Mandrel Elevation for Large Diameter Wound-Fiber Tank Construction

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Solution Overview

Problem

Conventional methods for constructing large diameter wound-fiber reinforced tanks face engineering and safety challenges due to the weight and size limitations of elevated tank wall segments, making it impractical to build tanks with diameters greater than 60 feet or heights greater than 30 feet.

Innovation Solution

A mandrel system with a center pivot and radial trusses is used, allowing the mandrel to be raised instead of the tank walls, enabling the construction of large diameter tanks by rotating and elevating the mandrel to form successive cylindrical segments, which are then integrally joined, thus avoiding the weight and safety issues associated with elevating tank wall segments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If tank wall segments are elevated to add additional segments, then tank height can be increased, but weight and safety limitations prevent construction of tanks taller than 30 feet

Engineering Contradiction:

Improvetank heightVSAvoidtank wall segment weight

Core Design Contradiction:

Length of stationary objectVSWeight of moving object

Solution Approach 1:

Instead of elevating the tank wall segments as in conventional methods, the mandrel is elevated to a second position above the first tank segment. The mandrel is then used to form a second cylindrical wall segment that is integrally joined to the upper section. This inversion of the elevation target (mandrel vs. tank wall) resolves the weight and safety limitations.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The tank construction is divided into multiple cylindrical segments formed on the mandrel at different positions. Each segment is formed separately and then integrally joined to create the complete tank structure, allowing the mandrel to be repositioned between segments without handling heavy tank sections.

Inventive Principle:

Principle #1Segmentation

2Area of stationary object

If tank diameter exceeds 60 feet, then larger storage capacity is achieved, but engineering difficulties and safety concerns make it impractical

Engineering Contradiction:

Improvetank cross-sectional areaVSAvoidconstruction safety

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The mandrel is elevated rather than the tank segments, which eliminates the need to handle and position extremely heavy large-diameter tank sections. This inversion makes large diameter construction (greater than 60 feet) safe and practical.

Inventive Principle:

Principle #13The other way round (Inversion)

3Weight of moving object

If mandrel is raised instead of tank walls, then weight and safety limitations are avoided, but mandrel positioning and repositioning complexity increases

Engineering Contradiction:

Improvemoved component weightVSAvoidmandrel positioning system

Core Design Contradiction:

Weight of moving objectVSDevice complexity

Solution Approach 1:

A positioning system acts as an intermediary between the mandrel and the ground, providing controlled elevation and movement of the mandrel. This mediator handles the complexity of positioning, keeping the mandrel lightweight while achieving the desired construction capabilities.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7481899B2Apparatus and method for making large diameter wound-fiber reinforced tanks

Publication Date: 2009.01.27 BOYD JOHN W

AI summary

A process of constructing a large diameter tank is provided. The process includes the step of providing a tank wall mandrel that has at least one drive wheel and at least one curved panel. Glass fibers are applied from a vertical winder to the curved panel in order to form a segment of a tank wall shell. Additional glass fibers are also applied to the curved panel at a location above the segment of the tank wall shell in order to form a unitary tank shell.