JP2997874B2 - Vertical pump - Google Patents
Vertical pumpInfo
- Publication number
- JP2997874B2 JP2997874B2 JP23617096A JP23617096A JP2997874B2 JP 2997874 B2 JP2997874 B2 JP 2997874B2 JP 23617096 A JP23617096 A JP 23617096A JP 23617096 A JP23617096 A JP 23617096A JP 2997874 B2 JP2997874 B2 JP 2997874B2
- Authority
- JP
- Japan
- Prior art keywords
- pump
- intake
- water level
- intake hole
- suction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
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- Structures Of Non-Positive Displacement Pumps (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、吸水槽内に設置さ
れる立軸ポンプに関し、特に、吸水槽内の水位低下時に
おいても揚水運転を可能とし、例えば降雨時の出水を排
水するために設けられる先行待機運転を実施する立軸ポ
ンプとして好適であり、平常時におけるポンプの管理運
転にも利用できるものに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical pump installed in a water absorption tank, and more particularly to a vertical pump installed in a water absorption tank to enable pumping operation even when the water level in the water absorption tank is low, for example, to drain water discharged during rainfall. The present invention relates to a pump which is suitable as a vertical pump for performing a preceding standby operation and can be used for a pump management operation in normal times.
【０００２】[0002]
【従来の技術】従来のこの種立軸ポンプは、特開昭６３
−９０６９７号公報に記載されているように、ポンプ没
水時の水位がこれ以下では空気を吸込んでしまう最低水
位レベルに相当するポンプ固有のポンプ特定部位より僅
かに上方位置に羽根車を設け、上記最低水位レベル相当
する水位より低い水位になったとき、真空破壊により空
転状態とし、落水させて排水運転ができないようにした
ものがある。2. Description of the Related Art A conventional vertical shaft pump of this type is disclosed in
As described in -90697, an impeller is provided at a position slightly higher than a pump-specific pump specific portion corresponding to a minimum water level at which the water is sucked when the water level at the time of submersion of the pump is below this level. When the water level becomes lower than the water level corresponding to the minimum water level, there is a type in which a vacuum break is performed to make the wheel idle, and the water is dropped to prevent the drainage operation.
【０００３】また、従来の他の立軸ポンプとしては、実
開昭６３−１５００９７号公報に記載されているよう
に、吸水槽水位より低いところに羽根車を位置させ、羽
根車の入口付近に外部に通じる貫通穴を設け、該貫通穴
は管と接続され、該管の他端は、吸水槽内の、前記羽根
車が水没するレベル付近に開口部を設けるものが知られ
ている。As another conventional vertical shaft pump, as described in Japanese Utility Model Application Laid-Open No. 63-150997, an impeller is located at a position lower than the water level of a water absorption tank, and an external pump is provided near an inlet of the impeller. It is known that a through hole is provided to communicate with a pipe, and the through hole is connected to a pipe, and the other end of the pipe is provided with an opening in a water absorption tank near a level where the impeller is submerged.
【０００４】[0004]
【発明が解決しようとする課題】通常、降雨情報などに
基づいて先行待機運転を行うには、吸水槽や管渠の貯留
効果が増大することから、出来る限り低い水位で、排水
運転ができることが望ましく、かつ、吸水槽の水位レベ
ルに応じ適切な流量とすることが、渦防止や吸水槽のサ
ージ減少に有効で、ポンプの安定な運転ができる。Normally, in performing the preliminary standby operation based on rainfall information or the like, the drainage operation can be performed at the lowest possible water level because the storage effect of the water absorption tank and the sewer increases. It is desirable to set the flow rate to be appropriate and appropriate in accordance with the water level of the water absorption tank, which is effective for preventing vortices and reducing surges in the water absorption tank, and enables stable operation of the pump.
【０００５】しかしながら上記従来技術のうち前者のも
のは最低水位レベルより低い水位で排水運転する配慮が
されておらず例えば、吸込ベルの吸込口からこれの径の
１．４〜１．７倍の公知の最低水位レベルより低い水位
では排水運転ができない。However, the former one of the above-mentioned prior arts does not take into consideration draining operation at a water level lower than the minimum water level. For example, the diameter of the suction bell is 1.4 to 1.7 times the diameter of the suction bell through the suction port. Drainage operation cannot be performed at a water level lower than the known minimum water level.
【０００６】上記従来技術のうち後者のものによれば、
吸水槽の水位が、前記開口部のレベルより低下すれば開
口部より空気を吸込み、水位の低下と共にポンプの揚水
作用が徐々に低下するため、低い水位において揚水運転
が可能となり、かつ空転状態への推移が急激に起こらな
いという特徴があり、例えば吸水槽への急激な流入が生
ずる前に、ポンプを空転・待機するいわゆる先行待機運
転を行なうポンプに適したものであると思われる。この
立軸ポンプは、前記貫通穴と通じる管の他端を吸水槽内
の羽根車が水没するレベル付近に開口させ、水位がこの
開口部以下に低下したときに空気を吸込むようにしてい
るので、ポンプが吸気を開始する水位を、前記開口部の
設置レベルにより決定できるという特徴があるが、水位
が開口部の設定レベルより高いときは、開口部より吸水
するため、揚水中にゴミ等の異物を含んでいる場合、こ
の異物が運転時間の経過と共に開口部を閉鎖し、吸気作
用を阻害することが懸念される。特に前述の先行待機運
転を行なう排水ポンプでは、都市の広域に降った雨水が
急激に吸水槽へ流入するため、種々の異物が流入する可
能性がある。According to the latter of the above prior arts,
If the water level of the water absorption tank falls below the level of the opening, air is sucked in from the opening, and the pumping action of the pump gradually decreases with the drop of the water level. This characteristic is suitable for a pump that performs a so-called advance standby operation in which the pump idles and waits before an abrupt inflow into the water absorption tank occurs, for example. In this vertical shaft pump, the other end of the pipe communicating with the through hole is opened near the level at which the impeller in the water absorption tank is submerged, and air is sucked when the water level falls below this opening. There is a feature that the water level at which intake is started can be determined by the installation level of the opening.However, when the water level is higher than the set level of the opening, water is absorbed from the opening. In such a case, there is a concern that the foreign matter closes the opening with the elapse of the operation time and inhibits the intake operation. In particular, in the above-described drain pump that performs the preliminary standby operation, since rainwater that has fallen over a wide area of the city rapidly flows into the water absorption tank, various foreign substances may flow in.
【０００７】更に、後者のものは、吸水槽内の水位に応
じて、即ち水位が低くなるほど吸気量を増加させ排水量
か低下するようにしているが、吸気をしながら排水運転
をするには、安定した吸気がおこなわられなけらばなら
ない。しかし、この従来技術には安定した吸気を行うこ
とに関しての配慮が為されていない。Further, in the latter, the amount of intake air is increased and the amount of drainage is decreased in accordance with the water level in the water absorption tank, that is, as the water level becomes lower. Stable intake must be performed. However, this prior art does not take into consideration stable air intake.
【０００８】本発明の目的は、水位に応じてポンプの流
量を制御し、有害な渦を発生せずに最低水位レベルより
低い水位で安定に排水運転を可能とする立軸ポンプを得
ることにある。SUMMARY OF THE INVENTION It is an object of the present invention to provide a vertical pump that controls the flow rate of a pump in accordance with the water level and enables stable drainage operation at a water level lower than a minimum water level without generating harmful vortices. .
【０００９】[0009]
【００１０】[0010]
【００１１】[0011]
【課題を解決するための手段】上記目的を達成するた
め、本発明は、ポンプ運転中の水位が、それ以下では、
吸込ベルより空気を吸い込んでしまう最低水位レベルに
相当する位置より下方にポンプの羽根車を位置させ、こ
の羽根車の下方のポンプケーシングに吸気孔を設け、こ
の吸気孔に吸気管の一端を接続すると共に、その他端
を、ポンプ吸水槽の最高水位より高いレベルにて大気に
開放させ、かつ前記吸気孔開口付近の前記ポンプケーシ
ング内壁面に突出部を設けたことを特徴とする。In order to achieve the above-mentioned object, the present invention provides a method for producing a pump, comprising the steps of:
The pump impeller is located below the position corresponding to the lowest water level at which air is sucked from the suction bell, and an intake hole is provided in the pump casing below the impeller, and one end of the intake pipe is connected to this intake hole. And the other end is opened to the atmosphere at a level higher than the maximum water level of the pump suction tank, and the pump case near the intake hole opening is opened.
The protrusion is provided on the inner wall surface of the ring .
【００１２】前記吸気管の一端はポンプケーシングを貫
通してポンプケーシング内に突出させ、該吸気管の開口
端を吸気孔とすることも有効である。It is also effective that one end of the intake pipe penetrates through the pump casing and protrudes into the pump casing, and the open end of the intake pipe is used as an intake hole.
【００１３】[0013]
【００１４】[0014]
【００１５】次に本発明の作用を説明する。◆ポンプ羽
根車に近接して設けられた吸気孔位置付近では、吸込ま
れる水が旋回して流れているため、その水の遠心力が吸
気孔に作用して、吸気孔位置で十分な負圧が得られず、
したがって十分な吸気量が得られない。Next, the operation of the present invention will be described. ◆ In the vicinity of the position of the intake hole provided near the pump impeller, since the sucked water is swirling and flowing, the centrifugal force of the water acts on the intake hole, and sufficient negative pressure occurs at the position of the intake hole. Pressure is not available,
Therefore, a sufficient intake amount cannot be obtained.
【００１６】ポンプケーシング吸気孔を設け、吸気をし
ながら排水運転をする場合、吸気孔はポンプ羽根車に近
接して設けられているため、羽根車からの旋回している
逆流の影響を受け、吸気孔位置の圧力が不安定となるた
め、吸気量が安定せず振動が発生することがわかった。In the case of providing a pump casing suction hole and performing a draining operation while sucking air, since the suction hole is provided near the pump impeller, the suction hole is affected by the swirling backflow from the impeller. Since the pressure at the position of the intake hole became unstable, it was found that the amount of intake air was not stable and vibration occurred.
【００１７】また、ポンプ羽根車に近接して設けられた
吸気孔位置付近では、吸込まれる水が旋回して流れてい
るため、その水の遠心力が吸気孔に作用して、吸気孔位
置で十分な負圧が得られず、したがって十分な吸気量が
得られない。In addition, in the vicinity of the position of the intake hole provided in the vicinity of the pump impeller, since the water to be sucked is swirling and flowing, the centrifugal force of the water acts on the intake hole, and the position of the intake hole is reduced. , A sufficient negative pressure cannot be obtained, and therefore a sufficient intake air amount cannot be obtained.
【００１８】本発明では、突出部を吸気孔に近接して設
けることにより、吸気付近の旋回流れを防止、あるいは
低減できるから、吸気孔をケーシング内壁面上に設けな
くてもよく、旋回の流れの影響を最小限にでき、安定し
た吸気が行える。In the present invention, since the swirling flow near the intake air can be prevented or reduced by providing the protruding portion close to the intake hole, the intake hole does not have to be provided on the inner wall surface of the casing. Influence can be minimized, and stable intake can be performed.
【００１９】また、本発明においては、前述のように吸
気管の大気への開口部を、吸水槽の最高水位より高い位
置に設けているので、開口部に、吸水槽内の水に浮遊す
るゴミ等の異物が吸着し、水位低下時の吸気作用が阻害
されるということが起こらない。Further, in the present invention, since the opening of the intake pipe to the atmosphere is provided at a position higher than the maximum water level of the water absorption tank as described above, the air is suspended in the water in the water absorption tank at the opening. It does not occur that foreign substances such as dust are adsorbed and the intake action at the time of lowering the water level is hindered.
【００２０】さらに、羽根車入口のポンプケーシングに
設けた吸気孔について、ポンプ軸心に垂直な平面に対し
傾斜して設けるか、あるいは最小内径部より下方にずれ
た位置に設ける。あるいは前記吸気孔の上部又は下部の
ポンプケーシング内壁面に、突出部を設ける等の手段に
より、ポンプケーシング内の流れを利用し前記開孔口に
おける圧力を増減できるので、与えられたポンプの仕様
及び寸法に対し、吸気を開始したい吸水槽の水位におい
て、上記開口部の圧力を大気圧と一致するようにでき、
これより以下の水位で給気作用を行わせることができ
る。Further, the intake hole provided in the pump casing at the impeller inlet is provided to be inclined with respect to a plane perpendicular to the pump axis, or to be provided at a position shifted downward from the minimum inner diameter portion. Alternatively, the pressure at the opening can be increased or decreased by using a flow in the pump casing by means such as providing a protruding portion on the inner wall surface of the pump casing at the upper or lower part of the intake hole. For the dimensions, at the water level of the water absorption tank where it is desired to start intake, the pressure of the opening can be made to match the atmospheric pressure,
Thus, the air supply operation can be performed at the following water level.
【００２１】[0021]
【発明の実施の形態】以下、本発明の実施例を図により
説明する。◆図１において、羽根車１を収納したポンプ
ケーシング４のケーシングライナー２の下方向にポンプ
ケーシングの吸込ベル３が接続され、かつ、上方側には
ポンプケーシング４の一部である揚水管５および吐出エ
ルボ６が接続され立軸ポンプを構成している。吐出エル
ボ６の吐出側には吐出管７及び吐出弁８が設けられてい
る。また、羽根車１の下方近傍には吸気孔９が設けら
れ、この吸気孔９と連結して吸気管１０が設けられ、さ
らに吸気管１０に吸気量調整弁１１が設けられ、吸気管
１０の吸込口１２が吸水槽２０内の、最高水位（ＨＷ
Ｌ）より高い位置に設置されている。これらにより流量
制御装置が構成されている。吸気孔９は従来の最低水位
レベル、すなわち、この水位以下では吸込ベル３の下端
から空気を吸込んでしまうポンプ固有の最低水位レベル
ＷＬ１において該吸気孔９から吸気されない位置に設け
られている。吸気孔９における静圧Ｐ（ｍ）は、次式で
表わされる。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the suction bell 3 of the pump casing is connected to the lower side of the casing liner 2 of the pump casing 4 in which the impeller 1 is housed, and the pumping pipe 5 which is a part of the pump casing 4 and the upper side. The discharge elbow 6 is connected to form a vertical pump. On the discharge side of the discharge elbow 6, a discharge pipe 7 and a discharge valve 8 are provided. In addition, an intake hole 9 is provided near the lower portion of the impeller 1, an intake pipe 10 is provided in connection with the intake hole 9, and an intake air amount adjusting valve 11 is provided in the intake pipe 10. The suction port 12 is the highest water level (HW
L) It is installed at a higher position. These constitute a flow control device. The intake hole 9 is provided at a position where the air is not sucked from the intake hole 9 at the conventional minimum water level, that is, at the minimum water level WL1 specific to the pump in which air is sucked from the lower end of the suction bell 3 below this water level. The static pressure P (m) at the intake hole 9 is represented by the following equation.
【００２２】 Ｐ＝Ｐｏ＋ｌ−ｈs−ｋ・υ2／２ｇ …… ここで、Ｐｏ：大気（１０.３３ｍ）、ｌ：（水位レベ
ル）（ｍ）、ｈs：ポンプケーシング吸込部損失水頭
（ｍ）、υ：吸気孔部の取扱液の流速（ｍ）、ｋ：定
数、である。P = Po + l−h s −k · υ 2 / 2g where Po: atmosphere (10.33 m), l: (water level) (m), h s : head loss of pump casing suction part ( m), υ: flow rate (m) of the liquid handled in the suction hole, k: constant.
【００２３】吸気孔における静圧ＰがＰｏより大きくな
れば吸気はしない。よって、ｌ＞ｈs＋ｋ・υ2／２ｇと
すれば吸気はしない。従って従来の最低水位レベルＷＬ
１より下方でＬ1＝ｈs＋ｋ・υ2／２ｇだけ下方の位置
に吸気孔９を設ける。従って水位が、ＷＬ１以上の範囲
Ａでは吸気をしないので、所定のポンプ能力で排水運転
を行うことができる。水位が、ＷＬ１より低い範囲Ｂで
は式においてｌが減少するので、Ｐが大気圧より小さ
くなり吸気を行う。吸気量は吸気量調節弁１１により、
適切な損失が与えられているので、水位に伴い、適切な
量の吸気を行い流量制御を行う。範囲Ｂにおいて、水位
が、ＷＬ２の場合は、Ｐは大気圧により若干低い程度で
あるので吸気量が少なく、ポンプの流量も若干減少す
る。この場合、ポンプの没水深さＳ１はこの時のポンプ
流量に対して十分であるので渦は発生しない。水位がＷ
Ｌ３の場合、Ｐは水位の低下にほぼ比例して低下するの
で、大気圧よりその分小さくなり、吸気量が増大し、ポ
ンプの流量も大幅に少なくなり、没水深さＳ２でも渦が
発生しない流量とすることができる。水位がＷＬ４の場
合、吸気量はポンプ流量の１.５％〜２０％となり揚水
不能となって空転運転状態となる。この時の没水深さＳ
３は、揚水不能となる直前の流量において渦の発生しな
い長さになるように、吸込ベル入口のレベルを設計す
る。なお、水位の変動する全範囲において、吸気量調節
弁１１の開度は一定にしてよく、あるいは、水位によっ
て開度を変更してもよい。従来の最低水位レベルＷＬ１
以下でも渦が発生せず、異常な振動や騒音のでない安全
な運転が可能となる。空転運転から揚水運転に移行する
羽根車１が若干没水する水位及び排水運転から空転運転
に移行する水位ＷＬ４より若干高い水位において、ポン
プの流量は吸気により所定の流量の約半分程度の制御さ
れているので、排水開始及び排水停止時の流量変化が少
なく、サージ現象が緩和できポンプの安定な運転が可能
である。◆なお、２１は吸込水槽（吸水槽）２０の低壁
である。If the static pressure P in the intake hole becomes larger than Po, no intake is performed. Therefore, if l> h s + k · υ 2 / 2g, no intake is performed. Therefore, the conventional minimum water level WL
1 L 1 = h s + k · υ 2 / 2g simply by providing inlet openings 9 in a position lower than at the lower. Therefore, since the intake is not performed when the water level is in the range A of WL1 or more, the drainage operation can be performed with a predetermined pump capacity. In the range B where the water level is lower than WL1, 1 decreases in the equation, so that P becomes smaller than the atmospheric pressure and the air is taken. The intake air amount is controlled by the intake air amount adjusting valve 11.
Since an appropriate loss is given, an appropriate amount of intake is performed according to the water level to control the flow rate. In the range B, when the water level is WL2, P is slightly lower due to the atmospheric pressure, so the intake air amount is small, and the flow rate of the pump is also slightly reduced. In this case, since the submersion depth S1 of the pump is sufficient for the pump flow at this time, no vortex is generated. Water level is W
In the case of L3, P decreases almost in proportion to the decrease in the water level, so that it becomes smaller than the atmospheric pressure, the intake air amount increases, the flow rate of the pump decreases significantly, and no vortex occurs even at the submerged depth S2. It can be a flow rate. When the water level is WL4, the intake air amount becomes 1.5% to 20% of the pump flow rate, making it impossible to pump up water and entering an idling operation state. Submersion depth S at this time
3 designs the level of the suction bell inlet so that vortex does not occur at the flow rate immediately before pumping is impossible. Note that the opening of the intake air amount control valve 11 may be constant over the entire range in which the water level fluctuates, or the opening may be changed depending on the water level. Conventional minimum water level WL1
Even in the case below, no vortex is generated, and safe operation without abnormal vibration or noise can be performed. At a water level at which the impeller 1 that shifts from the idling operation to the pumping operation is slightly submerged and at a water level slightly higher than the water level WL4 that shifts from the drainage operation to the idling operation, the flow rate of the pump is controlled to about half of a predetermined flow rate by the suction. Therefore, there is little change in the flow rate at the start of drainage and at the time of drainage stop, the surge phenomenon can be reduced, and the pump can operate stably. Reference numeral 21 denotes a low wall of the suction water tank (water absorption tank) 20.
【００２４】さて、ここで、従来の最低水位レベルＷＬ
１と吸気孔９設置位置とのレベル差Ｌ１は、式の関係
から、Ｌ1＝ｈs＋ｋ・υ2／２ｇとすることが望ましい
が、Ｌ1はうずの発生しやすさから決り、一般にポンプ
の口径の関数となり、上記式の右辺はυの関数である
が、υはポンプの吐出し量、仕様全揚程、比速度等によ
り異なるため、もしｋ＝１で固定されている場合、ポン
プによって常にＰ点の圧力を大気圧に等しく計画できる
とは限らない。即ち、大口径で揚程の低いポンプではＬ
1＞ｈs＋ｋ・υ2／２ｇとなり、逆に比較的小口径で揚
程の高いポンプはＬ1が小さく、υは大となるためＬ1＜
ｈs＋ｋ・υ2／２ｇとなる。したがって、ｈs＋ｋ・υ2
／２ｇにおいて、ｋが１以外の値をとれるようにするこ
とが望ましい。ｋがｌ以外の値をとれるようにした具体
的実施例を図２〜図８により説明する。Now, here, the conventional minimum water level WL
1 and the level difference L1 between the intake holes 9 installation position, from the equation of the relationship, it is desirable that the L 1 = h s + k · υ 2 / 2g, L 1 is determined from the generation ease of vortex, generally It is a function of the diameter of the pump, and the right side of the above equation is a function of υ. Since υ varies depending on the pump discharge amount, the specified total head, the specific speed, etc., if k = 1 is fixed, the pump Therefore, the pressure at the point P cannot always be planned to be equal to the atmospheric pressure. That is, for a large diameter pump with a low head, L
1 > h s + k · υ 2 / 2g. Conversely, a pump having a relatively small diameter and a high head has a small L 1 and a large υ, so that L 1 <
h s + k · υ 2 / 2g. Therefore, h s + k · υ 2
It is desirable that k can take a value other than 1 in / 2g. A specific embodiment in which k can take a value other than 1 will be described with reference to FIGS.
【００２５】図２は本発明の第１実施例を示すもので、
図１における吸気孔９の近傍を示す詳細図である。羽根
車の入口近傍のポンプケーシング２には、複数の吸気孔
９がポンプケーシング２の周方向に等間隔に設けられて
いる。また、この吸気孔９は、ポンプ軸心に垂直な平面
に対しポンプケーシング内の流れの方向に傾斜して設け
られている。したがって吸気孔９における静圧Ｐ（ｍ）
は、前述の式で表わしたとき、ｋの値はｋ＞１とな
る。一方、図３に示す本発明の第２実施例においては吸
気孔９が、ポンプケーシング内の流れと逆の方向に傾斜
して設けられてあるので０＜ｋ＜１となる。このように
吸気孔９を、ポンプ軸心に垂直な平面に対し、傾斜して
設けることにより式のｋの値を１より増減できる。FIG. 2 shows a first embodiment of the present invention.
FIG. 2 is a detailed view showing the vicinity of an intake hole 9 in FIG. 1. In the pump casing 2 near the impeller inlet, a plurality of intake holes 9 are provided at equal intervals in the circumferential direction of the pump casing 2. The intake hole 9 is provided to be inclined in the direction of flow in the pump casing with respect to a plane perpendicular to the pump axis. Therefore, the static pressure P (m) in the intake hole 9
Is represented by the above equation, the value of k is k> 1. On the other hand, in the second embodiment of the present invention shown in FIG. 3, since the intake hole 9 is provided to be inclined in the direction opposite to the flow in the pump casing, 0 <k <1. By providing the intake hole 9 at an angle to the plane perpendicular to the pump axis, the value of k in the equation can be increased or decreased from 1.
【００２６】図４は、図２の実施例で吸気孔を傾斜させ
る代りに、吸気孔端部を、ポンプケーシング内に突出さ
せた曲管により構成したものである。すなわち、吸気管
１０がポンプケーシングを貫通するようにし、吸気管１
０の先端を折り曲げてポンプケーシング内の流れ方向に
対しα°の角度傾いた方向に開口部がむくようにして吸
気孔９を形成したものである。この角度αにより、式
のｋの値は図５に示すように変化する。したがって、上
記角度αを適宜選定することにより、ｋの値を容易に増
減できる。FIG. 4 shows the embodiment of FIG. 2 in which, instead of inclining the intake hole, the end of the intake hole is formed by a curved pipe projecting into the pump casing. That is, the intake pipe 10 penetrates the pump casing, and the intake pipe 1
The intake hole 9 is formed by bending the front end of the opening 0 so as to open the opening in a direction inclined by α ° with respect to the flow direction in the pump casing. Depending on the angle α, the value of k in the equation changes as shown in FIG. Therefore, the value of k can be easily increased or decreased by appropriately selecting the angle α.
【００２７】図６は本発明の第４実施例を示すもので、
吸気孔９は、ポンプケーシングの吸込ベル３の最小内径
Ｄminの位置より下方に設けている。この吸気孔９取付
部の直径はＤminより大きいのでＤmin部より静圧が高
い、すなわちｋ＜１となる。そして、このｋの値は、前
記吸気孔の位置を、Ｄmin部に近い所より、吸込ベル３
の入口（直径ＤB）に近い所まで適宜選定することによ
り、容易に変え得る。FIG. 6 shows a fourth embodiment of the present invention.
The intake hole 9 is provided below the position of the minimum inner diameter Dmin of the suction bell 3 of the pump casing. The diameter of the air intake holes 9 mounting part static pressure is higher than D min portion is greater than D min, that is, k <1. The value of k is determined by setting the position of the intake hole closer to the D min portion than the suction bell 3.
Can be easily changed by appropriately selecting a point close to the entrance (diameter D B ).
【００２８】図７は、本発明の第５実施例であり、吸気
孔９の上部（下流側）のポンプケーシング内壁面に突出
部２ａを設けたものである。図８は第６実施例で、吸気
孔の下部（上流側）に突出部９ａを設けている。図７で
突出部２ａで流れがせき留められるため、そのすぐ上流
に設けた吸気孔の静圧が高くなり、ｋ＜１となる。一方
図８では、突出部９ａのすぐ下流に吸気孔が設けられて
いるため、吸気孔の静圧は低くなり、ｋ＞１となる。こ
のように、突出部の位置、大きさ、形状等を適宜選定す
ることにより、ｋの値を容易に変えることができる。FIG. 7 shows a fifth embodiment of the present invention, in which a protruding portion 2a is provided on the inner wall surface of the pump casing above (downstream) the intake hole 9. FIG. 8 shows a sixth embodiment in which a protruding portion 9a is provided at a lower portion (upstream side) of the intake hole. In FIG. 7, since the flow is dammed up by the protruding portion 2a, the static pressure of the intake hole provided immediately upstream thereof increases, and k <1. On the other hand, in FIG. 8, since the intake hole is provided immediately downstream of the protruding portion 9a, the static pressure of the intake hole is low, and k> 1. Thus, the value of k can be easily changed by appropriately selecting the position, size, shape, and the like of the protruding portion.
【００２９】このように、図２〜図８に示す方法で式
のｋの値を１.０より増減調節できるので、種々の大き
さ、比速度、全揚程のポンプに対し、従来の最低水位レ
ベルＷＬ１において、吸気孔９での静圧Ｐを大気圧Ｐｏ
と等しくなるようにすることができる。As described above, the value of k in the equation can be adjusted to be larger or smaller than 1.0 by the method shown in FIGS. 2 to 8, so that pumps of various sizes, specific speeds, and full heads can be used with the conventional minimum water level. At the level WL1, the static pressure P at the intake hole 9 is changed to the atmospheric pressure Po.
Can be made equal to
【００３０】なお、前記図２〜図８において、吸気孔の
数を羽根車の羽根数と等しくするか、それ以上、あるい
は羽根数の整数倍とし、かつ各吸気孔は、ポンプケーシ
ングの円周方向に等間隔に設けるのがよい。発明者らの
実験結果によれば、吸気孔を１個のみ設けた場合、上記
羽根車の各羽根流路に吸気孔からの空気が均一に流入し
ないため、羽根車に流体的な不つりあい力が作用し、ポ
ンプの振動が増大する現象が見られた。これに対し、吸
気孔の数を複数個、特に羽根車の羽根数と等しくするか
それ以上、あるいは羽根数の整数倍の個数設け、かつ円
周方向に等間隔に設けることにより、吸気が安定して行
われ、ポンプ羽根間に均等に空気が流入し、ポンプ振動
を低減することができる。In FIGS. 2 to 8, the number of intake holes is equal to or greater than the number of blades of the impeller, or an integral multiple of the number of blades. It is good to provide at equal intervals in the direction. According to the experimental results of the inventors, when only one intake hole is provided, the air from the intake hole does not uniformly flow into each blade flow path of the impeller, so that the fluid unbalance force is applied to the impeller. Acted, and a phenomenon that the vibration of the pump increased was observed. On the other hand, by providing a plurality of intake holes, in particular, equal to or more than the number of blades of the impeller, or by providing an integral multiple of the number of blades, and providing them at equal intervals in the circumferential direction, the intake is stabilized. In this way, air flows evenly between the pump blades, and pump vibration can be reduced.
【００３１】次に、本発明の更に他の実施例を図９〜図
１２により説明する。Next, still another embodiment of the present invention will be described with reference to FIGS.
【００３２】図９及び図１０は、立軸ポンプの羽根車１
の吸込部の吸込ベル３の内壁面よりも内側に突出して吸
気孔９を複数個設けたものである。吸気孔９は吸気管１
０により大気に開放されている。また、吸気孔９は、吸
込ベルに吸気管１０の一端に接続される開孔３ａを形成
し、かつ吸込ベル３の内壁面には前記開孔３ａと連通さ
れる。通気孔２５ａを有するリブ２５を設けて、この連
通孔２５ａを設けて、この連通孔２５ａを吸込ベル内面
よりも内側に開口させることにより形成している。前記
リブ２５は吸込ベル３と一体になるように鋳造などの手
段で製造するのが良い。また、リブ２５は図に示すよう
に、ポンプの軸方向に設けられ、吸気孔付近における旋
回流れを防止または低減する作用をする。更に、リブ２
５は、連通孔２５ａ付近から下方に伸び、その上方端の
吸込ベル内壁面からの高さは吸気孔９の開口端位置と一
致させ、該リブの下方端の高さをその上方端の高さより
も低くしたテーパ状に構成している。FIGS. 9 and 10 show an impeller 1 of a vertical shaft pump.
The suction portion has a plurality of suction holes 9 protruding inward from the inner wall surface of the suction bell 3. The intake hole 9 is the intake pipe 1
0 is open to the atmosphere. In addition, the suction hole 9 forms an opening 3a connected to one end of the suction pipe 10 in the suction bell, and the inner wall surface of the suction bell 3 communicates with the opening 3a. A rib 25 having a ventilation hole 25a is provided, the communication hole 25a is provided, and the communication hole 25a is formed by opening the communication bell 25 inside the inner surface of the suction bell. The rib 25 is preferably manufactured by means such as casting so as to be integrated with the suction bell 3. Further, as shown in the figure, the rib 25 is provided in the axial direction of the pump, and functions to prevent or reduce a swirling flow near the intake hole. Furthermore, rib 2
5 extends downward from the vicinity of the communication hole 25a, the height of the upper end from the inner wall surface of the suction bell matches the position of the opening end of the suction hole 9, and the height of the lower end of the rib is the height of the upper end. It is configured to have a tapered shape lower than that.
【００３３】本実施例では吸気孔９の開口端位置をポン
プケーシング（吸込ベル３）内壁面よりも内側にしてい
るが、その吸気孔９のケーシング内壁面からの高さをｈ
は、吸気孔位置のケーシング内壁面の半径とした時、 ｈ≧０.２Ｒ2 …… を満足するように設定するのがよい。この理由を図１１
により説明する。図１１は、ポンプ羽根車の入口部、即
ち吸気孔付近における流れの周方向の流速の大きさ（横
軸）を、ポンプケーシング内壁面から内側（ポンプケー
シング中心軸方向）に向う各ポイントごとに測定したも
ので、直線ａはポンプの流量係数が６０％以上の場合、
曲線ｂは同じく５０％の場合、曲線Ｃは同じく４０％、
曲線ｄは同じく２０％の場合である。この図から、ｒ／
Ｒ2が約０.８以下のポイントではそれが０.８以上のポ
イントに比べ周方向流速が大幅に小さくなっている。し
たがって、上記式を満足するように吸気孔９のケーシ
ング内壁面からの高さｈを決めれば旋回流速の影響を少
なくでき、旋回による遠心力も小さくなるので、十分で
安定した吸気を得ることができ、振動を低減できる。In this embodiment, the opening end position of the suction hole 9 is located inside the inner wall surface of the pump casing (suction bell 3), but the height of the suction hole 9 from the inner wall surface of the casing is h.
Is preferably set to satisfy h ≧ 0.2R 2 ... When the radius of the inner wall surface of the casing at the position of the intake hole is satisfied. The reason for this is shown in FIG.
This will be described below. FIG. 11 shows the magnitude (horizontal axis) of the flow velocity in the circumferential direction of the flow near the inlet of the pump impeller, that is, in the vicinity of the intake hole, for each point from the inner wall surface of the pump casing toward the inside (toward the central axis of the pump casing). The line a is measured when the flow coefficient of the pump is 60% or more.
Curve b is also 50%, curve C is also 40%,
Curve d is also for 20%. From this figure, r /
At the point where R 2 is about 0.8 or less, the circumferential flow velocity is much smaller than at the point where R 2 is 0.8 or more. Therefore, if the height h of the intake hole 9 from the inner wall surface of the casing is determined so as to satisfy the above expression, the influence of the swirling flow rate can be reduced, and the centrifugal force due to the swirling is reduced, so that sufficient and stable intake can be obtained. , Vibration can be reduced.
【００３４】上述した各実施例では、それぞれ吸気孔を
複数個設けているが、吸気孔の数を２以上とすることに
より安定した吸気が行われ、ポンプ振動を低減できるこ
とを図１２により説明する。図１２は、吸気孔の数とポ
ンプ振動との関係を確かめた実験データで、曲線ａは吸
込ベル内壁面上に吸気孔を１〜２０個設けた場合の振動
比の変化を示すもの、曲線ｆは上記図９の実施例で、吸
気孔の吸込ベル内壁面からの高さｈを該吸気孔位置のケ
ーシング内壁面半径Ｒ2に対し、０.２Ｒ2の位置とした
ものにおいて前記吸気孔の数を１〜２０個とした場合の
振動比の変化を示すものである。この図に示すように、
吸気孔の数を２以上とすることにより、吸気孔の数が１
のものに対し、ポンプ振動を大幅に低減できる。特に、
吸気孔の数を５以上とすることにより、ポンプ振動を極
めて小さくすることができる。この実験データなポンプ
羽根数が５枚の場合であり、吸気孔をポンプ羽根数と同
数以上として、それらを周方向に等間隔に設けることに
より、羽根間に均等に空気を流入させることができ、ポ
ンプ振動を低減できることがわかる。また、曲線ｆに示
すように、吸気孔を吸込ベル内壁面よりも内側に設けた
場合には、吸気孔の数が２つであっても、ポンプ振動を
大幅に低減できることがわかる。In each of the above-described embodiments, a plurality of intake holes are provided. However, it will be described with reference to FIG. 12 that stable intake is performed by reducing the number of intake holes to two or more, and that pump vibration can be reduced. . FIG. 12 shows experimental data obtained by confirming the relationship between the number of suction holes and pump vibration. Curve a shows a change in vibration ratio when 1 to 20 suction holes are provided on the inner surface of the suction bell. f in the embodiment of FIG. 9, the intake hole of the height h from the suction bell inner wall surface of the intake hole to the casing inner wall surface radius R 2 of the suction pores position, in that the position of the 0.2 R 2 3 shows the change in the vibration ratio when the number is 1 to 20. As shown in this figure,
By setting the number of intake holes to two or more, the number of intake holes becomes one.
, Pump vibration can be greatly reduced. In particular,
By setting the number of intake holes to 5 or more, pump vibration can be extremely reduced. This experimental data is for a case where the number of pump blades is five. By setting the number of intake holes equal to or more than the number of pump blades and providing them at equal intervals in the circumferential direction, air can be uniformly flowed between the blades. It can be seen that the pump vibration can be reduced. Also, as shown by the curve f, when the suction holes are provided inside the suction bell inner wall surface, it can be seen that even if the number of suction holes is two, the pump vibration can be significantly reduced.
【００３５】図１３及び図１４は本発明の更に他の実施
例を示すものである。この実施例はポンプケーシング４
の吸込ベル３の内壁面にテーパ状のリブ２６を設け、こ
のリブ２６に隣接して吸気孔９を２個、吸込ベル３の内
壁面上の対抗する位置に設けたものである。吸気孔９は
吸気管１０により大気に開放されている。本実施例でも
図９の実施例と同様の効果が得られる。即ち、ポンプ羽
根車１の入口部付近で旋回流れが生じても、リブ５によ
りその旋回流れを抑制できるので、吸気孔９の位置では
圧力の変動が少なくなり、安定した十分な吸気ができ、
ポンプの振動を小さくすることができる。FIGS. 13 and 14 show still another embodiment of the present invention. In this embodiment, the pump casing 4
A tapered rib 26 is provided on the inner wall surface of the suction bell 3, and two intake holes 9 are provided adjacent to the rib 26 at opposing positions on the inner wall surface of the suction bell 3. The intake hole 9 is opened to the atmosphere by an intake pipe 10. In this embodiment, the same effects as those of the embodiment of FIG. 9 can be obtained. That is, even if a swirling flow occurs near the inlet of the pump impeller 1, the swirling flow can be suppressed by the rib 5, so that the pressure fluctuation is reduced at the position of the intake hole 9 and stable and sufficient intake can be performed.
The vibration of the pump can be reduced.
【００３６】次に、上述した図９及び図１３の実施例の
動作を説明する。これらの実施例において、ポンプを低
い水位で運転すると、吸気孔９の圧力は大気圧より低下
するので、吸気管１０から吸気される。この時、吸気孔
９はポンプ羽根車入口部付近における旋回流れの影響を
受けにくい位置にあるので、圧力の変動が少なく、安定
した吸気が行える。また、旋回流れによる遠心力の影響
も小さいので、十分な吸気量が得られる。以上のことか
らポンプの振動を小さくすることができ、また吸気孔４
の下部にテーパ状のリブ５を設けることにより、吸気孔
部の補強ができ、異物がリブ５や吸気孔部に詰まらない
効果がある。Next, the operation of the embodiment shown in FIGS. 9 and 13 will be described. In these embodiments, when the pump is operated at a low water level, the pressure in the intake port 9 becomes lower than the atmospheric pressure. At this time, since the intake hole 9 is located at a position near the inlet of the pump impeller where it is hard to be affected by the swirling flow, pressure fluctuation is small and stable intake can be performed. In addition, since the influence of the centrifugal force due to the swirling flow is small, a sufficient amount of intake air can be obtained. From the above, the vibration of the pump can be reduced, and
By providing the tapered rib 5 at the lower part of the rib, the intake hole can be reinforced, and there is an effect that foreign matter does not clog the rib 5 and the intake hole.
【００３７】[0037]
【発明の効果】本発明によれば、突出部を吸気孔開口付
近のポンプケーシング内壁面に設けたことから、吸気付
近の旋回流れを防止、あるいは低減でき、吸気孔をケ−
シング内壁面上に設けなくてもよく、旋回の流れの影響
を最小限にでき、安定した吸気が行える。According to the present invention, the projection is provided with an intake hole opening.
Since provided in the pump casing wall of the near, preventing the turning flow in the vicinity of the intake, or can at reduced, the suction holes Ke -
It does not need to be provided on the inner wall surface of the shing, the influence of the turning flow can be minimized, and stable intake can be performed.
【００３８】また、本発明においては、前述のように吸
気管の大気への開口部を、吸水槽の最高水位より高い位
置に設けているので、開口部に、吸水槽内の水に浮遊す
るゴミ等の異物が吸着し、水位低下時の吸気作用が阻害
されるということが起こらない。Further, in the present invention, since the opening of the intake pipe to the atmosphere is provided at a position higher than the maximum water level of the water absorption tank as described above, it floats in the water in the water absorption tank at the opening. It does not occur that foreign substances such as dust are adsorbed and the intake action at the time of lowering the water level is hindered.
【００３９】[0039]
【００４０】[0040]
【００４１】[0041]
【図面の簡単な説明】[Brief description of the drawings]
【図１】本発明が適用される立軸ポンプの全体側面図。FIG. 1 is an overall side view of a vertical shaft pump to which the present invention is applied.
【図２】本発明の第１の実施例を示す要部の詳細縦断面
図。FIG. 2 is a detailed vertical sectional view of a main part showing the first embodiment of the present invention.
【図３】本発明の第２の実施例を示す要部の詳細縦断面
図。FIG. 3 is a detailed vertical sectional view of a main part showing a second embodiment of the present invention.
【図４】本発明の第３の実施例を示す要部の詳細縦断面
図。FIG. 4 is a detailed vertical sectional view of a main part showing a third embodiment of the present invention.
【図５】図４の吸気孔の方向（角度α°）と上記式の
定数ｋとの関係を示す線図。5 is a diagram showing the relationship between the direction (angle α °) of an intake hole in FIG. 4 and a constant k in the above equation.
【図６】本発明の第４実施例を示す要部の詳細縦断面
図。FIG. 6 is a detailed vertical sectional view of a main part showing a fourth embodiment of the present invention.
【図７】本発明の第５実施例を示す要部の詳細縦断面
図。FIG. 7 is a detailed vertical sectional view of a main part showing a fifth embodiment of the present invention.
【図８】本発明の第６実施例を示す要部の詳細縦断面
図。FIG. 8 is a detailed vertical sectional view of a main part showing a sixth embodiment of the present invention.
【図９】本発明の第７の実施例を示す要部の詳細縦断面
図。FIG. 9 is a detailed vertical sectional view of a main part showing a seventh embodiment of the present invention.
【図１０】図９のＸ−Ｘ線矢視図。FIG. 10 is a view taken along line XX of FIG. 9;
【図１１】ポンプ羽根車入口部付近における流れの周方
向流速を半径方向各点で測定して示した線図。FIG. 11 is a diagram showing the circumferential flow velocity of the flow near the inlet of the pump impeller measured at each point in the radial direction.
【図１２】吸気孔の数とポンプ振動との関係を示す線
図。FIG. 12 is a diagram showing a relationship between the number of intake holes and pump vibration.
【図１３】本発明の第８実施例を示す要部の詳細縦断面
図。FIG. 13 is a detailed vertical sectional view of a main part showing an eighth embodiment of the present invention.
【図１４】図１３のＹ−Ｙ線矢視図。FIG. 14 is a view taken along the line YY in FIG. 13;
１…羽根車、２…ケーシングライナ、３…吸込ベル、４
…ポンプケーシング、５…揚水管、６…吐出エルボ、７
…吐出管、８…吐出弁、９…吸気孔、１０…吸気管、１
１…吸気量調整弁、１２…吸込口、２０…吸水槽、２
５，２６…リブ。DESCRIPTION OF SYMBOLS 1 ... Impeller, 2 ... Casing liner, 3 ... Suction bell, 4
... pump casing, 5 ... water pipe, 6 ... discharge elbow, 7
... discharge pipe, 8 ... discharge valve, 9 ... intake hole, 10 ... intake pipe, 1
DESCRIPTION OF SYMBOLS 1 ... Intake amount adjustment valve, 12 ... Suction port, 20 ... Water absorption tank, 2
5, 26 ... rib.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 実開 平１−76588（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) F04D 13/00 F04D 29/54 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-U 1-76588 (JP, U) (58) Fields surveyed (Int. Cl. 7 , DB name) F04D 13/00 F04D 29/54
Claims (1)
吸込ベルより空気を吸い込んでしまう最低水位レベルに
相当する位置より下方にポンプの羽根車を位置させ、こ
の羽根車の下方のポンプケーシングに吸気孔を設け、こ
の吸気孔に吸気管の一端を接続すると共に、その他端を
ポンプ吸水槽の最高水位より高いレベルにて大気に開放
させ、かつ前記吸気孔開口付近に該吸気孔開口位置より
も内方に突出させて前記ポンプケーシング内壁面に突出
部を設けたことを特徴とする立軸ポンプ。1. When the water level during the operation of the pump is below,
The pump impeller is located below the position corresponding to the lowest water level at which air is sucked from the suction bell, and an intake hole is provided in the pump casing below the impeller, and one end of the intake pipe is connected to this intake hole. At the same time, the other end is opened to the atmosphere at a level higher than the highest water level of the pump suction tank, and near the intake hole opening, from the intake hole opening position.
A vertical shaft pump wherein a protrusion is provided on an inner wall surface of the pump casing so as to protrude inward .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23617096A JP2997874B2 (en) | 1996-09-06 | 1996-09-06 | Vertical pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23617096A JP2997874B2 (en) | 1996-09-06 | 1996-09-06 | Vertical pump |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22918689A Division JP2881197B2 (en) | 1989-04-19 | 1989-09-06 | Vertical pump |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09105394A JPH09105394A (en) | 1997-04-22 |
| JP2997874B2 true JP2997874B2 (en) | 2000-01-11 |
Family
ID=16996816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23617096A Expired - Lifetime JP2997874B2 (en) | 1996-09-06 | 1996-09-06 | Vertical pump |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2997874B2 (en) |
-
1996
- 1996-09-06 JP JP23617096A patent/JP2997874B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09105394A (en) | 1997-04-22 |
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