Offshore Air Dehumidification With Recirculation for Salt Filter Protection

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Solution Overview

Problem

Existing dehumidification systems in offshore installations, particularly wind turbines, face inefficiencies and short filter lifetimes due to the difficulty in handling supersaturated and wet salt particles, leading to increased maintenance and downtime costs.

Innovation Solution

The system recirculates dehumidified air to lower the relative humidity before it reaches the salt filter, reducing the likelihood of supersaturated or wet salt particles and enhancing filter efficiency and longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If outside air is used for dehumidification, then the dehumidification function is achieved, but salt particles penetrate the filter and reduce filter efficiency

Engineering Contradiction:
Improvedehumidification functionVSAvoidsalt particle penetration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-drying the outside air before it reaches the salt filter. The dehumidifier unit removes moisture from the incoming air, lowering its humidity content before filtration. This prevents supersaturated salt particles from forming on the filter, thereby maintaining filter efficiency while still achieving the required dehumidification of the interior space.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If recirculation flow is added to pretreat air, then filter efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvefilter efficiencyVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by using the dehumidifier unit to serve dual purposes: it both dehumidifies the interior space and pre-dries the outside air before filtration. The recirculation flow path allows the dehumidified air to be reused for pretreating incoming outside air, combining multiple functions into existing components rather than adding entirely new systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If salt filter is used to remove salt, then salt particles are filtered, but filter lifetime is reduced due to clogging

Engineering Contradiction:
Improvesalt particle removalVSAvoidfilter lifetime
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by pre-drying the outside air before it reaches the salt filter. The dehumidifier unit removes moisture from the incoming air, lowering its humidity content before filtration. This prevents supersaturated salt particles from forming on the filter, thereby maintaining filter efficiency while still achieving the required dehumidification of the interior space.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies beforehand cushioning by creating a protective effect through pre-drying the air. By removing moisture before the air reaches the filter, the system cushions against the formation of sticky, clogging salt particles. This protective measure extends filter lifetime by preventing the conditions that lead to rapid clogging.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 approach significantly improves the efficiency and lifespan of salt filters, reducing maintenance and repair costs by ensuring easier filtration and minimizing salt clogging, thus effectively addressing the challenges of handling salt in marine environments.

Implementation Method 1

Adsorption dehumidifiers, e.g. desiccant dehumidifiers, remove water from a volume of air that passes through it. The heart of this process could be an adsorption rotor made from or coated with a special substance that absorbs the water molecules that make up the moisture in the passing air.

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

said air intake (4) is arranged to receive outside air, and said dehumidifying arrangement (1) further comprises a recirculation flow (6) arranged to direct a portion of a flow of said desalted and dehumidified air from said dehumidifier unit (12) to said mixing unit (10)

Methodology Applied
Scientific EffectMixing:

Data Source

PatentEP2997255B1Method and arrangement for dehumidifying interior air in off-shore installations
Publication Date: 2018.09.19 COTES
  • EP2997255B1 patent drawingFigure 1
  • EP2997255B1 patent drawingFigure 2
  • EP2997255B1 patent drawingFigure 3

AI summary

The present invention concerns a method and an arrangement for dehumidifying and desalting interior air in off-shore installations. A simplified arrangement is presented wherein exterior intake air containing water rich in supersaturated and wet salt particles is pretreated with dry and salt free pretreatment air before entering a dehumidifying and de-salting unit from which the intake air exits as desalted and dehumidified exit air. A part of this desalted and dehumidified exit air is then redirected to the intake air flow path to serve as pretreatment air thereby simplifying construction and enhancing the lifetime of the dehumidifying and desalting unit.