GB1559868A - Surface aerator for liquids - Google Patents
Surface aerator for liquids Download PDFInfo
- Publication number
- GB1559868A GB1559868A GB39454/76A GB3945476A GB1559868A GB 1559868 A GB1559868 A GB 1559868A GB 39454/76 A GB39454/76 A GB 39454/76A GB 3945476 A GB3945476 A GB 3945476A GB 1559868 A GB1559868 A GB 1559868A
- Authority
- GB
- United Kingdom
- Prior art keywords
- aerator
- channels
- guide wall
- exit ends
- blades
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/02—Aerobic processes
- C02F3/12—Activated sludge processes
- C02F3/14—Activated sludge processes using surface aeration
- C02F3/16—Activated sludge processes using surface aeration the aerator having a vertical axis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
- B01F23/20—Mixing gases with liquids
- B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
- B01F23/234—Surface aerating
- B01F23/2342—Surface aerating with stirrers near to the liquid surface, e.g. partially immersed, for spraying the liquid in the gas or for sucking gas into the liquid, e.g. using stirrers rotating around a horizontal axis or using centrifugal force
- B01F23/23421—Surface aerating with stirrers near to the liquid surface, e.g. partially immersed, for spraying the liquid in the gas or for sucking gas into the liquid, e.g. using stirrers rotating around a horizontal axis or using centrifugal force the stirrers rotating about a vertical axis
- B01F23/234211—Stirrers thereof
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biodiversity & Conservation Biology (AREA)
- Microbiology (AREA)
- Hydrology & Water Resources (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Dry Development In Electrophotography (AREA)
- Mixers Of The Rotary Stirring Type (AREA)
Description
(54) A SURFACE AERATOR FOR LIQUIDS
(71) We, NORM A.M.C.
AKTIENGESELLSCHAFT, a joint stock company organized under the laws of
Switzerland of Schulhausstrasse 10 CH6048, HORWILU, Switzerland, do hereby declare this invention for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement:- This invention relates to a surface aerator for liquids, particularly for wastewater to be purified, of the general kind having a body arranged for rotation about a vertical axis, the body having at least one array of blades diverging from a lower suction opening towards an upper discharge opening, whereby the blade array forms a number of conveying channels directed in such a manner that the liquid entering the channels from the suction opening is diverted through substantially 90" and is discharged at the circumference of the rotor in a generally radial direction.
It is known that the overall effectiveness of a surface aerator depends not only upon its capability to achieve intimate contact between the projected liquid and the overhead gas, but also upon its ability to produce strong mixing currents within the body of liquid. In the past, surface aerators which achieve excellent gas-liquid contact have been incapable of circulating liquid at sufficient rate to transfer the total required quantity of oxygen and to distribute the dissolved oxygen uniformly throughout the liquid body. Surface aerators which have possessed the desired liquid circulating capability have obtained poor contact between the projected liquid and the overhead gas. As a result, previous surface aerators have not achieved high dissolution performance per unit drive power.
It is known that in order to obtain good oxygen dissolution performance per KW drive power, waste-water surface aerators should expel the water at high rate over the surface of the body of water. It is also important that the aerator produce rapid recirculation and mixing of substantially all the water within the tank, so that the water thrown upward in contact with the gas will not already be highly enriched with dissolved oxygen, but instead will contain the lowest dissolved oxygen concentration of all the liquid in the tank. Such "liquid mixing" function is important in order to maximize the concentration driving force for oxygen dissolution, and in order to distribute the dissolved oxygen effectively to all regions of the tank.
An object of the invention is to provide a surface aerator of the above general kind which does not have the above named disadvantages and, which, with the same dimensions as known surface aerators, achieves a higher oxygen dissolution performance per unit drive power.
According to this invention, a surface aerator for the aeration of liquids comprises a body arranged for rotation about a vertical axis, the body being hollow and diverging from a lower suction opening towards an upper discharge opening, the body carrying at least one array of blades, each blade having at least one portion fixed to and extending away from the interior surface of the body and a further portion generally transverse to said one portion and spaced from and overlying said surface so that the blades and said surface define conveying channels which are open towards the interior of the body and directed in such a manner that the liquid entering these channels from the suction opening is diverted through substantially 900 and discharges at the circumference of the rotor in a generally radial direction, the ratio of the aerator outer diameter measured so as to exclude the width of an outer generally radial flow guide wall, to the suction opening diameter lying in the range between 1.3 to 1.7, and the ratio of the aerator outer diameter to the height of the aerator measured from the suction opening to said surface at the exit ends of the channels, lying in the range between 2.5 to 5.5.
Surface aerators designed in accordance with this invention possess high liquid recirculation capability despite the fact that the liquid acceleration channels between the blades are greatly shortened in length, as compared with some conventional aerators of the aforesaid general kind as a result of enlarging the inlet and reducing the height
H. Moreover, the rate of curvature of the channels, from vertical orientation at the inlet to the substantially horizontal orientation at the outlet, is made much more rapid and acute in the surface aerators of this invention.
In operation, surface aerators of this invention are observed to impose no appreciable rotary motion to the liquid within the inlet zone, i.e., inside the wreath of rotating blades. The liquid motion at the inlet is primarily vertical, upward into the channels between the blades and there is no discernable vortex.
The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of the surface aerator of the invention;
Figure 2 is a perspective view, partially in cut-away, of a second embodiment of the surface aerator of the invention;
Figure 3 is vertical section through a further embodiment of the surface aerator of the invention; and
Figure 4 is a section along the line IV-IV in Figure 3.
The surface aerator represented in Figure 1 has a rotatable body 2 diverging from the lower suction side towards the upper exit side and carrying an array of blades 1, the array of blades thus forming a number of conveying channels 3 curved in vertical planes. By this means, the liquid entering the conveying channels 3 from the bottom is diverted by about 900 in these channels and exits at the circumference of the rotor in a horizontal direction.
For the formation of the conveying channels 3, which are open towards the interior, the blades 4 have an L-shaped profile, the free longitudinal edges of the vertical portions 5 of the L-shaped profiles being fastened to the inside of the rotational body 2.
On the upper side of the blades 4a, 4b and 4c, is fastened a support 6 which serves to connect the rotor with the drive shaft 7.
This surface aerator is intended to operate only in the direction indicated by arrow 8.
By contrast with the surface aerator represented in Figure 1, the surface aerator depicted in Figure 2 uses blades 4 with Tshaped cross-sections for the formation of conveying channels which are open towards the interior, the free longitudinal edges of the vertical portion 5 of the T-shaped profiles being fastened to the inside of the rotational body 2. The surface aerator of
Figure 2 is meant to be driven in either direction of rotation.
In order to obtain high oxygen dissolution performance per unit of driving power, the ratio of the outer diameter of the surface aerator A (see Figure 2, measured without the width b of the guide wall 10) to the suction inlet diameter C lies in the range between 1.3 to 1.7 and is preferably 1.48.
The ratio of the outer diameter of the aerator A (measured without the width b of the flow guide wall 10) to the height H of the aerator from the underside of the aerator to the underside of the exit cross-sectional area 9 lies in the range between 2.5 to 5.5 and preferably is 3.7.
In order to convey the liquid leaving the surface aerator in a flat and more concentrated fashion over the surface area to be aerated, this embodiment is advantageously provided, along the underside of the -exits 9 of the conveying channels 3, with an annular flow guide wall 10 running concentric to the aerator axis and extending radially outwardly from the channel exits 9. It was found to be advantageous for the width b of the ringshaped guide wall 10 to be at least 70%, preferably 100% of the height h of the channel exits 9.
By arranging the annular flow guide wall 10 along the underside of the exits 9 of the conveying channel 3, the waste-water exiting from the latter is prevented from impinging immediately after leaving the conveying channel exits 9 against the surrounding liquid. Due to the action of the ring-shaped flow guide wall 10, the liquid leaving the conveying channels 3 is conveyed in a flat and broad manner above the liquid surface area which surrounds the surface aerator.
It was found to be advantageous if the angle of emersion (cur) of the blades lies in the range of 10 to 350 and if the radius of curvature r of the vertical portions 5 of the blade profiles, as seen from an axial direction, correspond to the aerator outer diameter A (measured without the width b of the flow guide wall) with a deviation of + 10%.
The surface aerator represented in Figure 3 and Figure 4 is equipped additionally with a further flow guide wall 11 which is arranged above the exits 9 of the conveying channels 3 concentric to the axis of the aerator and extending radially outward from the channel exits 9. By this means, the liquid leaving the conveying channels 3 is conveyed in a very flat manner above the water surface.
Claims (11)
1. A surface aerator for the aeration of liquids, comprising a body arranged for rotation about a vertical axis, the body being hollow and diverging from a lower suction opening towards an upper discharge opening, the body carrying at least one array of blades, each blade having at least one portion fixed to and extending away from the interior surface of the body and a further portion generally transverse to said one portion and spaced from and overlying said surface so that the blades and said surface define conveying channels which are open towards the interior of the body and directed in such a manner that the liquid entering these channels from the suction opening is diverted through substantially 90" and discharges at the circumference of the rotor in a generally radial direction, the ratio of the aerator outer diameter measured so as to exclude the width of an outer generally radial flow guide wall to the suction opening diameter lying in the range between 1.3 to 1.7, and the ratio of the aerator outer diameter to the height of the aerator measured from the suction opening to said surface at the exit ends of the channels, lying in the range between 2.5 to 5.5.
2. A surface aerator according to Claim I wherein the flow guide wall is annular and disposed around the exit ends of the conveying channels at the level of said surface, said guide wall being concentric to the axis of the aerator and extending radially outwardly from said exit ends.
3. A surface aerator according to Claim 2 wherein the width of the annular flow guide wall is at least 70% of the height of the exit ends of the channels.
4. A surface aerator according to Claim 1 wherein a further flow guide wall is disposed around the axially outermost extremities of the exit ends of the conveying channels, said further guide wall being concentric to the axis of the aerator and extending radially outwardly from the exit ends of the channels.
5. A surface aerator according to any one of Claims 1 to 4 wherein the angle of emersion (a) of the blades lies in the range of 10 to 350.
6. A surface aerator according to any one of Claims 1 to 5 wherein the radius of curvature of the blades as seen from an axial direction, corresponds to the outer diameter of the aerator, with a deviation of + 10%.
7. A surface aerator according to Claim 3 wherein the width of the annular flow guide wall is equal to the height of the exit ends of the channels.
8. A surface aerator according to Claim 1, wherein said ratio of the aerator outer diameter measured so as to exclude the width of said flow guide wall, to the suction opening diameter is 1.48.
9. A surface aerator according to Claim I wherein the ratio of the aerator outer diameter to the height of the aerator measured from the suction opening to said surface at said exit ends of the channels is 3.7.
10. A surface aerator according to any one of the preceding claims wherein each of the blades has an "L" or "r' shaped end profile when viewed from the periphery of the aerator.
11. A surface aerator substantially as hereinbefore described with reference to
Figure 1, Figure 2, or Figures 3 and 4 of the accompanying drawings.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH1240175A CH591278A5 (en) | 1975-09-24 | 1975-09-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1559868A true GB1559868A (en) | 1980-01-30 |
Family
ID=4382655
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB39454/76A Expired GB1559868A (en) | 1975-09-24 | 1976-09-23 | Surface aerator for liquids |
Country Status (19)
Country | Link |
---|---|
JP (1) | JPS5241446A (en) |
AT (1) | AT343063B (en) |
AU (1) | AU1799976A (en) |
BR (1) | BR7606400A (en) |
CH (1) | CH591278A5 (en) |
CS (1) | CS189034B2 (en) |
DD (1) | DD126165A5 (en) |
DE (1) | DE2559170C2 (en) |
EG (1) | EG12940A (en) |
ES (1) | ES451802A1 (en) |
FR (1) | FR2325610A1 (en) |
GB (1) | GB1559868A (en) |
IE (1) | IE43724B1 (en) |
IT (1) | IT1075245B (en) |
MX (1) | MX3697E (en) |
NL (1) | NL7610424A (en) |
PL (1) | PL110638B1 (en) |
TR (1) | TR19499A (en) |
ZA (1) | ZA765661B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017051405A1 (en) * | 2015-09-24 | 2017-03-30 | O2 Waterator Ltd. | Centrifugal aerator |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5828822B2 (en) * | 1978-01-23 | 1983-06-18 | 三立電機株式会社 | switching regulator |
JPS5857068B2 (en) * | 1978-04-28 | 1983-12-17 | ティーディーケイ株式会社 | Switching power supply control method |
DE4221845C2 (en) * | 1992-07-03 | 1996-02-22 | Sondia Holding Ag | Process for aerating liquid, surface aeration gyro to carry out the method and use of the surface aeration gyro |
JP5758345B2 (en) * | 2012-05-09 | 2015-08-05 | 住友重機械エンバイロメント株式会社 | Impeller |
JP7426271B2 (en) * | 2020-03-27 | 2024-02-01 | 住友重機械エンバイロメント株式会社 | impeller |
CN113854231B (en) * | 2021-10-15 | 2022-11-18 | 中国水产科学研究院 | Efficient and energy-saving aerator for aquaculture and working method |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH443165A (en) * | 1964-02-27 | 1967-08-31 | Kaelin J R | Device for circulating and aerating water r |
CH463409A (en) * | 1968-05-28 | 1968-09-30 | Kaelin J R | Surface aerators for circulating and aerating liquids, in particular for waste water purification systems |
CH478719A (en) * | 1968-11-28 | 1969-09-30 | Kaelin J R | Vertical-axis aerator for aerating liquids, especially wastewater to be treated |
CH495293A (en) * | 1969-05-19 | 1970-08-31 | Kaelin J R | Vertical axis aerator for aerating liquids |
DE2240847A1 (en) * | 1972-08-19 | 1974-02-28 | Koppers Gmbh Heinrich | Surface aeration impeller - with extension flaps hinged to blades for angle of incidence adjustment |
-
1975
- 1975-09-24 CH CH1240175A patent/CH591278A5/xx not_active IP Right Cessation
- 1975-12-30 DE DE2559170A patent/DE2559170C2/en not_active Expired
-
1976
- 1976-09-20 NL NL7610424A patent/NL7610424A/en not_active Application Discontinuation
- 1976-09-20 IE IE2075/76A patent/IE43724B1/en unknown
- 1976-09-21 AT AT700576A patent/AT343063B/en not_active IP Right Cessation
- 1976-09-21 ZA ZA765661A patent/ZA765661B/en unknown
- 1976-09-21 EG EG57376A patent/EG12940A/en active
- 1976-09-22 AU AU17999/76A patent/AU1799976A/en not_active Expired
- 1976-09-22 IT IT960076A patent/IT1075245B/en active
- 1976-09-22 CS CS613876A patent/CS189034B2/en unknown
- 1976-09-23 ES ES451802A patent/ES451802A1/en not_active Expired
- 1976-09-23 PL PL1976192599A patent/PL110638B1/en unknown
- 1976-09-23 GB GB39454/76A patent/GB1559868A/en not_active Expired
- 1976-09-23 FR FR7628669A patent/FR2325610A1/en not_active Withdrawn
- 1976-09-24 TR TR1949976A patent/TR19499A/en unknown
- 1976-09-24 MX MX10038576U patent/MX3697E/en unknown
- 1976-09-24 JP JP11458376A patent/JPS5241446A/en active Granted
- 1976-09-24 DD DD19498276A patent/DD126165A5/xx unknown
- 1976-09-24 BR BR7606400A patent/BR7606400A/en unknown
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017051405A1 (en) * | 2015-09-24 | 2017-03-30 | O2 Waterator Ltd. | Centrifugal aerator |
CN108290125A (en) * | 2015-09-24 | 2018-07-17 | O2瓦特雷德有限公司 | Centrifuge aerator |
Also Published As
Publication number | Publication date |
---|---|
EG12940A (en) | 1980-03-31 |
IT1075245B (en) | 1985-04-22 |
JPS561157B2 (en) | 1981-01-12 |
CS189034B2 (en) | 1979-03-30 |
MX3697E (en) | 1981-05-08 |
ATA700576A (en) | 1977-08-15 |
TR19499A (en) | 1979-03-29 |
ES451802A1 (en) | 1977-11-01 |
AT343063B (en) | 1978-05-10 |
AU1799976A (en) | 1978-04-06 |
NL7610424A (en) | 1977-03-28 |
DE2559170C2 (en) | 1984-08-30 |
IE43724L (en) | 1977-03-24 |
CH591278A5 (en) | 1977-09-15 |
PL110638B1 (en) | 1980-07-31 |
IE43724B1 (en) | 1981-05-06 |
FR2325610A1 (en) | 1977-04-22 |
JPS5241446A (en) | 1977-03-31 |
DD126165A5 (en) | 1977-06-22 |
DE2559170A1 (en) | 1977-03-31 |
ZA765661B (en) | 1977-08-31 |
BR7606400A (en) | 1977-05-31 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |