Blow-Suction Unit for Hot-Dip Coating Nozzle

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Solution Overview

Problem

Conventional continuous hot-dip galvanizing systems face issues with zinc dust formation in the trunk area, leading to surface defects and operational reliability concerns under fluctuating conditions, due to the reduction in flow cross-section caused by the arrangement of blow-suction units inside the trunk.

Innovation Solution

The device features a blow-suction unit with slot openings arranged externally on the trunk walls, allowing for a non-reducing flow cross-section, ensuring operational reliability and easy maintenance, with injection and suction units having staggered slot openings to create a tight gas curtain and effective vapor removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the blow-suction unit is arranged inside the trunk, then zinc vapor and dust can be removed, but the flow cross-section is reduced causing strip contact and damage

Engineering Contradiction:
Improvecoating process reliabilityVSAvoidflow cross-section
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The blow-suction unit is extracted from the interior of the trunk and mounted on the exterior surface. This allows the unit to remain functional for removing zinc vapor and dust while eliminating the obstruction to the flow cross-section, preventing strip contact and damage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The blow-suction unit is relocated from a three-dimensional interior space to a two-dimensional exterior surface of the trunk. This dimensional transition maintains the unit's functional capability while eliminating interference with the strip's passage through the trunk.

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

2Object-generated harmful factors

If the blow-suction unit is arranged inside the trunk, then atmospheric circulation can be created, but vibrations cause strip oscillation and contact with the unit

Engineering Contradiction:
Improvezinc dust formationVSAvoidoperational reliability under fluctuating conditions
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

By extracting the blow-suction unit from the interior to the exterior of the trunk, the unit remains stationary on the outer surface while still creating atmospheric circulation inside the trunk. This eliminates the risk of strip contact during vibrations while maintaining dust removal functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-generated harmful factors

If the blow-suction unit is arranged inside the trunk, then zinc vapor can be removed, but maintenance becomes difficult

Engineering Contradiction:
Improvezinc vapor accumulationVSAvoidmaintenance accessibility
Core Design Contradiction:
Object-generated harmful factorsVSEase of repair

Solution Approach 1:

The blow-suction unit is relocated to the exterior of the trunk where it is easily accessible for maintenance activities. The unit remains functional for zinc vapor removal while its external position allows straightforward inspection, cleaning, and repair without disassembly.

Inventive Principle:
Principle #2Taking out (Extraction)

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 prevents damage from contact with the trunk and ensures an operationally reliable coating process by maintaining flow cross-section and facilitating effective gas circulation and vapor removal, enhancing the quality of the coating process.

Implementation Method 1

the at least one injection unit has at least one slot opening (14.11) for injecting gas into the nozzle (13)

Methodology Applied
Scientific EffectGas flow:

Implementation Method 2

the at least one extraction unit has at least one slot opening (14.21) for extracting gas from the nozzle (13)

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 3

injection and suction units having staggered slot openings to create a tight gas curtain and effective vapor removal

Methodology Applied
Scientific EffectGas mixing and curtain formation:

Data Source

PatentEP3591088B1Device for hot dip coating of a metal strip
Publication Date: 2020.11.11 THYSSENKRUPP AG
  • EP3591088B1 patent drawingFigure 1
  • EP3591088B1 patent drawingFigure 2
  • EP3591088B1 patent drawingFigure 3

AI summary

The invention relates to a device (10) for hot-dip coating a metal strip (1), comprising a continuous furnace for passing and heating the metal strip (1), a vessel (11) filled with molten metal (11.1) arranged downstream of the continuous furnace in the direction of travel (L) of the metal strip (1), and a nozzle (13) arranged between the continuous furnace and the vessel (11) for passing and introducing the metal strip (1) into the molten metal (11.1) in the vessel (11), wherein the nozzle (13) comprises a blow-suction unit (14) with at least one injection unit (14.1) and at least one extraction unit (14.2), which are arranged on at least one wall (13.1), in particular on two opposing walls (13.1) of the nozzle (13), wherein the at least one extraction unit (14.2) is arranged downstream of the at least one injection unit (14.1) in the direction of travel (L) of the metal strip (1). The injection unit (14.1) is arranged, wherein the at least one injection unit (14.1) at least one slot opening (14.11) for blowing gas into the nozzle (13) and the at least one extraction unit (14.2) having at least one slot opening (14.21) for extracting gas from the nozzle (13), wherein the slot opening (14.11, 14.21) extends transversely to the direction of travel (L) of the metal belt (1), wherein the at least one slot opening (14.11, 14.21) of the blowing unit (14.1) and/or extraction unit (14.2) is arranged such that it is substantially flush with the wall (13.1) of the nozzle (13) or partially projects into the nozzle (13).