Ejector Flow Restrictor for Pressure Recovery

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Solution Overview

Problem

Existing ejectors may malfunction and fail to suck a second fluid effectively if the pressure of the fluid passing through the diffuser is not sufficiently raised.

Innovation Solution

The ejector design includes a nozzle for ejecting a first fluid, a suction chamber to suck a second fluid using the pressure decrease caused by the first fluid's ejection, a diffuser to raise the pressure of both fluids, and at least one flow restrictor located downstream from the diffuser, comprising upstream and downstream disc-shaped orifice plates with specific aperture ratios to ensure proper pressure increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If the ejector is designed with a diffuser to raise pressure, then the pressure of the fluid should increase, but the pressure downstream from the diffuser may still be insufficient in compact designs

Engineering Contradiction:
Improvepressure of fluidVSAvoidejector size
Core Design Contradiction:
Stress or pressureVSVolume of moving object

Solution Approach 1:

A flow restrictor is introduced as an intermediary component between the diffuser and the discharge to enhance pressure recovery. The flow restrictor creates a controlled pressure drop that facilitates back-pressure on the diffuser outlet, improving the overall pressure of the discharged fluid without significantly increasing the ejector's volume.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the flow parameters by introducing a flow restrictor that creates a specific pressure drop pattern. This parameter change in the flow characteristics allows for improved pressure recovery in the diffuser section, enabling compact ejector designs to achieve sufficient discharge pressure.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the ejector malfunctions, then it fails to suck the second fluid effectively, but adding components to prevent malfunction increases device complexity

Engineering Contradiction:
Improveejector functionalityVSAvoidejector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flow restrictor serves as a simple intermediary component that prevents malfunction by ensuring proper pressure conditions in the diffuser. This single added component significantly improves reliability by preventing the common failure mode where insufficient pressure rise causes the ejector to malfunction, without substantially increasing overall device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stress or pressure

If the pressure downstream from the diffuser is low, then the ejector cannot function properly, but increasing pressure requires larger components

Engineering Contradiction:
Improvepressure downstream from diffuserVSAvoiddiffuser length
Core Design Contradiction:
Stress or pressureVSLength of stationary object

Solution Approach 1:

The flow restrictor acts as a mediator that creates a pressure drop downstream, which in turn creates back-pressure on the diffuser outlet. This back-pressure effect allows the diffuser to achieve sufficient pressure rise in a shorter length, as the flow restrictor essentially 'pushes back' to enhance the pressure recovery process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of trying to increase pressure by making the diffuser longer, the invention uses the opposite approach by placing a flow restrictor downstream. This restrictor creates a pressure drop that generates back-pressure, effectively increasing the pressure downstream from the diffuser in a compact configuration rather than extending the diffuser length.

Inventive Principle:
Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration ensures that the ejector functions properly by sufficiently raising the pressure of the fluid passing through the diffuser, allowing for effective suction of the second fluid, even in compact designs where pressure downstream from the diffuser may be lower.

Implementation Method 1

a suction chamber configured to suck a second fluid using a pressure decrease caused by ejection of the first fluid through the nozzle

Methodology Applied
Scientific EffectPressure decrease: Pressure Drop

Implementation Method 2

a diffuser configured to discharge the first fluid ejected through the nozzle and the second fluid sucked into the suction chamber while raising a pressure of the first fluid and the second fluid

Methodology Applied
Scientific EffectPressure raising: Pressure Increase

Data Source

PatentEP3351805B1Ejector and vacuum generation device with same
Publication Date: 2025.05.21 TLV CO LTD
  • EP3351805B1 patent drawingFigure 1
  • EP3351805B1 patent drawingFigure 2
  • EP3351805B1 patent drawingFigure 3

AI summary

An ejector (40) includes a nozzle (41) that ejects a first fluid, a suction chamber (42) that sucks a second fluid using a pressure decrease caused by ejection of the first fluid through the nozzle (41), a diffuser (43) that discharges the first fluid ejected through the nozzle (41) and the second fluid sucked into the suction chamber (42) while raising a pressure of the first fluid and the second fluid, and at least one orifice plate (44) located downstream from the diffuser (43).