Hot gas generator for heating gas and system for asphalt manufacture with such a hot gas generator

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Solution Overview

Problem

Hot gas generators used in asphalt production emit high levels of pollutants, particularly hydrocarbon compounds and fine particles, which are not effectively reduced by existing technologies.

Innovation Solution

The hot gas generator operates in a countercurrent process with a flow deflection unit that redirects the gas flow to prevent direct linear paths, enhancing combustion efficiency and reducing pollutant emissions by orienting heat propagation opposite to gas flow direction, and using a swirler to create a helical gas flow around the burner flame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a conventional hot gas generator is used to heat gas in asphalt production, then the drying process can be maintained, but high levels of pollutants (hydrocarbon compounds and fine particles) are emitted

Engineering Contradiction:
Improvepollutant emissionsVSAvoiddrying efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent applies countercurrent flow where the gas flow direction is oriented opposite to the heat propagation direction. This inversion of the conventional parallel flow arrangement enables more efficient combustion of hydrocarbon components while reducing pollutant emissions, as the coldest gas contacts the hottest combustion zone first, progressively heating up and allowing complete combustion before exiting

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a flow deflection unit with swirl generators that create periodic rotational motion in the gas flow. This periodic swirling action enhances mixing between gas and combustion products, improving combustion efficiency and reducing unburned hydrocarbon emissions while maintaining drying productivity

Inventive Principle:
Principle #19Periodic action

2Device complexity

If the gas flow moves directly from inlet to outlet in a linear path, then the system structure is simple, but combustion efficiency is reduced and pollutant content increases

Engineering Contradiction:
Improveflow path structureVSAvoidpollutant content
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent employs curved flow paths through swirl generators and deflection elements that create helical and rotational gas flow patterns. These curved paths replace simple linear flow, extending the residence time of gas in the combustion zone and improving mixing, which significantly reduces pollutant content despite increased structural complexity

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent adds rotational and radial dimensions to the gas flow by introducing swirl generators that create three-dimensional helical flow patterns. This dimensional transformation from simple linear (1D) flow to complex three-dimensional (3D) flow enhances combustion efficiency and pollutant reduction while requiring more sophisticated flow path design

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

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 significantly reduces pollutant emissions, achieving efficient combustion of carbon compounds and improving the overall energy balance in the system, allowing for up to 90% recycling of asphalt material while minimizing contamination and the need for system cleaning.

Implementation Method 1

the hot gas generator is operated in a countercurrent process. For this purpose, a heat propagation direction is oriented opposite a gas flow direction

Methodology Applied
Scientific EffectCountercurrent heat exchange: Convection

Implementation Method 2

The flow deflection unit enables flow around a burner flame... The flow deflection unit creates a helical gas flow with respect to the longitudinal axis

Methodology Applied
Scientific EffectHelical flow: Vortex Ring

Implementation Method 3

the combustion of hydrocarbon components is particularly efficient... The pollutant content in the hot gas leaving the hot gas generator is reduced. In particular, the proportion of carbon monoxide (CO) and/or carbon dioxide (CO2)... is reduced

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3327349B1Hot gas generator for heating gas and system for asphalt manufacture with such a hot gas generator
Publication Date: 2024.10.23 BENNINGHOVEN ZWEIGNEIDERLASSUNG DER WIRTGEN MINERAL TECH GMBH
  • EP3327349B1 patent drawingFigure 1
  • EP3327349B1 patent drawingFigure 2
  • EP3327349B1 patent drawingFigure 3

AI summary

A hot gas generator (3) for heating gas comprises a housing (55) that is cylindrical with respect to a longitudinal axis (33) and has a heat supply opening (42) for supplying heat along a heat propagation direction (40), a gas inflow opening (35) for supply of gas, a gas discharge opening (36) for discharging the heated gas, a gas flow direction (7) oriented from the gas inflow opening (35) to the gas discharge opening (36), which is oriented opposite to the heat propagation direction (40), a Flow deflection unit (45) for deflecting the gas flow in the housing.