JPS6384693A - Fluidized bed type sewage treatment device - Google Patents

Abstract

PURPOSE:To stabilize the carrier fluidity condition in a tank in an early period by using stirring nozzles in the intermediate part of the tank and water spraying nozzles in the lower part of the tank by groups and making simultaneous parallel operation of many raw water pumps and circulating pumps transiently at the time of starting or restarting. CONSTITUTION:The carriers to which microorganisms are stuck are fluidized in the treatment tank 11 having a raw water inflow part 12 in the lower part, a treated water outflow part 29 in the upper part and a circulating water system 31 connecting the upper and lower parts, by which the org. matter in waste water is anaerobically treated and removed. Inflow water nozzles 14 are provided to the lower part of the treatment tank and the stirring nozzles 22 are disposed in the intermediate part of the treatment tank. The nozzles 14, 22 are further branched from a spraying water main pipe 16 through branch pipes 17, 24. Selector valves 18, 23 are interposed to the respective branch pipes branched from the main pipe 16 thereof. As a result, the satisfactory flow rates of the injection water are obtd. from the respective nozzles and the compacted carrier layers are fluidized discretely above and below, by which the carrier fluidity condition in the tank is stabilized in an early period.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a fluidized bed sewage treatment system for wastewater.ヱ)
It is possible to bring the microorganism-attached carrier into a stable fluid state at an early stage, and to maintain excellent processing capacity during normal operation. This is related to a sewage treatment device that can achieve the desired results.

``Prior art'' Recently, as shown in Fig. 6, wastewater to be treated is placed in a treatment tank 2 filled with fine particles (0.1 to 0.5 mm) of sand, activated carbon, zeolite, etc. as a block 1. The flow rate in the tank is increased by auxiliary means such as a circulation pump 3, and the carrier l is injected into the tank.
A fluidized bed sewage treatment method has been developed in which organic wastewater is treated by maintaining the carrier in a fluidized state and forming a microbial film on the surface of the carrier l to retain the microorganisms in the tank.

This treatment method has the advantage that a large amount of microorganisms can be retained in the treatment tank 2 because the surface area of the carrier 1 for attachment of microorganisms can be dramatically increased compared to other treatment methods. Its high performance is attracting attention, as it has the advantage of being less prone to problems such as clogging due to its fluid nature.

"Problems to be Solved by the Invention" In the fluidized bed sewage treatment method described above, it is preferable to make the carrier 1 into fine particles for the purpose of reducing the energy required to fluidize the carrier 1 during normal operation. Furthermore, although it is preferable to maintain a minimum fluidity state, depending on the operating conditions, the carrier l to which the microorganisms are attached may adsorb and coagulate, causing compaction and causing uneven flow. As a countermeasure, a stirring blade is rotated within the processing tank 2 to prevent consolidation, but such a countermeasure requires a complicated and large-scale device structure, and requires a lot of effort to rotate the stirring blade. This has the disadvantage of requiring a large amount of power.

In addition, in the fluidized bed sewage treatment method mentioned above, when the inflow water stops due to startup or an accident, the carrier l settles at the bottom of the treatment tank, and if this continues for a long time, it causes consolidation and prevents the start of operation. The problem was that there were even cases where it became impossible.

The present invention has been made in view of the above circumstances, and is a fluidized bed type device that has a simple device structure, can prevent the consolidation of carriers without requiring special power, and can easily make the consolidated carriers more dynamic. The purpose is to provide sewage treatment equipment.

[Means for Solving the Problems] In order to achieve the above object, the present invention introduces microorganisms into a treatment tank having a raw water inlet at the bottom, a treated water outlet at the top, and a circulating water system connecting the upper and lower parts. In a fluidized bed wastewater treatment device for treating and removing organic matter in wastewater in an anaerobic state by fluidizing the adhered carrier, an injection water nozzle is provided at the bottom of the treatment tank, and an injection water nozzle is provided at the middle of the treatment tank. The present invention is characterized in that stirring nozzles are provided, and these nozzles are arranged so as to be branched from the main injection water pipe via branch pipes, and each branch pipe branched from the main pipe is provided with a switching valve, respectively.

``Operation'' When starting up or restarting after a periodic inspection, by temporarily operating multiple circulation pumps and raw water pumps in parallel, and operating the switching valve, wastewater is first diverted from only the stirring nozzle located in the middle of the treatment tank. is injected, and then only from the injection water nozzle at the bottom of the tank. In this way, the waste water is strongly injected from each nozzle separately, thereby making it easier to make the compacted carrier in the treatment tank more active, and quickly achieving a carrier flow rate state in the treatment tank.

In addition, during normal operation, the flow rate effect of the carrier by injecting waste water from the injection water nozzle is combined with the agitating effect of the carrier by injecting waste water from the stirring nozzle.
It is possible to easily prevent uneven flow caused by adsorption and aggregation of microorganism-adhered carriers over the entire area of the processing tank.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of the entire apparatus, and reference numeral 11 in the figure is a processing tank. A raw water injection part 12 is provided at the bottom of the treatment tank 11, which is narrower than the upper or middle part, and there are supply pipes divided into multiple systems (three systems in the figure) as shown in Figure 2. 13a to 13c are provided. Injection water nozzles 14, which will be described later, are provided at predetermined intervals in these supply pipes.
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It is connected to the main pipe 16. Each supply pipe 13a=13c and a connecting pipe (branch pipe) that connects these supply pipes to the main pipe I6! A switching valve I8.19 is interposed in each case. Note that the reason why the raw water injection part 12 is made narrow as described above is to increase the flow rate of wastewater especially at the time of startup.

A ring pipe 2o is arranged on the outer periphery of the central part of the processing tank II,
The ring pipe 20 is provided with branch pipes 21 extending radially inward and penetrating the side wall of the processing tank 11 at predetermined intervals in the circumferential direction, and at the tips of the branch pipes 21 are provided stirring nozzles 22 to be described later.
is attached (see Figure 3). Among these stirring nozzles 22, every other nozzle is provided so as to face the center of the processing tank II, and the remaining nozzles 22 are inclined in the circumferential direction along the inner surface of the side wall of the processing tank 1. It is set up so that you can. Further, the ring pipe 20 is connected to a stirring connecting pipe (branch pipe) 24 in which a switching valve 23 is interposed.
The main pipe I6 is connected to the downstream side of the raw water pump I5.

The upper large diameter part of the processing tank 11 is
A partition wall 26 of P is provided, and the outside of the partition wall 26 is connected to the separation chamber 2.
7 is formed. There is an overflow weir 2 in the upper part of the separation chamber 27.
A treated water outflow section 29 partitioned by 8 is provided, and the treated water that accumulates there is discharged to the outside through an outflow pipe 30. Further, a circulating water pipe 31 is provided from inside the partition wall 26 to extend to the outside through the side wall of the processing tank 11, and the circulating water pipe 31 is connected to the main pipe 16, and a pump 32 is interposed therebetween. equipped. Note that a spare pump is provided for both the raw water pump 15 and the circulation pump 32.

Reference numeral 33 in FIG. 1 indicates an excess sewage withdrawal pipe provided at the lower inclined portion of the large diameter portion 25 of the treatment tank 11.

On the other hand, the nozzle 34 shown in FIG.
4 and the stirring nozzle 22, which has a check valve 36 in which a ball 35 is interposed near the upper end of the nozzle hole 34a, and a nozzle supported on the outer periphery via a stay 37. It has a ring 38. The wastewater passing through the nozzle hole 34a also attracts the wastewater existing inside the nozzle ring 38, and is injected into the tank as a flow with a large diameter at the upper end of the nozzle ring 38.

Further, the nozzle 40 shown in FIG. 5 is the injection water nozzle 1.
4, and is attached to the surface supply pipes 13a to 13c together with the nozzle 34 at an appropriate ratio. This nozzle 40 has a check valve 36 having a configuration similar to that shown in FIG. It has a guide 42. The waste water that has passed through the nozzle hole 40a is guided by the water flow direction guide 42 and is jetted downward.

Next, the operation of the fluidized bed type sewage treatment apparatus having the above configuration will be explained.

At startup or at restart after periodic inspection, a large number of raw water pumps 15 and circulation pumps 32, including backup ones, are temporarily operated in parallel to ensure the required amount of water to be injected.

First, the switching valve on the injection water nozzle 14 side! 9 is closed, and the switching valve 23 on the stirring nozzle 22 side is opened to inject waste water only from the stirring nozzle 22. This causes the upper part of the consolidated carrier layer deposited in the tank to expand and become dynamic.

Next, close the switching valve 23 and open the switching valve 19,
Waste water is injected only from the injection water nozzle 14 to make the lower part of the consolidated carrier layer dynamic. Moreover, at this time, the switching valve 18
... to supply wastewater to each of the three systems in which the injection water nozzle 14 is installed in sequence, and
To obtain a larger amount of water jetted from 4. Furthermore, since the upper side of the consolidated layer has already been activated at this time,
Activation of the lower consolidated layer is relatively easy.

In this way, the upper and lower compacted layers are individually activated to release the compacted state of the carrier.

On the other hand, during normal operation, the raw water pump 15 and the circulation pump 3
2 is activated, wastewater is distributed and inflowed from both injection water nozzles 14 arranged at the bottom of the treatment tank 11 to create an upward flow,
In addition to uniformly fluidizing the carrier, a stirring nozzle 2 disposed in the middle of the processing tank is used to stir and flow, thereby preventing uneven flow due to adsorption and compaction of the carrier.

In the above embodiment, the stirring nozzle 22 is provided in the middle part of the processing tank 11 in only one layer in the vertical direction, but the processing tank 1
Depending on the shape of the stirring nozzle 1, the stirring nozzles 22 may be provided in multiple layers.

"Effects of the Invention" As explained above, the present invention provides the following excellent effects.

■ At startup or restart, the stirring nozzle in the middle of the tank and the injection water nozzle in the bottom of the tank are used in groups, and by temporarily operating many raw water pumps and circulation pumps in parallel, it is possible to A sufficient amount of water can be obtained, and the upper and lower consolidated carrier layers can be activated separately, thereby making it possible to quickly stabilize the flow state of the carrier in the tank.

■ During normal operation, the fluidization of the carrier by the injection water from the injection water nozzle placed at the bottom of the tank and the fluidization of the carrier in the middle of the tank.
l-Ll 5 1 +-IA? II I
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1↓ 1 and 1-1-'F The stirring action of the carrier interacts with the carrier, and it is possible to easily prevent uneven flow in the tank caused by adsorption and agglomeration of the microbial adhering assembly.

■ In addition, since jet water is used for all fluidization and stirring, the mechanism is simple and the equipment can be simplified.

[Brief explanation of the drawing]

1 to 5 show one embodiment of the present invention, FIG. 1 is a schematic configuration diagram of the entire device, FIG. 2 is a view taken along the line ■-■ in FIG. 1, and FIG. ■-■ line arrow view, Figures 4 and 5 in the figure
The figure is a side sectional view showing an example of an injection water nozzle and an agitation nozzle, and FIG. 6 is a schematic configuration diagram showing a conventional example of a fluidized bed type sewage treatment apparatus. 11... Treatment tank, 12... Raw water inlet, 14... Injection water nozzle, 15... Raw water pump, 16... Main Tube, 17...
・Connecting pipe (branch pipe), 18.19.23...Switching valve, 20...Ring pipe, 22...Stirring nozzle, 24...Stirring Connecting pipe (branch pipe), 29.
... Treated water outflow section, 32 ... Circulation pump. Figure 1 0a

Claims (1)

[Claims] Organic matter in wastewater is kept in an anaerobic state by flowing carriers with microorganisms attached to the treatment tank, which has a raw water inlet at the bottom, a treated water outlet at the top, and a circulating water system that connects the upper and lower parts. In a fluidized bed type sewage treatment equipment for wastewater to be treated and removed, an injection water nozzle is provided at the bottom of the treatment tank, an agitation nozzle is provided at the middle of the treatment tank, and these nozzles are connected to the injection water main pipe through a branch pipe. A fluidized bed sewage treatment device characterized in that the pipes are arranged in a branched manner, and each branch pipe branched from the main pipe is provided with a switching valve.