JP2003334403A - Discharge apparatus for precipitate in precipitation tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge apparatus for precipitate capable of coping with fluctuation of precipitate such as sludge, excretion residue or the like precipitated on the bottom of a precipitation tank. <P>SOLUTION: A scraping screw (6) is connected to the rotary cylinder (5) vertically provided to the center part of the precipitation tank (1) and the precipitate on the tank bottom (1a) is scooped up by a scraper (11) to be allowed to flow in a screw outer cylinder (8) from a flooding port (8a) and transferred to the rotary cylinder (5) by a screw (9). If the running speed of the scraping screw (6) and the rotational speed of the screw (9) are adjusted, the precipitate such as sludge, excretion residue or the like deposited on the tank bottom (1a) is forcibly accumulated in the rotary cylinder (5). Since a spiral blade (20) is arranged to the discharge pump (17) suspended in the rotary cylinder (5), a suction port (21a) wide on the inside of a leading end is formed to form a pump excellent in foreign matter passing properties and, since the spiral blade (20) forms a smooth flow channel, the entanglement with fibrous foreign matter is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a settling tank for settling and separating sludge generated from a water purification plant or a sewage treatment plant, or industrial wastewater. The present invention relates to a device for discharging a precipitate discharged outside the tank.

[0002]

2. Description of the Related Art Generally, a sewage treatment facility for treating various effluents is equipped with a settling tank for separating sewage into a supernatant and a settling sludge. The sediment that has settled on the bottom of the settling tank is scraped by a rotary rake installed in a cylindrical settling tank into the mud collecting pit at the center of the bottom of the tank and discharged from the sludge extraction pipe by a sampling pump or the like. The discharging device of Japanese Patent Application Laid-Open No. 9-29 is, for example,
It is known as described in Japanese Patent Publication No. 9713.

[0003]

The conventional rotary rake is
If the raw water contains a large amount of sludge or sludge due to seasonal fluctuations, the rake will be buried in the separated sediment, which will increase the scraping resistance and cause a drive failure, making it impossible to drive. Also,
When a large amount of residue was included in the precipitate, the scraping resistance increased and a running problem occurred. If there is no appropriate scraping speed, the sediment does not move to the center, and if the speed is increased, the sediment will idle at the bottom of the tank below the sediment. The present invention provides a sediment discharging device which comprises a scraping machine of a sedimentation tank with a scraping screw and can cope with fluctuations in sludge and sludge in raw water.

[0004]

A sediment discharging apparatus for a sedimentation tank according to the present invention is a sedimentation apparatus for collecting sediment deposited on the bottom of a sedimentation tank in the center of the tank and discharging the sediment outside the tank. , A scraping screw is connected to a rotating cylinder vertically installed at the center of the settling tank, an overflow port is opened in the screw outer cylinder of the scraping screw, and the tip of the scraper is slid on the bottom of the tank. In addition to fixing, a screw for collecting mud is arranged in the screw outer cylinder, and a mud discharge device is arranged inside the rotating cylinder, which corresponds to the fluctuation of sludge and residue in the raw water. By adjusting the traveling speed of the scraping screw and the rotation speed of the screw, it is possible to accumulate the sediment such as sludge and sludge accumulated on the bottom of the tank on the rotary cylinder. Even if the speed is slowed down, the scraping area of the scraping screw is small, so that the running resistance is small and the operation is not hindered. Further, even if the amount of the precipitate is large, the traveling speed is slowed down and the rotation speed of the screw is increased, whereby the precipitate at the bottom of the tank can be completely discharged.

If the sludge discharge device for the sediment collected in the central portion of the tank bottom is a discharge pump hanging near the tank bottom of the rotary cylinder,
The precipitate accumulated in the rotary cylinder can be sucked up and discharged outside the tank. In this impeller of the discharge pump, a plurality of spiral blades are fixed to a conical hub, and the tip of the outer periphery of these spiral blades is extended to near the suction port of the pump casing. A wide suction port is formed on the inside, making it a pump with excellent foreign matter passage properties and improving suction performance. Further, since the spiral blade forms a smooth flow path, the fibrous foreign matter is not entangled, and the pressure is increased to form a high-lift pump. Further, the spiral blades are axially symmetrically arranged in good balance to improve volume efficiency and rotational balance. If the sludge drainage device, instead of a discharge pump, hangs down near the tank bottom of the rotating cylinder as a discharge screw consisting of a cylindrical casing with an open lower end, and a screw for sludge inscribed in the cylindrical casing, If the excess water of the accumulated precipitate is separated by the head pressure and the rotation speed of the screw is adjusted, the discharge amount of the precipitate can be easily adjusted. Further, since the screw forms a continuous flow path, the screw does not get tangled with residue.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION When a precipitate screwed on the bottom of a settling tank is caused to run by a scraping screw around a rotary cylinder,
The scraper that slides in contact with the bottom of the tank scoops up the precipitate and flows it into the overflow port of the screw outer cylinder. The screw for collecting mud conveys the precipitate that has flowed into the outer cylinder of the screw toward the center and causes it to flow into the lower part of the rotary cylinder. The deposit transferred to the rotary cylinder is discharged to the outside of the settling tank by the discharge pump or the discharge screw hanging down on the rotary cylinder. The scraping screw can adjust the discharge amount of the precipitate by adjusting the traveling speed around the rotating cylinder and the rotating speed of the screw provided inside the screw outer cylinder. Even if a large amount of sediment is precipitated due to seasonal fluctuation, it can be completely discharged by slowing the rotation speed of the scraping screw and increasing the rotation speed of the screw. It does not idle below the sediment and is not buried in the sediment and causes drive failure. Even if a large amount of residue flows into the screw outer cylinder, the screw forms a series of flow paths and can be forcibly conveyed by the screw.

[0007]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical side view of a settling tank. In the settling tank 1, a tank bottom 1a is formed in a conical shape and a central portion is lowered. is there. An end of a raw water inflow pipe 3 is opened in an annular center well 2 arranged at the center of the settling tank 1, sludge in the supplied stock solution is allowed to settle on the tank bottom 1a, and the separated supernatant water is settling tank 1 It is discharged from the overflow weir 4 arranged at the upper peripheral portion of the. A scraping screw 6 arranged obliquely along the bottom 1a of the settling tank 1 is connected to a rotary cylinder 5 vertically provided at the center of the settling tank 1, and the lower part of the rotary cylinder 5 and the scraping screw 6 are connected. The base end of is communicated. Reference numeral 7 is a support rod in which the intermediate portion of the scraping screw 6 is suspended from the rotary cylinder 5.

As shown in FIG. 1, the scraping screw 6 has a screw outer cylinder 8 provided with a screw 9 for collecting mud, and a screw driving machine 10 for an underwater motor supported at the tip of the screw outer cylinder 8. A screw 9 is connected to. FIG. 3 is a vertical cross-sectional view of the scraping screw. An overflow port 8a is opened in the outer cylinder of the screw along the bottom of the screw, and its tip is slid on the bottom of the overflow port 8a. The scraper 11 installed is fixed. FIG. 2 is an enlarged view of the rotary cylinder, in which the rotary cylinder 5 is supported by a pedestal 12 disposed above the settling tank 1, and the lower end of the rotary cylinder 5 is a recess formed in the center of the tank bottom 1a. The bearing 13 is pivotally supported. Stand 1
A driven gear 16 fitted to the peripheral portion of the rotary cylinder 5 is meshed with a drive gear 15 of the rotary drive machine 14 supported by 2.

A rotation driving machine 14 causes a scraping screw 6 to run along the bottom 1a of the settling tank 1 around the rotary cylinder 5, and a scraper 11 slidingly contacting the bottom 1a of the settling tank 1 brings the bottom 1a of the settling tank 1 to the bottom. The accumulated sludge and sludge residue is scooped up and made to flow into the overflow port 8a of the screw outer cylinder 8. At the same time, the screw 9 for collecting mud that is rotated by the screw driver 10 transfers the precipitate that has flowed into the screw outer cylinder 8 toward the base end, and causes the precipitate to flow into the lower part of the rotary cylinder 5. By adjusting the traveling speed of the scraping screw and the rotation speed of the screw 9, the precipitate accumulated on the tank bottom 1a can be accumulated in the rotating cylinder. Even if the amount of settled sludge is large, the precipitate can be discharged by slowing the rotation speed of the scraping screw 6 and increasing the rotation speed of the screw 9. Even if the speed is reduced, the scraping area of the scraping screw 6 is small, so that the running resistance is small and the operation is not hindered. Also,
Even if the amount of the sediment is large, the traveling speed is slowed down and the rotation speed of the screw 9 is increased, whereby the sediment on the bottom 1a of the tank can be completely discharged. Even if a large amount of residue flows into the screw outer cylinder 8, it can be forcibly conveyed by the screw 9 that forms a series of flow paths.

As shown in FIG. 2, a discharge pump 17 is disposed inside the rotary cylinder 5 and hangs down near the tank bottom 1a. As shown in FIG. 4, the impeller 18 of the discharge pump 17
Has a plurality of spiral blades 20 ... Attached to a conical hub 19 at regular intervals with a phase shift, and the spiral blades 20 are axially symmetrically arranged in a well-balanced manner to apply energy to a fluid. As a result, the volume efficiency and rotation balance are improved. The outer peripheral tip of the spiral blade 20 is connected to the suction port 2 of the pump casing 21.
It is extended to the vicinity of 1a, and a wide suction port is formed on the inner side of the tip to improve the suction performance and facilitate the passage of foreign matter such as residue. Further, since the spiral blade forms a smooth flow path, fibrous foreign matter such as residue does not get entangled, and the pressure is increased to form a high-lift pump. Pump casing 2
A guide vane 23 for rectifying the swirling flow pressurized by the impeller 18 is provided in the discharge casing 22 at the rear stage of the vane 1, and the vane boss 24 fixed to the guide vane 23 serves to impeller 18
A drive shaft 25 connected to the shaft is supported. The upper end of the drive shaft 25 is interlockingly connected to the pump driver 26. The discharge casing 22 is connected to the pump pipe 27, and the impeller 18
The sediment that has been sucked in is transferred to the pump pipe 27,
The sediment is discharged to the outside of the settling tank 1 from the sludge pipe 28 connected to.

FIG. 5 shows another embodiment of the sludge discharging device, in which the discharging screw 29 is arranged inside the rotary cylinder 5 vertically provided at the center of the settling tank 1, as shown in FIG. The discharge screw 29 has an upper end suspended from the pedestal 12 and is attached to the rotary cylinder 5.
A cylindrical casing 30 that hangs down near the tank bottom 1a and has an open lower end, and a screw 32 for sludge sludge inscribed in the cylindrical casing 30 that is interlockingly connected to a discharge driving device 31 that is supported on the upper end of the cylindrical casing 30. The precipitate that has settled on the bottom 1a of the settling tank 1 is caused to flow into the lower part of the rotary cylinder 5 by the scraping screw 6, and the screw 32 of the discharge screw 29 is rotated to transfer the precipitate upward. Then, the sediment is discharged from the sludge pipe 28 to the outside of the settling tank 1. The discharge screw 29 having the upper end suspended from the gantry 12 separates excess water of the accumulated precipitate by head pressure and adjusts the rotation speed of the screw 32 to easily adjust the amount of discharge of the precipitate. Become. Since the screw 32 forms a continuous flow path, the screw 32 will not be entangled with residue or the like.

[0012]

The deposit discharging device according to the present invention is configured as described above, and if the traveling speed of the scraping screw and the rotation speed of the screw are adjusted in accordance with the fluctuation of the precipitate, the precipitate is discharged. The discharge amount of the sediment that has settled on the bottom of the tank can be adjusted. That is, in the conventional discharge device for collecting the sludge by the rotary rake, the rake is buried in the sediment due to an increase in the sediment such as sediment sludge and sludge, which increases the scraping resistance, which is a driving obstacle. In addition, there is a drawback that the sediment cannot be scraped well by spinning below the sediment, but in the present invention, a scraping screw is attached to a rotary cylinder vertically installed at the center of the sedimentation tank. Connect, while rotating the draw screw, let the precipitate flow into the screw outer cylinder,
Since the screw forming a series of flow paths inscribed in the screw outer cylinder is forcibly conveyed to the central portion, the precipitate deposited on the bottom of the tank can be accumulated in the rotary cylinder. And
Even if a large amount of sediment is deposited, it is possible to discharge the sediment by slowing the traveling speed of the scraping screw and increasing the rotation speed of the screw.

The deposit accumulated in the central portion of the bottom of the tank can be sucked up and discharged outside the tank by using a discharge pump hanging down near the bottom of the rotary cylinder. In this impeller of the discharge pump, a plurality of spiral blades are attached to a conical hub with their phases being equidistantly spaced and fixed, and the outer peripheral tip of this spiral blade is located near the suction port of the pump casing. If it is extended up to a point, a wide suction port is formed on the inner side of the tip to form a pump having excellent foreign matter passing property, and the suction performance is improved.
Further, since the spiral blade forms a smooth flow path, the fibrous foreign matter is not entangled, the pressure is increased, and the discharge pump has a high head with good volume efficiency and rotational balance. Also,
Instead of a discharge pump, if it hangs down near the tank bottom of the rotating cylinder as a discharge screw, excess water of the accumulated precipitate is separated by head pressure, and if the screw rotation speed is adjusted Adjustment becomes easy. Further, the screw forming the continuous flow path does not get entangled with the residue.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view of a sediment discharging device in a sedimentation tank according to the present invention.

FIG. 2 is likewise an enlarged view of a main part of the deposit discharging device.

FIG. 3 is likewise a vertical cross-sectional view of a scraping screw.

FIG. 4 is likewise a partial vertical side view of the impeller of the discharge pump.

FIG. 5 is a partial vertical cross-sectional side view of a deposit discharge device according to another embodiment of the present invention.

FIG. 6 is an enlarged view of a main part of a deposit discharging device according to another embodiment.

[Explanation of symbols]

1 settling tank 1a Tank bottom 5 rotating cylinder 6 scraping screw 8 screw outer cylinder 8a Overflow outlet 9, 32 screws 11 scrapers 17 Discharge pump 18 impeller 19 hub 20 spiral wings 21 Pump casing 21a Suction port 29 Discharge screw 30 cylindrical casing

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04D 7/04 F04D 7/04 H J

Claims (4)

[Claims] 1. A settling device that collects the sediment deposited on the bottom (1a) of the settling tank (1) in the center of the tank and discharges it to the outside of the tank, which is vertically installed at the center of the settling tank (1). Rotating cylinder (5)
The scraping screw (6) is connected to, and the overflow port (8a) is opened in the screw outer cylinder (8) of the scraping screw (6), and the tip of the overflow port (8a) is the bottom of the tank (1a). The scraper (11) slid on the wall is fixed, the screw (9) for collecting mud is arranged on the screw outer cylinder (8), and the mud discharge device is arranged inside the rotary cylinder (5). A discharge device for a sediment in a sedimentation tank, which is characterized in that 2. The discharge of sediment in a settling tank according to claim 1, wherein the sludge discharge device is a discharge pump (17) hanging near the tank bottom (1a) of the rotary cylinder (5). apparatus. 3. The impeller (1) of the discharge pump (17)
8) has a conical hub (19) with a plurality of spiral blades (2).
0) is attached and the outer peripheral tip of the spiral blade (20) is extended to the vicinity of the suction port (21a) of the pump casing (21). Discharge device in the settling tank. 4. The sludge discharging device comprises a cylindrical casing (30) which hangs down near a tank bottom (1a) of a rotary cylinder (5) and has a lower end opened, and sludge for sludge inscribed in the cylindrical casing (30). Of the discharge screw (2
9) The discharge device for deposits in a settling tank according to claim 1, characterized in that