adjusted by the non-protruding portions W1 and W1′.

(24) The feed spacer according to the present invention has an effect in that the plurality of functions and effects are achieved by using one feed spacer by adjusting angles a1 and a2 between the first and second sets 10 and 20 and the diameter ratio of the strand.

(25) More particularly, in the area A, in which the differential pressure is decreased, the flow path of the feed spacer can be increased by decreasing the angle a1 between the first and second sets 10 and 20 and increasing a diameter difference between the protruding portion W2 and the non-protruding portion W1. Accordingly, when raw water is introduced through the feed spacer, the feed spacer does not interrupt a flow of the raw water by the wide flow path, so that there can be an effect in that the differential pressure is decreased. The generation of the differential pressure is decreased, so that it is possible to provide the feed spacer, which is capable of mitigating the concentration polarization phenomenon of the feed spacer and improving efficiency of the reverse osmosis filter module.

(26) More particularly, in the area B, in which the recovery is increased, the flow path of the feed spacer can be decreased by increasing the angle a2 between the first and second sets 10 and 20 and decreasing a diameter difference between the protruding portion W2 and the non-protruding portion W1′, thereby increasing the amount of permeating water. That is, in the case where raw water is provided to the feed spacer with the same pressure, when the flow path of the feed spacer is decreased, the pressure is increased. Accordingly, there can be an effect in that the recovery is increased according to the increased pressure.

(27) In this case, the diameter of the non-protruding portion W1 of the area A, in which the differential pressure is decreased, can be different from the diameter of the non-protruding portion W1′ of the area B, in which the recovery is increased. That is, the diameter ratio of the area A, in which the differential pressure is decreased, and the area B, in which the recovery is increased, can be adjusted by the non-protruding portions W1 and W1′.

(28) Accordingly, the present invention is characterized in that a height of the feed spacer according to the present invention is the same in the area A, in which the differential pressure is decreased, and the area B, in which the recovery is increased.

(29) Reverse Osmosis Filter Module

(30) The reverse osmosis filter module is a constituent element of a membrane separation device, which serves to purify actually supplied water by using a reverse osmosis pressure principle. The reverse osmosis filter module can include a reverse osmosis membrane, a feed spacer, a tricot filtered water path, and a tube including an opening accommodating a permeating liquid according to a longitudinal direction. Further, the reverse osmosis filter module can further include one pair of telescoping preventing devices, but a detailed description of the telescoping preventing device will be omitted.

(31) One or more reverse osmosis membranes filter foreign materials included in water by using osmosis and serve as a flow path allowing purified water to effectively flow. The one or more reverse osmosis membranes are extended to an outside direction from the tube and are wound around a circumference of the tube.

(32) As the feed spacer, the feed spacer according to the present invention can be provided. More particularly, the feed spacer can be formed of first and second sets, in which a plurality of strands is positioned in parallel, and can be separated into one or more areas by an angle between the first and second sets and a difference in a diameter ratio of the strand between the first and second sets. The feed spacer according to the present invention is the same as the foregoing feed spacer, so that a detailed description thereof will be omitted.

(33) The feed spacer forms a passage, through which raw water is introduced from the outside, and serves to maintain a gap between one reverse osmosis membrane and another reverse osmosis membrane. To this end, the feed spacer is in contact with one or more reverse osmosis membranes at an upper side and a lower side, and is formed to be wound around the circumference of the tube similar to the one or more reverse osmosis membranes.

(34) Herein, a material of the feed spacer is not specially limited, but can include any one of polyethylene, polyvinyl chloride, polyester, and polypropylene.

(35) The tricot filtered water path has a structure of a general fabric form, and serves as a flow path making a space, through which the water purified through the reverse osmosis membrane 10 can flow out.

(36) The tube is positioned at a center of the reverse osmosis filter module for water treatment, and serves as a passage, through which the filtered water is introduced and discharged.

(37) To this end, voids (or openings) having a predetermined size can be formed at an external side of the tube so that the filtered water is introduced. In this case, it is preferred that the number of voids formed can be one or more so that the filtered water is more effectively introduced.

Comparative Example

(38) A feed spacer in the related art is formed in one mesh form, in which angles of the first and second sets, distances between the strands (distances between the cross points), a diameter difference of the strand are the same.

Example

(39) Example is the feed spacer according to the present invention, which is formed in two forms, specifically angles of the sets, distances between the strands (distances between the cross points), and a diameter difference of the strand are different from each other.

(40) TABLE-US-00001 TABLE 1 First stage Second stage Pa/μm 0.0144 0.0205

(41) TABLE-US-00002 TABLE 2 Comparative Example Example Pa/μm 0.123 0.105

(42) Table 1 represents a differential pressure (Pa/μm) for a unit length of each of the first stage and the second stage of the Example, and Table 2 represents a differential pressure (Pa/μm) for a unit length of each of the Comparative Example and the Example.

(43) First, in the Example, it can be seen that a differential pressure (Pa/μm) in the area A (the first stage), in which a differential pressure is decreased, is decreased by 70% compared to the area B (the second stage), in which a recovery is increased. Further, a differential pressure per unit length of the Comparative Example is 0.123 Pa/μm and a differential pressure per unit length of the Example is 0.105 Pa/μm, so that it can be seen that the differential pressure per unit length of the Example is decreased by 85% compared to the differential pressure per unit length of the Comparative Example.

(44) In the forgoing, the present invention has been described with reference to the exemplary embodiment of the present invention, but those skilled in the art can appreciate that the present invention can be variously corrected and changed within the range without departing from the spirit and the area of the present invention described in the appending claims.