Abstract: An apparatus for cleaning a detector comprising a housing and a bowl connected to the housing having a detector chamber adapted for enclosing a detector to be cleaned, a contacting surface positioned on the bowl, and one of more air nozzles positioned within the detector chamber for directing one or more bursts of compressed air at a detector to clean the detector, and a fan positioned within the housing operable to draw air within the detector chamber into a filter, and a dust collector for containing dirt and debris dislodged from a detector during the cleaning operation.

Abstract: A cleaning device (1) for cleaning a carpet (70) having face yarns (74) that extend over a distance of several millimeters from a generally planar backing (72) to define a carpet surface (76), comprising: an oscillator unit (30), including: an oscillator (32); an oscillation space (34) defined by or accommodating at least part of the oscillator, and accessible through a jet opening (36) via which ambient fluid is alternatingly drawn into the oscillation space and expelled from the oscillation space during operation of the oscillator; a nozzle (10), including a carpet surface penetrator (14) that defines said jet opening; a support structure (12) configured to support the nozzle against the carpet, such that, in a supported condition of the nozzle against the carpet, the penetrator penetrates the carpet surface and the jet opening is disposed at least partially below the carpet surface.

Abstract: A vacuum cleaning device comprises a unit (1) in which an oscillating airflow is generated which substantially zero net flow and an asymmetry between the suction and the blowing phases, such that in the blowing phase a jet is generated. A generator (31) which is needed for generating the oscillating airflow comprises a movable surface (30) which is integrated in a wall (12) of a housing (10) having an internal space (11) and at least one opening (13) for allowing air to flow to and from the internal space (11). The jet can be generates when the so-called Strouhal number, being the frequency of the movement of the movable surface (30) multiplied by a characteristic dimension of the opening (13) and divided by the velocity of the air in the opening (13), is not higher than a predetermined maximum.

Abstract: A vacuum cleaning device comprises a unit (1) for aerodynamically affecting dust particles and/or a surface to be cleaned. The unit (1) comprises a housing (30) having a housing wall (31) encompassing two internal sections (20, 22), and a movable surface (11) arranged at an interface of the two sections (20, 22), wherein a portion (32) of the housing wall (31) delimiting a first section (20) is provided with at least one opening (21), and wherein means for actuating the movable surface (11) are arranged in a second section (22). A portion (33) of the housing wall (31) delimiting the second section (22) is adapted to at least hinder exchange of air between an inside of this section (22) and an outside of the housing (30) at the location of this section (22), in order to at least hinder a migration of dust to the second section (22).

Abstract: A method of in situ scale removal from a heat exchange body suspended in a wet cooling tower. At least one air blast is generated by a generator implementing controlled expansion via a nozzle of a mass of compressed gas in a nozzle towards a zone of the body. The generator is opened at a distance from the zone, and the method repeats the operation after moving the generator under the body outside the zone.

Abstract: A filter cleaning system for cleaning a filter element is provided. The filter cleaning system includes a set of pulse nozzles and a compressed air supply, which rotate together during a cleaning cycle to release pulse blasts at predetermined time intervals to clean the filter element.

Abstract: A gas impulse blower for cleaning a surface within a vessel is fillable with a combustion gas-oxi-dizer mixture. The blower comprises: (a) a combustion assembly configured to generate a deflagration wave; and (b) an impulse generator having an inlet and an outlet and adapted to receive the deflagration wave into said inlet and eject the wave from said outlet onto a surface to be cleaned. The impulse generator has a compartmentalized housing comprising at least two serially-connected compartments. The compartments are configured for being fed with said gas-oxidizer mixture by the combustion assembly in an individual manner so as to conduct the wave to the outlet.

Abstract: A motorised pool-cleaning device (1) includes: a suction element (30); a rotary element (4) for moving the device, which define first (2) and second (3) bearing axles; a support (18) consisting of (i) a first central part (24) and (ii) first (25) and second (26) side covers which are connected to either side of the first central part, such as to form the chassis of the motorised device, and which support the rotary movement element (4); and a drive element (16, 17) for rotating the rotary movement element (4), which are disposed on the first and second side covers in a cantilevered manner.

Abstract: An apparatus for treating an exposed surface. The apparatus has an elongate support with a proximal region and a distal region. The proximal region is engagable by a user to controllably reposition the elongate support and thereby situate the distal region at an exposed surface to be treated. At least one elongate element is provided at the distal region of the elongate support. The at least one elongate element is moveable at the distal region to repeatedly contact an exposed surface at which the elongate element is situated to thereby separate matter from an exposed surface at which the elongate element is situated.

Abstract: A method of in situ scale removal from a heat exchange body suspended in a wet cooling tower, wherein the method generates at least one air blast by means of a generator implementing controlled expansion via a nozzle of a mass of compressed gas in a nozzle towards a zone of the body, the generator being opened at a distance (H) from said zone, and the method consisting in repeating said operation after moving the generator under the body outside said zone.

Abstract: The brushless vacuum cleaner is an electrical cleaning device that would feature conventional components from traditional upright vacuum cleaners but would use forced air to agitate debris from the surface to be cleaned. The brushless vacuum cleaner would consist of a base unit with multiple air injectors on the bottom, a pump case located on top of the base unit, a collection unit extending upward from the pump case, a vacuum chamber connecting the bottom of the base unit to the collection unit, and a handle that features various control buttons. The pump case would contain an electrical motor which would operate a dual-cycle agitator responsible for pulsing air flow through alternating air injectors on every other cycle. This system would replace the beater brush found on conventional upright vacuum cleaners, thus creating less wear and tear to carpeting and prolonging the life of the carpet.

Abstract: The present disclosure relates to a pulse cleaner for cleaning a diesel exhaust aftertreatment device. The pulse cleaner includes a cabinet, a diesel exhaust aftertreatment device mount positioned within the cabinet for mounting the diesel exhaust aftertreatment device during pulse cleaning, and a collection filter positioned within the cabinet for collecting material displaced from the diesel exhaust aftertreatment device during cleaning. The pulse cleaner can be equipped with features such as an exhaust aftertreatment device core temperature sensor, an air flow concentrator or an air swirling vane. The pulse cleaner can also include adapters for providing system compatibility with different styles of exhaust aftertreatment devices.

Abstract: An agitation apparatus which is suitable for use in a cleaning head of a vacuum cleaner includes first and second flow paths. Each of these flow paths has a resonant cavity and an inlet/outlet port which joins the cavity to a space within the cleaning head. A generator, such as a loudspeaker with a diaphragm, generates an alternating pressure wave between the ports. Pressure waves are emitted from one of the ports in an anti-phase relationship with the pressure waves from the other of the ports, thus reducing operating noise. Due to both sides of the generator or diaphragm being exposed to an equal static pressure, the generator operates more reliably. A plurality of these arrangements can be provided across the cleaning head, and a part of the agitation apparatus, such as the driver, can be mounted on the main body of the vacuum cleaner.

Abstract: A de-duster for a moving printing material web includes at least one blower nozzle assigned to a first side of the printing material web, and at least one blower nozzle assigned to a second side of the printing material web. The blower nozzles are set counter to web travel direction at an angle ?. The de-duster further includes at least one extraction nozzle assigned to the first side of the printing material web, and at least one extraction nozzle assigned to the second side of the printing material web. The extraction nozzles are set counter to the web travel direction at an acute angle ?. Each of the at least one blower nozzle is disposed between the at least one extraction nozzle at a respective side of the printing material web and the respective side of the printing material web. A combination of the de-duster and a cutting device, a folder with the combination, and a web-processing printing press in combination with the folder, are also provided.

Abstract: Toner xerographically adhered to a material, such as a sheet of paper, may be removed using a solvent-based or solventless approach. The application of ultrasonic tamping, scraping and brushing may aid in removing toner particles. In a solvent-based approach, a solvent may be applied generally or the solvent may be targeted specifically to the toner covered portions of the material to loosen the adhesive securement of the toner to the material. Thereafter, the toner is subjected to a mechanical abrasion using ultrasonic and physical agitation to cause flaking of the toner.

Abstract: An automatic pool cleaner of the type having an elongated body (11) with an inlet, a flexible seal (32) mounted on an end of the elongated body to bear against the surface of the wall or floor of the pool, a flip-flop valve (25) positioned adjacent the inlet (21) of the elongated body (11) and capable of moving back and forth between two extreme positions for controlling the flow of water through the elongated body and in so doing producing a “water hammer effect” which acts on the automatic pool cleaner to propel it across the surface and wherein the flip-flop valve includes a substantially wedge shaped hammer (25) formed by two spaced substantially triangular sides interconnected by a central body narrower than the sides and a continuous end surface (61) connecting respective ends of the substantially triangular side pieces such that the hammer has continuous sides and cavities between the sides due to the central body being narrower than the sides, the continuous end surface (61) having indenta

Abstract: Apparatus for dislodging an accretion of a substance from the vicinity of a vessel, includes apparatus for generating gas-borne shock waves in the vicinity of a vessel, thereby to expose a substance accrued on a surface thereof to separation forces causing at least partial separation of the substance from the surface, so as to facilitate removal of the at least partially separated substance therefrom; and support apparatus for supporting the apparatus for generating shock waves in a selected association relative to the vessel.

Abstract: Apparatus for use with automatic pool cleaners includes a tube which defines a flow channel for water drawn pump from the pool through a house by a remote pump. The tube includes tubular sections (10A, 10B) joined by a joint (11) which operates to move one tube section between first and second angularly displaced positions. Means are provided for periodically causing the movable tube section to move about the joint with sufficient force to impart movement to the hose to cause a change in direction of the cleaner.

Abstract: A failsafe valve assembly for use in clean-in-place systems that arranges multiple product blocking valves with one bleed valve. The failsafe valve assembly having a junction providing fluid communication between the primary isolation valve, the one bleed valve and the multiple product valves. The failsafe valve assembly further providing continuous flow cleaning capabilities.

Abstract: A method and system for cleaning a reticle. There is provided a clean chamber and a reticle having a pair of opposing edges and a pair of opposing surfaces which is to be cleaned disposed in the clean chamber. A gas inert to the reticle is directed in a direction tangential to each of the surfaces of the reticle and along one the edge of the reticle. The gas is exhausted from a location spaced from the other of the pair of opposing edges and remote form the one edge. An optional monitor monitors the particles in the exhausted gas. The gas is preferably applied in pulses which have a pulse length of from about 0.05 second to about 1 second and a pulse repetition rate of from about 0.5/second to about 40/second. The gas is preferably ionized and preferably is applied at a pressure of from about 20 psi to about 120 psi. The stepper chamber is vibrationally isolated from the blow-off chamber.

Abstract: Apparatus for dislodging an accretion of a substance from the vicinity of a vessel, includes apparatus for generating gas-borne shock waves in the vicinity of a vessel, thereby to expose a substance accrued on a surface thereof to separation forces causing at least partial separation of the substance from the surface, so as to facilitate removal of the at least partially separated substance therefrom; and support apparatus for supporting the apparatus for generating shock waves in a selected association relative to the vessel.

Abstract: The present invention relates to an electrostatic air blower which is preferably intended for use in cleaning optofibers without risking the contamination of said fibers with, e.g., metal particles that may have been loosened from electrodes used in a cleaning process. The ends of optofibers can be cleaned simply and reliably prior to welding said ends together, with the aid of said electrostatic air blower. The electrostatic air blower includes two ceramic plasma caoons (11, 12) which face towards one another at a given distance apart. Each plasma cannon includes a ceramic tube which houses an electrode. Repeated discharges between the electrodes in the tubes causes pressure waves to be generated in the air present between the tube orifices.

Abstract: A high pressure gas cleaning purge cleaning silicon oxide dust deposits from inside a dry vacuum pump while installed on a crystal grower. The high pressure gas cleaning purge is performed before or after each crystal is grown. The high pressure gas flow is injected into the inlet of the dry vacuum pump and repeatedly turned on and off to create differing turbulent flow patterns within the pump. The differing turbulent flow patterns effectively remove substantial quantities of the silicon oxide dust deposited in the pump during crystal growing.

Abstract: Suction nozzle for a vacuum cleaner including a suction nozzle body including; a main air flow passage having a main suction hole for drawing external air and a discharge hole for providing the drawn air to a body of the vacuum cleaner, and a supplementary air flow passage having a supplementary air flow passage for drawing external air and an opening for providing the external air drawn through the supplementary suction hole to the main air flow passage, and vibration generating means mounted in the supplementary air flow passage for generating a vibrating force by an air flow drawn through the supplementary suction hole, thereby facilitating an automatic removal of various foreign matters stuck to a surface of bedding, whereby improving a cleaning efficiency.

Abstract: The present invention discloses a portable cleaning system for ductwork and a method utilizing the cleaning system. The system includes a sound or air pulse generator for producing infrasound air pulses for short duration and introducing the air pulses into an air conduit which causes the air conduit to resonate or vibrate at a given infrasound frequency. The induced vibration causes contaminants in the ductwork to be entrained in the air pulses and carried with the air pulses to an exit of the air conduit where the air is filtered to remove the contaminants.

Abstract: A cleaning apparatus for cleaning a probe card having a contact element to be brought into electrical contact with a pad of a circuit to be inspected, comprises a conductive brush to be brought into contact at least with the contact element to clean the probe card, and a gas blow mechanism for intermittently blowing gas to the brush. The conductive brush is vibrated by the gas blow, and a particle adhered from the probe card is removed by the vibrating brush and the gas jet.

Abstract: A swimming pool cleaner has a body which defines a liquid inlet and an outlet which is connected via a hose to a source of suction. A throat between the inlet and the outlet defines a region of reduced cross-sectional area, causing a zone of low pressure as liquid flows through the throat. A valve element in the form of a cylindrical shuttle is located in a bore which intersects the throat, and which can move into the throat to block it intermittently. An auxiliary suction passage connects the rear of the bore to the outlet, so that suction is applied to both ends of the shuttle, causing it to reciprocate in the bore, periodically obstructing the flow of liquid through the throat. This causes the cleaner to move across the submerged surface. The design of the cleaner makes it resistant to jamming due to objects being trapped between the valve element and the throat.

Abstract: An automatic interior cleaning system for a powdered material processing device cleans interior surfaces of powdered material processing devices such as silos, mixers, and dust collectors. A compressor and an accumulator tank supply a cleaning gas, preferably air, at a sufficient pressure to dislodge residues of powdered materials that collect on interior surfaces of a powdered material processing device. A valve connecting the accumulator tank to a cleaning nozzle tube opens and closes, supplying a pulse of air to the cleaning nozzle tube. Slits in the cleaning nozzle tube deliver the pulse of pressurized air to an inside surface of the powdered material processing device. The pulse of pressurized air produces a shock wave which dislodges residues from the interior surface of the powdered material processing device. Automatic removal of residues during processing prevents contamination of subsequently processed materials.

Abstract: A swimming pool cleaner comprising an operating head providing two inlet openings and passages therethrough connecting to a single outlet is disclosed. The cleaner includes a valve to close intermittently in one passage and, optionally, a restriction valve in the other passage operable between greater and lesser degrees of restriction to enhance the smooth, consistent, and continual collection of dirt and debris from the pool surface.

Abstract: A material is transported by suction through a transporting line (1,2) connected with a suction source (4) and communicating with atmosphere through a passage (8), and the area and shape of the passage is periodically changed by a power-drive operated element (10,11) during the transporting.

Abstract: The present invention discloses a method and an apparatus for removing deposits from materials. By feeding unidirectional pulsating air pulsating while flowing in one direction, porous member (4), to materials (m) supplied from above the porous member (4) stretched laterally in a main body case (1A) of a removing apparatus main body (1), the deposits from the materials (m) are removed by the action of the unidirectional pulsating air. The apparatus comprises a removing apparatus main body (1) possessing a feed port (5) and a product outlet (11) disposed above a porous member (4) stretched laterally in a main body case (1A), and an air vibration generating device (30) for feeding unidirectional pulsating air pulsating while flowing in one direction, toward the porous member (4) from above the porous member (4).

Abstract: A disc for use with an automatic swimming pool cleaner which operates on a substantial intermittent reduction in water flow through the swimming pool cleaner is disclosed. The disc is made of flexible material and has grooves formed symmetrically across and into the under surface of the disc.

Abstract: A vacuum cleaner with an air vibration suction nozzle for application to a workpiece, whereby air vibrations produced by a transducer supported and sealed in the nozzle housing vibrate the workpiece, or debris with respect to the workpiece, and any loose particles on the workpiece are then drawn into the vacuum cleaner through the suction nozzle. The suction nozzle is provided with an elongated nozzle opening, a plurality of wheels to guide the nozzle over the workpiece, a stationary brush adjacent the nozzle opening, and a viewport and interior light for illuminating and viewing the workpiece through the nozzle opening. Controls for adjusting both the frequency and amplitude of the airwaves produced by the transducer are also provided.

Abstract: A bottom wall of an air discharging chamber in a cleaner head is formed with an air jetting slit. The air jetting slit is arranged in the substantially perpendicular direction to the advancing direction of a panellike body. A bottom wall of an air sucking chamber in the cleaner head is provided with an air sucking slit located in parallel with the air jetting slit. The air discharging chamber includes a supersonic generator therein. The supersonic generator is provided with a continuous groove in parallel with the air jetting slit. The air is turned into an air flow incorporating ultrasonic waves after being passed through the continuous groove, and is successively jetted from the air jetting slit.

Abstract: A pool sweep having a continuously-cycling, flow-interrupting valve at the upstream entrance to an inertial flow chamber. The valve has an entrance mouth with one or more closure lips pivoting been open and closed positions to open and close the mouth. The lips are biased towards closure with low creep biasing means, as by materials having a strain at its elastic limit of below 0.5 such as one or more metal springs urging the lip toward closure. The magnitude of the opening bias throughout the range of movement of the lips between open and close under dynamic flow conditions is substantially less than the closing force created by the water flow through the valve mouth urging the lips towards closure and substantially greater than the closing force imparted by flow through the mouth during lip travel from full closure to the open position.

Abstract: A high velocity air and stationary disturber cleaner for cleaning surfaces by drawing air under flexible film seals. A vacuum enclosed in a housing provides the suction force to draw the air under the seal, tangent to the surface to be cleaned, thus removing adhered particles. Disturbers are placed on the surface of the seals in contact with the surface to be cleaned to loosen particles to be removed. The brush density, the fiber length and a plastic film incorporated into the brush design are all ways to limit the amount of air flow through the bulk of the brushes for better cleaning efficiency.

Abstract: A high velocity air and stationary disturber cleaner for cleaning surfaces by drawing air under flexible film seals. A vacuum enclosed in a housing provides the suction force to draw the air under the seal, tangent to the surface to be cleaned, thus removing adhered particles. Disturbers are placed on the surface of the seals in contact with the surface to be cleaned to loosen particles to be removed. The brush density, the fiber length and a plastic film incorporated into the brush design are all ways to limit the amount of air flow through the bulk of the brushes for better cleaning efficiency.

Abstract: A pool cleaner (1) has a suction head (2) with a flow interrupter having a ball (12) movable to interrupt a primary liquid flow through the suction head and a release means (16) is located downstream of the ball (12) and has a flow passage allowing an auxiliary liquid flow into the tube when the ball interrupts the primary liquid flow. The auxiliary flow abruptly dislodges the ball and allows primary liquid flow.

Abstract: A high velocity air and stationary disturber cleaner for cleaning surfaces by drawing air under flexible film seals. A vacuum enclosed in a housing provides the suction force to draw the air under the seal, tangent to the surface to be cleaned, thus removing adhered particles. Disturbers are placed on the surface of the seals in contact with the surface to be cleaned to loosen particles to be removed. The brush density, the fiber length and a plastic film incorporated into the brush design are all ways to limit the amount of air flow through the bulk of the brushes for better cleaning efficiency.

Abstract: A suction transporting device for transporting a material has a suction unit, a transporting line connected with the suction unit and having an inlet for receiving a material to be transported and an outlet for discharging the material to be transported and a unit for modulating a suction force of a suction produced in the transporting line by the suction unit, the modulating unit including a passage adapted to communicate the interior of the transporting line with atmosphere, an adjusting element operative for adjusting an initial area and shape of a minimal cross-section of the passage, and a valve mechanism including a drive, a speed controller for controlling a speed of the drive, and a valve body connected with the drive and cooperating with the passage so that when the valve body is displaced by the drive, an initial area and shape of the minimal cross-section of the passage is periodically changed.

Abstract: An output of a electric driven blower in a cleaner main body is controlled in response to a detection value of a pressure sensor which detects an operation condition in the cleaner main body. A change-over level setting value is provided as a control value for the sensor so as to form a judgment point for changing over a control condition of the blower. A return level setting value is provided as a control value for the sensor so as to form a judgment point for returning to a previous control condition of the blower from a changed-over condition of the blower. When the detection value of the sensor is more than the change-over level setting value, the return level setting value is set higher than the change-over setting value, thereby the output of the blower is increased, or the return level setting value is set a lower than the change-over level setting value, thereby the output of the blower is decreased.

Abstract: A submersible automatic swimming pool cleaner (10) comprises a body (13) defining a flow passage (14) extending between an inlet (15) thereto and an outlet (16) therefrom. An auxiliary inlet (15) to the passage is also defined in body (13). A flap (19) is mounted in inlet (18) and is pivotal between a first position, wherein the auxiliary inlet (18) is open and wherein part of the flap extends into passage (14) to form a constriction to liquid flow through the passage, and a second position, wherein the auxiliary inlet (18) is closed and the constriction is removed. In use, the flap (19) oscillates between the first and second positions thereby causing water flow through the cleaner intermittently to be varied. In this way kinetic energy is imparted to the cleaner to cause it to move over a surface (12) to be cleaned, while sucking debris from the surface.

Abstract: A method for producing selectively controlled pressure pulses in a mass of gas, particularly contained in a space of large dimensions. To achieve a sufficiently high power in the pulses, the pulses are generated by a valveless displacement machine in which the pressure when the machine opens towards its outlet port differs from the pressure of the mass of gas. The pulse is generated as the working fluid, due to said pressure difference, flows at high velocity through the outlet port. An acoustic power of the generated pulses of up to 20 kW can be attained by the method. The invention also concerns a rotary displacement machine for performing the method.

Abstract: The invention relates to a cleaning device particularly a swimming pool cleaner for automatically cleaning submerged surfaces in which an induced flow through the cleaner is intermittently interrupted to cause random movement of the cleaner over the surface to be cleaned and in which a valve is freely movable towards and away from a valve seat in a flow passage through the cleaner. Preferably the closure member is spherical and has a specific gravity only slightly greater than that of the liquid in which the device is to be used.

Abstract: This invention relates to an automatic pool cleaner, particularly suitable for domestic swimming pools which operate on the interruption of an induced flow of water through the cleaner and wherein the control of the interruption is effected through a tubular axially resilient diaphragm one end of which is closed and adapted to hold normally closed a passage from the head of the pool cleaner to the usual form of flexible hose connecting the pool cleaner to the filtration unit.

Abstract: A system for removing extremely fine specks of contaminants from a surface by means of applying air-borne vibrations to the speck coincident with creation of a neutral static charge acting on the speck.

Abstract: A control system for controlling a cleaning apparatus used for cleaning a steam generator includes a valve manifold which is controlled by a control console to direct a pressurized fluid to either a jetting outlet or a flushing outlet of the cleaning apparatus associated with the steam generator. The control console also controls a motor controller which defines the incremental distance that the jetting outlet is moved within the steam generator to clean different portions of the steam generator. The motor controller is remotely controllable from a platform control device so that the position of the jetting outlet can be changed by a person located on or near the steam generator during initial alignment and limit switch positioning. The control console also controls an evacuation circuit which extracts the fluid pumped into the steam generator and the sludge or other substances loosened therefrom.

Abstract: A ribbon of flexible fabric (e.g., nylon) is folded and riveted near the fold to form an attachment loop. The loop is then coupled on a centrally located support rod inside an air duct, the ribbon ends extending beyond the exit of the duct. When air is forced through the duct, the free ends oscillate rapidly to brush away particulates on a surface being cleaned. The support rod is a portion of a clip which is removably coupled to the duct. The duct is cylindrical and may comprise a common, commercially available vacuum cleaner tube.

Abstract: A sonic cleaning device and method for removing accumulated fine particles from surfaces such as in heat exchangers using sonic energy vibrations. In the invention, a gas is passed through a tube having internally corrugated walls and having the tube outlet end attached to the inlet end of an expanding horn. The gas flows past the corrugations at high velocity and produces high intensity sonic vibrations within the tube, and the vibrations are amplified by passage through the horn. The horn outlet is directed at a surface to be cleaned and the accumulated particles are fluidized by the sonic energy and removed from the surface by the flowing gas and/or by gravity.

Abstract: Apparatus for removing dust from the flat surfaces of stationary or moving sheets, webs, plates or similar objects has a unit which converts a low-pressure laminar air stream into a pulsating air stream. The pulsating stream contacts the surface of an object simultaneously with ultrasonic radiation. The direction of flow of the pulsating air stream, which can be ionized, may be parallel with or at right angles to the direction of propagation of ultrasonic radiation.