EP0189386A2 - Apparatus for generating in particular low-frequency sound - Google Patents
Apparatus for generating in particular low-frequency sound Download PDFInfo
- Publication number
- EP0189386A2 EP0189386A2 EP86850007A EP86850007A EP0189386A2 EP 0189386 A2 EP0189386 A2 EP 0189386A2 EP 86850007 A EP86850007 A EP 86850007A EP 86850007 A EP86850007 A EP 86850007A EP 0189386 A2 EP0189386 A2 EP 0189386A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- aperture
- space
- frequency
- chamber
- drive unit
- 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.)
- Granted
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/20—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of a vibrating fluid
Definitions
- the present invention relates to an apparatus for generating in particular low-frequency sound, comprising a drive unit which is adapted to generate sound by the supply of compressed air, and an open resonator which is connected to said drive unit and preferably is in the form of a straight pipe.
- the low--frequency generators normally are of the pneumatic type, the frequency generation being integrated with the oscillator (the diaphragm) and the frequency control being integrated with the horn.
- the sound transmitter is self-adjusting and operates on the system's own resonance frequency, and the frequency cannot be changed.
- Existing pneumatic sound transmitters with controlled frequency are highly sophisticated.
- the air supply valve conforms slavishly to changes of optional signals. The control is, so to speak, an "analog" control. Coupling in parallel of such known devices may result in phase shifts reducing the efficiency. It may also happen that entire systems or at least parts thereof are subjected to heavy resonant vibration.
- the drive unit comprises a housing having a chamber with an aperture opening in the resonator, a member oscillating within said chamber and having a first actuating surface which is located within a first space of said chamber and by means of which said member is movable, by supply of compressed air to said first space, in a direction away from said aperture, such that said aperture is opened, and a second actuating surface which is located in a second space and by means of which said body is movable, by supply of compressed air to said second space, in a direction toward said aperture, such that said aperture is closed, that said second actuating surface has a larger area than said first surface, and that said second space communicates with the atmosphere via a passage which is opened and closed by means of an electrically operated valve.
- Fig. 1 is a lateral view, partly in section, of an apparatus designed in accordance with the invention and adapted to generate low-frequency sound
- Fig. 2 illustrates an modified embodiment of such an apparatus
- Fig. 3 illustrates how a number of apparatuses according to the invention can be coupled in parallel for cleaning the combustion space of a furnace.
- the apparatus according to the invention as illustrated in Fig. 1 comprises a drive unit generally designated 1 0 and having means for generating low-frequency sound.
- a resonator 11 Connected to said drive unit 10 is a resonator 11 which may have any shape suitable in the context, for example flaring exponentially, although it preferably is in the form of a straight pipe.
- the drive unit 10 has a chamber 12 which is connected to the resonator 11 via a duct or aperture 13.
- the chamber 12 houses an approximately cylindrical member 14 provided at one end with a sealing means 15 which, in Fig. [, as its slightly raised peripheral edge engaging a portion around the aperture 13. Nearest the sealing means 15, the member 14 has a smaller cross-sectional area than the chamber 12, such that a first space 16 is formed. At some distance from the aperture 13, the member 14 widens to the cross-sectional area on the chamber by means of an inclined annular portion 35 forming an actuating surface.
- the cylindrical member terminates at a distance from the rear end of the chamber 12 to form a second space 17, and it appears that the side of the member 14 facing the space 17 has a much larger area than the transitional portion 35.
- the member 14 is provided in its rear side with a bore housing a spring 19 which strives to urge the member 14 toward the aperture 13.
- a duct 18 Extending between said first space 16 and said second space 17 is a duct 18 having a relatively small cross-sectional area and opening in the bore of the member 14.
- two passages 20, 22 are provided, the first of which extends from the space 17 and opens in a cavity in a valve 21 mounted on said drive unit 10. This cavity of the valve 21 communicates with the atmosphere through the second passage 22.
- the valve 21 is a solenoid valve having a coil 23 which is connected to a current source by means of wires 24 and within which.
- an armature 26 is movable back and forth in conventional manner in response to the activation of the coil 23.
- the armature 26 is connected with a valve member 25 which, in its advanced position, closes the entrance to the passage 22 communicating with the atmosphere. It will be seen that, by displacing the valve member 25, the communication between the space 17 and the atmosphere is opened and closed.
- the valve 21 is but schematically shown and may be replaced by other valves; the important thing is that the communication between the space 17 and the atmosphere can be opened and closed electrically at the desired frequency.
- a transverse bore provided in the drive unit 10 and opening in the space 16 houses a connection 27 for connecting a compressed air line 29 to said drive unit 10.
- Sound is generated by the apparatus according to Fig. 1 by supplying compressed air to the drive unit 10 via the line 29 and the connection 27.
- the compressed air first enters the space 16 and then goes to the space 17 via the duct 18 and the bore. Since the compressed air acts on a much larger area of the rear side of the member 14 than on the front side of said member, and since this force furthermore is supported by the force of the spring 19, the member 14 will be held with the seal 15 i engagement around the aperture 13, as shown in Fig. 1. If an electric voltage is applied to the coil 23 which thus moves the armature 26 away from the drive unit 10, the valve member 25 is lifted from its seat surface, thereby exposing the opening of the passage 22 in the valve cavity so that the space 17 will communicate with the atmosphere via the passages 20, 22.
- the pressure in the space 17 is reduced, and by the action of the compressed air on the actuating surface 35 the member 14 is moved to the right in Fig. 1, whereby the aperture 13 is opened toward the chamber 12.
- the valve member 25 again closes the passage 22, the pressure in the space 17 is again built up so that the member 14 is moved to the left in Fig. 1 and the aperture 13 is closed.
- This movement of the member 14 in the drive unit 10 generates the low-frequency sound which is amplified by the resonator 11.
- the reciprocating movement of the member 14 is controlled by means of the valve member 25 whose movement is dependent upon the movement of the armature 26 and, thus, by the activation of the coil 23.
- the movement of the member 14 and thus the frequency of the sound generated may be readily controlled electrically by connecting the lines 24 of the coil 23 to a suitable current source which is capable of supplying pulses of a frequency readily adjustable, preferably a square wave voltage.
- Fig. 2 illustrates a modified embodiment of the drive unit, a diaphragm 1 4 forming the reciprocable member.
- an annular ridge 28 is provided around the aperture 13 to the resonator 11, and this ridge is engaged by one side of the diaphragm 14 in the state corresponding to the one shown in Fig. 1.
- the space 16 is formed by the annular space between the ridge 28 and the periphery of the diaphragm 14, and the space 16 communicates with the space 14 on the rear side of the diaphragm 14 via the duct 18 which here is formed in the diaphragm proper.
- the diaphragm 14 is mounted such that it engages the ridge without actuation by compressed air, and when compressed air is supplied via the passage 29 and the connection 27, the air will flow, as in the embodiment previously described, into the space 16 and from there via the duct 18 into the space 17 which is vented in the same manner as in the earlier embodiment, the diaphragm 1 4 being urged away from the ridge 28 by the compressed air in the space 16.
- the resonator preferably is a straight pipe 11 because this will give a resonance curve having a relatively wide peak.
- lf on the other hand, the hom flares exponentially or in accordance with a Bessel curve, the degree of efficiency will be affected, and the resonance curve will be far more narrow.
- the resonance frequency is determined by the length of the horn. With low frequencies, the horns must be of considerable lengths and therefore may be curved, for example helically. For optimation of the horns at low frequencies, the horns may also comprise several different sections, such as straight pipes with conical sections.
- FIG. 3 illustrates an arrangement in which a combustion chamber 30 in a boiler is cleaned by means of several apparatuses according to the invention coupled in parallel and provided with a resonator 11 in the form of a long straight pipe projecting into the space 30 with its end facing away from the drive unit 10.
- the drive units 10 of the apparatuses are connected to a compressed air line 29 and to a control wire 24 which is connected to a current source 31.
- the current source 31 produces a square wave. voltage of readily controlled frequency, as indicated at 32. It is also possible to provide on a resonator 11 a sensor 34 which senses the resonance frequency of the resonator and is connected, via a wire 33, to the current source 31 for automatic control of the frequency of the square wave voltage.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
- Exhaust Silencers (AREA)
- Electrophonic Musical Instruments (AREA)
Abstract
Description
- The present invention relates to an apparatus for generating in particular low-frequency sound, comprising a drive unit which is adapted to generate sound by the supply of compressed air, and an open resonator which is connected to said drive unit and preferably is in the form of a straight pipe.
- It is known to remove soot from furnaces and to clean for example filters by means of low-frequency sound generated by means of low-frequency generators provided with resonators. For efficient soot removal and cleaning, considerable sound pressures are required, and this in turn means that large and cumbersome units must be used. Frequently, several such units must be used together. The low--frequency generators normally are of the pneumatic type, the frequency generation being integrated with the oscillator (the diaphragm) and the frequency control being integrated with the horn. The sound transmitter is self-adjusting and operates on the system's own resonance frequency, and the frequency cannot be changed. Existing pneumatic sound transmitters with controlled frequency are highly sophisticated. The air supply valve conforms slavishly to changes of optional signals. The control is, so to speak, an "analog" control. Coupling in parallel of such known devices may result in phase shifts reducing the efficiency. It may also happen that entire systems or at least parts thereof are subjected to heavy resonant vibration.
- It is the object of the present invention to eliminate the above mentioned disadvantages of prior art technique and to provide an extremely simple apparatus for generating low-frequency sound, said apparatus being provided with means for controlling the frequency of the sound generated. In this manner, it is possible without difficulty to couple in parallel a desired number of apparatuses of relatively small size. This object is achieved in that the drive unit comprises a housing having a chamber with an aperture opening in the resonator, a member oscillating within said chamber and having a first actuating surface which is located within a first space of said chamber and by means of which said member is movable, by supply of compressed air to said first space, in a direction away from said aperture, such that said aperture is opened, and a second actuating surface which is located in a second space and by means of which said body is movable, by supply of compressed air to said second space, in a direction toward said aperture, such that said aperture is closed, that said second actuating surface has a larger area than said first surface, and that said second space communicates with the atmosphere via a passage which is opened and closed by means of an electrically operated valve.
- The invention will be described in more detail below, reference being had to the accompanying drawings illustrating embodiments. Fig. 1 is a lateral view, partly in section, of an apparatus designed in accordance with the invention and adapted to generate low-frequency sound, and Fig. 2 illustrates an modified embodiment of such an apparatus. Fig. 3 illustrates how a number of apparatuses according to the invention can be coupled in parallel for cleaning the combustion space of a furnace. The apparatus according to the invention as illustrated in Fig. 1 comprises a drive unit generally designated 10 and having means for generating low-frequency sound. Connected to said drive unit 10 is a
resonator 11 which may have any shape suitable in the context, for example flaring exponentially, although it preferably is in the form of a straight pipe. The drive unit 10 has a chamber 12 which is connected to theresonator 11 via a duct oraperture 13. The chamber 12 houses an approximatelycylindrical member 14 provided at one end with a sealing means 15 which, in Fig. [, as its slightly raised peripheral edge engaging a portion around theaperture 13. Nearest the sealing means 15, themember 14 has a smaller cross-sectional area than the chamber 12, such that afirst space 16 is formed. At some distance from theaperture 13, themember 14 widens to the cross-sectional area on the chamber by means of an inclinedannular portion 35 forming an actuating surface. The cylindrical member terminates at a distance from the rear end of the chamber 12 to form asecond space 17, and it appears that the side of themember 14 facing thespace 17 has a much larger area than thetransitional portion 35. Themember 14 is provided in its rear side with a bore housing aspring 19 which strives to urge themember 14 toward theaperture 13. Extending between saidfirst space 16 and saidsecond space 17 is aduct 18 having a relatively small cross-sectional area and opening in the bore of themember 14. In the rear side of the drive unit 10, which is constituted by a removable lid, twopassages 20, 22 are provided, the first of which extends from thespace 17 and opens in a cavity in avalve 21 mounted on said drive unit 10. This cavity of thevalve 21 communicates with the atmosphere through thesecond passage 22. Thevalve 21 is a solenoid valve having acoil 23 which is connected to a current source by means ofwires 24 and within which. anarmature 26 is movable back and forth in conventional manner in response to the activation of thecoil 23. Thearmature 26 is connected with avalve member 25 which, in its advanced position, closes the entrance to thepassage 22 communicating with the atmosphere. It will be seen that, by displacing thevalve member 25, the communication between thespace 17 and the atmosphere is opened and closed. It should be emphasised in this connection that thevalve 21 is but schematically shown and may be replaced by other valves; the important thing is that the communication between thespace 17 and the atmosphere can be opened and closed electrically at the desired frequency. A transverse bore provided in the drive unit 10 and opening in thespace 16 houses aconnection 27 for connecting acompressed air line 29 to said drive unit 10. - Sound is generated by the apparatus according to Fig. 1 by supplying compressed air to the drive unit 10 via the
line 29 and theconnection 27. The compressed air first enters thespace 16 and then goes to thespace 17 via theduct 18 and the bore. Since the compressed air acts on a much larger area of the rear side of themember 14 than on the front side of said member, and since this force furthermore is supported by the force of thespring 19, themember 14 will be held with the seal 15 i engagement around theaperture 13, as shown in Fig. 1. If an electric voltage is applied to thecoil 23 which thus moves thearmature 26 away from the drive unit 10, thevalve member 25 is lifted from its seat surface, thereby exposing the opening of thepassage 22 in the valve cavity so that thespace 17 will communicate with the atmosphere via thepassages 20, 22. As a result, the pressure in thespace 17 is reduced, and by the action of the compressed air on the actuatingsurface 35 themember 14 is moved to the right in Fig. 1, whereby theaperture 13 is opened toward the chamber 12. When thevalve member 25 again closes thepassage 22, the pressure in thespace 17 is again built up so that themember 14 is moved to the left in Fig. 1 and theaperture 13 is closed. This movement of themember 14 in the drive unit 10 generates the low-frequency sound which is amplified by theresonator 11. It will be appreciated that the reciprocating movement of themember 14 is controlled by means of thevalve member 25 whose movement is dependent upon the movement of thearmature 26 and, thus, by the activation of thecoil 23. The movement of themember 14 and thus the frequency of the sound generated may be readily controlled electrically by connecting thelines 24 of thecoil 23 to a suitable current source which is capable of supplying pulses of a frequency readily adjustable, preferably a square wave voltage. - Fig. 2 illustrates a modified embodiment of the drive unit, a diaphragm 14 forming the reciprocable member. As will be seen, an
annular ridge 28 is provided around theaperture 13 to theresonator 11, and this ridge is engaged by one side of thediaphragm 14 in the state corresponding to the one shown in Fig. 1. In this embodiment, thespace 16 is formed by the annular space between theridge 28 and the periphery of thediaphragm 14, and thespace 16 communicates with thespace 14 on the rear side of thediaphragm 14 via theduct 18 which here is formed in the diaphragm proper. Thediaphragm 14 is mounted such that it engages the ridge without actuation by compressed air, and when compressed air is supplied via thepassage 29 and theconnection 27, the air will flow, as in the embodiment previously described, into thespace 16 and from there via theduct 18 into thespace 17 which is vented in the same manner as in the earlier embodiment, the diaphragm 14 being urged away from theridge 28 by the compressed air in thespace 16. - As has been indicated above, the resonator preferably is a
straight pipe 11 because this will give a resonance curve having a relatively wide peak. lf, on the other hand, the hom flares exponentially or in accordance with a Bessel curve, the degree of efficiency will be affected, and the resonance curve will be far more narrow. The resonance frequency is determined by the length of the horn. With low frequencies, the horns must be of considerable lengths and therefore may be curved, for example helically. For optimation of the horns at low frequencies, the horns may also comprise several different sections, such as straight pipes with conical sections. - Since the apparatus according to the invention can be controlled with the greatest ease, a plurality of apparatuses may be readily coupled in parallel without causing phase difficulties. If a plurality of apparatuses are coupled in synchronism (in phase), a considerable sound amplification may be achieved. Fig. 3 illustrates an arrangement in which a
combustion chamber 30 in a boiler is cleaned by means of several apparatuses according to the invention coupled in parallel and provided with a resonator 11 in the form of a long straight pipe projecting into thespace 30 with its end facing away from the drive unit 10. The drive units 10 of the apparatuses are connected to acompressed air line 29 and to acontrol wire 24 which is connected to acurrent source 31. Thecurrent source 31 produces a square wave. voltage of readily controlled frequency, as indicated at 32. It is also possible to provide on a resonator 11 asensor 34 which senses the resonance frequency of the resonator and is connected, via a wire 33, to thecurrent source 31 for automatic control of the frequency of the square wave voltage. - With the arrangement according to Fig. 3, all drive units 10 are supplied with a control voltage of the same frequency and the same phase. For optimation purposes, this control voltage is manually adjustable by means of a knob on the
current source 31. It is, of course, also conceivable to supply each driving unit with current from a current source of its own and separately to adjust the oscillation frequency of each drive unit
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT86850007T ATE56640T1 (en) | 1985-01-16 | 1986-01-15 | DEVICE FOR GENERATING PARTICULARLY LOW FREQUENCY SOUND VIBRATIONS. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8500188A SE451115B (en) | 1985-01-16 | 1985-01-16 | INSTALLATION FOR SOOTHING OF BOILERS OR SIMILAR, INCLUDING A MULTIPLE LOW-FREQUENT SOUND ALREADY DEVICES |
SE8500188 | 1985-01-16 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0189386A2 true EP0189386A2 (en) | 1986-07-30 |
EP0189386A3 EP0189386A3 (en) | 1987-11-19 |
EP0189386B1 EP0189386B1 (en) | 1990-09-19 |
Family
ID=20358780
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP86850007A Expired - Lifetime EP0189386B1 (en) | 1985-01-16 | 1986-01-15 | Apparatus for generating in particular low-frequency sound |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0189386B1 (en) |
AT (1) | ATE56640T1 (en) |
DE (1) | DE3674219D1 (en) |
SE (1) | SE451115B (en) |
WO (1) | WO1987004953A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0692500A1 (en) | 1994-07-14 | 1996-01-17 | Union Carbide Chemicals & Plastics Technology Corporation | Improved gas phase fluidized bed olefin polymerization process using sound waves |
FR2757784A1 (en) * | 1996-12-27 | 1998-07-03 | Bp Chemicals Snc | PROCESSING METHOD USING VIBRATION OF THE WALL OF A FLUIDIZED BED REACTOR FOR GAS PHASE POLYMERIZATION |
US9443505B2 (en) | 2013-08-16 | 2016-09-13 | Kevin Allan Dooley, Inc. | Systems and methods for control of infrasound pressures |
US10048151B2 (en) | 2013-08-16 | 2018-08-14 | Kevin Allan Dooley, Inc. | Systems and methods for control of motion sickness within a moving structure due to infrasound pressures |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3022039A (en) * | 1958-12-22 | 1962-02-20 | Gates Rubber Co | Diaphragm for valve |
EP0006833A2 (en) * | 1978-07-03 | 1980-01-09 | Mats Olsson Konsult Ab | Low-frequency sound generator |
WO1980002887A1 (en) * | 1979-06-11 | 1980-12-24 | Kockumation Ab | An improvement in gas-operated pressure oscillation generators of the diaphragm valve type |
WO1981000064A1 (en) * | 1979-07-03 | 1981-01-22 | Kockumation Ab | Pneumatic diaphragm valve pulsator |
EP0045292A2 (en) * | 1980-07-25 | 1982-02-03 | Kockumation Ab | Fluid operated pressure oscillation generator |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB191109364A (en) * | 1910-04-18 | 1912-01-11 | Etablissements Gaumont | An Improved Fluid Pressure Relay for Amplifying Sounds. |
FR774990A (en) * | 1934-05-04 | 1934-12-17 | Buzzer | |
US3053031A (en) * | 1959-10-19 | 1962-09-11 | Pangborn Corp | Sonic cleaning of dust filters |
DE1407922B2 (en) * | 1963-11-18 | 1973-08-16 | Gebruder Buhler AG, Uzwil (Schweiz) | FILTER SYSTEM FOR DUST SEPARATION FROM AIR |
FR1443257A (en) * | 1965-05-07 | 1966-06-24 | Improvements to valves | |
US3917233A (en) * | 1973-08-24 | 1975-11-04 | Sherwin Williams Co | Vibrator |
SE391458B (en) * | 1974-05-02 | 1977-02-21 | Svenska Flaektfabriken Ab | KIT AND DEVICE FOR CLEANING HOSE FILTER WITH PRESSURE PULSE OF CLEANING MEDIUM |
US4120699A (en) * | 1974-11-07 | 1978-10-17 | Alvin B. Kennedy, Jr. | Method for acoustical cleaning |
CH592466A5 (en) * | 1975-05-05 | 1977-10-31 | Buehler Ag Geb | |
CH625969A5 (en) * | 1977-07-15 | 1981-10-30 | Buehler Ag Geb | |
SE7805006L (en) * | 1978-05-02 | 1979-11-03 | Kockums Automation | AT SONIC CLEANING |
DE3025548A1 (en) * | 1980-07-05 | 1982-01-21 | Degussa Ag, 6000 Frankfurt | METHOD FOR CLEANING FILTER CLOTHES BY MEANS OF PRESSURE GAS IMPULS FOR SOLID DETECTION FROM GASES |
SE425597B (en) * | 1980-10-13 | 1982-10-18 | Ekstroms Vermetekniska Ab | FORCED CONTROL SOUND STRUCTORS FOR THE INFRALUE AREA |
-
1985
- 1985-01-16 SE SE8500188A patent/SE451115B/en not_active IP Right Cessation
-
1986
- 1986-01-15 EP EP86850007A patent/EP0189386B1/en not_active Expired - Lifetime
- 1986-01-15 AT AT86850007T patent/ATE56640T1/en not_active IP Right Cessation
- 1986-01-15 DE DE8686850007T patent/DE3674219D1/en not_active Expired - Fee Related
- 1986-02-14 WO PCT/SE1986/000060 patent/WO1987004953A1/en unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3022039A (en) * | 1958-12-22 | 1962-02-20 | Gates Rubber Co | Diaphragm for valve |
EP0006833A2 (en) * | 1978-07-03 | 1980-01-09 | Mats Olsson Konsult Ab | Low-frequency sound generator |
WO1980002887A1 (en) * | 1979-06-11 | 1980-12-24 | Kockumation Ab | An improvement in gas-operated pressure oscillation generators of the diaphragm valve type |
WO1981000064A1 (en) * | 1979-07-03 | 1981-01-22 | Kockumation Ab | Pneumatic diaphragm valve pulsator |
EP0045292A2 (en) * | 1980-07-25 | 1982-02-03 | Kockumation Ab | Fluid operated pressure oscillation generator |
Non-Patent Citations (1)
Title |
---|
AUFBEREITUNGS-TECHNIK, vol. 17, no. 12, 1976, pages 636-637, DE; O. ALBRECHT: "Sch}ttgut-R}ttelung mittels pneumatischer Druckwellen" * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0692500A1 (en) | 1994-07-14 | 1996-01-17 | Union Carbide Chemicals & Plastics Technology Corporation | Improved gas phase fluidized bed olefin polymerization process using sound waves |
FR2757784A1 (en) * | 1996-12-27 | 1998-07-03 | Bp Chemicals Snc | PROCESSING METHOD USING VIBRATION OF THE WALL OF A FLUIDIZED BED REACTOR FOR GAS PHASE POLYMERIZATION |
WO1998029186A1 (en) * | 1996-12-27 | 1998-07-09 | Bp Chemicals Limited | Process for treating the wall of a reactor by vibrations |
US9443505B2 (en) | 2013-08-16 | 2016-09-13 | Kevin Allan Dooley, Inc. | Systems and methods for control of infrasound pressures |
US10048151B2 (en) | 2013-08-16 | 2018-08-14 | Kevin Allan Dooley, Inc. | Systems and methods for control of motion sickness within a moving structure due to infrasound pressures |
Also Published As
Publication number | Publication date |
---|---|
SE8500188D0 (en) | 1985-01-16 |
EP0189386B1 (en) | 1990-09-19 |
EP0189386A3 (en) | 1987-11-19 |
SE451115B (en) | 1987-09-07 |
SE8500188L (en) | 1986-07-17 |
DE3674219D1 (en) | 1990-10-25 |
ATE56640T1 (en) | 1990-10-15 |
WO1987004953A1 (en) | 1987-08-27 |
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