Hydrocarbon Dosing Valve Layout to Prevent Reverse Flow

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Solution Overview

Problem

Existing hydrocarbon dosing systems for diesel engines suffer from reverse flow of fluids, increased resistance, and malfunction due to the use of additional components like non-return valves, check valves, and pressure relief valves, leading to increased weight, cost, and complexity.

Innovation Solution

A hydrocarbon dosing system with intrinsic non-return and pressure relief valve mechanisms, utilizing solenoid valves and a 3/2 solenoid valve configuration to control fluid flow, minimizing additional components and ensuring low resistance and reduced malfunction possibilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydrocarbon dosing is performed using conventional liquid handling equipment, then the dosing capacity is limited by the equipment's precision and speed, but the system complexity and cost increase when attempting to improve precision and speed

Engineering Contradiction:
Improvedosing capacityVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system divides the dosing task into separate stages: a rough dosing stage using a first liquid handling device and a fine-tuning stage using a second liquid handling device. This segmentation allows each device to be optimized for its specific function, achieving high overall precision and capacity without requiring a single complex device to perform all functions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs multiple liquid handling devices that can each perform both rough and fine dosing operations. The first device handles large volumes with lower precision requirements, while the second device handles small volume adjustments with high precision. This multi-functional approach allows flexible allocation of dosing tasks across devices based on their capabilities

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

2Measurement precision

If conventional liquid handling equipment is used for hydrocarbon dosing, then the dosing precision is limited by equipment capabilities, but increasing precision reduces the dosing speed and capacity

Engineering Contradiction:
Improvedosing precisionVSAvoiddosing speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The dosing process is segmented into rough dosing (lower precision, higher speed) and fine-tuning (high precision, lower speed) stages. The first liquid handling device performs rapid rough dosing to deliver the majority of the required volume, while the second device performs slower but more precise fine-tuning to achieve the exact target dosage

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs excessive dosing by the first device (delivering slightly more than the target volume) followed by precise removal of the excess by the second device. This approach allows the faster first device to operate at higher capacity while the slower second device corrects the dosage to the exact precision required

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3673159B1Hydrocarbon dosing system
Publication Date: 2026.05.06 ROTEX AUTOMATION LTD
  • EP3673159B1 patent drawingFigure 1A
  • EP3673159B1 patent drawingFigure 1B
  • EP3673159B1 patent drawingFigure 1C~1D

AI summary

The present disclosure relates to a hydrocarbon dosing system to control dosing of diesel fuel into an exhaust upstream of a vehicle's oxidation catalyst (VOC). The system 100 includes separate inlets (102,104) to allow inflow of a first fluid and the second fluid into the system, and an outlet 116. The first fluid configured to facilitate purging of the second fluid into the VOC through the outlet 116. The system 100 incorporates multiple valves (106, 108, 112) and pressure sensor 114 to control dosing and purging of the fluids. The system 100 provides an intrinsic non-return valve mechanism to restrict the flow of the first fluid into a fluid path of the second fluid, and vice versa. The system 100 provides intrinsic pressure relief mechanism for controlled release of pressure from system 100. The system 100 includes additional optional check valves 208 and filter screens 206 for redundancy purposes.