Rotary Dehumidifier for Shipyards

Rotary Desiccant Dehumidifiers for Shipyards

The application of rotary desiccant dehumidifiers in shipyards focuses on addressing the adverse effects of high humidity environments on construction quality, equipment performance, and production efficiency during shipbuilding and repair processes. They are particularly suited to meet dehumidification demands in specialized settings such as enclosed/semi-enclosed workshops and ship compartments within shipyards.

Dry Treatment for Ship Compartments / Enclosed Cabins

Enclosed spaces like engine rooms, cargo holds, ballast water tanks, and living quarters in ships often experience humidity levels exceeding 80% RH during construction or maintenance. This is due to external rainwater infiltration and moisture accumulation from welding/cleaning activities. Rotary desiccant dehumidifiers employ a “mobile unit + duct-delivered airflow” approach to provide targeted dehumidification for single or multiple compartments. This maintains humidity within the optimal range of 40%-60% RH, establishing a dry foundation for subsequent welding and anti-corrosion coating applications.

Surface Pre-treatment Before Ship Coating

The coating quality of ship hulls and cabin interior walls directly impacts corrosion resistance (especially for ocean-going vessels exposed to seawater erosion). Moisture on the substrate (steel) surface can cause reduced coating adhesion, blistering, and peeling. Rotary desiccant dehumidifiers can integrate with pre-treatment workshop ventilation systems to rapidly reduce workshop humidity to 35%-50% RH. This prevents moisture from mixing with metal powders during compressed air rust removal/sandblasting, ensuring substrate surfaces meet the “oil-free, rust-free, moisture-free” coating standards.

Installation and Commissioning of Electrical Equipment/Control Systems

Precision electrical components such as navigation systems, communication equipment, and switchboards are highly sensitive to humidity (exceeding 65% RH may cause circuit board short circuits and reduced insulation performance). After equipment installation or maintenance, rotary desiccant dehumidifiers must dry the electrical compartments, stabilizing humidity between 30%-50% RH. This prevents moisture damage to equipment and ensures safe, efficient commissioning.

Moisture Prevention and Dehumidification During Ship Repairs / Dry Dock Periods

When ships undergo dry dock repairs during rainy seasons or high-humidity weather, condensation easily forms in enclosed spaces (particularly hull bottoms and propeller compartments), causing rust on repair welds and component corrosion. Rotary desiccant dehumidifiers serve as temporary dehumidification equipment, continuously removing moisture from the air to maintain a dry repair environment and prevent corrosion recurrence shortly after repairs.

Uncontrolled high humidity in shipyards directly leads to “quality risks + cost waste + schedule delays.” Rotary desiccant dehumidifiers address these core challenges through precise dehumidification:

Prevent steel corrosion and welding defects: High humidity accelerates steel oxidation and rusting. During welding, moisture causes porosity and cracks (known as “hydrogen-induced cracking”) in welds, compromising structural integrity. Dehumidification reduces rework rates and enhances hull safety.

Ensuring anti-corrosion coating longevity: Paint layers applied in damp environments are prone to “pinholes” and “rust reappearance,” necessitating re-sanding and re-coating, which increases material and labor costs. A dry environment allows for more uniform coating curing, extending the ship's anti-corrosion cycle (typically increasing coating lifespan by 3-5 years).

Preventing Electrical Equipment Failures: Prolonged exposure to high humidity in ship electrical systems (e.g., radar, propulsion control systems) reduces insulation resistance, causing short circuits or equipment burnout with extremely high repair costs. Dehumidification lowers electrical failure risks, ensuring safe sea trials.

Shortening construction cycles: Traditional natural ventilation dehumidification relies on weather conditions, with rainy days potentially halting painting and welding operations. Rotary desiccant dehumidifiers operate independently of external weather, enabling 24/7 continuous operation. This ensures construction progresses as scheduled, preventing project delays.

Compared to traditional air-cooled dehumidifiers and air conditioning dehumidification systems, desiccant wheel dehumidifiers demonstrate superior adaptability in the complex environments of shipyards. Their core advantages include:

Strong Adaptability to Low-Humidity Environments

Operating on the principle of “desiccant wheel + regenerative heating” (using desiccants like silica gel or molecular sieves), desiccant dehumidifiers maintain stable humidity reduction below 30% RH even in low-temperature, high-humidity conditions (e.g., winter shipyard workshops at 5-15°C and 85% RH). In contrast, conventional air-conditioning dehumidification efficiency drops significantly below 10°C.

Capable of Handling High-Humidity, Dust-laden Air

Workshop environments in shipyards (e.g., pre-treatment shops, welding shops) often contain air laden with metal dust and welding fume particles. Primary/intermediate efficiency filters can be installed at the inlet of desiccant dehumidifiers to prevent dust clogging the desiccant wheel. Simultaneously, their sealed airflow design prevents dust dispersion, effectively combining dehumidification with air purification.

Flexible deployment for confined spaces

Ship compartments feature tight spaces and winding passages, making large dehumidification equipment difficult to access. Desiccant dehumidifiers come in two forms: “mobile units” (compact size with swivel casters) and “modular units” (detachable for installation). They can be directly wheeled into compartments or connected via ductwork for dehumidification, eliminating the need for major site modifications.

Stable Operation with Low Maintenance Costs

Shipyard production environments often involve vibration and dust. Rotary desiccant dehumidifiers feature a simple mechanical structure (core components: desiccant wheel and fan) with no vulnerable parts (e.g., compressors), resulting in low failure rates. The desiccant wheel can be reused through periodic regeneration (high-temperature heating to remove moisture), eliminating frequent consumable replacements. Long-term maintenance costs are lower than traditional dehumidification equipment.