Submerged Entry Nozzle With Extended Bottom Slits
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Solution Overview
Problem
Existing submerged entry nozzles cause undesired wear and turbulence in metal streams during casting due to radial outflow, leading to uneven solidification and increased turbulences, which are not effectively addressed by prior solutions like cage-like barriers or electromagnetic stirrers.
Innovation Solution
The nozzle design is modified by extending the outlet openings into the bottom section, allowing a vertical flow component and angular momentum, with slit-like openings inclined to reduce redirection sharpness and enhance angular momentum, enabling a smoother metal flow with a vertical twist.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the outlet openings are arranged radially along the wall portion of the central section, then the melt can flow out through the outlet ports, but the metal stream hits the adjacent wall of the ingot mold causing undesired wear
Solution Approach 1:
The outlet openings are extended in the longitudinal direction of the nozzle into the bottom section, transforming the flow direction from purely radial (horizontal) to a combination of radial and axial (vertical) components. This dimensional change in flow trajectory allows the metal stream to bypass the mold wall while still maintaining effective melt delivery.
Solution Approach 2:
Instead of having the melt flow out horizontally and then turn downward, the design reverses the sequence by first directing melt axially downward through the extended outlet openings in the bottom section, then allowing it to spread radially. This inversion of flow sequence prevents direct impact on the mold wall.
2Object-affected harmful factors
If a cage-like intermediate barrier system is installed between the outlet opening and the mold, then direct impact of metal stream onto the mold is avoided, but turbulences of the metal melt are increased causing arbitrary solidification
Solution Approach 1:
The harmful function of the cage-like barrier system is extracted and eliminated. Instead of using a physical barrier to prevent mold impact, the nozzle geometry itself is modified to inherently direct the flow away from the mold wall, removing the source of turbulence-generating obstacles.
Solution Approach 2:
The extended bottom section of the nozzle acts as an intermediary flow guide, replacing the need for a cage-like barrier. This smooth geometric transition mediates between the outlet opening and the mold, directing flow away from the mold wall without creating turbulence.
3Stability of the object's composition
If electromagnetic stirrer is installed around the metal stream, then angular momentum is given to the strand, but corresponding installation and investment is required and no real advantages are achieved for opposite twist
Solution Approach 1:
The nozzle itself serves the function of generating angular momentum in the metal stream through its geometric design. The extended outlet openings in the bottom section inherently impart a twisting motion to the flowing melt, eliminating the need for external electromagnetic stirrers or other complex control devices.
Solution Approach 2:
The mechanical/electromagnetic stirrer system is replaced by a purely geometric flow control mechanism. The shape and orientation of the outlet openings in the bottom section create the desired flow pattern through fluid dynamics alone, without requiring external energy input or complex control systems.
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 reduces turbulences and collisions with the mold, promoting a continuous, homogeneous metal flow with reduced wear and improved solidification by providing a vertical flow component and angular momentum to the metal stream.
Implementation Method 1
The outlet openings are designed as long slits which continuously extend from a position at a distance to the bottom into the bottom. The slits have side walls extending in a plane which is parallel to a plane comprising a central longitudinal axis of the nozzle, or in a plane arranged at an angle between 5 and 45 degrees to such a plane.
Implementation Method 2
said slits have a length, with is about 10 times its width... The lower part of outlet slits extends along said horizontal bottom, thus giving the melt a strong vertical and twist component when leaving these bottom openings.
Data Source
AI summary
An exemplary embodiment relates to a submerged entry nozzle (SEN) for use in metallurgy, in particular for transporting a metal melt from a first metallurgical unit to a second metallurgical unit, for example during slab production in continuous casting of ferrous and non-ferrous melts. The SEN is called nozzle hereinafter.