JP2002239537A - Excess gas separation tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excess gas separation tank capable of effectively floating flocs. SOLUTION: The excess gas separation tank 27 is equipped with a hermetically sealed easing 28, which has a semispherical ceiling wall 28A and is formed into an almost cylindrical shape as a whole, and the jet pipe 29 vertically arranged in the casing 28 to communicate with a water guide pipe 26. Further, the excess gas separation tank 27 is constituted so that the opening part 29A of the jet pipe 29 is extended up to the vicinity of the ceiling wall 28A of the casing 28 and pressurized air dissolved water is forcibly discharged upwardly from the opening part 29A and the pressurized air dissolved water forcibly discharged from the opening part 29A impinges against the ceiling wall 28A to disperse and comes into contact with excess air to dissolve excess air in the pressurized air dissolved water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a surplus gas separation tank.

[0002]

2. Description of the Related Art In the fields of water treatment, wastewater treatment, sewage treatment and the like, as a method of removing suspended substances and colloidal substances, etc., present in water, generally, suspended substances and colloidal substances are aggregated. A method is known in which after forming aggregates, fine bubbles are adhered to these and floated on the water surface to perform solid-liquid separation.

FIG. 3 shows a schematic diagram of this example. In such a processing method, for example, air is dissolved in water in a pressurized state by a pressurizing pump 2 to generate pressurized air-dissolved water. Then, the pressurized air-dissolved water is depressurized by the pressure reducing valve 4 and then injected into the floating tank 1 for performing solid-liquid separation. At this time, when the pressurized air-dissolved water is depressurized to the atmospheric pressure by the pressure reducing valve 4, the air dissolved in the pressurized air-dissolved water is released and is generated as fine bubbles. This makes it possible to float and separate the aggregates. However, since the pressurized air-dissolved water obtained from the pressurized pump 2 contains surplus air that has not been dissolved in the pressurized air-dissolved water, it can be directly injected from the pressurized pump 2 into the floating tank 1. Since the excess air becomes large bubbles, which may hinder the attachment of the fine bubbles to the aggregates, a surplus gas separation tank that separates the excess air and the pressurized air dissolved water as a pre-step of injecting into the floating tank 1 No. 3 was once accumulated and excess air was removed.

[0004]

However, the conventional surplus gas separation tank merely separates surplus air (excess gas) and pressurized air dissolved water (pressurized gas solution). Even when air was not sufficiently dissolved in the compressed air dissolved water, it was only injected into the floating tank as it was.
However, it is desirable to dissolve air in the pressurized air-dissolved water to a saturated state at the temperature and the atmospheric pressure. The present invention has been completed based on the above circumstances,
It is an object of the present invention to provide a surplus gas separation tank capable of injecting a pressurized gas solution in which a gas is dissolved to a saturated state at the temperature and the atmospheric pressure into a floating tank and effectively floating aggregates.

[0005]

Means for Solving the Problems As means for achieving the above object, a first aspect of the present invention is a method of mixing a liquid and a gas in a pressurized state and dissolving the gas in the liquid. The pressurized gas solution is temporarily stored inside the sealed main body, and the excess gas that is not dissolved in the liquid among the mixed gases is separated above the level of the pressurized gas solution. A surplus gas separation tank, wherein the pressurized gas solution is dropped from the upper portion where the surplus gas is stored onto the surface of the pressurized gas solution stored in the main body. .

According to a second aspect of the present invention, in the first aspect, the ceiling wall of the main body is formed in a dome shape, and the insertion pipe for injecting the pressurized gas solution into the main body is provided. It is inserted into the main body, and the front end opening of the insertion tube is provided so as to face the ceiling wall, and the pressurized gas dissolved water jetted from the front end opening collides with the ceiling wall to be dispersed. However, it has features.

[0007]

<Operation and effect of the present invention><Invention of claim 1> Disturbing the level of the pressurized gas dissolving liquid stored in the main body of the surplus gas separation tank to take in the surplus gas and dissolve more gas A pressurized gaseous solution can be produced. Therefore, it is possible to generate more fine bubbles in the floating tank and to effectively float the aggregates.

<Invention of Claim 2> The pressurized gas solution stored in the main body is uniformly dispersed in the main body by colliding the pressurized gas solution injected from the opening at the tip with the ceiling wall. Since the surplus gas can be taken in over a wide range of the entire liquid surface, the surplus gas can be further dissolved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
A description will be given based on FIG. Reference numeral 10 denotes a floc forming tank, which undergoes, as a previous step, a step of adding a coagulant to the water to be treated containing impurities and performing rapid stirring to form fine aggregates. The floc forming tank 10 is a tank for agglomerating fine aggregates generated in the previous process to form flocs, and floating and collecting the flocs.

An inflow pipe 11 is connected to the upstream side surface of the floc forming tank 10, from which water to be treated containing fine aggregates as described above flows in under pressure.
Further, an outflow pipe 12 for discharging the treated water after the treatment of the impurities is connected to the downstream side surface on the opposite side.

The interior of the floc forming tank 10 is divided into a plurality of chambers a to h by a plurality of partition plates 13 arranged in parallel from the upstream side to the downstream side. Each partition plate 13 is arranged such that a gap is alternately provided on the opening edge side and the bottom side of the floc forming tank 10. Specifically, the uppermost chamber a is closed on the bottom side and a gap is held on the opening edge side, and the adjacent b chamber is closed on the opening edge side on the contrary,
A gap is provided on the bottom side, and the sequence is repeated in this order to reach the lowermost stream. Therefore, the water to be treated that has flowed into the floc forming tank 10 from the inflow pipe 11 flows down while forming a detour flow that repeats ascent and descent. That is, a long bypass path is formed in the floc forming tank 10. An overflow chamber 14 is formed on the side surface of the h-downstream chamber at the most downstream side of the floc forming tank 10. When the liquid level in the floc forming tank 10 reaches a certain level, the overflow chamber 14 flows into the overflow chamber 14. The water is drained out of the floc forming tank 10.

A nozzle 33 for injecting bubbles is disposed on the bottom surface of the chamber c in the floc forming tank 10. The nozzle 33 is connected to the bubble generator 20. The bubble generator 20 has a pressurizing pump 25, and is connected to the pump 25 via a flow control valve 22 and a reflux pipe 21 connected to the bottom surface of the h chamber located at the most downstream of the floc forming tank 10. In addition, an intake pipe 24 that sucks in the atmosphere via a flow control valve 22 is connected. Thus, the pressurizing pump 25 mixes the air into the water to be treated (treated water) introduced from the inside of the chamber and generates pressurized air-dissolved water (pressurized gas-dissolved liquid). Further, the discharge side of the pressurizing pump 25 is connected to a surplus air separation tank 27 via a water pipe 26.

The excess air separation tank 27 is a tank for removing excess air (excess gas) that has not been completely dissolved. As shown in FIG. 2, the excess air separation tank 27 includes a sealed casing 28 having a ceiling wall 28A having a hemispherical shape and a substantially cylindrical shape as a whole, and a vertically disposed inside of the casing 28, 26 and an ejection pipe 29 communicating with the ejection pipe 26. Excess air stored at the top of the casing 28 can be released to the atmosphere via a relief valve 30. Further, a supply pipe 3 is provided below the excess air separation tank 27.
One end is connected, and the other end is connected to the nozzle 33 via a pressure reducing valve 32.

Here, in the surplus air separation tank 27 according to the present embodiment, the opening 29A of the ejection pipe 29 through which the pressurized air dissolving water flows into the casing 28 is formed at the top of the ceiling wall 28A of the casing 28 (central portion). ), And the pressurized air-dissolved water rushes upward from the opening 29A. Then, the pressurized air-dissolved water spouted vigorously from the opening 29A collides with the ceiling wall 28A, is dispersed, and flows down into excess air accumulated at the top.

Next, the operation and effect of this embodiment configured as described above will be specifically described. As described above, before flowing into the floc forming tank 10, the water to be treated undergoes a process in which the flocculant is mixed and rapidly stirred. Then, the water to be treated flows into the chamber a in the floc forming tank 10 through the inflow pipe 11 at a predetermined pressure by a pump (not shown). Then, the aggregates in the water are transferred from the upper chamber a to the lowermost h.
It flows down while repeating ascending and descending while passing through each gap to the chamber. During this time, fine aggregates gather and gradually form flocs as larger lumps.

In the chamber c located at a relatively early stage of the floc forming process, air bubbles are ejected from the nozzle 33. In the bubble generator 20, the pressure pump 25
Then, air is mixed with the treated water taken in from the chamber h to generate pressurized air-dissolved water. Thereafter, the pressurized air dissolved water is sent to the surplus air separation tank 27.

The pressurized air-dissolved water sent to the surplus gas separation tank 27 separates the surplus air inside the casing 28 near the top. At this time, when the excess air stored in the casing 28 reaches a certain pressure or more, the relief valve 30
To keep the pressure inside the casing 28 constant. The pressurized air-dissolved water separated from the excess air in this way is supplied to the nozzle 33 via the supply pipe 31 in a state where the pressure is reduced to the atmospheric pressure by the pressure reducing valve 32. The air dissolved in the dissolving water is generated as fine bubbles, and the bubbles form the floc forming tank 10 from the nozzle 33 as bubbles.
Squirted into.

The bubbles ejected from the nozzle 33 adhere to the aggregates and float on the surface of the tank. By the way, in the chamber c to which the bubbles are supplied, the floc forming tank 1
Since the flow velocity in 0 is relatively high and the path length from the inflow pipe 11 is short, the aggregation of the aggregates has not progressed yet, and it is still in an immature stage as a floc. Thus, air bubbles adhere to the surface of the small immature aggregates. The floc formed by aggregating aggregates having such bubbles adhered to the surface as well as the inside of the floc has a large buoyancy, so that the floc floats in the middle of the floc forming tank 10. It is possible to reliably ascend to the surface without performing. Most of them rise and float on the water surface while forming a flock containing air bubbles during repeated ascent and descent from the chamber c to the chamber f. Thus, if the floating flocs are collected, they are drained from the outflow pipe 12 as desired treated water at the stage where they flow down into the chamber h.

In this embodiment, the surplus air separation tank 2
The pressurized air-dissolved water injected into 7 is injected into the casing 28 through the opening 29A of the ejection pipe 29. At this time, the pressurized air-dissolved water that vigorously jumps out of the opening 29A collides with the ceiling wall 28A and is dispersed to form the casing 2.
8 Drops into the surplus air layer near the top. At this time,
The surface of the pressurized air dissolving water that has already been accumulated inside the casing is disturbed by the pressurized air dissolving water poured down from the opening 29A near the surface layer of the dissolving water. It can be dissolved in air-dissolved water.

As described above, according to the surplus air separation tank of the present embodiment, the surplus air can be dissolved in the pressurized air dissolved water in the casing 28, and the solubility of air can be improved. Therefore, it is possible to increase the amount of bubbles ejected into the floc forming tank 10 and to effectively float aggregates. The pressurized air-dissolved water spouted from the opening 29A of the spouting pipe 29 forms a hemispherical ceiling wall 28.
Since it collides with A, it can be uniformly dispersed in the casing 28 and the excess air is easily dissolved.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition, various changes can be made without departing from the scope of the invention. (1) In the above-described embodiment, the ejection pipe 29 penetrates the inside of the casing 28. However, the pipe is routed outside the casing to provide an opening in the ceiling wall, and the pressurized air-dissolved water enters the inside from the opening. It may be a jet tube for injecting. (2) In the above embodiment, the ceiling wall 28 of the casing 28
Although A is a hemisphere, it may be one in which, for example, a corrugated plate is provided on the ceiling wall to disperse the pressurized air-dissolved water. (3) In the above embodiment, the opening 29 of the ejection pipe 29
A may be a nozzle. (4) In the floc forming tank 10 in the above embodiment, c
Although the nozzles 33 are provided in the layer, the nozzles may be provided in other layers. Alternatively, the nozzles may be provided in a plurality of layers, not limited to one c layer. May be. (5) In the above embodiment, the floc forming tank 10 is divided into a plurality of chambers, but may be constituted by one chamber.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main part of a water purification system according to an embodiment.

FIG. 2 is a schematic diagram of a surplus air separation tank.

FIG. 3 is a conceptual diagram illustrating steps of a conventional water treatment method.

[Explanation of symbols]

 27: Surplus air separation tank 28: Casing (main body) 28A: Ceiling wall 29: Spout tube (insertion tube) 29A: Opening (tip opening)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D011 AA01 AB10 AC01 4D037 AA11 AB02 BA03 BA23 CA06 CA08 4G035 AA01 AB22 AE13 AE19

Claims (2)

[Claims] 1. A pressurized gas-dissolved liquid produced by mixing a liquid and a gas in a pressurized state and dissolving the gas in the liquid is temporarily stored in a hermetically sealed body and mixed. A surplus gas separation tank for separating surplus gas not dissolved in the liquid from the gas above the liquid level of the pressurized gas dissolved liquid, wherein the pressurized gas is separated from an upper part where the surplus gas is stored. An excess gas separation tank, wherein the solution is dropped onto the surface of the pressurized gas solution stored in the main body. 2. A ceiling wall of the main body is formed in a dome shape, and an insertion pipe for injecting the pressurized gas solution into the main body is inserted into the main body, and a distal end opening of the insertion pipe is provided. 2. A surplus gas separation tank according to claim 1, wherein a portion is provided so as to face the ceiling wall, and the pressurized gas-dissolved water injected from the front end opening collides with the ceiling wall to be dispersed. .