Vacuum Ejector With Multi-Nozzle Drive Stage And Booster

A method of generating a vacuum from a source of pressurized fluid comprising:

• supplying the pressurized fluid simultaneously to a primary drive nozzle array having at least two drive nozzles so as to generate respective drive fluid jets from each of the drive nozzles and to a booster nozzle so as to generate a booster drive fluid jet;
• directing the drive fluid jets from each of the drive nozzles together substantially directly into an inlet of a common drive outlet flow passage located downstream of the drive nozzle array and directing the booster drive fluid jet separately substantially directly into the inlet of a booster outlet flow passage;
• generating a vacuum upstream of the inlet of the common outlet flow passage by entraining air or other medium from a volume surrounding the drive fluid jets into the drive jet flow to evacuate a connected volume to be evacuated down to a drive vacuum pressure;
• and
• generating a vacuum upstream of the inlet of the booster outlet flow passage by entraining said air or other medium from a volume surrounding the booster drive fluid jet into the booster jet flow to evacuate the connected volume to be evacuated down to a booster vacuum pressure which is lower than the drive vacuum pressure.

A booster module for reducing the vacuum pressure obtainable by a primary ejector module, the primary ejector module comprising:

• a primary ejector having a first, drive stage comprising a drive nozzle array for generating drive jet flow of drive fluid from a pressurized fluid source, the drive nozzle array including two or more nozzles arranged to feed respective drive fluid jets together substantially directly into a common outlet of the drive stage so as to entrain air or other medium in a volume surrounding the drive fluid jets into the drive jet flow in order to generate a vacuum across the drive stage;
• a primary pressurized fluid chamber for receiving pressurized fluid from a pressurized fluid source via a primary pressurized fluid port and supplying said pressurized fluid to a drive nozzle array of the primary ejector;
• a primary vacuum chamber substantially enclosing said drive stage and arranged such that said air or other medium in the primary vacuum chamber will be evacuated by the vacuum generated across the drive stage, the primary vacuum chamber having a primary evacuation port for connection to the volume to be evacuated;
• and
• a primary exit port through which the drive fluid and the entrained air or other medium ejected from the primary ejector will be expelled,
• the booster module comprising:
• a booster ejector connected in parallel with said primary ejector for simultaneously generating a vacuum across a booster stage, the booster ejector comprising a booster nozzle for generating a booster drive fluid jet from said same pressurized fluid source and feeding said booster drive fluid jet substantially directly into an outlet of the booster stage so as to entrain said air or other medium in a volume surrounding the booster drive fluid jet into the booster jet flow in order to generate a vacuum across the booster stage,
• a booster pressurized fluid chamber for receiving pressurized fluid from the pressurized fluid source via a booster pressurized fluid port and supplying said pressurized fluid to the booster nozzle;
• a booster vacuum chamber substantially enclosing said booster stage and arranged such that said air or other medium in the booster vacuum chamber will be evacuated by the vacuum generated across the booster stage, the booster vacuum chamber having a booster evacuation port for connection to the volume to be evacuated;
• and
• a booster exit port through which the drive fluid and the entrained air or other medium ejected from the booster ejector will be expelled, wherein
• said booster evacuation port is adapted for connection to the volume to be evacuated and the booster vacuum chamber further includes a primary-booster port adapted for connection to said primary evacuation port, for connecting the primary ejector module to the volume to be evacuated via the booster module.

A modular ejector kit comprising:

• a primary ejector module comprising:
• a primary ejector having a first, drive stage comprising a drive nozzle array for generating drive jet flow of drive fluid from a pressurized fluid source, the drive nozzle array including two or more nozzles arranged to feed respective drive fluid jets together substantially directly into a common outlet of the drive stage so as to entrain air or other medium in a volume surrounding the drive fluid jets into the drive jet flow in order to generate a vacuum across the drive stage;
• a primary pressurized fluid chamber for receiving pressurized fluid from a pressurized fluid source via a primary pressurized fluid port and supplying said pressurized fluid to a drive nozzle array of the primary ejector;
• a primary vacuum chamber substantially enclosing said drive stage and arranged such that said air or other medium in the primary vacuum chamber will be evacuated by the vacuum generated across the drive stage, the primary vacuum chamber having a primary evacuation port for connection to the volume to be evacuated;
• and
• a primary exit port through which the drive fluid and the entrained air or other medium ejected from the primary ejector will be expelled;
• and
• a booster module comprising:
• a booster ejector connected in parallel with said primary ejector for simultaneously generating a vacuum across a booster stage, the booster ejector comprising a booster nozzle for generating a booster drive fluid jet from said same pressurized fluid source and feeding said booster drive fluid jet substantially directly into an outlet of the booster stage so as to entrain said air or other medium in a volume surrounding the booster drive fluid jet into the booster jet flow in order to generate a vacuum across the booster stage,
• a booster pressurized fluid chamber for receiving pressurized fluid from the pressurized fluid source via a booster pressurized fluid port and supplying said pressurized fluid to the booster nozzle;
• a booster vacuum chamber substantially enclosing said booster stage and arranged such that said air or other medium in the booster vacuum chamber will be evacuated by the vacuum generated across the booster stage, the booster vacuum chamber having a booster evacuation port for connection to the volume to be evacuated;
• and
• a booster exit port through which the drive fluid and the entrained air or other medium ejected from the booster ejector will be expelled, wherein:
• said booster evacuation port is adapted for connection to the volume to be evacuated and the booster vacuum chamber further includes a primary-booster port adapted for connection to said primary evacuation port, for connecting the primary ejector module to the volume to be evacuated via the booster module.