Valve-Free Pump Seal Park Position for Freezing Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Devices for supplying liquid additives, such as urea-water solutions, face damage from freezing at low temperatures due to volume expansion, which can be costly to protect against or require energy-intensive evacuation procedures.
Innovation Solution
A method utilizing a valve-free delivery line and a reversible positive-displacement pump with a seal that can be adjusted to a park position to prevent damage from freezing, allowing for evacuation without additional components and energy-efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the device is designed to be protected against freezing damage, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The seal is moved to a park position before freezing occurs, positioning it at the outlet side of the pump where it prevents ice formation from damaging the pump. This preliminary protective action avoids the need for complex heating systems or insulation, resolving the contradiction between reliability and device complexity
Solution Approach 2:
The system uses the pump's own sealing mechanism to protect itself from freezing damage. By repositioning the existing seal to a protective location, the system eliminates the need for separate protection systems, maintaining simplicity while ensuring reliability
2Reliability
If evacuation is performed after stoppage to prevent freezing, then reliability is improved, but energy consumption and operational burden increase
Solution Approach 1:
Instead of evacuating the system after stoppage, the seal is repositioned to a park position before freezing can occur. This preliminary protective measure eliminates the need for energy-consuming evacuation operations while maintaining protection against freezing damage
Solution Approach 2:
The harmful liquid additive is effectively removed from the pump by repositioning the seal to exclude it, preventing freezing within the pump without requiring full system evacuation. This reduces energy consumption compared to complete evacuation while maintaining protective function
3Device complexity
If a valve-free delivery line is used, then device complexity is reduced, but control precision over liquid additive delivery may worsen
Solution Approach 1:
The patent replaces valve-based flow control with a positive-displacement pump mechanism that delivers precise volumes through its pumping action. The pump's displacement geometry inherently controls delivery precision without requiring valves, resolving the contradiction between device complexity and dosing precision
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
The method effectively protects the device from freezing damage while maintaining energy efficiency and reducing the need for complex components, ensuring accurate dosing and delivery of the liquid additive.
Implementation Method 1
a valve-free positive-displacement pump, wherein the positive-displacement pump is designed to deliver the liquid additive from the tank via the intake point and along the delivery line to the supply unit, and wherein the positive-displacement pump has at least one seal of the delivery line, which at least one seal can be displaced along the delivery line for the purposes of delivering the liquid additive
Implementation Method 2
The freezing process causes a volume expansion of the aqueous additive. The volume expansion can damage the device for supplying the liquid additive.
Implementation Method 3
The freezing process causes a volume expansion of the aqueous additive
Data Source
AI summary
A method for operating a device for providing a liquid additive having at least one suction point for removing liquid additive from a tank, a valve-free conveying line extending from the suction point to a supply unit, and a valve-free displacement pump, the displacement pump being configured to convey the liquid additive from the tank via the suction point along the conveying line to the supply unit, the displacement unit having at least one seal of the conveying line, displaceable along the conveying line for conveying the liquid additive, includes: a) detecting a stoppage of operation of the device; b) establishing a position of the seal within the positive-displacement pump; and c) changing the position of the seal if the position of the seal does not correspond to a provided park position of the seal.