Ventilation Element for Frozen Reducing Agent Storage Tanks

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Solution Overview

Problem

Existing SCR systems for reducing NOx in internal combustion engine exhausts face challenges with frozen reducing agents, requiring complex heating and ventilation systems to maintain system pressure and prevent ice expansion, leading to increased costs and complexity.

Innovation Solution

A simplified design that vents the air space in the storage tank to the environment through a hose line, using a venting element connected to both the tank and pot-shaped container, allowing pressure equalization and reducing the number of components, with a vent line made of reducing agent-resistant materials, and optionally using separate vents for the tank and pot.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex heating and ventilation system is used to prevent frozen reducing agent and maintain system pressure, then system reliability is improved, but device complexity and production costs increase

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the ventilation function from the complex heating and ventilation system by providing a dedicated vent line that directly connects the air space above the reducing agent to the environment. This separate ventilation path allows air to escape independently without requiring complex pressure regulation mechanisms, thereby maintaining system reliability while reducing overall system complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the pressure management function by separating the ventilation path from the heating system. The vent line creates an independent air escape route that operates autonomously from the heated suction lance and pump system, allowing each component to perform its specific function without interdependency, thus simplifying the overall device

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple components are used for heating and pressure regulation, then system functionality is improved, but manufacturing and assembly costs increase

Engineering Contradiction:
Improvesystem functionalityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The vent line serves multiple functions: it ventilates the air space above the reducing agent, allows pressure equalization, and prevents ice expansion by enabling air escape. By consolidating these functions into a single simple component rather than using separate heating and pressure regulation devices, the patent reduces manufacturing and assembly costs while maintaining comprehensive system functionality

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The ventilation system operates autonomously without requiring active control or additional energy input. The vent line passively allows air to escape when pressure builds up, and the system self-regulates through the natural pressure differential, eliminating the need for complex pressure sensors, control valves, and associated assembly steps

Inventive Principle:
Principle #25Self-service

3Reliability

If the reducing agent is heated to prevent freezing, then system reliability is improved, but energy consumption increases

Engineering Contradiction:
Improvesystem reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The heated suction lance operates periodically rather than continuously - it is activated only when the pump needs to draw liquid reducing agent from the storage tank. This periodic operation reduces energy consumption compared to continuous heating, while still maintaining system reliability by ensuring the reducing agent is thawed at the moment of withdrawal

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts the heating function from a continuous system-wide heating approach and applies it locally and periodically only to the suction lance when needed. This localized, on-demand heating significantly reduces overall energy consumption while maintaining the reliability of the reducing agent delivery system

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 design simplifies the system, reduces production and assembly costs, enhances robustness, and ensures effective ventilation, maintaining system functionality even at low temperatures by eliminating the need for additional heating elements and complex pressure regulation.

Implementation Method 1

pressure equalization can take place in the environment, taking into account the hose line, both the air space in the pot and the air space above the tank

Methodology Applied
Scientific EffectPressure equalization: Pascal's Law

Implementation Method 2

an electrical heater is built into the storage tank inside a pot that is open at the bottom. Thus, the heat given off by the heater is first used to thaw the contents of the pot

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

The reducing agents commonly used today freeze between -11 ° C and -40 ° C, depending on the antifreeze added

Methodology Applied
Scientific EffectFreezing: Freezing

Implementation Method 4

the solid ice-shaped phase and a liquid phase are established in the storage tank

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2510203B1Ventilation element for a storage tank
Publication Date: 2015.12.23 ROBERT BOSCH GMBH
  • EP2510203B1 patent drawingFigure 1
  • EP2510203B1 patent drawingFigure 2~4
  • EP2510203B1 patent drawingFigure 3

AI summary

The invention relates to a storage tank (10) for receiving a medium (12) that can be frozen, in particular a reducing agent, comprising a ventilation unit (34, 36; 72) and a crucible-shaped container (22) introduced in the storage tank (10). An air chamber (50) in the crucible-shaped container (22) is connected via a ventilation line (60) or an overflow opening (40) to an air chamber (48) of the storage tank (10), which is ventilated via a ventilation unit (34, 36; 72).