JP2012050944A - Filter and strainer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter to which a strainer can be easily and quickly mounted and which enables easy exchange of a filter layer by eliminating support gravel and forming the filter layer with sand having a small particle size, and a strainer.SOLUTION: The strainer 6 is disposed on a filter bed 51 dividing a filter tank 2 into an upper filter chamber 41 and a lower filter chamber 42. The strainer 6 is composed of a strainer body 61 including a plurality of slits 70 through which water passes, and a receiving part 62 inserted into a through-hole 52 formed in the filter bed 51, from above. The width L1 of the slit 70 is set smaller than the particle size of filter media 11. When a leg 63 of the strainer body 61 is inserted into the receiving part 62, the diameter of the receiving part 62 is expanded to be fixed to the filter bed 51. The strainer body 61 is provided with an engaging part 64 engaged with a part to be engaged 72 provided in the receiving part 62.

Description

  The present invention relates to a filtration apparatus for obtaining treated water by filtering raw water by passing it through a filter medium layer, and a strainer used in the filtration apparatus.

  Conventionally, in a filtration apparatus that filters raw water such as seawater, the inside of a filtration tank is partitioned into an upper filtration chamber and a lower filtration chamber by a filter medium layer. The filter media layer is composed of two types of filter media having different particle diameters (diameters). Those having a large particle size are laid on the filter bed as supporting gravel. A filter bed is further provided on the support gravel, and sand having a small particle diameter is laid on the upper filter bed.

  A plurality of strainers are disposed on the lower filter bed on which the supporting gravel is laid. That is, a plurality of openings are formed in the filter bed, and a strainer is inserted into each opening from above. A male thread portion is provided at a portion of the strainer that projects downward from the filter bed. The strainer is fixed to the filter bed by screwing a nut into the male thread portion from below the filter bed (see, for example, Patent Document 1).

  And at the time of the normal filtration which filters raw | natural water with the said filtration apparatus, raw | natural water is introduce | transduced into an upper filtration chamber. The raw water introduced into the upper filtration chamber passes through the filter medium layer downward, passes through the strainer and becomes treated water and flows into the lower filtration chamber. And the filtered treated water is discharged | emitted from the inside of a filtration tank.

  When such a filtering device is used for a long period of time, the filter medium is clogged, and efficient filtration cannot be performed. For this reason, the operation | work which removes the pollutant adhering to a filter medium, what is called a back washing operation (back washing) is performed. In such backwashing, the treated water in the lower filtration chamber is introduced into the upper filtration chamber in the opposite direction to the filtration to wash the filter medium, and the washed water is discharged from the filtration tank.

JP 2004-160432 A

  When attaching a plurality of strainers to a filter bed, the filtration device described in Patent Document 1 must be fastened and fixed by operating a nut from below the filter bed. For this reason, an operator who inserts the strainer into the opening of the filter bed from above the filter bed and an operator who operates the nut from below the filter bed are required. Further, the operation of operating the nut from the lower side of the filter bed is difficult to secure a sufficient work space, and the strainer installation work is troublesome.

  Moreover, the supporting gravel and sand used as a filter medium layer may be replaced. Since sand has a small particle size, it can be removed by a worker using a tool such as a scoop. However, since support gravel has a large particle size, it cannot be scooped with such a tool. At present, it is removed by hand.

  Therefore, in view of the above problems, the present invention allows the strainer to be easily and quickly attached to the filter bed, and replaces the filter medium by constructing a filter medium layer made of sand having a small particle diameter without supporting gravel. An object of the present invention is to provide a filtration device and a strainer that can be easily and quickly performed.

  The present invention has been made in order to solve the above-mentioned problems, a filtration tank having a filtration chamber, a filter bed that divides the filtration chamber into an upper filtration chamber on the upper side and a lower filtration chamber on the lower side, Water having a filter medium layer formed of a filter medium provided on the upper surface of the filter bed and a strainer disposed on the filter bed, the raw water introduced into the upper filtration chamber being filtered by passing through the filter medium Is introduced into the lower filtration chamber through the strainer and discharged from the filtration tank, and the water in the lower filtration chamber is guided to the upper filtration chamber through the strainer opposite to the time of the filtration, and the filter medium is washed. In the filtration device for discharging the water from the filtration tank, the strainer is a cylindrical shape that is inserted from above into a strainer body portion in which a plurality of slits through which water passes is formed, and a through hole formed in the filter bed. The receiving part is composed of The width dimension of the slit is set to be smaller than the particle size of the filter medium, and the strainer main body portion has a leg portion inserted from above into the receiving portion, and the receiving portion is expanded when the leg portion is inserted. The diameter is fixed to the filter bed, and the strainer body is provided with an engaging portion that engages with the engaged portion provided in the receiving portion.

  In the filtration apparatus of the present invention, when the strainer is fixed to the filter bed, first, the receiving part is inserted into the through hole formed in the filter bed from above. Next, the leg portion of the strainer main body portion is inserted into the receiving portion from above, so that the diameter of the receiving portion is increased when the leg portion is inserted and is supported on the filter bed. Furthermore, by engaging the engaging part of the strainer body part with the engaged part of the receiving part, the strainer body part can be fixed to the receiving part fixed to the filter bed. As described above, the operation of fixing the strainer to the filter bed can be performed from above the filter bed.

  Further, in the strainer in the filtration device of the present invention, a plurality of slits through which water passes is formed in the strainer main body, and the width dimension of the slit is set smaller than the particle size of the filter medium. Does not enter the strainer from the slit, and a filter medium having a small particle size can be laid on the upper surface of the filter medium, and it is not necessary to interpose a supporting gravel between the filter medium and the filter bed.

  In the filtering device, the receiving portion is formed with a notch, and the inner peripheral surface of the receiving portion is formed into a tapered surface whose diameter gradually decreases downward, and the leg portion of the strainer main body portion. However, it is preferable that the diameter of the receiving portion is increased by opening the notch.

  In the filtering device, it is preferable that the engaging portion of the strainer main body portion is a male screw portion, and the engaged portion of the receiving portion is a female screw portion into which the male screw portion is screwed.

  The present invention is a strainer disposed on a filter bed that supports a filter medium layer in a filtration tank, and a strainer main body portion having a plurality of slits through which water passes, and a through hole formed in the filter bed. The slit is set to be smaller than the particle size of the filter medium, and the strainer body is inserted into the receiving portion from above. It has a leg part, and when the leg part is inserted, the receiving part is expanded in diameter and fixed to the filter bed, and the strainer body part is provided with an engaging part that engages with the engaged part provided in the receiving part. There is in being.

  In the present invention, when the strainer is fixed to the filter bed, the operation of fixing the receiving portion to the filter bed and the operation of fixing the strainer main body portion to the receiving portion fixed to the filter bed are performed from above the filter bed. Can be done. As a result, unlike the conventional case, it is not necessary to operate the nut from below the filter bed, and the work of fixing the strainer to the filter bed can be performed easily and quickly.

  Further, the strainer is formed with a plurality of slits through which water passes in the strainer body, and the width dimension of the slit is set smaller than the particle size of the filter medium, so that the particle size is small on the upper surface of the filter medium. Even if the filter medium is laid, the filter medium does not enter the strainer from the slit, and it is not necessary to interpose support gravel between the filter medium and the filter bed. As a result, when the filter medium layer is replaced, there is no need to remove the supporting gravel, and it is only necessary to replace the filter medium having a small particle diameter, which is advantageous in that the filter medium layer can be easily replaced.

It is sectional drawing which shows the outline of the filtration apparatus which concerns on one Embodiment of this invention. It is a top view of the filtration apparatus. It is a top view which shows the filter medium installation means used for the filtration apparatus. The strainer main-body part of the strainer which concerns on one Embodiment of this invention is shown, (a) is a half cut sectional view, (b) is a principal part front view which shows a slit. The receiving part of the strainer is shown, (a) is a sectional view, (b) is a bottom view showing a part. The same strainer is shown, (a) is a cross-sectional view immediately before fitting the strainer body part to the receiving part, (b) is a cross-sectional view of the state in which the strainer body part is fitted to the receiving part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 6 show an embodiment of the present invention.

  FIG. 1 is a cross-sectional view showing an outline of the filtration device according to the present embodiment, and FIG. 2 is a plan view of the filtration device. In FIG. 1, the filtration device 1 includes a filtration tank 2 having a vertical tank shape as a whole. The filtration tank 2 is partitioned into a water storage chamber 3 on the upper side and a filtration chamber 4 on the lower side by a partition wall 21 provided at an intermediate portion in the vertical direction inside the filtration tank 2.

  The partition wall 21 has a spherical shape with its central portion swelled upward, and has such a strength that it can sufficiently withstand the water pressure in the water storage chamber 3 even when the wall thickness is reduced. It is An air hole 27 communicating with the water storage chamber 3 is provided at the top of the filtration tank 2 so that the water storage chamber 3 is open to the atmosphere.

  The filtration chamber 4 is partitioned into an upper filtration chamber 41 on the upper side and a lower filtration chamber 42 on the lower side by the filter medium installation means 5 having water permeability. As shown in FIG. 3, the filter medium installation means 5 includes a disk-shaped filter bed 51 and a plurality of strainers 6 arranged radially on the filter bed 51.

  On the upper surface of the filter medium installation means 5, for example, sand (filter medium) having a particle diameter of 0.5 mm is laid with a constant lamination thickness, and this sand layer constitutes the filter medium layer 10. The filter medium layer 10 is composed of sand having a particle size of 0.5 mm in a single layer, and unlike the prior art, no supporting gravel is laid.

  One end of the raw water supply pipe 22 communicates with the upper filtration chamber 41 through the wall surface of the filtration tank 2. The raw water supply pipe 22 includes a raw water electric on-off valve 23 as a raw water on-off valve. By opening the raw water electric on-off valve 23, raw water is supplied into the upper filtration chamber 41 via the raw water supply pipe 22. Is done. The raw water is pumped through the raw water supply pipe 22 by the raw water supply pump 25.

  In the filtration tank 2, a plurality of water collecting pipes 8 having one end opened toward the lower filtration chamber 42 and the other end opened toward the water storage chamber 3 include a partition wall 21, a filter medium installation means 5, and a filter medium layer. 10 is disposed vertically.

  A water intake pipe 30 is provided through the side wall at the bottom of the filtration tank 2 so as to communicate the inside of the lower filtration chamber 42 and the outside of the filtration tank 2. The water intake pipe 30 is connected with an electric on-off valve 31 for treated water as a treated water on-off valve.

  A backwash water drain pipe 9 is provided in the vertical direction substantially at the center of the filtration chamber 4. The backwash water drain pipe 9 has an upper portion that penetrates the partition wall 21 and a lower portion that is bent in an L shape in the horizontal direction and protrudes to the side of the filtration tank 2. And the backwashing electric on-off valve 91 as a backwash on-off valve is attached to the protruding front end outlet. In addition, a drainage inlet 92 that opens in the upper filtration chamber 41 is opened above the backwash water drain pipe 9.

  As shown in FIGS. 4 to 6, the strainer 6 is disposed above the strainer main body 61 and a plurality of through holes 52 provided radially on the filter bed 51 in order to connect the strainer main body 61 to the filter bed 51. It is comprised from the receiving part 62 inserted from.

  As shown in FIG. 4A, the strainer body 61 includes a cylindrical leg 63 and a hollow head 65 that is connected to the upper opening end of the leg 63. That is, the strainer main body 61 is a hollow member in which the lower open end of the cylindrical leg 63 is opened.

  The diameter D1 of the head 65 is bulged and formed so as to be larger than the diameter D2 of the leg 63. The head 65 has a cylindrical side surface 66 and a ceiling surface 67 that closes the upper end of the side surface 66. And. A plurality of slits 70 are formed around the side surface 66 at predetermined intervals so as to communicate with the inside and outside of the head 65. The width dimension (length in the circumferential direction of the head 65) L1 of the slit 70 is set smaller than the particle size of the filter medium 11, as shown in FIG. For example, when the particle diameter of the filter medium 11 is 0.5 mm, the width dimension L1 of the slit 70 is set to 0.4 mm. The slit 70 is formed continuously over substantially the entire length of the side surface 66 in the vertical direction. In addition, the slit 70 can be formed intermittently (discontinuously) in addition to being continuously provided in the vertical direction of the side surface 66.

  An annular portion 69 that closes the lower surface opening of the head portion 65 is provided on the upper surface of the leg portion 63, and the outer peripheral surface of the annular portion 69 and the lower peripheral surface of the head portion 65 are ultrasonically bonded, for example. ing. Further, a male screw portion 64 as an engaging portion is provided at the upper portion of the leg portion 63 and in the vicinity of the annular portion 69.

  As shown in FIGS. 5A and 5B, the receiving portion 62 includes a cylindrical receiving portion main body 68 whose upper and lower surfaces are open, and a flange portion 69 provided on the upper portion of the receiving portion main body 68. The outer diameter D3 of the receiving portion main body 68 and the diameters of the plurality of through holes 52 provided radially in the filter bed 51 are set to be substantially the same diameter so that the receiving portion main body 68 can be fitted into the through holes 52. It has become.

  A female screw portion 72 as an engaged portion to which the male screw portion 64 is screwed is provided on the inner surface 68a of the receiving portion main body 68 and the portion where the flange portion 69 is located. In addition, the inner surface 68 a of the receiving portion main body 68 and a portion below the female screw portion 72 are tapered so that the diameter decreases toward the lower opening end of the receiving portion main body 68. Furthermore, a notch 71 that opens on the lower surface of the receiving portion main body 68 is formed in the tapered portion of the receiving portion main body 68.

  Next, the case where the strainer 6 having the above configuration is fixed to the filter bed 51 will be described. First, the receiving portion main body 68 of the receiving portion 62 is inserted into the through hole 52 of the filter bed 51 and pushed in from above until the flange portion 69 comes into surface contact with the upper surface of the filter bed 51. At this time, since the flange portion 69 engages with the upper surface of the filter bed 51, it acts as a stopper, and the receiving portion 62 is supported by the filter bed 51 (see FIG. 6A).

  Next, the leg portion 63 of the strainer main body 61 is inserted into the receiving portion main body 68 of the receiving portion 62 supported by the filter bed 51. The outer diameter D2 of the leg portion 63 is set to be the same as the inner diameter of the upper opening end of the receiving portion main body 68, but the inner diameter 68a of the receiving portion main body 68 has a smaller diameter toward the lower opening end. Tapered. From this, as the insertion of the leg portion 63 becomes deeper, the leg portion 63 slides along the inner surface 68 a of the receiving portion main body 68. As described above, the leg 63 slides along the inner surface 68a which is the tapered surface of the receiving part main body 68, so that the notch 71 provided in the receiving part main body 68 is expanded. The part main body 68 is lowered while expanding its diameter.

  Further, when the male screw portion 64 of the leg portion 63 reaches the female screw portion 72 of the receiving portion 62, the strainer main body portion 61 is rotated. Since the outer diameter D3 of the receiving portion main body 68 is larger than the diameter of the through hole 52 as described above, the receiving portion main body 68 is pressed against the peripheral surface of the through hole 52 of the filter bed 51. For this reason, the receiving part 62 maintains a fixed state without being rotated by the rotation of the strainer body part 61.

  Therefore, the male threaded portion 64 of the rotating strainer body 61 can be screwed into the female threaded portion 72 of the receiving portion 62 that is fixed. Accordingly, the strainer main body 61 can be fastened and fixed to the receiving portion 62, and the receiving main body 68 has a tapered shape in which the diameter gradually expands downward, so that the strainer main body 61 does not come out of the filter bed 51 unnecessarily. As a result, the operator can easily and quickly fix each strainer 6 from above the filter bed 51 without rattling the filter bed 51 (see FIG. 6B). In the present embodiment, one or more workers may fix each strainer 6 from above the filter bed 51, but unlike the conventional case, the operation of operating the nut from below the filter bed 51. A person becomes unnecessary. Moreover, the operation | work which fixes each strainer 6 can be normally performed by the upper filtration chamber 41 side with a large space.

  A case where raw water such as seawater is filtered using the filtration device having the above configuration will be described. Note that. In FIG. 1, the flow directions of raw water and treated water are indicated by solid lines.

  First, the raw water electric open / close valve 23 is opened, the treated water electric open / close valve 31 and the backwash electric open / close valve 91 are closed, and the raw water supply pump 25 passes through the raw water supply pipe 22 to the inside of the upper filtration chamber 41. To supply raw water. The raw water supplied into the upper filtration chamber 41 is filtered by passing through the filter medium layer 10 from the upper part toward the lower part.

  The treated water filtered by the filter medium layer 10 passes through the strainer 6 and flows into the lower filtration chamber 42. Specifically, the treated water enters the head 65 through a slit 70 formed in the head 65 of the strainer 6. The filter medium 11 of the filter medium layer 10 has a particle size larger than the width dimension L1 of the slit 70, so that the filter medium 11 does not enter the head 65 through the slit 70. Moreover, the slit 70 is formed continuously over substantially the entire length of the head 65 of the strainer 6 in the vertical direction. Accordingly, the slit 70 has a sufficient opening area for the treated water to pass through because the slit 70 has a width dimension that does not allow the filter medium 11 to pass therethrough, and is opened in a long shape in the vertical direction.

  The treated water that has entered the head 65 flows downward in the legs 63 and flows into the lower filtration chamber 42. The treated water flowing into the lower filtration chamber 42 enters the water collection pipe 8 due to the pressure of the raw water supply pump 25, rises up the water collection pipe 8, flows out into the water storage chamber 3, and is stored in the water storage chamber 3.

  After storing a predetermined amount of treated water in the water storage chamber 3, the treated water electric on-off valve 31 is opened. By opening this electrically-operated on-off valve 31 for treated water, treated water stored in the lower filtration chamber 42 is sent to the irrigation section via the intake pipe 30. The amount of raw water supplied into the upper filtration chamber 41 via the raw water supply pipe 22 is controlled so that a predetermined amount of treated water can be stored in the water storage chamber 3. Such control of the raw water amount can be performed by controlling the raw water supply pump 25.

  Next, the case where the filter medium 11 is back-washed due to clogging in the filter medium layer 10 in the filtration device 1 will be described. Note that. In FIG. 1, the flow direction of treated water is indicated by a broken line.

  The filter medium layer 10 is backwashed by closing the raw water electric open / close valve 23 and the treated water electric open / close valve 31 and opening the backwash electric open / close valve 91. By opening the backwashing electric on-off valve 91, the filtration chamber 4 side is released to the atmosphere side through the backwashing drain pipe 9. The treated water stored in the water storage chamber 3 flows into the water collecting pipe 8 and flows into the lower filtration chamber 42 by its own weight.

  The treated water that has flowed into the lower filtration chamber 42 flows into the receiving member 62 of the strainer 6 in the opposite direction, flows upward, and flows out from the slit 70 of the strainer main body 61. At this time, the slit 70 functions as a nozzle, and the treated water is discharged radially from the strainer main body 61, so that the treated water diffuses and rises uniformly over the entire surface of the filter medium layer 10.

  Thus, the treated water flowing out from the slit 70 flows to the upper filtration chamber 41 through the filter medium layer 10, and removes the clogged suspended matters when passing through the filter medium layer 10. The backwash water mixed with the removed underwater suspended matter is discharged through the backwash water drain pipe 9 from the drain inlet 92 of the backwash water drain pipe 9. Thereby, the filter medium layer 10 can be back-washed.

  As described above, in the filtering device 1 according to the present embodiment, the filter medium 11 made of sand having a particle diameter of 0.5 mm is laid on the upper surface of the filter medium installation means 5 with a constant lamination thickness. The layer becomes the filter medium layer 10. In the present embodiment, since no supporting gravel is interposed between the filter medium 11 and the filter medium setting means 5, when replacing the filter medium layer 10, it is not necessary to remove the support gravel. There is an advantage that the replacement work of the filter medium layer 10 is facilitated only by replacement.

  The present invention is not limited to the embodiment described above. For example, although the thing provided with the water storage chamber 3 which stores treated water as the filtration tank 2 was illustrated, the filtration tank 2 is not provided with the water storage chamber 3, but the tank which stores backwash water is provided via piping. It may be configured to be connected.

DESCRIPTION OF SYMBOLS 1 Filtration apparatus 2 Filtration tank 3 Water storage chamber 4 Filtration chamber 5 Filter material installation means 6 Strainer 10 Filter material layer 23 Raw water electric on-off valve 25 Raw water supply pump 31 Raw water electric on-off valve 41 Upper filtration chamber 42 Lower filtration chamber 51 Filter bed 52 Through Hole 61 Strainer body 62 Receiving part 63 Leg 64 Male thread (engaging part)
65 Head 70 Slit 71 Notch 72 Female thread (engaged part)
91 Backwash electric on-off valve L1 Slit width

Claims (4)

A filtration tank having a filtration chamber;
A filter bed that divides the filtration chamber into an upper filtration chamber on the upper side and a lower filtration chamber on the lower side;
A filter medium layer composed of a filter medium provided on the upper surface of the filter bed;
A strainer disposed on the filter bed,
Water filtered through the raw water introduced into the upper filtration chamber through the filter medium is introduced into the lower filtration chamber via a strainer and discharged from the filtration tank,
In the filtration device for guiding the water in the lower filtration chamber to the upper filtration chamber through the strainer opposite to the time of filtration, washing the filter medium, and discharging the washed water from the filtration tank,
The strainer is composed of a strainer main body portion formed with a plurality of slits through which water passes, and a cylindrical receiving portion inserted from above into a through hole formed in the filter bed,
The width dimension of the slit is set smaller than the particle size of the filter medium,
The strainer main body has a leg portion inserted into the receiving portion from above, and when the leg portion is inserted, the receiving portion is expanded in diameter and fixed to the filter bed. The strainer main body portion is provided in the receiving portion. A filtering device comprising an engaging portion that engages with the engaged portion.   The filtration device according to claim 1, wherein the receiving portion is formed with a notch, and an inner peripheral surface of the receiving portion is formed into a tapered surface whose diameter gradually decreases downward, A filtration device, wherein the leg portion of the strainer main body portion is configured to expand the diameter of the receiving portion by opening the notch.   2. The filtration device according to claim 1, wherein the engaging portion of the strainer main body portion is a male screw portion, and the engaged portion of the receiving portion is a female screw portion into which the male screw portion is screwed. A filtration device characterized by the above. A strainer disposed on a filter bed for supporting a filter medium layer in a filtration tank,
A strainer body part in which a plurality of slits through which water passes is formed, and a cylindrical receiving part inserted from above into a through hole formed in the filter bed,
The width dimension of the slit is set smaller than the particle size of the filter medium,
The strainer main body has a leg portion inserted into the receiving portion from above, and when the leg portion is inserted, the receiving portion is expanded in diameter and fixed to the filter bed. The strainer main body portion is provided in the receiving portion. The strainer is provided with an engaging portion that engages with the engaged portion.

Images