Helical Duct Head for Jet Grouting

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Solution Overview

Problem

Conventional jet grouting monitors experience high friction losses and reduced column diameter due to turbulent fluid flow, leading to increased power consumption and inefficiencies in soil consolidation.

Innovation Solution

The monitor features a helical duct geometry with a constant radius and linearly varying cross-sectional area, minimizing head losses by guiding the fluid in a continuous helical path with a linearly decreasing pitch and inclination, reducing turbulence and friction losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional radial nozzles with orthogonal stream deviation are used, then the monitor structure is simple, but head losses increase due to turbulence and friction

Engineering Contradiction:
Improvehead lossesVSAvoidmonitor structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies curved ducts with gradual changes in direction instead of orthogonal radial holes. The stream follows a curved path from the central duct to the peripheral nozzles, avoiding sudden deviations that cause turbulence. This curvature principle reduces concentrated head losses while maintaining structural feasibility.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent employs dynamically optimized duct geometry with variable cross-sectional area and curvature radius along the flow path. The duct dimensions are adjusted to maintain optimal flow conditions, balancing friction losses against structural constraints. This dynamic design allows the system to adapt to changing flow conditions along the path.

Inventive Principle:
Principle #15Dynamics

2Area of stationary object

If duct diameter is reduced to limit external dimensions, then the monitor size is compact, but friction losses increase due to high velocity

Engineering Contradiction:
Improvemonitor external dimensionsVSAvoidfriction losses
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The patent applies different duct cross-sectional areas at different locations along the flow path. The duct is larger where friction losses would be high and tapers to a smaller diameter near the nozzle outlet. This local variation in geometry optimizes the balance between compact overall dimensions and minimized friction losses in critical regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes geometric parameters (cross-sectional area, curvature radius) along the flow path to optimize performance. The duct transitions from a larger diameter at the inlet to a smaller diameter at the outlet, with the curvature radius also varying to maintain smooth flow. These parameter changes reduce friction losses while keeping the monitor compact.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If multi-helical geometry is used to guide stream, then head losses are reduced, but the structure becomes more complex and difficult to manufacture

Engineering Contradiction:
Improvehead lossesVSAvoidmonitor assembly
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent divides the monitor into separate functional components: a central duct, peripheral ducts with curved geometry, and modular nozzle assemblies. This segmentation allows each component to be manufactured and assembled independently, simplifying the overall manufacturing process while maintaining the beneficial curved flow path geometry.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses curved ducts that guide the stream in a smooth arc from the central duct to the peripheral nozzles. This curvature eliminates sudden directional changes and reduces turbulence-induced head losses. The curved geometry is implemented in a way that is manufacturable using standard fabrication techniques.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This design achieves lower head losses and higher energy jets at the nozzles, resulting in a more effective soil consolidation process with a larger column diameter using the same power consumption.

Implementation Method 1

a helical duct (13) configured to convey the fluid mixture from the inlet (16) to the inlet of the nozzle (11) along a helical path

Methodology Applied
Scientific EffectHelical flow: Helix

Implementation Method 2

minimizing head losses by guiding the fluid in a continuous helical path with a linearly decreasing pitch and inclination, reducing turbulence and friction losses

Methodology Applied
Scientific EffectTurbulence reduction: Turbulence

Implementation Method 3

lower head losses and higher energy jets at the nozzles, resulting in a more effective soil consolidation process

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2407598B1A head for injecting consolidating pressurized fluid mixtures into the ground
Publication Date: 2015.04.01 TREVI
  • EP2407598B1 patent drawingFigure 1~3
  • EP2407598B1 patent drawingFigure 4~5
  • EP2407598B1 patent drawingFigure 6~10C

AI summary

The head (10) includes an outer cylindrical body (12) with at least one upper inlet (16) for fluids, at least one outlet side nozzle (11) and at least one helical duct (13) having a helical central line (m). The duct connects the upper inlet (16) to the nozzle (11) and imparts the fluid flowing through it a helical motion about the longitudinal axis (Z) of the outer body (12) towards the nozzle (11). The helical duct (13) is progressively tapered towards the nozzle (11) and includes a terminal length of the duct which is radiused to the nozzle in a tapered manner, both when viewed in cross-sectional planes (P) parallel to the longitudinal axis (Z) and tangent to the helical central line, as well as when viewed in cross-sectional planes perpendicular to the longitudinal axis (Z).