JP2000117003A - Upward and downward counter-current concentrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat the precipitable sludge having the same specific gravity as water by a gravity type and to treat the floatable sludge having the specific gravity lower than that of water by a floating type with a single device by arranging a partition cylinder, a partition conical part, a floated sludge discharge plate and a floated sludge discharge passage, mounting an arm and a floated sludge scraper at a driving shaft and disposing an air dispersing pipe in a water introducing pipe. SOLUTION: In this concentrator 1, the sludge is made to flow from a raw water inflow pipe 8 into the introducing pipe 15 providing with the air dispersing pipe and in which air bubbles are brought into contact and combined with sludge floc, and the precipitable sludge having the specific gravity more than 1 is deposited on a bed board 10 by the gravity and collected in a sludge pit 12 with the driving shaft 18 and the scraper 11 and discharged to the outside of system through a sludge transfer pipe 13. The sludge floated by the upward stream at the water introducing pipe 15 and a contaminated water tank 3 is collected on the water surface of a water tank and transferred with a floated sludge discharge plate 5 and a floated sludge scraper 20 via floated sludge passage 21. A separated liq. from which the sludge is separated at the contaminated water tank 3 is transported from a separated liq. passage 7 via a separated water tank 6. In this way, the device enables to cope with the single concentrator 1 according to the precipitable sludge or the floatable sludge due to quality change and the value of the gravity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the primary treatment of incoming sewage such as sewage, agricultural settlement drainage, and industrial wastewater, and the concentration of sludge generated from secondary treatment, and belongs to the field of water treatment.

[0002]

2. Description of the Related Art Conventionally, there are three methods for concentrating sludge generated from primary treatment and secondary treatment of wastewater: gravity type, mechanical type (centrifugal concentrator), and floating type. (1) The gravity method is the most general method, and is used to settle sludge by natural gravity. It is effective when the specific gravity of the sludge is greater than 1, and has an advantage of not using energy. However, it takes time to perform sedimentation and separation, and it is necessary to enlarge the concentration tank. When the specific gravity of the sludge is smaller than 1, no settling is performed, so that the treatment becomes impossible. In recent years, in the case of sewage and the like, there are many cases in which the quality of sludge is organic, and the generated sludge tends to be floating. (2) The mechanical method is mainly a centrifugal concentration method, and the specific gravity of sludge is naturally larger than 1, and even smaller than 1 is often used because of its good concentration effect. Since it consumes a lot and rotates at high speed, it is necessary to take measures to prevent secondary pollution such as noise and vibration.
In some cases, a coagulant is used. (3) The levitation type is mainly for efficiently raising buoyant sludge having a specific gravity of less than 1, and there are a pressurization type and a normal pressure type, but both increase the buoyancy by contacting fine air bubbles with the sludge and combining them. And lift it up for recovery.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to provide a concentrating apparatus which can cope with any sludge generated in the primary treatment and the secondary treatment. That is, it is an object of the present invention to use one apparatus to deal with settling sludge having a specific gravity of more than 1 by a gravity method, and to deal with floating or floating sludge having a specific gravity of less than 1 by using a floating method.

[0004]

Means for Solving the Problems In the gravity type concentration tank 1, a partition cylinder 2, a partition cone portion 4, and a floating sludge discharge plate 5 are provided, and a drive shaft 18 has an arm 19 and a floating sludge scraper 20.
And a floating sludge drainage channel 21 is installed. Next, an air diffuser 16 is provided in the water pipe 15 and connected to an air source.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to
In the gravity type concentrating tank 1, which collects and accumulates in a sludge pit 12 by a scraper 11 and transfers the collected sludge to the outside of the system, floating or buoyant sludge flows upward in a water pipe 15 and a polluted water tank 3. Float, accumulate near the water surface,
This sludge is introduced into the sludge channel 21 via the floating sludge discharge plate 5 by the floating sludge scraper 20 and transferred out of the system.
Both settling and floating sludge can be treated. Also,
As a method of bringing air bubbles and sludge flocs into contact and combining them in order to improve the floating property of the suspended or floating sludge, an air diffuser 16 is provided in the water pipe 15 to diffuse air. Further, a method is employed in which air is directly introduced into the raw water inflow pipe 8 and mixed with sludge.

[0006]

FIG. 1 shows an embodiment of the present invention. In a concentration tank 1, sludge flows from a raw water inflow pipe 8 into a water conveyance pipe 15, and settled sludge having a specific gravity of more than 1 is converted into a floor bed 1 by gravity.
When the sediment is deposited on the zero, it is collected in the sludge pit 12 by the drive shaft 18 and the scraper 11 and is transferred out of the system by the sludge transfer pipe 13. The sludge that floats in the water pipe 15 and the polluted water tank 3 accumulates on the water surface of the tank, flows into the floating sludge channel 21 by the floating sludge discharge plate 5 and the floating sludge scraper 20, and is transferred. The separated liquid separated from the pollutants in the polluted water tank 3 is separated from the separated water tank 6.
Flows into the separated liquid channel 7 and is carried out. In this way, sludge due to downward flow and upward flow is eliminated in a single tank. FIG. 2 shows an example in which an air diffuser for improving levitation is provided in the concentration tank. Water pipe 15
A diffuser tube 16 is provided in the inside, and is connected to the air tube 9. Diffuser 1
The bubbles from 6 and the sludge from the raw water inflow pipe 8 contact and mix in the water pipe 15 and rise with increasing buoyancy. At the same time, the sewage in the water pipe 15 floats as a whole, and sinks through the upper end of the water pipe 15 with the air lift action, and the flow of water in the polluted water tank 3 changes, and the sewage sludge becomes the center of the buoyant sludge. However, it can sufficiently cope with settling sludge. Instead of providing the air diffuser 16, a method of directly injecting air into the raw water inflow pipe and mixing the air may be used.

[0007]

According to the present invention, it is possible to deal with qualitative changes in sludge, sedimentation due to the specific gravity, and floating sludge, without deteriorating the characteristics of the original gravity type thickening tank. That is, it is possible to receive the inflow sludge as a simple and energy-saving system. It also has a wide adaptation range for fluctuations in inflow.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an up-down flow enrichment tank.

[Explanation of symbols]

 1 is a concentration tank 2, a partition cylinder 3, a polluted water tank 4, a partition cylinder part 5, a floating sludge discharge plate 6, a separation water tank 7, a separated liquid channel 8, a raw water inflow pipe 9, an air pipe 10, floor panel 11, scraper 12, sludge pit 13, sludge transfer pipe 15, water pipe 16, diffuser pipe 17, drive device 18, drive shaft 20, floating sludge scraper 21, floating Sludge channel 22 is a bridge

Claims (2)

[Claims] 1. Sludge settling from inflow sludge is transferred to a floor (1).
0) and the sludge pit (1) with the scraper (11).
In a gravity-type downward-flow circular concentrating tank for collecting and discharging the separated liquid from the separated liquid channel (7), the partition cylinder (2), the partition cone (4), and the floating sludge discharge plate (5) ) Is provided to divide the tank into a polluted water tank (3) and a separated water tank (6). In the polluted water tank (3), the settled sludge is transferred to the lower floor, and the contaminants floating up are transferred to the water pipe (15) and the partitioning cylindrical cone ( 4) An up-down flow thickening tank characterized in that the sludge is discharged from the sludge channel (21) by the floating sludge discharge plate (5) and the floating sludge scraper (20) through the inside. 2. The up-down flow in the up-down flow enrichment tank according to claim 1, wherein a diffuser pipe (16) is provided in the water pipe (15) and connected to the air pipe (9) to diffuse air. Thickening tank.