Method and fluidic apparatus for generating pulsed and oscillating air flow for surface cleaning and sweeping

Patent metadata

Field	Value
Publication number	US-9765491-B2
Application number	US-201414244441-A
Country	US
Kind code	B2
Filing date	Apr 3, 2014
Priority date	Apr 3, 2013
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

An oscillating or pulsing fluid stream, or flow, is produced from a flow of pressurized air by fluidic apparatus in a device configured for use in surface cleaning, sweeping, lawn care applications, and the like. A converging nozzle assembly defining a tapered internal lumen having a smooth narrowing profile is configured to generate at a power nozzle a high velocity stream with minimal pressure drop. Downstream of the power nozzle, first and second control ports are in fluid communication with the high velocity stream and with each other via an inertance loop having a lumen of selected cross sectional area and length. The varying air flow is directed through an outlet chamber shaped to produce an oscillating or a pulsating flow.

First claim

What is claimed is:

1. A fluidic apparatus for generating a variable flow of pressurized fluid, comprising:
(a) a nozzle assembly defining a three-segment fluidic structure having an inlet segment, a power nozzle segment and an outlet segment all having lumens which are in fluid communication with one another and aligned on a central axis;
(b) a source of pressurized fluid in fluid communication with said inlet segment;
(c) said power nozzle segment having a large proximal inlet aperture and terminating distally in a smaller power nozzle aperture defined within said power nozzle segment, where the power nozzle aperture has a selected power nozzle width;
(d) said power nozzle segment having a selected first lumen having a first lumen area defined by the width of the power nozzle aperture and terminating distally in a selected second lumen having a second larger lumen area defined by a setback region having a selected setback width which is larger than said selected power nozzle width and is selected to control exhaust flow characteristics and which defines the beginning of said outlet segment;
(e) said power nozzle segment further including first and second control ports defining first and second control port chambers that are spaced apart from one another; wherein the first and second control port chambers are each in fluid communication with the power nozzle segment first lumen and are on opposite sides of the central axis within the power nozzle segment first lumen;
(f) said outlet segment having walls terminating at an exhaust aperture, the walls of the outlet segment being angled with respect to said central axis at a selected angle;
(g) wherein said first and second control port chambers are linked through an inertance loop tube providing fluid communication between the first and second control ports, said tube having a selected inertance tube length a selected inertance tube diameter, wherein (i) said selected inertance tube length, (ii) said selected inertance tube diameter and (iii) said selected setback width cooperate to initiate and control the frequency of bistable oscillation for exhaust gaseous fluid flow emitted from said exhaust aperture; and
said fluidic apparatus further comprising a two-mode bypass switch configured in said inertance loop to provide two states, a first open state, which maintains fluid communication in said inertance loop from said first control port to said second control port, thereby permitting the initiation and maintenance of bistable oscillating flow, and a second closed state, to selectively interrupt and prevent flow through said inertance loop, thereby permitting the initiation and maintenance of a non-oscillating pulsating flow mode;
wherein said setback width is 1.6 to 2.2 times the power nozzle aperture width and the outlet walls converge at a wall angle of 0° to −15°.

2. A fluidic apparatus for generating a variable flow of pressurized fluid, comprising:
(a) a nozzle assembly defining a three-segment fluidic structure having an inlet segment, a power nozzle segment and an outlet segment all having lumens which are in fluid communication with one another and aligned on a central axis;
(b) a source of pressurized fluid in fluid communication with said inlet segment;
(c) said power nozzle segment having a large proximal inlet aperture and terminating distally in a smaller power nozzle aperture defined within said power nozzle segment, where the power nozzle aperture has a selected power nozzle width;
(d) said power nozzle segment having a selected first lumen having a first lumen area defined by the width of the power nozzle aperture and terminating distally in a selected second lumen having a second larger lumen area defined by a setback region having a selected setback width which is larger than said selected power nozzle width and is selected to control exhaust flow characteristics and which defines the beginning of said outlet segment;
(e) said power nozzle segment further including first and second control ports defining first and second control port chambers that are spaced apart from one another; wherein the first and second control port chambers are each in fluid communication with the power nozzle segment first lumen and are on opposite sides of the central axis within the power nozzle segment first lumen;
(f) said outlet segment having walls terminating at an exhaust aperture, the walls of the outlet segment being angled with respect to said central axis at a selected angle;
(g) wherein said first and second control port chambers are linked through an inertance loop tube providing fluid communication between the first and second control ports, said tube having a selected inertance tube length a selected inertance tube diameter, wherein (i) said selected inertance tube length, (ii) said selected inertance tube diameter and (iii) said selected setback width cooperate to initiate and control the frequency of bistable oscillation for exhaust gaseous fluid flow emitted from said exhaust aperture; and
wherein said first and second control port chambers define transverse, laterally projecting segments terminating in first and second tubular stub fittings configured for connection with said inertance loop.

3. The fluidic apparatus of claim 2 , wherein said inertance loop is a continuous flexible tube segment connected to said first and second tubular stub fittings and providing fluid communication between the first and second control ports.

4. The fluidic apparatus of claim 3 , wherein the frequency of oscillation for the exhaust gaseous fluid flow emitted from said exhaust aperture is selected to be in the range of 18-20 Hz.

5. The fluidic apparatus of claim 1 , wherein the inlet segment has a smooth sinusoidal profile leading to said power nozzle aperture, resulting in a high velocity stream with minimal pressure drop.

6. The fluidic apparatus of claim 1 , wherein said inertance loop can be selectively opened and closed and wherein, when said inertance loop is closed said setback width is 1.6-2.2 times the power nozzle width to provide a pulsating mode which is reliably initiated and maintained.

7. A fluidic apparatus for generating a variable flow of pressurized fluid, comprising:
(a) a nozzle assembly defining a three-segment fluidic structure having an inlet segment, a power nozzle segment and an outlet segment all having lumens which are in fluid communication with one another and aligned on a central axis;
(b) a source of pressurized fluid in fluid communication with said inlet segment;
(c) said power nozzle segment having a large proximal inlet aperture and terminating distally in a smaller power nozzle aperture defined within said power nozzle segment, where the power nozzle aperture has a selected power nozzle width;
(d) said power nozzle segment having a selected first lumen having a first lumen area defined by the width of the power nozzle aperture and terminating distally in a selected second lumen having a second larger lumen area defined by a setback region having a selected setback width which is larger than said selected power nozzle width and is selected to control exhaust flow characteristics and which defines the beginning of said outlet segment;
(e) said power nozzle segment further including first and second control ports defining first and second control port chambers that are spaced apart from one another; wherein the first and second control port chambers are each in fluid communication with the power nozzle segment first lumen and are on opposite sides of the central axis within the power nozzle segment first lumen;
(f) said outlet segment having walls terminating at an exhaust aperture, the walls of the outlet segment being angled with respect to said central axis at a selected angle;
(g) wh

Assignees

• Bowles Fluidics Corp
• Dlhbowles Inc

Inventors

• Gopalan Shridhar
• Srinath Dharapuram N
• South Christopher

Classifications

• E01H1/0809 Primary

  Loosening or dislodging by blowing (combined with suction E01H1/0863; with steam E01H1/10; removing snow by blowing E01H5/106; cleaning rails by blowing E01H8/105, E01H8/125; removing fog by blowing E01H13/00; cleaning joints in road construction by blowing E01C23/0906); Drying by means of gas streams (combined with snow or ice melting E01H5/10) · CPC title

• B05B1/005

  Nozzles or other outlets specially adapted for discharging one or more gases · CPC title

• A01G1/125

  Human Necessities · mapped topic

• B05B1/08

  of pulsating nature, e.g. delivering liquid in successive separate quantities · CPC title

• A01G20/47

  Vacuum or blower devices · CPC title