Freeze Pipe Sleeve Structure for Easier Ground Extraction
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Solution Overview
Problem
Existing ground freezing methods using freeze pipes face difficulties in removing the pipes from the soil after icing, due to the pipes becoming frozen to the ground and the limited tensile force that can be applied, which impedes further construction processes.
Innovation Solution
A ground freezing device with a hollow body around the freeze pipe, made of a flexible or inflexible material with a low coefficient of friction, such as polytetrafluoroethylene, that prevents direct contact between the freeze pipe and the ground, allowing for easier removal by heating the contact medium to a liquid or gaseous state before extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If freeze pipes are used for ground freezing, then effective cooling and freezing of the soil is achieved, but the pipes become frozen to the ground and are difficult to remove
Solution Approach 1:
A hollow body is introduced as an intermediary element between the freeze pipe and the surrounding soil. This hollow body prevents direct contact and freezing adhesion between the pipe and ground, allowing the pipe to be removed after the freezing task is completed while the hollow body remains in the ground.
Solution Approach 2:
The system is segmented into three distinct components: the freeze pipe (for cooling), the hollow body (as a removable intermediary), and the surrounding soil. This segmentation allows the freeze pipe to be separated from the ground system after use, solving the removal problem.
2Ease of operation
If force is applied to pull the freeze pipe from frozen ground, then pipe removal is attempted, but the tensile force is limited by material strength and vacuum forces
Solution Approach 1:
The hollow body acts as a mediator that eliminates the need for high tensile forces. By preventing direct freezing adhesion between the pipe and ground, the pipe can be removed with minimal force, avoiding material strength limitations and vacuum forces.
3Reliability
If freeze pipes remain in the soil after icing, then the freezing function is maintained, but construction machinery cannot pass through the pipes
Solution Approach 1:
The freeze pipe is extracted from the ground system after completing its freezing function. The hollow body remains in the ground to maintain ground support, while the freeze pipe is removed to allow construction machinery to pass through, thus resolving the conflict between ground support and construction progress.
Solution Approach 2:
The freeze pipe is discarded (removed) after its useful function is completed, while the hollow body is recovered and left in the ground to continue providing ground support. This allows the system to transition from the freezing phase to the construction phase.
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
Facilitates the removal of freeze pipes from the ground without damaging soil working machines, ensuring efficient continuation of construction processes by preventing the pipes from freezing to the soil and reducing the force required for extraction.
Implementation Method 1
Liquid nitrogen passes downwardly through an inner pipe and into the freeze pipe, evaporates, and while rising in the annular space imparts its cooling energy to the surrounding soil
Implementation Method 2
Extracting the heat cools and freezes the water in the surrounding soil
Implementation Method 3
The hollow body can be made out of a flexible or inflexible material... The hollow body is preferably at least partially or even completely made out of a polymer material. A polytetrafluoroethylene (PTFE) has here proven effective. The advantage to polytetrafluoroethylene (PTFE) is that it has a very low coefficient of friction
Implementation Method 4
allowing for easier removal by heating the contact medium to a liquid or gaseous state before extraction
Data Source
AI summary
A method and a device for freezing the ground are provided with a freeze pipe closed on one front side, and an inner pipe extending into the freeze pipe for supplying a cooling agent, and wherein a hollow body is provided, whose inner diameter is larger than the outer diameter of the freeze pipe.