Drilling and Grouting Device Crossover Flow Path
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Solution Overview
Problem
Reverse Circulation rotary drilling methods are inadequate for grouting operations, particularly when dealing with high viscosity grout, as the annular space between the drill rods is prone to plugging, and the drill bit can be damaged by grout injection, requiring time-consuming device removal for separate injection systems.
Innovation Solution
A drilling and grouting device with a hollow elongate outer and inner rod configuration, featuring a crossover part that connects central and outer flow paths, allowing for simultaneous drilling and grouting without removing the device, with drilling fluid deviated towards the drill bit to manage cuttings and grout flow efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If grout is injected through the annular space between outer and inner rod, then grouting can be performed, but the grout may plug the device due to high viscosity and large wetted perimeter
Solution Approach 1:
The invention extracts the grout injection function from the annular space and relocates it to the inner rod's central flow path. The crossover part directs grout from the inner rod through the drill bit's central flow path, bypassing the annular space entirely. This extraction eliminates the plugging risk associated with the annular space's large wetted perimeter while preserving grouting capability.
Solution Approach 2:
The crossover part acts as an intermediary component that mediates between the inner rod's central flow path and the drill bit's central flow path. It connects these two flow paths, enabling grout to travel from the inner rod through the drill bit without contacting the annular space, thus preventing plugging while maintaining grout injection functionality.
2Adaptability or versatility
If grout is injected through the inner rod, then grouting can be performed, but the drill bit can be damaged and free flow is prevented
Solution Approach 1:
The invention segments the flow paths into distinct channels: the inner rod provides a central flow path for grout, the crossover part provides a transition, and the drill bit's central flow path provides a protected passage. This segmentation allows grout to flow through the drill bit's central channel without contacting the drill bit's cutting elements, preventing damage while enabling grouting.
Solution Approach 2:
The invention utilizes the central axial dimension of the drill bit rather than its radial annular dimension. By routing grout through the drill bit's central flow path (axial dimension) rather than around it (radial dimension), the system enables grout injection without the grout contacting the drill bit's outer cutting surfaces, thus preventing damage.
3Productivity
If inner rod and drill bit are removed to allow free grout flow, then grouting efficiency improves, but time is lost and additional equipment is needed
Solution Approach 1:
The invention makes the drill string universal by enabling it to perform both drilling and grouting functions without removal. The inner rod and crossover part are designed to facilitate grout flow through the existing drill string structure, allowing the same equipment to efficiently perform both drilling and grouting operations sequentially without time-consuming removal and replacement.
4Productivity
If drilling fluid is passed through the annular space, then drilling can be performed, but the flow path is inefficient for high viscosity grout
Solution Approach 1:
The invention creates a dynamic flow path system where the crossover part can redirect flow between different channels. During drilling, fluid flows through the annular space; during grouting, the same system redirects grout through the inner rod's central flow path and drill bit's central flow path. This dynamic adaptability allows efficient drilling with low-viscosity fluid while enabling effective grouting with high-viscosity material through a different flow path.
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
Enables efficient and quick drilling and grouting by preventing plugging, increasing production rates, and providing a 'double-protection' system for cuttings and grout, suitable for various drilling orientations and environmentally sensitive areas.
Implementation Method 1
a crossover part interposed between said inner rod and said drill bit along said central axis, said crossover part being configured to connect the first central flow path with a second outer flow path surrounding the drill bit to form a main path and to connect said first outer flow path with said second central flow path to form a secondary path
Data Source
AI summary
A drilling and grouting device comprises a drill string including a hollow elongate outer rod having a central axis and a hollow elongate inner rod located coaxially within said outer rod, wherein a first outer flow path is defined between said inner and outer rod, and a first central flow path is defined inside said inner rod, a drill bit aligned with said inner rod along said central axis and including a second central flow path, and a crossover part interposed between said inner rod and said drill bit along said central axis, which is configured to connect the first central flow path with a second outer flow path surrounding the drill bit to form a main path and to connect said first outer flow path with said second central flow path to form a secondary path. Also disclosed are systems and methods that include and use the device.