JPH1199304A - Sand filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized sand filter which can effectively perform waste water treatment and also whose backwashing operation is easy with respect to sand filters in which suspended matter is removed by a filter medium bed packed with an amorphous filter medium such as sand, cokes, and anthracite. SOLUTION: In this device, a cylindrical body 8 having end face plates 9 at both the ends thereof is pivotally supported rotatably around the central axis in an untreated tank 1 containing suspension water W1 . The cylindrical body 8 is packed with an amorphous material such as sand leaving a space 10 in the upper part thereof, and in an outer peripheral wall 6, many holes each having such size that the amorphous filter medium cannot permeate through them are made. A water collecting pipe 19 is arranged on the axis line of the cylindrical body, embedded in the amorphous filter medium, and an inner peripheral wall 7 in which the many holes are provided leaving a constant clearance 18 from the water collecting pipe 19, is provided. To the water collecting pipe 19, a blower 21 for sending air on filter medium washing is connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method in which suspended water discharged from a factory or the like is put into a filter medium layer filled with an irregular filter medium such as sand, coke or anthracite, and the suspended water causes the filter medium layer to gravity move. The present invention relates to a sand filtration device which removes suspended matter by a combined effect of sedimentation, adsorption, and biological action while coming out, and in particular, sand capable of obtaining medium water which can be used for flush toilets and watering plants. The present invention relates to a filtration device.

[0002]

2. Description of the Related Art Sand filters are intended for wastewater having a low concentration of suspended matter, and are characterized by a high removal rate of suspended matter and good water quality after treatment. However, in the case of medium-concentration drainage, clogging is likely to occur, so the number of backwashing must be increased, and if a large amount of water is to be treated, a large-sized apparatus must be used.

[0003] Therefore, there has been proposed a filter device in which a filter material layer is formed in a cylindrical shape and is buried in suspension water contained in an untreated tank, and water is passed from the outside to the inside of the cylinder (for example, see, for example).
JP-A-5-49814). In this filtration device, end plates 9 and 9 are attached to both sides of a cylindrical drum 8 having an outer peripheral wall 6 made of a wire mesh, and the upper half of the cylindrical drum 8 is filled with filter sand while leaving a space 10. One end of a water collecting pipe buried in the center of the cylinder is bent into an L shape and extended to the axis of the cylindrical drum, and this extended end is connected to the filtered water pipe 31 located on the axis of the cylindrical drum.

[0004] This filtration device has the advantage that it is small and can secure a large filtration area. If clogging occurs during the continuation of filtration, the cylindrical drum is slowly rotated to wash (backwash) dirt adhering to the filtered sand. When the cylindrical drum is rotated slowly, the filtered sand moves up to the space 10 side together with the outer peripheral wall of the cylindrical drum, and then separates from the outer peripheral wall and falls, and collides with each other to separate dirt, and at the same time, the inner surface of the outer peripheral wall is filtered. It is rubbed and cleaned with sand. At this time, by pouring water into the water collecting pipe, the released dirt can be quickly discharged to the outside of the cylindrical drum.

[0005]

However, in the above-mentioned apparatus, only the lower half of the cylindrical drum is filled with sand, so that the water collecting pipe must be disposed with a downward bias. In order to drain the filtered water from the filtered water pipe located above the heart, a vertical portion must be provided at the end of the collecting pipe, which complicates the structure. In addition, there is a problem that sand in the center of the cylindrical drum is hardly agitated at the time of back washing, so that dirt attached to the filter material cannot be completely removed. There is a problem that can not be.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small-sized sand filtration device capable of efficiently performing wastewater treatment and easily performing a backwashing operation.

[0007]

Sand filtration apparatus SUMMARY OF THE INVENTION The first aspect, the tubular body 8 has a central axis having an end face plate 9, 9 at both ends in the untreated tank 1 for accommodating the suspended water W ₁ The cylindrical body 8 is filled with an irregular filter material such as sand, leaving a space 10 in the upper part thereof, and the outer peripheral wall 6 is large enough to prevent the irregular filter material from passing therethrough. And a plurality of through-holes are provided.
The water collecting pipe 19 is arranged on the axis of the cylindrical body, and the inner peripheral wall 7 is provided at a predetermined gap 18 from the water collecting pipe 19, and the irregular-shaped filter medium passes through the inner peripheral wall 7 A large number of through-holes of an impossible size are provided, and a blower 21 for sending air at the time of washing the filter medium is connected to the water collecting pipe 19.

According to a second aspect of the present invention, there is provided the sand filter according to the first aspect, wherein the water collecting pipe 19 is opened to the treated tank 2 containing the filtered water W ₂ , and a pump 25 is connected to the treated tank 2. Return pipe 2 connected to collection pipe 19 and untreated tank 1 through
7a and 27b are provided.

[0009]

According to the first aspect of the present invention, since the water collecting pipe 19 is arranged on the axis of the filtration drum 8, the installation structure of the filtration drum, piping work, and maintenance work are easy. Also, the inner peripheral wall 7
Is provided to form a donut shape, so that the filling amount of the filtering material can be reduced without reducing the filtration area and without increasing the flow velocity in the central portion. Therefore, the weight of the entire apparatus can be reduced, and the initial cost and running cost can be reduced.

Further, since the gap 18 is formed between the inner peripheral wall 7 and the water collecting pipe 19, air bubbles generated from the water collecting pipe 19 can be evenly dispersed. In addition, pro water 2
Since 1 is connected, air bubbles radiated from the water collecting pipe agitate the upper filter medium to promote the removal of dirt, thereby shortening the backwashing time.

[0011] According to a second aspect of the invention, which return water pipe 27a to the water collecting tube 19 is connected, the filtered water W ₂ of the treated vessel through the pump 28 during backwashing can be released from the water collecting pipe 19 The dirt separated from the filter material can be discharged to the outside of the filter drum. Further, the filtered water W ₂ by opening the return water pipe 27b after backwashing step and treated tank 2 untreated vessel 1
And can be cycled between.

[0012]

FIG. 1 and FIG. 2 show an embodiment of the present invention. Sand filtration apparatus of this embodiment, the untreated tank 1 containing water suspension W ₁ factory waste water, filtered water W ₂
And a treated tank 2 for storing the same. A raw water pipe 3 is opened above the untreated tank 1, and a sewage discharge pipe 5 having a first on-off valve 4 is connected to a bottom surface of the untreated tank 1. A filtration drum 8 having an outer peripheral wall 6 and an inner peripheral wall 7 made of wire mesh is submerged in the untreated tank 1, and the filtration drum untreats left and right shafts 11, 11 protruding from both side end plates 9, 9. It is rotatably supported by bearings 13, 13 provided on opposed side walls 12, 12 of the tank 1. Sand, coke, sand, coke, and the like
An amorphous filter material such as anthracite is filled except for the space 10. A driven sprocket 14 is fixed to the shaft 11 on the right side of the drawing, and the driven sprocket 14 is connected to a driving sprocket 16 of a motor 15 fixed above the untreated tank 1 by a chain 17. A water collecting pipe 19 is provided on the axis of the filtration drum 8 with a circumferential wall 7 and a gap 18 therebetween, and the right end (drainage side) of the water collecting pipe 19 passes through the right shaft 11 to form the untreated tank 2. It projects outward and is connected to the filtered water pipe 31. The outlet of the filtered water pipe 31 opens above the treated tank 2.

A third on-off valve 32 is provided at the outlet side of the filtered water pipe 31.
The air pipe 22 of the blower 21 is connected to the collection pipe side of the filtered water pipe via a second on-off valve 23. A drain pipe 24 for discharging overflow is provided above the treated tank 2, and a water suction pipe 26 of a return pump 25 is opened below. The return pipe 27 of the return pump 25 is branched into two, while the return pipe 27a is connected to the filtered water pipe 31 through the fourth on-off valve 28.
The other 27b is connected to the untreated tank 1 via a fifth on-off valve 29.

Next, the operation of the sand filter of this embodiment will be described. Usually supplied to the water suspension W ₁ is unprocessed tank 1 from the raw water pipe 3, aqueous suspension flows from the outside to the inside of the filtration drum 8, the suspension is adsorbed and removed by filtering material layer. The filtered water W ₂ from which the suspended matter has been removed enters the gap 18 between the inner peripheral wall 7 and the collecting pipe 19, flows out to the filtered water pipe 31 through the collecting pipe 19, and is discharged to the treated tank 2. Filtered water W _{2 in the} treated tank
Overflows and is discharged from the overflow pipe 24. During this filtration operation, the filtration drum 8 is stopped.

[0015] After filtration media layer is clogged the water of the water suspension W ₁ is been increased, which enters the backwash step to stop the inflow of aqueous suspension is detected by a sensor or the like. Close the third on-off valve 32,
While driving the motor 15 to rotate the filtration drum 8,
The compressed air is sent from the blower 21 to the filtered water pipe 31. The compressed air passes through the filtration water pipe 31 and passes from the collection pipe 19 to the gap 18.
As bubbles in the filtered water. The air bubbles are uniformly radiated to the filter medium layer through the through holes in the inner peripheral wall 7. The rotation of the filtration drum 8 causes the filtration material to move upward in the space 10 along the outer peripheral wall 6, to collapse near the top, and to rub against each other to be washed. At this time, since air bubbles are diverged from the water collecting pipe in the filter medium layer, the inner filter medium and the outer filter medium move, and the filter medium is washed evenly. Then the fourth on-off valve 28
Opening the for a predetermined time backflow filtered water W ₂ by the pump 25. Stripping dirt from the filtering material is returned to the aqueous suspension W ₁ untreated vessel 1 from the outer peripheral wall 6, a high concentration of dirt wastewater. The first opening valve 4 is opened to discharge sewage.

Next, the suspension water is put into the untreated tank 1 from the raw water pipe 3 and the suspension is filled up and stopped. Third and fifth on-off valves 32, 2
9 by opening by circulating filtered water W ₂ is washed for a predetermined time filtering material layer. After a lapse of time, the pump is stopped, and the fifth on-off valve 29
To return to the normal filtration process.

[Brief description of the drawings]

FIG. 1 is a schematic view of a sand filtration device of the present invention.

FIG. 2 is a sectional perspective view of a main part of the sand filtration device.

FIG. 3 is a perspective view of a conventional sand filtration device.

[Explanation of symbols]

1 Untreated tank 2 Treated tank 6 Outer wall 7 Inner wall 8 Filtration drum 10 Void 18 Gap 19 Water collecting pipe 21 Blower 25 Return pump W ₁ Suspended water W ₂ Filtrated water

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 33/80 B01D 33/34

Claims (2)

[Claims] A cylindrical body (8) having end plates (9, 9) at both ends in an untreated tank ( ₁ ) for storing suspended water (W ₁ ) is rotatably supported around its central axis. The cylindrical body (8) is filled with irregular shaped filter material such as sand, leaving a space (10) at the top,
The outer peripheral wall (6) is provided with a large number of through-holes through which the irregular-shaped filter medium cannot pass.In the sand filtration device in which the water-collecting pipe (19) is disposed by being buried in the irregular-shaped filter medium, (1
9) is arranged on the axis of the cylindrical body, and an inner peripheral wall (7) is provided with a certain gap (18) from the water collecting pipe (19), and the amorphous filter cannot pass through the inner peripheral wall (7). A large number of through holes are provided,
A sand filter, characterized in that a blower (21) for sending air at the time of washing a filter medium is connected to the water collecting pipe (19). 2. A water collecting pipe (19) is open to a treated tank (2) for containing filtered water (W ₂ ), and the treated water collecting pipe (19) is connected to the treated tank (2) via a pump (25). ) And return pipe connected to the untreated tank (1)
The sand filtering device according to claim 1, wherein (27a, 27b) is provided.