【０００１】
【発明の属する技術分野】
本発明は排水中の浮遊物を分離する、加圧浮上処理装置に関するものである。
【０００２】
【従来の技術】
加圧浮上分離装置に関する従来の技術では加圧水の発生機構として、コンプレッサーにより加圧タンク内に空気を吹き込み、加圧タンク内部に設置した充填物により空気を水中に混合させて加圧水を得る方法。あるいは本発明と同様に加圧水ポンプの吐出側から吸い込み側に分岐配管を用いて、分岐配管に設置したエジェクターにより空気を吸い込みポンプ内でのキャビテーションにより空気を排水中に溶解させ、加圧タンク内に導いて滞留時間をとり、空気の溶解を促進しながら、これを加圧水として、排水中に配管で混合して圧力を開放して気泡を作り出す方式が主であった。この方法では機器としてのコンプレッサーの故障が多く、またコンプレッサーにより作られた気泡は大きく、短時間に十部な溶解が得られないだけでなく加圧水として利用される時点、すなわち排水との混合時にも大きな気泡が発生しやすい。またエジェクターで作り出す加圧水発生方法も従来型のエジェクターでは空気の完全な混合がエジェクター内部で起こらず、空気と水の２相流となって加圧ポンプ内に流入し、加圧水圧力の変動を起こし易く、またそのために極端なキャビテーションの発生により短時間に加圧水ポンプのインペラーを損傷しやすい欠点があった。このためエジェクターから吸引される空気量に最新の注意を払う調整が必要であった。
【０００３】
【発明が解決しようとする課題】
微細な気泡を選択的に効率よく発生し、これを排水と効率的に混合する機構を提供する。またこれまでの加圧浮上分離装置では排水中の浮遊物が加圧浮上槽の底部に沈殿しやすい欠点があったが、本発明はこの沈殿しやすい浮遊物を浮上槽の底部から再度浮上させる機構を提供する。
【０００４】
【課題を解決するための手段】
本発明では加圧水の発生機構として加圧浮上槽処理水を加圧ポンプに吸引し、吐出側配管を加圧タンクに送水する途中に分岐管を設置してこの分岐管の途中にエジェクターを設置して加圧水ポンプの吸引側に連結して、エジェクターにより空気を吸引するがこの際エジェクター内部の攪拌翼により水流を激しく回転させ空気の吸い込みと混合をエジェクター内部で行ない、ほほ均一と成った気液混合流を加圧ポンプ内で更に激しく混合させるため、加圧ポンプ内のキャビテーションによる振動が比較的小さく、空気の溶け込みも十分に行なわれる。
また加圧タンク内に送液された空気の溶け込んだ加圧水は加圧タンク内部での下向きの旋回流により、微細な気泡のみが下降流で運ばれながら水中に溶解する。大きな気泡は旋回中に中心部に自然に集まり、加圧タンク頭頂部に設置したオーバーブロー管から加圧タンク外部に流出する。本発明ではこの下向きの旋回流により空気の溶解した加圧水と微細な気泡のみが加圧水として排水と混合される。この機構により、排水と混合される時点で、圧力が開放された加圧水は煙るような微細な気泡を発生させ、従来のような大きな気泡は混合しない。そのため排水中の浮遊物との接触が迅速に起こり、かつ排水中のたんぱく質や油脂分等の界面に集まる疎水性物質も多量に発生した微細気泡上に迅速に収着する。またこの汚れを収着させた微細気泡のため気泡の持続時間が長く、数日の加圧水の停止でも浮遊物は沈殿しにくい。
また本発明では加圧水と排水の混合時に簡単な工夫により、加圧水を旋回させながら排水と混合して斜め上方に流出させるがこの際、加圧浮上槽内でこの吐出口を上下方向を除き囲い込む構造としている。この構造により、加圧浮上槽内の流入口ではこの囲い込み構造物の下の開放部周辺に竜巻のような旋回する流れが発生する。この旋回流は底部の沈殿物を引き剥がす力があり、沈殿し易い浮遊物も何度も加圧浮上槽内部を循環する浮上槽内部の機構上の流れと、この旋回流により、浮上槽内部に沈殿物は蓄積せず、長期に亘って底洗浄なしに使用できる。
【０００５】
【発明の実施の形態】
図面によって本発明の具体例を説明する。図１は本発明の加圧浮上装置の説明図である。
【０００６】
【発明の効果】
本発明では従来の加圧浮上設備に比べて次のような利点がある。
（１）加圧水中の空気の溶解混合が十分で，かつ従来のものとは異なり、加圧水タンク内部で旋回する下降流と加圧タンク頭頂の中心部から抜ける配管構造により微細な気泡を選択的に溶解するため均質な加圧水を発生させられる。
（２）この微細気泡の発生と次に（３）で述べる旋回する混合機構荷より，浮遊物との混合が十分で、かつ溶解成分の収着も十分に起こるため汚濁成分の分離効率がよい。
（３）加圧浮上装置の内部に沈殿しやすい浮遊物を含む排水でも、加圧水の加圧浮上槽への流入混合時に旋回する機構と加圧水槽内部の上下方向に開口部を持った囲い込み構造により発生する旋回上昇流と加圧浮上槽内部の循環流により絶えず沈殿物を引き寄せ浮上させる機構があるために、処理水が汚濁しにくく、長期間、清掃等維持管理作業としては手間のかかる浮上槽底部洗浄無しに使える。
【０００７】
【実施例１】
浮遊物濃度１２７０ｐｐｍ、ＢＯＤ濃度２７００ｐｐｍの食品工場排水を原水として本装置で処理した場合と、コンプレッサーと４段の他段ポンプを使用で直接加圧タンクを加圧して加圧水を作った場合を比較した。後者は本装置のエジェクター分岐配管、加圧水タンク内の旋回下降流、加圧水と排水の混合時に加圧水を旋回させる機構、および加圧水と混合された排水の流入部に本装置のように囲い構造を持たずに加圧浮上槽内に流入させた場合である。
加圧浮上分離後の処理水を比較した。（時間処理量１０ｍ３／ｈとした）
装置の大きさは加圧水ポンプ７．５ｋｗ、加圧浮上槽外形 ２ｍ×６ｍ×２ｍｈで共通
原水：浮遊物濃度 １２７０ｐｐｍ、ＢＯＤ濃度２７００ｐｐｍ
【実施例２】
実施例１の排水を用いて、無機凝集剤として硫酸バンド５００ｐｐｍ、高分子凝集剤１００ｐｐｍを添加して攪拌する凝集反応槽を経由した場合
原水：浮遊物濃度 １２７０ｐｐｍ、ＢＯＤ濃度２７００ｐｐｍ
【実施例３】
実施例１の加圧浮上槽においてあらかじめ沈殿槽から採取した活性汚泥を加圧浮上槽内部の底部に沈殿物として５ｃｍ深さに堆積させてから、排水で加圧浮上槽を満たし、加圧ポンプを起動させ、通常の処理を２４時間行い、浮上槽を観察し、その後排水して、底部沈殿物の有無を調べた。
【図面の簡単な説明】
【図１】本発明の構造を持つ加圧浮上装置の構造説明図である。
【図２】本発明の構造を持つ加圧水発生機構のうち加圧水ポンプ周辺模式図である。
【図３】本発明の構造を持つ加圧水タンクの構造説明図である。
【図４】本発明の構造を持つ加圧浮上装置の加圧水および凝集反応槽出の排水の流入口部の構造説明図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure flotation apparatus for separating suspended matter in wastewater.
[0002]
[Prior art]
In the prior art relating to the pressurized flotation device, a method of generating pressurized water by blowing air into a pressurized tank by a compressor and mixing the air into water by a filler installed in the pressurized tank is used as a pressurized water generating mechanism. Alternatively, using a branch pipe from the discharge side to the suction side of the pressurized water pump in the same manner as the present invention, air is sucked by an ejector installed in the branch pipe and air is dissolved in drainage by cavitation in the pump, and is discharged into the pressurized tank. The main method has been to form air bubbles by using the pressurized water as a pressurized water and mixing it with drainage pipes to release the pressure while promoting the dissolution of air while taking a residence time. In this method, the compressor as a device often suffers from failure, and the bubbles generated by the compressor are large, so that not only insufficient dissolution can be obtained in a short time, but also when it is used as pressurized water, that is, at the time of mixing with wastewater. Large bubbles are easily generated. Also, the method of generating pressurized water created by the ejector is such that in the conventional ejector, complete mixing of air does not occur inside the ejector, but flows into the pressurized pump as a two-phase flow of air and water, and the pressure of the pressurized water tends to fluctuate. Further, there is a disadvantage that the impeller of the pressurized water pump is easily damaged in a short time due to the occurrence of extreme cavitation. Therefore, it was necessary to adjust the amount of air sucked from the ejector with the latest attention.
[0003]
[Problems to be solved by the invention]
Provided is a mechanism for selectively and efficiently generating fine bubbles and efficiently mixing them with wastewater. In addition, the conventional pressure flotation apparatus had a drawback that the suspended matter in the drainage easily settled to the bottom of the pressure flotation tank, but the present invention causes the sedimented suspended matter to float again from the bottom of the flotation tank. Provide a mechanism.
[0004]
[Means for Solving the Problems]
In the present invention, as a pressurized water generation mechanism, a pressurized floating tank treated water is sucked into a pressurized pump, and a branch pipe is installed in the middle of feeding the discharge side pipe to the pressurized tank, and an ejector is installed in the middle of the branch pipe. Connected to the suction side of the pressurized water pump and sucks air by the ejector. At this time, the water flow is violently rotated by the stirring blades inside the ejector, and the suction and mixing of air are performed inside the ejector, resulting in almost uniform gas-liquid mixing. Since the flow is mixed more vigorously in the pressure pump, the vibration due to the cavitation in the pressure pump is relatively small, and the air is sufficiently dissolved.
Further, the pressurized water into which the air sent into the pressurized tank is dissolved dissolves in the water by the downward swirling flow inside the pressurized tank while only the fine bubbles are carried by the downward flow. Large bubbles naturally gather at the center during the turning, and flow out of the pressurized tank from an overblow pipe installed at the top of the pressurized tank. In the present invention, only the pressurized water in which air is dissolved and fine bubbles are mixed with the wastewater as pressurized water by the downward swirling flow. By this mechanism, when mixed with the waste water, the pressurized water which has been released from the pressure generates fine bubbles like smoke, and large bubbles as in the prior art do not mix. As a result, contact with suspended matter in the wastewater occurs promptly, and hydrophobic substances that collect at the interface of proteins and oils and fats in the wastewater quickly sorb on the fine bubbles generated in large quantities. In addition, the duration of the bubbles is long due to the fine bubbles in which the dirt is sorbed, and the suspended matter is hardly settled even if the pressurized water is stopped for several days.
In the present invention, the pressurized water is mixed with the drainage while being swirled and discharged obliquely upward while the pressurized water is swirled by a simple device when mixing the pressurized water and the drainage water. It has a structure. With this structure, a swirling flow like a tornado is generated around the open portion below the enclosed structure at the inflow port in the pressurized flotation tank. This swirling flow has the power to peel off the sediment at the bottom, and the suspended matter that easily sediments flows on the mechanism inside the floating tank that circulates inside the pressurized floating tank many times. No sediment builds up and can be used for a long time without bottom washing.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
A specific example of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view of a pressure flotation device of the present invention.
[0006]
【The invention's effect】
The present invention has the following advantages over the conventional pressurized flotation equipment.
(1) Dissolving and mixing of air in pressurized water is sufficient, and unlike conventional ones, fine bubbles can be selectively removed by the descending flow swirling inside the pressurized water tank and the piping structure exiting from the center of the top of the pressurized tank. Uniform pressurized water can be generated to dissolve.
(2) Due to the generation of the microbubbles and the swirling mixing mechanism load described in (3), the mixing with the suspended matter is sufficient and the sorption of the dissolved component occurs sufficiently, so that the separation efficiency of the pollutant component is good. .
(3) A mechanism for rotating pressurized water into and out of the pressurized flotation tank even for wastewater containing suspended matter that easily precipitates inside the pressurized flotation device, and a surrounding structure with vertical openings inside the pressurized water tank Because of the mechanism that constantly draws and floats sediment by the generated swirling upward flow and the circulating flow inside the pressurized floating tank, the treated water is less likely to become polluted, and it takes a long time for maintenance work such as cleaning. Can be used without bottom wash.
[0007]
Embodiment 1
A comparison was made between the case where wastewater from a food factory having a suspended matter concentration of 1270 ppm and a BOD concentration of 2700 ppm was treated as raw water by the present apparatus and the case where pressurized water was produced by directly pressurizing a pressurized tank using a compressor and a four-stage other-stage pump. . The latter does not have an enclosure structure like the present device in the ejector branch pipe of this device, the swirling downward flow in the pressurized water tank, the mechanism for turning the pressurized water when mixing the pressurized water and the drainage, and the inflow part of the wastewater mixed with the pressurized water. This is the case where the gas is caused to flow into the pressurized floating tank.
The treated water after pressure flotation was compared. (Time throughput was 10 m 3 / h)
The size of the device is 7.5 kw of pressurized water pump, external size of pressurized flotation tank 2 mx 6 mx 2 mh, common raw water: suspended matter concentration 1270 ppm, BOD concentration 2700 ppm
Embodiment 2
Using the waste water of Example 1 and passing through a flocculation reaction tank in which 500 ppm of a sulfuric acid band and 100 ppm of a high-molecular flocculant are added and stirred as an inorganic flocculant Raw water: suspended matter concentration 1270 ppm, BOD concentration 2700 ppm
Embodiment 3
Activated sludge previously collected from the sedimentation tank in the pressure flotation tank of Example 1 is deposited as a sediment at a depth of 5 cm on the bottom inside the pressure flotation tank, and then the pressure flotation tank is filled with drainage water and the pressure pump is pumped. Was started, normal processing was performed for 24 hours, the floating tank was observed, then drained, and the presence or absence of bottom sediment was examined.
[Brief description of the drawings]
FIG. 1 is a structural explanatory view of a pressure flotation device having the structure of the present invention.
FIG. 2 is a schematic view showing a periphery of a pressurized water pump in a pressurized water generating mechanism having a structure of the present invention.
FIG. 3 is a structural explanatory view of a pressurized water tank having the structure of the present invention.
FIG. 4 is a structural explanatory view of an inflow portion of pressurized water and drainage from a coagulation reaction tank of the pressurized flotation device having the structure of the present invention.