[go: up one dir, main page]

GB2056870A - Method of agitating liquids - Google Patents

Method of agitating liquids Download PDF

Info

Publication number
GB2056870A
GB2056870A GB7920206A GB7920206A GB2056870A GB 2056870 A GB2056870 A GB 2056870A GB 7920206 A GB7920206 A GB 7920206A GB 7920206 A GB7920206 A GB 7920206A GB 2056870 A GB2056870 A GB 2056870A
Authority
GB
United Kingdom
Prior art keywords
liquid
slurry
mixing
bladder
gas
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.)
Withdrawn
Application number
GB7920206A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Water Research Centre
Original Assignee
Water Research Centre
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Water Research Centre filed Critical Water Research Centre
Priority to GB7920206A priority Critical patent/GB2056870A/en
Publication of GB2056870A publication Critical patent/GB2056870A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • C02F3/02Aerobic processes
    • C02F3/12Activated sludge processes
    • C02F3/1278Provisions for mixing or aeration of the mixed liquor
    • C02F3/1284Mixing devices
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F31/00Mixers with shaking, oscillating, or vibrating mechanisms
    • B01F31/65Mixers with shaking, oscillating, or vibrating mechanisms the materials to be mixed being directly submitted to a pulsating movement, e.g. by means of an oscillating piston or air column
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F33/00Other mixers; Mixing plants; Combinations of mixers
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00Technologies for wastewater treatment
    • Y02W10/10Biological treatment of water, waste water, or sewage

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Microbiology (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Treatment Of Sludge (AREA)

Abstract

Liquids and slurries, such as water treatment sludges, are agitated to cause mixing by periodic inflation and deflation of an inflatable body 1, such as an electric- walled bladder, immersed in the liquid or slurry. The bladder 1 may be anchored or it may be free to rise and fall, with inflation and deflation respectively, which contributes to the mixing effect. <IMAGE>

Description

SPECIFICATION Method of agitating liquids This invention relates to a method of agitating a volume of a liquid or slurry to cause mixing thereof.
In various processes involving the use of a liquid or slurry (such as a sludge), it is necessary or at least desirable to keep the liquid or slurry well mixed. For example, in sewage treatment, it is essential to have thorough mixing of sludge in digestion tanks for the treatment process to be efficient. Various techniques are known for effecting mixing in a volume of liquid or slurry. Most commonly, rotational mechanical stirrers or recirculation pumps are used. These cause agitation within the liquid or slurry and so cause mixing.
Another technique involves injecting a gas into the liquid or slurry, the rising gas bubbles creating the desired mixing.
In many cases, the provision and operating costs of mechanical stirrers and recirculation pumps are high and they do not always achieve satisfactory mixing. The injection of gas can be difficult in practice to control and can lead to undesirable volatalisation and entrainment of gas bubbles.
We have now devised a method of mixing a liquid or a slurry by which at least some of the disadvantages of prior known methods can be reduced or avoided.
According to the present invention, there is provided a method of agitating a volume of liquid or slurry to cause mixing thereof which comprises immersing in the liquid or slurry an inflatable body, and periodically inflating and deflating the body to increase and decrease its volume, respectively, to cause agitation and hence mixing of the liquid or slurry.
The inflatable body is preferably an elasticwalled bladder. The precise shape may vary, but we prefer to use an elongate tubular bladder. A gas supply line is provided to inflate the bladder. To deflate the immersed bladder, the gas may simply be vented into the liquid or slurry. We prefer, however, to avoid direct contact between the gas and the liquid or slurry, and for this purpose the gas is preferably ducted away from the bladder out of contact with the liquid or slurry.
The inflatable body causes movement and, thus, mixing of the liquid or slurry as it is inflated and deflated. The body may be held stationary in the liquid or slurry or, alternatively, it may be moved around. According to a preferred feature of the invention, the inflatable body is so weighted that, upon inflation, it rises within the liquid and upon deflation it sinks. In this way, there is an extra stirring effect due to the rise and fall of the body as it is successively inflated and deflated.
In order that the invention may be more fully understood, reference is made to the accompanying drawing which shows, in longitudinal cross-section, one form of inflatable body of the invention. Referring to the drawing, the body comprises an elongate cylindrical rubber bladder 1 (shown partly inflated), having a metal tube 2 passing therethrough with a flange 3 at each end. Th ends of the bladder 1 are compressed against flanges 3 by washers 4, to make air-tight joints. One end flange 3 is provided with a gas passage 5 for the supply and removal of gas from the inside 6 of bladder 1.
In use, a source of gas under pressure is connected to passage 5, and the body is immersed in a liquid or slurry. If it is desired to have the body rise and fall with inflation/ deflation, its weight has to be appropriate to the particular liquid or slurry and extra weights can be attached to the body as necessary. Gas supplied under pressure to passage 5 will cause inflation of the bladder. By suitable valving arrangements (not shown), passage 5 can then be disconnected from the gas pressure source and the bladder vented to cause deflation. The expansion and contraction of the bladder in the liquid or slurry causes mixing thereof. The mixing effect is greater if the bladder is also allowed to rise and fall within the liquid or slurry.
As will be clear to those skilled in the art, the inflatable body can be of almost size and shape, as required by the proposed use. Thus, inflatable bodies can be made for use with mixing vessels ranging from 1 litre up to 100 m3 volume. By way of experiment, an inflatable body closely similar to that illustrated has been used successfully to overcome the settling of sewage sludge solids in sludge storage tanks of 3.5 m depth and 20 m3 capacity.
Whilst the method of the invention is particularly useful in the water and sewage treatment industries, for mixing sludges, it is also useful in other fields, for example for keeping solids in suspension in liquids or generally for maintaining liquid-containing mixtures in a homogenous state.
1. A method of agitating a volume of liquid or slurry to cause mixing thereof, which comprises periodically inflating and deflating an inflatable body immersed in the liquid or slurry, to increase and decrease the volume of the body and thereby cause agitation of the liquid or slurry.
2. A method according to claim 1 wherein the inflated body is deflated by removing gas therefrom without contact between the gas and the liquid or slurry.
3. A method according to claim 1 or 2 wherein the body is held stationary in the liquid or slurry.
4. A method accoding to claim 1 or 2 wherein the body is free to rise and sink
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method of agitating liquids This invention relates to a method of agitating a volume of a liquid or slurry to cause mixing thereof. In various processes involving the use of a liquid or slurry (such as a sludge), it is necessary or at least desirable to keep the liquid or slurry well mixed. For example, in sewage treatment, it is essential to have thorough mixing of sludge in digestion tanks for the treatment process to be efficient. Various techniques are known for effecting mixing in a volume of liquid or slurry. Most commonly, rotational mechanical stirrers or recirculation pumps are used. These cause agitation within the liquid or slurry and so cause mixing. Another technique involves injecting a gas into the liquid or slurry, the rising gas bubbles creating the desired mixing. In many cases, the provision and operating costs of mechanical stirrers and recirculation pumps are high and they do not always achieve satisfactory mixing. The injection of gas can be difficult in practice to control and can lead to undesirable volatalisation and entrainment of gas bubbles. We have now devised a method of mixing a liquid or a slurry by which at least some of the disadvantages of prior known methods can be reduced or avoided. According to the present invention, there is provided a method of agitating a volume of liquid or slurry to cause mixing thereof which comprises immersing in the liquid or slurry an inflatable body, and periodically inflating and deflating the body to increase and decrease its volume, respectively, to cause agitation and hence mixing of the liquid or slurry. The inflatable body is preferably an elasticwalled bladder. The precise shape may vary, but we prefer to use an elongate tubular bladder. A gas supply line is provided to inflate the bladder. To deflate the immersed bladder, the gas may simply be vented into the liquid or slurry. We prefer, however, to avoid direct contact between the gas and the liquid or slurry, and for this purpose the gas is preferably ducted away from the bladder out of contact with the liquid or slurry. The inflatable body causes movement and, thus, mixing of the liquid or slurry as it is inflated and deflated. The body may be held stationary in the liquid or slurry or, alternatively, it may be moved around. According to a preferred feature of the invention, the inflatable body is so weighted that, upon inflation, it rises within the liquid and upon deflation it sinks. In this way, there is an extra stirring effect due to the rise and fall of the body as it is successively inflated and deflated. In order that the invention may be more fully understood, reference is made to the accompanying drawing which shows, in longitudinal cross-section, one form of inflatable body of the invention. Referring to the drawing, the body comprises an elongate cylindrical rubber bladder 1 (shown partly inflated), having a metal tube 2 passing therethrough with a flange 3 at each end. Th ends of the bladder 1 are compressed against flanges 3 by washers 4, to make air-tight joints. One end flange 3 is provided with a gas passage 5 for the supply and removal of gas from the inside 6 of bladder 1. In use, a source of gas under pressure is connected to passage 5, and the body is immersed in a liquid or slurry. If it is desired to have the body rise and fall with inflation/ deflation, its weight has to be appropriate to the particular liquid or slurry and extra weights can be attached to the body as necessary. Gas supplied under pressure to passage 5 will cause inflation of the bladder. By suitable valving arrangements (not shown), passage 5 can then be disconnected from the gas pressure source and the bladder vented to cause deflation. The expansion and contraction of the bladder in the liquid or slurry causes mixing thereof. The mixing effect is greater if the bladder is also allowed to rise and fall within the liquid or slurry. As will be clear to those skilled in the art, the inflatable body can be of almost size and shape, as required by the proposed use. Thus, inflatable bodies can be made for use with mixing vessels ranging from 1 litre up to 100 m3 volume. By way of experiment, an inflatable body closely similar to that illustrated has been used successfully to overcome the settling of sewage sludge solids in sludge storage tanks of 3.5 m depth and 20 m3 capacity. Whilst the method of the invention is particularly useful in the water and sewage treatment industries, for mixing sludges, it is also useful in other fields, for example for keeping solids in suspension in liquids or generally for maintaining liquid-containing mixtures in a homogenous state. CLAIMS
1. A method of agitating a volume of liquid or slurry to cause mixing thereof, which comprises periodically inflating and deflating an inflatable body immersed in the liquid or slurry, to increase and decrease the volume of the body and thereby cause agitation of the liquid or slurry.
2. A method according to claim 1 wherein the inflated body is deflated by removing gas therefrom without contact between the gas and the liquid or slurry.
3. A method according to claim 1 or 2 wherein the body is held stationary in the liquid or slurry.
4. A method accoding to claim 1 or 2 wherein the body is free to rise and sink within the liquid or slurry, and wherein upon inflation the body rises and upon deflation the body sinks.
5. A method according to any of claims 1 to 4 wherein the body comprises an elongate elastic-walled bladder.
6. A method of agitating a volume of liquid or slurry substantially as herein described with reference to the accompanying drawing.
GB7920206A 1979-06-11 1979-06-11 Method of agitating liquids Withdrawn GB2056870A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7920206A GB2056870A (en) 1979-06-11 1979-06-11 Method of agitating liquids

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7920206A GB2056870A (en) 1979-06-11 1979-06-11 Method of agitating liquids

Publications (1)

Publication Number Publication Date
GB2056870A true GB2056870A (en) 1981-03-25

Family

ID=10505761

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7920206A Withdrawn GB2056870A (en) 1979-06-11 1979-06-11 Method of agitating liquids

Country Status (1)

Country Link
GB (1) GB2056870A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2531901A1 (en) * 1982-08-19 1984-02-24 Hudelmaier Ingrid CONCRETE MIXER EQUIPPED WITH A VIBRATOR
CN104190306A (en) * 2014-06-10 2014-12-10 苏州培英实验设备有限公司 Novel auto-mixing shake flask
CN108751453A (en) * 2018-06-20 2018-11-06 佛山市宝粤美科技有限公司 Utilize hydraulic pressure gas explosion oxygenate apparatus and application method
CN114950315A (en) * 2022-05-13 2022-08-30 河北彩客新材料科技股份有限公司 Stirring reation kettle is used in DATA production
CN118047144A (en) * 2024-04-12 2024-05-17 河南农心肥业有限公司 Material storage system for preventing material caking based on sealed feeding

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2531901A1 (en) * 1982-08-19 1984-02-24 Hudelmaier Ingrid CONCRETE MIXER EQUIPPED WITH A VIBRATOR
CN104190306A (en) * 2014-06-10 2014-12-10 苏州培英实验设备有限公司 Novel auto-mixing shake flask
CN108751453A (en) * 2018-06-20 2018-11-06 佛山市宝粤美科技有限公司 Utilize hydraulic pressure gas explosion oxygenate apparatus and application method
CN114950315A (en) * 2022-05-13 2022-08-30 河北彩客新材料科技股份有限公司 Stirring reation kettle is used in DATA production
CN114950315B (en) * 2022-05-13 2023-09-05 河北彩客新材料科技股份有限公司 Stirring reaction kettle for DATA production
CN118047144A (en) * 2024-04-12 2024-05-17 河南农心肥业有限公司 Material storage system for preventing material caking based on sealed feeding
CN118047144B (en) * 2024-04-12 2024-07-23 河南农心肥业有限公司 Material storage system for preventing material caking based on sealed feeding

Similar Documents

Publication Publication Date Title
US5587114A (en) Aeration system employing retrievable aeration modules
GB2056870A (en) Method of agitating liquids
US2797903A (en) Contacting vessel
CN116161807B (en) Sewage pool aeration device
US4008155A (en) Apparatus for disposal of effluents
US6837994B2 (en) Water treatment apparatus
US4171263A (en) Pressurized oxygenation of sewage
BR0208341B1 (en) Method for anaerobic sludge purification, and device for anaerobic sludge purification containing organic constituents.
US2715099A (en) Walking beam flocculator-aerator
CN213595977U (en) A kind of aeration equipment for aeration tank for river sewage treatment
JP2000325995A (en) Organic sludge ozonation equipment
US3649531A (en) Dewatering of digested sludge
Eckenfelder et al. Engineering aspects of surface aeration design
US3772163A (en) Electrochemical processing of inner surfaces of large vessels
KR100381575B1 (en) Plant for efficiency effluent of dissolved matter from the wastewater separated into solids and dissolved matter
KR101022542B1 (en) Liquid, liquid, liquid, and gas micromixers
RU2056372C1 (en) Aerator
JP2002204938A (en) Submerged agitator and agitation apparatus
KR100506037B1 (en) Apparatus for disposing waste water
JPH10156386A (en) Purifying tank
KR101835767B1 (en) Water treatment system including enclosed reactor for denitrification efficiency
CN116102160B (en) Liftable aeration assembly and biochemical sewage treatment reactor
US4963252A (en) Decanter device
JP4011431B2 (en) Ozone treatment method
JPH01284317A (en) Filtration concentrator

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)