Artillery Propellant Charge System with Surface Plasticizer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing propellant charge systems for 105 mm howitzers experience significant variations in muzzle velocity and peak gas pressure due to temperature fluctuations, leading to reduced accuracy and increased safety risks, especially in hot climates, as they are influenced by the use of explosive oils and plasticizers like dinitrotoluene and dibutyl phthalate, which are also environmentally hazardous.

Innovation Solution

A propellant charge system comprising two types of powders, one with a diffused second inert plasticizer in surface zones and the other without, optimized to maintain consistent internal ballistic characteristics across a wide temperature range, using nitrocellulose and nitramine compounds like RDX, with specific surface treatments to enhance thermal efficiency and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional propellant powders with plasticizers like dinitrotoluene and dibutyl phthalate are used, then the propellant achieves adequate combustion performance, but the system experiences significant variations in muzzle velocity and peak gas pressure due to temperature fluctuations and environmental hazards arise

Engineering Contradiction:
Improveconsistency of muzzle velocity and peak gas pressureVSAvoidtemperature sensitivity and environmental hazard
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the propellant powder. Specifically, it replaces traditional plasticizers (dinitrotoluene and dibutyl phthalate) with alternative plasticizers that have different thermal and chemical properties. This substitution changes the combustion characteristics and temperature sensitivity of the propellant, thereby reducing variations in muzzle velocity and peak gas pressure across different temperature conditions while eliminating environmental hazards associated with toxic substances

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by creating a multi-component propellant formulation that combines nitrocellulose, nitramine compounds, and alternative plasticizers in specific proportions. This composite structure leverages the complementary properties of each component: nitrocellulose provides base combustion, nitramine compounds enhance energy density and temperature stability, and alternative plasticizers ensure flexibility and chemical stability. The synergistic interaction among these components achieves consistent ballistic performance across wide temperature ranges while eliminating toxic substances

Inventive Principle:
Principle #40Composite materials

2Force

If propellant powders are used to achieve high destructive effect, then the ammunition delivers maximum destruction, but the system exceeds gas pressure limits under certain temperature conditions

Engineering Contradiction:
Improvedestructive effectVSAvoidpeak gas pressure
Core Design Contradiction:
ForceVSStress or pressure

Solution Approach 1:

The patent applies parameter changes by adjusting the chemical composition parameters of the propellant to optimize the balance between energy release and pressure generation. By selecting alternative plasticizers with specific molecular weights and chemical structures, the combustion rate and gas generation characteristics are modified. This ensures that the propellant delivers sufficient destructive effect through adequate muzzle velocity while maintaining peak gas pressure within safe limits across the operational temperature range

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback through the careful selection and optimization of propellant components based on their thermal and combustion characteristics. The alternative plasticizers are chosen specifically for their ability to modulate the combustion rate in response to temperature changes, creating a self-regulating effect where the propellant automatically adjusts its energy release rate to prevent excessive pressure buildup while maintaining adequate destructive effect

Inventive Principle:
Principle #23Feedback

3Ease of manufacture

If toxic substances like dinitrotoluene and dibutyl phthalate are used in propellants, then adequate plasticization and combustion performance are achieved, but environmental hazards and chemical instability increase

Engineering Contradiction:
Improvecombustion performanceVSAvoidtoxicity and environmental hazard
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies the extraction principle by completely removing toxic substances (dinitrotoluene and dibutyl phthalate) from the propellant formulation. The alternative plasticizers selected for this invention have superior environmental profiles and chemical stability while maintaining or improving combustion performance. This extraction of harmful components eliminates environmental hazards and chemical instability issues associated with traditional plasticizers

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of traditional plasticizers into benefit by selecting alternative substances that not only eliminate toxicity but also provide enhanced chemical stability and improved combustion characteristics. The alternative plasticizers offer better thermal stability, reduced environmental impact, and improved long-term storage stability, thereby transforming the problem of toxic substance usage into an opportunity for overall propellant performance improvement

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

The system achieves minimal variance in muzzle velocity and peak gas pressure across temperatures from -46°C to 63°C, increasing hit probability and operational flexibility while avoiding toxic substances, with high thermal conversion rates and chemical stability, and does not exceed the gas pressure limit, allowing for extended operational temperature ranges.

Implementation Method 1

a propellant charge system for firing artillery shells, in particular for 105 mm howitzers, based on a combination of two different powder types

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

with diffused inert plasticizer in near-surface zones

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3317606B1Propellant charge system for artillery shells
Publication Date: 2020.06.10 NITROCHEM WIMMIS
  • EP3317606B1 patent drawingFigure 1~2

AI summary

The present application relates to a propellant charge system for firing artillery shells comprising at least two partial charges. The partial charges each have one type of powder, which comprises nitrocellulose, at least one crystalline energy carrier and at least a first inert plasticiser. At least one partial charge has a first type of powder and the at least one further partial charge has a second type of powder. The second type of powder has between 2 and 10 percent by weight of a second inert plasticiser in the region of zones near the surface, to a maximum depth of penetration of 400 micrometres, while the first type of powder has no second inert plasticiser in zones near the surface.