Flat-Jet Nozzle With Star-Shaped Jet Director

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Solution Overview

Problem

Conventional flat jet nozzles have a tubular structure and large installation length, which is restrictive in certain applications and can prevent their use in cramped spaces, and the distance between guide plates and the outlet chamber affects the spray jet geometry unfavorably.

Innovation Solution

A flat jet nozzle with a disc-shaped jet director featuring a central opening and radially arranged, star-shaped openings with decreasing cross-sectional areas, reducing flow resistance and achieving a uniform velocity profile, allowing for a shorter design without compromising the spray jet pattern.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional tubular jet directors with long guide plates are used, then the spray jet pattern can be formed, but the installation length becomes large and disruptive

Engineering Contradiction:
Improvespray jet pattern formationVSAvoidinstallation length
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The jet director is segmented into multiple functional zones: a conical flow guidance zone at the inlet, a cylindrical mixing zone in the middle, and a conical outlet zone. This segmentation allows each zone to perform its specific function efficiently while reducing the overall length compared to conventional tubular designs. The flow guidance zone directs the liquid flow, the mixing zone allows turbulence and mixing, and the outlet zone shapes the final spray pattern.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a predominantly axial (one-dimensional) tubular structure to a multi-dimensional design with radial components. The jet director includes radial flow guidance surfaces and a cylindrical mixing zone that utilizes radial space, allowing the flow to be conditioned in multiple directions simultaneously. This dimensional expansion enables more effective flow conditioning in a shorter axial length.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If the distance between guide plates and outlet chamber is reduced, then the overall length is shortened, but the spray jet geometry is adversely affected

Engineering Contradiction:
Improveoverall lengthVSAvoidspray jet geometry
Core Design Contradiction:
Length of moving objectVSShape

Solution Approach 1:

The jet director performs preliminary flow conditioning actions within its compact structure before the liquid reaches the outlet chamber. The conical flow guidance zone pre-directs the flow, the cylindrical mixing zone pre-mixes and stabilizes the flow pattern, and the conical outlet zone pre-shapes the spray geometry. This preliminary action ensures that the spray jet geometry is properly formed even when the distance to the outlet chamber is minimized.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention merges multiple flow conditioning functions (flow direction, mixing, and spray shaping) into a single integrated jet director component. Instead of separate guide plates and chambers, the jet director combines all these functions in one compact element with zones performing different functions, eliminating the need for additional distance between components while maintaining proper spray geometry.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If conventional jet directors are used, then flow can be directed, but flow resistance is high due to long guide plates

Engineering Contradiction:
Improveflow direction controlVSAvoidflow resistance
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The jet director utilizes parameter changes in the flow path geometry to reduce flow resistance. The conical zones provide gradual expansion and contraction angles that minimize flow separation and turbulence losses. The cylindrical mixing zone maintains a constant cross-section that allows stable laminar or turbulent flow without additional resistance from changing geometry. These parameter optimizations reduce energy losses while maintaining effective flow direction control.

Inventive Principle:
Principle #35Parameter changes

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

The design results in a stable, uniform spray jet with a shortened overall length, enabling the nozzle's use in cramped spaces and providing a homogeneous cooling pattern suitable for applications like roll stands, with improved spray jet geometry and reduced friction losses.

Implementation Method 1

The jet director is designed as a disc with a central opening and further openings arranged in a star-shaped, rotationally symmetrical pattern around the central opening. The cross-sectional area of the openings increases from the outside toward the inside, generating a uniform velocity profile and reducing flow resistance.

Methodology Applied
Scientific EffectFluid flow distribution through multiple channels:

Implementation Method 2

The central opening and the outer cross-sections of the other openings, which decrease from the outside towards the middle, generate a dynamic pressure in front of the mouthpiece in the middle, i.e. along the longitudinal axis, which results in a substantially uniform velocity profile behind the jet director.

Methodology Applied
Scientific EffectDynamic pressure generation:

Data Source

PatentEP2992961B1Flat-jet nozzle and use of same
Publication Date: 2018.02.21 EVERTZ HYDROTECHN
  • EP2992961B1 patent drawingFigure 1~2

AI summary

The invention relates to a flat jet nozzle with a mouthpiece having an outlet opening and an outlet chamber with a cross-section tapering towards the outlet opening, and with a jet guide which, according to the invention, is designed as a disk having a central opening and further openings extending in a star-shaped rotationally symmetrical arrangement around the central opening, the cross-section of which decreases from the outside to the inside.