Convergent-Divergent Snow Lance Nozzle for Low-Air Snowmaking

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Solution Overview

Problem

Existing snow lances require high energy input and are limited to producing artificial snow at low temperatures, making them inefficient for higher temperature conditions.

Innovation Solution

A convergent-divergent nucleator nozzle with a specific geometry that reduces energy input by optimizing the cross-sectional area ratio and utilizing compressed air effectively to cool water droplets, allowing for ice nuclei production at higher temperatures with reduced air consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional nucleator nozzles are used to generate ice nuclei, then artificial snow can be produced, but high energy input and high compressed air consumption are required

Engineering Contradiction:
Improveartificial snow production capabilityVSAvoidenergy input and compressed air consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the geometric parameters of the nozzle channel, specifically the cross-sectional area ratio between the outlet opening and the narrowest section (A_out/A_min ≥ 4:1, preferably ≥ 9:1). This parameter change enables the nozzle to generate sufficient ice nuclei with much lower compressed air consumption, directly resolving the contradiction between snow production capability and energy input requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a convergent-divergent nozzle design where the channel cross-section dynamically changes along the flow direction. The channel narrows to a minimum cross-section and then expands to the outlet, creating optimal flow conditions for ice nucleus generation. This dynamic geometric configuration allows efficient ice nucleus formation at lower energy input compared to conventional nozzles with constant or simple tapered profiles.

Inventive Principle:
Principle #15Dynamics

2Productivity

If conventional snow lances are used, then artificial snow can be produced at low temperatures, but they cannot operate effectively at higher temperatures

Engineering Contradiction:
Improveartificial snow production capabilityVSAvoidtemperature range for operation
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent changes the geometric parameters of the nozzle, specifically the cross-sectional area ratio (A_out/A_min ≥ 4:1, preferably ≥ 9:1), which fundamentally alters the flow dynamics and cooling efficiency. This parameter change enables the system to generate sufficient ice nuclei even when the water temperature is as high as 10°C, extending the operational temperature range from conventional -3°C to -4°C limits.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary cooling of water droplets within the nozzle channel before they exit. The extended residence time in the convergent-divergent channel allows compressed air to cool the water droplets to sub-zero temperatures prior to ice nucleus generation. This preliminary cooling action enables effective snow production at higher ambient temperatures where conventional nozzles fail.

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If the compressed air consumption is reduced, then energy input decreases, but the effectiveness of ice nuclei generation is compromised

Engineering Contradiction:
Improvecompressed air consumptionVSAvoidice nuclei generation effectiveness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the geometric parameter of the nozzle channel cross-sectional area ratio to at least 4:1, preferably at least 9:1. This geometric parameter change creates optimal flow conditions that maximize ice nuclei generation efficiency, allowing the system to maintain high effectiveness with significantly reduced compressed air consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a convergent-divergent nozzle design that dynamically optimizes the flow of compressed air and water droplets. The narrowing and expansion of the channel creates controlled turbulence and cooling effects that enhance ice nucleus formation efficiency, ensuring reliable performance even at lower air consumption levels.

Inventive Principle:
Principle #15Dynamics

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 solution enables the production of artificial snow with significantly reduced energy input and extends the temperature range for snow production, achieving a 50% reduction in air consumption and allowing snow production up to 10°C water temperature.

Implementation Method 1

Water introduced into the nozzle channel through a water inlet opening is accelerated by compressed air

Methodology Applied
Scientific EffectCompressed air acceleration: Pressure Gradient

Implementation Method 2

The geometry of the nozzle is selected in the widening second section in such a way that a negative pressure is established in this section during operation. As a result, the temperature of the compressed air in the nozzle is lower

Methodology Applied
Scientific EffectNegative pressure cooling: Adiabatic Cooling

Implementation Method 3

The geometry causes shocks to form in the exiting medium after the outlet opening due to the pressure equalization

Methodology Applied
Scientific EffectShock wave formation: Shock Wave

Implementation Method 4

This so-called germination creates snow from the cooling water droplets

Methodology Applied
Scientific EffectPhase change to ice: Freezing

Data Source

PatentEP2232171B1Snow lance and method for producing artificial snow
Publication Date: 2019.03.27 BAECHLER TOP TRACK
  • EP2232171B1 patent drawingFigure 1
  • EP2232171B1 patent drawingFigure 2~3
  • EP2232171B1 patent drawingFigure 4~5

AI summary

A nucleator nozzle (20) for producing ice nuclei is designed as convergent-divergent nozzle. The nozzle channel (25) has a section (27) that is widening. The ratio of the cross-sectional area of the outlet opening (23) to the cross-sectional area of the nozzle channel (25) in the region of the nucleus diameter (26) is at least approximately 4:1. A snow lance (1) having at least one nucleator nozzle (20) and having at least one water nozzle (30; 30') is designed such that water droplets (32) produced by the water nozzle (30; 30') pass through a droplet path (31; 31') of at least 20 cm until they reach ice nuclei (28) from the nucleator nozzle (20) in a germination zone E.