Plastic Tank Dome Opening Reinforcement Ring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Plastic tanks face significant weakening due to large dome openings, which compromises their structural stability under internal pressure and external loads like earth and wind pressure, and existing reinforcement methods are complex, costly, and do not adequately address this issue.

Innovation Solution

A reinforcement ring is positioned inside the dome opening, serving as both a stiffening element and a carrier for a sealing ring, integrated during the manufacturing process without requiring special design measures, and can be made from materials like steel or plastic, providing enhanced stability and sealing without increasing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a large dome opening is provided for access and equipment installation, then the tank's accessibility and functionality are improved, but the tank's structural stability and resistance to internal and external pressure are significantly weakened

Engineering Contradiction:
Improveaccessibility to tank interiorVSAvoidstructural stability at dome opening
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies local quality by providing reinforcement specifically at the dome opening area where it is most needed, rather than uniformly throughout the entire tank. The reinforcement element is localized to the opening edge, strengthening this critical area while leaving the rest of the tank structure unchanged, thus maintaining overall structural integrity without unnecessary material expenditure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The reinforcement solution is segmented into a separate, removable element that can be independently installed at the dome opening. This segmentation allows the reinforcement to be applied only where needed and enables easy installation and removal without affecting the entire tank structure, resolving the contradiction between opening size and structural strength.

Inventive Principle:
Principle #1Segmentation

2Strength

If wall thickness is increased in the dome opening area for reinforcement, then the structural stability is improved, but the manufacturing complexity and material cost are significantly increased

Engineering Contradiction:
Improvestability at dome openingVSAvoidmanufacturing complexity and material expenditure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The reinforcement is provided as a separate, segmented element rather than integrating it into the monolithic tank structure. This segmentation simplifies manufacturing by allowing the reinforcement to be produced independently and then attached to the tank, avoiding the need for complex mold modifications or multi-step forming processes that would increase manufacturing complexity and material cost.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reinforcement element acts as an intermediary component that mediates between the dome opening and the tank wall. Instead of directly modifying the tank wall thickness, this intermediary element provides the necessary reinforcement function, simplifying the manufacturing process while achieving the desired structural stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If existing reinforcement methods are used, then some structural support is provided, but the solutions are complex, expensive, and do not adequately solve the weakening problem

Engineering Contradiction:
Improvestructural support at openingVSAvoidcomplexity and cost of reinforcement
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The reinforcement element is designed as a simple, inexpensive component that can be easily manufactured and replaced if necessary. Rather than using complex, expensive permanent reinforcement structures, this approach uses a straightforward element that provides adequate structural support at minimal cost, directly addressing the inadequacies of existing reinforcement methods.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

Instead of trying to prevent weakening by over-engineering the reinforcement, the patent inverts the approach by accepting the opening's weakening effect and compensating for it with a simple, targeted reinforcement element. This inverted thinking leads to a more cost-effective and simpler solution compared to traditional methods that attempt to eliminate the weakening problem entirely through complex design measures.

Inventive Principle:
Principle #13The other way round (Inversion)

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 reinforcement ring effectively compensates for the weakening caused by the dome opening, maintaining the tank's dimensional stability and functionality while reducing manufacturing costs and maintaining aesthetic appearance, and can be easily integrated into the tank's production process.

Implementation Method 1

The reinforcement ring is preferably positioned and integrated in a force-transmitting manner by crystallization of the plastic after the manufacture of the tank or the tank segment

Methodology Applied
Scientific EffectCrystallization shrinkage: Crystallisation

Data Source

PatentEP2374735B1Tank
Publication Date: 2013.06.12 GRAF PLASTICS A GERMAN CORP
  • EP2374735B1 patent drawingFigure 1
  • EP2374735B1 patent drawingFigure 2
  • EP2374735B1 patent drawingFigure 3

AI summary

The tank has a tank segment comprising a dome opening (11) with a dome-opening edge (6), where the tank is made from plastic. The dome opening is reinforced by a ring insert (R) in an inner side of the opening edge, where the ring insert is made from material e.g. plastic or steel, having higher rigidity than the plastic of the tank. The plastic of the opening edge is shrunk on the ring insert and/or a circulating groove (13) is formed in the inner side of the opening edge, where the ring insert with a part of a cross-section is positioned in the groove in a form-fit manner.