US4244749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonic cleaning method and apparatus for heat exchangers
Assignee: Johns Hopkins University
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Filing: 1978-11-24
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Granted: 1981-01-13
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Expires: 1998-11-24
Abstract
Abstract Biofouling is removed from the external surfaces of spaced apart pipes of a heat exchanger which are in contact with a liquid by positioning a plurality of ultrasonic transducers between the pipes and operating the transducers at sufficient power levels to cause cavitation within the liquid to effect the desired cleaning action. The transducers are arranged in a planar configuration to produce bi-directional acoustic radiation. Various types of instrumentation are provided for determining extent of biofouling and effectiveness of cleaning as well as for monitoring transducer operating parameters.
Inventors
- 👤 Samuel L. Sachs
- 👤 Freeman K. Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:02
CPC Classifications
F; F28; F28G; F28G7/00; B; B08; B08B; B08B3/00; B08B3/04; B08B3/10; B08B3/12; Y; Y10; Y10S; Y10S134/00; Y10S134/902
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
149 words
An apparatus for effecting useful heat exchange in a liquid environment and a device for cleaning said apparatus in said liquid environment without removal therefrom comprising in combination: heat exchange means comprising a plurality of substantially parallel spaced apart banks of pipes each having external surfaces exposed to said liquid environment wherein said surfaces are subject to having substances accumulate thereon as a result of said liquid being in contact therewith, said substances affecting adversely the transfer of heat through said surfaces; ultrasonic cleaning means for producing ultrasonic energy in sufficient quantities to produce cavitation of said liquid to dislodge said substances, said ultrasonic cleaning means comprising a plurality of transducers arranged in a portable array and powered by suitable power supply means; and means for positioning said ultrasonic cleaning means adjacent to said surfaces between said banks of pipes without removal of said surfaces from said liquid environment.
Claim 2
Independent Claim
149 words
An apparatus for effecting useful heat exchange in a liquid environment and a device for cleaning said apparatus in said liquid environment without removal therefrom comprising in combination: heat exchange means comprising a plurality of substantially parallel spaced apart banks of pipes each having external surfaces exposed to said liquid environment wherein said surfaces are subject to having substances accumulate thereon as a result of said liquid being in contact therewith, said substances affecting adversely the transfer of heat through said surfaces; ultrasonic cleaning means for producing ultrasonic energy in sufficient quantities to produce cavitation of said liquid to dislodge said substances, said ultrasonic cleaning means comprising a plurality of transducers arranged in a portable array and powered by suitable power supply means; and means for positioning said ultrasonic cleaning means adjacent to said surfaces between said banks of pipes without removal of said surfaces from said liquid environment.
Claim 3
Dependent Claim
18 words
A combination in accordance with claim 1, further comprising means for sensing biofouling on said heat exchange apparatus.
Claim 4
Dependent Claim
27 words
A combination in accordance with claim 1, wherein said positioning means comprises means for moving and indexing said ultrasonic cleaning means relative to said heat exchange means.
Claim 5
Dependent Claim
23 words
A combination in accordance with claim 1, further comprising means for determining when said substances have been removed from said heat exchange means.
Claim 6
Dependent Claim
23 words
A combination in accordance with claim 1, wherein said ultrasonic cleaning means operates in substantially the range of 18 Khz to 80 Khz.
Claim 7
Dependent Claim
20 words
A combination in accordance with claim 1, wherein said ultrasonic cleaning means effects cavitation-type cleaning of said heat exchange means.
Claim 8
Dependent Claim
28 words
A combination in accordance with claim 6, wherein said cavitation-type cleaning, at one atmosphere of pressure, is accomplished at power levels between 0.5 to 2 watts/cm 2 .
Claim 9
Dependent Claim
22 words
A combination in accordance with claim 1, further comprising means for removing said substances from the proximity of said heat exchange means.
Claim 10
Dependent Claim
33 words
A combination in accordance with claim 8, wherein said removing means comprises means for providing a flow of said liquid over said surfaces of said heat exchange means for flushing said substances therefrom.
Claim 11
Dependent Claim
21 words
A combination in accordance with claim 1, further comprising means for monitoring the acoustical intensity radiated by said ultrasonic cleaning means.
Claim 12
Dependent Claim
19 words
A combination in accordance with claim 1, further comprising means for monitoring the temperature of said ultrasonic cleaning means.
Claim 13
Dependent Claim
31 words
A combination in accordance with claim 1, wherein said array is substantially planar and is dimensioned so as to permit its passage between said spaced apart substantially parallel banks of pipe.
Claim 14
Dependent Claim
44 words
A combination in accordance with claim 12, wherein said transducers are disposed substantially in line and are disposed to produce bi-directional acoustic radiation from said portable substantially planar array to accomplish simultaneous cleaning of adjacent pipe banks when said cleaning means is disposed therebetween.
Claim 15
Dependent Claim
17 words
A combination in accordance with claim 12, wherein said liquid is seawater and said substance is biofouling.
Claim 16
Dependent Claim
99 words
An ultrasonic cleaning apparatus for immersion in a liquid environment in which an object to be cleaned resides comprising: a housing forming a chamber therein; a plate fixedly secured within said housing, said plate having a plurality of apertures disposed therethrough; a plurality of ultrasonic transducers disposed within said apertures; means for mounting said transducers within said apertures; means for covering selected ends of said apertures, said covering means for reflecting acoustic radiation from said tranducers; and fluid means for filling said chamber of said housing, said fluid means for propagating acoustical waves from said transducers through said housing.
Claim 17
Dependent Claim
99 words
An ultrasonic cleaning apparatus for immersion in a liquid environment in which an object to be cleaned resides comprising: a housing forming a chamber therein; a plate fixedly secured within said housing, said plate having a plurality of apertures disposed therethrough; a plurality of ultrasonic transducers disposed within said apertures; means for mounting said transducers within said apertures; means for covering selected ends of said apertures, said covering means for reflecting acoustic radiation from said tranducers; and fluid means for filling said chamber of said housing, said fluid means for propagating acoustical waves from said transducers through said housing.
Claim 18
Dependent Claim
22 words
An apparatus in accordance with claim 15, wherein said apertures are arranged in said plate in a plurality of rows and columns.
Claim 19
Dependent Claim
37 words
An apparatus in accordance with claim 16, wherein alternate said apertures in said rows and columns are covered by said covering means on opposite sides of said plate so as to permit bi-directional radiation from said apparatus.
Claim 20
Dependent Claim
15 words
An apparatus in accordance with claim 15, wherein said covering means comprises a solid plate.
Claim 21
Dependent Claim
66 words
An apparatus in accordance with claim 15, wherein said mounting means comprises a plurality of support posts, one end of each post fixedly secured to an associated said transducer, said posts arranged radially about each of said transducers, the other ends of said posts fixedly secured to said plate adjacent to the perimeter of one of said apertures which is associated with one of said transducers.
Claim 22
Dependent Claim
17 words
An apparatus in accordance with claim 19, wherein said support posts are constructed of a vibration-dampening material.
Claim 23
Dependent Claim
15 words
An apparatus in accordance with claim 15, wherein said fluid means comprises a viscous liquid.
Claim 24
Dependent Claim
21 words
An apparatus in accordance with claim 15, further comprising means for positioning said plate proximate to said object to be cleaned.
Claim 25
Dependent Claim
23 words
An apparatus in accordance with claim 22, wherein said positioning means comprises means for moving and indexing said housing relative to said object.
Claim 26
Dependent Claim
24 words
An apparatus in accordance with claim 15, further comprising means for monitoring the acoustical intensity of said ultrasonic transducer as radiated from said housing.
Claim 27
Dependent Claim
17 words
An apparatus in accordance with claim 15, further comprising means for measuring the temperature within said housing.
Claim 28
Dependent Claim
33 words
An apparatus in accordance with claim 15, wherein said transducers are operable at sufficient power levels to cause cavitation in said liquid environment and therefore cavitation-type cleaning of said object to be cleaned.
Claim 29
Dependent Claim
28 words
An apparatus in accordance with claim 26, wherein said cavitation-type cleaning, at one atmosphere of pressure, is accomplished at power level between 0.5 to 2 watts/cm 2 .
Claim 30
Dependent Claim
22 words
An apparatus in accordance with claim 15, wherein said transducers operate substantially within the frequency range of 18 Khz to 80 Khz.
Claim 31
Dependent Claim
16 words
An apparatus in accordance with claim 15, wherein said transducers are of the piezo-electric ceramic type.
Claim 32
Dependent Claim
33 words
An apparatus in accordance with claim 15, wherein said apertures and therefore said transducers are spaced apart a distance substantially equal to one half wavelength multiples of the operating frequency of said transducers.
Claim 33
Dependent Claim
16 words
An apparatus in accordance with claim 15, wherein said housing is constructed of a semi-resilient material.
Claim 34
Independent Claim
116 words
A method for cleaning heat exchanger apparatuses functionally incorporating a plurality of spaced apart pipes having the external surfaces thereof in contact with a liquid which causes buildup of substances on said surfaces and reduces the heat transfer through said surfaces comprising the steps of: positioning ultrasonic transducer means dimensioned for insertion between said spaced apart pipes within said liquid between said spaced apart pipes proximate to a surface of said pipes to be cleaned so that the energy radiated from said transducer is directed toward said surface; applying power to said ultrasonic transducer means; and moving said ultrasonic transducer means relative to said surface of said heat exchanger at a rate permitting the cleaning thereof.
Claim 35
Independent Claim
116 words
A method for cleaning heat exchanger apparatuses functionally incorporating a plurality of spaced apart pipes having the external surfaces thereof in contact with a liquid which causes buildup of substances on said surfaces and reduces the heat transfer through said surfaces comprising the steps of: positioning ultrasonic transducer means dimensioned for insertion between said spaced apart pipes within said liquid between said spaced apart pipes proximate to a surface of said pipes to be cleaned so that the energy radiated from said transducer is directed toward said surface; applying power to said ultrasonic transducer means; and moving said ultrasonic transducer means relative to said surface of said heat exchanger at a rate permitting the cleaning thereof.
Claim 36
Dependent Claim
59 words
A method in accordance with claim 32, further comprising the steps of: defining the surface to be cleaned in contact with said liquid prior to said positioning step; monitoring the cleaning action of said at least one ultrasonic transducer subsequent to said applying of power step; and controlling said rate responsive to the information obtained by said monitoring step.
Claim 37
Dependent Claim
20 words
A method in accordance with claim 33, wherein said surface is defined and monitored by measuring the thermal transfer therethrough.
Claim 38
Dependent Claim
30 words
A method in accordance with claim 32, wherein said ultrasonic transducer is operated at power level sufficient to cause cavitation within said liquid and therefore cavitation-type cleaning of said surface.
Claim 39
Dependent Claim
22 words
A method in accordance with claim 32, further comprising the step of monitoring the power output of said at least one transducer.
Claim 40
Dependent Claim
33 words
A method in accordance with claim 32, wherein said plurality of spaced apart pipes are arranged in substantially parallel banks, said ultrasonic transducer means being dimensioned for insertion between said spaced apart banks.
Claim 41
Dependent Claim
41 words
A method in accordance with claim 37, wherein said ultrasonic transducer means comprises a substantially planar array of transducers arranged to radiate the bi-directionally from said array for simultaneous cleaning of said surfaces of adjacent banks of said spaced apart pipes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |