JP3123897B2 - Sewage filtration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a sewage filtration apparatus for removing suspended solids such as suspended solids floating in raw water such as sewage and drainage, and more particularly to an improvement in the efficiency of removing suspended substances. The present invention relates to a sewage filtration apparatus which is excellent and which can reduce the frequency of backwashing and the time required for backwashing.

[0002]

2. Description of the Related Art In recent years, in the treatment of sewage such as sewage and drainage, the necessity of improving the quality of discharged water and effectively using treated water has been increasing, and various technological developments have been promoted. In other words, the quality of the influent water has a significant effect on the load on the raw water treatment reaction tank, so it is extremely important to remove suspended solids such as suspended solids floating in the raw water as the primary treatment of the raw water. is there.

Conventionally, a downflow type sewage filtration apparatus (conventional example 1) as shown in FIG. 5 of a schematic configuration explanatory view has been used to remove suspended substances in raw water. Less than,
The sewage filtration device 1 will be described with reference to the figure. Reference numeral 2 denotes a filtration device main body. In the filtration device main body 2, an upper filtration layer 3 filled with anthracite and sand are sequentially arranged from the upper side. A filled lower filter layer 4 is provided, and a filter medium support layer 5 for supporting the upper filter layer 3 and the lower filter layer 4 is provided below the lower filter layer 4. The raw water W _{0 in the} raw water tank 6 is used as the raw water pump P
_The water is pumped by the drive of ₀ , and flows into the raw water inflow portion 1a formed above the upper filtration layer 3 of the filtration device main body 2 through the raw water supply pipe 7. Then, the filtered water W ₁ from which suspended matter has been removed by passing through the upper filtration layer 3 and the lower filtration layer 4.
Accumulates in the filtered water reservoir 1b formed below the filter medium support layer 5 of the filtration device main body 2 and is stored in the filtered water storage tank 9 through the filtered water discharge pipe 8. If the amount of suspended solids captured by the filtration layers 3 and 4 increases due to the continuation of filtration, the filtration capacity decreases. Therefore, to Soraarai the filter layer, filter bed by supplying air to the backwashing air supply pipe 11 filtered water reservoir inside 1b through the drive of the backwash blower B, by driving the backwash pump P ₁ after Soraarai supplying filtered water W ₁ in the filtered water storage tank 9 to the filtered water reservoir portion 1b through the backwash water supply pipe 10. And
Filtered water W ₁ in the reverse pass is from the lower filter layer 4 into the upper filtration layer 3 is wash the filter layer 3 and 4. The pipe denoted by reference numeral 12 is a backwash water discharge pipe for returning backwash water accumulated in the raw water inflow section 1a during backwash to a not-shown sewage storage tank.

However, in the downflow type sewage filtration apparatus having this configuration, as described above, since anthracite or sand is used as the filter medium for the filtration layers 3 and 4, the filtration layers 3 and The suspended matter accumulates on the surface of No. 4 and becomes a so-called surface filtration state, so that filtration by the internal passage of the filtration layers 3 and 4 is not performed. Therefore, frequent washing and backwashing (the time required for backwashing is 30 to 60 minutes) must be performed.
There was a problem to be solved that the filtration efficiency of raw water was extremely poor. A sewage filtration apparatus capable of improving the filtration efficiency is disclosed in, for example, JP-A-4-300605 and JP-B-5-20126.

First, a sewage filter (conventional example 2) disclosed in Japanese Patent Application Laid-Open No. Hei 4-300605 will be described with reference to FIG. The floating filter medium particles 13 and 14 which float in the filtration tower 10 and are pressed by the net members 11 and 12 are mainly small-diameter floating filter medium particles which are arranged near the net member and have a high floating speed. 13 and other floating filter medium particles 14 mainly arranged below the floating filter medium particles 13 and having a larger diameter than the floating filter medium particles and a lower floating speed. , 14
Then, the raw water pump 6 is driven to drive the raw water tank 1 so as to capture the suspended matter in the raw water, which is the water to be treated, which is supplied near the bottom of the filtration tower 10, thereby filtering the filtered water. Is discharged to the treated water tank 18 via the

FIG. 7 (a) is a schematic structural explanatory view of a wastewater filtration device (conventional example 3) disclosed in Japanese Patent Publication No. Hei 5-20126, and FIG. 7 (b) is an enlarged view of a floating filter medium layer. ), A floating filter medium layer 3 made of a filter medium described below is provided below a wire mesh 2 provided inside the wastewater filtration device 1.
Are formed. A treated water discharge pipe 4 and a wash water supply pipe 5 are connected to an upper part of the waste water filtration device 1, and a wash water discharge pipe 6 is connected to a lower part of the waste water filtration apparatus 1. A treated water supply pipe 7 is connected to the middle of the apparatus 1. The filter medium of the floating filter medium layer 3 is shown in FIG.
As shown in (b), it is formed in a mesh cylindrical body, and both ends are open. The specific gravity of this filter medium is 0.9,
The porosity at the time of filling is 95%.

[0007] Accordingly, when the water to be treated containing suspended substances is supplied to the wastewater filtration device 1 through the water supply pipe 7, the suspended particles having a high sedimentation velocity are sedimented and removed in the sedimentation zone. The treated water from which the suspended particles have been removed passes through the floating filter medium layer 3 as an upward flow, at which time the remaining suspended solids adhere to the filter medium and are filtered. That is, since both ends of the mesh cylindrical body are open, a vortex is generated due to a speed difference between the flow rate of the treated water passing through the open end and the flow rate passing through the mesh.
Then, since the local area of the treated water is generated by the vortex, the suspended matter in the treated water is aggregated, and the aggregated suspended substance is captured by the mesh-like cylindrical body on the downstream side of the local accumulated area. In addition, since the local retention area is generated over the entire area of the filter medium layer, the trapping rate of suspended solids is high, and the filtration duration is long, so that the filtration efficiency is excellent.

[0008]

Problems to be Solved by the Invention
No. 5 and Japanese Patent Publication No. 5-201226 each disclose a filter for filtering waste water or waste water according to the above-mentioned conventional example. However, the former Japanese Patent Laid-Open No.
In the sewage filtration device disclosed in Japanese Patent No. 300605, since the surface area of each filter medium particle is small and the porosity of the filtration layer cannot be increased due to the use of the particulate filter medium, the ability to capture suspended solids should be increased. Can not.
Therefore, the frequency of backwashing cannot be reduced so much, and the improvement of filtration efficiency has not always been sufficient.

On the other hand, in the latter wastewater filtration device disclosed in Japanese Patent Publication No. Hei 5-201226, hair and fibrous suspended matter are easily entangled in the network of the floating filter medium layer, and are not easily removed when entangled. Even if the porosity of the filter media is large and the frequency of backwashing is low, if backwashing takes a long time or if it is entangled firmly, it cannot be discharged by backwashing, so it will remain entangled for a long time As a result, not only the improvement of the filtration efficiency is not always sufficient, but also the filtration efficiency gradually decreases. further,
When filtering raw water containing high concentrations of suspended solids, it is necessary to increase the thickness of the floating filter medium layer in order to remove suspended solids without causing surface filtration, which increases equipment costs. You.

Accordingly, it is an object of the present invention to provide a high-efficiency sewage filtration system capable of efficiently removing irrespective of the form of suspended matter, reducing the frequency of backwashing, and shortening the backwashing time. In providing the device.

[0011]

Means for Solving the Problems To solve the above problems, the means adopted by the sewage filtration apparatus according to the first aspect of the present invention is to pass raw water such as sewage and drainage from the upper side to the lower side. In a sewage filtration device having a filtration layer for separating suspended substances floating in raw water, the filtration layer is formed by at least two layers.
And a filter medium having a shape in which a plurality of small cylinders are integrally formed in parallel in the upper filtration layer , and having a specific gravity of 1.05 to 1.15.
And multiple small cylinders parallel to the lower filtration layer
A shape which is integrally formed on, a specific gravity met 1.3 to 1.5
Te, and it is characterized in that the filled filter medium of the small size <br/> than filter media filled in the upper filtering layer.

[0012] The means adopted by the sewage filtration apparatus according to claim 2 of the present invention comprises a filtration layer for passing raw water such as sewage or drainage from the lower side to the upper side and separating suspended substances floating in the raw water. A sewage filtration apparatus having at least two filtration layers, wherein the upper filtration layer has a shape in which a plurality of small cylinders are integrally formed in parallel, and has a specific gravity of 1.05 to 1.1.
5 and a plurality of small cylinders are integrally formed in the lower filtration layer in parallel with a specific gravity of 1.3 to 1.5.
And more than the filter medium filled in the upper filtration layer
Is characterized in that the filled filter medium of a large size.

[0013] The means adopted by the sewage filtration apparatus according to claim 3 of the present invention is the means according to any one of claims 1 and 2.
In the sewage filtration apparatus according to the item, a plurality of small filter media
From one end of these small cylinders to the other end,
It is characterized in that a gap which opens outwardly contiguous to the side.

[0014]

The sewage filter according to claim 1 or 2 of the present invention.
According to, a plurality of small cylinders that Hama charging the upper and lower filtering layer Rights
Each of a plurality of small cylinders of filter
By setting the inner diameter, the porosity of the filtration layer can be increased.
Therefore, even if suspended solids are captured by passage of raw water, surface filtration
Is not in a state, and large floating with large filter media
The substance and the small suspended solids are captured by small filter media, respectively.
Can be Also, when backwashing, air bubbles
Entangles and flows, but the ratio of the filter media filled in the upper filtration layer
A filter having a weight of 1.05 to 1.15 and filling the lower filtration layer.
Since the specific gravity of the material is 1.3 to 1.5, it is filtered by back washing.
Settling speed due to difference in specific gravity of filter media after backwashing even if media flows
The upper filtration layer and the lower filtration layer are formed again by the difference in the degree
And the filter medium of the upper filtration layer and the filter medium of the upper filtration layer are mixed.
There is no such thing.

According to a third aspect of the present invention, there is provided a sewage filtration apparatus.
If this is the case, these small
A gap that opens outward from one end to the other end of the cylinder
Is provided, so that the outer dimensions of the filter media are the same
Has a higher porosity than filter media without such gaps
Can be

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a sewage filtration apparatus according to Embodiment 1 of the present invention.
And FIG. 1A of a schematic configuration explanatory view showing the whole thereof,
FIGS. 1B and 1 are perspective views of a filter medium forming a filtration layer.
(C), filtration duration (unit: min) and head loss
(Unit: cmAq) and FIG.
Time (unit: min) and amount of suspended solids (unit: mg / liter)
And FIG.
Same as the first example and the same with the same function
This will be described with reference numerals.

Reference numeral 1 shown in FIG . 1 (a) is a downflow type sewage.
Reference numeral 2 denotes a filtration device, and reference numeral 2 denotes a filtration device main body. This filter
The specific gravity is 1.05 to 1.15, which will be described later, in the main body 2.
Filter layer 3 filled with a filter medium 3a having a desired shape and size
And a filter medium 4 having a specific gravity of 1.3 to 1.5 and having a shape and dimensions described below.
and a lower filtration layer 4 filled with a.
The upper filtration layer 3 and the lower filtration layer
4 is provided. Filtration source
The raw filtered water W ₀ in the water tank 6 is used to drive the raw filtered water pump P ₀ .
From the filtration device main body 2 through the raw water supply pipe 7.
In the raw water inflow section 1a formed above the upper filtration layer 3
Inflow.

Passing through the upper filtration layer 3 and the lower filtration layer 4
Filtered water W ₁ filtration device suspended solids have been removed by
Filtered water formed below the filter medium support member 5 of the main body 2
While collecting in the reservoir 1b, the filtered water is discharged through the filtered water discharge pipe 8.
The water is stored in the storage tank 9. By continuing the filtration, the upper and lower filtration
If the amount of suspended solids captured by the upper layers 3 and 4 increases,
Ability decreases. Therefore, by driving the backwashing blower B
Air is introduced into the filtered water reservoir 1b through the backwash air supply pipe 11.
Supply and clean the filter medium, and after performing the empty wash,
The backwash water supply pipe 10 is driven by the water pump P ₀ (P ₁ ).
The filtered raw water W ₀ in the filtered raw water tank 6 is filtered through the filtered water reservoir 1b.
Supply within. Then, the filtered raw water W _{0 is transferred} to the lower filtration layer 4.
To the upper and lower filtration layers
The upper layers 3, 4 are being washed. Suspended substances separated from filter media
Wastewater containing a large amount of water is discharged from the backwash water discharge pipe 12 to the outside of the system.
Will be issued.

By the way, the upper filtration layer 3 and the lower filtration layer 4
The specific gravity of the filter media 3a and 4a to be filled into
What was specified is that if it is less than 1.05, bubbles are generated by backwashing.
The filter media 3a and 4a float up due to the entanglement (the filtration layer flows by floating)
And there is a problem that filtration performance is reduced)
If it exceeds 1.5, the capacity of the backwash blower must be increased.
The initial cost and cost of the sewage filtration device 1
This increases the finning cost, and the filter media 3a, 4
Regarding the specific gravity difference of a, the specific gravity difference of 0.15 to 0.45
If they are not attached, they will be mixed with each other to form a large filter medium 3a.
Upper filter layer 3 and lower filter layer 4 consisting only of small filter medium 3a
Is impossible to maintain.

Next, a filter for filling the upper and lower filtration layers 3 and 4 is used.
The shapes and dimensions of the materials 3a and 4a are shown in FIGS. 1B and 1C.
This will be described with reference to FIGS. The filter media shown in FIG.
The filter medium shown in FIG.
It is. Type 1 filter media 3a and 4a are shown in FIG.
In Suyo, multiple parallel one body the small cylinders of (in this example 3)
In the formed shape, on the outer wall of each of the three small cylinders,
Open from one end to the other end of the small cylinder
A gap t is provided. The filter media 3a and 4a have a high density
A long body manufactured by extruding polyethylene
The filter media 3a, 4a
The outer diameter D and length L of the cylinder are set as follows, respectively.
ing. In particular, it is necessary to use high-density polyethylene.
Without any resin that can ensure the specific gravity of the above range,
For example, use acrylic, polyester, nylon, etc.
be able to.

A place for filtering raw water containing a high concentration of suspended solids
In the case, first, the filter medium 3a of the type 1 to be filled in the upper filtration layer 3
The outer diameter D and length L of the small cylinder are 12 to 20 mm,
Outer diameter of small cylinder of type 1 filter medium 4a filled in filter layer 4
D and length L are 3 to 8 mm. In addition, filter medium 3 of type 2
The outer diameter D and the length L of the small cylinders a and 4a are in the form of Type 1.
The same shape and size as those of the filter media 3a and 4a
The shape is such that no gap t is provided in the cylinder.

Small cylinder of filter medium 3a to be filled in upper filtration layer 3
The outer diameter D and the length L of the lower filtration layer 4 are 12 to 20 mm.
The outer diameter D and length L of the small cylinder of the filter medium 4a to be filled into
First, the upper filter layer 3 is provided outside the filter medium 3a.
If the diameter D and length L exceed 20mm, the lower filtration
Suspended substances leak to the layer 4 and the filtration resistance of the lower filtration layer 4
Increases the head loss and shortens the duration of filtration.
When the size is less than 12 mm, the upper filtration layer 3
Large amounts of suspended solids accumulate on the surface layer, a form of so-called surface filtration.
State, the head loss increases due to the increase in filtration resistance of the surface layer,
This is because the duration becomes shorter. Next, the bottom
If the size of the filtration layer 4 exceeds 8 mm, suspended solids are filtered.
Leaks to the water reservoir 1b and the filtration efficiency of suspended matter is 40
% Or less, the raw water treatment performance deteriorates,
When the size is set, a large amount of suspended solids will accumulate on the surface layer of the lower filtration layer 4.
The filtration duration increases in a short time due to the increase in filtration resistance of the surface layer.
Because it becomes.

The operation of the sewage filtration apparatus 1 will be described.
When, in due Ri filtering the raw water tank 6 to drive the filtration raw water pump P ₀
The filtered raw water W ₀ is supplied to the filtration device main body 2 through the raw water supply pipe 7.
When supplied to the raw water inflow section 1a, it is supplied to the raw water inflow section 1a.
The filtered raw water W ₀ is between the filter media 3 a of the upper filtration layer 3.
Large suspended solids in the hollow part of
Small floating material between the filter media 4a and the hollow portion of the small cylinder
Quality is trapped and the filtered water accumulates in the filtered water reservoir 1b.
Is discharged from the filtered water reservoir 1b via the filtered water discharge pipe 8.
It is. In such a filtration of raw water, according to the present embodiment,
The sewage filtration apparatus 1 is shown in Table 1 and FIG.
With a filtration layer filled with sand and anthracite
A filtration device according to Conventional Example 1 is indicated by a black circle and a solid line. )
As shown in the above, this example has a long filtration duration, and
It turned out that the filtration performance was extremely excellent.

[0024]

[Table 1]

According to Table 1 and FIG.
Head loss is reduced to 100 cmAq by continuing filtration for 50 min.
In this embodiment, the continuation of filtration becomes impossible due to
Then, even after 300 min, it is still 50 cmAq.
It resulted say that it is possible to continue the over. This
It is an example that enables continuous filtration for a long time.
Compared to sand and anthracite,
Thus, the porosity (about 70%) of the filter media 3a and 4a according to the present embodiment.
%) And the ability to trap suspended solids in the filtration layer is high.
It can be understood that it is caused by the criterion.

Next, type 1 and type 2 filter media 3a, 4a
Was tested for filtration performance. The results are shown in Tables 2 and 3 and FIG.
As shown. Table 2 shows that the upper filtration layer 3 has the format 1
The filter medium 3a to be formed into the shape of the type 1 in the lower filtration layer 4
Table 3 shows the upper filtration layer.
The filter medium 3a having the shape of the type 2 is formed on the lower
This is the case where the filter medium 4a having the shape of Expression 2 is filled. Ma
FIG. 3 shows the case of the filter media 3a and 4a having the shape of the type 1.
White square and solid line (for raw water) and black square (for filtered water
Filter media 3a, 4a having the shape of type 2
The white triangle and the solid line (for raw water) and the black triangle and the solid
This is indicated by a line (in the case of filtered water) .

[0027]

[Table 2]

[0028]

[Table 3]

According to Tables 2 and 3 and FIG. 3, the raw water was filtered.
The filtration duration is 300 min.
In the filter media 3a and 4a, the removal rate of suspended substances is 77 to 81%.
In the type 2 filter media 3a and 4a, the removal of suspended solids
The removal rate is 58-68%, and all show excellent removal rates.
ing. It should be noted that the type 1 filter media 3a and 4a
The removal rate of suspended solids is better than that of the filter media 3a and 4a.
Indicates that there is a gap t in the small cylinder of the filter media 3a and 4a of type 1.
Therefore, the porosity is larger than that of the type 2 filter media 3a and 4a.
Can be understood. Then, the conventional example 2 (special feature)
Wastewater filtration disclosed in Kaihei 4-300605
Porosity is higher than that of the filter layer filled with particulate filter media
Large, so that the ability to capture suspended solids is
Less frequent washing is required.

By continuing the filtration of the raw water, the filter medium 3
a, 4a, the amount of suspended matter trapped increases,
Since the filtration performance of the partial filtration layers 3 and 4 decreases, the filter media 3a,
In order to restore the filtration performance of 4a, the trapped floating
Backwashing is performed to remove substances from the filter media 3a, 4a.
You. When backwashing, fill the upper filtration layer 3 as described above.
The specific gravity of the filter medium 3a to be used is 1.05 to 1.15,
The specific gravity of the filter medium 4a to be filled in the lower filtration layer 4 is 1.3 to
1.5, so a large capacity backwashing blower B
By the backwashing by driving, these filter media 3a, 4a
It flows due to entanglement and collides with each other, so it is captured
Suspended material is easily separated from the filter media 3a, 4a and removed.
You.

That is, the filter medium 3a. 4a
Is disclosed in Conventional Example 3 (Japanese Patent Publication No. 5-201226).
Sewage filtration device)
Therefore, even if the suspended substance is hair or fibrous, it is 15 to 3
Backwash time of 0 min (30-60 min in Conventional Example 1)
Thus, it could be easily removed from the filter media 3a, 4a. Obedience
Therefore, the filtration performance of the upper and lower filtration layers 3 and 4 is surely in the initial state.
And the suspended matter is not removed as in Conventional Example 3.
As the quality continues to adhere, the filtration efficiency gradually increases
Does not decrease.

In this embodiment, the shape of the format 1 is used.
Filter media 3a and 4a have the shape of type 2.
a, 4a, the backwash can be completed in a shorter time,
It was found that the washing time was excellent. This means
It is provided in the small cylinder of the filter media 3a, 4a that has the shape of type 1.
The gap t contributes to the release of hair and fibrous suspended solids
Can be understood.

A sewage filtration apparatus according to Embodiment 2 of the present invention
This will be described with reference to FIG.
And the sewage filtration apparatus 1 drives the raw water pump P ₀ for filtration.
To supply raw water from the lower side of the filtration device main body 2,
The filtered water is discharged from a filtered water discharge pipe 8 provided on the upper side of the installation main body 2.
It is intended to be issued. And the filtration device body 2
The outer diameter D and length L of the small cylinder are provided on the lower filtration layer 4 on the bottom side of
Is 12 to 20 mm and the specific gravity is 1.3 to 1.5
While the filter medium 4 is filled,
The outer diameter D and the length L of the small cylinder in the upper filtration layer 3 are 3 to 8 mm.
And the filter medium 3 having a specific gravity of 1.05 to 1.15 is filled.
Have been packed.

Therefore, by driving the raw water pump P ₀ for filtration,
Raw water supplied from the lower side of the filtration device main body 2
Large suspended solids are removed by the large filter media 4a of the filter layer 4.
The small filtration material 3a of the upper filtration layer 3 removes small suspended solids.
Removed. The filter medium 4a of the lower filtration layer 4 has a large specific gravity.
Since the filter medium 3a of the upper filtration layer 3 has a small specific gravity,
The application is the same as in the first embodiment.

A sewage filtration apparatus according to Embodiment 3 of the present invention (see FIG.
(Not shown), the sewage filtration apparatus according to the first embodiment will be described.
To the filtration device body of the downward-flow type sewage filtration device
Weight is 1.05 to 1.5 and outer diameter D and length of small cylinder
A filter medium having a length L of 15 mm (the type 1 type described in the first embodiment)
It becomes something. ), Layer thickness 1000 m
m is provided with a single filtration layer. Soshi
Of the suspended solids of the sewage filtration apparatus according to the present embodiment.
In order to confirm the performance, this example and the above-mentioned Example 1 (upper filter) were used.
Overlayer thickness: 700 mm, lower filtration layer thickness: 300 m
m) and the removal rate (%) of suspended solids with the sewage filtration device
Was measured under conditions of a filtration speed of 400 m / day. So
Are as shown in Table 4.

[0036]

[Table 4]

According to the results shown in Table 4 above, in this embodiment,
The removal rate of suspended solids of the present wastewater filtration device is 52.4%.
Inferior to that of Example 1, but relatively superior
It turns out that there is. And the shape of the filter medium is
Type 1 with the described gap
Since the specific gravity of the material is 1.05 to 1.5,
There is an operation and an effect equivalent to those of the above embodiment.

In the above, the filter medium 3 having three small cylinders
Although the examples of a and 4a have been described, there is no particular need for three.
Alternatively, the number of small cylinders may be four or more. Small cylinder like this
The reason why the number of filters is set to 3 is that when each filter
In particular, the leakage of suspended solids can be reduced.
In the above, the case where the number of filtration layers is two and one is described.
As described above, between the filter media to be filled in each filter layer is 0.15 to
If a specific gravity difference of 0.45 is provided, three or more filtration layers will be used.
It is possible. However, it is filled in the lowermost filtration layer
Since the specific gravity of the filter media increases, the backwash blower has a large capacity.
There is a need to.

[0039]

As described above, according to claim 1 of the present invention,
Or 2 according to the sewage filtration device according to the present invention.
The filter medium has a shape in which a plurality of small cylinders are integrally formed in parallel.
For this reason, the porosity is set to be larger than in the conventional examples 1 and 2.
It has excellent removal performance of suspended solids,
Does not enter the surface filtration state and the frequency of backwashing is reduced
You. On the other hand, the porosity of the filter medium is smaller than that of Conventional Example 3.
However, like a mesh cylinder, hair and fibrous suspended solids
The time required for backwashing is short because the shape is not tightly entangled
Hair and fiber as filter media without being removed
Repeated backwashing as little suspended solids remain
May cause the filtration performance of the filtration layer to gradually decrease
Absent. Further, according to the sewage filtration device according to claim 3,
The porosity of the filtration layer is reduced by the gap provided in the small cylinder of the filter medium.
To increase the amount of suspended solids.
Improved capture performance and further reduction of backwash frequency
Has a great effect.

[Brief description of the drawings]

FIG. 1 (a) is a schematic configuration explanatory view showing the entire sewage filtration apparatus according to Embodiment 1 of the present invention, and FIGS. 1 (b) and 1;
(C) is a perspective view of a filter medium forming a filtration layer.

FIG. 2 is a diagram illustrating the relationship between the filtration duration (unit: min) and the head loss (unit: cmAq) according to Example 1 of the present invention.

FIG. 3 is an explanatory diagram of a relationship between a filtration continuation time (unit: min) and an amount of suspended solids (unit; mg / liter) according to the first embodiment of the present invention.

FIG. 4 is a schematic configuration explanatory view of a sewage filtration apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a schematic structural explanatory view of a downflow type sewage filtration device according to Conventional Example 1.

FIG. 6 is a schematic structural explanatory view of a wastewater filtration device according to Conventional Example 2.

7 (a) is a schematic structural explanatory view of a sewage filtration apparatus, and FIG. 7 (b) is an enlarged view of a floating filter medium layer according to Conventional Example 3. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sewage filtration apparatus, 1a ... Raw water inflow part, 1b ... Filtration water storage part 2 ... Filtration apparatus main body 3 ... Upper filtration layer, 3a ... Filter medium 4 ... Lower filtration layer, 4a ... Filter medium 5 ... Filter medium support layer 6 ... Filtration raw water tank 7 ... raw water supply pipe 8 ... filtered water discharge pipe 9 ... filtered water reservoir 10 ... backwash water supply pipe 11 ... backwash air supply pipe 12 ... backwash water discharge pipe B ... backwash blower P ₀ ... filtered raw water pump P ₁ : Backwashing pump t: Gap provided in a small cylinder of filter medium W ₀ : Raw water for filtration W ₁ : Filtration water

Continuation of front page (72) Inventor Akira Ishiyama 1-3-18 Wakihama-cho, Chuo-ku, Kobe-shi, Hyogo Kobe Steel, Ltd. Kobe Head Office (56) References JP-A-5-208104 (JP, A) Special 58-45793 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 24/02-24/26

Claims (3)

(57) [Claims] 1. A sewage filtration apparatus having a filtration layer for passing raw water such as sewage and drainage from the upper side to the lower side and separating suspended substances floating in the raw water, wherein the filtration layer is reduced in number.
The upper filtration layer has a shape in which a plurality of small cylinders are integrally formed in parallel, and has a specific gravity of 1.05 to 1.1.
And 5 small circles in the lower filtration layer
The tube is integrally formed in parallel and has a specific gravity of 1.3 to 1.5.
And more than the filter medium filled in the upper filtration layer
A sewage filtration device characterized by being filled with a small-sized filter medium. 2. A sewage filtration apparatus having a filtration layer for passing raw water such as sewage or drainage from the lower side to the upper side and separating suspended substances floating in the raw water, wherein the filtration layer is reduced. Each of the upper filtration layers has a shape in which a plurality of small cylinders are integrally formed in parallel, and has a specific gravity of 1.05 to 1.1.
5 and a plurality of small cylinders are integrally formed in the lower filtration layer in parallel with a specific gravity of 1.3 to 1.5.
And more than the filter medium filled in the upper filtration layer
A sewage filtration device characterized by being filled with a large-sized filter medium. 3. The outer wall of each of the plurality of small cylinders of the filter medium.
To the outside that continues from one end to the other end of these small cylinders.
Claim, characterized in that a clearance opening to 1 or
The sewage filtration device according to any one of the items 2 to 5 .