Slit Nozzle Liquid Removal for Steel Sheet Gas Jet Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional liquid removal methods for steel sheets require wringer rolls and dryers, leading to increased maintenance costs and inefficiencies due to liquid accumulation and equipment wear.
Innovation Solution
A liquid removal device using a slit nozzle that jets gas onto the steel sheet surface, with a gap measurement and adjustment mechanism to ensure optimal gas flow, eliminating the need for wringer rolls and dryers by maintaining a precise gap and nozzle configuration to suppress interference from outside air suction flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wringer rolls and dryers are used to remove liquid from steel sheets, then liquid removal function is provided, but equipment maintenance cost increases and device complexity increases
Solution Approach 1:
The invention extracts and eliminates the wringer rolls and dryers from the liquid removal system, replacing them with a gas jet device that directly jets gas onto the steel sheet surface to remove liquid, thereby simplifying the equipment structure while maintaining the liquid removal function
Solution Approach 2:
The invention replaces the mechanical wringer rolls and thermal dryers with a gas jet system that uses fluid dynamics (Coanda effect and shear stress) to remove liquid, substituting mechanical and thermal methods with a pneumatic approach
2Duration of action of moving object
If wringer rolls are used for a long period, then liquid removal function is maintained, but wear occurs causing gaps that broaden the range of liquid remaining on the steel sheet
Solution Approach 1:
The gas jet device uses inexpensive gas (air) as the working medium that does not wear out, replacing the expensive rubber layers of wringer rolls that require periodic replacement due to wear, thereby maintaining reliable liquid removal effectiveness throughout the service period
3Productivity
If liquid remains on the steel sheet surface after wringer rolls, then the process continues, but the drier cannot sufficiently blow off the liquid
Solution Approach 1:
The gas jet device performs preliminary liquid removal by jetting gas onto the steel sheet surface before any drying process, removing the bulk of the liquid through shear stress and Coanda effect, which prepares the surface for more effective subsequent drying if needed
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
Effectively removes liquid from steel sheets without wringer rolls and dryers, reducing maintenance costs and ensuring efficient liquid removal by maintaining a stable gas flow and pressure, thus preventing liquid accumulation.
Implementation Method 1
a slit nozzle that jets gas to the surface of the sheet-like member
Implementation Method 2
gas pressure inside the slit nozzle is defined as nozzle pressure Pn [KPa]
Implementation Method 3
suppress interference from outside air suction flows
Data Source
AI summary
There is provided a liquid removal device that removes liquid attached to a surface of a steel sheet, the device including a slit nozzle that jets gas to the surface of the sheet, the slit nozzle being installed so as to jet gas from a downstream side toward an upstream side in a movement direction of the sheet that moves relatively to the slit nozzle and being configured in a manner that a jet angle θ, a back face inclination angle β, and a back face length L of a nozzle back face of the slit nozzle satisfy, β+θ≥60° and L≥20mm, and a gap h between a jetting port of the slit nozzle and the sheet, a slit width d, and nozzle pressure Pn of the slit nozzle satisfy the following relationship: Pn≥2.0×1010(h/d)0.6{1/(1+exp(β+θ−58)+1}−4L−7.