Drilling Turret Torque Correction for Specific Energy
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Solution Overview
Problem
Existing methods for installing foundation piles using CAP and CSP technologies face challenges in accurately determining the specific energy of drilling due to internal interactions between the propeller and tube, which alter the measured values, and the need to account for distributed frictions over large contact areas, making it difficult to evaluate ground resistance variations during excavation.
Innovation Solution
A method and apparatus that utilize sensors to measure drilling parameters such as torque, thrust, and speed, and apply a corrective factor to account for internal interactions by simulating the drilling process with 'loadless' measurements to separate energy contributions from internal and external frictions, allowing for real-time analysis of ground characteristics and energy expenditure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If drilling parameters are measured during CAP/CSP excavation, then real-time ground characteristic analysis becomes possible, but internal interactions between propeller and tube alter the measured values making specific energy determination inaccurate
Solution Approach 1:
The patent extracts and isolates the internal friction component from the total measured energy consumption. By separately measuring or calculating the energy lost to internal friction between the propeller and tube, this harmful factor is removed from the specific energy calculation, leaving only the energy actually spent on ground removal.
Solution Approach 2:
The patent introduces an intermediary calculation or measurement step that accounts for the internal friction interactions. This intermediary factor serves as a correction term that mediates between the raw measured parameters and the accurate specific energy value, allowing the harmful internal friction to be quantified and compensated for.
2Strength
If the covering tube is used to stabilize borehole walls and enable hard ground advancement, then drilling capability is improved, but distributed frictions over large contact areas make energy evaluation difficult
Solution Approach 1:
The patent segments the total friction into distinct components: internal friction (propeller-ground-tube interactions) and external friction (tube-borehole wall interactions). By dividing the complex distributed friction into manageable segments, each can be measured or calculated separately and incorporated into the specific energy determination.
Solution Approach 2:
The patent applies different measurement or calculation approaches to different locations and components of the drilling system. Local measurements of torque, thrust, and rotation speeds are taken at specific points, and local friction characteristics are determined for the propeller-tube interface versus the tube-borehole interface, allowing accurate energy evaluation despite the distributed nature of the frictions.
3Productivity
If propeller and tube rotate in opposite directions to enable ground discharge, then excavation efficiency is improved, but internal friction interactions increase altering drilling parameters
Solution Approach 1:
The patent converts the harmful internal friction effect into a useful measurement opportunity. By recognizing that the opposite rotation creates measurable internal friction, the patent uses this friction as an indicator to calculate and compensate for its effect, ultimately improving the accuracy of specific energy determination while maintaining the beneficial opposite rotation for ground discharge.
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 accurate determination of the actual energy required for drilling by isolating internal friction contributions, providing real-time data on ground resistance and characteristics, which improves excavation efficiency and informs design modifications for better performance and productivity.
Implementation Method 1
The rotations must advantageously occur in opposite directions to allow the ground to climb up along the propeller because of the inner friction between the material and the tube wall, to be then discharged in the upper part of the covering tube.
Data Source
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AI summary
An apparatus for drilling the ground, in particular for the installation of foundation piles, comprises a drilling turret (2) with a vertical guiding antenna (3), a rotary head for driving drilling batteries comprising a continuous ground drilling rotary propeller (5) housed inside at least one covering tube (7), first inner drive means adapted to drive said propeller (5), and second external drive means connected to the tube (7) and allowing movement thereof, a driving cab (8) for an operator, which includes all the manipulators for operating the machine and the systems for displaying measured parameters. The apparatus further comprises a system for controlling the excavation parameters, which is enabled to receive information from the drilling parameter control sensors.