JPS62163797A - Anaerobic treating device - Google Patents

Abstract

PURPOSE:To prevent the generation of scum and the leakage of SS into treated water and to sufficiently return sludge by regulating the gas pressure of a gas collecting chamber to maintain the inflow into a solid-liq. separation part at a specified value, and preventing the deposition of sludge at the solid-liq. separation part. CONSTITUTION:In the anaerobic treating device, especially a sludge blanket type device, the first partition plate 3 inclined at an angle of about 45 deg. from one side on the liq. level and the second partition plate 4 crossing the plate 3 on the opposite side are provided at the upper part of a digestor vessel 1, and a sludge passage 5 is formed at the lower part. A solid-liq. separation part 6 is formed at the upper part of the digestion vessel 1 with the partition plates 3 and 4, a digestion part 7 is furnished at the lower part, the gas collecting chamber 15 is provided in an ascending passage 13 on the wall surface side of the partition plate 4, and the gas pressure is regulated by a regulating means. Consequently, the liq. level is controlled, the separability at the solid-liq. separation part 6 is improved, sludge is not deposited, scum is not generated, and the leakage of SS into treated water is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an anaerobic treatment device used for water treatment etc., and particularly to a sludge blanket type anaerobic treatment device.

[Conventional technology]

Sludge blanket type anaerobic treatment equipment forms a sludge blanket using sludge mainly composed of anaerobic bacteria and brings it into contact with waste liquid to perform anaerobic digestion.
The gas generated by the digestion rises and disturbs the sludge blanketer 1, making it impossible to perform solid-liquid separation, so the digestion reaction section and the solid-liquid separation section are separated. As such a digester, there is one in which a solid-liquid separation section is partitioned into an inverted triangular cross section by two walls having an inclination of about 45 degrees, and an IJ plate (USP No. 4253956).

[Problem that the invention seeks to solve]

However, in this device, the sludge in the solid-liquid separation section flows into the digestion reaction section through natural sedimentation, so if the properties of the sludge deteriorate and the settling properties become poor, the return of the sludge will be insufficient. Sludge accumulation and scum occur in the solid-liquid separation section,
There was a problem when the machine could not operate according to the set load.

This invention is intended to solve the above-mentioned problems, and prevents the accumulation of sludge in the solid-liquid separation section, thereby preventing the generation of scum and leakage of SS into the treated water, as well as preventing the sludge from flowing into the digestion reaction section. The purpose is to provide an anaerobic treatment device that can be returned sufficiently.

[Means for solving problems]

This invention provides a digestion tank having a raw liquid inlet at the bottom, a first partition plate extending into the liquid at an angle from one side of the digestion tank, and an opposite side of the digestion tank at an angle intersecting the first partition plate. A second partition plate extending inclined from below the liquid level on the side and forming a sludge dε path between it and the first partition plate; a solid-liquid separation section formed at the top, a digestion reaction section formed at the bottom, and the second
a gas collection chamber that covers the upper part of the ascending flow path formed between the partition plate and the wall surface of the digester, and a liquid flow path that connects the lower part of this gas collection chamber to the solid-liquid separation section described in i'iiii. The anaerobic treatment apparatus is characterized in that it has a gas pressure adjusting means for adjusting the gas pressure in the gas collection chamber.

[For production]

In the anaerobic treatment apparatus of the present invention, when the liquid is introduced into the digestion tank and brought into contact with the sludge blanket in the digestion reaction section to perform anaerobic treatment, the gas generated rises up the ascending flow path and captures the gas. Collected in a collection room. At this time, part of the reaction liquid and sludge rises along with the gas through the ascending channel and flows from the lower part of the gas collection chamber through the liquid channel into the solid-liquid separation section. Here, the solid-liquid separated liquid is taken out as a processing liquid,
The sludge is returned to the digestion reaction section from the sludge channel. The gas pressure adjustment means adjusts the gas pressure in the gas collection chamber and the flow rate of liquid and sludge entering the solid-liquid separation section, improving separation performance in the solid-liquid separation section, eliminating sludge accumulation, and reducing scum. This eliminates the occurrence of SS leakage into the treated water, and ensures sufficient sludge return.

〔Example〕

Hereinafter, the present invention will be explained with reference to embodiments of the drawings.

The drawing is a vertical sectional view of an anaerobic treatment apparatus according to an embodiment of the present invention.

In the drawing, 1 is a digestion tank consisting of a rectangular parallelepiped container;
Porous tubular stock solution inflow portions 2 are uniformly provided over the entire bottom surface. The upper part of digester 1 is located approximately 45 degrees above the liquid level on one side.
A first partition plate 3 is provided which extends into the liquid while being inclined at an angle of . In addition, a second partition plate 4 extends from below the liquid level on the opposite side at an angle of approximately 45° in a direction intersecting the partition plate 3.
is provided, and the lower part thereof forms a sludge channel 5 between the lower end portions of the partition plate 3.

A solid-liquid separation section 6 is formed in the second part of the digestion tank 1 by the partition plates 3 and 4, and a digestion reaction section 7 is formed in the lower part. A treatment liquid extraction groove 9 is formed by an overflow wall 8 in the upper part of the partition plate 3, and is connected to a treatment liquid pipe 10.A first groove 9 is formed between the treatment liquid extraction groove 9 and the digestion tank wall 1a. A gas collection chamber 11 is formed and communicates with a gas exhaust pipe 12.

An ascending channel 13 is formed between the partition plate 4 and the digester wall surface 1b. At the lower end of the partition plate 4, a third partition plate 14 inclined at an angle of about 15° in the direction intersecting the partition plate 4 extends toward the ascending flow path 13 side. Partition plate 14 and digester wall 1
The distances A and B from a and lb are A>8 (2:1 in the example)
).

The second gas collection chamber 15 covers the upper part of the ascending flow path 13.
A fourth partition plate 17 is provided at an angle so as to form a liquid flow path 16 communicating with the solid-liquid separation section 6 from the lower part thereof. Opposing the liquid flow path 16, pan full plays 1 to 18 are provided in the solid-liquid separation section 6 at positions below the liquid level that do not reach the partition plate 4.

Reference numeral 19 denotes a water seal tank as a gas pressure adjusting means, which communicates with the ascending passage 13 through a communication pipe 20, and has a gas discharge pipe 21 connected to its upper part. And the inner cylinder 22 whose lower part is open
is inserted from above the liquid level, and the insertion depth is adjusted using the handle 23! It is said that J construction is possible. Further, a gas discharge pipe 24 stands up within the inner cylinder 22 and communicates with the gas collection chamber 15 through a communication pipe 25 .

26 is a sludge blanket formed in the digestion reaction section 7, 27 is a raw solution pipe communicating with the raw solution inflow section 2, 28 is a sludge pit provided at the bottom of the digestion tank 1, and 29 is a sludge drain pipe.

In the above configuration, when the stock solution is supplied from the stock solution pipe 27 and allowed to flow into the digestion tank 1 from the stock solution inflow section 2 to perform anaerobic digestion, the stock solution mixes with the sludge forming the sludge blanket 26 in the digestion reaction section 7. The organic matter is mainly decomposed by the action of acid-producing bacteria to produce w1 acid, and further, the organic acid is decomposed by the action of methanogen-producing bacteria to produce methane.

A part of the gas generated as the digestion progresses in the digestion reaction section 7 is guided to the lower side of the first partition plate 3 and the third partition plate 14 and rises, and enters the first gas collection chamber 11. The gas is collected and discharged from the gas exhaust pipe 12.

The remainder of the gas is guided to the lower side of the second partition plate 4.

It ascends through the ascending channel 13 together with the reaction liquid and sludge.

The gas is collected in the second gas collection chamber 15. "Rising channel 13"
Since the amount of gas rising twice is determined by the distances A and B, it can be adjusted by the length of the partition plate 14. By setting A>B, it is possible to keep the total amount of gas for sludge circulation to 172 or less. desirable.

The reaction liquid and sludge rising along with the gas rising in the rising flow path 13 flow from the lower part of the gas collection chamber 15 through the liquid flow path 16 into the solid-liquid separation section 6 . And baffle play 1~
18, the reaction liquid passes above the baffle plate 18, enters the solid-liquid separation section 6, and undergoes solid-liquid separation. The sludge passes under the baffle plate 18, flows down along the partition plate 4, and circulates from the sludge channel 5 to the digestion reaction section 7 while preventing sludge accumulation. The liquid separated in the solid-liquid separator 6 is taken out from the processing liquid extraction groove 9 to the processing liquid pipe 10. Further, the settled sludge is returned to the digestion reaction section 7 together with the sludge circulating on the partition plate 4.

The flow rate Q flowing into the solid-liquid separator 6 from the ascending channel 13 is controlled by the gas collection chamber 15 by a water seal tank 19 which is a gas pressure adjusting means.
This maintains solid-liquid separation efficiency and circulation efficiency at a high flow rate, and prevents accumulation and scum in the solid-liquid separator 6 and S into the treated water.
S leak is prevented.

The gas pressure in the gas collection chamber 15 is adjusted by rotating the handle 23 to change the insertion depth of the inner cylinder 22, and at this time, the gas in the gas collection chamber 15 flows through the communication pipe 25 and the gas discharge. Pass through the pipe 24 and from the lower end of the inner cylinder 22 to the water seal tank 1.
When the gas is discharged into the gas chamber 9 and discharged from the gas discharge pipe 21, the gas pressure is adjusted 3 according to the difference between the liquid levels Q and L. Here, Q is the liquid level in the solid-liquid separation section 6, and 2 is the liquid level in the gas collection chamber 15 that corresponds to the tip of the inner cylinder 22, and the liquid level is adjusted within the range h.

In this way, the liquid level is adjusted by the gas pressure in the gas collection chamber 15, and when the gas pressure increases, the liquid level I decreases and the flow rate Q
When the gas pressure decreases and the gas pressure increases, the liquid level decreases and the flow rate Q increases. By maintaining the flows -1 and Q at appropriate values, the separation performance in the solid-liquid separation section 6 is improved, sludge accumulation is eliminated, and scum generation is eliminated.

SS leakage to treated water is eliminated and sludge is returned sufficiently.

According to the experimental results, when h = 300 + am, the SS in the treated water was 1000 to 2000 mg/Q when the gas pressure in the gas collection chamber 15 was Q ma + Aq, but about 250 m
It was reduced to 100 mg/Q by adjusting mAq.

Excess sludge is removed from the sludge pit 28 provided at the bottom of the digestion tank 1.
The sludge is concentrated and drained from the sludge pipe 29.

In the above description, the partition plate 14 may be provided separately from the partition plate 4, but by joining them as in the embodiment, short circuits of circulating sludge can be prevented and digestion can be performed efficiently. Further, although it is sufficient to simply provide a valve as the gas pressure adjustment means, the water seal tank 19 allows for easier and more accurate adjustment. The water seal tank 19 may be provided within the digestion tank 1, and in this case, the communication pipe 20 is omitted. Furthermore, the digestion tank 1 may be of a cylindrical shape with center 1a or lb.

The present invention can be used as an anaerobic treatment device for treating organic waste liquid, sewage sludge, human waste, and other raw solutions suitable for anaerobic digestion.

〔Effect of the invention〕

According to the present invention, since the gas pressure in the gas collection chamber is adjusted to maintain the flow rate to the solid-liquid separation section at a predetermined value,
It is possible to prevent the accumulation of sludge in the solid-liquid separation section, thereby preventing the generation of scum and leakage of SS into the treated water, and at the same time, it is possible to sufficiently return the sludge to the digestion reaction section.

[Brief explanation of drawings]

The drawing is a vertical sectional view of the embodiment, and 1 is a digestion tank. 2 is the stock solution inlet, 3, 4, 14.17 is the partition plate, 5
1 is a sludge channel, 6 is a solid-liquid separation section, 7 is a digestion reaction section, 11° 15 is a gas collection chamber, 13 is an ascending channel, 16 is a liquid channel, 1
8 is a baffle plate, and 19 is a water seal tank.

Claims (4)

[Claims] (1) A digestion tank having a raw liquid inlet at the bottom, a first partition plate extending into the liquid at an angle from one side of the digestion tank, and an opposite side of the digestion tank at an angle intersecting the first partition plate. a second partition plate that extends obliquely from below the liquid level and forms a sludge flow path between it and the first partition plate, and a second partition plate formed at the upper part of the digestion tank by the first and second partition plates. a gas collection chamber that covers the upper part of the ascending channel formed between the solid-liquid separation section and the digestion reaction section formed at the lower part, and the second partition plate and the wall surface of the digestion tank; and this gas collection chamber. An anaerobic processing apparatus characterized in that it has a liquid flow path communicating from a lower part of the unit to the solid-liquid separation section, and a gas pressure adjustment means for adjusting the gas pressure in the gas collection chamber. (2) The anaerobic treatment apparatus according to claim 1, wherein the gas pressure adjusting means is a water seal tank. (3) The anaerobic treatment apparatus according to claim 1 or 2, wherein the solid-liquid separation section has a baffle plate facing the liquid flow path and below the liquid surface that does not reach the second partition plate. (4) The anaerobic treatment apparatus according to any one of claims 1 to 3, wherein the second partition plate is joined to a third partition plate inclined in the opposite direction at the lower end thereof.