Expandable Plug Borehole Charging Hose

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Solution Overview

Problem

Existing methods for explosive charging in mining and tunnelling holes face issues such as blockages in hoses due to softened ANFO, premature sensitization of emulsion explosives, and difficulty in maintaining materials at desired depths within the hole, leading to safety hazards and inefficiencies.

Innovation Solution

A charging hose and plug arrangement with separate conduits for explosive base materials and additives, allowing for late-stage mixing and the use of expandable plugs with adjustable diameters to create mechanical blockages at specific depths, reducing the risk of blockages and explosions while ensuring precise placement of charging materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additives are dosed directly to ANFO tank or right after tank, then mixing makes ANFO sticky to stay better in vertical up holes and reduces dusting, but blockages occur in ANFO tank and hoses due to softened half-melted ANFO prill structure

Engineering Contradiction:
Improvecharging reliabilityVSAvoidcharging speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent divides the charging system into separate conduits: one for ANFO base material and another for additives. This segmentation prevents premature mixing that causes blockages, while allowing controlled mixing only at the desired location, thus maintaining charging reliability without sacrificing productivity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary actions by separately transporting ANFO and additives through dedicated conduits to the charging location. The mixing action is delayed until the materials reach the borehole, preventing premature softening and blockages while ensuring proper mixing occurs when needed

Inventive Principle:
Principle #10Preliminary action

2Reliability

If gassing solution is mixed in early stage in process unit, then emulsion matrix is sensitized to emulsion explosive, but great danger occurs because detonator and primer are pushed to bore hole by same charging hose which is full of explosive material

Engineering Contradiction:
Improveexplosive charging reliabilityVSAvoidexplosion danger
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the charging system into separate conduits for explosive material and gassing solution. This ensures that sensitization occurs only after the explosive material has been delivered to the borehole, eliminating the danger of having sensitized explosive in the charging hose during detonator and primer insertion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary delivery of explosive material through dedicated conduits before introducing gassing solution. This timing sequence ensures that sensitization happens only after the charging hose is clear of detonators and primers, eliminating explosion hazards while maintaining reliable explosive charging

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If mechanical blockages are inserted into hole before introducing charging materials, then materials can be contained at desired depth, but process becomes very cumbersome and slow requiring separate insertion steps

Engineering Contradiction:
Improvematerial placement precisionVSAvoidcharging efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges the blockage insertion function with the charging material delivery by using the same conduit system. The expandable plug is introduced through the charging hose along with the explosive materials, eliminating separate insertion steps while maintaining precise placement capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses an expandable plug that changes its diameter dynamically - small diameter during insertion for easy delivery, then expanded to large diameter at the desired depth to create effective blockage. This dynamic transformation enables precise placement without cumbersome manual insertion operations

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If mechanical blockages are pushed by long sticks into hole, then blockage can be positioned at certain depth, but blockage tangles easily in surface of hole and pushing stick might get broken making recovery impossible

Engineering Contradiction:
Improveblockage depth positioningVSAvoidoperation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent uses pneumatic pressure through the charging hose to push the expandable plug into the borehole, eliminating the need for long mechanical pushing sticks. This pneumatic method prevents tangling and breaking issues while maintaining precise depth positioning capability through controlled pressure application

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 solution significantly reduces blockages and safety risks by mixing additives and explosives only at the end of the hose, delaying sensitization of emulsion explosives, and allowing for precise placement of plugs and explosives, thereby enhancing the efficiency and safety of the charging process.

Implementation Method 1

the plug has a diameter, the size of which is configured to be manipulated after or during introducing into said bore hole at a certain depth so that after said introducing the diameter of the plug is larger than before said introducing

Methodology Applied
Scientific EffectExpansion:

Data Source

PatentEP3129744B1Method and arrangement for providing explosive charging into a bore hole
Publication Date: 2023.03.22 NORMET
  • EP3129744B1 patent drawingFigure 1
  • EP3129744B1 patent drawingFigure 2A~3B

AI summary

An arrangement (100) for providing explosive charging (107) and a plug into a bore hole (102), wherein a hose comprising at least one first conduit (103) is introduced into said bore hole. Also explosive material is introduced to an outlet of said first conduit and thereby into said bore hole. In addition a plug (114) is introduced into said bore hole by the help of said hose (101). The plug has a diameter, the size of which is configured to be manipulated after or during introducing into said bore hole at a certain depth so that after said introducing the diameter of the plug is larger than before said introducing and so that the surface of the plug after manipulating the size of diameter essentially make a physical contact with the bore hole surface. The plug is introduced by said hose in a releasable manner (115) so that after or during the manipulation of the plug diameter size the plug is configured to be released from the hose and to stay in said bore hole essentially at said certain depth.