JP2001300215A - Running filter cloth type waste liquid treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a running filter cloth type waste liquid treatment apparatus for continuously filtering and concentrating sludge by using endless running filter cloth while sufficiently ensuring the intrinsic function of the filter cloth and reducing the abrasion of the filter cloth to extend the life thereof. SOLUTION: An air blowing-off device 34 for forming an air bubble belt by air bubbles is provided between the surfaces of the opening parts 29 with which the running filter cloth 30 constituting the waste liquid treatment apparatus 22 is brought into contact. The air blowing-off device 34 is constituted of an air blow-off pipe 34 having nozzles 34b and a compressor 42. The air bubble belt 43 forms air bubbles forcibly to bond air bubbles to the rear surface of the running filter cloth 30 brought into contact with the opening parts 29 to prevent the direct contact of the opening parts 29 with the running filter cloth 30 on a constant track. By this constitution, the abrasion of the running filter cloth 30 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid treatment apparatus for continuously filtering and condensing sludge generated in a sewage treatment plant or the like by an endless traveling filter cloth (hereinafter referred to as a traveling filter cloth type waste liquid treatment apparatus).

[0002]

2. Description of the Related Art Generally, in wastewater treatment in a sewage treatment plant or the like, as shown in FIG. The clear water is supplied to the reaction tank 2 where it is treated with activated sludge. The activated sludge-treated clear water is again solid-liquid separated in the final settling basin 3 by gravity settling. The clear water is in sterilization tank 4
Where it is sterilized. Then, the sterilized treated water is discharged to rivers, lakes, or sea areas. On the other hand, the settling sludge from the first settling tank 1 and the excess sludge from the final settling tank 3 are usually mixed and supplied to the sludge thickening tank 5. The solid matter concentration of the mixed sludge supplied to the sludge thickening tank 5 is usually about 1%. Mixed sludge is sludge thickening tank 5
To obtain concentrated sludge having a solid concentration of about 2% to 3%. The concentrated sludge is stored in the sludge storage tank 6. The concentrated sludge stored in the sludge storage tank 6 is dewatered by the dehydrator 7 to obtain a dewatered cake.

The above-described waste liquid treatment method by gravity sedimentation has the advantage that the treatment cost can be reduced because the power consumption is small. However, the waste liquid treatment apparatus by gravity sedimentation has a large installation area, and the treatment capacity of the apparatus greatly depends on the properties of sludge and the water temperature. In particular, in recent years, the sedimentability of sludge has been degraded due to an increase in organic components in the waste liquid or decay of the waste liquid during long-distance transportation due to the intensive treatment of waste liquid. As a result, in the sludge concentration tank of the waste liquid treatment plant where the waste liquid is concentrated, it is difficult to constantly secure concentrated sludge having a solid concentration of 2% or more by gravity sedimentation treatment. When the concentrated sludge of a predetermined concentration cannot be obtained, not only the safe operation of the dehydrator is difficult in the subsequent dewatering treatment equipment, but also excessive dewatering treatment equipment is required.

As an example for solving such a problem, Japanese Patent Application Laid-Open No. H11-216312 discloses a traveling filter cloth type waste liquid treatment apparatus as shown in FIG.

FIG. 8 is a schematic perspective view of a waste liquid processing apparatus.
The traveling filter cloth type waste liquid treatment apparatus is configured such that a waste liquid chamber 8 having a waste liquid supply port 9 and a concentrated waste liquid discharge port 10 and a filtrate chamber 11 having a filtrate discharge port 12 are adjacent to each other.

[0006] The waste liquid level in the waste liquid chamber 8 is always higher than the waste liquid level in the filtrate chamber 11 by a predetermined height, and the waste liquid in the waste liquid chamber 8 is filtered by the filtration means 15.
1, the supply and discharge of the waste liquid and the discharge of the filtrate are adjusted.

The filtrate chamber 11 has a projection 13 protruding in a U-shape within the waste liquid chamber 8, and a lattice-shaped opening 14 communicating with the waste liquid chamber 8 is formed on a side wall of the projection 13 opposite to the projection 13. Is formed.

The filtering means 15 is for filtering the waste liquid supplied to the waste liquid chamber 8, and includes a filter cloth 1 made of polyester or the like.
8 is configured to run endlessly in a vertical direction between the upper roller 17 (drive roller) and the lower roller 16 while covering the opening 14.

Reference numeral 19 denotes cleaning means for cleaning the filter cloth 18, reference numeral 20 denotes sludge adhesion amount detecting means,
Reference numeral 21 denotes speed control means.

According to the above-mentioned waste liquid treatment apparatus, when the mixed sludge flows into the waste liquid chamber 8, the sludge is filtered by the continuously running filter cloth 18, and is passed through the opening 14 into the filtrate chamber 11. Flows naturally into Since the filter cloth 18 travels while covering the opening 14, there is no possibility that the mixed sludge in the waste liquid chamber 8 directly flows into the filtrate chamber 11. by this,
The sludge in the waste liquid chamber 8 is concentrated. The concentrated sludge is discharged from the concentrated waste liquid discharge port 10 to the outside of the waste liquid chamber 8, and the filtrate flowing into the filtrate chamber 11 is discharged from the filtrate discharge port 12 to the outside of the filtrate chamber 11. Collected.

As the filtration proceeds, the sludge cake adheres to and accumulates on the filter cloth 18. The sludge cake is sequentially removed by the washing means 19. Therefore, the filtering means 15 is always operated without reducing the filtration efficiency of the filter cloth 18.
Stable operation.

[0012]

However, the traveling filter cloth type waste liquid treatment apparatus described above has the following problems. Filtration means 15 used in the waste liquid treatment apparatus, while a filter cloth 18 made of polyester or the like covers the opening 14 formed in the filtrate chamber,
It travels endlessly in a vertical direction between the upper roller 17 and the lower roller 16, during which waste liquid is filtered to form concentrated sludge.

[0013] During continuous filtration and concentration of the waste liquid sludge,
The endless filter cloth 18 continuously runs around a fixed orbit by the upper roller 17, the lower roller 16, and the opening 14, and is in direct contact with them, so that it is gradually worn. In this case, contact with the opening 14 particularly affects wear.

As one means for preventing abrasion of the filter cloth,
It is conceivable to select a material having a low wear coefficient and a high breaking strength. However, a filter cloth is required. There is a limit in selecting a filter cloth of a material that simultaneously satisfies conditions such as high efficiency. To obtain it, there is a problem that the filter cloth becomes unnecessarily expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an endless filter cloth which is provided adjacent to a waste liquid chamber and a filtrate chamber having an opening, and travels around a fixed track. To provide a traveling filter cloth type waste liquid treatment apparatus that can sufficiently secure the original function of the filter cloth, reduce the wear of the filter cloth, and prolong the service life, for a waste liquid treatment apparatus that continuously filters and concentrates sludge by filtration. With the goal.

[0016]

According to the first aspect of the present invention,
In the waste liquid treatment apparatus, a waste liquid chamber and a filtrate chamber having an opening are provided adjacent to each other, and the sludge is continuously filtered and concentrated by an endless filter cloth circulating on a fixed orbit including the opening. A traveling filter cloth type waste liquid treatment apparatus, wherein an air blowing device for forming a bubble belt is provided between the filter cloth and an opening surface with which the filter cloth contacts.

According to the present invention, an air blowing device for forming a bubble belt between the opening filter and the opening surface with which the traveling filter cloth comes into contact is provided so that the filter cloth main body is not directly contacted with the opening by the bubble belt. Therefore, wear of the traveling filter cloth can be prevented, and the life thereof can be extended.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the air blowing device is provided on the traveling filter cloth side at the lower end of the opening.

According to the present invention, the air blowing device is provided on the traveling filter cloth side at the lower end of the opening, and blows air to the inside of the traveling filter cloth to attach air bubbles to form a bubble belt between the opening and the opening. As a result, wear of the traveling filter cloth can be prevented, and its life can be extended.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 are schematic perspective views showing an embodiment according to the present invention, FIG. 1 is a schematic perspective view of a traveling filter cloth type waste liquid treatment apparatus viewed from a sludge supply side, and FIG. It is the schematic perspective view which has a notch of the traveling filter cloth type waste liquid processing apparatus seen from. FIG. 3 is a cutaway schematic perspective view showing an example of the arrangement of the air blowing device as viewed from the direction of arrows AA in FIG.

FIG. 4 is an explanatory view of a bubble belt according to the present invention. Raw sludge generated at the sewage treatment plant was used as the waste liquid.

In FIG. 1 and FIG.
Is configured such that a waste liquid chamber 23 having a waste liquid supply port 24 and a concentrated waste liquid discharge port 25 and a filtrate chamber 26 having a filtrate discharge port 27 are adjacent to each other.

The level of the waste liquid in the waste liquid chamber 23
The waste liquid in the waste liquid chamber 23 is allowed to flow naturally into the filtrate chamber 26 by the filtration means 28 so that the waste liquid level is always higher than the waste liquid level therein by the predetermined height, and supply and discharge of the waste liquid and discharge of the filtrate are adjusted. are doing.

The filtrate chamber 26 has a projection 26a projecting in a U-shape in the waste liquid chamber 23, and a lattice-shaped opening 29 communicating with the waste liquid chamber 23 is formed on the opposite side wall of the projection 26a. Is formed.

The filtering means 28 is for filtering the waste liquid supplied to the waste liquid chamber 23. The driving filter 37 covers the opening 29 with the traveling filter cloth 30 made of polyester or the like.
It is configured to run endlessly in a vertical direction between an upper roller 31 (drive roller) and a lower roller 32 connected to the motor.

A filter cloth tensioning device 35 and a meandering correction device 36 are provided on a fixed track so as to enable smooth round running.

Reference numeral 33 denotes cleaning means for cleaning the traveling filter cloth 30. In addition, a sludge adhering amount detecting means (not shown), a speed control device, and the like are connected. Reference numeral 38 denotes a deodorizing cover.

In the present invention, an air blowing device 34 for forming a bubble belt by bubbles between the running filter cloth 30 and the surface of the opening 29 which makes up the waste liquid treatment device 22 described above.
Is provided.

The air blowing device 34 comprises an air blowing pipe 34a having a nozzle 34b and a compressor 42. In the embodiment of FIGS. 1 to 3, the air blowing pipe 34 a of the air blowing device 34 is disposed on the traveling filter cloth side at the lower end of the opening 29, but the present invention is not limited to this. Any arrangement can be used as long as the bubble belt can be formed on the contact surface with the traveling filter cloth in contact. Further, the opening is not limited to the lattice shape, and may be any shape as long as the waste liquid can be filtered by the traveling filter cloth.

As shown in FIG. 4, the bubble belt 43 forcibly forms bubbles, attaches the bubbles to the back side of the traveling filter cloth 30 in contact with the opening 29, and moves the traveling filter cloth 30 over a fixed orbit. This prevents the running filter cloth 30 from being worn in place of the running filter cloth 30 by preventing direct contact with the opening 29.

That is, the bubble belt 43 does not merely raise bubbles, but plays the role of a bubble belt on the surface where the back side of the traveling filter cloth 30 contacts the opening 29, that is, on a lattice frame, etc. Filtration chamber 26 as bubbles with the liquid
And rise. Therefore, it does not affect the filtration of the waste liquid by the traveling filter cloth 30 at all.

According to the waste liquid treatment apparatus 22 described above, when the raw sludge flows into the waste liquid chamber 23 through the sludge distribution partition 47 as shown by the thick arrow, the sludge content is reduced as shown by the thick arrow.
The water is filtered by the traveling filter cloth 30 running continuously, and naturally flows into the filtrate chamber 26 from the opening 29. Since the traveling filter cloth 30 travels while covering the opening 29, there is no possibility that the raw sludge in the waste liquid chamber 23 directly flows into the filtrate chamber 26. Thereby, the sludge in the waste liquid chamber 23 is concentrated. The concentrated sludge enters the chute 41 via the overflow 40, is discharged from the concentrated waste liquid discharge port 25 to the outside of the waste liquid chamber 23, and the filtrate flowing into the filtrate chamber 26 is discharged to the filtrate discharge port. The liquid is discharged from the filtrate chamber 26 to the outside of the filtrate chamber 26 and is collected.

As the filtration proceeds, the traveling filter cloth 30
The sludge cake adheres to and accumulates on the surface, and this sludge cake is sequentially removed by the washing means 33. Therefore,
The filtering means 28 can be used without reducing the filtration efficiency of the filter cloth 30.
Is always operated stably. Reference numeral 39 indicates a scraper.

In the filtering means 28, the traveling filter cloth 30 is
While running around the upper roller 31 and the lower roller 32 endlessly in a vertical direction while covering 9, the bubble belt 43 is formed between the upper roller 31 and the lower roller 32 and the opening surface with which the traveling filter cloth comes into contact. Wear due to contact with the opening 29 does not occur.

Therefore, according to the traveling filter cloth type waste liquid treatment apparatus of the present invention, the traveling filter cloth can be selected mainly based on the conditions required for the filtration of the waste liquid, so that the filter cloth material can be obtained at low cost.

FIG. 5 is a cutaway schematic perspective view showing another example of the arrangement of the air blowing device used in the present invention, and FIG. 6 is an explanatory view of the bubble belt formed according to FIG. Figures 3 and 4
The same reference numerals are given to the parts common to and the description thereof is partially omitted.

The air blowing device 44 has an air blowing tube 45a having a plurality of nozzles 45b forming a vertical bar of the opening 29.
And a main pipe 45c for distributing compressed air to the air blowing pipe 45a
When compressed air is supplied to the main pipe 45c, the main pipe 45c is constituted by the compressor 42. The horizontal rail of the opening 29 is used as a reinforcing material. However, the horizontal rail can also be formed as an air blowing pipe if necessary.

The air blowing pipes 45a are provided on the vertical rails on the sludge supply side and the concentrated sludge discharge side of the opening 29. In general, since the traveling filter cloth travels in the vertical direction while being in contact with the longitudinal crosspieces, constitutes a vertical bar at the air outlet pipe 45a, blowing air from the nozzle 45 b of the air discharge pipe 45a, the bubbles belt 46 easily Can be formed. The bubble belt 46 is, as shown in FIG.
Air is forcibly blown out from the plurality of air blowing pipes 45a to form air bubbles, and the air bubbles are adhered to the back side of the traveling filter cloth 30 that comes into contact with the air blowing pipes 45a in the openings 29, so that the air directly flows into the air blowing pipes 45a. To avoid contact with the running filter cloth 30.
To prevent abrasion.

[0039]

As described above, according to the present invention, a waste liquid chamber and a filtrate chamber having an opening are provided adjacent to each other, and the sludge is continuously filtered by an endless traveling filter cloth which runs around a fixed track. For the waste liquid treatment device to be concentrated, the simple function of providing an air blowing device to form an air bubble belt between the opening surface and the running filter cloth is in contact with the filter cloth. Reduce the wear of the filter cloth,
Life can be extended.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment according to the present invention as viewed from a sludge supply side.

FIG. 2 is a schematic perspective view seen from the sludge extraction side on the back side of FIG.

FIG. 3 is a cutaway schematic perspective view showing an example of the arrangement of the air blowing device as viewed from the direction of arrows AA in FIG. 1;

FIG. 4 is an explanatory diagram showing an example of a bubble belt used in the present invention.

FIG. 5 is a cutaway schematic perspective view showing another example of the arrangement of the air blowing device used in the present invention.

FIG. 6 is an explanatory view of a bubble belt formed according to FIG. 5;

FIG. 7 is a flowchart showing a conventional wastewater treatment method in a sewage treatment plant.

FIG. 8 is a schematic perspective view showing an example of a conventional traveling filter cloth type waste liquid treatment apparatus.

[Explanation of symbols]

 Reference Signs List 22 Waste liquid treatment device 23 Waste liquid chamber 24 Waste liquid supply port 25 Concentrated waste liquid discharge port 26 Filtration chamber 27 Filtrate discharge port 28 Filtration means 29 Opening 30 Running filter cloth 31 Upper roller 32 Lower roller 33 Cleaning means 34, 44 Air blowing device 34a, 45a Air blowing tube 34b 45b nozzle 35 Filter cloth tensioning device 36 Meandering correction device 37 Drive device 38 Odor control cover 39 Scraper 40 Overflow weir 41 Chute 42 Compressor 43, 46 Bubble belt 45b Main pipe 47 Sludge distribution

Claims (2)

[Claims] 1. A waste liquid treatment apparatus for providing a waste liquid chamber and a filtrate chamber having an opening adjacent to each other and continuously filtering and condensing sludge with an endless filter cloth circulating on a fixed orbit including an opening. A traveling filter cloth type waste liquid treatment apparatus, further comprising an air blowing device for forming a bubble belt between the traveling filter cloth and an opening surface with which the filter cloth contacts. 2. The traveling filter cloth type waste liquid treatment apparatus according to claim 1, wherein the air blowing device is provided on the traveling filter cloth side at the lower end of the opening.