JPH11169615A - Screw drum type filtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart the compression assisting function of treated raw water into the inlet chamber of a screw drum filtering device. SOLUTION: A filter cylinder 2 which consists of alternately superposed arrangements of annular stationary plates 10 and annular moving plates 11 which have the opening diameter slightly larger than the opening diameter of these stationary plates and oscillate at the amplitude meeting the bore difference thereof within the substantial range within a drum 1 and delineated with a stationary cylindrical space 12 by the opening array of the stationary plates is installed. A screw 5 penetrating this cylindrical space is extended up to the inlet chamber and is provided with mechanisms 15, 16 for oscillating the moving plates by rotation of this screw. The one end side of the drum is formed as the inlet chamber of the treated raw water communicating with a drum inlet hole 6a and the other end side is formed as an outlet chamber 7 of cake. Many through-holes 8 are disposed on the peripheral surface exclusive of the outlet chamber of the drum. An inlet screen plate 25 having many small hole 24 is arranged within the inlet chamber in such a manner that its curved base encloses the drum inlet hole as a whole by contact with a vane of the screw.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw drum type filtration device for filtering treated raw water containing sludge and other suspended matter to separate the filtrate into a filtrate and a dewatered cake.

[0002]

2. Description of the Related Art As a conventional screw drum type filtration device, for example, Japanese Patent Publication No. 63-36464 (Patent No. 152)
No. 0106) There is a screw-through filter tube installation system as described in the gazette. This type of filtration device
In a substantial area excluding both ends in the drum, a filtration cylinder for filtering the treated raw water in the radial direction from the inside of the cylinder to the outside of the cylinder is provided, and a large number of through holes are provided on the drum peripheral surface in the substantial area. In addition, a screw penetrating the filter tube is disposed over the entire length of the drum, and both ends in the drum are used as an inlet chamber for treated raw water and an outlet chamber for a dewatered cake. The filtration passage in the filter tube is formed by a minute gap between the plates in an alternate arrangement of the annular fixed plate and the annular movable plate that constitute the tube.

In the above construction, the inlet chamber guides the raw water from the drum inlet to the filter tube, and the outlet chamber serves as a buffer space for guiding the cake pressed and dewatered by the screw to the drum outlet. Although a volume is required, it is desired that these volumes be positively utilized for squeezing and dehydrating the phase to be treated. In this regard, Tokiko Sho 63
No. 65365 (Patent No. 1520107) discloses that
By the valve body fitted to the screw shaft in the outlet chamber,
A discharge control valve is provided to limit the cake discharged into the outlet chamber from the other end of the filter tube, and a low-concentration or insufficiently dewatered processed material is discharged as it is at the initial stage of introduction of the treated raw water into the filter tube. A configuration is described in which the discharge control valve is opened to start discharging the cake when the filtration proceeds and the pressure of the processed product (cake) increases due to the progress of filtration.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a screw drum filtration device capable of assisting the compression and dewatering of treated raw water even in an inlet chamber.

[0005]

In order to achieve the above object, the screw drum filtration device of the present invention comprises: a) a large number of annular fixed plates and an opening of the fixed plates in a substantial area excluding both ends in the drum. With a large number of annular movable plates having an opening diameter slightly larger than the diameter and capable of swinging at an amplitude corresponding to the diameter difference, an alternate superimposed arrangement in which fine gaps for filtration are provided, and the fixed plate Installing a filter tube defining a fixed cylindrical space by the row of openings; b) disposing a screw penetrating through the cylindrical space of the filter tube over substantially the entire length of the drum, and rotating the screw. A mechanism for oscillating the movable plate; c) an inlet chamber for treated raw water that communicates with a drum inlet hole between one end of the drum and one end of the filter tube opposite thereto. A space between the other end of the drum and the other end of the filter tube opposite thereto is an outlet chamber for the processed cake which communicates with the outlet hole of the drum. A hole is disposed to serve as a drain port. D) In the inlet chamber, a bottom surface having a substantially semicircular curved shape is in sliding contact with the blades of the screw, and has a plurality of small holes arranged so as to entirely surround the drum inlet hole. It is provided with an entrance screen plate having a letter-shaped or horseshoe-shaped cross section.

According to the above construction, the raw water introduced from the inlet of the drum is squeezed from a number of small holes of the inlet screen plate by the introduction pressure and the squeezing effect of the rotation of the screw, and the water is discharged from the screen plate (drum). (The inner wall side), and this drainage is discharged from the through-hole on the drum peripheral surface that is also present on the entrance chamber side, and the filter cylinder is supplied with treated raw water excluding this drainage, and the entire screw drum Can be improved in filtration or squeezing / dewatering effect.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a screw drum filtration device according to a preferred embodiment of the present invention will be described with reference to the drawings.

In FIG. 1 showing a basic embodiment, 1 is a drum, 2 is a filter tube which is installed in the drum 1 and is formed between both end plates 3 and 4, and 5 is inserted through the filter tube 2 and the drum 1
The screw 6, which is arranged over the entire length of the drum, is formed between the right end plate 3 and the right end of the drum 1 in the figure, and the drum inlet hole 6a
Is an outlet chamber formed between the left end plate 4 and the left end of the drum 1 and communicating with the drum outlet hole 7a. A large number of through holes 8 are formed in the peripheral surface of the drum except for the area of the outlet chamber 7 and the left end plate 4.

The filter tube 2 is provided between both end plates 3 and 4.
For example, a large number of annular fixed plates 10 fixed by four support rods 9 and a large number of annular movable plates 11 having opening diameters slightly larger than the opening diameters of the fixed plates.
The movable plate 11 can swing at an amplitude corresponding to the difference in diameter from the fixed plate 10 by a cam mechanism described later. In this case, a cylindrical space having a fixed inner peripheral surface 12 is defined by the row of openings of all the fixed plates 10, and the movable plate 11 does not narrow the inner peripheral surface 12 due to its swing. Therefore, the outer edge of the blade 13 of the screw 5 is fitted to the inner peripheral surface 12 and can rotate continuously.

Both ends of the shaft of the screw 5 are supported by bearings formed at both ends of the drum 1. The shaft end protruding from the bearing on the outlet chamber 7 side (left side in FIG. 1) is driven to rotate via gears and the like. The gear train 14 is interlocked with the rotating shaft 15. The rotating shaft 15 extends from the left end of the drum 1 in FIG. 1 to the right end plate 3 of the filter tube 2 at the lower portion of the horizontally arranged drum 1, and has a cam key 16 that extends in the axial direction within the range of the filter tube 2, thereby forming the movable plate 11. Can be rocked. This movable plate 1
1 can be better understood with reference to FIG. 2 drawn along the line AA of FIG.

As is apparent from FIG. 2, the fixed plate 10 has a complete annular shape having an outer peripheral surface connected to the inner peripheral surface of the drum 1 and an opening coplanar with the above-mentioned cylindrical inner peripheral surface 12. However, the movable plate 11 is composed of four support rods 9 of the filter cylinder 2 and a small disk penetrated and supported by the support rods 9, and has an outer diameter that fits inside the arrangement of the spacers 17,
Upper and lower projecting edges 19 and 20 are connected to an opening of the fixing plate 10, that is, an annular main body having an opening 18 having a diameter slightly larger than the cylindrical inner peripheral surface 12, and a fulcrum bar 21 is loosely fitted to the upper projecting edge 19. In addition, small holes 22 and 23 are formed in the lower overhanging edge 20 so that the rotary shaft 15 described above is fitted thereto. The fulcrum rod 21 is attached to the rotation shaft 15
Is erected between the end plates 3 and 4 so as to occupy an axially symmetric position.

The spacer 17 has a thickness for setting the distance between the fixed plates 10 and 10 as shown in FIG. 3 drawn along the line BB in FIG. By having a slightly larger thickness, a fine filtration gap is formed between the plates 10, 11;
Thus, a filter tube 2 (FIG. 1) composed of an array of a number of plates 10 and 11 is completed.

FIG. 4A shows a sectional structure of the inlet chamber 6 located on the upstream side of the filter tube 2. As is clear from this sectional view, an inlet screen plate 25 having a U-shaped cross section having a large number of small holes 24 is arranged in the inlet chamber 6. The inlet screen plate 25 has a bottom surface which is curved in a substantially semicircular shape and is slidably contacted with the blade 13 of the screw, and both ends are located on both sides of the drum inlet hole 6a, so that the inlet screen plate 25 is arranged so as to entirely surround the inlet hole 6a. You. This cross-sectional shape may be a horseshoe-shaped cross-section other than the U-shape. As shown in FIG. 4B, the small holes 24 of the entrance screen plate 25 are uniformly and relatively densely distributed, and each hole diameter is sufficiently smaller than the through hole 8 of the drum 1. In the entrance room 6, the entrance screen plate 25
No through hole 8 is provided in the peripheral surface of the drum 1 including the inlet hole 6a sandwiched between both ends of the drum.

In the structure of the basic embodiment described above,
When the screw 5 is driven, the rotating shaft 15 is simultaneously rotated by the gear train 14, and the key cam 16 is rotated, so that the small size of the movable plate 11 directly fitted to the opposite peripheral surface of the key cam 16 and the rotating shaft 15. The hole 23 (see FIG. 2) rotates eccentrically, and accordingly, the entire movable plate 11 swings in a range in which the small hole 22 of the vertically extending edge 19 can move around the fulcrum bar 21. In this case, the height of the key cam 16 is set equal to the inner diameter difference between the fixed plate 10 and the movable plate 11, and the difference between the inner diameter of the small hole 22 and the diameter of the fulcrum rod 21 is set substantially equal to this. Plate 11
In the lowermost state shown in FIG. 2, the upper edge of the opening 18 coincides with the opening of the fixed plate 10, that is, the upper end of the inner peripheral surface 12 of the filter cylinder. Opening of the fixed plate 10, that is, the inner peripheral surface 12 of the filter cylinder
And does not enter the inside of the filter cylinder inner peripheral surface 12 during one rotation of the rotary shaft 15.

The treated raw water introduced from the inlet hole 6a is fed into the inlet screen plate 25 of the inlet chamber 6 by a screw 5
Is supplied to the inside of the filter tube 2,
As the filtration proceeds, water is squeezed from the small holes 24 of the screen plate 25, and the water is further discharged from the through holes 8 of the drum 1. The treated raw water gradually squeezed by the screw 5 in the filter tube 2
Is radially filtered through a filter gap that is constantly (slidably) regenerated between the filter and the fixed plate 10, and the filtered water is also discharged from the through hole 8 of the drum 1. Thus, the cake reaching the outlet chamber 7 is discharged from the outlet hole 7a by the squeezing and dehydration of the treated raw water.

FIG. 5 shows a second embodiment in which the rear end of the blade 13 of the screw 5 is stopped before the outlet chamber 7 '(and the end plate 4), which is relatively wide, and the inside of the outlet chamber 7' The valve body 26 fitted on the screw shaft is pressed and urged toward the filter tube 2 by a spring 27 seated on the end surface of the drum 1 to limit the cake discharged from the filter tube 2 into the outlet chamber 7 '. And a discharge control valve 28 for adding the same. Other configurations are the same as those of the basic embodiment shown in FIGS. In this embodiment, the discharge control valve 28 prevents the low-concentration or insufficiently-dehydrated treated material from being discharged as it is at the initial stage of the introduction of the treated raw water into the filtration tube 2, and the filtration proceeds and the treated material ( Only when the pressure of the cake increases, the discharge control valve opens and the discharge of the cake can be started.

[0017]

As described above, the present invention provides a screw drum filtration device having a further increased processing capacity by providing a screen plate in the inlet chamber and providing an auxiliary function of compressing the raw water.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a basic embodiment.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a partial cross-sectional view taken along the line BB of FIG. 2;

FIGS. 4A and 4B are a cross-sectional view of an entrance portion of the basic embodiment and a perspective view showing a screen plate in the entrance portion.

FIG. 5 is a longitudinal sectional view of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drum 2 Filter cylinder 3, 4 End plate 5 Screw 6 Inlet chamber 6a Inlet hole 7 Outlet chamber 7a Outlet hole 8 Through hole 9 Support rod 10 Fixed plate 11 Movable plate 12 Cylindrical inner peripheral surface 13 Blade 14 Gear train 15 Rotating shaft 16 Key cam 24 Small hole 25 Screen plate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 11/12 B01D 29/42 510 520

Claims (2)

[Claims] 1. a) In a substantial range excluding both ends in a drum, a large number of annular fixed plates and an opening diameter slightly larger than the opening diameter of the fixed plate, and having an amplitude corresponding to a difference in the diameter. With a large number of movable annular plates that can move, a filter tube that is composed of an alternately superposed array with a small gap for each filtration and that defines a fixed cylindrical space by the row of openings of the fixed plate, b) a screw penetrating through the cylindrical space of the filter cylinder is disposed over substantially the entire length of the drum, and a mechanism for swinging the movable plate by rotation of the screw is provided; c) one end of the drum and Between the other end of the filtration tube and the other end of the filtration tube, and between the other end of the drum and the other end of the filtration tube facing the other end to the drum exit hole. An outlet chamber for the processed cake, and a plurality of through-holes disposed on the drum except for at least the outlet chamber to form a drain port. D) In the inlet chamber, a bottom surface that is curved in a substantially semicircular shape is formed. A screw drum type filtration device comprising a U-shaped or horseshoe-shaped cross-section inlet screen plate having a number of small holes arranged in sliding contact with the blades of the screw so as to entirely surround the drum inlet hole. 2. A blade discharged from the other end of the filter tube into the outlet chamber is restricted by a valve body fitted to a screw shaft in the outlet chamber, with a rear end of a blade of the screw being stopped before the outlet chamber. The filtration device according to claim 1, further comprising a discharge control valve.