Nested Anti-Erosion Device for Shell-and-Tube Inlet Stability

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Solution Overview

Problem

Existing anti-erosion devices for shell-and-tube equipment, such as ferrules or sleeves, face challenges in maintaining position during high-velocity erosive fluid flows, experiencing misalignment, thermal issues, and difficult maintenance, particularly in vertical setups and when installed at the outlet end.

Innovation Solution

An anti-erosion device comprising a first outer tubular element connected to the inlet tube-sheet and a second inner tubular element inserted into the tubes, with mechanical or hydraulic expansion to secure the inner element within the outer one, covering the internal surface and extending beyond the tube-to-tube-sheet joint, reducing fluid impingement and turbulence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If ferrules or sleeves are installed in inlet tube-sheet bores to protect against erosion, then erosion resistance is improved, but positioning stability deteriorates under high-velocity fluid flow

Engineering Contradiction:

Improveerosion resistanceVSAvoidpositioning stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The invention employs a nested structure where an inner tubular element is inserted within an outer tubular element. The inner element provides erosion protection while the outer element offers structural support and positioning stability. This nested configuration allows each element to fulfill its specific function independently, resolving the contradiction between erosion resistance and positioning stability.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The anti-erosion device is divided into separate modular components (inner tubular element and outer tubular element) that can be independently installed, positioned, and maintained. This segmentation allows the inner element to be optimized for erosion protection while the outer element is optimized for structural stability, eliminating the trade-off present in single-integrated designs.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If ferrules are embedded into refractory lining to secure positioning, then positioning stability is improved, but thermal issues and manufacturing complexity worsen

Engineering Contradiction:

Improvepositioning stabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention extracts the anti-erosion function from the refractory lining system by providing a separate, self-contained tubular structure. This eliminates the need to embed ferrules into refractory material, thereby reducing manufacturing complexity while maintaining positioning stability through the tubular structure's own design features.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The outer tubular element acts as an intermediary structure that provides positioning stability without requiring integration with the refractory lining. It mediates between the need for secure positioning and the desire to avoid complex manufacturing procedures by offering a standalone solution.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If sleeves are expanded against tubes to secure positioning, then positioning stability is improved, but risk of tube damage during installation worsens

Engineering Contradiction:

Improvepositioning stabilityVSAvoidtube integrity

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The outer tubular element serves as a protective cushion between the expansion mechanism and the actual exchange tube. By providing this intermediate layer, the design prevents direct contact and potential damage to the tube during the expansion process, while still allowing secure positioning of the anti-erosion device.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The outer tubular element functions as an intermediary that absorbs the mechanical stresses of installation and expansion. It protects the delicate exchange tube from direct exposure to expansion forces, thereby maintaining tube integrity while achieving secure positioning of the inner erosion-resistant element.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If ferrules extend beyond tube-sheet to provide erosion protection, then erosion resistance is improved, but maintenance difficulty worsens

Engineering Contradiction:

Improveerosion resistanceVSAvoidmaintenance ease

Core Design Contradiction:

Object-affected harmful factorsVSEase of repair

Solution Approach 1:

The modular segmented design with distinct inner and outer elements allows the inner erosion-resistant element to be independently accessed and replaced. The segmentation enables maintenance personnel to remove and replace only the worn inner element without disturbing the outer structural element, significantly improving maintenance ease.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner tubular element is designed as a separate, extractable component that can be removed from the outer tubular element for maintenance. This extraction capability allows easy replacement of the erosion-prone inner element while leaving the outer structural element in place, resolving the contradiction between erosion protection and maintenance ease.

Inventive Principle:

Principle #2Taking out (Extraction)

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 device effectively minimizes erosion and overheating, maintains robustness for severe conditions, and facilitates easy maintenance by avoiding damage during installation and replacement, while ensuring secure positioning and reduced turbulence.

Implementation Method 1

The inner tubular element is joined to the outer tubular element by means of mechanical or hydraulic expansion of at least a first tubular portion of the inner tubular element against the internal surface of the outer tubular element

Methodology Applied

Scientific EffectMechanical expansion:

Implementation Method 2

Methodology Applied

Scientific EffectHydraulic expansion:

Data Source

PatentUS11466942B2Anti-erosion device for a shell-and-tube equipment

Publication Date: 2022.10.11 ALFA LAVAL OLMI SPA

AI summary

Shell-and-tube equipment includes a tube bundle, an inlet tube-sheet, and an anti-erosion device including an outer tubular element and an inner tubular element. A first tubular end of the outer tubular element is connected the inlet tube-sheet, whereas a second free tubular end of the outer tubular element extends in an inlet channel. The inner tubular element is inserted into the outer tubular element, so as to substantially cover the entire internal surface of the outer tubular element, and into at least a portion of the corresponding tube to a point beyond the joint or the second side of the inlet tube-sheet whichever is further from the outer tubular element. The inner tubular element is joined to the outer tubular element by means of mechanical or hydraulic expansion of at least a first tubular portion of the inner tubular element against the internal surface of the outer tubular element.