Injector Nozzle Dual Conical Sections Pressure Fluctuations

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Solution Overview

Problem

Conventional injector nozzles in agricultural engineering face challenges in maintaining a constant mixing ratio between the liquid to be sucked in and the carrier liquid due to pressure fluctuations, making them unsuitable for use in crop protection applications.

Innovation Solution

The injector nozzle design features two conical sections within the injector chamber, with the second section having a larger cone angle than the first, ensuring an essentially constant mixing ratio even with changes in pressure, and includes a mixing chamber for thorough mixing and a slit-shaped outlet for efficient spray distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional injector nozzles are used, then the device complexity is low, but the mixing ratio stability deteriorates due to pressure fluctuations

Engineering Contradiction:
Improvemixing ratio stabilityVSAvoidinjector chamber structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The injector chamber is divided into two distinct conical sections with different cone angles. The first conical section has a smaller cone angle and the second conical section has a larger cone angle. This segmentation allows each section to perform a specific function in controlling the mixing ratio, thereby improving reliability without requiring complex external control systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the geometric parameters of the injector chamber by implementing two conical sections with different cone angles. This parameter change creates a flow pattern that compensates for pressure fluctuations, maintaining stable mixing ratio across varying operating conditions without adding device complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If pressure of the carrier liquid varies, then the device operation is simple, but the mixing ratio consistency deteriorates

Engineering Contradiction:
Improvemixing ratio consistencyVSAvoidcarrier liquid pressure stability
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The dual conical section design changes the geometric parameters of the injector chamber to create a flow pattern that is less sensitive to pressure variations. The different cone angles create varying flow velocities and pressures at different sections, compensating for inlet pressure fluctuations and maintaining consistent mixing ratio.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The conical geometry creates dynamic flow conditions where the varying cross-sectional area along the flow direction automatically adjusts the flow rates of both carrier liquid and sucked-in liquid in response to pressure changes, maintaining dynamic equilibrium in the mixing ratio.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a single conical section is used, then the device complexity is low, but the mixing performance deteriorates under varying pressure conditions

Engineering Contradiction:
Improvemixing performanceVSAvoidnumber of conical sections
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The injector chamber is segmented into two conical sections, each with a specific cone angle optimized for particular functions. The first section handles initial mixing while the second section refines the mixing process, improving overall mixing performance under varying pressure conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the injector chamber are given different geometric properties (different cone angles) to perform different functions. The first conical section with smaller angle provides gentle mixing while the second section with larger angle enhances turbulence and mixing intensity, creating local quality variations that improve overall mixing performance.

Inventive Principle:
Principle #3Local quality

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 design allows for a reliable and simple crop protection sprayer that maintains a consistent mixing ratio between the carrier liquid and the sucked-in liquid, even with varying pressures, making it suitable for portable sprayers and ensuring effective application of crop protection agents.

Implementation Method 1

Injector nozzles are a well-known principle and operate according to the so-called Venturi principle. A jet of liquid enters an injector chamber, creating a vacuum within the chamber and then drawing in gas or air.

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Implementation Method 2

The described injector nozzle is designed for generating foam, utilizing the effect of cavitation.

Methodology Applied
Scientific EffectCavitation: Cavitation

Data Source

PatentEP2883618B1Injector nozzle
Publication Date: 2020.10.28 LECHLER GMBH & CO KG
  • EP2883618B1 patent drawingFigure 1~2
  • EP2883618B1 patent drawingFigure 3~6

AI summary

The invention relates to an injector nozzle for drawing in liquids, comprising an injector chamber, a liquid inlet opening for a pressurized carrier fluid which opens into the injector chamber, a liquid intake opening for a liquid to be drawn in which opens into the injector chamber 42, wherein the injector chamber has, downstream of the liquid inlet opening, a first conically expanding section and a second conically expanding section, wherein the second conically expanding section adjoins the first conically expanding section and the second conically expanding section has a larger cone angle than the first conically expanding section.