Hot-Dip Coating Nozzle With Rotatable Carrier Plate

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Solution Overview

Problem

Hot-dip coating systems face challenges with coating faults due to metal evaporation and dust deposition in the nozzle, leading to quality issues, and existing solutions are either expensive, complex, or inefficient for maintenance and space requirements.

Innovation Solution

A nozzle design with a common carrier plate for suction and blowing units, easily movable for maintenance, and a frame structure for stiffening and sealing, along with insulating materials and defined positioning mechanisms, to facilitate quick maintenance and reduce metal dust deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a comb-like seal structure with numerous injection and extraction openings is used to prevent zinc vapor escape, then sealing effectiveness is improved, but device complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The nozzle is divided into functionally independent segments: a fixed body and a rotatable carrier plate with injection/extraction units. This segmentation allows the sealing mechanism to be simplified from a complex comb-like structure to a basic rotary shutter design, reducing manufacturing complexity while maintaining sealing effectiveness through controlled opening/closing of the carrier plate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The carrier plate is designed to be rotatable relative to the nozzle body, transforming the static comb-like seal into a dynamic system. The carrier plate can rotate between an open position (for maintenance access) and a closed position (for operational sealing), providing adaptive sealing control without requiring complex fixed structures.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If a permanently installed complex sealing device is used to prevent metal dust deposition, then product quality is improved, but maintenance difficulty and time increase

Engineering Contradiction:
Improveproduct qualityVSAvoidmaintenance difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of repair

Solution Approach 1:

The rotatable carrier plate enables dynamic access to the injection and extraction units. During operation, the carrier plate closes to maintain sealing and prevent metal dust deposition on the steel strip. During maintenance, the carrier plate can be rotated to an open position, providing easy access to all injection and extraction components without requiring complete nozzle disassembly.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The injection and extraction units are extracted from the fixed nozzle body and mounted on the separable carrier plate. This extraction allows maintenance personnel to easily remove and service these components by simply rotating the carrier plate to the open position, significantly reducing maintenance time and difficulty while maintaining product quality during operation.

Inventive Principle:
Principle #2Taking out (Extraction)

3Area of stationary object

If the nozzle structure is made compact to reduce space requirements, then footprint is reduced, but accessibility for maintenance work deteriorates

Engineering Contradiction:
ImprovefootprintVSAvoidaccessibility for maintenance
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

The rotatable carrier plate provides a compact yet accessible design. When closed, the carrier plate maintains a compact nozzle structure with minimal footprint. When opened for maintenance, the carrier plate rotates to provide wide accessibility to all injection and extraction units, eliminating the need for complex disassembly procedures despite the compact overall structure.

Inventive Principle:
Principle #15Dynamics

4Reliability

If protective gas is used to prevent oxidation of the steel strip, then adhesion of coating is improved, but zinc vapor condensation and dust formation increase

Engineering Contradiction:
Improvecoating adhesionVSAvoidmetal dust deposition
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

Injection units deliver protective gas streams into the nozzle to prevent steel strip oxidation and ensure coating adhesion. Extraction units simultaneously remove zinc vapors and prevent their condensation on the steel strip. The pneumatic system balances protective gas injection with vapor extraction to maintain coating quality while minimizing metal dust deposition.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The nozzle provides different local gas atmosphere conditions: protective gas is injected in areas where the steel strip is present to prevent oxidation, while extraction units create zinc vapor-free zones near the strip surface. This local quality control ensures coating adhesion while preventing metal dust formation at critical locations.

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

Enables simple and quick maintenance, reduces metal dust deposition, and improves sealing and thermal insulation, ensuring efficient operation and product quality while minimizing space and cost.

Implementation Method 1

the support plate closes an opening in the nozzle... achieves a relatively good seal against rising zinc vapors and the overlying gas atmosphere

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 2

A nozzle design with a common carrier plate for suction and blowing units, easily movable for maintenance, and a frame structure for stiffening and sealing, along with insulating materials

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3638821B1Nozzle for a hot-dip coating system
Publication Date: 2021.01.13 THYSSENKRUPP AG
  • EP3638821B1 patent drawingFigure 1
  • EP3638821B1 patent drawingFigure 2~3

AI summary

The invention relates to a nozzle (9) for a hot-dip coating system for a flat product, said nozzle extending from the outlet of a continuous furnace into a melt below the coating bath level and isolating the flat product from the surroundings. At least one suction unit (3) and a blowing unit (1) are provided. The invention is characterized in that the blowing unit (1) and the suction unit (3) are provided on a common support plate (8), the support plate (8) is connected to the nozzle (9) along one edge via at least one joint (10), and the support plate (8) can be moved into a closed position, in which the support plate (8) closes an opening on the nozzle (9), and into an open position.