Supersonic Nozzle Pressure Control via Calibration Curve

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Solution Overview

Problem

In steel production, supersonic nozzles in metallurgical vessels often operate suboptimally due to uncertainties in inlet pressure and temperature, leading to nozzle wear and inefficiencies, as exact pressure loss between the gas supply station and the nozzle is difficult to determine.

Innovation Solution

A method involving a self-sufficient measuring device to record inlet pressure and temperature over time, allowing for the creation of a calibration curve that enables precise control of the gas supply pressure to maintain the nozzle at its ideal operating point, thereby determining and regulating the pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the supersonic nozzle is operated without precise pressure control, then the device complexity is reduced, but the nozzle wear increases and service life decreases

Engineering Contradiction:
Improvenozzle service lifeVSAvoidmeasurement and control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-determining the pressure loss value between the gas supply station and the supersonic nozzle through calibration measurements. This calibration data is stored and used for future operational control, allowing the nozzle to be operated at its optimal design point without requiring complex real-time measurement systems. The pressure loss is determined in advance and used to calculate the required supply pressure to achieve the desired inlet pressure at the nozzle.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by using the calibrated pressure loss value to dynamically adjust the gas supply pressure parameters. The control system calculates the required supply pressure based on the predetermined pressure loss and the desired nozzle inlet pressure, allowing the system to operate the nozzle at optimal conditions while accounting for variations in operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the inlet pressure at the supersonic nozzle is not precisely controlled, then the ease of operation is improved, but the gas flow efficiency decreases and the process becomes unstable

Engineering Contradiction:
Improvegas flow efficiencyVSAvoidoperational control difficulty
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by pre-determining the pressure loss value between the gas supply station and the supersonic nozzle through calibration measurements. This calibration data is stored and used for future operational control, allowing the nozzle to be operated at its optimal design point without requiring complex real-time measurement systems. The pressure loss is determined in advance and used to calculate the required supply pressure to achieve the desired inlet pressure at the nozzle.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies feedback by using the calibrated pressure loss relationship to continuously adjust the gas supply pressure based on the desired nozzle inlet pressure. The control system monitors the actual conditions and adjusts the supply pressure to maintain optimal operation, ensuring stable and efficient gas flow through the supersonic nozzle.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If the pressure loss is not accurately determined, then the measurement system is simplified, but the nozzle operates away from its ideal operating point causing wear

Engineering Contradiction:
Improvenozzle operating point precisionVSAvoidpressure measurement and calibration system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-determining the pressure loss value between the gas supply station and the supersonic nozzle through calibration measurements. This calibration data is stored and used for future operational control, allowing the nozzle to be operated at its optimal design point without requiring complex real-time measurement systems. The pressure loss is determined in advance and used to calculate the required supply pressure to achieve the desired inlet pressure at the nozzle.

Inventive Principle:
Principle #10Preliminary action

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 approach ensures the supersonic nozzle operates at its optimal point, reducing wear and maintaining efficient gas flow, leading to stable and reproducible metallurgical processes with extended nozzle service life.

Implementation Method 1

In such a blowing lance head there are usually a number of convergent-divergent nozzles which are arranged at predetermined angles and which accelerate the gas to supersonic speed

Methodology Applied
Scientific EffectSupersonic flow acceleration through Laval nozzle: De Laval Nozzle

Implementation Method 2

the gas in the divergent nozzle part of the supersonic nozzle cools down to about -100° C. due to the expansion of the gas, so that the nozzle or the blowing lance head is also cooled on the gas side by the expanded gas

Methodology Applied
Scientific EffectGas expansion cooling: Adiabatic Cooling

Implementation Method 3

measuring the inlet pressure (P) of a gas in the at least one nozzle (18)

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 4

determining a calibration curve for the inlet pressure from the measured inlet pressure and the measured feed pressure

Methodology Applied
Scientific EffectPressure loss determination: Pressure Drop

Data Source

PatentEP2694691B1Method for operating at least one supersonic nozzle in a metallurgical vessel, method for determining a pressure loss and system for determining operating parameters of at least one supersonic nozzle
Publication Date: 2015.02.18 SMS GROUP GMBH
  • EP2694691B1 patent drawingFigure 1~2
  • EP2694691B1 patent drawingFigure 3

AI summary

The present invention relates to a method for operating at least one supersonic nozzle (40) in a metallurgical vessel (3), comprising the following steps: measuring the inlet pressure (po(t)) of a gas into a supersonic nozzle (40); simultaneously measuring the feed pressure (pvs(t)) of the gas at a gas feed station (1) arranged at a distance from the supersonic nozzle (40); determining a calibration curve (po(t)=f(pvs(t))) from the measured inlet pressure (po(t)) and the measured feed pressure (pvs(t)); and operating the supersonic nozzle (40) in the metallurgical vessel at a predefined inlet pressure (po) by regulating the feed pressure (pvs) on the basis of the determined calibration curve.